Branched-Chain Amino Acid Supplementation in Combination with Voluntary Running Improves Body Composition in Female C57BL/6 Mice

PubMed Central

Platt, Kristen M.; Charnigo, Richard J.; Shertzer, Howard G.; Pearson, Kevin J.

2016-01-01

Exercise is an inexpensive intervention that may be used to reduce obesity and its consequences. In addition, many individuals who regularly exercise utilize dietary supplements to enhance their exercise routine and to accelerate fat loss or increase lean mass. Branched-chain amino acids (BCAAs) are a popular supplement and have been shown to produce a number of beneficial effects in rodent models and humans. Therefore, we hypothesized that BCAA supplementation would protect against high fat diet (HFD)-induced glucose intolerance and obesity in mice with and without access to exercise. We subjected 80 female C57BL/6 mice to a paradigm of HFD feeding, exercise in the form of voluntary wheel running, and BCAA supplementation in the drinking water for 16 weeks (n = 10 per group). Body weight was monitored weekly, while food and water consumption were recorded twice weekly. During the 5th, 10th, and 15th weeks of treatment, glucose tolerance and body composition were analyzed. Exercise significantly improved glucose tolerance in both control-fed and HFD-fed mice. BCAA supplementation, however, did not significantly alter glucose tolerance in any treatment group. While BCAA supplements did not improve lean to fat mass ratio in sedentary mice, it significantly augmented the effects of exercise on this parameter. PMID:26716948

Resistance exercise training and the orthostatic response

NASA Technical Reports Server (NTRS)

McCarthy, J. P.; Bamman, M. M.; Yelle, J. M.; LeBlanc, A. D.; Rowe, R. M.; Greenisen, M. C.; Lee, S. M.; Spector, E. R.; Fortney, S. M.

1997-01-01

Resistance exercise has been suggested to increase blood volume, increase the sensitivity of the carotid baroreceptor cardiac reflex response (BARO), and decrease leg compliance, all factors that are expected to improve orthostatic tolerance. To further test these hypotheses, cardiovascular responses to standing and to pre-syncopal limited lower body negative pressure (LBNP) were measured in two groups of sedentary men before and after a 12-week period of either exercise (n = 10) or no exercise (control, n = 9). Resistance exercise training consisted of nine isotonic exercises, four sets of each, 3 days per week, stressing all major muscle groups. After exercise training, leg muscle volumes increased (P < 0.05) by 4-14%, lean body mass increased (P = 0.00) by 2.0 (0.5) kg, leg compliance and BARO were not significantly altered, and the maximal LBNP tolerated without pre-syncope was not significantly different. Supine resting heart rate was reduced (P = 0.03) without attenuating the heart rate or blood pressure responses during the stand test or LBNP. Also, blood volume (125I and 51Cr) and red cell mass were increased (P < 0.02) by 2.8% and 3.9%, respectively. These findings indicate that intense resistance exercise increases blood volume but does not consistently improve orthostatic tolerance.

Association between physical exercise and quality of erection in men with ischaemic heart disease and erectile dysfunction subjected to physical training.

PubMed

Kałka, Dariusz; Domagała, Zygmunt; Dworak, Jacek; Womperski, Krzysztof; Rusiecki, Lesław; Marciniak, Wojciech; Adamus, Jerzy; Pilecki, Witold

2013-01-01

In addition to a beneficial effect on exercise tolerance and an associated reduction of global cardiovascular risk, modification of physical activity has a positive effect on the quality of life, reducing, among other things, the severity of erectile dysfunction (ED). The specific nature of sexual activity, which combines the need to maintain appropriate exercise tolerance and good erection quality, prompted us to evaluate the association between exercise tolerance and severity of ED in an intervention group of subjects with ischaemic heart disease (IHD) and ED in the context of cardiac rehabilitation (CR). A total of 138 men treated invasively for IHD (including 99 treated with percutaneous coronary intervention and 39 treated with coronary artery bypass grafting) who scored 21 or less in the initial IIEF-5 test were investigated. Subjects were randomised into two groups. The study group included 103 subjects (mean age 62.07 ± 8.59 years) who were subjected to a CR cycle. The control group included 35 subjects (mean age 61.43 ± 8.81 years) who were not subjected to any CR. All subjects filled out an initial and final IIEF-5 questionnaire and were evaluated twice with a treadmill exercise test. The CR cycle was carried out for a period of 6 months and included interval endurance training on a cycle ergometer (three times a week) and general fitness exercises and resistance training (twice a week). The CR cycle in the study group resulted in a statistically significant increase in exercise tolerance (7.15 ± 1.69 vs. 9.16 ± 1.84 METs,p < 0.05) and an increase in erection quality (12.51 ± 5.98 vs. 14.39 ± 6.82, p < 0.05) which was not observed in the control group. A significant effect of age on a progressive decrease in exercise tolerance and erection quality was found in the study group. Exercise tolerance and erection quality were also negatively affected by hypertension and smoking. A significant correlation between exercise tolerance and erection quality prior to the rehabilitation cycle indicates better erection quality in patients with better effort tolerance. The improvement in exercise tolerance did not correlate significantly with initial exercise tolerance or age of the subjects. In contrast, a significantly higher increase in erection quality was observed in younger subjects with the lowest baseline severity of ED.The relative increase in exercise tolerance in the group subjected to CR was significantly higher than the relative increase in erection quality but these two effects were not significantly correlated with each other. 1. In subjects with IHD and ED, erection quality is significantly correlated with exercise tolerance. 2. Exercise training had a positive effect on both exercise tolerance and erection quality but the size of these two effects was different and they ran independently of each other.

Exercise Training During +Gz Acceleration

NASA Technical Reports Server (NTRS)

Greenleaf, J. E.; Chou, J. L.; Simonson, S. R.; Jackson, C. G. R.; Barnes, P. R.

1999-01-01

The overall purpose is to study the effect of passive (without exercise) and active (with exercise) +Gz (head-to-foot) acceleration training, using a short-arm (1.9m radius) centrifuge, on post- training maximal oxygen uptake (VO2 max, work capacity) and 70 deg head-up tilt (orthostatic) tolerance in ambulatory subjects to test the hypothesis that (a) both passive and active acceleration training will improve post-training tilt-tolerance, and (b) there will be no difference in tilt-tolerance between passive and active exercise acceleration training because increased hydrostatic and blood pressures, rather than increased muscular metabolism, will provide the major adaptive stimulus. The purpose of the pilot study was to test the hypothesis that there would be no significant difference in the metabolic responses (oxygen uptake, heart rate, pulmonary ventilation, or respiratory exchange ratio) during supine exercise with moderate +Gz acceleration.

Novel investigational drugs mimicking exercise for the treatment of cachexia.

PubMed

Penna, F; Pin, F; Ballarò, R; Baccino, F M; Costelli, P

2016-01-01

Cachexia is a syndrome characterized by body weight loss, muscle wasting and metabolic abnormalities, that frequently complicates the management of people affected by chronic diseases. No effective therapy is actually available, although several drugs are under clinical evaluation. Altered energy metabolism markedly contributes to the pathogenesis of cachexia; it can be improved by exercise, which is able to both induce anabolism and inhibit catabolism. This review focuses on exercise mimetics and their potential inclusion in combined protocols to treat cachexia. The authors pay with particular reference to the cancer-associated cachexia. Even though exercise improves muscle phenotype, most patients retain sedentary habits which are quite difficult to disrupt. Moreover, they frequently present with chronic fatigue and comorbidities that reduce exercise tolerance. For these reasons, drugs mimicking exercise could be beneficial to those who are unable to comply with the practice of physical activity. Since some exercise mimetics may exert serious side effects, further investigations should focus on treatments which maintain their effectiveness on muscle phenotype while remaining tolerable at the same time.

The link between exercise and titin passive stiffness.

PubMed

Lalande, Sophie; Mueller, Patrick J; Chung, Charles S

2017-09-01

What is the topic of this review? This review focuses on how in vivo and molecular measurements of cardiac passive stiffness can predict exercise tolerance and how exercise training can reduce cardiac passive stiffness. What advances does it highlight? This review highlights advances in understanding the relationship between molecular (titin-based) and in vivo (left ventricular) passive stiffness, how passive stiffness modifies exercise tolerance, and how exercise training may be therapeutic for cardiac diseases with increased passive stiffness. Exercise can help alleviate the negative effects of cardiovascular disease and cardiovascular co-morbidities associated with sedentary behaviour; this may be especially true in diseases that are associated with increased left ventricular passive stiffness. In this review, we discuss the inverse relationship between exercise tolerance and cardiac passive stiffness. Passive stiffness is the physical property of cardiac muscle to produce a resistive force when stretched, which, in vivo, is measured using the left ventricular end diastolic pressure-volume relationship or is estimated using echocardiography. The giant elastic protein titin is the major contributor to passive stiffness at physiological muscle (sarcomere) lengths. Passive stiffness can be modified by altering titin isoform size or by post-translational modifications. In both human and animal models, increased left ventricular passive stiffness is associated with reduced exercise tolerance due to impaired diastolic filling, suggesting that increased passive stiffness predicts reduced exercise tolerance. At the same time, exercise training itself may induce both short- and long-term changes in titin-based passive stiffness, suggesting that exercise may be a treatment for diseases associated with increased passive stiffness. Direct modification of passive stiffness to improve exercise tolerance is a potential therapeutic approach. Titin passive stiffness itself may be a treatment target based on the recent discovery of RNA binding motif 20, which modifies titin isoform size and passive stiffness. Translating these discoveries that link exercise and left ventricular passive stiffness may provide new methods to enhance exercise tolerance and treat patients with cardiovascular disease. © 2017 The Authors. Experimental Physiology © 2017 The Physiological Society.

High intensity interval exercise is an effective alternative to moderate intensity exercise for improving glucose tolerance and insulin sensitivity in adolescent boys.

PubMed

Cockcroft, Emma J; Williams, Craig A; Tomlinson, Owen W; Vlachopoulos, Dimitris; Jackman, Sarah R; Armstrong, Neil; Barker, Alan R

2015-11-01

High-intensity interval exercise (HIIE) may offer a time efficient means to improve health outcomes compared to moderate-intensity exercise (MIE). This study examined the acute effect of HIIE compared to a work-matched bout of MIE on glucose tolerance, insulin sensitivity (IS), resting fat oxidation and exercise enjoyment in adolescent boys. Within-measures design with counterbalanced experimental conditions. Nine boys (14.2 ± 0.4 years) completed three conditions on separate days in a counterbalanced order: (1) HIIE; (2) work matched MIE, both on a cycle ergometer; and (3) rest (CON). An oral glucose tolerance test (OGTT) was performed after exercise or rest and the area under curve (AUC) responses for plasma [glucose] and [insulin] were calculated, and IS estimated (Cederholm index). Energy expenditure and fat oxidation were measured following the OGTT using indirect calorimetry. Exercise enjoyment was assessed using the Physical Activity Enjoyment Scale. The incremental AUC (iAUC) for plasma [glucose] was reduced following both MIE (-23.9%, P = 0.013, effect size [ES] = -0.64) and HIIE (-28.9%, P=0.008, ES = -0.84) compared to CON. The iAUC for plasma [insulin] was lower for HIIE (-24.2%, P = 0.021, ES = -0.71) and MIE (-29.1%, P = 0.012, ES = -0.79) compared to CON. IS increased by 11.2% after HIIE (P = 0.03, ES = 0.76) and 8.4% after MIE (P = 0.10, ES = 0.58). There was a trend for an increase in fat oxidation following HIIE (P = 0.097, ES = 0.70). Both HIIE and MIE were rated as equally enjoyable (P > 0.05, ES < 0.01). A single bout of time efficient HIIE is an effective alternative to MIE for improving glucose tolerance and IS in adolescent boys immediately after exercise. Copyright © 2014 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Oral N-acetylcysteine and exercise tolerance in mild chronic obstructive pulmonary disease.

PubMed

Hirai, Daniel M; Jones, Joshua H; Zelt, Joel T; da Silva, Marianne L; Bentley, Robert F; Edgett, Brittany A; Gurd, Brendon J; Tschakovsky, Michael E; O'Donnell, Denis E; Neder, J Alberto

2017-05-01

Heightened oxidative stress is implicated in the progressive impairment of skeletal muscle vascular and mitochondrial function in chronic obstructive pulmonary disease (COPD). Whether accumulation of reactive oxygen species contributes to exercise intolerance in the early stages of COPD is unknown. The purpose of the present study was to determine the effects of oral antioxidant treatment with N -acetylcysteine (NAC) on respiratory, cardiovascular, and locomotor muscle function and exercise tolerance in patients with mild COPD. Thirteen patients [forced expiratory volume in 1 s (FEV 1 )-to-forced vital capacity ratio < lower limit of normal (LLN) and FEV 1 ≥ LLN) were enrolled in a double-blind, randomized crossover study to receive NAC (1,800 mg/day) or placebo for 4 days. Severe-intensity constant-load exercise tests were performed with noninvasive measurements of central hemodynamics (stroke volume, heart rate, and cardiac output via impedance cardiography), arterial blood pressure, pulmonary ventilation and gas exchange, quadriceps muscle oxygenation (near-infrared spectroscopy), and estimated capillary blood flow. Nine patients completed the study with no major adverse clinical effects. Although NAC elevated plasma glutathione by ~27% compared with placebo ( P < 0.05), there were no differences in exercise tolerance (placebo: 325 ± 47 s, NAC: 336 ± 51 s), central hemodynamics, arterial blood pressure, pulmonary ventilation or gas exchange, locomotor muscle oxygenation, or capillary blood flow from rest to exercise between conditions ( P > 0.05 for all). In conclusion, modulation of plasma redox status with oral NAC treatment was not translated into beneficial effects on central or peripheral components of the oxygen transport pathway, thereby failing to improve exercise tolerance in nonhypoxemic patients with mild COPD. NEW & NOTEWORTHY Acute antioxidant treatment with N -acetylcysteine (NAC) elevated plasma glutathione but did not modulate central or peripheral components of the O 2 transport pathway, thereby failing to improve exercise tolerance in patients with mild chronic obstructive pulmonary disease (COPD). Copyright © 2017 the American Physiological Society.

Benefits of supplemental oxygen in exercise training in nonhypoxemic chronic obstructive pulmonary disease patients.

PubMed

Emtner, Margareta; Porszasz, Janos; Burns, Mary; Somfay, Attila; Casaburi, Richard

2003-11-01

Supplemental oxygen improves exercise tolerance of normoxemic and hypoxemic chronic obstructive pulmonary disease (COPD) patients. We determined whether nonhypoxemic COPD patients undergoing exercise training while breathing supplemental oxygen achieve higher intensity and therefore improve exercise capacity more than patients breathing air. A double-blinded trial was performed involving 29 nonhypoxemic patients (67 years, exercise SaO2 > 88%) with COPD (FEV1 = 36% predicted). All exercised on cycle ergometers for 45 minutes, 3 times per week for 7 weeks at high-intensity targets. During exercise, they received oxygen (3 L/minute) (n = 14) or compressed air (3 L/minute) (n = 15). Both groups had a higher exercise tolerance after training and when breathing oxygen. However, the oxygen-trained group increased the training work rate more rapidly than the air-trained group. The mean +/- SD work rate during the last week was 62 +/- 19 W (oxygen-trained group) and 52 +/- 22 W (air-trained group) (p < 0.01). After training, endurance in constant work rate tests increased more in the oxygen-trained group (14.5 minutes) than in the air-trained group (10.5 minutes) (p < 0.05). At isotime, the breathing rate decreased four breaths per minute in the oxygen-trained group and one breath per minute in the air-trained group (p = 0.001). We conclude that supplemental oxygen provided during high-intensity training yields higher training intensity and evidence of gains in exercise tolerance in laboratory testing.

Clinical Utility of Exercise Training in Heart Failure with Reduced and Preserved Ejection Fraction

PubMed Central

Asrar Ul Haq, Muhammad; Goh, Cheng Yee; Levinger, Itamar; Wong, Chiew; Hare, David L

2015-01-01

Reduced exercise tolerance is an independent predictor of hospital readmission and mortality in patients with heart failure (HF). Exercise training for HF patients is well established as an adjunct therapy, and there is sufficient evidence to support the favorable role of exercise training programs for HF patients over and above the optimal medical therapy. Some of the documented benefits include improved functional capacity, quality of life (QoL), fatigue, and dyspnea. Major trials to assess exercise training in HF have, however, focused on heart failure with reduced ejection fraction (HFREF). At least half of the patients presenting with HF have heart failure with preserved ejection fraction (HFPEF) and experience similar symptoms of exercise intolerance, dyspnea, and early fatigue, and similar mortality risk and rehospitalization rates. The role of exercise training in the management of HFPEF remains less clear. This article provides a brief overview of pathophysiology of reduced exercise tolerance in HFREF and heart failure with preserved ejection fraction (HFPEF), and summarizes the evidence and mechanisms by which exercise training can improve symptoms and HF. Clinical and practical aspects of exercise training prescription are also discussed. PMID:25698883

Musical Agency during Physical Exercise Decreases Pain.

PubMed

Fritz, Thomas H; Bowling, Daniel L; Contier, Oliver; Grant, Joshua; Schneider, Lydia; Lederer, Annette; Höer, Felicia; Busch, Eric; Villringer, Arno

2017-01-01

Objectives: When physical exercise is systematically coupled to music production, exercisers experience improvements in mood, reductions in perceived effort, and enhanced muscular efficiency. The physiology underlying these positive effects remains unknown. Here we approached the investigation of how such musical agency may stimulate the release of endogenous opioids indirectly with a pain threshold paradigm. Design: In a cross-over design we tested the opioid-hypothesis with an indirect measure, comparing the pain tolerance of 22 participants following exercise with or without musical agency. Method: Physical exercise was coupled to music by integrating weight-training machines with sensors that control music-synthesis in real time. Pain tolerance was measured as withdrawal time in a cold pressor test. Results: On average, participants tolerated cold pain for ~5 s longer following exercise sessions with musical agency. Musical agency explained 25% of the variance in cold pressor test withdrawal times after factoring out individual differences in general pain sensitivity. Conclusions: This result demonstrates a substantial pain reducing effect of musical agency in combination with physical exercise, probably due to stimulation of endogenous opioid mechanisms. This has implications for exercise endurance, both in sports and a multitude of rehabilitative therapies in which physical exercise is effective but painful.

Musical Agency during Physical Exercise Decreases Pain

PubMed Central

Fritz, Thomas H.; Bowling, Daniel L.; Contier, Oliver; Grant, Joshua; Schneider, Lydia; Lederer, Annette; Höer, Felicia; Busch, Eric; Villringer, Arno

2018-01-01

Objectives: When physical exercise is systematically coupled to music production, exercisers experience improvements in mood, reductions in perceived effort, and enhanced muscular efficiency. The physiology underlying these positive effects remains unknown. Here we approached the investigation of how such musical agency may stimulate the release of endogenous opioids indirectly with a pain threshold paradigm. Design: In a cross-over design we tested the opioid-hypothesis with an indirect measure, comparing the pain tolerance of 22 participants following exercise with or without musical agency. Method: Physical exercise was coupled to music by integrating weight-training machines with sensors that control music-synthesis in real time. Pain tolerance was measured as withdrawal time in a cold pressor test. Results: On average, participants tolerated cold pain for ~5 s longer following exercise sessions with musical agency. Musical agency explained 25% of the variance in cold pressor test withdrawal times after factoring out individual differences in general pain sensitivity. Conclusions: This result demonstrates a substantial pain reducing effect of musical agency in combination with physical exercise, probably due to stimulation of endogenous opioid mechanisms. This has implications for exercise endurance, both in sports and a multitude of rehabilitative therapies in which physical exercise is effective but painful. PMID:29387030

Effect of dietary nitrate supplementation on tolerance to supramaximal intensity intermittent exercise.

PubMed

Aucouturier, Julien; Boissière, Julien; Pawlak-Chaouch, Mehdi; Cuvelier, Grégory; Gamelin, François-Xavier

2015-09-15

Dietary nitrate (NO3(-)) supplementation has been shown to increase exercise tolerance and improve oxidative efficiency during aerobic exercise in healthy subjects. We tested the hypothesis that a 3-day supplementation in beetroot juice (BJ) rich in NO3(-) would improve the tolerance to supramaximal intensity intermittent exercise consisting of 15-s exercise periods at 170% of the maximal aerobic power interspersed with 30-s passive recovery periods. The number of repetitions completed before reaching volitional exhaustion was significantly higher in the BJ than in the placebo condition (26.1 ± 10.7 versus 21.8 ± 8.0 respectively, P < 0.05). In contrast to previous findings during exercise performed at intensity below the peak oxygen uptake (VO2peak), oxygen uptake (VO2) was unaffected (BJ: 2735 ± 345 mL kg(-1) min(-1) vs. placebo: 2787 ± 346 mL kg(-1) min(-1), NS). However, the Area Under the Curve for microvascular total hemoglobin (AUC-THb) in the vastus lateralis muscle assessed by near infrared spectroscopy during 3 time-matched repetitions was significantly increased with NO3(-) supplementation (BJ: 9662 ± 1228 a.u. vs. placebo:8178 ± 1589 a.u.; P < 0.05). Thus, increased NO3(-) (BJ: 421.5 ± 107.4 μM vs placebo:39.4 ± 18.0 μM) and NO2(-) (BJ: 441 ± 184 nM vs placebo: 212 ± 119 nM) plasma levels (P < 0.001 for both) are associated with improved muscle microvascular Red Blood Cell (RBC) concentration and O2 delivery during intense exercise, despite no effect on resting femoral artery blood flow, and vascular conductance. Maximal voluntary force during an isometric leg extensor exercise, and blood lactate levels were also unaffected by NO3(-) supplementation. To conclude, dietary NO3(-) supplementation enhances tolerance to exercise at supramaximal intensity, with increased microvascular total RBC concentration in the working muscle, in the absence of effect on contractile function and resting hemodynamic parameters. Copyright © 2015 Elsevier Inc. All rights reserved.

Fasting hyperglycaemia blunts the reversal of impaired glucose tolerance after exercise training in obese older adults.

PubMed

Malin, S K; Kirwan, J P

2012-09-01

Lifestyle modification, consisting of exercise and weight loss, delays the progression from prediabetes to type 2 diabetes (T2D). However, no study has determined the efficacy of exercise training on glucose metabolism in the different prediabetes subtypes. Seventy-six older (65.1 ± 0.6 years) obese adults with impaired fasting glucose (IFG; n = 12), impaired glucose tolerance (IGT; n = 9) and combined glucose intolerance (IFG + IGT = CGI; n = 22) were compared with normal glucose tolerant (NGT; n = 15) and T2D (n = 18) groups after 12 weeks of exercise training (60 min/day for 5 days/week at ~85% HR(max)). An oral glucose tolerance test was used to assess glucose levels. Insulin sensitivity (IS; euglycaemic hyperinsulinaemic clamp at 40 mU/m(2)/min), β-cell function (glucose-stimulated insulin secretion corrected for IS), body composition (hydrostatic weighing/computed tomography scan) and cardiovascular fitness (treadmill VO(2) max) were also assessed. Exercise training reduced weight and increased cardiovascular fitness (p < 0.05). Exercise training lowered fasting glucose levels in IFG, CGI and T2D (p < 0.05) and 2-h glucose levels in IGT, CGI and T2D (p < 0.05). However, 2-h glucose levels were not normalized in adults with CGI compared with IGT (p < 0.05). β-Cell function improved similarly across groups (p < 0.05). Although not statistically significant, IS increased approximately 40% in IFG and IGT, but only 17% in CGI. The magnitude of improvement in glucose metabolism after 12 weeks of exercise training is not uniform across the prediabetes subtypes. Given the high risk of progressing to T2D, adults with CGI may require more aggressive therapies to prevent diabetes. © 2012 Blackwell Publishing Ltd.

Effects of exercise-based cardiac rehabilitation in patients after percutaneous coronary intervention: A meta-analysis of randomized controlled trials

PubMed Central

Yang, Xinyu; Li, Yanda; Ren, Xiaomeng; Xiong, Xingjiang; Wu, Lijun; Li, Jie; Wang, Jie; Gao, Yonghong; Shang, Hongcai; Xing, Yanwei

2017-01-01

In this study, we assessed the effect of rehabilitation exercise after percutaneous coronary intervention (PCI) in patients with coronary heart disease (CHD). We performed a meta-analysis to determine the effects of exercise in patients after PCI. The Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, the Embase database, China National Knowledge Internet (CNKI), China Biology Medicine (CBM), and the Wanfang Database were searched for randomized controlled trials (RCTs). The key words used for the searches were PCI, exercise, walking, jogging, Tai Chi, and yoga. Six studies with 682 patients met our inclusion criteria; we chose the primary endpoint events of cardiac death, recurrence of myocardial infarction (MI), repeated PCI, coronary artery bypass grafting (CABG), and restenosis, and the secondary endpoint measures included recurrent angina, treadmill exercise (total exercise time, ST-segment decline, angina, and maximum exercise tolerance). The results showed that exercise was not clearly associated with reductions in cardiac death, recurrence of MI, repeated PCI, CABG, or restenosis. However, the exercise group exhibited greater improvements in recurrent angina, total exercise time, ST-segment decline, angina, and maximum exercise tolerance than did the control group. Future studies need to expand the sample size and improve the quality of reporting of RCTs. PMID:28303967

Effects of a 6-Week Aquatic Treadmill Exercise Program on Cardiorespiratory Fitness and Walking Endurance in Subacute Stroke Patients: A PILOT TRIAL.

PubMed

Han, Eun Young; Im, Sang Hee

2017-03-15

To assess the feasibility and safety of a 6-week course of water walking performed using a motorized aquatic treadmill in individuals with subacute stroke for cardiorespiratory fitness, walking endurance, and activities of daily living. Twenty subacute stroke patents were randomly assigned to aquatic treadmill exercise (ATE) or land-based exercise (LBE). The ATE group (n = 10) performed water-based aerobic exercise on a motorized aquatic treadmill, and the LBE group (n = 10) performed land-based aerobic exercise on a cycle ergometer. Both groups performed aerobic exercise for 30 minutes, 5 times per week for 6 weeks. Primary outcome measures were 6-minute walk test for walking endurance and cardiopulmonary fitness parameters of a symptom-limited exercise tolerance test, and secondary measures were Korean version of the Modified Barthel Index (K-MBI) for activities of daily living. All variables were assessed at baseline and at the end of the intervention. The ATE group showed significant improvements in 6-minute walk test (P = .005), peak oxygen uptake (V·o2peak; P = .005), peak heart rate (P = .007), exercise tolerance test duration (P = .005), and K-MBI (P = .008). The LBE group showed a significant improvement only in K-MBI (P = .012). In addition, improvement in V·o2peak was greater in the ATE than in the LBE group. This preliminary study showed that a 6-week ATE program improved peak aerobic capacity and walking endurance in patients with subacute stroke. The improvement in V·o2peak after an ATE exercise program was greater than that observed after an LBE program. Therefore, ATE effectively improves cardiopulmonary fitness in patients with subacute stroke.

Maternal low intensity physical exercise prevents obesity in offspring rats exposed to early overnutrition.

PubMed

Ribeiro, Tatiane Aparecida; Tófolo, Laize Peron; Martins, Isabela Peixoto; Pavanello, Audrei; de Oliveira, Júlio Cezar; Prates, Kelly Valério; Miranda, Rosiane Aparecida; da Silva Franco, Claudinéia Conationi; Gomes, Rodrigo Mello; Francisco, Flávio Andrade; Alves, Vander Silva; de Almeida, Douglas Lopes; Moreira, Veridiana Mota; Palma-Rigo, Kesia; Vieira, Elaine; Fabricio, Gabriel Sergio; da Silva Rodrigues, Marcos Ricardo; Rinaldi, Wilson; Malta, Ananda; de Freitas Mathias, Paulo Cezar

2017-08-09

Low intensity exercise during pregnancy and lactation may create a protective effect against the development of obesity in offspring exposed to overnutrition in early life. To test these hypotheses, pregnant rats were randomly assigned into 2 groups: Sedentary and Exercised, low intensity, on a rodent treadmill at 30% VO 2Max /30-minute/session/3x/week throughout pregnancy and the lactation. Male offspring were raised in small litters (SL, 3 pups/dam) and normal litters (NL, 9 pups/dam) as models of early overnutrition and normal feed, respectively. Exercised mothers showed low mesenteric fat pad stores and fasting glucose and improved glucose-insulin tolerance, VO 2max during lactation and sympathetic activity. Moreover, the breast milk contained elevated levels of insulin. In addition, SL of sedentary mothers presented metabolic dysfunction and glucose and insulin intolerance and were hyperglycemic and hyperinsulinemic in adulthood. SL of exercised mothers showed lower fat tissue accretion and improvements in glucose tolerance, insulin sensitivity, insulinemia and glycemia. The results suggest that maternal exercise during the perinatal period can have a possible reprogramming effect to prevent metabolic dysfunction in adult rat offspring exposed to early overnutrition, which may be associated with the improvement in maternal health caused by exercise.

Is high-intensity interval training a time-efficient exercise strategy to improve health and fitness?

PubMed

Gillen, Jenna B; Gibala, Martin J

2014-03-01

Growing research suggests that high-intensity interval training (HIIT) is a time-efficient exercise strategy to improve cardiorespiratory and metabolic health. "All out" HIIT models such as Wingate-type exercise are particularly effective, but this type of training may not be safe, tolerable or practical for many individuals. Recent studies, however, have revealed the potential for other models of HIIT, which may be more feasible but are still time-efficient, to stimulate adaptations similar to more demanding low-volume HIIT models and high-volume endurance-type training. As little as 3 HIIT sessions per week, involving ≤10 min of intense exercise within a time commitment of ≤30 min per session, including warm-up, recovery between intervals and cool down, has been shown to improve aerobic capacity, skeletal muscle oxidative capacity, exercise tolerance and markers of disease risk after only a few weeks in both healthy individuals and people with cardiometabolic disorders. Additional research is warranted, as studies conducted have been relatively short-term, with a limited number of measurements performed on small groups of subjects. However, given that "lack of time" remains one of the most commonly cited barriers to regular exercise participation, low-volume HIIT is a time-efficient exercise strategy that warrants consideration by health practitioners and fitness professionals.

Influence of dietary nitrate supplementation on physiological and cognitive responses to incremental cycle exercise.

PubMed

Thompson, Kevin G; Turner, Louise; Prichard, Jonathon; Dodd, Fiona; Kennedy, David O; Haskell, Crystal; Blackwell, James R; Jones, Andrew M

2014-03-01

Dietary inorganic nitrate supplementation causes physiological effects which may enhance exercise tolerance. However it is not known whether nitrate might alter cognitive function during exercise. In a double-blind, cross-over study, sixteen subjects ingested either nitrate-rich beetroot juice or a placebo and completed a continuous cycle exercise test involving 20min stages at 50% and 70% V˙O2peak and a final stage at 90% V˙O2peak until volitional exhaustion. Cognitive tasks were completed before, during and after exercise. In the dietary nitrate condition: plasma [nitrite] increased (p<0.01), systolic blood pressure decreased (p<0.05) and there was a trend for a reduced oxygen uptake at 50% V˙O2peak. Tissue oxygenation improved across exercise intensities and exercise tolerance was greater at 90% V˙O2peak (p<0.05). Rating of perceived exertion, energy levels and cognitive performance were similar between conditions with mental fatigue being evident from 70% V˙O2peak onwards (p<0.05). Dietary nitrate supplementation enhanced short-term endurance exercise performance with concomitant mental fatigue but did not improve cognitive performance post-fatigue. Copyright © 2014 Elsevier B.V. All rights reserved.

[Effect of atorvastatin on exercise tolerance in patients with diastolic dysfunction and exercise-induced hypertension].

PubMed

Ye, Ping-xian; Ye, Ping-zhen; Zhu, Jian-hua; Chen, Wei; Gao, Dan-chen

2014-05-01

To investigate the effect of atorvastatin on exercise tolerance in patients with diastolic dysfunction and exercise-induced hypertension. A randomized, double-blind, placebo-controlled prospective study was performed. Sixty patients with diastolic dysfunction (mitral flow velocity E/A <1) and exercise-induced hypertension (SBP>200 mm Hg) treated with atorvastatin (20 mg q.d) or placebo for 1 year. Cardiopulmonary exercise test and exercise blood pressure measurement were performed. Plasma B-natriuretic peptide (BNP) concentration at rest and at peak exercise, plasma high sensitive-C reaction protein (hs-CRP) and endothelin (ET) concentration were determined at baseline and after treatment. After treatment by atorvastatin, the resting SBP, pulse pressure, the peak exercise SBP and BNP were significantly decreased; and the exercise time, metabolic equivalent, maximal oxygen uptake and anaerobic threshold were increased. All of these parameters had significant differences with baseline levels (P<0.05) and the rest pulse pressure, the peak exercise SBP and BNP, and the exercise time had significant differences compared with placebo treatment (P<0.05). Plasma concentrations of hs-CRP and ET were markedly reduced by atorvastatin treatment compared with baseline and placebo (P<0.05). No difference in above parameters was found before and after placebo treatment (P>0.05). In patients with diastolic dysfunction at rest and exercise-induced hypertension, atorvastatin can effectively reduce plasma hs-CRP and ET level, lower blood pressure and peak exercise SBP, decrease peak exercise plasma BNP concentration, and ultimately improve exercise tolerance.

+Gz tolerance after 14 days bed rest and the effects of rehydration.

NASA Technical Reports Server (NTRS)

Greenleaf, J. E.; Van Beaumont, W.; Bernauer, E. M.; Haines, R. F.; Sandler, H.; Young, H. L.; Yusken, J. W.

1972-01-01

Measurement of the reduction in centrifugation tolerance after two weeks of bedrest with moderate daily exercise, with an attempt to determine if rehydration improves +Gz tolerance. There were significant reductions in +Gz tolerance during bedrest periods at three acceleration levels. Rehydration resulted in a significant increase in tolerance at 2.1G but it did not restore tolerance to control levels. Rehydration did not affect tolerance at 3.2G and 3.8G.

Physical Exercise as Therapy for Frailty.

PubMed

Aguirre, Lina E; Villareal, Dennis T

2015-01-01

Longitudinal studies demonstrate that regular physical exercise extends longevity and reduces the risk of physical disability. Decline in physical activity with aging is associated with a decrease in exercise capacity that predisposes to frailty. The frailty syndrome includes a lowered activity level, poor exercise tolerance, and loss of lean body and muscle mass. Poor exercise tolerance is related to aerobic endurance. Aerobic endurance training can significantly improve peak oxygen consumption by ∼10-15%. Resistance training is the best way to increase muscle strength and mass. Although the increase in muscle mass in response to resistance training may be attenuated in frail older adults, resistance training can significantly improve muscle strength, particularly in institutionalized patients, by ∼110%. Because both aerobic and resistance training target specific components of frailty, studies combining aerobic and resistance training provide the most promising evidence with respect to successfully treating frailty. At the molecular level, exercise reduces frailty by decreasing muscle inflammation, increasing anabolism, and increasing muscle protein synthesis. More studies are needed to determine which exercises are best suited, most effective, and safe for this population. Based on the available studies, an individualized multicomponent exercise program that includes aerobic activity, strength exercises, and flexibility is recommended to treat frailty. © 2015 Michael E. DeBakey VA Medical Center (US Government) Published by S. Karger AG, Basel.

Real-life feasibility and effectiveness of home-based pulmonary rehabilitation in chronic obstructive pulmonary disease requiring medical equipment.

PubMed

Coquart, Jérémy B; Le Rouzic, Olivier; Racil, Ghazi; Wallaert, Benoit; Grosbois, Jean-Marie

2017-01-01

Pulmonary rehabilitation (PR) is a key treatment of chronic obstructive pulmonary disease (COPD) but studies are still needed to identify the most pertinent criteria to personalize this intervention and improve its efficacy. This real-life retrospective study compared the effects of home-based PR on exercise tolerance, anxiety, depression, and health-related quality of life (HRQoL) in COPD patients, according to their medical equipment. Exercise tolerance, anxiety, depression, and HRQoL were evaluated in 109 patients equipped with long-term oxygen therapy (LTOT), 84 patients with noninvasive ventilation (NIV), 25 patients with continuous positive airway pressure (CPAP), and 80 patients with no equipment (NE), before, just after, and 6 and 12 months after PR. At baseline, the body mass index in the CPAP and NIV groups was higher ( p <0.05) than in the other two groups, and the forced expiratory volume in 1 second was lower in the LTOT and NIV groups ( p <0.001). All parameters improved after PR in the four groups ( p <0.05), but for exercise tolerance, only the 6-minute stepper test showed maintained improvement after 6 and 12 months, whereas the 10 times sit-to-stand and timed up-and-go tests were only improved just after PR. At every time point, exercise tolerance was lower in the LTOT group ( p <0.05), with a similar trend in the NIV group. Despite differences in the medical equipment to treat COPD, home-based PR showed comparable feasibility, safety, and efficacy in all equipment-based groups. Medical equipment should therefore not be a barrier to home-based PR.

[High-dose Crataegus extract WS 1442 in the treatment of NYHA stage II heart failure].

PubMed

Tauchert, M; Gildor, A; Lipinski, J

1999-10-01

The efficacy and tolerance of the standardized hawthorn (crataegus) extract WS 1442 were tested in a multicenter utilization observational study. We monitored 1,011 patients with cardiac insufficiency stage NYHA II, treated with this extract (Crataegutt novo 450, 1 tablet b.i.d.) over a period of 24 weeks. During and at the end of the observation period a significant improvement in clinical symptoms (reduced performance in the exercise tolerance test, fatigue, palpitation and exercise dyspnea) was observed. Ankle edema and nocturia disappeared by 83%, and by half of the patients respectively manifesting these symptoms before treatment. The improvement and economization of cardiac performance were additionally shown by a reduction in blood pressure, an increased maximal exercise tolerance and a reduction in the difference in the pressure/heart rate product (PHRP). The positive effects of WS 1442 were further demonstrated by an improved ejection fraction and an increased percentile shortening fraction measured using M-mode echocardiography. The stabilizing effect of the hawthorn extract on the heart rate was shown by a slower rest pulse, as well as by an increase in the number of day and night normorhythmic patients, as documented by long-term ECG. The reduction in the number of patients showing ST depressions, arrhythmias and ventricular extrasystoles at the maximum exercise level is regarded as an indication for an improved myocardial perfusion. Fourteen side effects were noted. In two cases (abdominal discomfort and facial pains accompanied by tachycardia) a possible relationship with the hawthorn therapy, was postulated which however was considered unlikely by the treating physicians. Almost 2/3 of the patients felt better or much better following the 24 weeks of treatment. More than 3/4 of the participating physicians noted a good or a very good efficacy, and 98.7% noted a good or a very good tolerance. High-dose hawthorn therapy is an efficient, well-tolerated and easily regulated therapeutic alternative for patients suffering from cardiac insufficiency stage NYHA II.

Tocotrienols and Whey Protein Isolates Substantially Increase Exercise Endurance Capacity in Diet -Induced Obese Male Sprague-Dawley Rats

PubMed Central

Aguila, Jay; McConell, Glenn K.; McAinch, Andrew J.; Mathai, Michael L.

2016-01-01

Background and Aims Obesity and impairments in metabolic health are associated with reductions in exercise capacity. Both whey protein isolates (WPIs) and vitamin E tocotrienols (TCTs) exert favorable effects on obesity-related metabolic parameters. This research sought to determine whether these supplements improved exercise capacity and increased glucose tolerance in diet-induced obese rats. Methods Six week old male rats (n = 35) weighing 187 ± 32g were allocated to either: Control (n = 9), TCT (n = 9), WPI (n = 8) or TCT + WPI (n = 9) and placed on a high-fat diet (40% of energy from fat) for 10 weeks. Animals received 50mg/kg body weight and 8% of total energy intake per day of TCTs and/or WPIs respectively. Food intake, body composition, glucose tolerance, insulin sensitivity, exercise capacity, skeletal muscle glycogen content and oxidative enzyme activity were determined. Results Both TCT and WPI groups ran >50% longer (2271 ± 185m and 2195 ± 265m respectively) than the Control group (1428 ± 139m) during the run to exhaustion test (P<0.05), TCT + WPI did not further improve exercise endurance (2068 ± 104m). WPIs increased the maximum in vitro activity of beta-hydroxyacyl-CoA in the soleus muscle (P<0.05 vs. Control) but not in the plantaris. Citrate synthase activity was not different between groups. Neither supplement had any effect on weight gain, adiposity, glucose tolerance or insulin sensitivity. Conclusion Ten weeks of both TCTs and WPIs increased exercise endurance by 50% in sedentary, diet-induced obese rats. These positive effects of TCTs and WPIs were independent of body weight, adiposity or glucose tolerance. PMID:27058737

Optimizing the "priming" effect: influence of prior exercise intensity and recovery duration on O2 uptake kinetics and severe-intensity exercise tolerance.

PubMed

Bailey, Stephen J; Vanhatalo, Anni; Wilkerson, Daryl P; Dimenna, Fred J; Jones, Andrew M

2009-12-01

It has been suggested that a prior bout of high-intensity exercise has the potential to enhance performance during subsequent high-intensity exercise by accelerating the O(2) uptake (Vo(2)) on-response. However, the optimal combination of prior exercise intensity and subsequent recovery duration required to elicit this effect is presently unclear. Eight male participants, aged 18-24 yr, completed step cycle ergometer exercise tests to 80% of the difference between the preestablished gas exchange threshold and maximal Vo(2) (i.e., 80%Delta) after no prior exercise (control) and after six different combinations of prior exercise intensity and recovery duration: 40%Delta with 3 min (40-3-80), 9 min (40-9-80), and 20 min (40-20-80) of recovery and 70%Delta with 3 min (70-3-80), 9 min (70-9-80), and 20 min (70-20-80) of recovery. Overall Vo(2) kinetics were accelerated relative to control in all conditions except for 40-9-80 and 40-20-80 conditions as a consequence of a reduction in the Vo(2) slow component amplitude; the phase II time constant was not significantly altered with any prior exercise/recovery combination. Exercise tolerance at 80%Delta was improved by 15% and 30% above control in the 70-9-80 and 70-20-80 conditions, respectively, but was impaired by 16% in the 70-3-80 condition. Prior exercise at 40%Delta did not significantly influence exercise tolerance regardless of the recovery duration. These data demonstrate that prior high-intensity exercise ( approximately 70%Delta) can enhance the tolerance to subsequent high-intensity exercise provided that it is coupled with adequate recovery duration (>or=9 min). This combination presumably optimizes the balance between preserving the effects of prior exercise on Vo(2) kinetics and providing sufficient time for muscle homeostasis (e.g., muscle phosphocreatine and H(+) concentrations) to be restored.

Supported treadmill ambulation for amyotrophic lateral sclerosis: a pilot study.

PubMed

Sanjak, Mohammed; Bravver, Elena; Bockenek, William L; Norton, H James; Brooks, Benjamin R

2010-12-01

To determine the feasibility, tolerability, safety, and exercise treatment-effect size of repetitive rhythmic exercise mediated by supported treadmill ambulation training (STAT) for patients with amyotrophic lateral sclerosis (ALS). Interventional with repeated-measures design. Multidisciplinary ALS clinic at academic medical center. Convenience sample of patients with ALS (N=9) who were ambulatory with assistive devices (Sinaki-Mulder stages II-III). Repetitive rhythmic exercise-STAT (30min total; 5min of exercise intercalated with 5min of rest) performed 3 times a week for 8 weeks. ALS Functional Rating Scale-Revised (ALSFRS-R), percentage of predicted vital capacity (VC), total lower-extremities manual muscle test (MMT), rate of perceived exertion (RPE), Fatigue Severity Scale (FSS), and maximum voluntary isometric contraction (MVIC) in 10 lower and 10 upper extremities. Gait performance, which included walking distance, speed, steps, and stride length, was evaluated during treadmill and ground 6-minute walk tests (6MWTs) and 25-foot walk test (25FWT). Feasibility issues decreased screened participants by 4 patients (31%). Nine patients were enrolled, but 6 patients (67%) completed the study and 3 (23% of original cohort; 33% of enrolled cohort) could not complete the exercise intervention because of non-ALS-related medical problems. Tolerability of the intervention measures during the treadmill 6MWT showed improvement in RPE (P≤.05) and FSS score (P≥.05). Safety measures (ALSFRS-R, VC, MMT) showed no decrease and showed statistical improvement in ALSFRS-R score (P≤.05) during the study interval. Exercise treatment-effect size showed variable improvements. Gait speed, distance, and stride length during the treadmill 6MWT improved significantly (P≤.05) after 4 weeks and improvements were maintained after 8 weeks compared with baseline. Walking distance during the ground 6MWT increased significantly after 4 weeks and was maintained after 8 weeks compared with baseline (P≤.05). Walking speed during the 25FWT and lower-extremity MVIC improved, but were not statistically significant. Repetitive rhythmic exercise-STAT is feasible, tolerated, and safe for patients with ALS. Repetitive rhythmic exercise-STAT treatment-effect size across a number of ALS-related measures was consistent with improved work capacity and gait function in patients with ALS who are dependent on assistive devices for ambulation. Repetitive rhythmic exercise-STAT should be evaluated further in larger studies to determine the stability of this improved function in relation to the rate of progression of the underlying ALS. Copyright © 2010 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Exercise tolerance and selected motor skills in young females with idiopathic scoliosis treated with different physiotherapeutic methods.

PubMed

Fabian, Krzysztof Marek; Rożek-Piechura, Krystyna

2014-01-01

Scoliosis is a disorder that leads to dysfunction of a number of systems in the body, especially in young females. Physical capacity is one of the most important elements of good health as well as ofbiological development. Adolescence is a time when physical capacity develops intensively, and the condition of the respiratory system is one of many factors that have an impact on the level of physical capacity. This paper aims to evaluate a short-term application of two methods of physiotherapy and their influence on the level of exercise tolerance in young females suffering from idiopathic scoliosis. The study involved a group of 49 young females aged 14-15 years diagnosed with (2040°) thoracic and lumbar scoliosis who were in-patients at the rehabilitation ward of the Regional Paediatric Rehabilitation Hospital in Jastrzębie Zdrój. The group was divided into two subgroups depending on the method of rehabilitation employed: the first subgroup received asymmetric breathing exercise therapy by Dobosiewicz and the second subgroup practised symmetric remedial exercises. Cobb's angle, the degree of skeletal maturity, i.e. the Risser sign and the degree trunk rotation of the apex of the curvature by means of Raimondi's coefficient were determined once in an x-ray image. Basic somatic features, maximal voluntary ventilation (MVV parameter), selected motor skills and exercise tolerance were assessed on two occasions (before beginning and after completion of the rehabilitation treatment). 1. Young females suffering from (20-40°) thoracic and lumbar scoliosis demonstrate respiratory dysfunction, as shown by decreased maximal voluntary ventilation (MVV) in the two subgroups in the present study. Exercises according to Dobosiewicz's method brought about a significantly higher degree of improvement in this parameter. 2. The physiotherapeutic regimen administered to the young girls with scoliosis significantly improved their strength motor skills and exercise tolerance. A significantly higher improvement was observed in the subgroup treated using Dobosiewicz's method, in particular, in the strength of abdominal muscles, which play an important role in both respiratory function and body posture maintenance.

Exercise Self-Efficacy Moderates the Relation between Anxiety Sensitivity and Body Mass Index and Exercise Tolerance in Treatment-Seeking Smokers

PubMed Central

Farris, Samantha G.; Davis, Michelle L.; Rosenfield, David; Kauffman, Brooke Y.; Baird, Scarlett O.; Powers, Mark B.; Otto, Michael W.; Marcus, Bess H.; Church, Timothy S.; Smits, Jasper A. J.; Zvolensky, Michael J.

2016-01-01

There is little known about factors that contribute to the comorbidity of cigarette smoking and obesity. The current study sought to test whether exercise self-efficacy moderated the relation between anxiety sensitivity (fear of internal sensations) and BMI and exercise tolerance among cigarette smokers. Smokers (n = 72; 50% female; Mcpd = 19.3, SD = 10.65) were recruited to participate in a smoking cessation treatment trial. During medical screen, we measured weight, height, and exercise tolerance (functional capacity) employing a standardized maximal exercise testing protocol. After adjusting for participant sex and cigarettes per day, exercise self-efficacy moderated the association between anxiety sensitivity and BMI, such that the positive association between anxiety sensitivity and BMI was significantly stronger when exercise self-efficacy was low. The same pattern of results emerged for exercise tolerance. Exercise self-efficacy moderated the association between anxiety sensitivity and exercise tolerance, such that the negative association between anxiety sensitivity and exercise tolerance was significantly stronger when exercise self-efficacy was low. Among smokers, anxiety sensitivity may be a risk variable that, directly and indirectly in the context of low self-efficacy for exercise, causes or maintains higher body weight and lower exercise tolerance. PMID:27725844

Exercise Self-Efficacy Moderates the Relation between Anxiety Sensitivity and Body Mass Index and Exercise Tolerance in Treatment-Seeking Smokers.

PubMed

Farris, Samantha G; Davis, Michelle L; Rosenfield, David; Kauffman, Brooke Y; Baird, Scarlett O; Powers, Mark B; Otto, Michael W; Marcus, Bess H; Church, Timothy S; Smits, Jasper A J; Zvolensky, Michael J

2016-03-01

There is little known about factors that contribute to the comorbidity of cigarette smoking and obesity. The current study sought to test whether exercise self-efficacy moderated the relation between anxiety sensitivity (fear of internal sensations) and BMI and exercise tolerance among cigarette smokers. Smokers ( n = 72; 50% female; M cpd = 19.3, SD = 10.65) were recruited to participate in a smoking cessation treatment trial. During medical screen, we measured weight, height, and exercise tolerance (functional capacity) employing a standardized maximal exercise testing protocol. After adjusting for participant sex and cigarettes per day, exercise self-efficacy moderated the association between anxiety sensitivity and BMI, such that the positive association between anxiety sensitivity and BMI was significantly stronger when exercise self-efficacy was low. The same pattern of results emerged for exercise tolerance. Exercise self-efficacy moderated the association between anxiety sensitivity and exercise tolerance, such that the negative association between anxiety sensitivity and exercise tolerance was significantly stronger when exercise self-efficacy was low. Among smokers, anxiety sensitivity may be a risk variable that, directly and indirectly in the context of low self-efficacy for exercise, causes or maintains higher body weight and lower exercise tolerance.

WHOLE-BODY VIBRATION EXERCISE IS WELL TOLERATED IN PATIENTS WITH DUCHENNE MUSCULAR DYSTROPHY: A SYSTEMATIC REVIEW.

PubMed

Moreira-Marconi, Eloá; Sá-Caputo, Danubia C; Dionello, Carla F; Guedes-Aguiar, Eliane O; Sousa-Gonçalves, Cintia R; Morel, Danielle S; Paineiras-Domingos, Laisa L; Souza, Patricia L; Kütter, Cristiane R; Costa-Cavalcanti, Rebeca G; Costa, Glenda; Paiva, Patricia C; Figueiredo, Claudia; Brandão-Sobrinho-Neto, Samuel; Stark, Christina; Unger, Marianne; Bernardo-Filho, Mario

2017-01-01

Duchenne muscular dystrophy (DMD) is caused by a defective gene located on the X-chromosome, responsible for the production of the dystrophin protein. Complications in the musculoskeletal system have been previously described in DMD patients. Whole body vibration exercise (WBVE) is a treatment that improves musculoskeletal function in movement disorders. The aim of this study was to review the effects of WBVE on functional mobility, bone and muscle in DMD patients. Four databases were searched. Three eligible studies were found; all three conclude the management of DMD patients with WBV was clinically well tolerated. The studies used a side-alternating WBV system, frequencies 7 - 24 Hz; and amplitudes 2 - 4 mm. A work indicates that a temporary increase in creatine kinase in DMD during the first days of WBV was observed, but other authors did not find changes. No significant changes in bone mass, muscle strength or bone markers. Some patients reported subjective functional improvement during training. Interpretation. It is concluded that WBV seems to be a feasible and well tolerated exercise modality in DMD patients.

Transient Receptor Potential Vanilloid 2 Regulates Myocardial Response to Exercise

PubMed Central

Naticchioni, Mindi; Karani, Rajiv; Smith, Margaret A.; Onusko, Evan; Robbins, Nathan; Jiang, Min; Radzyukevich, Tatiana; Fulford, Logan; Gao, Xu; Apel, Ryan; Heiny, Judith; Rubinstein, Jack; Koch, Sheryl E.

2015-01-01

The myocardial response to exercise is an adaptive mechanism that permits the heart to maintain cardiac output via improved cardiac function and development of hypertrophy. There are many overlapping mechanisms via which this occurs with calcium handling being a crucial component of this process. Our laboratory has previously found that the stretch sensitive TRPV2 channels are active regulators of calcium handling and cardiac function under baseline conditions based on our observations that TRPV2-KO mice have impaired cardiac function at baseline. The focus of this study was to determine the cardiac function of TRPV2-KO mice under exercise conditions. We measured skeletal muscle at baseline in WT and TRPV2-KO mice and subjected them to various exercise protocols and measured the cardiac response using echocardiography and molecular markers. Our results demonstrate that the TRPV2-KO mouse did not tolerate forced exercise although they became increasingly exercise tolerant with voluntary exercise. This occurs as the cardiac function deteriorates further with exercise. Thus, our conclusion is that TRPV2-KO mice have impaired cardiac functional response to exercise. PMID:26356305

Comparison of Flow and Volume Incentive Spirometry on Pulmonary Function and Exercise Tolerance in Open Abdominal Surgery: A Randomized Clinical Trial.

PubMed

Kumar, Amaravadi Sampath; Alaparthi, Gopala Krishna; Augustine, Alfred Joseph; Pazhyaottayil, Zulfeequer Chundaanveetil; Ramakrishna, Anand; Krishnakumar, Shyam Krishnan

2016-01-01

Surgical procedures in abdominal area lead to changes in pulmonary function, respiratory mechanics and impaired physical capacity leading to postoperative pulmonary complications, which can affect up to 80% of upper abdominal surgery. To evaluate the effects of flow and volume incentive spirometry on pulmonary function and exercise tolerance in patients undergoing open abdominal surgery. A randomized clinical trial was conducted in a hospital of Mangalore city in Southern India. Thirty-seven males and thirteen females who were undergoing abdominal surgeries were included and allocated into flow and volume incentive spirometry groups by block randomization. All subjects underwent evaluations of pulmonary function with measurement of Forced Vital Capacity (FVC), Forced Expiratory Volume in the first second (FEV1), Peak Expiratory Flow (PEF). Preoperative and postoperative measurements were taken up to day 5 for both groups. Exercise tolerance measured by Six- Minute Walk Test during preoperative period and measured again at the time of discharge for both groups. Pulmonary function was analysed by post-hoc analysis and carried out using Bonferroni's 't'-test. Exercise tolerance was analysed by Paired 'T'-test. Pulmonary function (FVC, FEV1, and PEFR) was found to be significantly decreased in 1(st), 2(nd) and 3(rd) postoperative day when compared with preoperative day. On 4(th) and 5(th) postoperative day the pulmonary function (FVC, FEV1, and PEFR) was found to be better preserved in both flow and volume incentive spirometry groups. The Six-Minute Walk Test showed a statistically significant improvement in pulmonary function on the day of discharge than in the preoperative period. In terms of distance covered, the volume- incentive spirometry group showed a greater statistically significant improvement from the preoperative period to the time of discharge than was exhibited by the flow incentive spirometry group. Flow and volume incentive spirometry can be safely recommended to patients undergoing open abdominal surgery as there have been no adverse events recorded. Also, these led to a demonstrable improvement in pulmonary function and exercise tolerance.

Comparison of Flow and Volume Incentive Spirometry on Pulmonary Function and Exercise Tolerance in Open Abdominal Surgery: A Randomized Clinical Trial

PubMed Central

Kumar, Amaravadi Sampath; Augustine, Alfred Joseph; Pazhyaottayil, Zulfeequer Chundaanveetil; Ramakrishna, Anand; Krishnakumar, Shyam Krishnan

2016-01-01

Introduction Surgical procedures in abdominal area lead to changes in pulmonary function, respiratory mechanics and impaired physical capacity leading to postoperative pulmonary complications, which can affect up to 80% of upper abdominal surgery. Aim To evaluate the effects of flow and volume incentive spirometry on pulmonary function and exercise tolerance in patients undergoing open abdominal surgery. Materials and Methods A randomized clinical trial was conducted in a hospital of Mangalore city in Southern India. Thirty-seven males and thirteen females who were undergoing abdominal surgeries were included and allocated into flow and volume incentive spirometry groups by block randomization. All subjects underwent evaluations of pulmonary function with measurement of Forced Vital Capacity (FVC), Forced Expiratory Volume in the first second (FEV1), Peak Expiratory Flow (PEF). Preoperative and postoperative measurements were taken up to day 5 for both groups. Exercise tolerance measured by Six- Minute Walk Test during preoperative period and measured again at the time of discharge for both groups. Pulmonary function was analysed by post-hoc analysis and carried out using Bonferroni’s ‘t’-test. Exercise tolerance was analysed by Paired ‘T’-test. Results Pulmonary function (FVC, FEV1, and PEFR) was found to be significantly decreased in 1st, 2nd and 3rd postoperative day when compared with preoperative day. On 4th and 5th postoperative day the pulmonary function (FVC, FEV1, and PEFR) was found to be better preserved in both flow and volume incentive spirometry groups. The Six-Minute Walk Test showed a statistically significant improvement in pulmonary function on the day of discharge than in the preoperative period. In terms of distance covered, the volume- incentive spirometry group showed a greater statistically significant improvement from the preoperative period to the time of discharge than was exhibited by the flow incentive spirometry group. Conclusion Flow and volume incentive spirometry can be safely recommended to patients undergoing open abdominal surgery as there have been no adverse events recorded. Also, these led to a demonstrable improvement in pulmonary function and exercise tolerance. PMID:26894090

Ergogenic effects of beetroot juice supplementation during severe-intensity exercise in obese adolescents.

PubMed

Rasica, Letizia; Porcelli, Simone; Marzorati, Mauro; Salvadego, Desy; Vezzoli, Alessandra; Agosti, Fiorenza; De Col, Alessandra; Tringali, Gabriella; Jones, Andrew M; Sartorio, Alessandro; Grassi, Bruno

2018-04-25

Previous studies showed a higher O 2 cost of exercise, and therefore a reduced exercise tolerance, in obese patients during constant work rate (CWR) exercise compared to healthy subjects. Among the ergogenic effects of dietary nitrate (NO 3 -) supplementation in sedentary healthy subjects, a reduced O 2 cost and enhanced exercise tolerance have often been demonstrated. The aim of this study was to evaluate the effects of beetroot juice supplementation, rich in NO 3 -, on physiological variables associated with exercise tolerance in obese adolescents. In a double-blind, randomized, crossover study, ten obese adolescents (8F, 2M; age=16{plus minus}1 yr; BMI=35.2{plus minus}5.0 kg.m -2 ) were tested after 6 days of supplementation with beetroot juice (5 mmol NO 3 - per day) (BR) or placebo (PLA). Following each supplementation period, patients carried out two repetitions of 6-min moderate-intensity CWR exercise and one severe-intensity CWR exercise until exhaustion. Plasma NO 3 - concentration was significantly higher in BR vs. PLA (108{plus minus}37 vs. 15{plus minus}5 μM, P<0.0001). The O 2 cost of moderate-intensity exercise was not different in BR vs. PLA (13.3{plus minus}1.7 vs. 12.9{plus minus}1.1 mL.min -1 .W -1 , P=0.517). During severe-intensity exercise, signs of a reduced amplitude of the O 2 uptake slow component were observed in BR, in association with a significantly longer time to exhaustion (561{plus minus}198 s in BR vs. 457{plus minus}101 s in PLA, P=0.0143). In obese adolescents, short-term dietary NO 3 - supplementation is effective in improving exercise tolerance during severe-intensity exercise. This may prove to be useful in contrasting early fatigue and reduced physical activity in this at-risk population.

In-Home Pulmonary Telerehabilitation for Patients with Chronic Obstructive Pulmonary Disease: A Pre-experimental Study on Effectiveness, Satisfaction, and Adherence.

PubMed

Marquis, Nicole; Larivée, Pierre; Saey, Didier; Dubois, Marie-France; Tousignant, Michel

2015-11-01

Pulmonary rehabilitation (PR) has proven effective in improving exercise tolerance and quality of life in patients with chronic obstructive pulmonary disease (COPD). In Canada, however, there are insufficient rehabilitation services. New strategies such as telerehabilitation must be deployed to increase accessibility. This study aims to investigate the effect of telerehabilitation on exercise tolerance and quality of life and to document patient satisfaction and adherence. Twenty-six patients with moderate to very severe COPD participated in this pre-/postintervention study. They received 15 in-home teletreatment sessions over 8 weeks via videoconference from a service center to their home. Education was provided via self-learning health capsules. Assessments were carried out twice before (T0 and T1; 8 weeks apart) and immediately after the intervention (T2). Primary outcome measures were changes in exercise tolerance (6-min walk test [6MWT] and cycle endurance test [CET]) and quality of life (Chronic Respiratory Questionnaire [CRQ]). There were significant improvements between pre- and postintervention (T2-T1) on the 6MWT (32 m; p<0.001), CET (41 s; p=0.005), and three of four CRQ domains (dyspnea [p<0.001], fatigue [p=0.002], and emotion [p=0.002]). Improvements in the CET and fatigue during the 8-week intervention period were greater than changes over 8 weeks of maturation (T1-T0) (p=0.004 and 0.02, respectively). Participants' satisfaction and adherence rate with telerehabilitation were very high. Using telehealth technology to deliver in-home PR is a feasible and practical solution for patients with moderate to very severe COPD. The telerehabilitation program was associated with beneficial effects on exercise tolerance and quality of life and was well received by users.

Six-minute stepper test: a valid clinical exercise tolerance test for COPD patients

PubMed Central

Grosbois, JM; Riquier, C; Chehere, B; Coquart, J; Béhal, H; Bart, F; Wallaert, B; Chenivesse, C

2016-01-01

Introduction Exercise tolerance testing is an integral part of the pulmonary rehabilitation (PR) management of patients with chronic obstructive pulmonary disease (COPD). The 6-minute stepper test (6MST) is a new, well-tolerated, reproducible exercise test, which can be performed without any spatial constraints. Objective The aim of this study was to compare the results of the 6MST to those obtained during a 6-minute walk test (6MWT) and cardiopulmonary exercise testing (CPET) in a cohort of COPD patients. Methods Ninety-one COPD patients managed by outpatient PR and assessed by 6MST, 6MWT, and CPET were retrospectively included in this study. Correlations between the number of steps on the 6MST, the distance covered on the 6MWT, oxygen consumption, and power at the ventilatory threshold and at maximum effort during CPET were analyzed before starting PR, and the improvement on the 6MST and 6MWT was compared after PR. Results The number of steps on the 6MST was significantly correlated with the distance covered on the 6MWT (r=0.56; P<0.0001), the power at maximum effort (r=0.46; P<0.0001), and oxygen consumption at maximum effort (r=0.39; P<0.005). Performances on the 6MST and 6MWT were significantly improved after PR (570 vs 488 steps, P=0.001 and 448 vs 406 m, respectively; P<0.0001). Improvements of the 6MST and 6MWT after PR were significantly correlated (r=0.34; P=0.03). Conclusion The results of this study show that the 6MST is a valid test to evaluate exercise tolerance in COPD patients. The use of this test in clinical practice appears to be particularly relevant for the assessment of patients managed by home PR. PMID:27099483

Application of acute maximal exercise to protect orthostatic tolerance after simulated microgravity

NASA Technical Reports Server (NTRS)

Engelke, K. A.; Doerr, D. F.; Crandall, C. G.; Convertino, V. A.

1996-01-01

We tested the hypothesis that one bout of maximal exercise performed at the conclusion of prolonged simulated microgravity would improve blood pressure stability during an orthostatic challenge. Heart rate (HR), mean arterial blood pressure (MAP), norepinephrine (NE), epinephrine (E), arginine vasopressin (AVP), plasma renin activity (PRA), atrial natriuretic peptide (ANP), cardiac output (Q), forearm vascular resistance (FVR), and changes in leg volume were measured during lower body negative pressure (LBNP) to presyncope in seven subjects immediately prior to reambulation from 16 days of 6 degrees head-down tilt (HDT) under two experimental conditions: 1) after maximal supine cycle ergometry performed 24 h before returning to the upright posture (exercise) and 2) without exercise (control). After HDT, the reduction of LBNP tolerance time from pre-HDT levels was greater (P = 0.041) in the control condition (-2.0 +/- 0.2 min) compared with the exercise condition (-0.4 +/- 0.2 min). At presyncope after HDT, FVR and NE were higher (P < 0.05) after exercise compared with control, whereas MAP, HR, E, AVP, PRA, ANP, and leg volume were similar in both conditions. Plasma volume (PV) and carotid-cardiac baroreflex sensitivity were reduced after control HDT, but were restored by the exercise treatment. Maintenance of orthostatic tolerance by application of acute intense exercise after 16 days of simulated microgravity was associated with greater circulating levels of NE, vasoconstriction, Q, baroreflex sensitivity, and PV.

Benefits of interval-training on fatigue and functional capacities in Charcot-Marie-Tooth disease.

PubMed

El Mhandi, Lhassan; Millet, Guillaume Y; Calmels, Paul; Richard, Antoine; Oullion, Roger; Gautheron, Vincent; Féasson, Léonard

2008-05-01

Exercise intolerance and undue fatigue are common complaints in patients with Charcot-Marie-Tooth (CMT) disease. Reduced physical ability is due directly to the disease, but it is also due to physical deconditioning. The aim of this study was to test whether 24 weeks of interval-training exercise (ITE) cycling can significantly improve physiological, neuromuscular, and functional capacities and alleviate fatigue in CMT patients. Eight CMT patients (4 CMT1A and 4 CMT2) participated in ITE for 3 nonconsecutive days per week. Cardiovascular fitness, muscle strength, fatigue resistance, and functional capacities were measured before and after 12 weeks of supervised hospital training and again after another 12 weeks of unsupervised home training. Training was well tolerated. There were significant improvements in cardiorespiratory capacities, isokinetic concentric strength, and functional ability measurements. All patients experienced an improvement in their self-reported visual analogic scale for fatigue and pain during training. However, there was no significant change in their isometric force production and indices of fatigue resistance after training. Although the improvement in exercise tolerance may be due in part to reversal of the deconditioning effect of their related sedentary lifestyle, this clinical trial suggests that ITE can benefit CMT patients especially in their functional performance and subjective perception of pain and fatigue. Moreover, the improvement observed at the end of the first supervised period ITE was maintained after the second unsupervised home period, although there was no further improvement in performance and tolerance.

Nicotinamide mononucleotide (NMN) supplementation ameliorates the impact of maternal obesity in mice: comparison with exercise.

PubMed

Uddin, Golam Mezbah; Youngson, Neil A; Doyle, Bronte M; Sinclair, David A; Morris, Margaret J

2017-11-08

Maternal overnutrition increases the risk of long-term metabolic dysfunction in offspring. Exercise improves metabolism partly by upregulating mitochondrial biogenesis or function, via increased levels of nicotinamide adenine dinucleotide (NAD + ). We have shown that the NAD + precursor, nicotinamide mononucleotide (NMN) can reverse some of the negative consequences of high fat diet (HFD) consumption. To investigate whether NMN can impact developmentally-set metabolic deficits, we compared treadmill exercise and NMN injection in offspring of obese mothers. Five week old lean and obese female C57BL6/J mice were mated with chow fed males. Female offspring weaned onto HFD were given treadmill exercise for 9 weeks, or NMN injection daily for 18 days. Maternal obesity programmed increased adiposity and liver triglycerides, with decreased glucose tolerance, liver NAD + levels and citrate synthase activity in offspring. Both interventions reduced adiposity, and showed a modest improvement in glucose tolerance and improved markers of mitochondrial function. NMN appeared to have stronger effects on liver fat catabolism (Hadh) and synthesis (Fasn) than exercise. The interventions appeared to exert the most global benefit in mice that were most metabolically challenged (HFD-consuming offspring of obese mothers). This work encourages further study to confirm the suitability of NMN for use in reversing metabolic dysfunction linked to programming by maternal obesity.

Inhaled fentanyl citrate improves exercise endurance during high-intensity constant work rate cycle exercise in chronic obstructive pulmonary disease.

PubMed

Jensen, Dennis; Alsuhail, Abdullah; Viola, Raymond; Dudgeon, Deborah J; Webb, Katherine A; O'Donnell, Denis E

2012-04-01

Activity limitation and dyspnea are the dominant symptoms of chronic obstructive pulmonary disease (COPD). Traditionally, efforts to alleviate these symptoms have focused on improving ventilatory mechanics, reducing ventilatory demand, or both of these in combination. Nevertheless, many patients with COPD remain incapacitated by dyspnea and exercise intolerance despite optimal therapy. To determine the effect of single-dose inhalation of nebulized fentanyl citrate (a μ-opioid agonist drug) on exercise tolerance and dyspnea in COPD. In a randomized, double-blind, placebo-controlled, crossover study, 12 stable patients with COPD (mean ± standard error of the mean post-β(2)-agonist forced expiratory volume in one second [FEV(1)] and FEV(1) to forced vital capacity ratio of 69% ± 4% predicted and 49% ± 3%, respectively) received either nebulized fentanyl citrate (50 mcg) or placebo on two separate days. After each treatment, patients performed pulmonary function tests and a symptom-limited constant work rate cycle exercise test at 75% of their maximum incremental work rate. There were no significant postdose differences in spirometric parameters or plethysmographic lung volumes. Neither the intensity nor the unpleasantness of perceived dyspnea was, on average, significantly different at isotime (5.0 ± 0.6 minutes) or at peak exercise after treatment with fentanyl citrate vs. placebo. Compared with placebo, fentanyl citrate was associated with 1) increased exercise endurance time by 1.30 ± 0.43 minutes or 25% ± 8% (P=0.01); 2) small but consistent increases in dynamic inspiratory capacity by ∼0.10 L at isotime and at peak exercise (both P≤0.03); and 3) no concomitant change in ventilatory demand, breathing pattern, pulmonary gas exchange, and/or cardiometabolic function during exercise. The mean rate of increase in dyspnea intensity (1.2 ± 0.3 vs. 2.9 ± 0.8 Borg units/minute, P=0.03) and unpleasantness ratings (0.5 ± 0.2 vs. 2.9 ± 1.3 Borg units/minute, P=0.06) between isotime and peak exercise was less after treatment with fentanyl citrate vs. placebo. Single-dose inhalation of fentanyl citrate was associated with significant and potentially clinically important improvements in exercise tolerance in COPD. These improvements were accompanied by a delay in the onset of intolerable dyspnea during exercise near the limits of tolerance. Copyright © 2012 U.S. Cancer Pain Relief Committee. Published by Elsevier Inc. All rights reserved.

Added prognostic value of ischaemic threshold in radionuclide myocardial perfusion imaging: a common-sense integration of exercise tolerance and ischaemia severity.

PubMed

Marini, Cecilia; Acampa, Wanda; Bauckneht, Matteo; Daniele, Stefania; Capitanio, Selene; Cantoni, Valeria; Fiz, Francesco; Zampella, Emilia; Dib, Bassam; Assante, Roberta; Bruzzi, Paolo; Sambuceti, Gianmario; Cuocolo, Alberto

2015-04-01

Reversible ischaemia at radionuclide myocardial perfusion imaging (MPI) accurately predicts risk of cardiac death and nonfatal myocardial infarction (major adverse cardiac events, MACE). This prognostic penetrance might be empowered by accounting for exercise tolerance as an indirect index of ischaemia severity. The present study aimed to verify this hypothesis integrating imaging assessment of ischaemia severity with exercise maximal rate pressure product (RPP) in a large cohort of patients with suspected or known coronary artery disease (CAD). We analysed 1,502 consecutive patients (1,014 men aged 59 ± 10 years) submitted to exercise stress/rest MPI. To account for exercise tolerance, the summed difference score (SDS) was divided by RPP at tracer injection providing a clinical prognostic index (CPI). Reversible ischaemia was documented in 357 patients (24 %) and was classified by SDS as mild (SDS 2-4) in 180, moderate (SDS 5-7) in 118 and severe (SDS >7) in 59. CPI values of ischaemic patients were clustered into tertiles with lowest and highest values indicating low and high risk, respectively. CPI modified SDS risk prediction in 119/357 (33 %) patients. During a 60-month follow-up, MACE occurred in 68 patients. Kaplan-Meier analysis revealed that CPI significantly improved predictive power for MACE incidence with respect to SDS alone. Multivariate Cox analysis confirmed the additive independent value of CPI-derived information. Integration of ischaemic threshold and ischaemia extension and severity can improve accuracy of exercise MPI in predicting long-term outcome in a large cohort of patients with suspected or known CAD.

Music Attenuated a Decrease in Parasympathetic Nervous System Activity after Exercise.

PubMed

Jia, Tiantian; Ogawa, Yoshiko; Miura, Misa; Ito, Osamu; Kohzuki, Masahiro

2016-01-01

Music and exercise can both affect autonomic nervous system activity. However, the effects of the combination of music and exercise on autonomic activity are poorly understood. Additionally, it remains unknown whether music affects post-exercise orthostatic tolerance. The aim of this study was to evaluate the effects of music on autonomic nervous system activity in orthostatic tolerance after exercise. Twenty-six healthy graduate students participated in four sessions in a random order on four separate days: a sedentary session, a music session, a bicycling session, and a bicycling with music session. Participants were asked to listen to their favorite music and to exercise on a cycle ergometer. We evaluated autonomic nervous system activity before and after each session using frequency analysis of heart rate variability. High frequency power, an index of parasympathetic nervous system activity, was significantly increased in the music session. Heart rate was increased, and high frequency power was decreased, in the bicycling session. There was no significant difference in high frequency power before and after the bicycling with music session, although heart rate was significantly increased. Additionally, both music and exercise did not significantly affect heart rate, systolic blood pressure or also heart rate variability indices in the orthostatic test. These data suggest that music increased parasympathetic activity and attenuated the exercise-induced decrease in parasympathetic activity without altering the orthostatic tolerance after exercise. Therefore, music may be an effective approach for improving post-exercise parasympathetic reactivation, resulting in a faster recovery and a reduction in cardiac stress after exercise.

Effects of rehydration on +Gz tolerance after 14-days' bed rest.

NASA Technical Reports Server (NTRS)

Greenleaf, J. E.; Van Beaumont, W.; Bernauer, E. M.; Haines, R. F.; Sandler, H.; Staley, R. W.; Young, H. L.; Yusken, J. W.

1973-01-01

Investigation of the magnitude of reduction in human tolerance to centrifugation following 2 weeks of bed rest with moderate daily exercise. The degree of hypovolemia associated with these exposures is assessed, and the possibility to improve or to return to control levels the tolerance to acceleration forces acting in the head-to-foot direction through rehydration prior to acceleration is explored.

I(f) current inhibitor ivabradine in patients with idiopathic dilated cardiomyopathy: Impact on the exercise tolerance and quality of life.

PubMed

Abdel-Salam, Zainab; Rayan, Mona; Saleh, Ayman; Abdel-Barr, Mohamed G; Hussain, Mohamed; Nammas, Wail

2015-01-01

Evidence supported a beneficial effect of ivabradine on clinical outcome of patients with systolic heart failure, and a sinus heart rate (HR) ≥ 70 bpm. We explored the effect of ivabradine, vs. placebo, added to evidence-based treatment on exercise tolerance and quality of life in patients with idiopathic dilated cardiomyopathy. We enrolled 43 consecutive patients with dilated cardiomyopathy of no apparent cause, a left ventricular ejection fraction (LVEF) < 40%, New York Heart Association class ≥ II, sinus HR ≥ 70 bpm, and background evidence-based anti-failure medications. Ischemic heart disease was ruled out. Patients were randomized (1:1) to receive ivabradine or placebo. Ivabradine was titrated up gradually till 7.5 mg twice daily, or a HR < 60 bpm, and continued for 3 months. Symptom-limited exercise tolerance test was performed, and quality of life was assessed by the Minnesota Living With Heart Failure Questionnaire at 0, and 3 months. Forty-three patients were randomized to ivabradine (n = 20), or placebo (n = 23). Mean age was 50.8 ± 14.5 years (53.5% males). Mean HR was 85 ± 12 bpm, and mean LVEF was 32 ± 6%. Mean dose of carvedilol was 31.2% of the target dose. Baseline HR, blood pressure, exercise tolerance, Minnesota questionnaire score, and left ventricular systolic function were comparable between the two groups (p > 0.05 for all). At 3 months, mean dose of ivabradine was 6.8 mg bid. Ivabradine-treated patients had a lower HR, and improved left ventricular dimensions and systolic function, versus placebo-treated ones (p < 0.05 for all). HR dropped by a mean of 14 bpm in the ivabradine group, corrected for placebo. Both exercise tolerance, and Minnesota questionnaire score were better in the ivabradine group (p < 0.05 both). Ivabradine was well-tolerated. In symptomatic patients with idiopathic dilated cardiomyopathy, the addition of ivabradine, vs. placebo, to evidence-based treatment, reduced HR, and improved functional capacity, at short-term follow-up.

Acceptance and commitment therapy improves exercise tolerance in sedentary women.

PubMed

Ivanova, Elena; Jensen, Dennis; Cassoff, Jamie; Gu, Fei; Knäuper, Bärbel

2015-06-01

To test the efficacy of an acute intervention derived from acceptance and commitment therapy (ACT) for increasing high-intensity constant work rate (CWR) cycle exercise tolerance in a group of low-active women age 18-45 yr. The secondary goals were to examine whether ACT would reduce perceived effort and improve in-task affect during exercise and increase postexercise enjoyment. In a randomized controlled trial, 39 women were randomized to either the experimental (using ACT-based cognitive techniques and listening to music during the CWR exercise tests) or a control group (listening to music during the CWR exercise tests). Before (CWR-1) and after the intervention (CWR-2), participants completed a CWR cycle exercise test at 80% of maximal incremental work rate (Wmax) until volitional exhaustion. On average, ACT (n = 18) and control (n = 21) groups were matched for age, body mass index, weekly leisure activity scores, and Wmax (all P > 0.05). Exercise tolerance time (ETT) increased by 15% from CWR-1 to CWR-2 for the ACT group (392.05 ± 146.4 vs 459.39 ± 209.3 s; mean ± SD) and decreased by 8% (384.71 ± 120.1 vs 353.86 ± 127.9 s) for the control group (P = 0.008). RPE were lower (e.g., by 1.5 Borg 6-20 scale units at 55% of ETT, P ≤ 0.01) during CWR-2 in the ACT versus that in the control group. By contrast, ACT had no effect on in-task affect. Exercise enjoyment was higher after CWR-2 in the ACT group versus that in the control group (P < 0.001). An acute ACT intervention increased high-intensity ETT and postexercise enjoyment and reduced perceived effort in low-active women. Further investigations of ACT as an effective intervention for enhancing the established health benefits of high-intensity exercise need to be provided.

Effects of Nordic walking training on exercise capacity and fitness in men participating in early, short-term inpatient cardiac rehabilitation after an acute coronary syndrome--a controlled trial.

PubMed

Kocur, Piotr; Deskur-Smielecka, Ewa; Wilk, Malgorzata; Dylewicz, Piotr

2009-11-01

To investigate the effects of Nordic Walking training supplemental to a standard, early rehabilitation programme on exercise capacity and physical fitness in men after an acute coronary syndrome. A controlled trial. Cardiac rehabilitation service of a provincial hospital. Eighty men 2-3 weeks after an acute coronary syndrome, with good exercise tolerance. Three-week, inpatient cardiac rehabilitation programme (control group) supplemented with Nordic Walking (Nordic Walking group), or with traditional walking training (walking training group). Exercise capacity was assessed as peak energy cost (in metabolic equivalents) in symptom-limited treadmill exercise test, and physical fitness with the Fullerton Functional Fitness Test. Exercise capacity after the rehabilitation programme was higher in the Nordic Walking group than in the control group (10.8 +/- 1.8 versus 9.2 +/- 2.2 metabolic equivalents, P =0.025). The improvement in exercise capacity in the Nordic Walking group was higher than in the control group (1.8 +/- 1.5 versus 0.7 +/- 1.4 metabolic equivalents, P =0.002). In contrast to the control group, the results of all components of the Fullerton test improved in the Nordic Walking and walking training groups. After the programme, lower body endurance, and dynamic balance were significantly better in the Nordic Walking group in comparison with the walking training and control groups, and upper body endurance was significantly better in the Nordic Walking and walking training groups than in the control group. Nordic Walking may improve exercise capacity, lower body endurance and coordination of movements in patients with good exercise tolerance participating in early, short-term rehabilitation after an acute coronary syndrome.

PoleStriding exercise and vitamin E for management of peripheral vascular disease.

PubMed

Collins, Eileen G; Edwin Langbein, W; Orebaugh, Cynthia; Bammert, Christine; Hanson, Karla; Reda, Domenic; Edwards, Lonnie C; Littooy, Fred N

2003-03-01

The purpose of this investigation was to evaluate the efficacy of PoleStriding exercise (a form of walking that uses muscles of the upper and lower body in a continuous movement similar to cross-country skiing) and vitamin E (alpha-tocopherol) to improve walking ability and perceived quality of life (QOL) of patients with claudication pain secondary to peripheral arterial disease (PAD). Fifty-two subjects were randomized into four groups: PoleStriding with vitamin E (N = 13), PoleStriding with placebo (N= 14), vitamin E without exercise (N= 13), and placebo without exercise (N = 12). The dose of vitamin E was 400 IU daily. Only the PoleStriding with vitamin E and PoleStriding with placebo groups received PoleStriding instruction and training. Assignment to vitamin E or placebo was double blind. Subjects trained three times weekly for 30-45 min (rest time excluded). Individuals in vitamin E and placebo groups came to the laboratory biweekly for ankle blood-pressure measurements. Results of this randomized clinical trial provide strong evidence that PoleStriding significantly (P< 0.001) improved exercise tolerance on the constant work-rate and incremental treadmill tests. Ratings of perceived claudication pain were significantly less after the PoleStriding training program (P= 0.02). In contrast, vitamin E did not have a statistically significant effect on the subjects' ratings of perceived leg pain (P= 0.35) or treadmill walking duration ( P= 0.36). Perceived distance and walking speed (Walking Impairment Questionnaire) and perceived physical function (Rand Short Form-36) improved in the PoleStriding trained group only (P< 0.001, 0.022 and 0.003, respectively). PoleStriding effectively improved the exercise tolerance and perceived QOL of patients with PAD. Little additional benefit to exercise capacity was realized from vitamin E supplementation.

WHOLE-BODY VIBRATION EXERCISE IS WELL TOLERATED IN PATIENTS WITH DUCHENNE MUSCULAR DYSTROPHY: A SYSTEMATIC REVIEW

PubMed Central

Moreira-Marconi, Eloá; Sá-Caputo, Danubia C; Dionello, Carla F; Guedes-Aguiar, Eliane O; Sousa-Gonçalves, Cintia R; Morel, Danielle S; Paineiras-Domingos, Laisa L; Souza, Patricia L; Kütter, Cristiane R; Costa-Cavalcanti, Rebeca G; Costa, Glenda; Paiva, Patricia C; Figueiredo, Claudia; Brandão-Sobrinho-Neto, Samuel; Stark, Christina; Unger, Marianne; Bernardo-Filho, Mario

2017-01-01

Background: Duchenne muscular dystrophy (DMD) is caused by a defective gene located on the X-chromosome, responsible for the production of the dystrophin protein. Complications in the musculoskeletal system have been previously described in DMD patients. Whole body vibration exercise (WBVE) is a treatment that improves musculoskeletal function in movement disorders. The aim of this study was to review the effects of WBVE on functional mobility, bone and muscle in DMD patients. Materials and Methods: Four databases were searched. Three eligible studies were found; all three conclude the management of DMD patients with WBV was clinically well tolerated. The studies used a side-alternating WBV system, frequencies 7 - 24 Hz; and amplitudes 2 - 4 mm. Results: A work indicates that a temporary increase in creatine kinase in DMD during the first days of WBV was observed, but other authors did not find changes. No significant changes in bone mass, muscle strength or bone markers. Some patients reported subjective functional improvement during training. Interpretation: Conclusion: It is concluded that WBV seems to be a feasible and well tolerated exercise modality in DMD patients. PMID:28740938

Whole body vibration exercise improves body balance and walking velocity in postmenopausal osteoporotic women treated with alendronate: Galileo and Alendronate Intervention Trail (GAIT).

PubMed

Iwamoto, J; Sato, Y; Takeda, T; Matsumoto, H

2012-09-01

A randomized controlled trial was conducted to determine the effect of 6 months of whole body vibration (WBV) exercise on physical function in postmenopausal osteoporotic women treated with alendronate. Fifty-two ambulatory postmenopausal women with osteoporosis (mean age: 74.2 years, range: 51-91 years) were randomly divided into two groups: an exercise group and a control group. A four-minute WBV exercise was performed two days per week only in the exercise group. No exercise was performed in the control group. All the women were treated with alendronate. After 6 months of the WBV exercise, the indices for flexibility, body balance, and walking velocity were significantly improved in the exercise group compared with the control group. The exercise was safe and well tolerated. The reductions in serum alkaline phosphatase and urinary cross-linked N-terminal telopeptides of type I collagen during the 6-month period were comparable between the two groups. The present study showed the benefit and safety of WBV exercise for improving physical function in postmenopausal osteoporotic women treated with alendronate.

Aerobic Exercise As a Potential Way to Improve Self-Control after Ego-Depletion in Healthy Female College Students.

PubMed

Zou, Zhiling; Liu, Yang; Xie, Jing; Huang, Xiting

2016-01-01

To test whether aerobic exercise can help build self-control stamina in healthy female young adults. Stamina in this context is defined as the capability to endure ego depletion, which can be measured with a self-control task following another activity also requiring self-control. Forty-five healthy undergraduate women were randomized to either an experimental group or control group. Participants in the experimental group were required to run in their campus running field for 30 min for a period of 5 weeks. Individuals in the control group were required to do diary entries regarding self-control in their daily lives, also for a period of 5 weeks. Before and after the 5-week intervention, participants completed a pain threshold test, a color word Stroop task and the following Cold Pressor Task (CPT) (with and without a distraction component). There was significant decrease of pain tolerance in session 2 relative to session 1 in the control group, but no such decline was found in the experimental group (though the improvement of pain tolerance was not significant), possibly suggesting successful self-control against this kind of decline. Five weeks of aerobic exercise increased self-control after ego depletion in terms of pain tolerance. These findings suggest that aerobic exercise may serve as a potential effective intervention for enhancing self-control in a college female population.

Influence of Very High Breathing Resistance on Exercise Tolerance, Part 1 - Dry Exercise

DTIC Science & Technology

2016-01-01

Influence of Very High Breathing Resistance on Exercise Tolerance, Part 1 – Dry Exercise Authors...Tolerance, Part 1 – Dry Exercise 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Warkander D...exercise (60% of peak O2 consumption) on a cycle ergometer on dry land at sea level. R was such that the work of breathing per volume (volume-averaged

The connection between chronic obstructive pulmonary disease symptoms and hyperinflation and its impact on exercise and function.

PubMed

Cooper, Christopher B

2006-10-01

Forced expiratory volume in 1 second (FEV1) has served as an important diagnostic measurement of chronic obstructive pulmonary disease (COPD) but has not been found to correlate with patient-centered outcomes such as exercise tolerance, dyspnea, or health-related quality of life. It has not helped us understand why some patients with severe FEV1 impairment have better exercise tolerance compared with others with similar FEV1 values. Hyperinflation, or air trapping caused by expiratory flow limitation, causes operational lung volumes to increase and even approach the total lung capacity (TLC) during exercise. Some study findings suggest that a dyspnea limit is reached when the end-inspiratory lung volume encroaches within approximately 500 mL of TLC. The resulting limitation in daily physical activity establishes a cycle of decline that includes physical deconditioning (elevated blood lactic acid levels at lower levels of exercise) and worsening dyspnea. Hyperinflation is reduced by long-acting bronchodilators that reduce airways resistance. The deflation of the lungs, in turn, results in an increased inspiratory capacity. For example, the once-daily anticholinergic bronchodilator tiotropium increases inspiratory capacity, 6-minute walk distance, and cycle exercise endurance time, and it decreases isotime fatigue or dyspnea. Pulmonary rehabilitation and oxygen therapy both reduce ventilatory requirements and improve breathing efficiency, thereby reducing hyperinflation and improving exertional dyspnea. Thus, hyperinflation is directly associated with patient-centered outcomes such as dyspnea and exercise limitation. Furthermore, therapeutic interventions--including pharmacotherapy and lung volume--reduction surgery--that reduce hyperinflation improve these outcomes.

Metabolic and anti-inflammatory benefits of eccentric endurance exercise - a pilot study.

PubMed

Drexel, H; Saely, C H; Langer, P; Loruenser, G; Marte, T; Risch, L; Hoefle, G; Aczel, S

2008-04-01

Eccentric endurance exercise (e.g. hiking downwards) is less strenuous than concentric exercise (e.g. hiking upwards) but its potential to reduce cardiovascular risk is unknown. We randomly allocated 45 healthy sedentary individuals (16 men and 29 women, mean age 48 years) to one of two groups, one beginning with two months of hiking upwards, the other with two months of hiking downwards the same route, with a crossover for a further two months. For the opposite way, a cable car was used where compliance was recorded electronically. The difference in altitude was 540 metres; the distance was covered three to five times a week. Fasting and postprandial metabolic profiles were obtained at baseline and after the two month periods of eccentric and concentric exercise, respectively. Forty-two of the 45 participants completed the study; the compliance rate was therefore 93%. Compared with baseline, eccentric exercise lowered total cholesterol (by 4.1%; P = 0.026), low-density lipoprotein (LDL) cholesterol (by 8.4%, P = 0.001), Apolipoprotein B/Apolipoprotein A1 ratio (by 10.9%, P < 0.001), homeostasis model assessment of insulin resistance scores (by 26.2%, P = 0.017) and C-reactive protein (by 30.0%; P = 0.007); the magnitude of these changes was comparable to that of concentric exercise. Eccentric exercise improved glucose tolerance (by 6.2%, P = 0.023), whereas concentric exercise improved triglyceride tolerance (by 14.9%, P = 0.022). Eccentric endurance exercise is a promising new exercise modality with favourable metabolic and anti-inflammatory effects and is well applicable to sedentary individuals.

Attenuation of exercise-induced heat shock protein 72 expression blunts improvements in whole-body insulin resistance in rats with type 2 diabetes.

PubMed

Tsuzuki, Takamasa; Kobayashi, Hiroyuki; Yoshihara, Toshinori; Kakigi, Ryo; Ichinoseki-Sekine, Noriko; Naito, Hisashi

2017-03-01

Heat shock proteins (HSPs) play an important role in insulin resistance and improve the cellular stress response via HSP induction by exercise to treat type 2 diabetes. In this study, the effects of exercise-induced HSP72 expression levels on whole-body insulin resistance in type 2 diabetic rats were investigated. Male 25-week-old Otsuka Long-Evans Tokushima Fatty rats were divided into three groups: sedentary (Sed), trained in a thermal-neutral environment (NTr: 25 °C), and trained in a cold environment (CTr: 4 °C). Exercise training was conducted 5 days/week for 10 weeks. Rectal temperature was measured following each bout of exercise. An intraperitoneal glucose tolerance test (IPGTT) was performed after the training sessions. The serum, gastrocnemius muscle, and liver were sampled 48 h after the final exercise session. HSP72 and heat shock cognate protein 73 expression levels were analyzed by Western blot, and serum total cholesterol, triglyceride (TG), and free fatty acid (FFA) levels were measured. NTr animals exhibited significantly higher body temperatures following exercise, whereas, CTr animals did not. Exercise training increased HSP72 levels in the gastrocnemius muscle and liver, whereas, HSP72 expression was significantly lower in the CTr group than that in the NTr group (p < 0.05). Glucose tolerance improved equally in both trained animals; however, insulin levels during the IPGTT were higher in CTr animals than those in NTr animals (p < 0.05). In addition, the TG and FFA levels decreased significantly only in NTr animals compared with those in Sed animals. These results suggest that attenuation of exercise-induced HSP72 expression partially blunts improvement in whole-body insulin resistance and lipid metabolism in type 2 diabetic rats.

Exercise Versus +Gz Acceleration Training

NASA Technical Reports Server (NTRS)

Greenleaf, John E.; Simonson, S. R.; Stocks, J. M.; Evans, J. M.; Knapp, C. F.; Dalton, Bonnie P. (Technical Monitor)

2002-01-01

Decreased working capacity and "orthostatic" intolerance are two major problems for astronauts during and after landing from spaceflight in a return vehicle. The purpose was to test the hypotheses that (1) supine-passive-acceleration training, supine-interval-exercise plus acceleration training, and supine exercise plus acceleration training will improve orthostatic tolerance (OT) in ambulatory men; and that (2) addition of aerobic exercise conditioning will not influence this enhanced OT from that of passive-acceleration training. Seven untrained men (24-38 yr) underwent 3 training regimens (30 min/d x 5d/wk x 3wk on the human-powered centrifuge - HPC): (a) Passive acceleration (alternating +1.0 Gz to 50% Gzmax); (b) Exercise acceleration (alternating 40% - 90% V02max leg cycle exercise plus 50% of HPCmax acceleration); and (c) Combined intermittent exercise-acceleration at 40% to 90% HPCmax. Maximal supine exercise workloads increased (P < 0.05) by 8.3% with Passive, by 12.6% with Exercise, and by 15.4% with Combined; but maximal V02 and HR were unchanged in all groups. Maximal endurance (time to cessation) was unchanged with Passive, but increased (P < 0.05) with Exercise and Combined. Resting pre-tilt HR was elevated by 12.9% (P < 0.05) only after Passive training, suggesting that exercise training attenuated this HR response. All resting pre-tilt blood pressures (SBP, DBP, MAP) were not different pre- vs. post-training. Post-training tilt-tolerance time and HR were increased (P < 0.05) only with Passive training by 37.8% and by 29.1%, respectively. Thus, addition of exercise training attenuated the increased Passive tilt tolerance. Resting (pre-tilt) and post-tilt cardiac R-R interval, stroke volume, end-diastolic volume, and cardiac output were all uniformly reduced (P < 0.05) while peripheral resistance was uniformly increased (P < 0.05) pre-and post-training for the three regimens indicating no effect of any training regimen on those cardiovascular variables. Plasma volume (% delta) was uniformly decreased by 8% to 14% (P < 0.05) at tilt-tolerance pre- vs. post-training for all regimens indicating no effect of these training regimens on the level of vascular fluid shifts.

A single bout of high-intensity interval exercise and work-matched moderate-intensity exercise has minimal effect on glucose tolerance and insulin sensitivity in 7- to 10-year-old boys.

PubMed

Cockcroft, Emma J; Williams, Craig A; Jackman, Sarah R; Bassi, Shikhar; Armstrong, Neil; Barker, Alan R

2018-01-01

The purpose of this study was to assess the acute effect of high-intensity interval exercise (HIIE) and moderate-intensity exercise (MIE) on glucose tolerance, insulin sensitivity and fat oxidation in young boys. Eleven boys (8.8 ± 0.8 y) completed three conditions: 1) HIIE; 2) work-matched MIE; and 3) rest (CON) followed by an oral glucose tolerance test (OGTT) to determine glucose tolerance and insulin sensitivity (Cederholm index). Fat oxidation was measured following the OGTT using indirect calorimetry. There was no effect for condition on plasma [glucose] and [insulin] area under the curve (AUC) responses following the OGTT (P > 0.09). However, there was a "trend" for a condition effect for insulin sensitivity with a small increase after HIIE (P = 0.04, ES = 0.28, 9.7%) and MIE (P = 0.07, ES = 0.21, 6.5%) compared to CON. There was an increase in fat oxidation AUC following HIIE (P = 0.008, ES = 0.79, 38.9%) compared to CON, but with no differences between MIE and CON and HIIE and MIE (P > 0.13). In conclusion, 7- to 10-year-old boys may have limited scope to improve insulin sensitivity and glucose tolerance after a single bout of HIIE and MIE. However, fat oxidation is augmented after HIIE but not MIE.

Peptide Glutamine Supplementation for Tolerance of Intermittent Exercise in Soccer Players

PubMed Central

Favano, Alessandra; Santos-Silva, Paulo Roberto; Nakano, Eduardo Yoshio; Pedrinelli, André; Hernandez, Arnaldo José; Greve, Julia Maria D’Andrea

2008-01-01

OBJECTIVE To investigate whether supplementation of carbohydrate together with peptide glutamine would increase exercise tolerance in soccer players. METHODS Nine male soccer players (mean age: 18.4 ± 1.1 years; body mass: 69.2 ± 4.6 kg; height: 175.5 ± 7.3 cm; and maximum oxygen consumption of 57.7 ± 4.8 ml·kg−1·min−1) were evaluated. All of them underwent a cardiopulmonary exercise test and followed a protocol that simulated the movements of a soccer game in order to evaluate their tolerance to intermittent exercise. By means of a draw, either carbohydrate with peptide glutamine (CARBOGLUT: 50g of maltodextrin + 3.5g of peptide glutamine in 250 ml of water) or carbohydrate alone (CARBO: 50g of maltodextrin in 250 ml of water) was administered in order to investigate the enhancement of the soccer players’ performances. The solution was given thirty minutes before beginning the test, which was performed twice with a one-week interval between tests. RESULTS A great improvement in the time and distance covered was observed when the athletes consumed the CARBOGLUT mixture. Total distance covered was 12750 ± 4037m when using CARBO, and 15571 ± 4184m when using CARBOGLUT (p<0.01); total duration of tolerance was 73 ± 23 min when using CARBO and 88 ± 24 min when using CARBOGLUT (p<0.01). CONCLUSION The CARBOGLUT mixture was more efficient in increasing the distance covered and the length of time for which intermittent exercise was tolerated. CARBOGLUT also reduced feelings of fatigue in the players compared with the use of the CARBO mixture alone. PMID:18297203

Likelihood of myocardial infarction during stroke rehabilitation preceded by cardiovascular screening and an exercise tolerance test: the Locomotor Experience Applied Post-Stroke (LEAPS) trial.

PubMed

Nadeau, Stephen E; Rose, Dorian Kay; Dobkin, Bruce; Wu, Samuel S; Dai, Yufeng E; Schofield, Richard; Duncan, Pamela W

2014-12-01

Coronary artery disease is highly prevalent in patients with stroke, but because revascularization does not improve major clinical outcomes in patients with stable coronary artery disease relative to intensive medical therapy, routine evaluation for this disease is not warranted in stroke patients. However, it might be warranted in patients destined to undergo vigorous physical therapy. The Locomotor Experience Applied Post-Stroke study, a randomized controlled trial of 408 participants that tested the relative efficacy of two rehabilitation techniques on functional walking level, provided the opportunity to address this question. The study aims to test the efficacy of screening for cardiovascular disease and an exercise tolerance test in assuring safety among patients undergoing vigorous rehabilitation for gait impairment. All participants were screened for serious cardiovascular and pulmonary conditions. At six-weeks poststroke, they also completed a cardiovascular screening inventory and underwent an exercise tolerance test involving bicycle ergometry. Participants received 36, 90-min sessions of a prescribed physical therapy (three per week), initiated at either two-months or six-months poststroke. Twenty-nine participants were excluded on the basis of the cardiac screening questionnaire, and 15 failed the exercise tolerance test for cardiovascular reasons. No participant experienced a cardiac event during a treatment session. Two participants experienced myocardial infarctions, but continued in the trial. In three additional participants, myocardial infarctions caused or contributed to death. The combination of a negative cardiac screen and the absence of exercise tolerance test failure appeared to have a high negative predictive value for cardiac events during treatment, despite the likelihood of a high prevalence of coronary artery disease in our population. © 2014 World Stroke Organization.

High-intensity interval training combined with resistance training improves physiological capacities, strength and quality of life in multiple sclerosis patients: a pilot study.

PubMed

Zaenker, Pierre; Favret, Fabrice; Lonsdorfer, Evelyne; Muff, Guillaume; de Seze, Jérôme; Isner-Horobeti, Marie-Eve

2018-02-01

Numerous studies have shown that mild-to-moderate intensity or resistance exercise training improves physical capacities such as, peak oxygen consumption, maximal tolerated power and strength in multiple sclerosis patients. However, few studies have evaluated the effects of high-intensity interval training (HIIT) associated to with resistance training. Only few studies have analyzed difference between men and women before and after combined training. Moreover, the evaluation of exercise between ambulatory multiple sclerosis patients without disability (Expanded Disability Status Score [EDSS] 0-3) and patients with disabilities (EDSS 3.5-5) was not largely published. The main objective of our study was to determine if HIIT combined with resistance training improved aerobic and strength capacities as well as quality of life in multiple sclerosis patients and if gender and disabilities play a role in these changes. This study was an open-label uncontrolled study. The study was performed outside from conventional care facilities and including homebased training. Twenty-six multiple sclerosis patients have completed the program (19 women, 7 men; mean age 44.6±7.9 years, EDSS 2 [0-5]). We conducted a 12-week program of high-intensity interval training combined with resistance training at body weight. Peak oxygen consumption, maximal tolerated power, lactates, isokinetic strength of quadriceps and hamstrings (at 90°/s, 180°/s, and 240°/s) and quality of life were evaluated before and after the program. Peak oxygen consumption and maximum tolerated power improved by 13.5% and 9.4%, respectively. Isokinetic muscle strength increased in both quadriceps and hamstrings at each speed, with a rebalancing of strength between the two legs in quadriceps. Quality of life was also enhanced in three domains. Women showed better improvements than men in V̇O2peak, maximal tolerated power, lactates at the end of test, and heart rate peak, strength in both quadriceps and hamstrings mostly at low speed, and quality of life. The two EDSS groups increased V̇O2peak and strength. Our study has shown that HIIT combined with resistance exercise training induced an improvement in physical capacity and quality of life. Moreover, this study allowed patients, irrespective of their sex or EDSS score, to resume exercise autonomously. The results of the study showed that aerobic training at moderate intensity is not the single type of training tolerated by multiple sclerosis patients. High-intensity interval training is well tolerated too and can be used in clinical rehabilitation with resistance training, in both men and women with and without disabilities.

Comparison of Gait During Treadmill Exercise While Supine in Lower Body Negative Pressure (LBNP), Supine with Bungee Resistance and Upright in Normal Gravity

NASA Technical Reports Server (NTRS)

Boda, Wanda; Hargens, Alan R.; Aratow, Michael; Ballard, Richard E.; Hutchinson, Karen; Murthy, Gita; Campbell, James

1994-01-01

The purpose of this study is to compare footward forces, gait kinematics, and muscle activation patterns (EMG) generated during supine treadmill exercise against LBNP with the same parameters during supine bungee resistance exercise and upright treadmill exercise. We hypothesize that the three conditions will be similar. These results will help validate treadmill exercise during LBNP as a viable technique to simulate gravity during space flight. We are evaluating LBNP as a means to load the musculoskeletal and cardiovascular systems without gravity. Such loading should help prevent physiologic deconditioning during space flight. The best ground-based simulation of LBNP treadmill exercise in microgravity is supine LBNP treadmill exercise on Earth because the supine footward force vector is neither directed nor supplemented by Earth's gravity. Previous results from HR-95 ("Dynamics of footward force and leg intramuscular pressure during exercise against supine LBNP and upright standing in normal gravity") indicate that supine plantar-/dorsiflexion exercise in LBNP at 100 mm Hg produces similar ground reaction forces, musculoskeletal stress, and VO2 to those during upright exercise against Earth's gravity. However, elevations of leg volume and heart rate indicate that cardiovascular stress during 100 mm Hg LBNP exercise exceeds that during 1 g exercise. Therefore, the need arose to reduce the cardiovascular stress of LBNP, while maintaining LBNP-induced reaction forces. To this end, we determined that mild plantar-/dorsiflexion exercise during LBNP significantly improves tolerance to LBNP via musculovenous pumping and sympathoexcitation; more intense exercise such as walking and running may further improve LBNP tolerance. In addition, two methodological advances have permited us to simulate upright 1 g exercise better with supine LBNP exercise. First, a newly-designed waist seal allows decreased levels of LBNP (50-60 mm Hg) to produce a footward force equaling one body weight

Improved training tolerance by supplementation with α-Keto acids in untrained young adults: a randomized, double blind, placebo-controlled trial

PubMed Central

2012-01-01

Background Exercise causes a variety of physiological and metabolic changes that can in turn reduce exercise tolerance. One of the potential mechanisms responsible for fatigue is “exercise-induced hyperammonemia”. Previous studies have shown that supplementation with amino acids can increase training tolerance. The α-keto acids are biochemical analogs of amino acids and can be converted to amino acids through transamination, thus reducing the cellular ammonia level. This double blind, placebo-controlled study was designed to investigate the effects of α-keto acid supplementation (KAS) on training tolerance, training effect, and stress-recovery state. Methods Thirty-three untrained young male adults underwent four weeks of training (5 sessions/week; 30 minutes running at the individual anaerobic threshold followed by 3 x 3 minute sprints/each session). Throughout the 4 weeks of training and one week of recovery, subjects took α-ketoglutarate (AKG group, 0.2 g/kg/d, n = 9), branched-chain keto acids (BCKA group, 0.2 g/kg/d, n = 12) or isocaloric placebo (control group, n = 12) daily. Results The 4th week training volume, maximum power output and muscle torque were higher in the AKG group (175 ± 42 min, 412 ± 49 Watts and 293 ± 58 Newton meters, respectively, P<0.05) and the BCKA group (158 ± 35, 390 ± 29 and 273 ± 47, P<0.05) than in the control group (92 ± 70, 381 ± 67 and 233 ± 43). The general stress and emotional exhaustion as assessed by the rest-stress-questionnaire-sport after the 3rd week of training increased significantly in the control group (P<0.05), but not in the KAS groups. Conclusions Under KAS, subjects could bear a higher training volume and reach a higher power output and peak muscle torque, accompanied by a better stress-recovery-state. Thus, KAS improves exercise tolerance and training effects along with a better stress-recovery state. Whether the improved training tolerance by KAS is associated with effects on ammonia homeostasis requires further observation. PMID:22857787

Relation of N-Terminal Pro-B-Type Natriuretic Peptide and Left Ventricular Diastolic Function to Exercise Tolerance in Patients With Significant Valvular Heart Disease and Normal Left Ventricular Systolic Function.

PubMed

Hwang, Ji-Won; Park, Sung-Ji; Cho, Eun Jeong; Kim, Eun Kyoung; Lee, Ga Yeon; Chang, Sung-A; Choi, Jin-Oh; Lee, Sang-Chol; Park, Seung Woo

2017-06-01

An association between N-terminal prohormone brain natriuretic peptide (NT-proBNP) and exercise tolerance in patients with valvular heart disease (VHD) has been suggested; however, there are few data available regarding this relation. The aim of this study is to evaluate the correlation between exercise tolerance and NT-proBNP in patients with asymptomatic or mildly symptomatic significant VHD and normal left ventricular ejection fraction (LV EF). A total of 96 patients with asymptomatic or mildly symptomatic VHD and normal LV EF (≥50%) underwent cardiopulmonary exercise echocardiography. NT-proBNP levels were determined at baseline and after exercise in 3 hours. Patients were divided in 2 groups based on lower (<26 ml/kg/min, n = 47) or higher (≥26 ml/kg/min, n = 49) peak oxygen consumption (VO 2 ) as a representation of exercise tolerance. In the 2 groups, after adjusting for age and gender, the NT-proBNP level after exercise in 3 hours, left atrial volume index before exercise, right ventricular systolic pressure before exercise, E velocity after exercise, and E/e' ratio after exercise varied significantly. In addition, peak VO 2 was inversely related to NT-proBNP before (r = -0.352, p <0.001) and after exercise (r = -0.351, p <0.001). The NT-proBNP level before exercise was directly related to the left atrial volume index, E/e' ratio, and right ventricular systolic pressure before and after exercise. NT-proBNP after exercise was also directly related to the same parameters. NT-proBNP levels both before and after exercise were higher in the group with lower exercise tolerance. In conclusion, through the correlation among exercise tolerance, NT-proBNP, and parameters of diastolic dysfunction, we demonstrated that diastolic dysfunction and NT-proBNP could predict exercise tolerance in patients with significant VHD and normal LV EF. Copyright © 2017 Elsevier Inc. All rights reserved.

Exercise countermeasures for bed-rest deconditioning

NASA Technical Reports Server (NTRS)

Greenleaf, John (Editor)

1993-01-01

The purpose for this 30-day bed rest study was to investigate the effects of short-term, high intensity isotonic and isokinetic exercise training on maintenance of working capacity (peak oxygen uptake), muscular strength and endurance, and on orthostatic tolerance, posture and gait. Other data were collected on muscle atrophy, bone mineralization and density, endocrine analyses concerning vasoactivity and fluid-electrolyte balance, muscle intermediary metabolism, and on performance and mood of the subjects. It was concluded that: The subjects maintained a relatively stable mood, high morale, and high esprit de corps throughout the study. Performance improved in nearly all tests in almost all the subjects. Isotonic training, as opposed to isokinetic exercise training, was associated more with decreasing levels of psychological tension, concentration, and motivation; and improvement in the quality of sleep. Working capacity (peak oxygen uptake) was maintained during bed rest with isotonic exercise training; it was not maintained with isokinetic or no exercise training. In general, there was no significant decrease in strength or endurance of arm or leg muscles during bed rest, in spite of some reduction in muscle size (atrophy) of some leg muscles. There was no effect of isotonic exercise training on orthostasis, since tilt-table tolerance was reduced similarly in all three groups following bed rest. Bed rest resulted in significant decreases of postural stability and self-selected step length, stride length, and walking velocity, which were not influenced by either exercise training regimen. Most pre-bed rest responses were restored by the fourth day of recovery.

Effects of a 10-week multimodal exercise program on physical and cognitive function of nursing home residents: a psychomotor intervention pilot study.

PubMed

Pereira, Catarina; Rosado, Hugo; Cruz-Ferreira, Ana; Marmeleira, José

2018-05-01

Nursing home institutionalization tends to exacerbate loss of functioning. Examine the feasibility and the effect of a psychomotor intervention-a multimodal exercise program promoting simultaneous cognitive and motor stimulation-on the executive (planning ability and selective attention) and physical function of nursing home residents. Seventeen participants engaged in a 10-week multimodal exercise program and 17 maintained usual activities. Exercise group improved planning ability (25-32%), selective attention (19-67%), and physical function [aerobic endurance, lower body strength, agility, balance, gait, and mobility (19-41%)], corresponding to an effect size ranging from 0.29 (small) to 1.11 (high), p < 0.05. The multimodal exercise program was feasible and well tolerated. The program improved executive and physical functions of the nursing home residents, reverting the usual loss of both cognitive and motor functioning in older adult institutionalized. Multimodal exercise programs may help to maintain or improve nursing home residents' functioning.

The importance of daily physical activity for improved exercise tolerance in heart failure patients with limited access to centre-based cardiac rehabilitation.

PubMed

Sato, Noriaki; Origuchi, Hideki; Yamamoto, Umpei; Takanaga, Yasuhiro; Mohri, Masahiro

2012-09-01

Supervised cardiac rehabilitation provided at dedicated centres ameliorates exercise intolerance in patients with chronic heart failure. To correlate the amount of physical activity outside the hospital with improved exercise tolerance in patients with limited access to centre-based programs. Forty patients (median age 69 years) with stable heart failure due to systolic left ventricular dysfunction participated in cardiac rehabilitation once per week for five months. Using a validated single-axial accelerometer, the number of steps and physical activity-related energy expenditures on nonrehabilitation days were determined. Median (interquartile range) peak oxygen consumption was increased from 14.4 mL/kg/min (range 12.9 mL/kg/min to 17.8 mL/kg/min) to 16.4 mL/kg/min (range 13.9 mL/kg/min to 19.1 mL/kg/min); P<0.0001, in association with a decreased slope of the minute ventilation to carbon dioxide production plot (34.2 [range 31.3 to 38.1] versus 32.7 [range 30.3 to 36.5]; P<0.0001). Changes in peak oxygen consumption were correlated with the daily number of steps (P<0.01) and physical activity-related energy expenditures (P<0.05). Furthermore, these changes were significantly correlated with total exercise time per day and time spent for light (≤3 metabolic equivalents) exercise, but not with time spent for moderate/vigorous (>3 metabolic equivalents) exercise. The number of steps and energy expenditures outside the hospital were correlated with improved exercise capacity. An accelerometer may be useful for guiding home-based cardiac rehabilitation.

International Society of Sports Nutrition position stand: safety and efficacy of creatine supplementation in exercise, sport, and medicine.

PubMed

Kreider, Richard B; Kalman, Douglas S; Antonio, Jose; Ziegenfuss, Tim N; Wildman, Robert; Collins, Rick; Candow, Darren G; Kleiner, Susan M; Almada, Anthony L; Lopez, Hector L

2017-01-01

Creatine is one of the most popular nutritional ergogenic aids for athletes. Studies have consistently shown that creatine supplementation increases intramuscular creatine concentrations which may help explain the observed improvements in high intensity exercise performance leading to greater training adaptations. In addition to athletic and exercise improvement, research has shown that creatine supplementation may enhance post-exercise recovery, injury prevention, thermoregulation, rehabilitation, and concussion and/or spinal cord neuroprotection. Additionally, a number of clinical applications of creatine supplementation have been studied involving neurodegenerative diseases (e.g., muscular dystrophy, Parkinson's, Huntington's disease), diabetes, osteoarthritis, fibromyalgia, aging, brain and heart ischemia, adolescent depression, and pregnancy. These studies provide a large body of evidence that creatine can not only improve exercise performance, but can play a role in preventing and/or reducing the severity of injury, enhancing rehabilitation from injuries, and helping athletes tolerate heavy training loads. Additionally, researchers have identified a number of potentially beneficial clinical uses of creatine supplementation. These studies show that short and long-term supplementation (up to 30 g/day for 5 years) is safe and well-tolerated in healthy individuals and in a number of patient populations ranging from infants to the elderly. Moreover, significant health benefits may be provided by ensuring habitual low dietary creatine ingestion (e.g., 3 g/day) throughout the lifespan. The purpose of this review is to provide an update to the current literature regarding the role and safety of creatine supplementation in exercise, sport, and medicine and to update the position stand of International Society of Sports Nutrition (ISSN).

Aerobic Exercise As a Potential Way to Improve Self-Control after Ego-Depletion in Healthy Female College Students

PubMed Central

Zou, Zhiling; Liu, Yang; Xie, Jing; Huang, Xiting

2016-01-01

Purpose: To test whether aerobic exercise can help build self-control stamina in healthy female young adults. Stamina in this context is defined as the capability to endure ego depletion, which can be measured with a self-control task following another activity also requiring self-control. Methods: Forty-five healthy undergraduate women were randomized to either an experimental group or control group. Participants in the experimental group were required to run in their campus running field for 30 min for a period of 5 weeks. Individuals in the control group were required to do diary entries regarding self-control in their daily lives, also for a period of 5 weeks. Before and after the 5-week intervention, participants completed a pain threshold test, a color word Stroop task and the following Cold Pressor Task (CPT) (with and without a distraction component). Results: There was significant decrease of pain tolerance in session 2 relative to session 1 in the control group, but no such decline was found in the experimental group (though the improvement of pain tolerance was not significant), possibly suggesting successful self-control against this kind of decline. Conclusions: Five weeks of aerobic exercise increased self-control after ego depletion in terms of pain tolerance. These findings suggest that aerobic exercise may serve as a potential effective intervention for enhancing self-control in a college female population. PMID:27148113

Adenoviral beta-adrenergic receptor kinase inhibitor gene transfer improves exercise capacity, cardiac contractility, and systemic inflammation in a model of pressure overload hypertrophy.

PubMed

Gupta, Dipin; Molina, Ezequiel J; Palma, Jon; Gaughan, John P; Long, Walter; Macha, Mahender

2008-10-01

We hypothesized that intracoronary adenoviral-mediated delivery of betaARKct would improve heart failure associated pathophysiologic abnormalities related to exercise capacity, cardiac contractility, systemic inflammation and volume overload. After aortic banding, a cohort of Sprague-Dawley rats was followed by echocardiography. When an absolute decline of 25% in fractional shortening was detected, animals were randomized to intracoronary delivery of Ad.ssARKct (n=14), Ad.beta-Gal (n=13), or followed without any other further intervention (n=18). Assessment of exercise tolerance and hemodynamic profile and measurement of markers of systemic inflammation and volume overload was performed at 7, 14, and 21 days after gene delivery. Data were analyzed using ANOVA. Animals receiving Ad.ssARKct showed improved exercise tolerance compared to Ad.Gal-treated animals at 14 days (507+/-26 s vs. 408+/-19 s, P=0.01) and 21 days (526+/-55 s vs. 323+/-19 s, P<0.001) following injection. Animals receiving Ad.ssARKct demonstrated improved +dP/dtmax (mean+/-SD, 5,581+/-960 mmHg/s vs. 3,134+/-438 mmHg/s, P<0.01) and -dP/dtmax (mean+/-SD, -3,494+/-1,269 mmHg/s vs. -1,925+/-638 mmHg/s, P<0.01) compared to Ad.Gal-treated animals at 7 days. These differences were observed up to 21 days following injection. Serum levels of IL-1, IL-6, and TNF-alpha, as well as ANP were also decreased in animals receiving Ad.betaARKct. Genetic modulation of heart failure using the betaARKct gene was associated with improved exercise capacity and cardiac function as well as amelioration in heart failure-associated profiles of systemic inflammation and volume overload.

Exercise Training and Cardiovascular Health in Cancer Patients.

PubMed

Squires, Ray W; Shultz, Adam M; Herrmann, Joerg

2018-03-10

Cancer patients nearly universally experience a decline in quality of life, with fatigue and reduced exercise tolerance as cardinal reflections. A routine exercise program can improve these signs and symptoms as well as overall outcomes. The review provides an updated overview of the field and its translation to clinical practice. A wealth of clinical studies have documented the safety and benefits of exercise after and during cancer therapy, and pilot and larger-scale studies are currently ongoing to integrate exercise into the treatment program for cancer patients undergoing active therapy (EXACT pilot, OptiTrain, and TITAN study). More recently, efforts have emerged to commence exercise programs before the start of cancer therapy, so-called pre-habilitation. The concept of increasing the cardiovascular reserve beforehand is intuitively attractive. In agreement, preclinical studies support exercise as an effective preventive means before and during cardiotoxic drug exposure. Assuming that a pronounced drop in exercise tolerance will occur during cancer therapy, pre-habilitation can potentially curtail or raise the nadir level of exercise tolerance. Furthermore, such efforts might serve as pre-conditioning efforts in reducing not only the nadir, but even the magnitude of drop in cardiovascular reserve. Initiated beforehand, cancer patients are also more likely to continue these efforts during cancer therapy. Finally, an active exercise routine (≥ 150 min/week moderate intensity or ≥ 75 min/week vigorous intensity or combination) in conjunction with the other six American Heart Association's cardiovascular health metrics (BMI < 25 kg/m 2 , blood pressure < 120/80 mmHg, fasting plasma glucose < 100 mg/dL, total cholesterol < 200 mg/dL, 4-5 component healthy diet, no smoking) reduces not only the cardiovascular but also the cancer disease risk. Exercise can reduce the risks of developing cancer, the detrimental effects of its treatment on the cardiovascular system, and overall morbidity and mortality. Exercise should become an integral part of the care for every cancer patient.

Post-Exercise Carbohydrate-Energy Replacement Attenuates Insulin Sensitivity and Glucose Tolerance the Following Morning in Healthy Adults

PubMed Central

Taylor, Harry L.; Wu, Ching-Lin; Chen, Yung-Chih; Wang, Pin-Ging; Betts, James A.

2018-01-01

The carbohydrate deficit induced by exercise is thought to play a key role in increased post-exercise insulin action. However, the effects of replacing carbohydrate utilized during exercise on postprandial glycaemia and insulin sensitivity are yet to be determined. This study therefore isolated the extent to which the insulin-sensitizing effects of exercise are dependent on the carbohydrate deficit induced by exercise, relative to other exercise-mediated mechanisms. Fourteen healthy adults performed a 90-min run at 70% V˙O2max starting at 1600–1700 h before ingesting either a non-caloric artificially-sweetened placebo solution (CHO-DEFICIT) or a 15% carbohydrate solution (CHO-REPLACE; 221.4 ± 59.3 g maltodextrin) to precisely replace the measured quantity of carbohydrate oxidized during exercise. The alternate treatment was then applied one week later in a randomized, placebo-controlled, and double-blinded crossover design. A standardized low-carbohydrate evening meal was consumed in both trials before overnight recovery ahead of a two-hour oral glucose tolerance test (OGTT) the following morning to assess glycemic and insulinemic responses to feeding. Compared to the CHO-DEFICIT condition, CHO-REPLACE increased the incremental area under the plasma glucose curve by a mean difference of 68 mmol·L−1 (95% CI: 4 to 132 mmol·L−1; p = 0.040) and decreased the Matsuda insulin sensitivity index by a mean difference of −2 au (95% CI: −1 to −3 au; p = 0.001). This is the first study to demonstrate that post-exercise feeding to replaceme the carbohydrate expended during exercise can attenuate glucose tolerance and insulin sensitivity the following morning. The mechanism through which exercise improves insulin sensitivity is therefore (at least in part) dependent on carbohydrate availability and so the day-to-day metabolic health benefits of exercise might be best attained by maintaining a carbohydrate deficit overnight. PMID:29370143

Lack of effect of nitrates on exercise tolerance in patients with mild to moderate heart failure caused by coronary disease already treated with captopril.

PubMed

Wieshammer, S; Hetzel, M; Hetzel, J; Kochs, M; Hombach, V

1993-07-01

To test the hypothesis that the addition of nitrates improves exercise tolerance in patients with heart failure caused by coronary artery disease already treated with an angiotensin converting enzyme inhibitor and diuretics. Randomised, double blind, placebo controlled, 16 week treatment periods. Outpatient clinic at a university hospital. 54 patients with previous myocardial infarction, symptoms of mild to moderate heart failure, left ventricular ejection fraction below 40%, no exercise-induced angina or electrocardiographic signs of ischaemia. Four patients in the nitrate group (n = 24) and one patient of the placebo group (n = 25) were withdrawn from the study. After the patients had been on constant doses of captopril and diuretics for at least 2 weeks, they were randomised to receive a target dose of 40 mg isosorbide dinitrate twice daily or placebo in addition to the continuation of captopril and diuretics. Bicycle exercise tests with measurement of gas exchange were carried out before randomisation and after 1, 6, 12, and 16 weeks of the double blind treatment. The change in peak oxygen uptake from control to week 16 was prospectively defined as the main outcome measure. The increase in peak oxygen uptake from before randomisation tended to be greater in the placebo group (before randomisation 17.4 (3.4) ml/min/kg) than in the nitrate group (before randomisation 17.1 (3.5) ml/min/kg) after 12 weeks (mean increase 1.1 (2.7) v 0.0 (2.7) ml/min/kg, p < 0.12) and 16 weeks (1.7 (3.0) v 0.3 (2.6) ml/min/kg, p < 0.14) of treatment. The addition of nitrates to a baseline treatment consisting of captopril and diuretics did not improve exercise tolerance.

Central dopaminergic neurotransmission plays an important role in thermoregulation and performance during endurance exercise.

PubMed

Zheng, Xinyan; Hasegawa, Hiroshi

2016-10-01

Dopamine (DA) has been widely investigated for its potential role in determining exercise performance. It was originally thought that DA's ergogenic effect was by mediating psychological responses. Recently, some studies have also suggested that DA may regulate physiological responses, such as thermoregulation. Hyperthermia has been demonstrated as an important limiting factor during endurance exercise. DA is prominent in the thermoregulatory centre, and changes in DA concentration have been shown to affect core temperature regulation during exercise. Some studies have proposed that DA or DA/noradrenaline (NA) reuptake inhibitors can improve exercise performance, despite hyperthermia during exercise in the heat. DA/NA reuptake inhibitors also increase catecholamine release in the thermoregulatory centre. Intracerebroventricularly injected DA has been shown to improve exercise performance through inhibiting hyperthermia-induced fatigue, even at normal ambient temperatures. Further, caffeine has been reported to increase DA release in the thermoregulatory centre and improves endurance exercise performance despite increased core body temperature. Taken together, DA has been shown to have ergogenic effects and increase heat storage and hyperthermia tolerance. The mechanisms underlying these effects seem to involve limiting/overriding the inhibitory signals from the central nervous system that result in cessation of exercise due to hyperthermia.

Cardioprotective effects of early and late aerobic exercise training in experimental pulmonary arterial hypertension.

PubMed

Moreira-Gonçalves, Daniel; Ferreira, Rita; Fonseca, Hélder; Padrão, Ana Isabel; Moreno, Nuno; Silva, Ana Filipa; Vasques-Nóvoa, Francisco; Gonçalves, Nádia; Vieira, Sara; Santos, Mário; Amado, Francisco; Duarte, José Alberto; Leite-Moreira, Adelino F; Henriques-Coelho, Tiago

2015-11-01

Clinical studies suggest that aerobic exercise can exert beneficial effects in pulmonary arterial hypertension (PAH), but the underlying mechanisms are largely unknown. We compared the impact of early or late aerobic exercise training on right ventricular function, remodeling and survival in experimental PAH. Male Wistar rats were submitted to normal cage activity (SED), exercise training in early (EarlyEX) and in late stage (LateEX) of PAH induced by monocrotaline (MCT, 60 mg/kg). Both exercise interventions resulted in improved cardiac function despite persistent right pressure-overload, increased exercise tolerance and survival, with greater benefits in EarlyEX+MCT. This was accompanied by improvements in the markers of cardiac remodeling (SERCA2a), neurohumoral activation (lower endothelin-1, brain natriuretic peptide and preserved vascular endothelial growth factor mRNA), metabolism and mitochondrial oxidative stress in both exercise interventions. EarlyEX+MCT provided additional improvements in fibrosis, tumor necrosis factor-alpha/interleukin-10 and brain natriuretic peptide mRNA, and beta/alpha myosin heavy chain protein expression. The present study demonstrates important cardioprotective effects of aerobic exercise in experimental PAH, with greater benefits obtained when exercise training is initiated at an early stage of the disease.

Physiological Tolerance to Uncompensable Heat Stress: Effects of Exercise Intensity, Protective Clothing, and Climate

DTIC Science & Technology

1994-01-01

Physiological tolerance to uncompensable heat stress: effects of exercise intensity, protective clothing , and climate SCOTT J. MONTAIN, MICHAEL N...effects of exercise 26), there remains little information to predict the inci- intensity, protective clothing , and climate. J. AppL PhysioL dence of...that pre- exercise intensity, protective clothing level, and climate on dict the physiological responses and work capability dur- physiological tolerance

Phase I/II randomized trial of aerobic exercise in Parkinson disease in a community setting.

PubMed

Uc, Ergun Y; Doerschug, Kevin C; Magnotta, Vincent; Dawson, Jeffrey D; Thomsen, Teri R; Kline, Joel N; Rizzo, Matthew; Newman, Sara R; Mehta, Sonya; Grabowski, Thomas J; Bruss, Joel; Blanchette, Derek R; Anderson, Steven W; Voss, Michelle W; Kramer, Arthur F; Darling, Warren G

2014-07-29

To (1) investigate effects of aerobic walking on motor function, cognition, and quality of life in Parkinson disease (PD), and (2) compare safety, tolerability, and fitness benefits of different forms of exercise intervention: continuous/moderate intensity vs interval/alternating between low and vigorous intensity, and individual/neighborhood vs group/facility setting. Initial design was a 6-month, 2 × 2 randomized trial of different exercise regimens in independently ambulatory patients with PD. All arms were required to exercise 3 times per week, 45 minutes per session. Randomization to group/facility setting was not feasible because of logistical factors. Over the first 2 years, we randomized 43 participants to continuous or interval training. Because preliminary analyses suggested higher musculoskeletal adverse events in the interval group and lack of difference between training methods in improving fitness, the next 17 participants were allocated only to continuous training. Eighty-one percent of 60 participants completed the study with a mean attendance of 83.3% (95% confidence interval: 77.5%-89.0%), exercising at 46.8% (44.0%-49.7%) of their heart rate reserve. There were no serious adverse events. Across all completers, we observed improvements in maximum oxygen consumption, gait speed, Unified Parkinson's Disease Rating Scale sections I and III scores (particularly axial functions and rigidity), fatigue, depression, quality of life (e.g., psychological outlook), and flanker task scores (p < 0.05 to p < 0.001). Increase in maximum oxygen consumption correlated with improvements on the flanker task and quality of life (p < 0.05). Our preliminary study suggests that aerobic walking in a community setting is safe, well tolerated, and improves aerobic fitness, motor function, fatigue, mood, executive control, and quality of life in mild to moderate PD. This study provides Class IV evidence that in patients with PD, an aerobic exercise program improves aerobic fitness, motor function, fatigue, mood, and cognition. © 2014 American Academy of Neurology.

Effect of pulmonary rehabilitation on balance in persons with chronic obstructive pulmonary disease.

PubMed

Beauchamp, Marla K; O'Hoski, Sachi; Goldstein, Roger S; Brooks, Dina

2010-09-01

To describe within-subject effects of pulmonary rehabilitation (PR) on balance in persons with chronic obstructive pulmonary disease (COPD) and to determine whether any observed changes in balance were associated with change in exercise tolerance or health-related quality of life. Single-arm longitudinal study. Inpatient PR center. Subjects with COPD (N=29; mean +/- SD age, 69.8+/-10.3y; forced expiratory volume in 1 second, 46.3%+/-22.3% predicted; 59% men [n=17]). A standardized 6-week multidisciplinary PR program (exercise training, breathing exercises, education, and psychologic support). Balance was assessed using the Berg Balance Scale (BBS), Timed Up and Go (TUG) test, and the Activities-Specific Balance Confidence (ABC) scale. Exercise tolerance was determined from the 6-minute walk test (6MWT), and health-related quality of life from the Chronic Respiratory Questionnaire (CRQ). Subjects showed small improvements in BBS (2.8+/-2.8 points; P<.001) and TUG (-1.5+/-2.4s; P=.003) scores, but not in ABC scores (4.8+/-15.4 points; P>.05). There was a weak relationship between change in BBS and change in CRQ scores (r=.40; P=.045) and no relationship with change in 6MWT. PR contributed to minor improvements in balance and had no effect on balance confidence in subjects with COPD. Further work is warranted to determine the optimal intervention for improving balance in this population.

Space Physiology Studies

NASA Technical Reports Server (NTRS)

Hargens, A. R.; Ballard, R. E.; Boda, W. L.; Ertl, A. C.; Schneider, S. M.; Hutchinson, K. J.; Lee, S. M.; Murthy, G.; Putcha, L.; Watenpaugh, D. E.

1999-01-01

Calculations suggest that exercise in space to date has lacked sufficient loads to maintain musculoskeletal mass. Lower body negative pressure (LBNP) produces a force at the feet equal to the product of the LBNP and body cross-sectional area at the waist. Supine exercise within 50-60 mm Hg LBNP improves tolerance to LBNP and produces forces similar to those occurring during upright posture on Earth. Thus, exercise within LBNP may help prevent deconditioning of astronauts by stressing tissues of the lower body in a manner similar to gravity and also, may provide a safe and effective alternative to centrifugation in terms of cost, mass, volume, and power usage. We hypothesize that supine treadmill exercise during LBNP at one body weight (50-60 mm Hg LBNP) will provide cardiovascular and musculoskeletal loads similar to those experienced while upright in lg. Also, daily supine treadmill running in a LBNP chamber will maintain aerobic fitness, orthostatic tolerance, and musculoskeletal structure and function during bed rest (simulated microgravity).

[The impact of comprehensive cardiac rehabilitation in patients up to 55 years old after acute myocardial infarction treated with primary coronary intervention].

PubMed

Piestrzeniewicz, Katarzyna; Navarro-Kuczborska, Natalia; Bolińska, Halina; Jegier, Anna; Maciejewski, Marek

2004-03-01

The aim of our study was to evaluate the impact of comprehensive 3-phases cardiac rehabilitation in patients aged up to 55 years after acute myocardial infarction treated with primary coronary intervention (PCI) of the infarction related artery on the cardiovascular status, modification of coronary risk factors, psychological and physical status and exercise tolerance. Out of 106 consecutive patients aged up to 55 years with acute myocardial infarction (AMI) with ST-segment elevation, treated with primary coronary intervention (PCI) of the infarction related artery 71 patients entered the study and were randomized either to the Study Group (GB) or to the Control Group (GK). 31 patients of GB underwent 3-phases cardiac rehabilitation program and 40 patients of GK did not participate in phase III of the program. At phase I of the rehabilitation and 6 months after myocardial infarction physical examination, echocardiography and treadmill exercise test were performed. At 6-months follow-up chest pain and symptoms of heart failure were significantly less common (p < 0.001) and a tendency for fewer new cardiac events and re-PCI was noted in GB. Self-evaluated, significantly greater improvement in the emotional and physical status as well as in physical activity (p < 0.001) was achieved in GB. In GB better exercise tolerance on treadmill exercise test, greater improvement in left ventricular ejection fraction (p < 0.05) and contractile index (p < 0.05) on echocardiography were observed. The effects of the secondary prevention in terms of smoking cessation and obesity were not satisfactory in both groups. 3-phases comprehensive cardiac rehabilitation in patients with AMI treated with PCI of the infarction related artery improves recovery at 6-month follow-up. It has a favorable impact on the anginal and heart failure symptoms, cardiac risk factors (especially physical activity, restrictive diet), psychological and physical status. It contributes towards maintaining a further event-free period. It improves selected cardiovascular parameters such as exercise tolerance, segmental and global left ventricular function.

Is exercise training safe and beneficial in patients receiving left ventricular assist device therapy?

PubMed

Alsara, Osama; Perez-Terzic, Carmen; Squires, Ray W; Dandamudi, Sanjay; Miranda, William R; Park, Soon J; Thomas, Randal J

2014-01-01

Because a limited number of patients receive heart transplantation, alternative therapies, such as left ventricular assist device (LVAD) therapy, have emerged. Published studies have shown that LVAD implantation, by itself, improves exercise tolerance to the point where it is comparable to those with mild heart failure. The improvement in exercise capacity is maximally achieved 12 weeks after LVAD therapy and can continue even after explantation of the device. This effect varies, depending on the type of LVAD and exercise training. The available data in the literature on safety and benefits of exercise training in patients after LVAD implantation are limited, but the data that are available suggest that training trends to be safe and have an impact on exercise capacity in LVAD patients. Although no studies were identified on the role of cardiac rehabilitation programs in the management of LVAD patients, it appears that cardiac rehabilitation programs offer an ideal setting for the provision of supervised exercise training in this patient group.

Exercise detraining: Applicability to microgravity

NASA Technical Reports Server (NTRS)

Coyle, Edward F.

1994-01-01

Physical training exposes the various systems of the body to potent physiologic stimuli. These stimuli induce specific adaptations that enhance an individual's tolerance for the type of exercise encountered in training. The level of adaptation and the magnitude of improvement in exercise tolerance is proportional to the potency of the physical training stimuli. Likewise, our bodies are stimulated by gravity, which promotes adaptations of both the cardiovascular and skeletal muscles. Exposure to microgravity removes normal stimuli to these systems, and the body adapts to these reduced demands. In many respects the cessation of physical training in athletes and the transition from normal gravity to microgravity represent similar paradigms. Inherent to these situations is the concept of the reversibility of the adaptations induced by training or by exposure to normal gravity. The reversibility concept holds that when physical training is stopped (i.e., detraining) or reduced, or a person goes from normal gravity to microgravity, the bodily systems readjust in accordance with the diminished physiologic stimuli. The focus of this chapter is on the time course of loss of the adaptations to endurance training as well as on the possibility that certain adaptations persist, to some extent, when training is stopped. Because endurance exercise training generally improves cardiovascular function and promotes metabolic adaptations within the exercising skeletal musculature, the reversibility of these specific adaptations is considered. These observations have some applicability to the transition from normal to microgravity.

The efficacy of aerobic exercise and resistance training as transdiagnostic interventions for anxiety-related disorders and constructs: A randomized controlled trial.

PubMed

LeBouthillier, Daniel M; Asmundson, Gordon J G

2017-12-01

Evidence supports exercise as an intervention for many mental health concerns; however, randomized controlled investigations of the efficacy of different exercise modalities and predictors of change are lacking. The purposes of the current trial were to: (1) quantify the effects of aerobic exercise and resistance training on anxiety-related disorder (including anxiety disorders, obsessive-compulsive disorder, and posttraumatic stress disorder) status, symptoms, and constructs, (2) evaluate whether both modalities of exercise were equivalent, and (3) to determine whether exercise enjoyment and physical fitness are associated with symptom reduction. A total of 48 individuals with anxiety-related disorders were randomized to aerobic exercise, resistance training, or a waitlist. Symptoms of anxiety-related disorders, related constructs, and exercise enjoyment were assessed at pre-intervention and weekly during the 4-week intervention. Participants were further assessed 1-week and 1-month post-intervention. Both exercise modalities were efficacious in improving disorder status. As well, aerobic exercise improved general psychological distress and anxiety, while resistance training improved disorder-specific symptoms, anxiety sensitivity, distress tolerance, and intolerance of uncertainty. Physical fitness predicted reductions in general psychological distress for both types of exercise and reductions in stress for aerobic exercise. Results highlight the efficacy of different exercise modalities in uniquely addressing anxiety-related disorder symptoms and constructs. Copyright © 2017 Elsevier Ltd. All rights reserved.

Virtual reality bringing a new reality to postthoracotomy lung cancer patients via a home-based exercise intervention targeting fatigue while undergoing adjuvant treatment.

PubMed

Hoffman, Amy J; Brintnall, Ruth Ann; Brown, Jean K; von Eye, Alexander; Jones, Lee W; Alderink, Gordon; Ritz-Holland, Deborah; Enter, Mark; Patzelt, Lawrence H; VanOtteren, Glenn M

2014-01-01

Little is known about rehabilitation for postthoracotomy non-small cell lung cancer (NSCLC) patients. This research uses a perceived self-efficacy-enhancing light-intensity exercise intervention targeting a priority symptom, cancer-related fatigue (CRF), for postthoracotomy NSCLC patients. This article reports on phase II of a 2-phase study. Phase I focused on initiation and tolerance of exercise during the 6 weeks immediately after thoracotomy, whereas phase II addressed maintenance of exercise for an additional 10 weeks including participants initiating and completing chemotherapy and/or radiation therapy. The objective of this study was to investigate the feasibility, acceptability, and preliminary efficacy of an exercise intervention for postthoracotomy NSCLC patients to include those initiating and completing adjuvant therapy. A single-arm design composed of 7 participants postthoracotomy for NSCLC performed light-intensity exercises using an efficacy-enhancing virtual-reality approach using the Nintendo Wii Fit Plus. Despite most participants undergoing chemotherapy and/or radiation therapy, participants adhered to the intervention at a rate of 88% with no adverse events while giving the intervention high acceptability scores on conclusion. Likewise, participants' CRF scores improved from initiation through the conclusion of the intervention with perceived self-efficacy for walking at a light intensity continuously for 60 minutes, improving significantly upon conclusion over presurgery values. Postthoracotomy NSCLC patients maintained exercise for an additional 10 weeks while undergoing adjuvant therapy showing rehabilitation potential because the exercise intervention was feasible, safe, well tolerated, and highly acceptable showing positive changes in CRF self-management. A randomized controlled trial is needed to further investigate these relationships.

Comparison between pre-exercise casein peptide and intact casein supplementation on glucose tolerance in mice fed a high-fat diet.

PubMed

Matsunaga, Yutaka; Tamura, Yuki; Sakata, Yasuyuki; Nonaka, Yudai; Saito, Noriko; Nakamura, Hirohiko; Shimizu, Takashi; Takeda, Yasuhiro; Terada, Shin; Hatta, Hideo

2018-04-01

We hypothesized that along with exercise, casein peptide supplementation would have a higher impact on improving glucose tolerance than intact casein. Male 6-week-old ICR mice were provided a high-fat diet to induce obesity and glucose intolerance. The mice were randomly divided into 4 treatment groups: control (Con), endurance training (Tr), endurance training with intact casein supplementation (Cas+Tr), and endurance training with casein peptide supplementation (CP+Tr). The mice in each group were orally administrated water, intact casein, or casein peptide (1.0 mg/g body weight, every day), and then subjected to endurance training (15-25 m/min, 60 min, 5 times/week for 4 weeks) on a motor-driven treadmill 30 min after ingestion. Our results revealed that total intra-abdominal fat was significantly lower in CP+Tr than in Con (p < 0.05). Following an oral glucose tolerance test, the blood glucose area under the curve (AUC) was found to be significantly smaller for CP+Tr than for Con (p < 0.05). Moreover, in the soleus muscle, glucose transporter 4 (GLUT4) protein levels were significantly higher in CP+Tr than in Con (p < 0.01). However, intra-abdominal fat, blood glucose AUC, and GLUT4 protein content in the soleus muscle did not alter in Tr and Cas+Tr when compared with Con. These observations suggest that pre-exercise casein peptide supplementation has a higher effect on improving glucose tolerance than intact casein does in mice fed a high-fat diet.

Aerobic vs. resistance exercise in non-alcoholic fatty liver disease: A systematic review.

PubMed

Hashida, Ryuki; Kawaguchi, Takumi; Bekki, Masafumi; Omoto, Masayuki; Matsuse, Hiroo; Nago, Takeshi; Takano, Yoshio; Ueno, Takato; Koga, Hironori; George, Jacob; Shiba, Naoto; Torimura, Takuji

2017-01-01

Exercise is a first-line therapy for patients with non-alcoholic fatty liver disease (NAFLD). We sought to: 1) summarize effective aerobic and resistance exercise protocols for NAFLD; and 2) compare the effects and energy consumption of aerobic and resistance exercises. A literature search was performed using PubMed, Web of Science, and Scopas to January 28, 2016. From a total of 95 articles, 23 studies including 24 aerobic and 7 resistance exercise protocols were selected for the summary of exercise protocols. Twelve articles including 13 aerobic and 4 resistance exercise protocols were selected for the comparative analysis. For aerobic exercise, the median effective protocol was 4.8 metabolic equivalents (METs) for 40min/session, 3times/week for 12weeks. For resistance exercise, the median effective protocol was 3.5 METs for 45min/session, 3times/week for 12weeks. Aerobic and resistance exercise improved hepatic steatosis. No significant difference was seen in the duration, frequency, or period of exercise between the two exercise groups; however, %VO 2 max and energy consumption were significantly lower in the resistance than in the aerobic group (50% [45-98] vs. 28% [28-28], p=0.0034; 11,064 [6394-21,087] vs. 6470 [4104-12,310] kcal/total period, p=0.0475). Resistance exercise improves NAFLD with less energy consumption. Thus, resistance exercise may be more feasible than aerobic exercise for NAFLD patients with poor cardiorespiratory fitness or for those who cannot tolerate or participate in aerobic exercise. These data may indicate a possible link between resistance exercise and lipid metabolism in the liver. Both aerobic and resistance exercise reduce hepatic steatosis in non-alcoholic fatty liver disease (NAFLD) with similar frequency, duration, and period of exercise (40-45min/session 3times/week for 12weeks); however, the two forms of exercise have different characteristics. Intensity and energy consumption were significantly lower for resistance than for aerobic exercise. Resistance exercise may be more feasible than aerobic exercise for NAFLD patients with poor cardiorespiratory fitness or for those who cannot tolerate or participate in aerobic exercise. Copyright © 2016 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

A pilot study of pulmonary rehabilitation and chest physiotherapy versus chest physiotherapy alone in bronchiectasis.

PubMed

Mandal, P; Sidhu, M K; Kope, L; Pollock, W; Stevenson, L M; Pentland, J L; Turnbull, K; Mac Quarrie, S; Hill, A T

2012-12-01

The aim of our study was to assess the efficacy of pulmonary rehabilitation in addition to regular chest physiotherapy in non cystic fibrosis bronchiectasis. Thirty patients with clinically significant bronchiectasis and limited exercise tolerance were randomized into either the control group receiving chest physiotherapy (8 weeks) or into the intervention group, receiving pulmonary rehabilitation in addition to chest physiotherapy (8 weeks). Both groups were encouraged to maintain their exercise program and or chest physiotherapy, following completion of the study. End of training (8 weeks) No improvement in control group. In the intervention group, incremental shuttle walk test (ISWT) improved by 56.7 m (p = 0.03), endurance walk test (EWT) by 193.3 m (p = 0.01), Leicester Cough Questionnaire (LCQ) improved by 2.6 units (p < 0.001) and St. George's Respiratory Questionnaire (SGRQ) by 8 units (p < 0.001). At 20 weeks (12 weeks post end of training) No improvement in control group. In the intervention group, ISWT improved by 80 m (p = 0.04) and EWT by 247.5 m (p = 0.003). LCQ improved by 4.4 units (p < 0.001) and SGRQ by 4 units (p < 0.001). Pulmonary rehabilitation in addition to regular chest physiotherapy, improves exercise tolerance and health related quality of life in non cystic fibrosis bronchiectasis and the benefit was sustained at 12 weeks post end of pulmonary rehabilitation. Clinical trials regn no. NCT00868075. Copyright © 2012 Elsevier Ltd. All rights reserved.

Exercise effects on fitness, lipids, glucose tolerance and insulin levels in young adults.

PubMed

Israel, R G; Davidson, P C; Albrink, M J; Krall, J M

1981-07-01

The effect of 3 different physical training programs on cardiorespiratory (cr) fitness, fasting plasma lipids, glucose and insulin levels, and scapular skinfold thickness was assessed in 64 healthy college men. Training sessions were held 4 times a week for 5 weeks. The cr fitness improved significantly and skinfold thickness decreased following the aerobic, the pulse workout (interval training), and the anaerobic training compared to the control group. Skinfold thickness, plasma insulin, and triglyceride concentrations were significantly intercorrelated before and after training. The exercise programs had no significant effect on plasma cholesterol, triglycerides, phospholipids, glucose tolerance, or insulin levels. Change in adipose mass was thus dissociated from change in plasma insulin and triglyceride concentrations. It was concluded that in young men plasma triglycerides, the lipid component mostly readily reduced by exercise, were too low to be reduced further by a physical training program.

[Supervised exercise training in patients with pulmonary arterial hypertension - analyses of the effectiveness and safety].

PubMed

Saxer, S; Rhyner, M; Treder, U; Speich, R; van Gestel, A J R

2012-02-01

Both in today's scientific research and in clinical practice, there exists a need to address the uncertainty concerning the effectiveness and safety of cardiopulmonary exercise training (CPET) in patients with pulmonary arterial hypertension (PAH). It is commonly believed that CPET may be dangerous for patients with PAH, because increasing pressure on the pulmonary arteries may worsen right-sided heart failure. Recently, the first clinical trials on exercise training in patients with pulmonary hypertension reported promising results. Extension of the walking distance at the 6-minute walk test improved quality of life, endurance capacity and a reduction in symptoms were observed after CPET. Furthermore, CPET was well tolerated by the patients in five clinical trials. In conclusion, it may be postulated that CPET is an effective therapy in patients with PAH and was tendentially well tolerated by the patients.

The 'sensory tolerance limit': A hypothetical construct determining exercise performance?

PubMed

Hureau, Thomas J; Romer, Lee M; Amann, Markus

2018-02-01

Neuromuscular fatigue compromises exercise performance and is determined by central and peripheral mechanisms. Interactions between the two components of fatigue can occur via neural pathways, including feedback and feedforward processes. This brief review discusses the influence of feedback and feedforward mechanisms on exercise limitation. In terms of feedback mechanisms, particular attention is given to group III/IV sensory neurons which link limb muscle with the central nervous system. Central corollary discharge, a copy of the neural drive from the brain to the working muscles, provides a signal from the motor system to sensory systems and is considered a feedforward mechanism that might influence fatigue and consequently exercise performance. We highlight findings from studies supporting the existence of a 'critical threshold of peripheral fatigue', a previously proposed hypothesis based on the idea that a negative feedback loop operates to protect the exercising limb muscle from severe threats to homeostasis during whole-body exercise. While the threshold theory remains to be disproven within a given task, it is not generalisable across different exercise modalities. The 'sensory tolerance limit', a more theoretical concept, may address this issue and explain exercise tolerance in more global terms and across exercise modalities. The 'sensory tolerance limit' can be viewed as a negative feedback loop which accounts for the sum of all feedback (locomotor muscles, respiratory muscles, organs, and muscles not directly involved in exercise) and feedforward signals processed within the central nervous system with the purpose of regulating the intensity of exercise to ensure that voluntary activity remains tolerable.

Exercise and gastrointestinal function and disease: an evidence-based review of risks and benefits.

PubMed

Bi, Luke; Triadafilopoulos, George

2003-09-01

Exercise is beneficial to health because it reduces the risk of cardiovascular and endocrine diseases, improves bone and muscle conditioning, and lessens anxiety and depression. However, the impact of exercise on the gastrointestinal system has been conflicting. This systematic literature review evaluates the effect of the different modes and intensity levels of exercise on gastrointestinal function and disease using an evidence-based approach. Although more applicable to trained athletes and individuals who are highly active and, as such, at risk to experience the side-effects of exercise, an effort was made to state the level or degree of exercise or the lack of such evidence. Light and moderate exercise is well tolerated and can benefit patients with inflammatory bowel disease and liver disease. Physical activity can also improve gastric emptying and lower the relative risk of colon cancer in most populations. Severe, exhaustive exercise, however, inhibits gastric emptying, interferes with gastrointestinal absorption, and causes many gastrointestinal symptoms, most notably gastrointestinal bleeding. This knowledge will enable physicians to prescribe physical exercise in health and disease and to better manage patients with exercise-related gastrointestinal disorders. Our understanding of exercise and its gastrointestinal manifestations as well as risks and benefits warrants further investigation.

Increasing discomfort tolerance predicts incentive senitization of exercise reinforcement: Preliminary results from a randomized controlled intervention to increase the reinforcing value of exercise in overweight to obese adu

USDA-ARS?s Scientific Manuscript database

Objective: The reinforcing (motivating) value of exercise/physical activity (RRVex) predicts usual exercise behavior and meeting of physical activity guidelines. Recent cross-sectional evidence suggests, for the first time, that greater tolerance for the discomfort experienced during exercise is ass...

Physical self-concept and its link to cardiopulmonary exercise tolerance among adolescents with mild congenital heart disease.

PubMed

Chen, Chi-Wen; Su, Wen-Jen; Wang, Jou-Kou; Yang, Hsiao-Ling; Chiang, Yueh-Tao; Moons, Philip

2015-06-01

Due to medical advances, most children with congenital heart disease (CHD) are expected to survive into adulthood. Establishing adequate physical self-concept and cardiopulmonary tolerance during the adolescent period can primarily enhance overall well-being. The purpose of this study was to undertake a gender-specific evaluation of the domain of physical self-concept among adolescents with mild CHD, and to examine the relationships between physical self-concept and cardiopulmonary exercise tolerance among adolescents with mild CHD. Four hundred and thirteen adolescents 12-20 years of age, whose cardiologists had not recommended any limitation of exercise, completed Physical Self-Description Questionnaires and three-minute step tests in two outpatient cardiology departments. The male participants had significantly greater scores in measures of overall physical self-concept, competence in sports, physical appearance, body fat, physical activity, endurance, and strength than did the female participants. More than 80% of the participants had at least an average cardiopulmonary exercise tolerance index. The perception of not being 'too fat' and being more physically active were significant correlates of better cardiopulmonary exercise tolerance for adolescents with mild CHD. The results provided evidence for gender-specific evaluation of domains of physical self-concept among adolescents with mild CHD. The three-minute step test to measure cardiopulmonary exercise tolerance in adolescents with mild CHD may be an appropriate objective measure for use in future research. Continued efforts are needed in early intervention to promote cardiopulmonary exercise tolerance. © The European Society of Cardiology 2014.

Exercise-induced cardioprotection--biochemical, morphological and functional evidence in whole tissue and isolated mitochondria.

PubMed

Ascensão, António; Ferreira, Rita; Magalhães, José

2007-04-12

Myocardial injury is a major contributor to the morbidity and mortality associated with coronary artery disease. Regular exercise has been confirmed as a pragmatic countermeasure to protect against cardiac injury. Specifically, endurance exercise has been proven to provide cardioprotection against cardiac insults in both young and old animals. Proposed mechanisms to explain the cardioprotective effects of exercise are mediated, at least partially, by redox changes and include the induction of myocardial heat shock proteins, improved cardiac antioxidant capacity, and/or elevation of other cardioprotective molecules. Understanding the molecular basis for exercise-induced cardioprotection is important in developing exercise strategies to protect the heart during and after insults. Data suggest that these positive modulator effects occur at different levels of cellular organization, being mitochondria fundamental organelles that are sensitive to disturbances imposed by exercise on basal homeostasis. At present, which of these protective mechanisms is essential for exercise-induced cardioprotection remains unclear. This review analyzes the biochemical, morphological and functional outcomes of acute and chronic exercise on the overall cardiac muscle tissue and in isolated mitochondria. Some redox-based mechanisms behind the cross-tolerance effects particularly induced by endurance training, against certain stressors responsible for the impairments in cardiac homeostasis caused by aging, diabetes, drug administration or ischemia-reperfusion are also outlined. Further work should be addressed in order to clarify the precise regulatory mechanisms by which physical exercise augments heart tolerance against many cardiotoxic agents.

Deconditioning-induced exercise responses as influenced by heat acclimation

NASA Technical Reports Server (NTRS)

Shvartz, E.; Bhattacharya, A.; Sperinde, S. J.; Brock, P. J.; Sciaraffa, D.; Haines, R. F.; Greenleaf, J. E.

1979-01-01

A study to determine the effect of heat acclimation and physical training in temperate conditions on changes in exercise tolerance following water-immersion deconditioning is presented. Five young men were tested on a bicycle ergometer before and after heat acclimation and after water immersion. The subjects and the experimental procedure, heat acclimation and exercise training, water immersion, and exercise tolerance are discussed. Heat acclimation resulted in the usual decreases in exercise heart rate and rectal temperature and an increase in sweat rate. Water immersion resulted in substantial diuresis despite water consumed. The results show that heat acclimation provides an effective method of preventing the adverse effects of water-immersion deconditioning on exercise tolerance.

Muscle electrical stimulation improves neurovascular control and exercise tolerance in hospitalised advanced heart failure patients.

PubMed

Groehs, Raphaela V; Antunes-Correa, Ligia M; Nobre, Thais S; Alves, Maria-Janieire Nn; Rondon, Maria Urbana Pb; Barreto, Antônio Carlos Pereira; Negrão, Carlos E

2016-10-01

We investigated the effects of muscle functional electrical stimulation on muscle sympathetic nerve activity and muscle blood flow, and, in addition, exercise tolerance in hospitalised patients for stabilisation of heart failure. Thirty patients hospitalised for treatment of decompensated heart failure, class IV New York Heart Association and ejection fraction ≤ 30% were consecutively randomly assigned into two groups: functional electrical stimulation (n = 15; 54 ± 2 years) and control (n = 15; 49 ± 2 years). Muscle sympathetic nerve activity was directly recorded via microneurography and blood flow by venous occlusion plethysmography. Heart rate and blood pressure were evaluated on a beat-to-beat basis (Finometer), exercise tolerance by 6-minute walk test, quadriceps muscle strength by a dynamometer and quality of life by Minnesota questionnaire. Functional electrical stimulation consisted of stimulating the lower limbs at 10 Hz frequency, 150 ms pulse width and 70 mA intensity for 60 minutes/day for 8-10 consecutive days. The control group underwent electrical stimulation at an intensity of < 20 mA. Baseline characteristics were similar between groups, except age that was higher and C-reactive protein and forearm blood flow that were smaller in the functional electrical stimulation group. Functional electrical stimulation significantly decreased muscle sympathetic nerve activity and increased muscle blood flow and muscle strength. No changes were found in the control group. Walking distance and quality of life increased in both groups. However, these changes were greater in the functional electrical stimulation group. Functional electrical stimulation improves muscle sympathetic nerve activity and vasoconstriction and increases exercise tolerance, muscle strength and quality of life in hospitalised heart failure patients. These findings suggest that functional electrical stimulation may be useful to hospitalised patients with decompensated chronic heart failure. © The European Society of Cardiology 2016.

Effect of a combination of whole body vibration exercise and squat training on body balance, muscle power, and walking ability in the elderly.

PubMed

Osugi, Tomohiro; Iwamoto, Jun; Yamazaki, Michio; Takakuwa, Masayuki

2014-01-01

A randomized controlled trial was conducted to clarify the beneficial effect of whole body vibration (WBV) exercise plus squat training on body balance, muscle power, and walking ability in the elderly with knee osteoarthritis and/or spondylosis. Of 35 ambulatory patients (14 men and 21 women) who were recruited at our outpatient clinic, 28 (80.0%, 12 men and 16 women) participated in the trial. The subjects (mean age 72.4 years) were randomly divided into two groups (n=14 in each group), ie, a WBV exercise alone group and a WBV exercise plus squat training group. A 4-minute WBV exercise (frequency 20 Hz) was performed 2 days per week in both groups; squat training (20 times per minute) was added during the 4-minute WBV training session in the WBV exercise plus squat training group. The duration of the trial was 6 months. The exercise and training program was safe and well tolerated. WBV exercise alone improved indices of body balance and walking velocity from baseline values. However, WBV exercise plus squat training was more effective for improving tandem gait step number and chair-rising time compared with WBV exercise alone. These results suggest the benefit and safety of WBV exercise plus squat training for improving physical function in terms of body balance and muscle power in the elderly.

Lack of independent effect of type 2 diabetes beyond characteristic comorbidities and medications on small muscle mass exercising muscle blood flow and exercise tolerance.

PubMed

Poitras, Veronica J; Bentley, Robert F; Hopkins-Rosseel, Diana H; LaHaye, Stephen A; Tschakovsky, Michael E

2015-08-01

Persons with type 2 diabetes (T2D) are believed to have reduced exercise tolerance; this may be partly due to impaired exercising muscle blood flow (MBF). Whether there is an impact of T2D on exercising MBF within the typical constellation of comorbidities (hypertension, dyslipidemia, obesity) and their associated medications has not been investigated. We tested the hypothesis that small muscle mass exercise tolerance is reduced in persons with T2D versus Controls (matched for age, body mass index, fitness, comorbidities, non-T2D medications) and that this is related to blunted MBF. Eight persons with T2D and eight controls completed a forearm critical force (fCFimpulse) test as a measure of exercise tolerance (10-min intermittent maximal effort forearm contractions; the average contraction impulse in the last 30 sec quantified fCFimpulse). Forearm blood flow (FBF; ultrasound) and mean arterial pressure (MAP; finger photoplethysmography) were measured; forearm vascular conductance (FVK) was calculated. Data are means ± SD, T2D versus Control. fCFimpulse was not different between groups (136.9 ± 47.3  N·sec vs. 163.1 ± 49.7 N·sec, P = 0.371) nor was the ∆FBF from rest to during exercise at fCFimpulse (502.9 ± 144.6 vs. 709.1 ± 289.2 mL/min, P = 0.092), or its determinants ∆FVK and ∆MAP (both P > 0.05), although there was considerable interindividual variability. ∆FBF was strongly related to fCFimpulse (r = 0.727, P = 0.002), providing support for the relationship between oxygen delivery and exercise tolerance. We conclude that small muscle mass exercising MBF and exercise tolerance are not impaired in representative persons with T2D versus appropriately matched controls. This suggests that peripheral vascular control impairment does not contribute to reduced exercise tolerance in this population. © 2015 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

Lack of independent effect of type 2 diabetes beyond characteristic comorbidities and medications on small muscle mass exercising muscle blood flow and exercise tolerance

PubMed Central

Poitras, Veronica J; Bentley, Robert F; Hopkins-Rosseel, Diana H; LaHaye, Stephen A; Tschakovsky, Michael E

2015-01-01

Persons with type 2 diabetes (T2D) are believed to have reduced exercise tolerance; this may be partly due to impaired exercising muscle blood flow (MBF). Whether there is an impact of T2D on exercising MBF within the typical constellation of comorbidities (hypertension, dyslipidemia, obesity) and their associated medications has not been investigated. We tested the hypothesis that small muscle mass exercise tolerance is reduced in persons with T2D versus Controls (matched for age, body mass index, fitness, comorbidities, non-T2D medications) and that this is related to blunted MBF. Eight persons with T2D and eight controls completed a forearm critical force (fCFimpulse) test as a measure of exercise tolerance (10-min intermittent maximal effort forearm contractions; the average contraction impulse in the last 30 sec quantified fCFimpulse). Forearm blood flow (FBF; ultrasound) and mean arterial pressure (MAP; finger photoplethysmography) were measured; forearm vascular conductance (FVK) was calculated. Data are means ± SD, T2D versus Control. fCFimpulse was not different between groups (136.9 ± 47.3  N·sec vs. 163.1 ± 49.7 N·sec, P = 0.371) nor was the ΔFBF from rest to during exercise at fCFimpulse (502.9 ± 144.6 vs. 709.1 ± 289.2 mL/min, P = 0.092), or its determinants ΔFVK and ΔMAP (both P > 0.05), although there was considerable interindividual variability. ΔFBF was strongly related to fCFimpulse (r = 0.727, P = 0.002), providing support for the relationship between oxygen delivery and exercise tolerance. We conclude that small muscle mass exercising MBF and exercise tolerance are not impaired in representative persons with T2D versus appropriately matched controls. This suggests that peripheral vascular control impairment does not contribute to reduced exercise tolerance in this population. PMID:26265750

Exercise increases pressure pain tolerance but not pressure and heat pain thresholds in healthy young men.

PubMed

Vaegter, H B; Hoeger Bement, M; Madsen, A B; Fridriksson, J; Dasa, M; Graven-Nielsen, T

2017-01-01

Exercise causes an acute decrease in the pain sensitivity known as exercise-induced hypoalgesia (EIH), but the specificity to certain pain modalities remains unknown. This study aimed to compare the effect of isometric exercise on the heat and pressure pain sensitivity. On three different days, 20 healthy young men performed two submaximal isometric knee extensions (30% maximal voluntary contraction in 3 min) and a control condition (quiet rest). Before and immediately after exercise and rest, the sensitivity to heat pain and pressure pain was assessed in randomized and counterbalanced order. Cuff pressure pain threshold (cPPT) and pain tolerance (cPTT) were assessed on the ipsilateral lower leg by computer-controlled cuff algometry. Heat pain threshold (HPT) was recorded on the ipsilateral foot by a computer-controlled thermal stimulator. Cuff pressure pain tolerance was significantly increased after exercise compared with baseline and rest (p < 0.05). Compared with rest, cPPT and HPT were not significantly increased by exercise. No significant correlation between exercise-induced changes in HPT and cPPT was found. Test-retest reliability before and after the rest condition was better for cPPT and CPTT (intraclass correlation > 0.77) compared with HPT (intraclass correlation = 0.54). The results indicate that hypoalgesia after submaximal isometric exercise is primarily affecting tolerance of pressure pain compared with the pain threshold. These data contribute to the understanding of how isometric exercise influences pain perception, which is necessary to optimize the clinical utility of exercise in management of chronic pain. The effect of isometric exercise on pain tolerance may be relevant for patients in chronic musculoskeletal pain as a pain-coping strategy. WHAT DOES THIS STUDY ADD?: The results indicate that hypoalgesia after submaximal isometric exercise is primarily affecting tolerance of pressure pain compared with the heat and pressure pain threshold. These data contribute to the understanding of how isometric exercise influences pain perception, which is necessary to optimize the clinical utility of exercise in management of chronic pain. © 2016 European Pain Federation - EFIC®.

[Effects of exercise therapy at the intensity of anaerobic threshold for exercise tolerance in patients with chronic stable coronary artery disease].

PubMed

Che, Lin; Gong, Zhu; Jiang, Jin-fa; Xu, Wen-jun; Deng, Bing; Xu, Jia-hong; Yan, Wen-wen; Zhang, Qi-ping; Wang, Le-min

2011-06-28

To investigate the effects of exercise therapy at the intensity of anaerobic threshold (AT) for exercise tolerance in patients with chronic stable coronary artery disease. Forty-three patients with chronic stable coronary artery disease (3 patients after coronary arterial bypass graft (CABG) surgery, 22 patients with old myocardial infarction and 18 unstable angina pectoris undergoing successful percutaneous coronary intervention (PCI) finished twice cardiopulmonary exercise test (CPET) and followed their rehabilitation program for 3 months. Thirty-two patients finished their aerobic exercise therapy based on their individual anaerobic thresholds while 11 patients had no exercise therapy. The heart rate at AT intensity (97 ± 9/min) was lower than their traditional minimal target heart rate (112 ± 7/min) and lower than heart rate (115 ± 11/min) at ischemic threshold post-CPET. The O(2) consumption (10.7 ± 2.4 to 12.6 ± 2.9 ml×min(-1)×kg(-1)) (P = 0.04) and workload (37 ± 18 to 47 ± 13 J/s) (P = 0.04) at AT level and the O(2) consumption (15.3 ± 3.1 to 20.6 ± 4.2 ml×min(-1)×kg(-1), P = 0.02) and workload(68 ± 12 and 87 ± 14 J/s, P = 0.01) at peak level markedly increased after 3 months in the exercise group. And the O(2) consumption (15.3 ± 2.9 to 16.2 ± 3.1 ml×min(-1)×kg(-1)) and workload (65 ± 13 to 73 ± 16 J/s) at peak level mild increased after 3 months in the non-exercise group, but their O(2) consumption (11.0 ± 2.7 to 11.3 ± 2.8 ml×min(-1)×kg(-1)) and workload (38 ± 11 to 37 ± 9 J/s) at AT level had no obvious change. AT exercise intensity was lower than ischemic threshold post-CPET. Exercise therapy at the intensity of anaerobic threshold can improve oxygen capacity and exercise tolerance.

[Application of the 6-Minute Walking Test and Shuttle Walking Test in the Exercise Tests of Patients With COPD].

PubMed

Ho, Chiung-Fang; Maa, Suh-Hwa

2016-08-01

Exercise training improves the management of stable chronic obstructive pulmonary disease (COPD). COPD patients benefit from exercise training programs in terms of improved VO2 peak values and decreased dyspnea, fatigue, hospital admissions, and rates of mortality, increasing exercise capacity and health-related quality of life (HRQOL). COPD is often associated with impairment in exercise tolerance. About 51% of patients have a limited capacity for normal activity, which often further degrades exercise capacity, creating a vicious circle. Exercise testing is highly recommended to assess a patient's individualized functions and limitations in order to determine the optimal level of training intensity prior to initiating an exercise-training regimen. The outcomes of exercise testing provide a powerful indicator of prognosis in COPD patients. The six-minute walking test (6MWT) and the incremental shuttle-walking test (ISWT) are widely used in exercise testing to measure a patient's exercise ability by walking distances. While nursing-related articles published in Taiwan frequently cite and use the 6MWT to assess exercise capacity in COPD patients, the ISWT is rarely used. This paper introduces the testing method, strengths and weaknesses, and application of the two tests in order to provide clinical guidelines for assessing the current exercise capacity of COPD patients.

Effects of water drinking on cardiovascular responses to supine exercise and on orthostatic hypotension after exercise in pure autonomic failure.

PubMed

Humm, A M; Mason, L M; Mathias, C J

2008-10-01

Patients with pure autonomic failure (PAF) have an abnormal fall in blood pressure (BP) with supine exercise and exacerbation of orthostatic hypotension (OH) after exercise. This study assessed the pressor effect of water on the cardiovascular responses to supine exercise and on OH after exercise. 8 patients with PAF underwent a test protocol consisting of standing for 5 min, supine rest for 10 min, supine exercise by pedalling a cycle ergometer at workloads of 25, 50 and 75 W (each for 3 min), supine rest for 10 min and standing for 5 min. The test protocol was performed without water ingestion and on a separate occasion after 480 ml of distilled water immediately after pre-exercise standing. Beat to beat cardiovascular indices were measured with the Portapres II device with subsequent Modelflow analysis. All patients had severe OH pre-exercise (BP fall systolic 65.0 (26.1) mm Hg, diastolic 22.7 (13.5) mm Hg), with prompt recovery of BP in the supine position. 5 min after water drinking, there was a significant rise in BP in the supine position. With exercise, there was a clear fall in BP (systolic 42.1 (24.4) mm Hg, diastolic 25.9 (10.0) mm Hg) with a modest rise in heart rate; this occurred even after water ingestion (BP fall systolic 49.8 (18.9) mm Hg, diastolic 26.0 (9.1) mm Hg). BP remained low after exercise but was significantly higher after water intake, resulting in better tolerance of post-exercise standing. Water drinking did not change the abnormal cardiovascular responses to supine exercise. However, water drinking improved orthostatic tolerance post-exercise.

Home-based pulmonary rehabilitation improves clinical features and systemic inflammation in chronic obstructive pulmonary disease patients.

PubMed

do Nascimento, Eloisa Sanches Pereira; Sampaio, Luciana Maria Malosá; Peixoto-Souza, Fabiana Sobral; Dias, Fernanda Dultra; Gomes, Evelim Leal Freitas Dantas; Greiffo, Flavia Regina; Ligeiro de Oliveira, Ana Paula; Stirbulov, Roberto; Vieira, Rodolfo Paula; Costa, Dirceu

2015-01-01

Chronic obstructive pulmonary disease (COPD) is a respiratory disease characterized by chronic airflow limitation that leads beyond the pulmonary changes to important systemic effects. COPD is characterized by pulmonary and systemic inflammation. However, increases in the levels of inflammatory cytokines in plasma are found even when the disease is stable. Pulmonary rehabilitation improves physical exercise capacity and quality of life and decreases dyspnea. The aim of this study was to evaluate whether a home-based pulmonary rehabilitation (HBPR) program improves exercise tolerance in COPD patients, as well as health-related quality of life and systemic inflammation. This prospective study was conducted at the Laboratory of Functional Respiratory Evaluation, Nove de Julho University, São Paulo, Brazil. After anamnesis, patients were subjected to evaluations of health-related quality of life and dyspnea, spirometry, respiratory muscle strength, upper limbs incremental test, incremental shuttle walk test, and blood test for quantification of systemic inflammatory markers (interleukin [IL]-6 and IL-8). At the end of the evaluations, patients received a booklet containing the physical exercises to be performed at home, three times per week for 8 consecutive weeks. Around 25 patients were enrolled, and 14 completed the pre- and post-HBPR ratings. There was a significant increase in the walked distance and the maximal inspiratory pressure, improvements on two components from the health-related quality-of-life questionnaire, and a decrease in plasma IL-8 levels after the intervention. The HBPR is an important and viable alternative to pulmonary rehabilitation for the treatment of patients with COPD; it improves exercise tolerance, inspiratory muscle strength, quality of life, and systemic inflammation in COPD patients.

Activity restriction in mild COPD: a challenging clinical problem

PubMed Central

O’Donnell, Denis E; Gebke, Kevin B

2014-01-01

Dyspnea, exercise intolerance, and activity restriction are already apparent in mild chronic obstructive pulmonary disease (COPD). However, patients may not seek medical help until their symptoms become troublesome and persistent and significant respiratory impairment is already present; as a consequence, further sustained physical inactivity may contribute to disease progression. Ventilatory and gas exchange impairment, cardiac dysfunction, and skeletal muscle dysfunction are present to a variable degree in patients with mild COPD, and collectively may contribute to exercise intolerance. As such, there is increasing interest in evaluating exercise tolerance and physical activity in symptomatic patients with COPD who have mild airway obstruction, as defined by spirometry. Simple questionnaires, eg, the modified British Medical Research Council dyspnea scale and the COPD Assessment Test, or exercise tests, eg, the 6-minute or incremental and endurance exercise tests can be used to assess exercise performance and functional status. Pedometers and accelerometers are used to evaluate physical activity, and endurance tests (cycle or treadmill) using constant work rate protocols are used to assess the effects of interventions such as pulmonary rehabilitation. In addition, alternative outcome measurements, such as tests of small airway dysfunction and laboratory-based exercise tests, are used to measure the extent of physiological impairment in individuals with persistent dyspnea. This review describes the mechanisms of exercise limitation in patients with mild COPD and the interventions that can potentially improve exercise tolerance. Also discussed are the benefits of pulmonary rehabilitation and the potential role of pharmacologic treatment in symptomatic patients with mild COPD. PMID:24940054

Critical Power: An Important Fatigue Threshold in Exercise Physiology

PubMed Central

Poole, David C.; Burnley, Mark; Vanhatalo, Anni; Rossiter, Harry B.; Jones, Andrew M.

2016-01-01

The hyperbolic form of the power-duration relationship is rigorous and highly conserved across species, forms of exercise and individual muscles/muscle groups. For modalities such as cycling, the relationship resolves to two parameters, the asymptote for power (critical power, CP) and the so-called W′ (work doable above CP), which together predict the tolerable duration of exercise above CP. Crucially, the CP concept integrates sentinel physiological profiles - respiratory, metabolic and contractile - within a coherent framework that has great scientific and practical utility. Rather than calibrating equivalent exercise intensities relative to metabolically distant parameters such as the lactate threshold or V̇O2 max, setting the exercise intensity relative to CP unifies the profile of systemic and intramuscular responses and, if greater than CP, predicts the tolerable duration of exercise until W′ is expended, V̇O2 max is attained, and intolerance is manifested. CP may be regarded as a ‘fatigue threshold’ in the sense that it separates exercise intensity domains within which the physiological responses to exercise can (CP) be stabilized. The CP concept therefore enables important insights into 1) the principal loci of fatigue development (central vs. peripheral) at different intensities of exercise, and 2) mechanisms of cardiovascular and metabolic control and their modulation by factors such as O2 delivery. Practically, the CP concept has great potential application in optimizing athletic training programs and performance as well as improving the life quality for individuals enduring chronic disease. PMID:27031742

Critical Power: An Important Fatigue Threshold in Exercise Physiology.

PubMed

Poole, David C; Burnley, Mark; Vanhatalo, Anni; Rossiter, Harry B; Jones, Andrew M

2016-11-01

: The hyperbolic form of the power-duration relationship is rigorous and highly conserved across species, forms of exercise, and individual muscles/muscle groups. For modalities such as cycling, the relationship resolves to two parameters, the asymptote for power (critical power [CP]) and the so-called W' (work doable above CP), which together predict the tolerable duration of exercise above CP. Crucially, the CP concept integrates sentinel physiological profiles-respiratory, metabolic, and contractile-within a coherent framework that has great scientific and practical utility. Rather than calibrating equivalent exercise intensities relative to metabolically distant parameters such as the lactate threshold or V˙O2max, setting the exercise intensity relative to CP unifies the profile of systemic and intramuscular responses and, if greater than CP, predicts the tolerable duration of exercise until W' is expended, V˙O2max is attained, and intolerance is manifested. CP may be regarded as a "fatigue threshold" in the sense that it separates exercise intensity domains within which the physiological responses to exercise can (CP) be stabilized. The CP concept therefore enables important insights into 1) the principal loci of fatigue development (central vs. peripheral) at different intensities of exercise and 2) mechanisms of cardiovascular and metabolic control and their modulation by factors such as O2 delivery. Practically, the CP concept has great potential application in optimizing athletic training programs and performance as well as improving the life quality for individuals enduring chronic disease.

Effects of combined exercise training and electromyostimulation treatments in chronic heart failure: A prospective multicentre study.

PubMed

Iliou, Marie C; Vergès-Patois, Bénédicte; Pavy, Bruno; Charles-Nelson, Anais; Monpère, Catherine; Richard, Rudy; Verdier, Jean C

2017-08-01

Background Exercise training as part of a comprehensive cardiac rehabilitation is recommended for patients with cardiac heart failure. It is a valuable method for the improvement of exercise tolerance. Some studies reported a similar improvement with quadricipital electrical myostimulation, but the effect of combined exercise training and electrical myostimulation in cardiac heart failure has not been yet evaluated in a large prospective multicentre study. Purpose The aim of this study was to determine whether the addition of low frequency electrical myostimulation to exercise training may improve exercise capacity and/or muscular strength in cardiac heart failure patients. Methods Ninety-one patients were included (mean age: 58 ± 9 years; New York Heart Association II/III: 52/48%, left ventricular ejection fraction: 30 ± 7%) in a prospective French study. The patients were randomised into two groups: 41 patients in exercise training and 50 in exercise training + electrical myostimulation. All patients underwent 20 exercise training sessions. In addition, in the exercise training + electrical myostimulation group, patients underwent 20 low frequency (10 Hz) quadricipital electrical myostimulation sessions. Each patient underwent a cardiopulmonary exercise test, a six-minute walk test, a muscular function evaluation and a quality of life questionnaire, before and at the end of the study. Results A significant improvement of exercise capacity (Δ peak oxygen uptake+15% in exercise training group and +14% in exercise training + electrical myostimulation group) and of quality of life was observed in both groups without statistically significant differences between the two groups. Mean creatine kinase level increased in the exercise training group whereas it remained stable in the combined group. Conclusions This prospective multicentre study shows that electrical myostimulation on top of exercise training does not demonstrate any significant additional improvement in exercise capacity in cardiac heart failure patients.

The Influence of Passive Acceleration and Exercise+Acceleration on Work Capacity and Orthostasis

NASA Technical Reports Server (NTRS)

Simonson, S. R.; Cowell, S. A.; Stocks, J. M.; Biagini, H. W.; Vener, J. M.; Evetts, S. N.; Bailey, K. N.; Evans, J.; Knapp, C.; Greenleaf, J. E.

1999-01-01

The losses of aerobic power and orthostatic tolerance are significant effects of manned C) spaceflight that can negatively impact crew health and safety. Daily acceleration and aerobic training may ameliorate these effects. To determine the influence of passive intermittent +Gz acceleration (PA) training and active acceleration + interval exercise (AE) training on work 0 0 capacity and the acute (1 min) response to 70 deg head-up tilt, 6 men (X-Bar SD: age, 33 +/- 6 y; height, 178.3 +/- 4.6 cm; mass, 86.3 +/- 6.6 kg) participated in two 3-wk training protocols. It was hypothesized that PA and AE training would improve orthostatic tolerance and that the addition of aerobic conditioning, would not alter this effect.

COPD and exercise: does it make a difference?

PubMed Central

Burtin, Chris; De Boever, Patrick; Langer, Daniël; Vogiatzis, Ioannis; Wouters, Emiel F.M.; Franssen, Frits M.E.

2016-01-01

Key points Physiological changes are observed following a structured exercise training programme in patients with COPD, without changes in resting lung function. Exercise training is the cornerstone of a comprehensive pulmonary rehabilitation programme in patients with COPD. Most comorbidities in patients referred for pulmonary rehabilitation remain undiagnosed and untreated. After careful screening, it is safe for COPD patients with comorbidities to obtain significant and clinically relevant improvements in functional exercise capacity and health status after an exercise-based pulmonary rehabilitation programme. Educational aims To inform readers of the positive effects of exercise-based pulmonary rehabilitation in patients with COPD, even with comorbid conditions. To inform readers of the importance of physical activity in patients with COPD. Exercise training is widely regarded as the cornerstone of pulmonary rehabilitation in patients with chronic obstructive pulmonary disease (COPD). Indeed, exercise training has been identified as the best available means of improving muscle function and exercise tolerance in patients with COPD. So, exercise training truly makes a difference in the life of patients with COPD. In this review, an overview is provided on the history of exercise training (as standalone intervention or as part of a comprehensive pulmonary rehabilitation programme), exercise training in comorbid patients with COPD, and the impact of physical activity counselling in a clean air environment. PMID:27408645

Cholinergic stimulation with pyridostigmine protects against exercise induced myocardial ischaemia

PubMed Central

Castro, R R T; Porphirio, G; Serra, S M; Nóbrega, A C L

2004-01-01

Objective: To determine the acute effects of pyridostigmine bromide, a reversible cholinesterase inhibitor, during exercise in patients with coronary artery disease. Design: Double blind, randomised, placebo controlled, crossover study. Setting: Outpatients evaluated in an exercise test laboratory. Patients: 15 patients with exercise induced myocardial ischaemia. Interventions: Maximal cardiopulmonary exercise test on a treadmill according to an individualised ramp protocol on three days. The first day was used for adaptation to the equipment and to determine exercise tolerance and the presence of exercise induced ischaemia. On the other two days, the cardiopulmonary exercise test was performed two hours after oral administration of pyridostigmine (45 mg) or placebo. All patients were taking their usual medication during the experiments. Main outcome measures: Rate–pressure product and oxygen uptake during exercise. Results: Pyridostigmine inhibited the submaximum chronotropic response (p  =  0.001), delaying the onset of myocardial ischaemia, which occurred at a similar rate–pressure product (mean (SE) placebo 20.55 (1.08) mm Hg × beats/min 103; pyridostigmine 19.75 (1.28) mm Hg × beats/min 103; p  =  0.27) but at a higher exercise intensity (oxygen consumption: placebo 18.6 (1.7) ml/kg/min; pyridostigmine 19.6 (1.8) ml/kg/min; p  =  0.03). Also, pyridostigmine increased peak oxygen consumption (placebo 23.6 (2) ml/kg/min; pyridostigmine 24.8 (2) ml/kg/min; p  =  0.01) and peak oxygen pulse (placebo 12.9 (1) ml/beat; pyridostigmine 13.6 (1) ml/beat; p  =  0.02). Conclusions: Pyridostigmine improved peak exercise tolerance and inhibited the chronotropic response to submaximum exercise, increasing the intensity at which myocardial ischaemia occurred. These results suggest that pyridostigmine can protect against exercise induced myocardial ischaemia. PMID:15367503

A Six-Month Randomized Controlled Trial of Exercise and Pyridostigmine in the Treatment of Fibromyalgia

PubMed Central

Jones, K. D.; Burckhardt, C. S.; Deodhar, A. A.; Perrin, N. A.; Hanson, G. C.; Bennett, R. M.

2008-01-01

Objective A subset of fibromyalgia (FM) patients have a dysfunctional hypothalamic–pituitary–insulin-like growth factor 1 (IGF-1) axis, as evidenced by low serum levels of IGF-1 and a reduced growth hormone (GH) response to physiologic stimuli. There is evidence that pyridostigmine (PYD) improves the acute response of GH to exercise in FM patients. The purpose of this study was to evaluate the clinical effectiveness of 6 months of PYD and group exercise on FM symptoms. Methods FM patients were randomized to 1 of the following 4 groups: PYD plus exercise, PYD plus diet recall but no exercise, placebo plus exercise, and placebo plus diet recall but no exercise. The primary outcome measures were the visual analog scale (VAS) score for pain, tender point count, and total myalgic score. Secondary outcome measures were the total score on the Fibromyalgia Impact Questionnaire (FIQ) and FIQ VAS scores for individual symptoms (fatigue, poor sleep, stiffness, and anxiety), as well as quality of life (QOL) and physical fitness (lower body strength/endurance, upper and lower body flexibility, balance, and time on the treadmill). Results A total of 165 FM patients completed baseline measurements; 154 (93.3%) completed the study. The combination of PYD and exercise did not improve pain scores. PYD groups showed a significant improvement in sleep and anxiety in those who completed the study and in QOL in those who complied with the therapeutic regimen as compared with the placebo groups. Compared with the nonexercise groups, the 2 exercise groups demonstrated improvement in fatigue and fitness. PYD was generally well tolerated. Conclusion Neither the combination of PYD plus supervised exercise nor either treatment alone yielded improvement in most FM symptoms. However, PYD did improve anxiety and sleep, and exercise improved fatigue and fitness. We speculate that PYD may have improved vagal tone, thus benefiting sleep and anxiety; this notion warrants further study. PMID:18240245

[Role of physical activity in the therapy and prevention of Type II diabetes mellitus].

PubMed

Lehmann, R; Spinas, G A

1996-12-01

Increased physical activity should be part of the treatment for non insulin-dependent diabetic patients. Increased physical activity delays the onset of non insulin-dependent diabetes mellitus (NIDDM) or even prevents the disease in about 50% of susceptible individuals (positive family history of NIDDM, body-mass index > 25, hypertension or gestational diabetes). Regular exercise has been shown to lower plasma triglyceride and to increase high-density lipoprotein cholesterol levels. Exercise has also beneficial effects on hypertension, body composition and fat distribution. Improved glucose tolerance has been achieved in type II diabetic patients in as little as one week with an exercise program. The beneficial effect of regular exercise on glucose control appears to reflect the cumulative effect of transient improvement in glucose tolerance following each individual bout of exercise. Increased insulin sensitivity is lost after as little as three days of inactivity. Most studies suggest that the maximum benefit from exercise is most likely to occur in patients with mild diabetes in whom insulin resistance and hyperinsulinemia are present (i.e. patients with fasting blood glucose of < 11 mM). The recommended frequency and duration of exercise is three times per week or every other day and, as adjunct for weight reduction, five to seven times per week for 30 to 45 min. at an intensity of 50 to 70% VO2max (or 60 to 80% of maximal the heart rate). Because of the high incidence of ischemic heart disease in type II diabetic patients, patients older than 35 years of age should undergo a graded exercise stress electrocardiogram. Attention should be paid to foot-care and the use of appropriate footwear and diabetic late complications, such as autonomic and peripheral neuropathy. Older obese NIDDM patients can achieve significant metabolic benefits from low-intensity programs, such as daily walking, which can be easily incorporated into daily living. Taking the necessary precautions, most patients with diabetes can take part in a monitored exercise program safely.

A Single Bout of Aerobic Exercise Reduces Anxiety Sensitivity But Not Intolerance of Uncertainty or Distress Tolerance: A Randomized Controlled Trial.

PubMed

LeBouthillier, Daniel M; Asmundson, Gordon J G

2015-01-01

Several mechanisms have been posited for the anxiolytic effects of exercise, including reductions in anxiety sensitivity through interoceptive exposure. Studies on aerobic exercise lend support to this hypothesis; however, research investigating aerobic exercise in comparison to placebo, the dose-response relationship between aerobic exercise anxiety sensitivity, the efficacy of aerobic exercise on the spectrum of anxiety sensitivity and the effect of aerobic exercise on other related constructs (e.g. intolerance of uncertainty, distress tolerance) is lacking. We explored reductions in anxiety sensitivity and related constructs following a single session of exercise in a community sample using a randomized controlled trial design. Forty-one participants completed 30 min of aerobic exercise or a placebo stretching control. Anxiety sensitivity, intolerance of uncertainty and distress tolerance were measured at baseline, post-intervention and 3-day and 7-day follow-ups. Individuals in the aerobic exercise group, but not the control group, experienced significant reductions with moderate effect sizes in all dimensions of anxiety sensitivity. Intolerance of uncertainty and distress tolerance remained unchanged in both groups. Our trial supports the efficacy of aerobic exercise in uniquely reducing anxiety sensitivity in individuals with varying levels of the trait and highlights the importance of empirically validating the use of aerobic exercise to address specific mental health vulnerabilities. Aerobic exercise may have potential as a temporary substitute for psychotherapy aimed at reducing anxiety-related psychopathology.

Obesity and metabolic syndrome in COPD: Is exercise the answer?

PubMed

James, Benjamin D; Jones, Amy V; Trethewey, Ruth E; Evans, Rachael A

2018-05-01

Approximately half of all patients with chronic obstructive pulmonary disease (COPD) attending pulmonary rehabilitation (PR) programmes are overweight or obese which negatively impacts upon dyspnoea and exercise tolerance particularly when walking. Within the obese population (without COPD), the observed heterogeneity in prognosis is in part explained by the variability in the risk of developing cardiovascular disease or diabetes (cardiometabolic risk) leading to the description of metabolic syndrome. In obesity alone, high-intensity aerobic training can support healthy weight loss and improve the constituent components of metabolic syndrome. Those with COPD, obesity and/or metabolic syndrome undergoing PR appear to do as well in traditional outcomes as their normal-weight metabolically healthy peers in terms of improvement of symptoms, health-related quality of life and exercise performance, and should therefore not be excluded. To broaden the benefit of PR, for this complex population, we should learn from the extensive literature examining the effects of exercise in obesity and metabolic syndrome discussed in this review and optimize the exercise strategy to improve these co-morbid conditions. Standard PR outcomes could be expanded to include cardiometabolic risk reduction to lower future morbidity and mortality; to this end exercise may well be the answer.

Obesity and metabolic syndrome in COPD: Is exercise the answer?

PubMed Central

James, Benjamin D; Jones, Amy V; Trethewey, Ruth E; Evans, Rachael A

2017-01-01

Approximately half of all patients with chronic obstructive pulmonary disease (COPD) attending pulmonary rehabilitation (PR) programmes are overweight or obese which negatively impacts upon dyspnoea and exercise tolerance particularly when walking. Within the obese population (without COPD), the observed heterogeneity in prognosis is in part explained by the variability in the risk of developing cardiovascular disease or diabetes (cardiometabolic risk) leading to the description of metabolic syndrome. In obesity alone, high-intensity aerobic training can support healthy weight loss and improve the constituent components of metabolic syndrome. Those with COPD, obesity and/or metabolic syndrome undergoing PR appear to do as well in traditional outcomes as their normal-weight metabolically healthy peers in terms of improvement of symptoms, health-related quality of life and exercise performance, and should therefore not be excluded. To broaden the benefit of PR, for this complex population, we should learn from the extensive literature examining the effects of exercise in obesity and metabolic syndrome discussed in this review and optimize the exercise strategy to improve these co-morbid conditions. Standard PR outcomes could be expanded to include cardiometabolic risk reduction to lower future morbidity and mortality; to this end exercise may well be the answer. PMID:29117797

Growth hormone-insulin-like growth factor-1 and inflammatory response to a single exercise bout in children and adolescents.

PubMed

Nemet, Dan; Eliakim, Alon

2010-01-01

Physical activity plays an important role in tissue anabolism, growth and development, but the mechanisms that link patterns of exercise with tissue anabolism are not completely understood. The effectiveness of physical training depends on the training load and on the individual ability to tolerate it, and an imbalance between the two may lead to under or over-training. Therefore, many efforts have been made to find objective parameters to quantify the balance between training load and the athlete's tolerance. One of the unique features of exercise is that it leads to a simultaneous increase of antagonistic mediators. On the one hand, exercise stimulates anabolic components of the growth hormone (GH) → IGF-1 (insulin-like growth factor-1) axis. On the other hand, exercise elevates catabolic pro-inflammatory cytokines such as interleukin-6 (IL-6), IL-1 and tumor necrosis factor-α (TNF-α). This emphasizes probably the importance of optimal adaptation to exercise in particularly during adolescence. The very fine balance between the anabolic and inflammatory/catabolic response to exercise will determine the effectiveness of exercise training and the health consequences of exercise. If the anabolic response is stronger, exercise will probably lead ultimately to increased muscle mass and improved fitness. A greater catabolic response, in particularly if persists for long duration, may lead to overtraining. Therefore, changes in the anabolic-catabolic hormonal balance and in circulating inflammatory cytokines can be used by adolescent athletes and/or their coaches to gauge the training intensity in individual and team sports. Copyright © 2010 S. Karger AG, Basel.

Treadmill Exercise Within LBNP as an Integrated Coutermeasure to Microgravity

NASA Technical Reports Server (NTRS)

Lee, Stuart; Hargens, A. R.; Schneider, S. M.; Watenpaugh, D. E.

2010-01-01

An integrated exercise countermeasure for microgravity is needed to protect multiple physiologic systems and save crew time. Such a countermeasure should protect orthostatic tolerance, upright ambulatory capability (including sprinting), aerobic capacity, muscle strength/endurance, and other physiologic parameters relevant to human performance. We developed a novel physiologic countermeasure, treadmill exercise within LBNP, for preventing cardiovascular and musculoskeletal deconditioning associated with prolonged bed rest and spaceflight. We evaluated 40 min of daily LBNP treadmill exercise by a battery of physiologic parameters relevant to maintaining exercise performance and health of both women and men during bed-rest (simulated microgravity) studies lasting from 5 to 60 days. For 30 day studies, we employed identical twins with one twin as the control and the other twin as the exerciser to improve comparative power. During the WISE 60-day HDT study, the treadmill exercise within LBNP was performed 3-4 days each week and resistive exercise was performed 2-3 days each week. Our treadmill within LBNP protocol maintained plasma volume and sprint speed (30 day HDT bed-rest studies of identical twins), orthostatic tolerance to a degree, upright exercise capacity, muscle strength and endurance, and some bone parameters during 30 day (twin studies) and 60 day (WISE-2005) bed-rest simulations of microgravity. When combining treadmill exercise within LBNP and resistive exercise (WISE), cardiac mass increased significantly in the exercise (EX) group during bed rest relative to controls (CON). Upright peak VO2, and knee extensor strength and endurance decreased significantly in CON subjects; but these parameters were preserved in the EX group. In the 60 day WISE study, each LBNP exercise session was followed immediately by 10 minutes of static LBNP, and the last such session occurred three days before the end of bed rest. Still, orthostatic tolerance was better maintained in the EX group than in the CON group. Therefore, these collective peer-reviewed results document that our treadmill exercise within LBNP countermeasure safely and efficiently protects multiple physiologic systems in women and men during bed-rest studies of up to 60 days. Supported by NASA grants NNJ04HF71G and NAG 9-1425, NIH grant GCRC M01 RR00827 and by WISE support from ESA, NASA, CSA, and CNES.

Baroreflex responses and LBNP tolerance following exercise training

NASA Technical Reports Server (NTRS)

Convertino, V. A.; Thompson, C. A.; Eckberg, D. L.; Fritsch, J. M.; Mack, G. W.; Nadel, E. R.

1990-01-01

The hypothesis that endurance exercise training designed to increase aerobic capacity results in reduced orthostatic tolerance due to alterations of blood-pressure controlling mechanisms was reexamined using a specially designed training in which tolerance to orthostasis and the primary mechanisms associated with the blood-pressure control could be measured before and after the increase in aerobic capacity. Results demonstrate that maximal oxygen uptake can be significantly elevated in individuals of average fit without reducing lower body negative pressure tolerance. The exercise training was found to cause a resting bradycardia, which had no effect on the cardiac vagal reflex response.

Non-invasive ventilation (NIV) as an aid to rehabilitation in acute respiratory disease.

PubMed

Dyer, Fran; Flude, Lizzie; Bazari, Farid; Jolley, Caroline; Englebretsen, Catherine; Lai, Dilys; Polkey, Michael I; Hopkinson, Nicholas S

2011-12-16

Non-invasive ventilation (NIV) can increase exercise tolerance, reduce exercise induced desaturation and improve the outcome of pulmonary rehabilitation in patients with chronic respiratory disease. It is not known whether it can be applied to increase exercise capacity in patients admitted with non-hypercapnic acute exacerbations of COPD (AECOPD). We investigated the acceptability and feasibility of using NIV for this purpose. On a single occasion, patients admitted with an acute exacerbation of chronic respiratory disease who were unable to cycle for five minutes at 20 watts attempted to cycle using NIV and their endurance time (T(lim)) was recorded. To determine feasibility of this approach in clinical practice patients admitted with AECOPD were screened for participation in a trial of regular NIV assisted rehabilitation during their hospital admission. In 12 patients tested on a single occasion NIV increased T(lim) from 184(65) seconds to 331(229) seconds (p = 0.04) and patients desaturated less (median difference = 3.5%, p = 0.029). In the second study, 60 patients were admitted to hospital during a three month period of whom only 18(30)% were eligible to participate and of these patients, only four (7%) consented to participate. NIV improves exercise tolerance in patients with acute exacerbations of chronic respiratory disease but the applicability of this approach in routine clinical practice may be limited. http://www.controlled-trials.com/ISRCTN35692743.

Mobile-phone-based home exercise training program decreases systemic inflammation in COPD: a pilot study.

PubMed

Wang, Chun-Hua; Chou, Pai-Chien; Joa, Wen-Ching; Chen, Li-Fei; Sheng, Te-Fang; Ho, Shu-Chuan; Lin, Horng-Chyuan; Huang, Chien-Da; Chung, Fu-Tsai; Chung, Kian Fan; Kuo, Han-Pin

2014-08-30

Moderate-intensity exercise training improves skeletal muscle aerobic capacity and increased oxidative enzyme activity, as well as exercise tolerance in COPD patients. To investigate whether the home-based exercise training program can reduce inflammatory biomarkers in patients with COPD, twelve patients using mobile phone assistance and 14 with free walk were assessed by incremental shuttle walk test (ISWT), spirometry, strength of limb muscles, and serum C-reactive protein (CRP) and inflammatory cytokines. Patients in the mobile phone group improved their ISWT walking distance, with decrease in serum CRP after 2 months, and sustained at 6 months. Patients in the control group had no improvement. Serum IL-8 in the mobile phone group was significantly reduced at 2, 3 and 6 months after doing home exercise training compared to baseline. IL-6 and TNF-α were significantly elevated at 3 and 6 months in control group, while there were no changes in mobile phone group. The strength of limb muscles was significantly greater compared to baseline at 3 and 6 months in the mobile phone group. A mobile-phone-based system can provide an efficient home endurance exercise training program with improved exercise capacity, strength of limb muscles and a decrease in serum CRP and IL-8 in COPD patients. Decreased systemic inflammation may contribute to these clinical benefits. (Clinical trial registration No.: NCT01631019).

Cardiovascular response to exercise training in the systemic right ventricle of adults with transposition of the great arteries

PubMed Central

Shafer, K M; Janssen, L; Carrick-Ranson, G; Rahmani, S; Palmer, D; Fujimoto, N; Livingston, S; Matulevicius, S A; Forbess, L W; Brickner, B; Levine, B D

2015-01-01

We aimed to assess the haemodynamic effects of exercise training in transposition of the great arteries (TGA) patients with systemic right ventricles (SRVs). TGA patients have limited exercise tolerance and early mortality due to systemic (right) ventricular failure. Whether exercise training enhances or injures the SRV is unclear. Fourteen asymptomatic patients (34 ± 10 years) with TGA and SRV were enrolled in a 12 week exercise training programme (moderate and high-intensity workouts). Controls were matched on age, gender, BMI and physical activity. Exercise testing pre- and post- training included: (a) submaximal and peak; (b) prolonged (60 min) submaximal endurance and (c) high-intensity intervals. Oxygen uptake (; Douglas bag technique), cardiac output (, foreign-gas rebreathing), ventricular function (echocardiography and cardiac MRI) and serum biomarkers were assessed. TGA patients had lower peak , , and stroke volume (SV), a blunted / slope, and diminished SV response to exercise (SV increase from rest: TGA = 15.2%, controls = 68.9%, P < 0.001) compared with controls. After training, TGA patients increased peak by 6 ± 8.5%, similar to controls (interaction P = 0.24). The magnitude of SV reserve on initial testing correlated with training response (r = 0.58, P = 0.047), though overall, no change in peak was observed. High-sensitivity troponin T (hs-TnT) and N-terminal prohormone of brain naturetic peptide (NT pro-BNP) were low and did not change with acute exercise or after training. Our data show that TGA patients with SRVs in this study safely participated in exercise training and improved peak . Neither prolonged submaximal exercise, nor high-intensity intervals, nor short-term exercise training seem to injure the systemic right ventricle. Key Points Patients with transposition of the great arteries (TGA) and systemic right ventricles have premature congestive heart failure; there is also a growing concern that athletes who perform extraordinary endurance exercise may injure the right ventricle. Therefore we felt it essential to determine whether exercise training might injure a systemic right ventricle which is loaded with every heartbeat. Previous studies have shown that short term exercise training is feasible in TGA patients, but its effect on ventricular function is unclear. We demonstrate that systemic right ventricular function is preserved (and may be improved) in TGA patients with exercise training programmes that are typical of recreational and sports participation, with no evidence of injury on biomarker assessment. Stroke volume reserve during exercise correlates with exercise training response in our TGA patients, identifying this as a marker of a systemic right ventricle (SRV) that may most tolerate (and possibly even be improved by) exercise training. PMID:25809342

Perinatal exercise improves glucose homeostasis in adult offspring

PubMed Central

Carter, Lindsay G.; Lewis, Kaitlyn N.; Wilkerson, Donald C.; Tobia, Christine M.; Ngo Tenlep, Sara Y.; Shridas, Preetha; Garcia-Cazarin, Mary L.; Wolff, Gretchen; Andrade, Francisco H.; Charnigo, Richard J.; Esser, Karyn A.; Egan, Josephine M.; de Cabo, Rafael

2012-01-01

Emerging research has shown that subtle factors during pregnancy and gestation can influence long-term health in offspring. In an attempt to be proactive, we set out to explore whether a nonpharmacological intervention, perinatal exercise, might improve offspring health. Female mice were separated into sedentary or exercise cohorts, with the exercise cohort having voluntary access to a running wheel prior to mating and during pregnancy and nursing. Offspring were weaned, and analyses were performed on the mature offspring that did not have access to running wheels during any portion of their lives. Perinatal exercise caused improved glucose disposal following an oral glucose challenge in both female and male adult offspring (P < 0.05 for both). Blood glucose concentrations were reduced to lower values in response to an intraperitoneal insulin tolerance test for both female and male adult offspring of parents with access to running wheels (P < 0.05 and P < 0.01, respectively). Male offspring from exercised dams showed increased percent lean mass and decreased fat mass percent compared with male offspring from sedentary dams (P < 0.01 for both), but these parameters were unchanged in female offspring. These data suggest that short-term maternal voluntary exercise prior to and during healthy pregnancy and nursing can enhance long-term glucose homeostasis in offspring. PMID:22932781

Exercise training decreases pancreatic fat content and improves beta cell function regardless of baseline glucose tolerance: a randomised controlled trial.

PubMed

Heiskanen, Marja A; Motiani, Kumail K; Mari, Andrea; Saunavaara, Virva; Eskelinen, Jari-Joonas; Virtanen, Kirsi A; Koivumäki, Mikko; Löyttyniemi, Eliisa; Nuutila, Pirjo; Kalliokoski, Kari K; Hannukainen, Jarna C

2018-05-02

Pancreatic fat accumulation may contribute to the development of beta cell dysfunction. Exercise training improves whole-body insulin sensitivity, but its effects on pancreatic fat content and beta cell dysfunction are unclear. The aim of this parallel-group randomised controlled trial was to evaluate the effects of exercise training on pancreatic fat and beta cell function in healthy and prediabetic or type 2 diabetic participants and to test whether the responses were similar regardless of baseline glucose tolerance. Using newspaper announcements, a total of 97 sedentary 40-55-year-old individuals were assessed for eligibility. Prediabetes (impaired fasting glucose and/or impaired glucose tolerance) and type 2 diabetes were defined by ADA criteria. Of the screened candidates, 28 healthy men and 26 prediabetic or type 2 diabetic men and women met the inclusion criteria and were randomised into 2-week-long sprint interval or moderate-intensity continuous training programmes in a 1:1 allocation ratio using random permuted blocks. The primary outcome was pancreatic fat, which was measured by magnetic resonance spectroscopy. As secondary outcomes, beta cell function was studied using variables derived from OGTT, and whole-body insulin sensitivity and pancreatic fatty acid and glucose uptake were measured using positron emission tomography. The measurements were carried out at the Turku PET Centre, Finland. The analyses were based on an intention-to-treat principle. Given the nature of the intervention, blinding was not applicable. At baseline, the group of prediabetic or type 2 diabetic men had a higher pancreatic fat content and impaired beta cell function compared with the healthy men, while glucose and fatty acid uptake into the pancreas was similar. Exercise training decreased pancreatic fat similarly in healthy (from 4.4% [3.0%, 6.1%] to 3.6% [2.4%, 5.2%] [mean, 95% CI]) and prediabetic or type 2 diabetic men (from 8.7% [6.0%, 11.9%] to 6.7% [4.4%, 9.6%]; p = 0.036 for time effect) without any changes in pancreatic substrate uptake (p ≥ 0.31 for time effect in both insulin-stimulated glucose and fasting state fatty acid uptake). In prediabetic or type 2 diabetic men and women, both exercise modes similarly improved variables describing beta cell function. Two weeks of exercise training improves beta cell function in prediabetic or type 2 diabetic individuals and decreases pancreatic fat regardless of baseline glucose tolerance. This study shows that short-term training efficiently reduces ectopic fat within the pancreas, and exercise training may therefore reduce the risk of type 2 diabetes. ClinicalTrials.gov NCT01344928 FUNDING: This study was funded by the Emil Aaltonen Foundation, the European Foundation for the Study of Diabetes, the Finnish Diabetes Foundation, the Orion Research Foundation, the Academy of Finland (grants 251399, 256470, 281440, and 283319), the Ministry of Education of the State of Finland, the Paavo Nurmi Foundation, the Novo Nordisk Foundation, the Finnish Cultural Foundation, the Hospital District of Southwest Finland, the Turku University Foundation, and the Finnish Medical Foundation.

Cardiovascular adaptations in weightlessness: The influence of in-flight exercise programs on the cardiovascular adjustments during weightlessness and upon returning to Earth

NASA Technical Reports Server (NTRS)

Bennett, C. H.

1981-01-01

The effect of in-flight exercise programs on astronauts' cardiovascular adjustments during spaceflight weightlessness and upon return to Earth was studied. Physiological changes in muscle strength and volume, cardiovascular responses during the application of lower body negative pressure, and metabolic activities during pre-flight and flight tests were made on Skylab crewmembers. The successful completion of the Skylab missions showed that man can perform submaximal and maximal aerobic exercise in the weightless enviroment without detrimental trends in any of the physiologic data. Exercise tolerance during flight was unaffected. It was only after return to Earth that a tolerance decrement was noted. The rapid postflight recovery of orthostatic and exercise tolerance following two of the three Skylab missions appeared to be directly related to total in-flight exercise as well as to the graded, regular program of exercise performed during the postflight debriefing period.

Trimetazidine improves exercise tolerance in patients with ischemic heart disease : A meta-analysis.

PubMed

Zhao, Y; Peng, L; Luo, Y; Li, S; Zheng, Z; Dong, R; Zhu, J; Liu, J

2016-09-01

This study aimed to evaluate the effect of trimetazidine (TMZ) in addition to standard treatment on exercise tolerance in patients with ischemic heart disease (IHD). Studies were identified via a systematic search of PubMed, Embase, Cochrane Library, and the Chinese CNKI databases from January 1978 to January 2015. Data extraction, synthesis, and statistical analysis were performed by standard meta-analysis methods. Random or fixed effects models were used to estimate pooled mean differences in total exercise duration (TED), peak oxygen uptake (pVO2), metabolic equivalent system (METS), and 6-minute walking test (6-MWT). In all, 16 randomized controlled trials (RCTs) consisting of 2,004 participants were included. Pooled results showed that TMZ treatment significantly improved TED (WMD: 37.35, 95 % CI: 25.58-49.13, p < 0.00001), pVO2 (WMD: 2.41, 95 % CI: 1.76-3.06, p < 0.00001), METS (WMD: 1.33, 95 % CI: 0.38-2.28, p = 0.006), and 6-WMT (WMD: 62.46, 95 % CI: 35.86-89.05, p < 0.001) in all patients with IHD. Subgroup analysis showed that TMZ significantly increased TED in nondiabetic participants (WMD 34.77, 95 % CI: 22.28-47.25, p < 0.001), but not in diabetic participants (WMD: 40.36, 95 % CI: - 18.76-99.48, p = 0.18). And, subgroup analysis of TED by intervention duration suggested that there is no statistically difference between the 3-month and 6-month periods (WMD: 35.47, 95 %CI: 18.35-52.60, p < 0.0001 and WMD: 49.94, 95 %CI: 44.69-55.19, p < 0.00001). In addition, TMZ improved TED (WMD: 50.01, 95 % CI: 44.77-55.25 and WMD: 24.20, 95 % CI: 12.72-35.68) in IHD patients with or without heart failure (HF), respectively. Addition of TMZ to standard treatment significantly improved exercise tolerance in patients with IHD, and IHD patients with HF may experience even more benefits. However, there is insufficient evidence to show that TMZ has beneficial effects in participants with diabetes.

Differences in change in coping styles between good responders, moderate responders and non-responders to pulmonary rehabilitation.

PubMed

Stoilkova-Hartmann, Ana; Janssen, Daisy J A; Franssen, Frits M E; Wouters, Emiel F M

2015-12-01

Pulmonary rehabilitation (PR) improves exercise tolerance and health status in patients with chronic obstructive pulmonary disease (COPD). Data on the effects of PR on coping styles are limited. Aim of the present study was to compare changes in coping styles between patients who had a good, moderate and no improvement in either exercise tolerance or health status after PR. Coping styles of 439 COPD patients undergoing PR were assessed by the Utrecht Coping List (UCL) at baseline and after PR. Patients' pulmonary function, six-minute walking distance (6MWD), St. George's Respiratory Questionnaire (SGRQ) and Hospital Anxiety and Depression Scale (HADS-A and HADS-D) were recorded. Good, moderate and non-responders were defined on the basis of minimally clinically important difference (MCID) for SGRQ total score and/or 6MWD. Overall, 54.0% of the patients fulfilled the criteria for good responders, while 22.1% were moderate responders. Change in passive reaction pattern coping style differed significantly between good responders and non-responders following PR (p < 0.001). Moreover, within the groups, changes in coping styles after PR occurred among the good responders, whereas the majority of moderate responders' and non-responders' coping styles were not significantly influenced by PR. Good responders decreased their passive reaction pattern coping style in contrast to non-responders after PR. In general, PR did not change the coping among moderate and non-responders. Further research is warranted to determine whether including interventions targeting coping styles may modify coping behaviour of COPD patients, as well as improvement in exercise tolerance or health status after PR. Copyright © 2015 Elsevier Ltd. All rights reserved.

Hydrotherapy added to endurance training versus endurance training alone in elderly patients with chronic heart failure: a randomized pilot study.

PubMed

Caminiti, Giuseppe; Volterrani, Maurizio; Marazzi, Giuseppe; Cerrito, Anna; Massaro, Rosalba; Sposato, Barbara; Arisi, Arianna; Rosano, Giuseppe

2011-04-14

To assess if Hydrotherapy (HT) added to endurance training (ET) is more effective than ET alone in order to improve exercise tolerance of elderly male patients with chronic heart failure (CHF). Twenty-one male CHF patients, age 68+/-7 (mean+/-DS) years; ejection fraction 32+/-9. NYHA II-III were enrolled. Eleven pts were randomized to combined training (CT) group performing HT+ET and 10 patients to ET group (ET only). At baseline and after 24 weeks all patients underwent: 6-minute walking test (6MWT), assessment of quadriceps maximal voluntary contraction (MVC) and peak torque (PT), blood pressure and heart rate (HR), echocardiography and non-invasive hemodynamic evaluation. HT was performed 3 times/week in upright position at up to the xyphoid process at a temperature of 31°C. ET was performed 3 times/week. Exercise was well tolerated. No patients had adverse events. Distance at 6MWT improved in both groups (CT group: 150+/-32 m; ET group:105+/-28 m) with significant intergroup differences (p 0.001). On land diastolic BP and HR significantly decreased in the CT group while remained unchanged in the ET group (-11 mmHg+/-2, p 0.04; e - 12 bpm, p 0.03; respectively) CO and SV had a relative despite no significant increase in CT group TPR on land significantly decreased in CT group (-23+/-3 mmHg/l/m; p 0.01) while remained unchanged in ET group. Patients of CT group had no significant higher increase of both MVC and PT than ET group. CT training, significantly improves exercise tolerance and hemodynamic profile of patients with CHF. Copyright © 2009 Elsevier Ireland Ltd. All rights reserved.

Serum Tumor Necrosis Factor-alpha associates with Myocardial Oxygen Demand and Exercise Tolerance in Postmenopausal Women.

PubMed

Carter, Stephen J; Bryan, David R; Neumeier, William H; Glasser, Stephen P; Hunter, Gary R

2018-01-01

The functional implications of serum tumor necrosis factor-alpha (TNF-α), a marker of oxidative stress, on hemodynamic parameters at rest and during physical exertion are unclear. The aims of this investigation were to examine the independent associations of TNF-α on myocardial oxygen demand at rest and during submaximal exercise, while also evaluating the association of TNF-α on exercise tolerance. Forty, postmenopausal women, provided blood samples and completed a modified-Balke protocol to measure maximal oxygen uptake (VO 2max ). Large artery compliance was measured by pulse contour analyses while rate-pressure product (RPP), an index of myocardial oxygen demand, was measured at rest and during two submaximal workloads (i.e., ≈55% and ≈75% VO 2max ). RPP was calculated by dividing the product of heart rate and systolic blood pressure (via auscultation) by 100. Exercise tolerance corresponded with the cessation of the graded exercise test. During higher-intensity exertion, ≈75% VO 2max , multiple linear regression revealed a positive association ( r = 0.43; p = 0.015) between TNF-α and RPP while adjusting for maximal heart rate, VO 2max , large artery compliance, and percent body fat. Path analyses revealed a significant indirect effect of large artery compliance on exercise tolerance through TNF-α, β = 0.13, CI [0.03, 0.35], indicating greater levels of TNF-α associated with poorer exercise tolerance. These data suggest TNF-α independently associates with myocardial oxygen demand during physical exertion, thus highlighting the utility of higher-intensity efforts to expose important phenomena not apparent at rest. TNF-α also appears to be indirectly associated with the link between large artery compliance and exercise tolerance.

Importance of Lean Muscle Maintenance to Improve Insulin Resistance by Body Weight Reduction in Female Patients with Obesity.

PubMed

Fukushima, Yaeko; Kurose, Satoshi; Shinno, Hiromi; Cao Thu, Ha; Takao, Nana; Tsutsumi, Hiromi; Kimura, Yutaka

2016-04-01

It has recently been suggested that skeletal muscle has an important role in insulin resistance in obesity, in addition to exercise tolerance and the fat index. The aim of this study was to identify body composition factors that contribute to improvement of insulin resistance in female patients with obesity who reduce body weight. We studied 92 female obese patients (age 40.9±10.4 years, body mass index 33.2±4.6 kg/m²) who reduced body weight by ≥5% after an intervention program including diet, exercise therapy, and cognitive behavioral therapy. Before and after the intervention, body composition was evaluated by dual-energy X-ray absorptiometry to examine changes in skeletal muscle mass. Homeostasis model assessment of insulin resistance (HOMA-IR) was measured as an index of insulin resistance. Cardiopulmonary exercise was also performed by all patients. There were significant improvements in body weight (-10.3%±4.5%), exercise tolerance (anaerobic threshold oxygen uptake 9.1%±18.4%, peak oxygen uptake 11.0%±14.2%), and HOMA-IR (-20.2%±38.3%). Regarding body composition, there were significant decreases in total body fat (-19.3%±9.6%), total fat-free mass (-2.7%±4.3%), and % body fat (-10.1%±7.5%), whereas % skeletal muscle significantly increased (8.9%±7.2%). In stepwise multiple linear regression analysis with change in HOMA-IR as the dependent variable, the change in % skeletal muscle was identified as an independent predictor (β=-0.280, R²=0.068, P<0.01). Improvement of insulin resistance in female obese patients requires maintenance of skeletal muscle mass.

Parasympathetic reinnervation accompanied by improved post-exercise heart rate recovery and quality of life in heart transplant recipients.

PubMed

Imamura, Teruhiko; Kinugawa, Koichiro; Okada, Ikuko; Kato, Naoko; Fujino, Takeo; Inaba, Toshiro; Maki, Hisataka; Hatano, Masaru; Kinoshita, Osamu; Nawata, Kan; Kyo, Shunei; Ono, Minoru

2015-01-01

Although sympathetic reinnervation is accompanied by the improvement of exercise tolerability during the first years after heart transplantation (HTx), little is known about parasympathetic reinnervation and its clinical impact. We enrolled 21 recipients (40 ± 16 years, 71% male) who had received successive cardiopulmonary exercise testing at 6 months, and 1 and 2 years after HTx. Exercise parameters such as peak oxygen consumption or achieved maximum load remained unchanged, whereas recovery parameters including heart rate (HR) recovery during 2 minutes and the delay of peak HR, which are influenced by parasympathetic activity, improved significantly during post-HTx 2 years (P < 0.05 for both). HR variability was analysed at post-HTx 6 months in 18 recipients, and high frequency power, representing parasympathetic activity, was significantly associated with the 2 recovery parameters (P < 0.05 for all). We also assessed quality of life using the Minnesota Living with Heart Failure (HF) Questionnaire at post-HTx 6 months and 2 years in the same 18 recipients, and those with improved recovery parameters enjoyed a better HF-specific quality of life (P < 0.05 for both). In conclusion, parasympathetic reinnervation emerges along with improved post-exercise recovery ability of HR and quality of life during post-HTx 2 years.

Exercise capacity in the Bidirectional Glenn physiology: Coupling cardiac index, ventricular function and oxygen extraction ratio.

PubMed

Vallecilla, Carolina; Khiabani, Reza H; Trusty, Phillip; Sandoval, Néstor; Fogel, Mark; Briceño, Juan Carlos; Yoganathan, Ajit P

2015-07-16

In Bi-directional Glenn (BDG) physiology, the superior systemic circulation and pulmonary circulation are in series. Consequently, only blood from the superior vena cava is oxygenated in the lungs. Oxygenated blood then travels to the ventricle where it is mixed with blood returning from the lower body. Therefore, incremental changes in oxygen extraction ratio (OER) could compromise exercise tolerance. In this study, the effect of exercise on the hemodynamic and ventricular performance of BDG physiology was investigated using clinical patient data as inputs for a lumped parameter model coupled with oxygenation equations. Changes in cardiac index, Qp/Qs, systemic pressure, oxygen extraction ratio and ventricular/vascular coupling ratio were calculated for three different exercise levels. The patient cohort (n=29) was sub-grouped by age and pulmonary vascular resistance (PVR) at rest. It was observed that the changes in exercise tolerance are significant in both comparisons, but most significant when sub-grouped by PVR at rest. Results showed that patients over 2 years old with high PVR are above or close to the upper tolerable limit of OER (0.32) at baseline. Patients with high PVR at rest had very poor exercise tolerance while patients with low PVR at rest could tolerate low exercise conditions. In general, ventricular function of SV patients is too poor to increase CI and fulfill exercise requirements. The presented mathematical model provides a framework to estimate the hemodynamic performance of BDG patients at different exercise levels according to patient specific data. Published by Elsevier Ltd.

Nutritional state and lung disease in cystic fibrosis.

PubMed

Bakker, W

1992-10-01

The life expectancy of patients with cystic fibrosis (CF) is largely dependent on the severity and progress of the pulmonary involvement associated with the disease. Many data support the view that malnutrition and deterioration of lung function are closely interrelated and interdependent, with each affecting the other, leading to a spiral decline in both. The occurrence of malnutrition appears to be associated with poor lung function and poor survival, and conversely prevention of malnutrition appears to be associated with better lung function and improved survival. Nutritional intervention may lead to an improvement in body weight, lung function and exercise tolerance, provided that the intervention is combined with exercise training in order to increase both respiratory and other muscle mass. These improvements can be preserved when patients have the stamina to continue with a high-energy, high-fat diet and daily exercise training at home.

Effect of Bronchodilation and Exercise Training with Behavior Modification on Exercise Tolerance and Downstream Effects on Symptoms and Physical Activity in COPD.

PubMed

Troosters, Thierry; Maltais, François; Leidy, Nancy; Lavoie, Kim L; Sedeno, Maria; Janssens, Wim; Garcia-Aymerich, Judith; Erzen, Damijan; De Sousa, Dorothy; Korducki, Lawrence; Hamilton, Alan; Bourbeau, Jean

2018-04-17

Bronchodilation and exercise training (ExT) improve exercise tolerance in patients with chronic obstructive pulmonary disease (COPD); however, behavior modification is required to impact on daily physical activity (PA). To assess whether tiotropium/olodaterol, ±ExT, would improve exercise endurance time (EET) and PA compared with placebo in patients participating in a self-management behavior-modification (SMBM) program. A 12-week, randomized, partially double-blind, placebo-controlled, parallel-group trial in patients with COPD (PHYSACTO®; NCT02085161). All patients were enrolled into SMBM and randomized 1:1:1:1 to once-daily placebo, tiotropium 5 µg, tiotropium/olodaterol 5/5 µg, or tiotropium/olodaterol 5/5 µg plus 8 weeks ExT. EET, measured by endurance shuttle walk test after 8 weeks, was the primary endpoint. Additional endpoints assessed downstream effects on PA (measured via accelerometry), and activity-related dyspnea and difficulty (using validated patient-reported questionnaires). SMBM + tiotropium/olodaterol, ±ExT, significantly improved EET at Week 8 versus SMBM + placebo (treatment ratio versus placebo: with ExT 1.46 [95% CI: 1.20, 1.78]; P=0.0002; without ExT 1.29 [1.06, 1.57]; P=0.0109). No significant increases in steps per day from baseline were observed over SMBM + placebo at Week 12 (increase of 1,098) when other therapies were added. Adding tiotropium/olodaterol, ±ExT, to SMBM reduced activity-related dyspnea versus placebo, while adding tiotropium/olodaterol + ExT reduced activity-related difficulty. Tiotropium/olodaterol, ±ExT, improved EET in patients with COPD taking part in an SMBM program. Combination bronchodilation, ±ExT, did not provide additional increases in objective PA compared with SMBM alone, but did reduce physical activity-related dyspnea and difficulty. Clinical trial registration available at www.clinicaltrials.gov, ID NCT02085161.

Intradialytic aerobic cycling exercise alleviates inflammation and improves endothelial progenitor cell count and bone density in hemodialysis patients.

PubMed

Liao, Min-Tser; Liu, Wen-Chih; Lin, Fu-Huang; Huang, Ching-Feng; Chen, Shao-Yuan; Liu, Chuan-Chieh; Lin, Shih-Hua; Lu, Kuo-Cheng; Wu, Chia-Chao

2016-07-01

Inflammation, endothelial dysfunction, and mineral bone disease are critical factors contributing to morbidity and mortality in hemodialysis (HD) patients. Physical exercise alleviates inflammation and increases bone density. Here, we investigated the effects of intradialytic aerobic cycling exercise on HD patients. Forty end-stage renal disease patients undergoing HD were randomly assigned to either an exercise or control group. The patients in the exercise group performed a cycling program consisting of a 5-minute warm-up, 20 minutes of cycling at the desired workload, and a 5-minute cool down during 3 HD sessions per week for 3 months. Biochemical markers, inflammatory cytokines, nutritional status, the serum endothelial progenitor cell (EPC) count, bone mineral density, and functional capacity were analyzed. After 3 months of exercise, the patients in the exercise group showed significant improvements in serum albumin levels, the body mass index, inflammatory cytokine levels, and the number of cells positive for CD133, CD34, and kinase insert domain-conjugating receptor. Compared with the exercise group, the patients in the control group showed a loss of bone density at the femoral neck and no increases in EPCs. The patients in the exercise group also had a significantly greater 6-minute walk distance after completing the exercise program. Furthermore, the number of EPCs significantly correlated with the 6-minute walk distance both before and after the 3-month program. Intradialytic aerobic cycling exercise programs can effectively alleviate inflammation and improve nutrition, bone mineral density, and exercise tolerance in HD patients.

Operational Applications of Autogenic Feedback Training Exercise as a Treatment for Airsickness in the Military

NASA Technical Reports Server (NTRS)

Gebreyesus, Fiyore; Cowings, Patricia S.; Toscano, William B.

2012-01-01

Airsickness is experienced by about 50% of military aviators some time in their career. Aviators who suffer from recurrent episodes of airsickness are typically referred to the Naval Aerospace Medical Institute (NAMI) at Pensacola where they undergo extensive evaluation and 8 weeks of training in the Self-Paced Airsickness Desensitization (SPAD) program. Researchers at NASA Ames have developed an alternative mitigation training program, Autogenic Feedback Training Exercise (AFTE) that has demonstrated an 80% success rate for improving motion sickness tolerance.

[Improvement in quality of life and exercise capacity without muscular biology changes after general training in patients with severe chronic obstructive pulmonary disease].

PubMed

Pascual-Guardia, Sergio; Wodja, Emil; Gorostiza, Amaya; López de Santamaría, Elena; Gea, Joaquim; Gáldiz, Juan B; Sliwinski, Pawel; Barreiro, Esther

2013-03-02

Despite the beneficial effects of exercise training in chronic obstructive pulmonary disease (COPD) patients, several studies have revealed functional and biological abnormalities in their peripheral muscles. The objective was to determine whether exercise training of high intensity and long duration modifies oxidative stress levels and structure of respiratory and peripheral muscles of severe COPD patients, while also improving their exercise capacity and quality of life. Multicenter study (Warsaw and Barakaldo) in which 25 severe COPD out-patients were recruited from the COPD clinics. In all patients, lung and muscle functions, exercise capacity (walking test and cycloergometer) and quality of life (QoL) were assessed, and open muscle biopsies from the vastus lateralis and external intercostals (n=14) were obtained before and after an exercise training program of high intensity (respiratory rehabilitation area, 70% maximal tolerated load in a cycloergometer) and long duration (10 weeks). Oxidative stress and muscle structural modifications were evaluated in all muscle biopsies using immunoblotting and immunohistochemistry. In all patients, after the training program, without any drop-outs, exercise capacity and QoL improved significantly, whereas oxidative stress, muscle damage and structure were not modified in their respiratory or limb muscles compared to baseline. In patients with severe COPD, exercise training of high intensity and long duration significantly improves their exercise capacity and QoL, without inducing significant modifications on oxidative stress levels or muscle structure in their respiratory or peripheral muscles. These results may have future clinical therapeutic implications. Copyright © 2011 Elsevier España, S.L. All rights reserved.

Ineffectiveness of intravenous beta 2-agonists on improving exercise tolerance in patients with reversible chronic airway obstruction.

PubMed

Malerba, M; Boni, E; Tantucci, C; Filippi, B; Romagnoni, G; Grassi, V

1996-01-01

The effects on exercise tolerance after acute administration of beta 2-agonists were investigated in 11 patients with partly reversible chronic airway obstruction after 400 micrograms of salbutamol (S) given intravenously (i.v.) and after 400 micrograms i.v. of a new selective beta 2-agonist, broxaterol (B), by a cardiopulmonary incremental exercise test. At rest, while VE increased in respect to basal conditions (C) after S (from 13.3 +/- 2.2 to 14.4 +/- 2.8 l/min; p < 0.05) and after B (from 13.6 +/- 3.1 to 15.5 +/- 3.6 l/min; p < 0.05), VO2, VCO2 and VO2/HR showed no substantial variations. A small, not significant reduction of PaO2 was observed both after S (from 82.7 +/- 11.7 to 79.1 +/- 16.7 mm Hg) and B (from 81.6 +/- 10.5 to 78.0 +/- 11.0 mm Hg). The maximum workload increased neither after S (from 67.5 +/- 39.1 to 66.6 +/- 37.0 W) nor after B (from 65.7 +/- 39.3 to 60.0 +/- 35.8 W). At peak of exercise, VO2, VCO2 and VO2/HR did not change after S and B as compared with C, whereas VE remained higher after both beta 2-agonists throughout the effort. VO2 at ventilatory anaerobic threshold (AT) was significantly greater either after S (from 744 +/- 378 to 815 +/- 302 ml/min; p < 0.05) and after B (from 756 +/- 290 to 842 +/- 292 ml/min; p < 0.05). The PaO2 increase shown by these patients during effort was greater after beta 2-agonists administration, delta PaO2 from rest to peak of exercise amounting to 14.9 +/- 14.3 vs. 7.8 +/- 8.2 mm Hg after S and to 17.8 +/- 15.1 vs. 8.8 +/- 10.9 mm Hg after B, in respect to relative baseline (p < 0.05). We conclude that beta 2-agonists, when given acutely, do not improve exercise tolerance in patients with reversible chronic airflow obstruction, although these drugs can induce a small increment of ventilatory AT. In addition, arterial blood gases do not deteriorate at rest and are better preserved during exercise after beta 2-agonists.

Effects of Exercise Intensity on Postprandial Improvement in Glucose Disposal and Insulin Sensitivity in Prediabetic Adults

PubMed Central

Rynders, Corey A.; Weltman, Judy Y.; Jiang, Boyi; Breton, Marc; Patrie, James; Barrett, Eugene J.

2014-01-01

Background: A single bout of exercise improves postprandial glycemia and insulin sensitivity in prediabetic patients; however, the impact of exercise intensity is not well understood. The present study compared the effects of acute isocaloric moderate (MIE) and high-intensity (HIE) exercise on glucose disposal and insulin sensitivity in prediabetic adults. Methods: Subjects (n = 18; age 49 ± 14 y; fasting glucose 105 ± 11 mg/dL; 2 h glucose 170 ± 32 mg/dL) completed a peak O2 consumption/lactate threshold (LT) protocol plus three randomly assigned conditions: 1) control, 1 hour of seated rest, 2) MIE (at LT), and 3) HIE (75% of difference between LT and peak O2 consumption). One hour after exercise, subjects received an oral glucose tolerance test (OGTT). Plasma glucose, insulin, and C-peptide concentrations were sampled at 5- to 10-minute intervals at baseline, during exercise, after exercise, and for 3 hours after glucose ingestion. Total, early-phase, and late-phase area under the glucose and insulin response curves were compared between conditions. Indices of insulin sensitivity (SI) were derived from OGTT data using the oral minimal model. Results: Compared with control, SI improved by 51% (P = .02) and 85% (P < .001) on the MIE and HIE days, respectively. No differences in SI were observed between the exercise conditions (P = .62). Improvements in SI corresponded to significant reductions in the glucose, insulin, and C-peptide area under the curve values during the late phase of the OGTT after HIE (P < .05), with only a trend for reductions after MIE. Conclusion: These results suggest that in prediabetic adults, acute exercise has an immediate and intensity-dependent effect on improving postprandial glycemia and insulin sensitivity. PMID:24243632

Effects of exercise training alone vs a combined exercise and nutritional lifestyle intervention on glucose homeostasis in prediabetic individuals: a randomised controlled trial.

PubMed

Slentz, Cris A; Bateman, Lori A; Willis, Leslie H; Granville, Esther O; Piner, Lucy W; Samsa, Gregory P; Setji, Tracy L; Muehlbauer, Michael J; Huffman, Kim M; Bales, Connie W; Kraus, William E

2016-10-01

Although the Diabetes Prevention Program (DPP) established lifestyle changes (diet, exercise and weight loss) as the 'gold standard' preventive therapy for diabetes, the relative contribution of exercise alone to the overall utility of the combined diet and exercise effect of DPP is unknown; furthermore, the optimal intensity of exercise for preventing progression to diabetes remains very controversial. To establish clinical efficacy, we undertook a study (2009 to 2013) to determine: how much of the effect on measures of glucose homeostasis of a 6 month programme modelled after the first 6 months of the DPP is due to exercise alone; whether moderate- or vigorous-intensity exercise is better for improving glucose homeostasis; and to what extent amount of exercise is a contributor to improving glucose control. The primary outcome was improvement in fasting plasma glucose, with improvement in plasma glucose AUC response to an OGTT as the major secondary outcome. The trial was a parallel clinical trial. Sedentary, non-smokers who were 45-75 year old adults (n = 237) with elevated fasting glucose (5.28-6.94 mmol/l) but without cardiovascular disease, uncontrolled hypertension, or diabetes, from the Durham area, were studied at Duke University. They were randomised into one of four 6 month interventions: (1) low amount (42 kJ kg body weight(-1) week(-1) [KKW])/moderate intensity: equivalent of expending 42 KKW (e.g. walking ∼16 km [8.6 miles] per week) with moderate-intensity (50% [Formula: see text]) exercise; (2) high amount (67 KKW)/moderate intensity: equivalent of expending 67 KKW (∼22.3 km [13.8 miles] per week) with moderate-intensity exercise; (3) high amount (67 KKW)/vigorous intensity: equivalent to group 2, but with vigorous-intensity exercise (75% [Formula: see text]); and (4) diet + 42 KKW moderate intensity: same as group 1 but with diet and weight loss (7%) to mimic the first 6 months of the DPP. Computer-generated randomisation lists were provided by our statistician (G. P. Samsa). The randomisation list was maintained by L. H. Willis and C. A. Slentz with no knowledge of or input into the scheduling, whereas all scheduling was done by L. A. Bateman, with no knowledge of the randomisation list. Subjects were automatically assigned to the next group listed on the randomisation sheet (with no ability to manipulate the list order) on the day that they came in for the OGTT, by L. H. Willis. All plasma analysis was done blinded by the individuals doing the measurements (i.e. lipids, glucose, insulin). Subjects and research staff (other than individuals analysing the blood) were not blinded to the group assignments. Number randomised, completers and number analysed with complete OGTT data for each group were: low-amount/moderate-intensity (61, 43, 35); high-amount/moderate-intensity (61, 44, 40); high-amount/vigorous-intensity (61, 43, 38); diet/exercise (54, 45, 37), respectively. Only the diet and exercise group experienced a decrease in fasting glucose (p < 0.001). The means and 95% CIs for changes in fasting glucose (mmol/l) for each group were: high-amount/moderate-intensity -0.07 (-0.20, 0.06); high-amount/vigorous 0.06 (-0.07, 0.19); low-amount/moderate 0.05 (-0.05, 0.15); and diet/exercise -0.32 (-0.46, -0.18). The effects sizes for each group (in the same order) were: 0.17, 0.15, 0.18 and 0.71, respecively. For glucose tolerance (glucose AUC of OGTT), similar improvements were observed for the diet and exercise (8.2% improvement, effect size 0.73) and the 67 KKW moderate-intensity exercise (6.4% improvement, effect size 0.60) groups; moderate-intensity exercise was significantly more effective than the same amount of vigorous-intensity exercise (p < 0.0207). The equivalent amount of vigorous-intensity exercise alone did not significantly improve glucose tolerance (1.2% improvement, effect size 0.21). Changes in insulin AUC, fasting plasma glucose and insulin did not differ among the exercise groups and were numerically inferior to the diet and exercise group. In the present clinical efficacy trial we found that a high amount of moderate-intensity exercise alone was very effective at improving oral glucose tolerance despite a relatively modest 2 kg change in body fat mass. These data, combined with numerous published observations of the strong independent relation between postprandial glucose concentrations and prediction of future diabetes, suggest that walking ∼18.2 km (22.3 km prescribed with 81.6% adherence in the 67 KKW moderate-intensity group) per week may be nearly as effective as a more intensive multicomponent approach involving diet, exercise and weight loss for preventing the progression to diabetes in prediabetic individuals. These findings have important implications for the choice of clinical intervention to prevent progression to type 2 diabetes for those at high risk. ClinicalTrials.gov NCT00962962 FUNDING: The study was funded by National Institutes for Health National Institute of Diabetes and Digestive and Kidney Diseases (NIH-NDDK) (R01DK081559).

A progressive 5-week exercise therapy program leads to significant improvement in knee function early after anterior cruciate ligament injury.

PubMed

Eitzen, Ingrid; Moksnes, Håvard; Snyder-Mackler, Lynn; Risberg, May Arna

2010-11-01

Prospective cohort study without a control group. Firstly, to present our 5-week progressive exercise therapy program in the early stage after anterior cruciate ligament (ACL) injury. Secondly, to evaluate changes in knee function after completion of the program for patients with ACL injury in general and also when classified as potential copers or noncopers, and, finally, to examine potential adverse events. Few studies concerning early-stage ACL rehabilitation protocols exist. Consequently, little is known about the tolerance for, and outcomes from, short-term exercise therapy programs in the early stage after injury. One-hundred patients were included in a 5-week progressive exercise therapy program, within 3 months after injury. Knee function before and after completion of the program was evaluated from isokinetic quadriceps and hamstrings muscle strength tests, 4 single-leg hop tests, 2 different self-assessment questionnaires, and a global rating of knee function. A 2-way mixed-model analysis of variance was conducted to evaluate changes from pretest to posttest for the limb symmetry index for muscle strength and single-leg hop tests, and the change in scores for the patient-reported questionnaires. In addition, absolute values and the standardized response mean for muscle strength and single-leg hop tests were calculated at pretest and posttest for the injured and uninjured limb. Adverse events during the 5-week period were recorded. The progressive 5-week exercise therapy program led to significant improvements (P<.05) in knee function from pretest to posttest both for patients classified as potential copers and noncopers. Standardized response mean values for changes in muscle strength and single-leg hop performance from pretest to posttest for the injured limb were moderate to strong (0.49-0.84), indicating the observed improvements to be clinically relevant. Adverse events occurred in 3.9% of the patients. Short-term progressive exercise therapy programs are well tolerated and should be incorporated in early-stage ACL rehabilitation, either to improve knee function before ACL reconstruction or as a first step in further nonoperative management. Therapy, level 2b.

Effect of rowing ergometry and oral volume loading on cardiovascular structure and function during bed rest

PubMed Central

Hastings, Jeffrey L.; Krainski, Felix; Snell, Peter G.; Pacini, Eric L.; Jain, Manish; Bhella, Paul S.; Shibata, Shigeki; Fu, Qi; Palmer, M. Dean

2012-01-01

This study examined the effectiveness of a short-duration but high-intensity exercise countermeasure in combination with a novel oral volume load in preventing bed rest deconditioning and orthostatic intolerance. Bed rest reduces work capacity and orthostatic tolerance due in part to cardiac atrophy and decreased stroke volume. Twenty seven healthy subjects completed 5 wk of −6 degree head down bed rest. Eighteen were randomized to daily rowing ergometry and biweekly strength training while nine remained sedentary. Measurements included cardiac mass, invasive pressure-volume relations, maximal upright exercise capacity, and orthostatic tolerance. Before post-bed rest orthostatic tolerance and exercise testing, nine exercise subjects were given 2 days of fludrocortisone and increased salt. Sedentary bed rest led to cardiac atrophy (125 ± 23 vs. 115 ± 20 g; P < 0.001); however, exercise preserved cardiac mass (128 ± 38 vs. 137 ± 34 g; P = 0.002). Exercise training preserved left ventricular chamber compliance, whereas sedentary bed rest increased stiffness (180 ± 170%, P = 0.032). Orthostatic tolerance was preserved only when exercise was combined with volume loading (−10 ± 22%, P = 0.169) but not with exercise (−14 ± 43%, P = 0.047) or sedentary bed rest (−24 ± 26%, P = 0.035) alone. Rowing and supplemental strength training prevent cardiovascular deconditioning during prolonged bed rest. When combined with an oral volume load, orthostatic tolerance is also preserved. This combined countermeasure may be an ideal strategy for prolonged spaceflight, or patients with orthostatic intolerance. PMID:22345434

Is there an optimal level of positive expiratory pressure (PEP) to improve walking tolerance in patients with severe COPD?

PubMed

Russo, Davide; Simonelli, Carla; Paneroni, Mara; Saleri, Manuela; Piroddi, Ines Maria Grazia; Cardinale, Francesco; Vitacca, Michele; Nicolini, Antonello

2016-07-01

The application of positive expiratory pressure (PEP) devices during exercise had been proposed in order to counteract the pulmonary hyperinflation, reduce the dyspnea and thus increase the exercise tolerance in patients with severe chronic obstructive pulmonary disease (COPD). This randomized controlled crossover trial investigated the effect of two different levels of PEP (1 cmH2O and 10 cmH2O) on distance covered at 6minute walk test (6MWT) in patients with severe COPD. Secondary outcomes were the evaluation of PEP effects on physiological and pulmonary function variables. Seventy-two severe COPD patients, referred to our hospitals as in and out patients, were recruited. A basal 6MWT without devices was performed on the first day, and then repeated with PEP 1 cmH2O (PEP1) and 10 cmH2O (PEP10), with a randomized crossover design. Slow and forced spirometries, including the inspiratory capacity measure, were repeated before and after each 6MWT. 50 patients (average age 69,92 year, mean FEV1 41,42% of predicted) concluded the trial. The 6MWT improved significantly among both PEP levels and baseline (323,8 mt at baseline vs. 337,8 PEP1 and 341,8 PEP10; p<.002 and p<.018, respectively). The difference between PEP10 and PEP1 did not reach the significance. No improvements were found in pulmonary function, symptoms and physiological variables after the 6MWT. In patients with severe COPD, the application of 1 cmH2O of PEP seems to improve the exercise tolerance as 10 cmH2O, with similar dyspnea. Further studies should investigate the effects of low levels of PEP on aerobic training programs. Copyright © 2016 SEPAR. Published by Elsevier Espana. All rights reserved.

Effect of physical training in cool and hot environments on +Gz acceleration tolerance in women

NASA Technical Reports Server (NTRS)

Brock, P. J.; Sciaraffa, D.; Greenleaf, J. E.

1982-01-01

Acceleration tolerance, plasma volume, and maximal oxygen uptake were measured in 15 healthy women before and after submaximal isotonic exercise training periods in cool and hot environments. The women were divided on the basis of age, maximal oxygen uptake, and +Gz tolerance into three groups: a group that exercised in heat (40.6 C), a group that exercised at a lower temperature (18.7 C), and a sedentary control group that functioned in the cool environment. There was no significant change in the +Gz tolerance in any group after training, and terminal heart rates were similar within each group. It is concluded that induction of moderate acclimation responses without increases in sweat rate or resting plasma volume has no influence on +Gz acceleration tolerance in women.

Tolerance to exercise intensity modulates pleasure when exercising in music: The upsides of acoustic energy for High Tolerant individuals.

PubMed

Carlier, Mauraine; Delevoye-Turrell, Yvonne

2017-01-01

Moderate physical activity can be experienced by some as pleasurable and by others as discouraging. This may be why many people lack sufficient motivation to participate in the recommended 150 minutes of moderately intense exercise per week. In the present study, we assessed how pleasure and enjoyment were modulated differently by one's tolerance to self-paced physical activity. Sixty-three healthy individuals were allocated to three independent experimental conditions: a resting condition (watching TV), a cycling in silence condition, and a cycling in music condition. The tolerance threshold was assessed using the PRETIE-Questionnaire. Physical activity consisted in cycling during 30 minutes, at an intensity perceived as "somewhat difficult" on the Ratings of Perceived Exertion Scale. While controlling for self-reported physical activity level, results revealed that for the same perception of exertion and a similar level of enjoyment, the High Tolerance group produced more power output than the Low Tolerance group. There was a positive effect of music for High Tolerant individuals only, with music inducing greater power output and more pleasure. There was an effect of music on heart rate frequency in the Low Tolerant individuals without benefits in power output or pleasure. Our results suggest that for Low Tolerant individuals, energizing environments can interfere with the promised (positive) distracting effects of music. Hence, tolerance to physical effort must be taken into account to conceive training sessions that seek to use distracting methods as means to sustain pleasurable exercising over time.

A Cross-Sectional Study of the Prevalence of Exercise-Induced Hypertension in Childhood Following Repair of Coarctation of the Aorta.

PubMed

Luitingh, Taryn L; Lee, Melissa G Y; Jones, Bryn; Kowalski, Remi; Weskamp Aguero, Sofia; Koleff, Jane; Zannino, Diana; Cheung, Michael M H; d'Udekem, Yves

2018-03-27

Exercise-testing may be a more tolerable method of detecting hypertension in children after coarctation repair compared to gold-standard 24-hour ambulatory blood pressure (BP) monitoring (ABPM). This study aims to determine the prevalence of exercise-induced hypertension and end-organ damage in children after coarctation repair, and the effectiveness of exercise-testing compared to 24-hour ABPM in this population. Exercise-testing (Bruce protocol), transthoracic echocardiogram, 24-hour ABPM, and pulse wave velocity were performed in 41 patients aged 8 to 18 years with previous coarctation repair. Median age at repair was 13 days. Exercise-testing data were compared to healthy paediatric controls. Hypertension was defined as BP >95th percentile on 24-hour ABPM compared to normalised data, and systolic BP (SBP) arbitrarily >200mmHg on exercise-testing. After 13±3years, 39% (14/36) were hypertensive on 24-hour ABPM and 12% (5/41) on exercise-testing. Coarctation patients had a higher peak exercise SBP and reduced endurance compared to controls (164±26mmHg vs. 148±19mmHg, p=0.003; and 13.0±1.7mins vs. 14.2±2.4mins, p=0.007; respectively). All patients with a peak exercise SBP >190mmHg were hypertensive on 24-hour ABPM. Pulse wave velocity was higher in hypertensive patients on exercise-testing and 24-hour ABPM compared to normotensive patients (p=0.004 and p=0.06; respectively). Exercise-testing may be a useful tool to detect hypertension in children and young adults after coarctation repair, particularly in those who do not tolerate 24-hour ABPM. Normative peak exercise BP data for age should be obtained to improve the accuracy of exercise-testing in detecting hypertension. Copyright © 2018 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.

Benefits of regular walking exercise in advanced pre-dialysis chronic kidney disease.

PubMed

Kosmadakis, George C; John, Stephen G; Clapp, Emma L; Viana, Joao L; Smith, Alice C; Bishop, Nicolette C; Bevington, Alan; Owen, Paul J; McIntyre, Christopher W; Feehally, John

2012-03-01

There is increasing evidence of the benefit of regular physical exercise in a number of long-term conditions including chronic kidney disease (CKD). In CKD, this evidence has mostly come from studies in end stage patients receiving regular dialysis. There is little evidence in pre-dialysis patients with CKD Stages 4 and 5. A prospective study compared the benefits of 6 months regular walking in 40 pre-dialysis patients with CKD Stages 4 and 5. Twenty of them were the exercising group and were compared to 20 patients who were continuing with usual physical activity. In addition, the 40 patients were randomized to receive additional oral sodium bicarbonate (target venous bicarbonate 29 mmol/L) or continue with previous sodium bicarbonate treatment (target 24 mmol/L). Improvements noted after 1 month were sustained to 6 months in the 18 of 20 who completed the exercise study. These included improvements in exercise tolerance (reduced exertion to achieve the same activity), weight loss, improved cardiovascular reactivity, avoiding an increase in blood pressure medication and improvements in quality of health and life and uraemic symptom scores assessed by questionnaire. Sodium bicarbonate supplementation did not produce any significant alterations. This study provides further support for the broad benefits of aerobic physical exercise in CKD. More studies are needed to understand the mechanisms of these benefits, to study whether resistance exercise will add to the benefit and to evaluate strategies to promote sustained lifestyle changes, that could ensure continued increase in habitual daily physical activity levels.

An affordable, computerised, table-based exercise system for stroke survivors.

PubMed

King, Marcus; Hale, Leigh; Pekkari, Anna; Persson, Martin; Gregorsson, Malin; Nilsson, Mikaela

2010-07-01

Loss of hand function as a result of upper limb paresis after a stroke leads to reduced independence. Robotic-assisted therapy with virtual reality leads to improvements in motor function, but there is a need to improve the cost-benefit ratio of these therapies. This case series study investigated augmented reality computer games which provided a rewarded, goal-directed task to upper limb rehabilitation via a gravity supported reaching task. A computer game was developed to motivate chronic stroke survivors to undertake gravity supported reaching tasks performed on a table, and a focus group study investigated the application of this device for rehabilitation. From the focus group, a simple device was developed to improve the quality of the exercise and a further focus group study investigated a variety of computer games to determine motivations for undertaking rehabilitation exercises. Of the four participants in the case study, two showed improvement in ability to play the game and in arm function. Participants enjoyed playing a range of computer games and felt that the system provided a worthwhile exercise. Motivation for undertaking exercise with the system included: intellectual stimulation during game play, feedback such as game score, gaining physical benefits from the exercise, the system tolerating varying levels of disability, ability to relate to the game and ability to use the system in social groups. A low-cost device has been developed which increases the exercise of gravity supported reaching movements, provides goal-directed tasks with rewards and motivates the user to undertake extended rehabilitation.

[Exercise tolerance in patients with chronic obstructive pulmonary disease].

PubMed

Chlumský, J

2005-01-01

Limitation of exercise tolerance, especially activities of daily living, is the most significant clinical experience, which greatly affects quality of life of patients with chronic obstructive pulmonary disease (COPD). Many advances in the understanding of the pathophysiological mechanisms of bronchial obstruction in patients with COPD and their meanings for diagnosis and monitoring of the disease have occurred during the last two decades. The author discusses the most significant factors, which influence tolerance of physical exercise in patients with more advanced forms of COPD, and brings the attention to a practical test of physical capacity.

Caffeine and exercise.

PubMed

Paluska, Scott A

2003-08-01

Caffeine is the most commonly consumed drug in the world, and athletes frequently use it as an ergogenic aid. It improves performance and endurance during prolonged, exhaustive exercise. To a lesser degree it also enhances short-term, high-intensity athletic performance. Caffeine improves concentration, reduces fatigue, and enhances alertness. Habitual intake does not diminish caffeine's ergogenic properties. Several mechanisms have been proposed to explain the physiologic effects of caffeine, but adenosine receptor antagonism most likely accounts for the primary mode of action. It is relatively safe and has no known negative performance effects, nor does it cause significant dehydration or electrolyte imbalance during exercise. Routine caffeine consumption may cause tolerance or dependence, and abrupt discontinuation produces irritability, mood shifts, headache, drowsiness, or fatigue. Major sport governing bodies ban excessive use of caffeine, but current monitoring techniques are inadequate, and ethical dilemmas persist regarding caffeine intake by athletes.

Heat Acclimation and Water-Immersion Deconditioning: Fluid Electrolyte Shifts with Tilting

NASA Technical Reports Server (NTRS)

Conertino, V. A.; Shvartz, E.; Haines, R. F.; Bhattacharya, A.; Superinde, S. J.; Keil, L. C.; Greenlean, J. E.

1977-01-01

One of the major problems encountered by astronauts exposed to space flight is a reduction of orthostatic tolerance on return to earth. Many studies have been performed in an attempt to define the physiologic mechanism of orthostatic intolerance and to develop some remedial treatment. Exercise training does not appear to enhance orthostatic tolerance . In contrast, heat acclimation (i.e., exercise training in the heat) has been reported to enhance orthostatic tolerance. Since plasma volume increases with both exercise training and heat acclimation, it is not clear what role fluid and electrolytes play in determining tolerance to hydrostatic pressure. The purpose of this study was to compare the effects of exercise training in a cool environment and heat acclimation on resting plasma volume (PV) and the ensuing fluid and electrolyte shifts which occur during head-up tilting before and after water immersion deconditioning.

Lower-body negative-pressure exercise and bed-rest-mediated orthostatic intolerance

NASA Technical Reports Server (NTRS)

Schneider, Suzanne M.; Watenpaugh, Donald E.; Lee, Stuart M C.; Ertl, Andrew C.; Williams, W. Jon; Ballard, Richard E.; Hargens, Alan R.

2002-01-01

PURPOSE: Supine, moderate exercise is ineffective in maintaining orthostatic tolerance after bed rest (BR). Our purpose was to test the hypothesis that adding an orthostatic stress during exercise would maintain orthostatic function after BR. METHODS: Seven healthy men completed duplicate 15-d 6 degrees head-down tilt BR using a crossover design. During one BR, subjects did not exercise (CON). During another BR, subjects exercised for 40 min.d(-1) on a supine treadmill against 50-60 mm Hg LBNP (EX). Exercise training consisted of an interval exercise protocol of 2- to 3-min intervals alternating between 41 and 65% (.)VO(2max). Before and after BR, an LBNP tolerance test was performed in which the LBNP chamber was decompressed in 10-mm Hg stages every 3 min until presyncope. RESULTS: LBNP tolerance, as assessed by the cumulative stress index (CSI) decreased after BR in both the CON (830 +/- 144, pre-BR vs 524 +/- 56 mm Hg.min, post-BR) and the EX (949 +/- 118 pre-BR vs 560 +/- 44 mm Hg.min, post-BR) conditions. However, subtolerance (0 to -50 mm Hg LBNP) heart rates were lower and systolic blood pressures were better maintained after BR in the EX condition compared with CON. CONCLUSION: Moderate exercise performed against LBNP simulating an upright 1-g environment failed to protect orthostatic tolerance after 15 d of BR.

Physical exercise restores microvascular function in obese rats with metabolic syndrome.

PubMed

Machado, Marcus Vinicius; Vieira, Aline Bomfim; Nascimento, Alessandro Rodrigues; Martins, Rômulo Lanza; Daleprane, Julio Beltrame; Lessa, Marcos Adriano; Tibiriçá, Eduardo

2014-11-01

Obesity and metabolic syndrome are related to systemic functional microvascular alterations, including a significant reduction in microvessel density. The aim of this study was to investigate the effects of exercise training on functional capillary density in the skeletal muscle and skin of obese rats with metabolic syndrome. We used male Wistar-Kyoto rats that had been fed a standard commercial diet (CON) or high-fat diet (HFD) for 32 weeks. Animals receiving the HFD were randomly divided into sedentary (HFD+SED) and training groups (HFD+TR) at the 20(th) week. After 12 weeks of aerobic treadmill training, the maximal oxygen uptake (VO2max); hemodynamic, biochemical, and anthropometric parameters; and functional capillary density were assessed. In addition, a maximal exercise test was performed. Exercise training increased the VO2max (69 ± 3 mL/kg per min) and exercise tolerance (30 ± 1 min) compared with the HFD+SED (41 ± 6 mL/kg per min, P < 0.05 and 16 ± 1 min, P < 0.001) and with the CON (52 ± 7 mL/kg per min and 18 ± 1 min, P < 0.05) groups. The HFD+TR group also showed reduced retroperitoneal fat (0.03 ± 0.00 vs. 0.05 ± 0.00 gram/gram, P < 0.001), epididymal fat (0.01 ± 0.00 vs. 0.02 ± 0.00 gram/gram, P < 0.001), and systolic blood pressure (127 ± 2 vs. 150 ± 2 mmHg, P<0.001). The HFD+TR group also demonstrated improved glucose tolerance, as evaluated by an intraperitoneal glucose tolerance test, fasting plasma glucose levels (5.0 ± 0.1 vs. 6.4 ± 0.2 mmol/L, P<0.001) and fasting plasma insulin levels (26.5 ± 2.3 vs. 38.9 ± 3.7 μIU/mL, P < 0.05). Glucose tolerance did not differ between HFD+TR and CON groups. Exercise training also increased the number of spontaneously perfused capillaries in the skeletal muscle (252 ± 9 vs. 207 ± 9 capillaries/mm(2)) of the training group compared with that in the sedentary animals (260 ± 15 capillaries/mm(2)). These results demonstrate that exercise training reverses capillary rarefaction in our experimental model of metabolic syndrome and obesity.

Short-Term Exercise Training Does Not Stimulate Skeletal Muscle ATP Synthesis in Relatives of Humans With Type 2 Diabetes

PubMed Central

Kacerovsky-Bielesz, Gertrud; Chmelik, Marek; Ling, Charlotte; Pokan, Rochus; Szendroedi, Julia; Farukuoye, Michaela; Kacerovsky, Michaela; Schmid, Albrecht I.; Gruber, Stephan; Wolzt, Michael; Moser, Ewald; Pacini, Giovanni; Smekal, Gerhard; Groop, Leif; Roden, Michael

2009-01-01

OBJECTIVE We tested the hypothesis that short-term exercise training improves hereditary insulin resistance by stimulating ATP synthesis and investigated associations with gene polymorphisms. RESEARCH DESIGN AND METHODS We studied 24 nonobese first-degree relatives of type 2 diabetic patients and 12 control subjects at rest and 48 h after three bouts of exercise. In addition to measurements of oxygen uptake and insulin sensitivity (oral glucose tolerance test), ectopic lipids and mitochondrial ATP synthesis were assessed using1H and31P magnetic resonance spectroscopy, respectively. They were genotyped for polymorphisms in genes regulating mitochondrial function, PPARGC1A (rs8192678) and NDUFB6 (rs540467). RESULTS Relatives had slightly lower (P = 0.012) insulin sensitivity than control subjects. In control subjects, ATP synthase flux rose by 18% (P = 0.0001), being 23% higher (P = 0.002) than that in relatives after exercise training. Relatives responding to exercise training with increased ATP synthesis (+19%, P = 0.009) showed improved insulin sensitivity (P = 0.009) compared with those whose insulin sensitivity did not improve. A polymorphism in the NDUFB6 gene from respiratory chain complex I related to ATP synthesis (P = 0.02) and insulin sensitivity response to exercise training (P = 0.05). ATP synthase flux correlated with O2uptake and insulin sensitivity. CONCLUSIONS The ability of short-term exercise to stimulate ATP production distinguished individuals with improved insulin sensitivity from those whose insulin sensitivity did not improve. In addition, the NDUFB6 gene polymorphism appeared to modulate this adaptation. This finding suggests that genes involved in mitochondrial function contribute to the response of ATP synthesis to exercise training. PMID:19265027

The Health Benefits and Challenges of Exercise Training in Persons Living with Schizophrenia: A Pilot Study

PubMed Central

Bredin, Shannon S. D.; Warburton, Darren E. R.; Lang, Donna J.

2013-01-01

Background: In addition to the hallmark cognitive and functional impairments mounting evidence indicates that schizophrenia is also associated with an increased risk for the development of secondary complications, in particular cardio-metabolic disease. This is thought to be the result of various factors including physical inactivity and the metabolic side effects of psychotropic medications. Therefore, non-pharmacological approaches to improving brain health, physical health, and overall well-being have been promoted increasingly. Methods: We report on the health-related physical fitness (body composition, blood pressure, heart rate, and aerobic fitness) and lipid profile of persons living with schizophrenia and effective means to address the challenges of exercise training in this population. Results: There was a markedly increased risk for cardio-metabolic disease in 13 persons living with schizophrenia (Age = 31 ± 7 years) including low aerobic fitness (76% ± 34% of predicted), reduced HDL (60% of cohort), elevated resting heart rate (80% of cohort), hypertension (40% of cohort), overweight and obesity (69% of cohort), and abdominal obesity (54% of cohort). Individualized exercise prescription (3 times/week) was well tolerated, with no incidence of adverse exercise-related events. The exercise adherence rate was 81% ± 21% (Range 48%–100%), and 69% of the participants were able to complete the entire exercise training program. Exercise training resulted in clinically important changes in physical activity, aerobic fitness, exercise tolerance, blood pressure, and body composition. Conclusion: Persons living with schizophrenia appear to be at an increased risk for cardio-metabolic disease. An individualized exercise program has shown early promise for the treatment of schizophrenia and the various cognitive, functional, and physiological impairments that ultimately affect health and well-being. PMID:24961427

Dietary nitrate supplementation: impact on skeletal muscle vascular control in exercising rats with chronic heart failure

PubMed Central

Ferguson, Scott K.; Holdsworth, Clark T.; Colburn, Trenton D.; Wright, Jennifer L.; Craig, Jesse C.; Fees, Alex; Jones, Andrew M.; Allen, Jason D.; Musch, Timothy I.

2016-01-01

Chronic heart failure (CHF) results in central and peripheral derangements that ultimately reduce skeletal muscle O2 delivery and impair exercise tolerance. Dietary nitrate (NO3−) supplementation improves skeletal muscle vascular function and tolerance to exercise. We tested the hypothesis that NO3− supplementation would elevate exercising skeletal muscle blood flow (BF) and vascular conductance (VC) in CHF rats. Myocardial infarction (MI) was induced (coronary artery ligation) in young adult male rats. After 21 days of recovery, rats randomly received 5 days of NO3−-rich beetroot juice (CHF + BR, n = 10) or a placebo (CHF, n = 10). Mean arterial pressure (carotid artery catheter) and skeletal muscle BF (radiolabeled microspheres) were measured during treadmill exercise (20 m/min, 5% grade). CHF-induced dysfunction, as determined by myocardial infarction size (29 ± 3% and 33 ± 4% in CHF and CHF + BR, respectively) and left ventricular end-diastolic pressure (18 ± 2 and 18 ± 2 mmHg in CHF and CHF + BR, respectively), and exercising mean arterial pressure (131 ± 3 and 128 ± 4 mmHg in CHF and CHF + BR, respectively) were not different (P > 0.05) between groups. Total exercising hindlimb skeletal muscle BF (95 ± 5 and 116 ± 9 ml·min−1·100 g−1 in CHF and CHF + BR, respectively) and VC (0.75 ± 0.05 and 0.90 ± 0.05 ml·min−1·100 g−1·mmHg−1 in CHF and CHF + BR, respectively) were 22% and 20% greater in BR-supplemented rats, respectively (P < 0.05). During exercise, BF in 9 and VC in 10 hindlimb muscles and muscle portions were significantly greater in the CHF + BR group. These results provide strong evidence that dietary NO3− supplementation improves skeletal muscle vascular function during exercise in rats with CHF and, thus, support the use of BR as a novel therapeutic modality for the treatment of CHF. PMID:27445296

Dietary nitrate supplementation: impact on skeletal muscle vascular control in exercising rats with chronic heart failure.

PubMed

Ferguson, Scott K; Holdsworth, Clark T; Colburn, Trenton D; Wright, Jennifer L; Craig, Jesse C; Fees, Alex; Jones, Andrew M; Allen, Jason D; Musch, Timothy I; Poole, David C

2016-09-01

Chronic heart failure (CHF) results in central and peripheral derangements that ultimately reduce skeletal muscle O2 delivery and impair exercise tolerance. Dietary nitrate (NO3 (-)) supplementation improves skeletal muscle vascular function and tolerance to exercise. We tested the hypothesis that NO3 (-) supplementation would elevate exercising skeletal muscle blood flow (BF) and vascular conductance (VC) in CHF rats. Myocardial infarction (MI) was induced (coronary artery ligation) in young adult male rats. After 21 days of recovery, rats randomly received 5 days of NO3 (-)-rich beetroot juice (CHF + BR, n = 10) or a placebo (CHF, n = 10). Mean arterial pressure (carotid artery catheter) and skeletal muscle BF (radiolabeled microspheres) were measured during treadmill exercise (20 m/min, 5% grade). CHF-induced dysfunction, as determined by myocardial infarction size (29 ± 3% and 33 ± 4% in CHF and CHF + BR, respectively) and left ventricular end-diastolic pressure (18 ± 2 and 18 ± 2 mmHg in CHF and CHF + BR, respectively), and exercising mean arterial pressure (131 ± 3 and 128 ± 4 mmHg in CHF and CHF + BR, respectively) were not different (P > 0.05) between groups. Total exercising hindlimb skeletal muscle BF (95 ± 5 and 116 ± 9 ml·min(-1)·100 g(-1) in CHF and CHF + BR, respectively) and VC (0.75 ± 0.05 and 0.90 ± 0.05 ml·min(-1)·100 g(-1)·mmHg(-1) in CHF and CHF + BR, respectively) were 22% and 20% greater in BR-supplemented rats, respectively (P < 0.05). During exercise, BF in 9 and VC in 10 hindlimb muscles and muscle portions were significantly greater in the CHF + BR group. These results provide strong evidence that dietary NO3 (-) supplementation improves skeletal muscle vascular function during exercise in rats with CHF and, thus, support the use of BR as a novel therapeutic modality for the treatment of CHF. Copyright © 2016 the American Physiological Society.

Physiological tradeoffs may underlie the evolution of hypoxia tolerance and exercise performance in sunfish (Centrarchidae).

PubMed

Crans, Kyle D; Pranckevicius, Nicole A; Scott, Graham R

2015-10-01

Tradeoffs between hypoxia tolerance and aerobic exercise performance appear to exist in some fish taxa, even though both of these traits are often associated with a high O2 transport capacity. We examined the physiological basis for this potential tradeoff in four species of sunfish from the family Centrarchidae. Hypoxia tolerance was greatest in rock bass, intermediate in pumpkinseed and bluegill and lowest in largemouth bass, based on measurements of critical O2 tension (Pcrit) and O2 tension at loss of equilibrium (PO2 at LOE). Consistent with there being a tradeoff between hypoxia tolerance and aerobic exercise capacity, the least hypoxia-tolerant species had the highest critical swimming speed (Ucrit) during normoxia and suffered the greatest decrease in Ucrit in hypoxia. There was also a positive correlation between Ucrit in normoxia and PO2 at LOE, which remained significant after accounting for phylogeny using phylogenetically independent contrasts. Several sub-organismal traits appeared to contribute to both hypoxia tolerance and aerobic exercise capacity (reflected by traits that were highest in both rock bass and largemouth bass), such as the gas-exchange surface area of the gills, the pH sensitivity of haemoglobin-O2 affinity, and the activities of lactate dehydrogenase and the gluconeogenic enzyme phosphoenolpyruvate carboxykinase in the liver. Some other sub-organismal traits were uniquely associated with either hypoxia tolerance (low sensitivity of haemoglobin-O2 affinity to organic phosphates, high pyruvate kinase and lactate dehydrogenase activities in the heart) or aerobic exercise capacity (capillarity and fibre size of the axial swimming muscle). Therefore, the cumulative influence of a variety of respiratory and metabolic traits can result in physiological tradeoffs associated with the evolution of hypoxia tolerance and aerobic exercise performance in fish. © 2015. Published by The Company of Biologists Ltd.

Home-based pulmonary rehabilitation in patients with chronic obstructive pulmonary disease: a randomized clinical trial

PubMed Central

Dias, Fernanda Dultra; Sampaio, Luciana Maria Malosá; da Silva, Graziela Alves; Gomes, Évelim LF Dantas; do Nascimento, Eloisa Sanches Pereira; Alves, Vera Lucia Santos; Stirbulov, Roberto; Costa, Dirceu

2013-01-01

Introduction Pulmonary rehabilitation (PR) is a multidisciplinary program of care for patients with chronic obstructive pulmonary disease (COPD) with the goal of improving the functional capacity and quality of life, as well as maintaining the clinical stability of COPD sufferers. However, not all patients are available for such a program despite discomfort with their condition. The aim of this study was to evaluate the effects of a home-based PR (HBPR) program on functional ability, quality of life, and respiratory muscle strength and endurance. Patients and methods Patients with COPD according to the Global Initiative of Chronic Obstructive Lung Disease were randomized (double-blind) into two groups. One group performed a protocol at home with aerobic and muscle strength exercises and was called the intervention group; the other group received only instructions to perform breathing and stretching exercises, characterizing it as the control group (CG). We assessed the following variables at baseline and 2 months: exercise tolerance (incremental shuttle walk test and upper limb test), respiratory muscle (strength and endurance test), and health-related quality of life (Airways Questionnaire 20). Results There were no significant changes after the intervention in either of the two groups in exercise tolerance and quality of life. However, the intervention group had improved respiratory endurance compared with the CG, while the CG presented a decrease in the load sustained by the respiratory muscles after the HBPR. Conclusion A program of HBPR with biweekly supervision (although not enough to provide significant improvements in physical capacity or quality of life) played an important role in maintaining the stability of the clinical features of patients with COPD; the patients had no worsening of symptoms during the intervention period according to the daily log. PMID:24235824

Aerobic capacity, orthostatic tolerance, and exercise perceptions at discharge from inpatient spinal cord injury rehabilitation.

PubMed

Pelletier, Chelsea A; Jones, Graham; Latimer-Cheung, Amy E; Warburton, Darren E; Hicks, Audrey L

2013-10-01

To describe physical capacity, autonomic function, and perceptions of exercise among adults with subacute spinal cord injury (SCI). Cross-sectional. Two inpatient SCI rehabilitation programs in Canada. Participants (N=41; mean age ± SD, 38.9 ± 13.7y) with tetraplegia (TP; n=19), high paraplegia (HP; n=8), or low paraplegia (LP; n=14) completing inpatient SCI rehabilitation (mean ± SD, 112.9 ± 52.5d postinjury). Not applicable. Peak exercise capacity was determined by an arm ergometry test. As a measure of autonomic function, orthostatic tolerance was assessed by a passive sit-up test. Self-efficacy for exercise postdischarge was evaluated by a questionnaire. There was a significant difference in peak oxygen consumption and heart rate between participants with TP (11.2 ± 3.4;mL·kg(-1)·min(-1) 113.9 ± 19.7 beats/min) and LP (17.1 ± 7.5 mL·kg(-1)·min(-1); 142.8 ± 22.7 beats/min). Peak power output was also significantly lower in the TP group (30.0 ± 6.9W) compared with the HP (55.5 ± 7.56W) and LP groups (62.5 ± 12.2W). Systolic blood pressure responses to the postural challenge varied significantly between groups (-3.0 ± 33.5 mmHg in TP, 17.8 ± 14.7 mmHg in HP, 21.6 ± 18.7 mmHg in LP). Orthostatic hypotension was most prevalent among participants with motor complete TP (73%). Results from the questionnaire revealed that although participants value exercise and see benefits to regular participation, they have low confidence in their abilities to perform the task of either aerobic or strengthening exercise. Exercise is well tolerated in adults with subacute SCI. Exercise interventions at this stage should focus on improving task-specific self-efficacy, and attention should be made to blood pressure regulation, particularly in individuals with motor complete TP. Copyright © 2013 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

How to diminish calcium loss and muscle atrophy in space

NASA Astrophysics Data System (ADS)

Gorgolewski, S.

Humans in micro-gravity suffer from Ca loss and muscle atrophy, efforts are made to prevent it by means of physical exercises and with medicaments. The tread-mill and exercise bike are just two most frequently used examples. This can and should be widely extended, and in such a way as to mimic as close as possible the normal loading of the muscles and skeleton which we experience here on the earth. Special very light weight active harness is proposed which monitors the body loading. This is accomplished by means of computer aided monitoring of muscle and bone loading systems. Using feedback it helps the crew to load their bodies and skeletons in the same way as it happens here on the earth. The active exercise mat with pressure sensors first creates a record here on the earth of all normal muscle tensions during exercise. In space the computer guides each exercising crew member to follow their earthbound training routine. High care is needed to select the best and most effective exercises which should demand least energy, yet providing the very best results. May I suggest the very best known to me kind of comprehensive exercises: Yoga. Doing it on the Earth you need next to none special training equipment. Our body is in principle all we need here to do Yoga exercises on the Earth. Integral part of Yoga exercises are abdominal breathing exercises, which can slow down the breathing rate even threefold. This improves the oxygen and CO_2 exchange and massages all internal organs around the clock, helping the adept to stay fit and also keeps their minds steady and calm. Yoga exercises should be mastered already here on the earth, providing the crew with much greater tolerance to micro-gravity. In Yoga we acquire the tolerance not only to zero gravity but also to "negative" gravity: as it happens in all inverted positions. This should help the astronauts to be more tolerant of the half way only step into "zero gravity". Weightlessness state provides us the ultimate in perfect relaxation when asleep or awake. We have to check in space if we can thus diminish the use of medicaments or even eliminate them. Slow Yoga exercises decrease also the amount on food required because life is not so energy demanding in space as it is here under the earth's gravitation. We can stay lean and healthy with such static yet most effective physical exercises. In addition it gives us for free a vegetarian life style, just another benefit so useful in space travel.

Head to Head Comparison of Short-Term Treatment with the NAD(+) Precursor Nicotinamide Mononucleotide (NMN) and 6 Weeks of Exercise in Obese Female Mice.

PubMed

Uddin, Golam M; Youngson, Neil A; Sinclair, David A; Morris, Margaret J

2016-01-01

Obesity is well known to be a major cause of several chronic metabolic diseases, which can be partially counteracted by exercise. This is due, in part, to an upregulation of mitochondrial activity through increased nicotinamide adenine dinucleotide (NAD(+)). Recent studies have shown that NAD(+) levels can be increased by using the NAD(+) precursor, nicotinamide mononucleotide (NMN) leading to the suggestion that NMN could be a useful intervention in diet related metabolic disorders. In this study we compared the metabolic, and especially mitochondrial-associated, effects of exercise and NMN in ameliorating the consequences of high-fat diet (HFD) induced obesity in mice. Sixty female 5 week old C57BL6/J mice were allocated across five groups: Chow sedentary: CS; Chow exercise: CEX; HFD sedentary: HS; HFD NMN: HNMN; HFD exercise: HEX (12/group). After 6 weeks of diet, exercise groups underwent treadmill exercise (15 m/min for 45 min), 6 days per week for 6 weeks. NMN or vehicle (500 mg/kg body weight) was injected (i.p.) daily for the last 17 days. No significant alteration in body weight was observed in response to exercise or NMN. The HFD significantly altered adiposity, glucose tolerance, plasma insulin, NADH levels and citrate synthase activity in muscle and liver. HEX and HNMN groups both showed significantly improved glucose tolerance compared to the HS group. NAD(+) levels were increased significantly both in muscle and liver by NMN whereas exercise increased NAD(+) only in muscle. Both NMN and exercise ameliorated the HFD-induced reduction in liver citrate synthase activity. However, exercise, but not NMN, ameliorated citrate synthase activity in muscle. Overall these data suggest that while exercise and NMN-supplementation can induce similar reversal of the glucose intolerance induced by obesity, they are associated with tissue-specific effects and differential alterations to mitochondrial function in muscle and liver.

Improved Insulin Sensitivity After Exercise Training is Linked to Reduced Plasma C14:0 Ceramide in Obesity and Type 2 Diabetes

PubMed Central

Kasumov, Takhar; Solomon, Thomas P.J.; Hwang, Calvin; Huang, Hazel; Haus, Jacob M.; Zhang, Renliang; Kirwan, John P.

2015-01-01

Objective To assess the effect of exercise training on insulin sensitivity and plasma ceramides in obesity and type 2 diabetes (T2D). Methods Twenty-four adults with obesity and normal glucose tolerance (NGT, n=14), or diabetes (n=10) were studied before and after a 12-week supervised exercise-training program (5 d/wk, 1 hr/d, 80–85% of maximum heart rate). Changes in body composition were assessed using hydrostatic weighing and computed tomography. Peripheral tissue insulin sensitivity was assessed by a 40 mU/m2/min hyperinsulinemic euglycemic clamp. Plasma ceramides (C14:0, C16:0, C18:0, C18:1, C20:0, C24:0 and C24:1) were quantified using electrospray ionization tandem mass spectrometry after separation with HPLC. Results Plasma ceramides were similar for the obese NGT and subjects with diabetes, despite differences in glucose tolerance. Exercise significantly reduced body weight and adiposity, and increased peripheral insulin sensitivity in both groups (P<0.05). In addition, plasma C14:0, C16:0, C18:1, and C24:0 ceramide levels were reduced in all subjects following the intervention (P<0.05). Decreases in total (r=-0.51, P=0.02) and C14:0 (r=-0.56, P=0.009) ceramide were negatively correlated with the increase in insulin sensitivity. Conclusion Ceramides are linked to exercise training-induced improvements in insulin sensitivity, and plasma C14:0 ceramide may provide a specific target for investigating lipid-related insulin resistance in obesity and T2D. PMID:25966363

Improved insulin sensitivity after exercise training is linked to reduced plasma C14:0 ceramide in obesity and type 2 diabetes.

PubMed

Kasumov, Takhar; Solomon, Thomas P J; Hwang, Calvin; Huang, Hazel; Haus, Jacob M; Zhang, Renliang; Kirwan, John P

2015-07-01

To assess the effect of exercise training on insulin sensitivity and plasma ceramides in obesity and type 2 diabetes (T2D). Twenty-four adults with obesity and normal glucose tolerance (NGT, n = 14) or diabetes (n = 10) were studied before and after a 12-week supervised exercise-training program (5 days/week, 1 h/day, 80-85% of maximum heart rate). Changes in body composition were assessed using hydrostatic weighing and computed tomography. Peripheral tissue insulin sensitivity was assessed by a 40 mU/m(2) /min hyperinsulinemic euglycemic clamp. Plasma ceramides (C14:0, C16:0, C18:0, C18:1, C20:0, C24:0, and C24:1) were quantified using electrospray ionization tandem mass spectrometry after separation with HPLC. Plasma ceramides were similar for the subjects with obesity and NGT and the subjects with diabetes, despite differences in glucose tolerance. Exercise significantly reduced body weight and adiposity and increased peripheral insulin sensitivity in both groups (P < 0.05). In addition, plasma C14:0, C16:0, C18:1, and C24:0 ceramide levels were reduced in all subjects following the intervention (P < 0.05). Decreases in total (r = -0.51, P = 0.02) and C14:0 (r = -0.56, P = 0.009) ceramide were negatively correlated with the increase in insulin sensitivity. Ceramides are linked to exercise training-induced improvements in insulin sensitivity, and plasma C14:0 ceramide may provide a specific target for investigating lipid-related insulin resistance in obesity and T2D. © 2015 The Obesity Society.

Tennis Training Sessions as a Rehabilitation Instrument for Patients after Acute Myocardial Infarction

PubMed Central

García, Juan P. F.; Giraldo, Víctor M. A.; Barrado, José J. G.; Casasola, César D.

2013-01-01

The aims of this study were to measure the effects of a cardiac rehabilitation program based on a modification of a sport (tennis) on quality of life, on various laboratory test parameters and on an exercise stress test, and to determine if the results of this novel activity are equivalent to those of traditional programs (i.e., the use of the bicycle ergometer). The sample consisted of 79 patients with a low-risk acute coronary syndrome. They were divided into three groups: two experimental groups and one control group. One of the experimental groups used the bicycle ergometer as its main physical activity, whereas the other received training in a modified form of tennis lesson. By the end of the 3-month program, triglycerides, cholesterol LDL, cholesterol HDL, (-25 mg·dl-1 and 32.3 mg·dl-1 final, and 15.7 mg·dl-1 and 23.3 mg·dl-1 LDL final, respectively) and exercise capacity improved significantly (by 1.1 metabolic equivalents (METs) and 1.2 METs, respectively), in both experimental groups. We conclude that the application of a comprehensive cardiac rehabilitation program in patients with low-risk acute coronary syndrome based on a program of modified tennis improves exercise tolerance and metabolic parameters, as well as certain physical characteristics that reduce cardiovascular risk. Key Points Cardiac rehabilitation of low risk patients with acute coronary syndrome based on a program of modified tennis produces an improvement in quality of life, lipid profiles and in exercise tolerance A cardiac rehabilitation program based on a modification of tennis produces favourable changes in various anthropometric parameters related to the reduction of cardiovascular risk The development of programs of cardiac rehabilitation based on modified versions of various sports would advantage the adherence to physical exercise. PMID:24149811

The glucose-dependent insulinotropic polypeptide and glucose-stimulated insulin response to exercise training and diet in obesity.

PubMed

Kelly, Karen R; Brooks, Latina M; Solomon, Thomas P J; Kashyap, Sangeeta R; O'Leary, Valerie B; Kirwan, John P

2009-06-01

Aging and obesity are characterized by decreased beta-cell sensitivity and defects in the potentiation of nutrient-stimulated insulin secretion by GIP. Exercise and diet are known to improve glucose metabolism and the pancreatic insulin response to glucose, and this effect may be mediated through the incretin effect of GIP. The purpose of this study was to assess the effects of a 12-wk exercise training intervention (5 days/wk, 60 min/day, 75% Vo(2 max)) combined with a eucaloric (EX, n = 10) or hypocaloric (EX-HYPO, pre: 1,945 +/- 190, post: 1,269 +/- 70, kcal/day; n = 9) diet on the GIP response to glucose in older (66.8 +/- 1.5 yr), obese (34.4 +/- 1.7 kg/m(2)) adults with impaired glucose tolerance. In addition to GIP, plasma PYY(3-36), insulin, and glucose responses were measured during a 3-h, 75-g oral glucose tolerance test. Both interventions led to a significant improvement in Vo(2 max) (P < 0.05). Weight loss (kg) was significant in both groups but was greater after EX-HYPO (-8.3 +/- 1.1 vs. -2.8 +/- 0.5, P = 0.002). The glucose-stimulated insulin response was reduced after EX-HYPO (P = 0.02), as was the glucose-stimulated GIP response (P < 0.05). Furthermore, after the intervention, changes in insulin (DeltaI(0-30)/DeltaG(0-30)) and GIP (Delta(0-30)) secretion were correlated (r = 0.69, P = 0.05). The PYY(3-36) (Delta(0-30)) response to glucose was increased after both interventions (P < 0.05). We conclude that 1) a combination of caloric restriction and exercise reduces the GIP response to ingested glucose, 2) GIP may mediate the attenuated glucose-stimulated insulin response after exercise/diet interventions, and 3) the increased PYY(3-36) response represents an improved capacity to regulate satiety and potentially body weight in older, obese, insulin-resistant adults.

Increasing quality of life in pulmonary arterial hypertension: is there a role for nutrition?

PubMed

Vinke, Paulien; Jansen, Suzanne M; Witkamp, Renger F; van Norren, Klaske

2018-06-16

Pulmonary arterial hypertension (PAH) is a progressive disease primarily affecting the pulmonary vasculature and heart. PAH patients suffer from exercise intolerance and fatigue, negatively affecting their quality of life. This review summarizes current insights in the pathophysiological mechanisms underlying PAH. It zooms in on the potential involvement of nutritional status and micronutrient deficiencies on PAH exercise intolerance and fatigue, also summarizing the potential benefits of exercise and nutritional interventions. Pubmed/Medline, Scopus, and Web of Science were searched for publications on pathophysiological mechanisms of PAH negatively affecting physical activity potential and nutritional status, and for potential effects of interventions involving exercise or nutritional measures known to improve exercise intolerance. Pathophysiological processes that contribute to exercise intolerance and impaired quality of life of PAH patients include right ventricular dysfunction, inflammation, skeletal muscle alterations, and dysfunctional energy metabolism. PAH-related nutritional deficiencies and metabolic alterations have been linked to fatigue, exercise intolerance, and endothelial dysfunction. Available evidence suggests that exercise interventions can be effective in PAH patients to improve exercise tolerance and decrease fatigue. By contrast, knowledge on the prevalence of micronutrient deficiencies and the possible effects of nutritional interventions in PAH patients is limited. Although data on nutritional status and micronutrient deficiencies in PAH are scarce, the available knowledge, including that from adjacent fields, suggests that nutritional intervention to correct deficiencies and metabolic alterations may contribute to a reduction of disease burden.

The effects of in-flight treadmill exercise on postflight orthostatic tolerance

NASA Technical Reports Server (NTRS)

Siconolfi, Steven F.; Charles, John B.

1992-01-01

In-flight aerobic exercise is thought to decrease the deconditioning effects of microgravity. Two deconditioning characteristics are the decreases in aerobic capacity (maximum O2 uptake) and an increased cardiovascular response to orthostatic stress (supine to standing). Changes in both parameters were examined after Shuttle flights of 8 to 11 days in astronauts who performed no in-flight exercise, a lower than normal volume of exercise, and a near-normal volume of exercise. The exercise regimen was a traditional continuous protocol. Maximum O2 uptake was maintained in astronauts who completed a near-normal exercise volume of in-flight exercise. Cardiovascular responses to stand test were equivocal among the groups. The use of the traditional exercise regimen as a means to maintain adequate orthostatic responses produced equivocal responses. A different exercise prescription may be more effective in maintaining both exercise capacity and orthostatic tolerance.

Tailored cognitive-behavioural therapy and exercise training improves the physical fitness of patients with fibromyalgia.

PubMed

van Koulil, S; van Lankveld, W; Kraaimaat, F W; van Helmond, T; Vedder, A; van Hoorn, H; Donders, A R T; Wirken, L; Cats, H; van Riel, P L C M; Evers, A W M

2011-12-01

Patients with fibromyalgia have diminished levels of physical fitness, which may lead to functional disability and exacerbating complaints. Multidisciplinary treatment comprising cognitive-behavioural therapy (CBT) and exercise training has been shown to be effective in improving physical fitness. However, due to the high drop-out rates and large variability in patients' functioning, it was proposed that a tailored treatment approach might yield more promising treatment outcomes. High-risk fibromyalgia patients were randomly assigned to a waiting list control group (WLC) or a treatment condition (TC), with the treatment consisting of 16 twice-weekly sessions of CBT and exercise training tailored to the patient's cognitive-behavioural pattern. Physical fitness was assessed with two physical tests before and 3 months after treatment and at corresponding intervals in the WLC. Treatment effects were evaluated using linear mixed models. The level of physical fitness had improved significantly in the TC compared with the WLC. Attrition rates were low, effect sizes large and reliable change indices indicated a clinically relevant improvement among the TC. A tailored multidisciplinary treatment approach for fibromyalgia consisting of CBT and exercise training is well tolerated, yields clinically relevant changes, and appears a promising approach to improve patients' physical fitness. ClinicalTrials.gov ID NCT00268606.

Autophagy activation, not peroxisome proliferator-activated receptor γ coactivator 1α, may mediate exercise-induced improvements in glucose handling during diet-induced obesity.

PubMed

Rosa-Caldwell, Megan E; Brown, Jacob L; Lee, David E; Blackwell, Thomas A; Turner, Kyle W; Brown, Lemuel A; Perry, Richard A; Haynie, Wesley S; Washington, Tyrone A; Greene, Nicholas P

2017-09-01

What is the central question of this study? What are the individual and combined effects of muscle-specific peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α) overexpression and physical activity during high-fat feeding on glucose and exercise tolerance? What is the main finding and its importance? Our main finding is that muscle-specific PGC-1α overexpression provides no protection against lipid-overload pathologies nor does it enhance exercise adaptations. Instead, physical activity, regardless of PGC-1α content, protects against high-fat diet-induced detriments. Activation of muscle autophagy was correlated with exercise protection, suggesting that autophagy might be a mediating factor for exercise-induced protection from lipid overload. The prevalence of glucose intolerance is alarmingly high. Efforts to promote mitochondrial biogenesis through peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α) to mitigate glucose intolerance have been controversial. However, physical activity remains a primary means to alleviate the condition. The aim of this study was to determine the combined effects of muscle-specific overexpression of PGC-1α and physical activity on glucose handling during diet-induced obesity. Wild-type (WT, ∼20) and PGC-1α muscle transgenic (MCK-PGC-1α, ∼20) mice were given a Western diet (WD) at 8 weeks age and allowed to consume food ab libitum throughout the study. At 12 weeks of age, all animals were divided into sedentary (SED) or voluntary wheel running (VWR) interventions. At 7, 11 and 15 weeks of age, animals underwent glucose tolerance tests (GTT) and graded exercise tests (GXT). At 16 weeks of age, tissues were collected. At 11 weeks, the MCK-PGC-1α animals had 50% greater glucose tolerance integrated area under the curve compared with WT. However, at 15 weeks, SED animals also had greater GTT integrated area under the curve compared with VWR, regardless of genotype; furthermore, SED animals demonstrated reduced exercise capacity compared with earlier time points, which was not seen in VWR animals. Voluntary distance run per day was correlated with GTT in VWR-WT, but not VWR-MCK-PGC-1α mice. Voluntary wheel running and genotype independently resulted in a greater LC3II/LC3I ratio, suggesting enhanced autophagosome formation, which was correlated with exercise-induced improvements in GTT. In conclusion, artificially increasing mitochondrial content does not protect from lipid-induced pathologies nor does it augment exercise adaptations. Physical activity ameliorates the effects of lipid overload-induced glucose intolerance, an effect that appears to be related to enhanced activation of autophagy. © 2017 The Authors. Experimental Physiology © 2017 The Physiological Society.

Baseline severity but not gender modulates quantified Crataegus extract effects in early heart failure--a pooled analysis of clinical trials.

PubMed

Eggeling, Thomas; Regitz-Zagrosek, Vera; Zimmermann, Andrea; Burkart, Martin

2011-11-15

The efficacy of quantified Crataegus extract in chronic heart failure (CHF) has been assessed in numerous clinical studies. The present pooled analysis evaluates the impact of baseline severity and gender on objective and patient-reported endpoints and associations between both types of outcomes in patients with early CHF. Available data from 687 individual patients treated with quantified Crataegus extract or placebo in ten studies were pooled. Treatment effects on physiologic outcome parameters and on symptoms were analysed for their association with baseline severity and gender. Changes in symptom scores were investigated with respect to their relation to physiologic outcome parameters. Results were compared with observations in a 3-year cohort study. Physiologic outcome parameters maximal workload (MWL), left ventricular ejection fraction (LVEF) and pressure-heart rate product increase (PHRPI) at 50 W ergometric exercise improved more in active treatment than in placebo patients. Magnitude of improvement was independent from baseline for LVEF but increased for MWL and PHRPI with baseline severity. Improvement of typical symptoms like reduced exercise tolerance, exertional dyspnea, weakness, fatigue, and palpitations improved more with active treatment and in patients with more severe symptoms. A weak association between improvements in MWL, PRHP, and symptoms could be demonstrated. Gender differences in treatment effects could be explained by baseline differences. Results of the pooled analysis are in agreement with observations in the cohort study. Crataegus extract treatment effects on physiologic outcomes and typical symptoms were modulated by baseline severity. Taking baseline differences into account, benefits were comparable in male and female patients with impaired exercise-tolerance in early chronic heart-failure. Copyright © 2011 Elsevier GmbH. All rights reserved.

Clinical application of ghrelin for chronic respiratory failure.

PubMed

Matsumoto, Nobuhiro; Tsubouchi, Hironobu; Imazu, Yoshifumi; Arimura, Yasuji; Yanagi, Shigehisa; Iiboshi, Hirotoshi; Nakazato, Masamitsu

2017-01-01

Chronic respiratory failure, which is often caused by chronic obstructive pulmonary disease, chronic lower respiratory tract infection, or interstitial pneumonia, often leads to cachexia with disease progression. Patients who have chronic respiratory failure with cachexia exhibit increased morbidity. Although cachectic status is an important clinical problem, there are no effective therapies for cachexia. Ghrelin has various effects, including increasing food intake, attenuating sympathetic nerve activity, inhibiting inflammation, increasing cardiac output, and controlling fat utilization. These effects of ghrelin are ideal targets for the treatment of severely wasting chronic respiratory disease. In a few clinical studies, including a small randomized controlled trial, ghrelin administration to cachectic patients with chronic respiratory failure improved exercise tolerance, dyspnea, and appetite. The patients in these studies gained muscle mass and weight. In another study of chronic lower respiratory tract infection with cachexia, ghrelin suppressed airway inflammation by decreasing neutrophil accumulation in the airway, resulting in improvements in oxygenation and exercise tolerance. Although further clinical investigations are needed to clarify its usefulness, ghrelin is expected to become a novel therapy for cachectic patients with chronic respiratory failure.

Exercise for haemophilia.

PubMed

Strike, Karen; Mulder, Kathy; Michael, Rojer

2016-12-19

Haemophilia is a bleeding disorder associated with haemorrhaging into joints and muscles. Exercise is often used to aid recovery after bleeds, and to improve joint function in the presence of arthropathy. Our objective was to systematically review the available evidence on the safety and effectiveness of exercise for people with haemophilia. We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Coagulopathies Trials Register and electronic databases PubMed, OVID-Embase, and CINAHL. We hand searched abstracts from congresses of the World Federation of Hemophilia and the European Hematology Association, trial registries and the reference lists of relevant articles.Date of the last search of the Cochrane Cystic Fibrosis and Genetic Disorders Group's Coagulopathies Trials Register: 14 December 2016. Randomized or quasi-randomized controlled studies comparing any exercise intervention considered relevant in haemophilia management including supervised, unsupervised, aquatic, strengthening, aerobic or cardiovascular, stretching, proprioceptive and balance training exercise programs in males of any age with haemophilia A or B of any severity (those with co-morbidities were not excluded). Two authors reviewed the identified abstracts to determine their eligibility. For studies meeting the inclusion criteria, full articles were obtained. The two authors extracted data and assessed the risk of bias. Any disagreements were resolved by discussion. The authors contacted study investigators to obtain any missing data. Eight studies were included, which represented 233 males with all severities of haemophilia A and B, ranging in age from eight years to 49 years. Study duration ranged from four to 12 weeks. Exercise interventions varied greatly and included resistance exercises, isometric exercises, bicycle ergometry, treadmill walking and hydrotherapy; therefore, comparison between studies was difficult.None of the studies measured or reported adverse effects from the interventions. None of the studies reported outcomes regarding bleed frequency, quality of life or aerobic activity. Overall risk of bias across all studies was assessed as unclear.Very few studies provided sufficient information for comparison. None of the studies reported data that favoured the control group. One study reported that six weeks of resistance training improved joint health status (Colorado score) compared to controls. The addition of pulsed electromagnetic fields also improved ankle scores compared to exercises alone, but this was not seen in the elbows or knees.Two studies reported statistically significant improvements in pain intensity after exercise interventions compared to controls. Hydrotherapy exercises produced significant decreases in pain compared to controls and land-based exercise groups.Two studies found improvement in joint motion in the exercise group compared to controls. One study compared land- and water-based exercises; there was no difference in the range of motion between the two groups; however, the water-based exercise group did show improvement over the control group.One study, comparing joint traction and proprioceptive neuromuscular facilitation for the elbow to a control group, showed no differences in biceps girth or strength after 12 weeks of intervention.Some studies reported comparisons between interventions. In one study, treadmill training significantly improved balance in children compared to bicycle ergometry. Another study added partial weight bearing exercises to quadriceps exercises and showed improved walking tolerance.Four studies evaluated quadriceps or hamstring strength (or both). The addition of bicycle ergometry and exercises with weights was more effective than static exercises and treadmill walking for strengthening knee flexors and extensors. Partial weight-bearing exercises through range were more effective than static and short arc exercises for improving knee extensor strength. The addition of treadmill walking to ultrasound, stretching and strengthening exercises showed increased peak torque of knee flexors and extensors and decrease in knee effusion.The results should be interpreted with caution due to the quality of evidence (GRADE) as outlined in the summary of findings tables, which demonstrates that all but one of the outcomes assessed were rated as low or very low due to the small sample sizes and potential bias. These results must be considered with caution. There is a lack of confidence in the results due to the small number of included studies and the inability to pool the results due to the heterogeneity of outcome measures. Most exercise interventions produced improvement in one or more of the measured outcomes including pain, range of motion, strength and walking tolerance. Hydrotherapy may be more effective than land exercises for pain relief in adults. Functional exercises such as treadmill walking and partial weight bearing exercises seem to be more effective than static or short arc exercises for improving muscle strength. These findings are consistent with the many non-controlled intervention reports in the haemophilia literature. No adverse effects were reported as a result of any of the interventions. However, some groups used prophylactic factor prior to exercise and other groups studied only subjects with moderate haemophilia. Therefore, the safety of these techniques for persons with severe haemophilia remains unclear.

Effects of Weight Loss with and without Exercise on Regional Body Fat Distribution in Postmenopausal Women.

PubMed

Serra, Monica C; Blumenthal, Jacob B; Addison, Odessa R; Miller, Ann J; Goldberg, Andrew P; Ryan, Alice S

2017-01-01

The purpose was to determine whether lifestyle interventions have different effects on regional fat in women with normal glucose tolerance vs. impaired glucose tolerance (NGT vs. IGT). Changes in glucose metabolism (2-h oral glucose-tolerance tests), android to gynoid fat mass ratio (dual energy X-ray absorptiometry [DXA]), visceral to subcutaneous abdominal fat area ratio (CT), and abdominal to gluteal subcutaneous fat cell weight (FCW; adipose tissue biopsies) were determined in 60 overweight postmenopausal women (45-80 years) following 6 months of weight loss alone (WL; n = 28) or with aerobic exercise (AEX + WL; n = 32). The interventions led to ∼8% decrease in weight, but only the AEX + WL group improved fitness (↑11% in VO2max) and reduced the android-to-gynoid fat mass ratio (↓5%; p < 0.05). Both NGT and IGT groups reduced visceral and subcutaneous abdominal fat areas and abdominal and gluteal FCWs, which related to improvements in homeostatic model assessment (r = 0.34-0.42) and 2-h glucose (r = 0.34-0.35), respectively (p < 0.05). The decline in FCW was 2× greater in women with IGT following WL (p < 0.05). The ratios of abdominal-to-gluteal FCW did not change following either intervention. The mechanisms by which WL with and without exercise impact regional fat loss should be explored as reductions in abdominal fat area and subcutaneous FCW appear to influence glucose metabolism. This is a work of the U.S. Government and is not subject to copyright protection in the United States. Foreign copyrights may apply. Published by S. Karger AG, Basel.

Voluntary Exercise Improves Estrous Cyclicity in Prenatally Androgenized Female Mice Despite Programming Decreased Voluntary Exercise: Implications for Polycystic Ovary Syndrome (PCOS).

PubMed

Homa, Lori D; Burger, Laura L; Cuttitta, Ashley J; Michele, Daniel E; Moenter, Suzanne M

2015-12-01

Prenatal androgen (PNA) exposure in mice produces a phenotype resembling lean polycystic ovary syndrome. We studied effects of voluntary exercise on metabolic and reproductive parameters in PNA vs vehicle (VEH)-treated mice. Mice (8 wk of age) were housed individually and estrous cycles monitored. At 10 weeks of age, mice were divided into groups (PNA, PNA-run, VEH, VEH-run, n = 8-9/group); those in the running groups received wheels allowing voluntary running. Unexpectedly, PNA mice ran less distance than VEH mice; ovariectomy eliminated this difference. In ovary-intact mice, there was no difference in glucose tolerance, lower limb muscle fiber types, weight, or body composition among groups after 16 weeks of running, although some mitochondrial proteins were mildly up-regulated by exercise in PNA mice. Before running, estrous cycles in PNA mice were disrupted with most days in diestrus. There was no change in cycles during weeks 1-6 of running (10-15 wk of age). In contrast, from weeks 11 to 16 of running, cycles in PNA mice improved with more days in proestrus and estrus and fewer in diestrus. PNA programs reduced voluntary exercise, perhaps mediated in part by ovarian secretions. Exercise without weight loss improved estrous cycles, which if translated could be important for fertility in and counseling of lean women with polycystic ovary syndrome.

High- and moderate-intensity training normalizes ventricular function and mechanoenergetics in mice with diet-induced obesity.

PubMed

Hafstad, Anne D; Lund, Jim; Hadler-Olsen, Elin; Höper, Anje C; Larsen, Terje S; Aasum, Ellen

2013-07-01

Although exercise reduces several cardiovascular risk factors associated with obesity/diabetes, the metabolic effects of exercise on the heart are not well-known. This study was designed to investigate whether high-intensity interval training (HIT) is superior to moderate-intensity training (MIT) in counteracting obesity-induced impairment of left ventricular (LV) mechanoenergetics and function. C57BL/6J mice with diet-induced obesity (DIO mice) displaying a cardiac phenotype with altered substrate utilization and impaired mechanoenergetics were subjected to a sedentary lifestyle or 8-10 weeks of isocaloric HIT or MIT. Although both modes of exercise equally improved aerobic capacity and reduced obesity, only HIT improved glucose tolerance. Hearts from sedentary DIO mice developed concentric LV remodeling with diastolic and systolic dysfunction, which was prevented by both HIT and MIT. Both modes of exercise also normalized LV mechanical efficiency and mechanoenergetics. These changes were associated with altered myocardial substrate utilization and improved mitochondrial capacity and efficiency, as well as reduced oxidative stress, fibrosis, and intracellular matrix metalloproteinase 2 content. As both modes of exercise equally ameliorated the development of diabetic cardiomyopathy by preventing LV remodeling and mechanoenergetic impairment, this study advocates the therapeutic potential of physical activity in obesity-related cardiac disorders.

High- and Moderate-Intensity Training Normalizes Ventricular Function and Mechanoenergetics in Mice With Diet-Induced Obesity

PubMed Central

Hafstad, Anne D.; Lund, Jim; Hadler-Olsen, Elin; Höper, Anje C.; Larsen, Terje S.; Aasum, Ellen

2013-01-01

Although exercise reduces several cardiovascular risk factors associated with obesity/diabetes, the metabolic effects of exercise on the heart are not well-known. This study was designed to investigate whether high-intensity interval training (HIT) is superior to moderate-intensity training (MIT) in counteracting obesity-induced impairment of left ventricular (LV) mechanoenergetics and function. C57BL/6J mice with diet-induced obesity (DIO mice) displaying a cardiac phenotype with altered substrate utilization and impaired mechanoenergetics were subjected to a sedentary lifestyle or 8–10 weeks of isocaloric HIT or MIT. Although both modes of exercise equally improved aerobic capacity and reduced obesity, only HIT improved glucose tolerance. Hearts from sedentary DIO mice developed concentric LV remodeling with diastolic and systolic dysfunction, which was prevented by both HIT and MIT. Both modes of exercise also normalized LV mechanical efficiency and mechanoenergetics. These changes were associated with altered myocardial substrate utilization and improved mitochondrial capacity and efficiency, as well as reduced oxidative stress, fibrosis, and intracellular matrix metalloproteinase 2 content. As both modes of exercise equally ameliorated the development of diabetic cardiomyopathy by preventing LV remodeling and mechanoenergetic impairment, this study advocates the therapeutic potential of physical activity in obesity-related cardiac disorders. PMID:23493573

Battling insulin resistance in elderly obese people with type 2 diabetes: bring on the heavy weights.

PubMed

Willey, Karen A; Singh, Maria A Fiatarone

2003-05-01

Exercise improves insulin resistance and has beneficial effects in preventing and treating type 2 diabetes. However, aerobic exercise is hindered in many type 2 diabetic patients because of advancing age, obesity, and other comorbid conditions. Weight lifting or progressive resistance training (PRT) offers a safe and effective exercise alternative for these people. PRT promotes favorable energy balance and reduced visceral fat deposition through enhanced basal metabolism and activity levels while counteracting age- and disease-related muscle wasting. PRT improves insulin sensitivity and glycemic control; increases muscle mass, strength, and endurance; and has positive effects on bone density, osteoarthritic symptoms, mobility impairment, self-efficacy, hypertension, and lipid profiles. PRT also alleviates symptoms of anxiety, depression, and insomnia in individuals with clinical depression and improves exercise tolerance in individuals with cardiac ischemic disease and congestive heart failure; all of these aspects are relevant to the care of diabetic elders. Moreover, PRT is safe and well accepted in many complex patient populations, including very frail elderly individuals and those with cardiovascular disease. The greater feasibility of using PRT over aerobic exercise in elderly obese type 2 diabetic individuals because of concomitant cardiovascular, arthritic, and other disease provides a solid rationale for investigating the global benefits of PRT in the management of diabetes.

Non-invasive assessment of respiratory muscle function and its relationship to exercise tolerance in patients with chronic obstructive pulmonary disease.

PubMed

Chlumský, J; Filipova, P; Terl, M

2006-01-01

Most patients with chronic obstructive pulmonary disease (COPD) have impaired respiratory muscle function. Maximal oesophageal pressure correlates closely with exercise tolerance and seems to predict the distance walked during the 6-min walk test. This study assessed the non-invasive parameters of respiratory muscle function in 41 patients with COPD to investigate their relationship to pulmonary function tests and exercise tolerance. The COPD patients, who demonstrated the full range of airway obstruction severity, had a mean forced expiratory volume in 1 s of 42.5% predicted (range, 20 - 79% predicted). Both the maximal inspiratory muscle strength and non-invasive tension-time index were significantly correlated with the degree of lung hyperinflation, as expressed by the ratio of residual volume to total lung capacity, and the distance walked in 6 min. We conclude that respiratory muscle function was influenced mainly by lung hyperinflation and that it had an important effect on exercise tolerance in COPD patients.

Adaptation to heat and exercise performance under cooler conditions: a new hot topic.

PubMed

Corbett, Jo; Neal, Rebecca A; Lunt, Heather C; Tipton, Michael J

2014-10-01

Chronic exposure to a stressor elicits adaptations enhancing the tolerance to that stressor. These adaptive responses might also improve tolerance under less stressful conditions. For example, historically there has been much interest in the adaptive responses to high-altitude, or hypoxia, and their ergogenic potential under sea-level, or normoxic, conditions. In contrast, the influence of the adaptive responses to heat on exercise under cooler conditions has received relatively little interest. Heat acclimation/acclimatization (HA) is known to increase work capacity in hot environments. Yet, aerobic exercise performance can progressively deteriorate as ambient temperature increases beyond ~10 °C, indicating a thermal limitation even under relatively cool conditions. The improved thermoregulatory capability induced by HA might attenuate this thermal decrement in a manner similar to that seen when exposed to hotter temperatures. Moreover, the suite of adaptations elicited by HA has the potential to increase maximal oxygen uptake, lactate threshold and economy, and thus may be ergogenic even under conditions where performance is not thermally limited. Indeed, evidence is now emerging to support an ergogenic effect of HA but the number of studies is limited and in some instances lack appropriate control, are confounded by methodological limitations, or do not address the mechanisms of action. Nevertheless, these tantalising insights into the ergogenic potential of heat will likely generate considerable interest in this new 'hot topic'. Future research will need to employ well-designed studies to clarify the exercise conditions under which ergogenic effects of HA are apparent, to elucidate the precise mechanisms, and to optimise HA strategies for performance.

Exercise training reverses the negative effects of chronic L-arginine supplementation on insulin sensitivity.

PubMed

Salgueiro, Rafael Barrera; Gerlinger-Romero, Frederico; Guimarães-Ferreira, Lucas; de Castro Barbosa, Thais; Nunes, Maria Tereza

2017-12-15

L-Arginine has emerged as an important supplement for athletes and non-athletes in order to improve performance. Arginine has been extensively used as substrate for nitric oxide synthesis, leading to increased vasodilatation and hormonal secretion. However, the chronic consumption of arginine has been shown to impair insulin sensitivity. In the present study, we aimed to evaluate whether chronic arginine supplementation associated with exercise training would have a beneficial impact on insulin sensitivity. We, therefore, treated Wistar rats for 4weeks with arginine, associated or not with exercise training (treadmill). We assessed the somatotropic activation, by evaluating growth hormone (GH) gene expression and protein content in the pituitary, as well is GH concentration in the serum. Additionally, we evaluate whole-body insulin sensitivity, by performing an insulin tolerance test. Skeletal muscle morpho-physiological parameters were also assessed. Insulin sensitivity was impaired in the arginine-treated rats. However, exercise training reversed the negative effects of arginine. Arginine and exercise training increased somatotropic axis function, muscle mass and body weight gain. The combination arginine and exercise training further decreased total fat mass. Our results confirm that chronic arginine supplementation leads to insulin resistance, which can be reversed in the association with exercise training. We provide further evidence that exercise training is an important tool to improve whole-body metabolism. Copyright © 2017 Elsevier Inc. All rights reserved.

Anabolic steroid and gender-dependent modulation of cytosolic HSP70s in fast- and slow-twitch skeletal muscle.

PubMed

González, B; Hernando, R; Manso, R

2000-09-01

Besides their clinical uses, anabolic steroids (AASs) are self-administered by athletes to improve muscle mass and sports performance. The biological basis for their presumed effectiveness at suprapharmacological doses, however, remains uncertain. Since the expression of high levels of some stress proteins (HSPs) has been associated with an increased tolerance to stress and chronic exercise up-regulates HSP72 in skeletal muscle, this investigation was aimed at testing whether the administration of suprapharmacological doses of AASs, either alone or in conjunction with chronic exercise, induced changes in HSP72. Nandrolone decanoate (ND), an estrene derivative, but not stanozolol (ST), a derivative of the androstane series, up-regulated the levels of HSP72 and changed the proportions of various charge variants of the cytosolic HSP70s in sedentary and exercise-trained rats, exclusively in fast-twitch fibres. Since the expression of HSP73-levels in skeletal muscle was dependent on gender but not on muscle type, and that of HSP72-levels was muscle type specific but gender-independent, ND effects on cytosolic HSP70s could not be explained solely by a functional relationship with sex steroids. The reported results indicate that, by up-regulating the expression levels of HSP72 in fast-twitch fibres, nandrolone decanoate could contribute to improving the tolerance of skeletal muscle to high-intensity training.

Effects of pitavastatin on walking capacity and CD34+/133+ cell number in patients with peripheral artery disease.

PubMed

Arao, Kenshiro; Yasu, Takanori; Endo, Yasuhiro; Funazaki, Toshikazu; Ota, Yoshimi; Shimada, Kazunori; Tokutake, Eiichi; Naito, Naoki; Takase, Bonpei; Wake, Minoru; Ikeda, Nahoko; Horie, Yasuto; Sugimura, Hiroyuki; Momomura, Shin-Ichi; Kawakami, Masanobu

2017-10-01

This multi-center prospective non-randomized comparative study investigated the effects of pitavastatin in patients with peripheral artery disease (PAD) in terms of exercise tolerance capacities and peripheral CD34 + /133 + cell numbers. At baseline, a peripheral blood test was administered to 75 patients with PAD, along with a treadmill exercise test using the Skinner-Gardner protocol to measure asymptomatic walking distance (AWD) and maximum walking distance (MWD). Each patient was assigned to a 6-month pitavastatin treatment group (n = 53) or a control group (n = 22), according to the patient's preference. The tests were repeated in both groups at 3 and 6 months. Baseline AWD and MWD correlated positively with the ankle-brachial pressure index (r = 0.342, p = 0.0032 and r = 0.324, p = 0.0054, respectively). Both AWD and MWD values improved at 3 and 6 months compared with baseline, and the degrees of their improvement were higher in the pitavastatin treatment group. CD34 + /133 + cell numbers did not change over time or between groups. Eighty-seven percent of patients in the treatment group attained low-density lipoprotein cholesterol levels below 100 mg/dL after 3 months. The study shows that pitavastatin may be effective in increasing exercise tolerance capacity in patients with PAD.

Improved Inflammatory Balance of Human Skeletal Muscle during Exercise after Supplementations of the Ginseng-Based Steroid Rg1

PubMed Central

Hou, Chien-Wen; Lee, Shin-Da; Kao, Chung-Lan; Cheng, I-Shiung; Lin, Yu-Nan; Chuang, Sheng-Ju; Chen, Chung-Yu; Ivy, John L.; Huang, Chih-Yang; Kuo, Chia-Hua

2015-01-01

The purpose of the study was to determine the effect of ginseng-based steroid Rg1 on TNF-alpha and IL-10 gene expression in human skeletal muscle against exercise challenge, as well as on its ergogenic outcomes. Randomized double-blind placebo-controlled crossover trials were performed, separated by a 4-week washout. Healthy young men were randomized into two groups and received capsule containing either 5 mg of Rg1 or Placebo one night and one hour before exercise. Muscle biopsies were conducted at baseline, immediately and 3 h after a standardized 60-min cycle ergometer exercise. While treatment differences in glycogen depletion rate of biopsied quadriceps muscle during exercise did not reach statistical significance, Rg1 supplementations enhanced post-exercise glycogen replenishment and increased citrate synthase activity in the skeletal muscle 3 h after exercise, concurrent with improved meal tolerance during recovery (P<0.05). Rg1 suppressed the exercise-induced increases in thiobarbituric acids reactive substance (TBARS) and reversed the increased TNF-alpha and decreased IL-10 mRNA of quadriceps muscle against the exercise challenge. PGC-1 alpha and GLUT4 mRNAs of exercised muscle were not affected by Rg1. Maximal aerobic capacity (VO2max) was not changed by Rg1. However, cycling time to exhaustion at 80% VO2max increased significantly by ~20% (P<0.05). Conclusion: Our result suggests that Rg1 is an ergogenic component of ginseng, which can minimize unwanted lipid peroxidation of exercised human skeletal muscle, and attenuate pro-inflammatory shift under exercise challenge. PMID:25617625

Improved inflammatory balance of human skeletal muscle during exercise after supplementations of the ginseng-based steroid Rg1.

PubMed

Hou, Chien-Wen; Lee, Shin-Da; Kao, Chung-Lan; Cheng, I-Shiung; Lin, Yu-Nan; Chuang, Sheng-Ju; Chen, Chung-Yu; Ivy, John L; Huang, Chih-Yang; Kuo, Chia-Hua

2015-01-01

The purpose of the study was to determine the effect of ginseng-based steroid Rg1 on TNF-alpha and IL-10 gene expression in human skeletal muscle against exercise challenge, as well as on its ergogenic outcomes. Randomized double-blind placebo-controlled crossover trials were performed, separated by a 4-week washout. Healthy young men were randomized into two groups and received capsule containing either 5 mg of Rg1 or Placebo one night and one hour before exercise. Muscle biopsies were conducted at baseline, immediately and 3 h after a standardized 60-min cycle ergometer exercise. While treatment differences in glycogen depletion rate of biopsied quadriceps muscle during exercise did not reach statistical significance, Rg1 supplementations enhanced post-exercise glycogen replenishment and increased citrate synthase activity in the skeletal muscle 3 h after exercise, concurrent with improved meal tolerance during recovery (P<0.05). Rg1 suppressed the exercise-induced increases in thiobarbituric acids reactive substance (TBARS) and reversed the increased TNF-alpha and decreased IL-10 mRNA of quadriceps muscle against the exercise challenge. PGC-1 alpha and GLUT4 mRNAs of exercised muscle were not affected by Rg1. Maximal aerobic capacity (VO2max) was not changed by Rg1. However, cycling time to exhaustion at 80% VO2max increased significantly by ~20% (P<0.05). Our result suggests that Rg1 is an ergogenic component of ginseng, which can minimize unwanted lipid peroxidation of exercised human skeletal muscle, and attenuate pro-inflammatory shift under exercise challenge.

The Effectiveness of Lifestyle Adaptation for the Prevention of Prediabetes in Adults: A Systematic Review

PubMed Central

Kerrison, George; Gillis, Richard B.; Jiwani, Shahwar I.; Alzahrani, Qushmua; Kok, Samil; Harding, Stephen E.; Shaw, Ian

2017-01-01

Diabetes prevalence is increasing exceptionally worldwide and with this come associated healthcare costs. The primary outcome of this systematic review was to assess glycaemic control and incidence of Type 2 diabetes mellitus (T2DM) diagnosis after exercise and dietary intervention (measured with any validated scale). The secondary outcome assessed body mass index change, weight change, and physical exercise capacity after diet and exercise intervention (measured with any validated scale). 1,780 studies were identified from searching electronic databases. Relevant studies went through a selection process. The inclusion criteria for all studies were people with prediabetes diagnosed by either impaired glucose tolerance (IGT) or impaired fasting glucose (IFG). Lifestyle adaptation reduced the incidence of diabetes development more than standard treatment. Furthermore, better glycaemic control, improved physical exercise capacity, and increased weight reduction were observed with lifestyle intervention over standard treatment. Finally, improvements over the long term deteriorated, highlighting problems with long-term adherence to lifestyle changes. Overall, cumulative incidence of diabetes is drastically reduced in the intervention groups compared to control groups (standard care). Furthermore, glycaemic control was improved in the short term, with many participants reverting to normoglycaemia. PMID:28567425

The Effectiveness of Lifestyle Adaptation for the Prevention of Prediabetes in Adults: A Systematic Review.

PubMed

Kerrison, George; Gillis, Richard B; Jiwani, Shahwar I; Alzahrani, Qushmua; Kok, Samil; Harding, Stephen E; Shaw, Ian; Adams, Gary G

2017-01-01

Diabetes prevalence is increasing exceptionally worldwide and with this come associated healthcare costs. The primary outcome of this systematic review was to assess glycaemic control and incidence of Type 2 diabetes mellitus (T2DM) diagnosis after exercise and dietary intervention (measured with any validated scale). The secondary outcome assessed body mass index change, weight change, and physical exercise capacity after diet and exercise intervention (measured with any validated scale). 1,780 studies were identified from searching electronic databases. Relevant studies went through a selection process. The inclusion criteria for all studies were people with prediabetes diagnosed by either impaired glucose tolerance (IGT) or impaired fasting glucose (IFG). Lifestyle adaptation reduced the incidence of diabetes development more than standard treatment. Furthermore, better glycaemic control, improved physical exercise capacity, and increased weight reduction were observed with lifestyle intervention over standard treatment. Finally, improvements over the long term deteriorated, highlighting problems with long-term adherence to lifestyle changes. Overall, cumulative incidence of diabetes is drastically reduced in the intervention groups compared to control groups (standard care). Furthermore, glycaemic control was improved in the short term, with many participants reverting to normoglycaemia.

Interactive videogame as rehabilitation tool of patients with chronic respiratory diseases: preliminary results of a feasibility study.

PubMed

Mazzoleni, Stefano; Montagnani, Giulia; Vagheggini, Guido; Buono, Lorenzo; Moretti, Francesca; Dario, Paolo; Ambrosino, Nicolino

2014-10-01

To evaluate the effectiveness of an interactive videogame (IV) system in addition to a supervised pulmonary rehabilitation programme (PRP) in patients with chronic respiratory diseases. Randomised Controlled Trial comparing standard PRP (20 patients, control group: CG), and PRP + sessions of interactive videogame-aided exercises (20 patients, experimental group: EG). Lung and respiratory muscle function, arterial blood gases, exercise capacity, dyspnoea, health status and health-related quality of life (HRQL) and emotional response were measured before and after PRP. A questionnaire on acceptability of the PRP was administered. Exercise capacity, dyspnoea and HRQL significantly improved in both groups after the PRP, whereas the EG showed a greater improvement in six-minute walk test and transitional dyspnoea index than the CG. No difference in psychological status or acceptability of PRP was observed between the two groups. The addition of IV training was more effective for improving some parameters of exercise tolerance and dyspnoea, although did not result in better psychological status nor it was better accepted than the standard PRP in patients with chronic respiratory diseases. Copyright © 2014 Elsevier Ltd. All rights reserved.

Impact of exercise on diurnal and nocturnal markers of glycaemic variability and oxidative stress in obese individuals with type 2 diabetes or impaired glucose tolerance.

PubMed

Farabi, Sarah S; Carley, David W; Smith, Donald; Quinn, Lauretta

2015-09-01

We measured the effects of a single bout of exercise on diurnal and nocturnal oxidative stress and glycaemic variability in obese subjects with type 2 diabetes mellitus or impaired glucose tolerance versus obese healthy controls. Subjects (in random order) performed either a single 30-min bout of moderate-intensity exercise or remained sedentary for 30 min at two separate visits. To quantify glycaemic variability, standard deviation of glucose (measured by continuous glucose monitoring system) and continuous overlapping net glycaemic action of 1-h intervals (CONGA-1) were calculated for three 12-h intervals during each visit. Oxidative stress was measured by 15-isoprostane F(2t) levels in urine collections for matching 12-h intervals. Exercise reduced daytime glycaemic variability (ΔCONGA-1 = -12.62 ± 5.31 mg/dL, p = 0.04) and urinary isoprostanes (ΔCONGA-1 = -0.26 ± 0.12 ng/mg, p = 0.04) in the type 2 diabetes mellitus/impaired glucose tolerance group. Daytime exercise-induced change in urinary 15-isoprostane F(2t) was significantly correlated with both daytime standard deviation (r = 0.68, p = 0.03) and with subsequent overnight standard deviation (r = 0.73, p = 0.027) in the type 2 diabetes mellitus/impaired glucose tolerance group. Exercise significantly impacts the relationship between diurnal oxidative stress and nocturnal glycaemic variability in individuals with type 2 diabetes mellitus/impaired glucose tolerance. © The Author(s) 2015.

NASA's Functional Task Test: High Intensity Exercise Improves the Heart Rate Response to a Stand Test Following 70 Days of Bedrest

NASA Technical Reports Server (NTRS)

Laurie, Steven S.; Lee, Stuart M. C.; Phillips, Tiffany R.; Dillon, E. Lichar; Sheffield-Moore, Melinda; Urban, Randall J.; Ploutz-Snyder, Lori; Stenger, Michael B.; Bloomberg, Jacob J.

2015-01-01

Cardiovascular adaptations due to spaceflight are modeled with 6deg head-down tilt bed rest (BR) and result in decreased orthostatic tolerance. We investigated if high-intensity resistive and aerobic exercise with and without testosterone supplementation would improve the heart rate (HR) response to a 3.5-min stand test and how quickly these changes recovered following BR. During 70 days of BR male subjects performed no exercise (Control, n=10), high intensity supine resistive and aerobic exercise (Exercise, n=9), or supine exercise plus supplemental testosterone (Exercise+T, n=8; 100 mg i.m., weekly in 2-week on/off cycles). We measured HR for 2 min while subjects were prone and for 3 min after standing twice before and 0, 1, 6, and 11 days after BR. Mixed-effects linear regression models were used to evaluate group, time, and interaction effects. Compared to pre-bed rest, prone HR was elevated on BR+0 and BR+1 in Control, but not Exercise or Exercise+T groups, and standing HR was greater in all 3 groups. The increase in prone and standing HR in Control subjects was greater than either Exercise or Exercise+T groups and all groups recovered by BR+6. The change in HR from prone to standing more than doubled on BR+0 in all groups, but was significantly less in the Exericse+T group compared to the Control, but not Exercise group. Exercise reduces, but does not prevent the increase in HR observed in response to standing. The significantly lower HR response in the Exercise+T group requires further investigation to determine physiologic significance.

Safe and effective prescription of exercise in acute exacerbations of chronic obstructive pulmonary disease: rationale and methods for an integrated knowledge translation study.

PubMed

Camp, Pat; Reid, W Darlene; Yamabayashi, Cristiane; Brooks, Dina; Goodridge, Donna; Chung, Frank; Marciniuk, Darcy D; Neufeld, Andrea; Hoens, Alsion

2013-01-01

Patients hospitalized with an acute exacerbation of chronic obstructive pulmonary disease (AECOPD) engage in low levels of activity, putting them at risk for relapse and future readmissions. There is little direction for health care providers regarding the parameters for safe exercise during an AECOPD that is effective for increasing activity tolerance before discharge from hospital, especially for patients with associated comorbid conditions. To report the rationale for and methods of a study to develop evidence-informed care recommendations that guide health care providers in the assessment, prescription, monitoring and progression of exercise for patients hospitalized with AECOPD. The present study was a multicomponent knowledge translation project incorporating evidence from systematic reviews of exercise involving populations with chronic obstructive pulmonary disease and⁄or common comorbidities. A Delphi process was then used to obtain expert opinion from clinicians, academics and patients to identify the parameters of safe and effective exercise for patients with AECOPD. Clinical decision-making tool(s) for patients and practitioners supported by a detailed knowledge dissemination, implementation and evaluation framework. The present study addressed an important knowledge gap: the lack of availability of parameters to guide safe and effective exercise prescription for hospitalized patients with AECOPD, with or without comorbid conditions. In the absence of such parameters, health care professionals may adopt an 'activity as tolerated' approach, which may not improve physical activity levels in their patients. The present study synthesizes the best available evidence and expert opinion, and will generate decision-making tools for use by patients and their health care providers.

Baseline regional perfusion impacts exercise response to endobronchial valve therapy in advanced pulmonary emphysema.

PubMed

Argula, Rahul G; Strange, Charlie; Ramakrishnan, Viswanathan; Goldin, Jonathan

2013-11-01

Advanced heterogeneous emphysema with hyperinflation impacts exercise tolerance in COPD. Bronchoscopic lung volume reduction using Zephyr endobronchial valves (EBVs) has been shown to improve lung function in patients with heterogeneous emphysema. It is unclear whether the target lobe perfusion of patients receiving EBV therapy impacts exercise tolerance as measured by the 6-min walk test distance (6MWTD). We performed a retrospective analysis on the treatment group of the Endobronchial Valve for Emphysema Palliation Trial (VENT) to evaluate the impact of perfusion, measured by 99mTc-MAA-perfusion scintigraphy, on the 6-month improvement in 6MWTD. A mixed-model analysis was performed for the treatment outcome, adjusting for other variables such as age, target lobe position, fissure integrity, BMI, sex, destruction score, and lobar exclusion. Dichotomized at the median, of the 169 patients who received EBV therapy, 88 had a low target lobe regional perfusion and 81 had high target lobe regional perfusion at baseline. Patients with a low target lobe regional perfusion had a significant improvement in 6MWTD when compared with those with a high baseline target lobe regional perfusion (30.24 m vs 3.72 m, P = .03). Shifts in perfusion after EBV therapy occurred only in patients with high baseline perfusion and did not correlate with improved 6MWTD. Patients having heterogeneous emphysema with a low baseline target lobe regional perfusion benefit from EBV therapy, independent of the degree of target lobe destruction. This effect is attenuated if the EBV therapy is not occlusive. Characterization of baseline perfusion may enhance clinical results of patients with emphysema undergoing EBV therapy. ClinicalTrials.gov; No.: NCT00000606; URL: www.clincialtrials.gov.

Improvements in insulin sensitivity are blunted by subclinical hypothyroidism.

PubMed

Amati, Francesca; Dubé, John J; Stefanovic-Racic, Maja; Toledo, Frederico G; Goodpaster, Bret H

2009-02-01

Exercise- and weight loss-induced improvements in insulin resistance (IR) are variable; some individuals experience robust enhancements in insulin sensitivity, whereas others do not. Thyroid hormone status is related to IR, but it is not clear whether subclinical hypothyroidism may help to explain the variability in improvements in IR with diet and exercise. The purpose of this study was to examine whether thyroid hormone status is related to the improvement in insulin sensitivity and physical fitness after weight loss and exercise training. By retrospective nested case-control analysis, eight subclinical hypothyroid (sHT) subjects and eight matched euthyroid controls underwent a euglycemic hyperinsulinemic clamp and peak oxygen uptake test, before and after a 16-wk program of moderate aerobic exercise combined with diet-induced weight loss. All subjects were middle-aged (57.3 +/- 3.3 yr), were overweight to obese (body mass index = 33.1 +/- 0.8 kg m(-2)), and had impaired glucose tolerance. The improvement in insulin sensitivity was significantly lower (P < 0.05) in the sHT group than in the euthyroid group. Both groups performed similar amounts of regular exercise and lost a significant amount of body weight during the intervention. VO(2peak) tended to improve in the euthyroid group but not in the sHT group. Subclinical hypothyroidism may interfere with beneficial adaptations on muscle metabolism and physical fitness that typically occur with weight loss and increased physical activity. These results may have significant clinical implications because of the high prevalence of both hypothyroidism and insulin resistance in the aging population.

Four birds with one stone? Reparative, neuroplastic, cardiorespiratory, and metabolic benefits of aerobic exercise poststroke.

PubMed

Ploughman, Michelle; Kelly, Liam P

2016-12-01

Converging evidence from animal models of stroke and clinical trials suggests that aerobic exercise has effects across multiple targets. The subacute phase is characterized by a period of heightened neuroplasticity when aerobic exercise has the potential to optimize recovery. In animals, low intensity aerobic exercise shrinks lesion size and reduces cell death and inflammation, beginning 24 h poststroke. Also in animals, aerobic exercise upregulates brain-derived neurotrophic factor near the lesion and improves learning. In terms of neuroplastic effects, clinical trial results are less convincing and have only examined effects in chronic stroke. Stroke patients demonstrate cardiorespiratory fitness levels below the threshold required to carry out daily activities. This may contribute to a 'neurorehabilitation ceiling' that limits capacity to practice at a high enough frequency and intensity to promote recovery. Aerobic exercise when delivered 2-5 days per week at moderate to high intensity beginning as early as 5 days poststroke improves cardiorespiratory fitness, dyslipidemia, and glucose tolerance. Based on the evidence discussed and applying principles of periodization commonly used to prepare athletes for competition, we have created a model of aerobic training in subacute stroke in which training is delivered in density blocks (duration × intensity) matched to recovery phases.

Myoadenylate deaminase deficiency, hypertrophic cardiomyopathy and gigantism syndrome.

PubMed

Skyllouriotis, M L; Marx, M; Bittner, R E; Skyllouriotis, P; Gross, M; Wimmer, M

1997-07-01

We report a 20-year-old man with gigantism syndrome, hypertrophic cardiomyopathy, muscle weakness, exercise intolerance, and severe psychomotor retardation since childhood. Histochemical and biochemical analysis of skeletal muscle biopsy revealed myoadenylate deaminase deficiency; molecular genetic analysis confirmed the diagnosis of primary (inherited) myoadenylate deaminase deficiency. Plasma, urine, and muscle carnitine concentrations were reduced. L-Carnitine treatment led to gradual improvement in exercise tolerance and cognitive performance; plasma and tissue carnitine levels returned to normal, and echocardiographic evidence of left ventricular hypertrophy disappeared. The combination of inherited myoadenylate deaminase deficiency, gigantism syndrome and carnitine deficiency has not previously been described.

Impact of left ventricular assist device speed adjustment on exercise tolerance and markers of wall stress.

PubMed

Hayward, Christopher S; Salamonsen, Robert; Keogh, Anne M; Woodard, John; Ayre, Peter; Prichard, Roslyn; Kotlyar, Eugene; Macdonald, Peter S; Jansz, Paul; Spratt, Phillip

2015-09-01

Left ventricular assist devices are crucial in rehabilitation of patients with end-stage heart failure. Whether cardiopulmonary function is enhanced with higher pump output is unknown. 10 patients (aged 39±16 years, mean±SD) underwent monitored adjustment of pump speed to determine minimum safe low speed and maximum safe high speed at rest. Patients were then randomized to these speed settings and underwent three 6-minute walk tests (6MWT) and symptom-limited cardiopulmonary stress tests (CPX) on separate days. Pump speed settings (low, normal and high) resulted in significantly different resting pump flows of 4.43±0.6, 5.03±0.94, and 5.72±1.2 l/min (P<.001). There was a significant enhancement of pump flows (greater at higher speed settings) with exercise (P<0.05). Increased pump speed was associated with a trend to increased 6MWT distance (P=.10); and CPX exercise time (p=.27). Maximum workload achieved and peak oxygen consumption were significantly different comparing low to high pump speed settings only (P<.05). N-terminal-pro-B-type natriuretic peptide release was significantly reduced at higher pump speed with exercise (P<.01). We have found that alteration of pump speed setting resulted in significant variation in estimated pump flow. The high-speed setting was associated with lower natriuretic hormone release consistent with lower myocardial wall stress. This did not, however, improve exercise tolerance.

Skeletal muscle neuronal nitric oxide synthase micro protein is reduced in people with impaired glucose homeostasis and is not normalized by exercise training.

PubMed

Bradley, Scott J; Kingwell, Bronwyn A; Canny, Benedict J; McConell, Glenn K

2007-10-01

Skeletal muscle inducible nitric oxide synthase (NOS) protein is greatly elevated in people with type 2 diabetes mellitus, whereas endothelial NOS is at normal levels. Diabetic rat studies suggest that skeletal muscle neuronal NOS (nNOS) micro protein expression may be reduced in human insulin resistance. The aim of this study was to determine whether skeletal muscle nNOSmicro protein expression is reduced in people with impaired glucose homeostasis and whether exercise training increases nNOSmicro protein expression in these individuals because exercise training increases skeletal muscle nNOSmicro protein in rats. Seven people with type 2 diabetes mellitus or prediabetes (impaired fasting glucose and/or impaired glucose tolerance) and 7 matched (sex, age, fitness, body mass index, blood pressure, lipid profile) healthy controls aged 36 to 60 years participated in this study. Vastus lateralis muscle biopsies for nNOSmicro protein determination were obtained, aerobic fitness was measured (peak pulmonary oxygen uptake [Vo(2) peak]), and glucose tolerance and insulin homeostasis were assessed before and after 1 and 4 weeks of cycling exercise training (60% Vo(2) peak, 50 minutes x 5 d wk(-1)). Skeletal muscle nNOSmicro protein was significantly lower (by 32%) in subjects with type 2 diabetes mellitus or prediabetes compared with that in controls before training (17.7 +/- 1.2 vs 26.2 +/- 3.4 arbitrary units, P < .05). The Vo(2) peak and indicators of insulin sensitivity improved with exercise training in both groups (P < .05), but there was no effect of exercise training on skeletal muscle nNOSmicro protein in either group. In conclusion, individuals with impaired glucose homeostasis have reduced skeletal muscle nNOSmicro protein content. However, because exercise training improves insulin sensitivity without influencing skeletal muscle nNOSmicro protein expression, it seems that changes in skeletal muscle nNOSmicro protein are not central to the control of insulin sensitivity in humans and therefore may be a consequence rather than a cause of diabetes.

Perspectives on oral pulmonary hypertension therapies recently approved by the U.S. Food and Drug Administration.

PubMed

Hill, Nicholas S; Badesch, David; Benza, Raymond L; D'Eletto, Thomas A; Farber, Harrison W; Gomberg-Maitland, Mardi; Hassoun, Paul M; Preston, Ioana

2015-02-01

In the past 18 months, the U.S. Food and Drug Administration approved macitentan, riociguat, and treprostinil as oral agents for the treatment of pulmonary arterial hypertension (PAH); riociguat also became the first agent approved for the treatment of chronic thromboembolic pulmonary hypertension (CTEPH). These new agents are welcome additional therapeutic options for PAH and CTEPH. However, their use can be complicated by potential drug interactions, adverse effects, dosing complexity, and cost. Macitentan, the newest endothelin receptor antagonist, showed significant benefits in a long-term event-driven trial of morbidity and mortality. Dosed once daily and with minimal liver toxicity, it has potential drug interactions with potent CYP 3A4 inhibitors and inducers, and can decrease hemoglobin levels. Riociguat is approved for PAH and clinically inoperable CTEPH to improve exercise capacity and functional status. Riociguat requires dose titration beginning with 1 mg up to 2.5 mg three times a day, as tolerated, and should be used with caution in patients with underlying risk factors for systemic hypotension. Oral treprostinil, approved to improve exercise capacity in PAH, is associated with gastrointestinal side effects and headaches that are often dose limiting. Doses can begin with 0.125 mg or 0.25 mg twice a day with gradual increases on up to a weekly basis, as tolerated. Thrice daily dosing and administration with a meal can improve tolerance. These newer agents represent advances, but their specific roles in relation to pre-existing therapies are undergoing further evaluation. Therefore, close collaboration with clinicians at centers with therapeutic expertise is highly recommended to optimize patient outcomes.

Metabolic control during exercise with and without medium-chain triglycerides (MCT) in children with long-chain 3-hydroxy acyl-CoA dehydrogenase (LCHAD) or trifunctional protein (TFP) deficiency

PubMed Central

Gillingham, Melanie B.; Scott, Bradley; Elliott, Diane; Harding, Cary O.

2009-01-01

Exercise induced rhabdomyolysis is a complication of long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD) and mitochondrial trifunctional protein (TFP) deficiency that frequently leads to exercise avoidance. Dietary therapy for most subjects includes medium-chain triglyceride (MCT) supplementation but analysis of diet records indicates that the majority of patients consume oral MCT only with breakfast and at bedtime. We hypothesized that MCT immediately prior to exercise would provide an alternative fuel source during that bout of exercise and improve exercise tolerance in children with LCHAD deficiency. Nine subjects completed two 45 min moderate intensity (60–70% predicted maximum heart rate (HR)) treadmill exercise tests. Subjects were given 4 oz of orange juice alone or orange juice and 0.5 g MCT per kg lean body mass, 20 min prior to exercise in a randomized cross-over design. ECG and respiratory gas exchange including respiratory quotient (RQ) were monitored. Blood levels of acylcarnitines, creatine kinase, lactate, and β-hydroxybutyrate were measured prior to and immediately after exercise, and again following 20min rest. Creatine kinase and lactate levels did not change with exercise. There was no significant difference in RQ between the two exercise tests but there was a decrease in steady-state HR following MCT supplementation. Cumulative long-chain 3-hydroxyacylcarnitines were 30% lower and β-hydroxybutyrate was three-fold higher after the MCT-pretreated exercise test compared to the test with orange juice alone. Coordinating MCT supplementation with periods of increased activity may improve the metabolic control of children with LCHAD and TFP deficiency following exercise. PMID:16876451

Effects of tiotropium on lung hyperinflation, dyspnoea and exercise tolerance in COPD.

PubMed

O'Donnell, D E; Flüge, T; Gerken, F; Hamilton, A; Webb, K; Aguilaniu, B; Make, B; Magnussen, H

2004-06-01

The aim of this study was to test the hypothesis that use of tiotropium, a new long-acting anticholinergic bronchodilator, would be associated with sustained reduction in lung hyperinflation and, thereby, would improve exertional dyspnoea and exercise performance in patients with chronic obstructive pulmonary disease. A randomised, double-blind, placebo-controlled, parallel-group study was conducted in 187 patients (forced expiratory volume in one second 44 +/- 13% pred): 96 patients received 18 microg tiotropium and 91 patients received placebo once daily for 42 days. Spirometry, plethysmographic lung volumes, cycle exercise endurance and exertional dyspnoea intensity at 75% of each patient's maximal work capacity were compared. On day 42, the use of tiotropium was associated with the following effects at pre-dose and post-dose measurements as compared to placebo: vital capacity and inspiratory capacity (IC) increased, with inverse decreases in residual volume and functional residual capacity. Tiotropium increased post-dose exercise endurance time by 105 +/- 40 s (21%) as compared to placebo on day 42. At a standardised time near end-exercise (isotime), IC, tidal volume and minute ventilation all increased, whilst dyspnoea decreased by 0.9 +/- 0.3 Borg scale units. In conclusion, the use of tiotropium was associated with sustained reductions of lung hyperinflation at rest and during exercise. Resultant increases in inspiratory capacity permitted greater expansion of tidal volume and contributed to improvements in both exertional dyspnoea and exercise endurance.

Exercise and diet enhance fat oxidation and reduce insulin resistance in older obese adults

PubMed Central

Solomon, Thomas P.J.; Sistrun, Sakita N.; Krishnan, Raj K.; Del Aguila, Luis F.; Marchetti, Christine M.; O'Carroll, Susan M.; O'Leary, Valerie B.; Kirwan, John P.

2013-01-01

Older, obese, and sedentary individuals are at high risk of developing diabetes and cardiovascular disease. Exercise training improves metabolic anomalies associated with such diseases, but the effects of caloric restriction in addition to exercise in such a high risk group are not known. Changes in body composition and metabolism during a lifestyle intervention were investigated in twenty three older, obese men and women (aged 66 ± 1 years, BMI 33.2 ± 1.4 kg.m−2) with impaired glucose tolerance. All volunteers undertook twelve weeks of aerobic exercise training (5 days per week for 60 min @ 75% VO2max) with either normal caloric intake (eucaloric group, 1901 ± 277 kcal.day−1, n = 12) or a reduced-calorie diet (hypocaloric group, 1307 ± 70 kcal.day−1, n = 11), as dictated by nutritional counseling. Body composition (decreased fat mass; maintained fat-free mass), aerobic fitness (VO2max), leptinemia, insulin sensitivity, and intramyocellular lipid accumulation (IMCL) in skeletal muscle improved in both groups (P < 0.05). Improvements in body composition, leptin and basal fat oxidation were greater in the hypocaloric group. Following the intervention there was a correlation between the increase in basal fat oxidation and the decrease in IMCL (r = −0.53, P = 0.04). In addition, basal fat oxidation was associated with circulating leptin after (r = 0.65, P = 0.0007), but not before the intervention (r = 0.05, P = 0.84). In conclusion, these data show that exercise training improves resting substrate oxidation and creates a metabolic milieu that appears to promote lipid utilization in skeletal muscle, thus facilitating a reversal of insulin resistance. We also demonstrate that leptin sensitivity is improved, but that such a trend may rely on reducing caloric intake in addition to exercise training. PMID:18323464

Impact of Overt and Subclinical Hypothyroidism on Exercise Tolerance: A Systematic Review

ERIC Educational Resources Information Center

Lankhaar, Jeannette A. C.; de Vries, Wouter R.; Jansen, Jaap A. C. G.; Zelissen, Pierre M. J.; Backx, Frank J. G.

2014-01-01

Purpose: This systematic review describes the state of the art of the impact of hypothyroidism on exercise tolerance and physical performance capacity in untreated and treated patients with hypothyroidism. Method: A systematic computer-aided search was conducted using biomedical databases. Relevant studies in English, German, and Dutch, published…

Long-term effects of an exercise and Mediterranean diet intervention in the vascular function of an older, healthy population.

PubMed

Klonizakis, Markos; Alkhatib, Ahmad; Middleton, Geoff

2014-09-01

Preserving endothelial function and microvascular integrity is suggested to reduce cardiovascular disease risk. It was recently shown that the age-dependent decline in endothelial and microvascular integrity may be reversed when combining exercise with Mediterranean diet (MD) in an 8-week intervention. The present study investigates whether the risk-reduction improvement in microcirculatory and cardiorespiratory functions are sustained in this age-group after a 1-year follow-up. Twenty sedentary healthy participants (age, 55±4years) from the original study underwent cardiopulmonary exercise tolerance test and were assessed for their upper- and lower-limb vascular endothelial cutaneous vascular conductance (CVC) using laser Doppler fluximetry (LDF) with endothelium-dependent [ACh (acetylcholine chloride)] and endothelium-independent [SNP (sodium nitroprusside)] vasodilation, 1year after completing the intervention. Both MD and exercise groups appeared to have an improved microvascular responses, in comparison to baseline as far as ACh is concerned. Exploring the interactions between the time point and the original group, however, revealed a stronger improvement in the MD group in comparison to the exercise group, for ACh (p=0.04, d=0.41). In the upper body, the time point and group interaction for ACh, indicated a better improvement for MD, without however statistical significance (p=0.07, d=0.24). Additionally, cardiorespiratory improvement in ventilatory threshold was maintained, 1year after (12.2±3.0 vs. 13.2±3.2ml∙kg(-1)∙min(-1), p<0.05). The original improvements from an 8-week exercise and MD intervention were still evident, particularly in the microcirculatory and cardiorespiratory assessments, 1year after the initial study. This suggests that a brief intervention combining MD with exercise in this high-risk group promises long-term health benefits. Copyright © 2014 Elsevier Inc. All rights reserved.

The physiological basis of rehabilitation in chronic heart and lung disease.

PubMed

Vogiatzis, Ioannis; Zakynthinos, Spyros

2013-07-01

Cardiopulmonary rehabilitation is recognized as a core component of management of individuals with congestive heart failure (CHF) or chronic obstructive pulmonary disease (COPD) that is designed to improve their physical and psychosocial condition without impacting on the primary organ impairment. This has lead the scientific community increasingly to believe that the main effects of cardiopulmonary rehabilitative exercise training are focused on skeletal muscles that are regarded as dysfunctional in both CHF and COPD. Accordingly, following completion of a cardiopulmonary rehabilitative exercise training program there are important peripheral muscular adaptations in both disease entities, namely increased capillary density, blood flow, mitochondrial volume density, fiber size, distribution of slow twitch fibers, and decreased lactic acidosis and vascular resistance. Decreased lactic acidosis at a given level of submaximal exercise not only offsets the occurrence of peripheral muscle fatigue, leading to muscle task failure and muscle discomfort, but also concurrently mitigates the additional burden on the respiratory muscles caused by the increased respiratory drive, thereby reducing dyspnea sensations. Furthermore in patients with COPD, exercise training reduces the degree of dynamic lung hyperinflation leading to improved arterial oxygen content and central hemodynamic responses, thus increasing systemic muscle oxygen availability. In patients with CHF, exercise training has beneficial direct and reflex sympathoinhibitory effects and favorable effects on normalization of neurohumoral excitation. These physiological benefits apply to all COPD and CHF patients independently of the degree of disease severity and are associated with improved exercise tolerance, functional capacity, and quality of life.

[Effectiveness of an educational program for respiratory rehabilitation of Chronic Obstructive Pulmonary Disease patients in Primary Care in improving the quality of life, symptoms, and clinical risk].

PubMed

Blánquez Moreno, Cristina; Colungo Francia, Cristina; Alvira Balada, M Carme; Kostov, Belchin; González-de Paz, Luis; Sisó-Almirall, Antoni

2017-10-04

To determine the impact of an educational program to improve the management of chronic obstructive pulmonary disease (COPD) that contributes to an increase of the quality of life, exercise capacity, level of dyspnoea, and clinical risk. Intervention study without controls. Primary Healthcare Centre. 193 patients with COPD were invited, 73 accepted and 55 participated in the educational program. Respiratory rehabilitation educational program with basic concepts of pulmonary and respiratory pathophysiology, respiratory physiotherapy exercises, practical workshop on the use of the most frequent inhalation devices, understanding of chronic disease and self-care measures in case of exacerbation. The quality of life (the COPD assessment test), exercise tolerance (the Six-Minute Walk Test), rating of perceived exertion (Borg Dyspnoea Score) and clinical risk (BODE index) were assessed by means of validated questionnaires in Spanish. A total of 43 (78.2%) participants completed the program. An improvement in the quality of life by a mean of 3.3 points was observed (95%CI; 1.76-4.84). Just over half (53.5%) of the participants obtained a clinically relevant improvement. Participants also improved their physical exercise capacity at post-intervention by increasing the distance that they walked in 6min by a mean of 20.76m (95%CI; 2.57-38.95). Improvements in the level of dyspnoea and clinical risk were also observed. The educational program shows a statistically significant and clinically relevant improvement in the quality of life, fatigue, symptomatology, exercise capacity, level of dyspnoea, and clinical risk. The program is adaptable to the health care routine of healthcare centres. Copyright © 2017 Elsevier España, S.L.U. All rights reserved.

A Systematic Review of Exercise Systematic Reviews in the Cancer Literature (2005-2017).

PubMed

Stout, Nicole L; Baima, Jennifer; Swisher, Anne K; Winters-Stone, Kerri M; Welsh, Judith

2017-09-01

Evidence supports the benefits of exercise for patients with cancer; however, specific guidance for clinical decision making regarding exercise timing, frequency, duration, and intensity is lacking. Efforts are needed to optimize clinical recommendations for exercise in the cancer population. To aggregate information regarding the benefit of exercise through a systematic review of existing systematic reviews in the cancer exercise literature. PubMed, CINAHL Plus, Scopus, Web of Science, and EMBASE. Systematic reviews and meta-analyses of the impact of movement-based exercise on the adult cancer population. Two author teams reviewed 302 abstracts for inclusion with 93 selected for full-text review. A total of 53 studies were analyzed. A Measurement Tool to Assess Systematic Reviews (AMSTAR) was used as a quality measure of the reviews. Information was extracted using the PICO format (ie, participants, intervention, comparison, outcomes). Descriptive findings are reported. Mean AMSTAR score = 7.66/11 (±2.04) suggests moderate quality of the systematic reviews. Exercise is beneficial before, during, and after cancer treatment, across all cancer types, and for a variety of cancer-related impairments. Moderate-to-vigorous exercise is the best level of exercise intensity to improve physical function and mitigate cancer-related impairments. Therapeutic exercises are beneficial to manage treatment side effects, may enhance tolerance to cancer treatments, and improve functional outcomes. Supervised exercise yielded superior benefits versus unsupervised. Serious adverse events were not common. Movement-based exercise intervention outcomes are reported. No analysis of pooled effects was calculated across reviews due to significant heterogeneity within the systematic reviews. Findings do not consider exercise in advanced cancers or pediatric populations. Exercise promotes significant improvements in clinical, functional, and in some populations, survival outcomes and can be recommended regardless of the type of cancer. Although generally safe, patients should be screened and appropriate precautions taken. Efforts to strengthen uniformity in clinical trial reporting, develop clinical practice guidelines, and integrate exercise and rehabilitation services into the cancer delivery system are needed. Copyright © 2017 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

Short-term evaluation of captopril in patients with chronic left sided valvular regurgitations.

PubMed

Jirasirirojanakorn, K; Mahanonda, N; Jootar, P; Chaithiraphan, S; Wansanit, K; Watanaprakarnchai, W

1998-01-01

To evaluate the clinical effects and the changes in cardiac performance of high- and low-dose captopril compared to placebo in patients with chronic symptomatic aortic regurgitation (AR), and/or mitral regurgitation (MR). We randomized patients into three groups, placebo (Group 1), incremental daily doses of 50 mg (Group 2), and 100 mg captopril (Group 3). We compared exercise capacity before and after four-week of treatment. Treatment was well tolerated with no serious side effects including blood chemistry. There were no significant effects of treatment on left ventricular dimensions nor calculated left ventricular ejection fraction (LVEF) between groups (LVEF change -0.6%, -2.6%, 2.4%, in group 1, 2 and 3 respectively; p > 0.05). No difference of exercise duration between treatment and placebo arms (change by 13%, 12.8%, 16.4%, respectively; p > 0.05). However, there were trends in the number of the patients who improved in left ventricular performance (absolute LVEF change > 5% unit = 15%, 16%, and 42% respectively; p > 0.05) and exercise performance (exercise time improvement > 75 sec = 50%, 47%, and 68% respectively; p > 0.05) in high dose captopril treatment group. There was no significant improvement of left ventricular performance and exercise capacity after four-weeks' treatment of low and high dose captopril. Further study with a larger sample size, and longer follow-up period may be required.

Mind-Body Skills Training to Improve Distress Tolerance in Medical Students: A Pilot Study.

PubMed

Kraemer, Kristen M; Luberto, Christina M; O'Bryan, Emily M; Mysinger, Erica; Cotton, Sian

2016-01-01

Medical students face rigorous and stressful work environments, resulting in high rates of psychological distress. However, there has been a dearth of empirical work aimed at modifying risk factors for psychopathology among this at-risk group. Distress tolerance, defined as the ability to withstand emotional distress, is one factor that may be important in promoting psychological well-being in medical students. Thus, the aim of the current mixed-methods study was (a) to describe changes in facets of distress tolerance (i.e., emotional tolerance, absorption, appraisal, regulation) for medical students who completed a mind-body skills training group, and a no-intervention control group of students; (b) to examine the relationship between changes in psychological variables and changes in distress tolerance; and (c) to report students' perceptions of the mind-body group, with an emphasis on how the group may have affected personal and professional functioning due to improvements in distress tolerance. The mind-body program was an 11-week, 2-hour skills training group that focused on introducing, practicing, and processing mind-body skills such as biofeedback, guided imagery, relaxation, several forms of meditation (e.g., mindfulness), breathing exercises, and autogenic training. Participants were 52 first- and second-year medical students (62.7% female, Mage = 23.45, SD = 1.51) who participated in a mind-body group or a no-intervention control group and completed self-report measures before and after the 11-week period. Students in the mind-body group showed a modest improvement in all distress tolerance subscales over time (ΔM = .42-.53, p = .01-.03, d = .44-.53), whereas the control group showed less consistent changes across most subscales (ΔM = .11-.42, p = .10-.65, d = .01-.42). Students in the mind-body group qualitatively reported an improved ability to tolerate affective distress. Overall, improvements in psychological symptoms were associated with improvements in distress tolerance in the mind-body group but not in the control group. These preliminary findings provide support for the notion that improving distress tolerance through mind-body skills training might serve to protect medical students from becoming functionally impaired by psychological distress. Thus, implementing mind-body skills training into medical school education may help to improve the psychological well-being of medical students. Future studies utilizing more methodologically rigorous designs are warranted.

The effects of physical exercise on patients with Crohn's disease.

PubMed

Loudon, C P; Corroll, V; Butcher, J; Rawsthorne, P; Bernstein, C N

1999-03-01

Despite the suggested benefits of exercise training in the prevention and management of chronic diseases, few data exist regarding the safety of exercise in Crohn's disease and whether or not exercise may have beneficial effects on patients' health. We performed a pilot study to evaluate the effects of regular light-intensity exercise on sedentary patients with Crohn's disease. Sedentary patients with inactive or mildly active Crohn's disease were eligible for the study. A thrice-weekly, 12-wk walking program was supervised, although if subjects could not attend the group walking sessions they were allowed to walk on their own. Logbooks of performance were maintained, and individual exercise heart rate goals were established. Measures performed at baseline and at study completion included the Inflammatory Bowel Disease Stress Index, the Inflammatory Bowel Disease Quality of Life Score, the Harvey and Bradshaw Simple Index, the Canadian Aerobic Fitness Test, VO2 Max, and body mass index (BMI). Twelve subjects completed the 12-wk exercise program. Subjects walked an average of 2.9 sessions/wk, at an average of 32.6 min/session, and for an average distance of 3.5 km/session. Statistically significant improvements at study end were seen by all measures, with a trend toward reduction in BMI. No patient's disease flared during the study. Sedentary patients with Crohn's disease can tolerate low-intensity exercise of moderate duration without an exacerbation of symptoms. Twelve weeks of walking was adequate to elicit psychological and physical improvements and did not adversely affect disease activity.

Exercise Therapy in Juvenile Idiopathic Arthritis: A Systematic Review and Meta-Analysis.

PubMed

Kuntze, Gregor; Nesbitt, Colleen; Whittaker, Jackie L; Nettel-Aguirre, Alberto; Toomey, Clodagh; Esau, Shane; Doyle-Baker, Patricia K; Shank, Jena; Brooks, Julia; Benseler, Susanne; Emery, Carolyn A

2018-01-01

To conduct a systematic review to evaluate the efficacy of exercise interventions in improving outcomes across domains of functioning and disability in children and adolescents with juvenile idiopathic arthritis (JIA). Seven electronic databases were systematically searched up to November 16, 2016. Original data, analytic prospective design, physical therapy-led exercise intervention evaluation, children and adolescents with JIA, and assessment of functional, structural, activity, participation, or quality of life outcomes. Two authors screened search results, and discrepancies were resolved by consensus. Of 5037 potentially relevant studies, 9 randomized controlled trials and 1 cohort study were included and scored. Study quality (Downs and Black quality assessment tool) and level of evidence (Oxford Centre of Evidence-Based Medicine model) were assessed and meta-analysis conducted where appropriate. Alternatively, a descriptive summary approach was chosen. All randomized controlled trials were moderate-quality intervention studies (level 2b evidence; median Downs and Black score, 20 out of 32; range, 15-27). Interventions included aquatic, strengthening, proprioceptive, aerobic, and Pilates exercises. Pediatric activity capacity (Child Health Assessment Questionnaire) improved with exercise (mean difference, .45; 95% confidence interval, .05-.76). Furthermore, descriptive summaries indicated improved activity capacity, body function and structure (pain and muscle strength), and quality of life outcomes. Exercise therapy appears to be well tolerated and beneficial across clinically relevant outcomes in patients with JIA. The paucity of high-quality evidence and study heterogeneity limited the ability to provide conclusive, generalizing evidence for the efficacy of exercise therapy and to provide specific recommendations for clinical practice at this time. Future research evaluating exercise program implementation using validated outcomes and detailed adherence and safety assessment is needed to optimize clinical decision pathways in patients with JIA. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

The Acute and Residual Effect of a Single Exercise Session on Meal Glucose Tolerance in Sedentary Young Adults

PubMed Central

Short, Kevin R.; Pratt, Lauren V.; Teague, April M.

2012-01-01

The study goals were to (1) establish the variability in postprandial glucose control in healthy young people consuming a mixed meal and, then (2) determine the acute and residual impact of a single exercise bout on postprandial glucose control. In study 1, 18 people completed two similar mixed meal trials and an intravenous glucose tolerance test (IVGTT). There were strong test-retest correlations for the post-meal area under the curve (AUC) for glucose, insulin, and Cpeptide (r = 0.73–0.83) and the Matsuda insulin sensitivity index (ISI, r = 0.76), and between meal and IVGTT-derived ISI (r = 0.83). In study 2, 11 untrained young adults completed 3 trials. One trial (No Ex) was completed after refraining from vigorous activity for ≥3 days. On the other 2 trials, a 45-min aerobic exercise bout was performed either 17-hours (Prior Day Ex) or 1-hour (Same Day Ex) before consuming the test meal. Compared to No Ex and Prior Day Ex, which did not differ from one another, there were lower AUCs on the Same Day Ex trial for glucose (6%), insulin (20%) and C-peptide (14%). Thus, a single moderate intensity exercise session can acutely improve glycemic control but the effect is modest and short-lived. PMID:22666560

Design and rationale of the HITTS randomized controlled trial: Effect of High-intensity Interval Training in de novo Heart Transplant Recipients in Scandinavia.

PubMed

Nytrøen, Kari; Yardley, Marianne; Rolid, Katrine; Bjørkelund, Elisabeth; Karason, Kristjan; Wigh, Julia Philip; Dall, Christian Have; Arora, Satish; Aakhus, Svend; Lunde, Ketil; Solberg, Ole Geir; Gustafsson, Finn; Prescott, Eva Irene Bossano; Gullestad, Lars

2016-02-01

There is no consensus on how, when, and at what intensity exercise should be performed and organized after heart transplantation (HTx). Most rehabilitation programs are conducted in HTx centers, which might be impractical and costly. We have recently shown that high-intensity interval training (HIT) is safe, well tolerated, and efficacious in maintenance HTx recipients, but there are no studies among de novo patients, and whether HIT is feasible and superior to moderate training in HTx recipients is unclear. A total of 120 clinically stable HTx recipients older than 18 years will be recruited from 3 Scandinavian HTx centers. Participants are randomized to HIT or moderate training, shortly after surgery. All exercises are supervised in the patients' local communities. Testing at baseline and follow-up includes the following: VO2peak (primary end point), muscle strength, body composition, quality of life, myocardial performance, endothelial function, biomarkers, and progression of cardiac allograft vasculopathy. A subgroup (n = 90) will also be tested at 3-year follow-up to assess long-term effects of exercise. So far, the HIT intervention is well tolerated, without any serious adverse events. We aim to test whether decentralized HIT is feasible, safe, and superior to moderate training, and whether it will lead to significant improvement in exercise capacity and less long-term complications. Copyright © 2015 Elsevier Inc. All rights reserved.

A randomised double blind placebo controlled clinical trial of a standardised extract of fresh Crataegus berries (Crataegisan) in the treatment of patients with congestive heart failure NYHA II.

PubMed

Degenring, F H; Suter, A; Weber, M; Saller, R

2003-01-01

A placebo controlled, randomised, parallel group, multicentre trial conducted in accordance with the guidelines of Good Clinical Practice (GCP) shows the efficacy and safety of a standardised extract of fresh berries of Crataegus oxyacantha L. and monogyna Jacq. (Crataegisan) in patients with cardiac failure NYHA class II. A total of 143 patients (72 men, 71 women, mean age of 64.8 (8.0 years) were recruited and treated with 3 times 30 drops of the extract (n = 69) or placebo (n = 74) for 8 weeks. The primary variable for the evaluation of efficacy was the change in exercise tolerance determined with bicycle exercise testing, secondary variables included the blood pressure-heart rate product (BHP). Subjective cardiac symptoms at rest and at higher levels of exertion were assessed by the patient on a categorical rating scale. An overall assessment of efficacy at the final visit was provided by the patient and the investigator. In the ITT population there was a significant increase in exercise tolerance in both groups between visit 1 and visit 3. The difference between the treatment groups was 8.3 watts in favour of the standardised extract of fresh Crataegus berries (p = 0.045). The result is confirmed in the PP population (p = 0.047). Changes in BHP at 50 watts and at comparable maximum load were in favour of Crataegus extract but the results are not statistically significant. The subjective assessment of cardiac symptoms at rest and at higher levels of exertion did not change significantly and the patient and investigator overall assessment of efficacy were similar for the two groups. The medication was well tolerated and had a high level of patient acceptability. The significant improvement, due to the fact that dyspnoea and fatigue do not occur until a significantly higher wattage has been reached in the bicycle exercise testing allows the conclusion that the recruited NYHA II patients may expect an improvement in their heart failure condition under long term therapy with the standardised extract of fresh Crataegus berries.

The glucose-dependent insulinotropic polypeptide and glucose-stimulated insulin response to exercise training and diet in obesity

PubMed Central

Kelly, Karen R.; Brooks, Latina M.; Solomon, Thomas P. J.; Kashyap, Sangeeta R.; O'Leary, Valerie B.; Kirwan, John P.

2009-01-01

Aging and obesity are characterized by decreased β-cell sensitivity and defects in the potentiation of nutrient-stimulated insulin secretion by GIP. Exercise and diet are known to improve glucose metabolism and the pancreatic insulin response to glucose, and this effect may be mediated through the incretin effect of GIP. The purpose of this study was to assess the effects of a 12-wk exercise training intervention (5 days/wk, 60 min/day, 75% V̇o2 max) combined with a eucaloric (EX, n = 10) or hypocaloric (EX-HYPO, pre: 1,945 ± 190, post: 1,269 ± 70, kcal/day; n = 9) diet on the GIP response to glucose in older (66.8 ± 1.5 yr), obese (34.4 ± 1.7 kg/m2) adults with impaired glucose tolerance. In addition to GIP, plasma PYY3–36, insulin, and glucose responses were measured during a 3-h, 75-g oral glucose tolerance test. Both interventions led to a significant improvement in V̇o2 max (P < 0.05). Weight loss (kg) was significant in both groups but was greater after EX-HYPO (−8.3 ± 1.1 vs. −2.8 ± 0.5, P = 0.002). The glucose-stimulated insulin response was reduced after EX-HYPO (P = 0.02), as was the glucose-stimulated GIP response (P < 0.05). Furthermore, after the intervention, changes in insulin (ΔI0–30/ΔG0–30) and GIP (Δ0–30) secretion were correlated (r = 0.69, P = 0.05). The PYY3–36 (Δ0–30) response to glucose was increased after both interventions (P < 0.05). We conclude that 1) a combination of caloric restriction and exercise reduces the GIP response to ingested glucose, 2) GIP may mediate the attenuated glucose-stimulated insulin response after exercise/diet interventions, and 3) the increased PYY3–36 response represents an improved capacity to regulate satiety and potentially body weight in older, obese, insulin-resistant adults. PMID:19351807

Effects of exercise training and diet on lipid kinetics during free fatty acid-induced insulin resistance in older obese humans with impaired glucose tolerance

PubMed Central

Solomon, Thomas P. J.; Haus, Jacob M.; Marchetti, Christine M.; Stanley, William C.; Kirwan, John P.

2009-01-01

Elevated free fatty acids (FFA) are implicated with insulin resistance at the cellular level. However, the contribution of whole body lipid kinetics to FFA-induced insulin resistance is not well understood, and the effect of exercise and diet on this metabolic defect is not known. We investigated the effect of 12 wk of exercise training with and without caloric restriction on FFA turnover and oxidation (FFAox) during acute FFA-induced insulin resistance. Sixteen obese subjects with impaired glucose tolerance were randomized to either a hypocaloric (n = 8; −598 ± 125 kcal/day, 66 ± 1 yr, 32.8 ± 1.8 kg/m2) or a eucaloric (n = 8; 67 ± 2 yr, 35.3 ± 2.1 kg/m2) diet and aerobic exercise (1 h/day at 65% of maximal oxygen uptake) regimen. Lipid kinetics ([1-14C]palmitate) were assessed throughout a 7-h, 40 mU·m−2·min−1 hyperinsulinemic euglycemic clamp, during which insulin resistance was induced in the last 5 h by a sustained elevation in plasma FFA (intralipid/heparin infusion). Despite greater weight loss in the hypocaloric group (−7.7 ± 0.5 vs. −3.3 ± 0.7%, P < 0.001), FFA-induced peripheral insulin resistance was improved equally in both groups. However, circulating FFA concentrations (2,123 ± 261 vs. 1,764 ± 194 μmol/l, P < 0.05) and FFA turnover (3.20 ± 0.58 vs. 2.19 ± 0.58 μmol·kg FFM−1·min−1, P < 0.01) during hyperlipemia were suppressed only in the hypocaloric group. In contrast, whole body FFAox was improved in both groups at rest and during hyperlipemia. These changes were driven by increases in intracellular lipid-derived FFAox (12.3 ± 7.7 and 14.7 ± 7.8%, P < 0.05). We conclude that the exercise-induced improvement in FFA-induced insulin resistance is independent of the magnitude of weight loss and FFA turnover, yet it is linked to increased intracellular FFA utilization. PMID:19531640

Aerobic Exercise Training Improves Orthostatic Tolerance in Aging Humans.

PubMed

Xu, Diqun; Wang, Hong; Chen, Shande; Ross, Sarah; Liu, Howe; Olivencia-Yurvati, Albert; Raven, Peter B; Shi, Xiangrong

2017-04-01

This study was designed to test the hypothesis that aerobic exercise training of the elderly will increase aerobic fitness without compromising orthostatic tolerance (OT). Eight healthy sedentary volunteers (67.0 ± 1.7 yr old, four women) participated in 1 yr of endurance exercise training (stationary bicycle and/or treadmill) program at the individuals' 65%-75% of HRpeak. Peak O2 uptake (V˙O2peak) and HRpeak were determined by a maximal exercise stress test using a bicycle ergometer. Carotid baroreceptor reflex (CBR) control of HR and mean arterial pressure (MAP) were assessed by a neck pressure-neck suction protocol. Each subject's maximal gain (Gmax), or sensitivity, of the CBR function curves were derived from fitting their reflex HR and MAP responses to the corresponding neck pressure-neck suction stimuli using a logistic function curve. The subjects' OT was assessed using lower-body negative pressure (LBNP) graded to -50 mm Hg; the sum of the product of LBNP intensity and time (mm Hg·min) was calculated as the cumulative stress index. Training increased V˙O2peak (before vs after: 22.8 ± 0.92 vs 27.9 ± 1.33 mL·min·kg, P < 0.01) and HRpeak (154 ± 4 vs 159 ± 3 bpm, P < 0.02) and decreased resting HR (65 ± 5 vs 59 ± 5 bpm, P < 0.02) and MAP (99 ± 2 vs 87 ± 2 mm Hg, P < 0.05). CBR stimulus-response curves identified a leftward shift with an increase in CBR-HR Gmax (from -0.13 ± 0.02 to -0.27 ± 0.04 bpm·mm Hg, P = 0.01). Cumulative stress index was increased from 767 ± 68 mm Hg·min pretraining to 946 ± 44 mm Hg·min posttraining (P < 0.05). Aerobic exercise training improved the aerobic fitness and OT in elderly subjects. An improved OT is likely associated with an enhanced CBR function that has been reset to better maintain cerebral perfusion and cerebral tissue oxygenation during LBNP.

Heat Acclimation and Water-Immersion Deconditioning: Responses to Exercise

NASA Technical Reports Server (NTRS)

Shvartz, E.; Bhattacharya, A.; Sperinde, S. J.; Brock, P. J.; Sciaraffa, D.; Haines, R. F.; Greenleaf, J. E.

1977-01-01

Simulated subgravity conditions, such as bed rest and water immersion, cause a decrease in a acceleration tolerance (3, 4), tilt tolerance (3, 9, 10), work capacity (5, 7), and plasma volume (1, 8-10). Moderate exercise training performed during bed rest (4) and prior to water immersion (5) provides some protection against the adverse effects of deconditioning, but the relationship between exercise and changes due to deconditioning remains unclear. Heat acclimation increases plasma and interstitial volumes, total body water, stroke volume (11), and tilt tolerance (6) and may, therefore, be a more efficient method of ameliorating deconditioning than physical training alone. The present study was undertaken to determine the effects of heat acclimation and moderate physical training, performed in cool conditions, on water-immersion deconditioning.

Active and passive heat stress similarly compromise tolerance to a simulated hemorrhagic challenge.

PubMed

Pearson, J; Lucas, R A I; Schlader, Z J; Zhao, J; Gagnon, D; Crandall, C G

2014-10-01

Passive heat stress increases core and skin temperatures and reduces tolerance to simulated hemorrhage (lower body negative pressure; LBNP). We tested whether exercise-induced heat stress reduces LBNP tolerance to a greater extent relative to passive heat stress, when skin and core temperatures are similar. Eight participants (6 males, 32 ± 7 yr, 176 ± 8 cm, 77.0 ± 9.8 kg) underwent LBNP to presyncope on three separate and randomized occasions: 1) passive heat stress, 2) exercise in a hot environment (40°C) where skin temperature was moderate (36°C, active 36), and 3) exercise in a hot environment (40°C) where skin temperature was matched relative to that achieved during passive heat stress (∼38°C, active 38). LBNP tolerance was quantified using the cumulative stress index (CSI). Before LBNP, increases in core temperature from baseline were not different between trials (1.18 ± 0.20°C; P > 0.05). Also before LBNP, mean skin temperature was similar between passive heat stress (38.2 ± 0.5°C) and active 38 (38.2 ± 0.8°C; P = 0.90) trials, whereas it was reduced in the active 36 trial (36.6 ± 0.5°C; P ≤ 0.05 compared with passive heat stress and active 38). LBNP tolerance was not different between passive heat stress and active 38 trials (383 ± 223 and 322 ± 178 CSI, respectively; P = 0.12), but both were similarly reduced relative to active 36 (516 ± 147 CSI, both P ≤ 0.05). LBNP tolerance is not different between heat stresses induced either passively or by exercise in a hot environment when skin temperatures are similarly elevated. However, LBNP tolerance is influenced by the magnitude of the elevation in skin temperature following exercise induced heat stress. Copyright © 2014 the American Physiological Society.

Estimating exercise capacity from walking tests in elderly individuals with stable coronary artery disease.

PubMed

Mandic, Sandra; Walker, Robert; Stevens, Emily; Nye, Edwin R; Body, Dianne; Barclay, Leanne; Williams, Michael J A

2013-01-01

Compared with symptom-limited cardiopulmonary exercise test (CPET), timed walking tests are cheaper, well-tolerated and simpler alternative for assessing exercise capacity in coronary artery disease (CAD) patients. We developed multivariate models for predicting peak oxygen consumption (VO2peak) from 6-minute walk test (6MWT) distance and peak shuttle walk speed for elderly stable CAD patients. Fifty-eight CAD patients (72 SD 6 years, 66% men) completed: (1) CPET with expired gas analysis on a cycle ergometer, (2) incremental 10-meter shuttle walk test, (3) two 6MWTs, (4) anthropometric assessment and (5) 30-second chair stands. Linear regression models were developed for estimating VO2peak from 6MWT distance and peak shuttle walk speed as well as demographic, anthropometric and functional variables. Measured VO2peak was significantly related to 6MWT distance (r = 0.719, p < 0.001) and peak shuttle walk speed (r = 0.717, p < 0.001). The addition of demographic (age, gender), anthropometric (height, weight, body mass index, body composition) and functional characteristics (30-second chair stands) increased the accuracy of predicting VO2peak from both 6MWT distance and peak shuttle walk speed (from 51% to 73% of VO2peak variance explained). Addition of demographic, anthropometric and functional characteristics improves the accuracy of VO2peak estimate based on walking tests in elderly individuals with stable CAD. Implications for Rehabilitation Timed walking tests are cheaper, well-tolerated and simpler alternative for assessing exercise capacity in cardiac patients. Walking tests could be used to assess individual's functional capacity and response to therapeutic interventions when symptom-limited cardiopulmonary exercise testing is not practical or not necessary for clinical reasons. Addition of demographic, anthropometric and functional characteristics improves the accuracy of peak oxygen consumption estimate based on 6-minute walk test distance and peak shuttle walk speed in elderly patients with coronary artery disease.

Beetroot-based gel supplementation improves handgrip strength, forearm muscle O2 saturation but not exercise tolerance and blood volume in jiu-jitsu athletes.

PubMed

de Oliveira, Gustavo Vieira; Nascimento, Luiz; Volino-Souza, Mônica; Mesquita, Jacilene; Alvares, Thiago

2018-03-22

The ergogenic effect of beetroot on the exercise performance of trained cyclists, runners, kayakers, and swimmers has been demonstrated. However, whether or not beetroot supplementation presents a beneficial effect on the exercise performance of jiu-jitsu athletes (JJA) remains inconclusive. Therefore, present study assessed the effect of beetroot-based gel (BG) supplementation on maximal voluntary contraction (MVC), exercise time until fatigue (ETF), muscle O2 saturation (SmO2), blood volume (tHb), and plasma nitrate and lactate in response to handgrip isotonic exercise (HIE) in JJA. In a randomized, crossover, double-blind design, 12 JJA performed three sets of HIE at 40% of the MVC until fatigue after 8 days (8th dose was offered 120 min previous exercise) of BG supplementation or a nitrate-depleted gel (PLA), and forearm SmO2 and tHb were continuously monitored by using near-infrared spectroscopy. Blood samples were taken before, immediately after exercise, and 20 min after exercise recovery in PLA and BG condition. MVC was evaluated at baseline and 20 min after HIE. There was a significant reduction in ∆MVC decline after HIE in BG condition. Forearm SmO2 during exercise recovery was significantly greater only after BG supplementation. No significant difference in ETF and tHb were observed between both BG and PLA in response to HIE. Plasma nitrate increased only after BG, whereas the exercise-induced increase in plasma lactate was significantly lower in BG when compared to PLA. In conclusion, BG supplementation may be a good nutritional strategy to improve forearm SmO2 and prevent force decline in response to exercise in JJA.

Impact of Leucine Supplementation on Exercise Training Induced Anti-Cardiac Remodeling Effect in Heart Failure Mice

PubMed Central

de Moraes, Wilson Max Almeida Monteiro; Melara, Thaís Plasti; de Souza, Pamella Ramona Moraes; de Salvi Guimarães, Fabiana; Bozi, Luiz Henrique Marchesi; Brum, Patricia Chakur; Medeiros, Alessandra

2015-01-01

Leucine supplementation potentiates the effects of aerobic exercise training (AET) on skeletal muscle; however, its potential effects associated with AET on cardiac muscle have not been clarified yet. We tested whether leucine supplementation would potentiate the anti-cardiac remodeling effect of AET in a genetic model of sympathetic hyperactivity-induced heart failure in mice (α2A/α2CARKO). Mice were assigned to five groups: wild type mice treated with placebo and sedentary (WT, n = 11), α2A/α2CARKO treated with placebo and sedentary (KO, n = 9), α2A/α2CARKO treated with leucine and sedentary (KOL, n = 11), α2A/α2CARKO treated with placebo and AET (KOT, n = 12) or α2A/α2CARKO treated with leucine and AET (KOLT, n = 12). AET consisted of four weeks on a treadmill with 60 min sessions (six days/week, 60% of maximal speed) and administration by gavage of leucine (1.35 g/kg/day) or placebo (distilled water). The AET significantly improved exercise capacity, fractional shortening and re-established cardiomyocytes’ diameter and collagen fraction in KOT. Additionally, AET significantly prevented the proteasome hyperactivity, increased misfolded proteins and HSP27 expression. Isolated leucine supplementation displayed no effect on cardiac function and structure (KOL), however, when associated with AET (KOLT), it increased exercise tolerance to a higher degree than isolated AET (KOT) despite no additional effects on AET induced anti-cardiac remodeling. Our results provide evidence for the modest impact of leucine supplementation on cardiac structure and function in exercised heart failure mice. Leucine supplementation potentiated AET effects on exercise tolerance, which might be related to its recognized impact on skeletal muscle. PMID:25988767

Metformin modifies the exercise training effects on risk factors for cardiovascular disease in impaired glucose tolerant adults

PubMed Central

Malin, Steven K.; Nightingale, Joy; Choi, Sung-Eun; Chipkin, Stuart R.; Braun, Barry

2012-01-01

Impaired glucose tolerant (IGT) adults are at elevated risk for cardiovascular disease (CVD). Exercise or metformin reduce CVD risk, but the efficacy of combining treatments is unclear. To determine the effects of exercise training plus metformin, compared to each treatment alone, on CVD risk factors in IGT adults. Subjects were assigned to: placebo (P), metformin (M), exercise plus placebo (EP), or exercise plus metformin (EM) (8/group). In a double-blind design, P or 2000mg/d of M were administered for 12 weeks and half performed aerobic and resistance training 3 days/week for approximately 60 minutes/day at 70% pre-training heart rate peak. Outcomes included: adiposity, blood pressure (BP), lipids and high sensitivity C-reactive protein (hs-CRP). Z-scores were calculated to determine metabolic syndrome severity. M and EM, but not EP, decreased body weight compared to P (p <0.05). M and EP lowered systolic BP by 6% (p < 0.05), diastolic BP by 6% (p < 0.05), and hs-CRP by 20% (M: trend p = 0.06; EP: p < 0.05) compared to P. Treatments raised HDL-cholesterol (p < 0.05; EM: trend p = 0.06) compared to P and lowered triacyglycerol (p < 0.05) and metabolic syndrome Z-score compared to baseline (EP; trend p = 0.07 and EM or M; p < 0.05). Although exercise and/or metformin improve some CVD risk factors, only training or metformin alone lowered hs-CRP and BP. Thus, metformin may attenuate the effects of training on some CVD risk factors and metabolic syndrome severity in IGT adults. PMID:23505172

Muscle oxygen transport and utilization in heart failure: implications for exercise (in)tolerance.

PubMed

Poole, David C; Hirai, Daniel M; Copp, Steven W; Musch, Timothy I

2012-03-01

The defining characteristic of chronic heart failure (CHF) is an exercise intolerance that is inextricably linked to structural and functional aberrations in the O(2) transport pathway. CHF reduces muscle O(2) supply while simultaneously increasing O(2) demands. CHF severity varies from moderate to severe and is assessed commonly in terms of the maximum O(2) uptake, which relates closely to patient morbidity and mortality in CHF and forms the basis for Weber and colleagues' (167) classifications of heart failure, speed of the O(2) uptake kinetics following exercise onset and during recovery, and the capacity to perform submaximal exercise. As the heart fails, cardiovascular regulation shifts from controlling cardiac output as a means for supplying the oxidative energetic needs of exercising skeletal muscle and other organs to preventing catastrophic swings in blood pressure. This shift is mediated by a complex array of events that include altered reflex and humoral control of the circulation, required to prevent the skeletal muscle "sleeping giant" from outstripping the pathologically limited cardiac output and secondarily impacts lung (and respiratory muscle), vascular, and locomotory muscle function. Recently, interest has also focused on the dysregulation of inflammatory mediators including tumor necrosis factor-α and interleukin-1β as well as reactive oxygen species as mediators of systemic and muscle dysfunction. This brief review focuses on skeletal muscle to address the mechanistic bases for the reduced maximum O(2) uptake, slowed O(2) uptake kinetics, and exercise intolerance in CHF. Experimental evidence in humans and animal models of CHF unveils the microvascular cause(s) and consequences of the O(2) supply (decreased)/O(2) demand (increased) imbalance emblematic of CHF. Therapeutic strategies to improve muscle microvascular and oxidative function (e.g., exercise training and anti-inflammatory, antioxidant strategies, in particular) and hence patient exercise tolerance and quality of life are presented within their appropriate context of the O(2) transport pathway.

Exercise Training in Progressive Multiple Sclerosis: A Comparison of Recumbent Stepping and Body Weight-Supported Treadmill Training.

PubMed

Pilutti, Lara A; Paulseth, John E; Dove, Carin; Jiang, Shucui; Rathbone, Michel P; Hicks, Audrey L

2016-01-01

Background: There is evidence of the benefits of exercise training in multiple sclerosis (MS); however, few studies have been conducted in individuals with progressive MS and severe mobility impairment. A potential exercise rehabilitation approach is total-body recumbent stepper training (TBRST). We evaluated the safety and participant-reported experience of TBRST in people with progressive MS and compared the efficacy of TBRST with that of body weight-supported treadmill training (BWSTT) on outcomes of function, fatigue, and health-related quality of life (HRQOL). Methods: Twelve participants with progressive MS (Expanded Disability Status Scale scores, 6.0-8.0) were randomized to receive TBRST or BWSTT. Participants completed three weekly sessions (30 minutes) of exercise training for 12 weeks. Primary outcomes included safety assessed as adverse events and patient-reported exercise experience assessed as postexercise response and evaluation of exercise equipment. Secondary outcomes included the Multiple Sclerosis Functional Composite, the Modified Fatigue Impact Scale, and the Multiple Sclerosis Quality of Life-54 questionnaire scores. Assessments were conducted at baseline and after 12 weeks. Results: Safety was confirmed in both exercise groups. Participants reported enjoying both exercise modalities; however, TBRST was reviewed more favorably. Both interventions reduced fatigue and improved HRQOL (P ≤ .05); there were no changes in function. Conclusions: Both TBRST and BWSTT seem to be safe, well tolerated, and enjoyable for participants with progressive MS with severe disability. Both interventions may also be efficacious for reducing fatigue and improving HRQOL. TBRST should be further explored as an exercise rehabilitation tool for patients with progressive MS.

Exercise prescription for patients with type 2 diabetes and pre-diabetes: a position statement from Exercise and Sport Science Australia.

PubMed

Hordern, Matthew D; Dunstan, David W; Prins, Johannes B; Baker, Michael K; Singh, Maria A Fiatarone; Coombes, Jeff S

2012-01-01

Type 2 diabetes mellitus (T2DM) and pre-diabetic conditions such as impaired fasting glucose (IFG) and/or impaired glucose tolerance (IGT) are rapidly increasing in prevalence. There is compelling evidence that T2DM is more likely to develop in individuals who are insufficiently active. Exercise training, often in combination with other lifestyle strategies, has beneficial effects on preventing the onset of T2DM and improving glycaemic control in those with pre-diabetes. In addition, exercise training improves cardiovascular risk profile, body composition and cardiorespiratory fitness, all strongly related to better health outcomes. Based on the evidence, it is recommended that patients with T2DM or pre-diabetes accumulate a minimum of 210 min per week of moderate-intensity exercise or 125 min per week of vigorous intensity exercise with no more than two consecutive days without training. Vigorous intensity exercise is more time efficient and may also result in greater benefits in appropriate individuals with consideration of complications and contraindications. It is further recommended that two or more resistance training sessions per week (2-4 sets of 8-10 repetitions) should be included in the total 210 or 125 min of moderate or vigorous exercise, respectively. It is also recommended that, due to the high prevalence and incidence of comorbid conditions in patients with T2DM, exercise training programs should be written and delivered by individuals with appropriate qualifications and experience to recognise and accommodate comorbidities and complications. Copyright © 2011 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Consumption of açai (Euterpe oleracea Mart.) functional beverage reduces muscle stress and improves effort tolerance in elite athletes: a randomized controlled intervention study.

PubMed

Carvalho-Peixoto, Jacqueline; Moura, Mirian Ribeiro Leite; Cunha, Felipe Amorim; Lollo, Pablo Christiano B; Monteiro, Walace David; Carvalho, Lucia Maria Jaeger de; Farinatti, Paulo de Tarso Veras

2015-07-01

The study analyzed the effect of an açai (Euterpe oleracea Mart.) functional beverage (AB) on muscle and oxidative stress markers, cardiorespiratory responses, perceived exertion, and time-to-exhaustion during maximal treadmill running. The beverage was developed as an ergogenic aid for athletes and contained 27.6 mg of anthocyanins per dose. Fourteen athletes performed 3 exercise tests: a ramp-incremental maximal exercise test and 2 maximal exercise bouts performed in 2 conditions (AB and without AB (control)) at 90% maximal oxygen uptake. Blood was collected at baseline and after maximal exercise in both conditions to determine biomarkers. AB increased time to exhaustion during short-term high-intensity exercise (mean difference: 69 s, 95% confidence interval = -296 s to 159 s, t = 2.2, p = 0.045), attenuating the metabolic stress induced by exercise (p < 0.05). AB also reduced perceived exertion and enhanced cardiorespiratory responses (p < 0.05). The AB may be a useful and practical ergogenic aid to enhance performance during high-intensity training.

The intervention composed of aerobic training and non-exercise physical activity (I-CAN) study: Rationale, design and methods.

PubMed

Swift, Damon L; Dover, Sara E; Nevels, Tyara R; Solar, Chelsey A; Brophy, Patricia M; Hall, Tyler R; Houmard, Joseph A; Lutes, Lesley D

2015-11-01

Recent data has suggested that prolonged sedentary behavior is independent risk factor for cardiovascular and all-cause mortality independent of adequate amounts of moderate to vigorous physical activity. However, few studies have prospectively evaluated if exercise training and increasing non-exercise physical activity leads to greater reduction in cardiometabolic risk compared to aerobic training alone. The purpose of the Intervention Composed of Aerobic Training and Non-Exercise Physical Activity (I-CAN) study is to determine whether a physical activity program composed of both aerobic training (consistent with public health recommendations) and increasing non-exercise physical activity (3000 steps above baseline levels) leads to enhanced improvements in waist circumference, oral glucose tolerance, systemic inflammation, body composition, and fitness compared to aerobic training alone in obese adults (N=45). Commercially available accelerometers (Fitbits) will be used to monitor physical activity levels and behavioral coaching will be used to develop strategies of how to increase non-exercise physical activity levels. In this manuscript, we describe the design, rationale, and methodology associated with the I-CAN study. Copyright © 2015 Elsevier Inc. All rights reserved.

Current trends in cardiac rehabilitation

PubMed Central

Dafoe, W; Huston, P

1997-01-01

Cardiac rehabilitation can reduce mortality and morbidity for patients with many types of cardiac disease cost-effectively, yet is generally underutilized. Rehabilitation is helpful not only for patients who have had a myocardial infarction but also for those with stable angina or congestive heart failure or those who have undergone myocardial revascularization procedures, a heart transplant or heart valve surgery. The beneficial effects of rehabilitation include a reduction in the rate of death from cardiovascular disease, improved exercise tolerance, fewer cardiac symptoms, improved lipid levels, decreased cigarette smoking, improvement in psychosocial well-being and increased likelihood of return to work. Rehabilitation involves a multidisciplinary team that focuses on education, individually tailored exercise, risk-factor modification and the optimization of functional status and mental health. Current research trends in this area include the evaluation of new secondary-prevention modalities and alternative program options, such as home-based rehabilitation. PMID:9054823

The one year exercise and lifestyle intervention program KLAKS: Effects on anthropometric parameters, cardiometabolic risk factors and glycemic control in childhood obesity.

PubMed

Blüher, Susann; Petroff, David; Wagner, Antje; Warich, Katja; Gausche, Ruth; Klemm, Thorsten; Wagner, Mario; Keller, Alexandra

2014-03-01

Regular physical exercise within structured lifestyle programs may improve weight status and minimize metabolic risk factors in childhood obesity. The aim of this study was to evaluate the effect of the one-year combined physical exercise/lifestyle program KLAKS on anthropometric and metabolic parameters and glycemic control in childhood obesity. 142 overweight/obese (BMI>90th percentile) candidates (7-18years) were enrolled, 115 participants completed the program. Anthropometrics and biochemical parameters were obtained at beginning and completion. An oral glucose tolerance test (OGTT) was performed in a subgroup of participants. Course of glucose and insulin levels within OGTT was correlated with several parameters and is reported here for those who completed the program. The mean standard deviation scores (SDS) decreased significantly for BMI, waist circumference, waist-to-height ratio (WHtR) and percentage body fat (all p≤0.01). Improved metabolic risk markers included mean glucose levels within an OGTT at follow-up compared to baseline (p<0.0001) and HbA1c (p=0.05) as well as indications of improvement for gamma-glutamyl-transferase and free fatty acids. The one-year combined exercise/lifestyle program KLAKS significantly improves markers of obesity and glycemic control. Impaired cardiometabolic risk markers, even subclinical, are also favorably influenced by program participation. Copyright © 2014 Elsevier Inc. All rights reserved.

Effects of a renal rehabilitation exercise program in patients with CKD: a randomized, controlled trial.

PubMed

Rossi, Ana P; Burris, Debra D; Lucas, F Leslie; Crocker, Gail A; Wasserman, James C

2014-12-05

Patients with CKD have a high prevalence of cardiovascular disease associated with or exacerbated by inactivity. This randomized, controlled study investigated whether a renal rehabilitation exercise program for patients with stages 3 or 4 CKD would improve their physical function and quality of life. In total, 119 adults with CKD stages 3 and 4 were randomized, and 107 of these patients proceeded to usual care or the renal rehabilitation exercise intervention consisting of usual care plus guided exercise two times per week for 12 weeks (24 sessions). Physical function was determined by three well established performance-based tests: 6-minute walk test, sit-to-stand test, and gait-speed test. Health-related quality of life was assessed by the RAND 36-Item Short Form Health Survey. At baseline, no differences in self-reported level of activity, 6-minute walk test, and sit-to-stand test scores were observed between the usual care (n=48) and renal rehabilitation exercise (n=59) groups, although baseline gait-speed test score was higher in the renal rehabilitation exercise group (P<0.001). At follow-up, the renal rehabilitation exercise group but not the usual care group showed significant improvements in the 6-minute walk test (+210.4±266.0 ft [19% improvement] versus -10±219.9 ft; P<0.001), the sit-to-stand test (+26.9±27% of age prediction [29% improvement] versus +0.7±12.1% of age prediction; P<0.001), and the RAND-36 physical measures of role functioning (P<0.01), physical functioning (P<0.01), energy/fatigue levels (P=0.01), and general health (P=0.03) and mental measure of pain scale (P=0.04). The renal rehabilitation exercise regimen was generally well tolerated. A 12-week/24-session renal rehabilitation exercise program improved physical capacity and quality of life in patients with CKD stages 3 and 4. Longer follow-up is needed to determine if these findings will translate into decreased mortality rates. Copyright © 2014 by the American Society of Nephrology.

Effects of aging and exercise training on spinotrapezius muscle microvascular Po2 dynamics and vasomotor control

PubMed Central

McCullough, Danielle J.; Davis, Robert T.; Dominguez, James M.; Stabley, John N.; Bruells, Christian S.

2011-01-01

With advancing age, there is a reduction in exercise tolerance, resulting, in part, from a perturbed ability to match O2 delivery to uptake within skeletal muscle. In the spinotrapezius muscle (which is not recruited during incline treadmill running) of aged rats, we tested the hypotheses that exercise training will 1) improve the matching of O2 delivery to O2 uptake, evidenced through improved microvascular Po2 (PmO2), at rest and throughout the contractions transient; and 2) enhance endothelium-dependent vasodilation in first-order arterioles. Young (Y, ∼6 mo) and aged (O, >24 mo) Fischer 344 rats were assigned to control sedentary (YSED; n = 16, and OSED; n = 15) or exercise-trained (YET; n = 14, and OET; n = 13) groups. Spinotrapezius blood flow (via radiolabeled microspheres) was measured at rest and during exercise. Phosphorescence quenching was used to quantify PmO2 in vivo at rest and across the rest-to-twitch contraction (1 Hz, 5 min) transition in the spinotrapezius muscle. In a follow-up study, vasomotor responses to endothelium-dependent (acetylcholine) and -independent (sodium nitroprusside) stimuli were investigated in vitro. Blood flow to the spinotrapezius did not increase above resting values during exercise in either young or aged groups. Exercise training increased the precontraction baseline PmO2 (OET 37.5 ± 3.9 vs. OSED 24.7 ± 3.6 Torr, P < 0.05); the end-contracting PmO2 and the time-delay before PmO2 fell in the aged group but did not affect these values in the young. Exercise training improved maximal vasodilation in aged rats to acetylcholine (OET 62 ± 16 vs. OSED 27 ± 16%) and to sodium nitroprusside in both young and aged rats. Endurance training of aged rats enhances the PmO2 in a nonrecruited skeletal muscle and is associated with improved vascular smooth muscle function. These data support the notion that improvements in vascular function with exercise training are not isolated to the recruited muscle. PMID:21212242

Subcutaneous inguinal white adipose tissue is responsive to, but dispensable for, the metabolic health benefits of exercise.

PubMed

Peppler, Willem T; Townsend, Logan K; Knuth, Carly M; Foster, Michelle T; Wright, David C

2018-01-01

Exercise training has robust effects on subcutaneous inguinal white adipose tissue (iWAT), characterized by a shift to a brown adipose tissue (BAT)-like phenotype. Consistent with this, transplantation of exercise-trained iWAT into sedentary rodents activates thermogenesis and improves glucose homeostasis, suggesting that iWAT metabolism may contribute to the beneficial effects of exercise. However, it is yet to be determined if adaptations in iWAT are necessary for the beneficial systemic effects of exercise. To test this, male C57BL/6 mice were provided access to voluntary wheel running (VWR) or remained as a cage control (SED) for 11 nights after iWAT removal via lipectomy (LIPX) or SHAM surgery. We found that SHAM and LIPX mice with access to VWR ran similar distances and had comparable reductions in body mass, increased food intake, and increased respiratory exchange ratio (RER). Further, VWR improved indexes of glucose homeostasis and insulin tolerance in both SHAM and LIPX mice. The lack of effect of LIPX in the response to VWR was not explained by compensatory increases in markers of mitochondrial biogenesis and thermogenesis in skeletal muscle, epididymal white adipose tissue, or interscapular brown adipose tissue. Together, these data demonstrate that mice with and without iWAT have comparable adaptations to VWR, suggesting that iWAT may be dispensable for the metabolic health benefits of exercise.

Endurance exercise in a rat model of metabolic syndrome.

PubMed

Cameron, Isabelle; Alam, Mohammad Ashraful; Wang, Jianxiong; Brown, Lindsay

2012-11-01

We have measured the responses to endurance exercise training on body composition and glucose regulation, as well as cardiovascular and liver structure and function in rats fed a high carbohydrate and high fat (HCHF) diet as a model of human metabolic syndrome. Male Wistar rats (9-10 weeks old) were randomly allocated into corn starch (CS) or HCHF diet groups for 16 weeks; half of each group were exercised on a treadmill for 20, 25, and then 30 min/day, 5 days/week, during the last 8 weeks of the protocol. Metabolic, cardiovascular, and liver parameters were monitored. The HCHF diet induced symptoms of metabolic syndrome, including obesity, dyslipidemia, impaired glucose tolerance, and increased systolic blood pressure associated with the development of cardiovascular remodeling and nonalcoholic steatohepatitis. Exercise in HCHF rats decreased body mass, abdominal fat pads and circumference, blood glucose concentrations, plasma lipid profiles, systolic blood pressure, left ventricular diastolic stiffness, collagen deposition and inflammatory cell infiltration in the left ventricle, improved aortic contractile and relaxation responses, and decreased liver mass and hepatic fat accumulation. This study demonstrates that endurance exercise is effective in this rat model of diet-induced metabolic syndrome in improving body composition and glucose regulation, as well as cardiovascular and liver structure and function.

Acute and chronic hypoxia: implications for cerebral function and exercise tolerance

PubMed Central

Goodall, Stuart; Twomey, Rosie; Amann, Markus

2015-01-01

Purpose To outline how hypoxia profoundly affects neuronal functionality and thus compromise exercise-performance. Methods Investigations using electroencephalography (EEG) and transcranial magnetic stimulation (TMS) detecting neuronal changes at rest and those studying fatiguing effects on whole-body exercise performance in acute (AH) and chronic hypoxia (CH) were evaluated. Results At rest during very early hypoxia (<1-h), slowing of cerebral neuronal activity is evident despite no change in corticospinal excitability. As time in hypoxia progresses (3-h), increased corticospinal excitability becomes evident; however, changes in neuronal activity are unknown. Prolonged exposure (3–5 d) causes a respiratory alkalosis which modulates Na+ channels, potentially explaining reduced neuronal excitability. Locomotor exercise in AH exacerbates the development of peripheral-fatigue; as the severity of hypoxia increases, mechanisms of peripheral-fatigue become less dominant and CNS hypoxia becomes the predominant factor. The greatest central-fatigue in AH occurs when SaO2 is ≤75%, a level that coincides with increasing impairments in neuronal activity. CH does not improve the level of peripheral-fatigue observed in AH; however, it attenuates the development of central-fatigue paralleling increases in cerebral O2 availability and corticospinal excitability. Conclusions The attenuated development of central-fatigue in CH might explain, the improvements in locomotor exercise-performance commonly observed after acclimatisation to high altitude. PMID:25593787

Effects of active/passive interventions on pain, anxiety, and quality of life in women with fibromyalgia: Randomized controlled pilot trial.

PubMed

Ekici, Gamze; Unal, Edibe; Akbayrak, Turkan; Vardar-Yagli, Naciye; Yakut, Yavuz; Karabulut, Erdem

2017-01-01

The authors of this study compared the effects of pilates exercises and connective tissue massage (CTM) on pain intensity; pain-pressure threshold; and tolerance, anxiety, progress, and health-related quality of life in females with fibromyalgia. It was a pilot, assessor masked, randomized controlled trial conducted between January and August of 2013. Twenty-one women with fibromyalgia were randomly assigned to the pilates exercise program (six of whom did not complete the program), and 22 were randomly assigned to CTM (one of whom did not complete this program). Each group received the assigned intervention three times per week during a 4-week period. The Visual Analogue Scale, algometry, State-Trait Anxiety Inventory, Fibromyalgia Impact Questionnaire, and Nottingham Health Profile were used at baseline and at the end of treatments. Significant improvements were found in both groups for all parameters. However, the scores for pain-pressure threshold were significantly elevated and the symptoms of anxiety were significantly diminished in the exercise group compared to the massage group. Thus, exercise and massage might be used to provide improvements in women with fibromyalgia. The exercise group showed more advantages than the massage group and thus might be preferred for patients with fibromyalgia. However, an adequately powered trial is required to determine this with certainty.

The effects of high intensity interval training in women with rheumatic disease: a pilot study.

PubMed

Sandstad, Janne; Stensvold, Dorthe; Hoff, Mari; Nes, Bjarne M; Arbo, Ingerid; Bye, Anja

2015-10-01

Rheumatoid arthritis (RA) and juvenile idiopathic arthritis (JIA) are inflammatory diseases which involve increased risk of cardiovascular disease (CVD). High intensity interval training (HIIT) is known to be effective in improving cardiovascular health. The aim of this study was to investigate whether 10 weeks of HIIT at 85-95% of HRmax would improve important risk factors of CVD in rheumatic patients, and if these patients would tolerate exercise intensities above today's recommendations. Seven women with RA and eleven with adult-JIA, 20-50 years, were recruited to this cross-over study. Participants performed HIIT, consisting of 4 × 4 min intervals at 85-95% of HRmax twice a week for 10 weeks on spinning bikes. Maximal oxygen uptake (VO2max), heart rate recovery, blood pressure, body composition, and blood variables were measured before and after the exercise and control period. Disease activity was determined and questionnaire data were collected. HIIT resulted in 12.2% increase in VO2max and 2.9% improvement in heart rate recovery (p < 0.05). BMI, body fat, and waist circumference decreased 1.2, 1.0, and 1.6%, respectively, whereas muscle mass increased 0.6% (p < 0.05). A trend toward decreased CRP was detected after HIIT (p = 0.08). No changes were detected in disease activity or pain. Despite rigorous high intensity exercise, no increase was detected in disease activity or pain, indicating that HIIT was well tolerated by these patients. Furthermore, HIIT had positive effects on several CVD risk factors. In light of this pilot study, HIIT seems like a promising non-pharmacological treatment strategy for patients with RA and adult-JIA.

An integrated programme after pulmonary rehabilitation in patients with chronic obstructive pulmonary disease: effect on emotional and functional dimensions of quality of life.

PubMed

Moullec, G; Ninot, G

2010-02-01

To assess whether a maintenance integrated health care programme is effective in improving functional and emotional dimensions of quality of life in patients with chronic obstructive pulmonary disease (COPD) after a first pulmonary rehabilitation. Prospective controlled trial. Three rehabilitation centres and three patient self-help associations within a health care network in France. Forty patients with moderate to severe COPD. After a first four-week inpatient pulmonary rehabilitation programme, patients took part in a maintenance integrated health care programme or usual care for 12 months. The primary outcomes were the change in functional and emotional dimensions of quality of life measured by the St George's Respiratory Questionnaire (SGRQ), the brief World Health Organization Quality of Life questionnaire (Brief-WHOQOL) and six specific questions using a 10-cm visual analogue scale. Secondary outcomes were change in exercise tolerance measured by six-minute walking test and cycle exercise. At one year, the maintenance intervention (n = 11) produced improvements in functional and emotional dimensions scores of quality of life and exercise tolerance. Patients in the usual aftercare group (n = 16) exhibited maintenance of functional dimension scores of quality of life, but a clinically relevant decline in emotional scores of quality of life and in six-minute walking distance one year after the pulmonary rehabilitation. Patient self-help association seems to be an innovative and efficient organizational structure to support patients with COPD after pulmonary rehabilitation in real-life settings. A distinction between emotional and functional dimensions of quality of life may improve the design and evaluation of integrated health care programmes in patients with COPD.

Exercise training during normobaric hypoxic confinement does not alter hormonal appetite regulation.

PubMed

Debevec, Tadej; Simpson, Elizabeth J; Macdonald, Ian A; Eiken, Ola; Mekjavic, Igor B

2014-01-01

Both exposure to hypoxia and exercise training have the potential to modulate appetite and induce beneficial metabolic adaptations. The purpose of this study was to determine whether daily moderate exercise training performed during a 10-day exposure to normobaric hypoxia alters hormonal appetite regulation and augments metabolic health. Fourteen healthy, male participants underwent a 10-day hypoxic confinement at ∼ 4000 m simulated altitude (FIO2 = 0.139 ± 0.003%) either combined with daily moderate intensity exercise (Exercise group; N = 8, Age = 25.8 ± 2.4 yrs, BMI = 22.9 ± 1.2 kg · m(-2)) or without any exercise (Sedentary group; N = 6 Age = 24.8 ± 3.1 yrs, BMI = 22.3 ± 2.5 kg · m(-2)). A meal tolerance test was performed before (Pre) and after the confinement (Post) to quantify fasting and postp randial concentrations of selected appetite-related hormones and metabolic risk markers. 13C-Glucose was dissolved in the test meal and 13CO2 determined in breath samples. Perceived appetite ratings were obtained throughout the meal tolerance tests. While body mass decreased in both groups (-1.4 kg; p = 0.01) following the confinement, whole body fat mass was only reduced in the Exercise group (-1.5 kg; p = 0.01). At Post, postprandial serum insulin was reduced in the Sedentary group (-49%; p = 0.01) and postprandial plasma glucose in the Exercise group (-19%; p = 0.03). Fasting serum total cholesterol levels were reduced (-12%; p = 0.01) at Post in the Exercise group only, secondary to low-density lipoprotein cholesterol reduction (-16%; p = 0.01). No differences between groups or testing periods were noted in fasting and/or postprandial concentrations of total ghrelin, peptide YY, and glucagon-like peptide-1, leptin, adiponectin, expired 13CO2 as well as perceived appetite ratings (p>0.05). These findings suggest that performing daily moderate intensity exercise training during continuous hypoxic exposure does not alter hormonal appetite regulation but can improve the lipid profile in healthy young males.

Influence of Disease Severity and Exercise Limitation on Exercise Training Intensity and Load and Health Benefits From Pulmonary Rehabilitation in Patients with COPD: AN EXPLORATORY STUDY.

PubMed

Huynh, Virginia C; Fuhr, Desi P; Byers, Bradley W; Selzler, Anne-Marie; Moore, Linn E; Stickland, Michael K

2018-04-11

Some patients with chronic obstructive pulmonary disease (COPD) fail to achieve health benefits with pulmonary rehabilitation (PR). Exercise intensity and load represent stimulus for adaptation but it is unclear whether inappropriate exercise intensity and/or load are affected by severity of COPD, which may affect health benefits. The purpose was to determine whether COPD severity and/or the severity of pulmonary limitation to exercise (PLE) impacted exercising intensity or load and whether resultant intensity/load affected health outcomes derived from PR. Patients with COPD (n = 58, age = 67 ± 7 y, forced expiratory volume in the first second of expiration [FEV1] % predicted = 52 ± 21%) were recruited upon referral to PR. Primary health outcomes evaluated were 6-min walk distance and St George's Respiratory Questionnaire. Patients were stratified for disease severity using Global Initiative for Obstructive Lung Disease (GOLD) staging and PLE severity by change in inspiratory capacity during exercise. Exercise intensity and load were calculated from daily exercise records. Participants achieved comparable training duration and load regardless of GOLD severity. Patients with more severe PLE achieved greater training duration (more severe: 546 ± 143 min., less severe: 451 ± 109 min., P = .036), and relative training load (more severe: 2200.8 ± 595.3 kcal, less severe: 1648.3 ± 597.8 kcal, P = .007). Greater overall training load was associated with greater improvements in 6-min walk distance (r = 0.24, P = .035). No significant relationships were observed between PLE, GOLD severity, training parameters, and St George's Respiratory Questionnaire response. Improvements in exercise tolerance can be explained by achieving greater training loads, demonstrating the importance of appropriate training load to maximize health outcomes in PR.

Vitamin E and vitamin C do not reduce insulin sensitivity but inhibit mitochondrial protein expression in exercising obese rats

PubMed Central

Picklo, Matthew J.; Thyfault, John P.

2016-01-01

Controversy exists as to whether supplementation with the antioxidants vitamin E and vitamin C blocks adaptation to exercise. Exercise is a first-line means to treat obesity and its complications. While diet-induced obesity alters mitochondrial function and induces insulin resistance (IR), no data exist as to whether supplementation with vitamin E and vitamin C modify responses to exercise in pre-existing obesity. We tested the hypothesis that dietary supplementation with vitamin E (0.4 g α-tocopherol acetate/kg) and vitamin C (0.5 g/kg) blocks exercise-induced improvements on IR and mitochondrial content in obese rats maintained on a high-fat (45% fat energy (en)) diet. Diet-induced obese, sedentary rats had a 2-fold higher homeostasis model assessment of insulin resistance and larger insulin area under the curve following glucose tolerances test than rats fed a low-fat (10% fat en) diet. Exercising (12 weeks at 5 times per week in a motorized wheel) of obese rats normalized IR indices, an effect not modified by vitamin E and vitamin C. Vitamin E and vitamin C supplementation with exercise elevated mtDNA content in adipose and skeletal muscle to a greater extent (20%) than exercise alone in a depot-specific manner. On the other hand, vitamin C and vitamin E decreased exercise-induced increases in mitochondrial protein content for complex I (40%) and nicotinamide nucleotide transhydrogenase (35%) in a muscle-dependent manner. These data indicate that vitamin E and vitamin C supplementation in obese rodents does not modify exercise-induced improvements in insulin sensitivity but that changes in mitochondrial biogenesis and mitochondrial protein expression may be modified by antioxidant supplementation. PMID:25761734

Neuromuscular electrical stimulation improves exercise tolerance in patients with advanced heart failure on continuous intravenous inotropic support use-randomized controlled trial.

PubMed

Forestieri, Patrícia; Bolzan, Douglas W; Santos, Vinícius B; Moreira, Rita Simone Lopes; de Almeida, Dirceu Rodrigues; Trimer, Renata; de Souza Brito, Flávio; Borghi-Silva, Audrey; de Camargo Carvalho, Antonio Carlos; Arena, Ross; Gomes, Walter J; Guizilini, Solange

2018-01-01

To evaluate the impact of a short-term neuromuscular electrical stimulation program on exercise tolerance in hospitalized patients with advanced heart failure who have suffered an acute decompensation and are under continuous intravenous inotropic support. A randomized controlled study. Initially, 195 patients hospitalized for decompensated heart failure were recruited, but 70 were randomized. Patients were randomized into two groups: control group subject to the usual care ( n = 35); neuromuscular electrical stimulation group ( n = 35) received daily training sessions to both lower extremities for around two weeks. The baseline 6-minute walk test to determine functional capacity was performed 24 hours after hospital admission, and intravenous inotropic support dose was daily checked in all patients. The outcomes were measured in two weeks or at the discharge if the patients were sent back home earlier than two weeks. After losses of follow-up, a total of 49 patients were included and considered for final analysis (control group, n = 25 and neuromuscular electrical stimulation group, n = 24). The neuromuscular electrical stimulation group presented with a higher 6-minute walk test distance compared to the control group after the study protocol (293 ± 34.78 m vs. 265.8 ± 48.53 m, P < 0.001, respectively). Neuromuscular electrical stimulation group also demonstrated a significantly higher dose reduction of dobutamine compared to control group after the study protocol (2.72 ± 1.72 µg/kg/min vs. 3.86 ± 1.61 µg/kg/min, P = 0.001, respectively). A short-term inpatient neuromuscular electrical stimulation rehabilitation protocol improved exercise tolerance and reduced intravenous inotropic support necessity in patients with advanced heart failure suffering a decompensation episode.

Prediction of exercise-mediated changes in metabolic markers by gene polymorphism.

PubMed

Kahara, Toshio; Takamura, Toshinari; Hayakawa, Tetsuo; Nagai, Yukihiro; Yamaguchi, Hiromi; Katsuki, Tatsuo; Katsuki, Ken-ichi; Katsuki, Michio; Kobayashi, Ken-ichi

2002-08-01

The effects of regular physical exercise on obesity-associated metabolic abnormalities vary for each individual. In this study, we investigated whether genotypes of genes associated with obesity can predict the effects of exercise on changes in metabolic markers in healthy men. Healthy Japanese men (n=106) performed the exercise program at 50% of their maximal heart rate for 20-60 min a day, 2-3 days each week for 3 months. The levels of fasting plasma glucose (FPG) and serum leptin significantly decreased after the exercise program. Polymorphisms of the beta3-adrenergic receptor (beta3AR) and uncoupling protein-1 (UCP-1) genes were analyzed with RFLP methods. In the Trp/Trp genotype of the beta3AR gene, the levels of serum leptin, FPG and fructosamine (FrAm) decreased significantly after the exercise program, but not in the Arg/Arg genotype. In the AG heterozygote and the GG homozygote of the UCP-1 gene, FPG and FrAm levels were significantly reduced, respectively. In conclusion, gene polymorphism of the beta3AR and UCP-1 was found to be associated with the exercise-mediated improvement in glucose tolerance and leptin resistance in healthy Japanese men.

Increasing physical activity and exercise in lung cancer: reviewing safety, benefits, and application.

PubMed

Bade, Brett C; Thomas, D David; Scott, JoAnn B; Silvestri, Gerard A

2015-06-01

Lung cancer continues to be a difficult disease frequently diagnosed in late stages with a high mortality and symptom burden. In part because of frequent lung comorbidity, even lung cancer survivors often remain symptomatic and functionally limited. Though targeted therapy continues to increase treatment options for advanced-stage disease, symptom burden remains high with few therapeutic options. In the last several decades, exercise and physical activity have arisen as therapeutic options for obstructive lung disease and lung cancer. To date, exercise has been shown to reduce symptoms, increase exercise tolerance, improve quality of life, and potentially reduce length of stay and postoperative complications. Multiple small trials have been performed in perioperative non-small-cell lung cancer patients, although fewer studies are available for patients with advanced-stage disease. Despite the increased interest in this subject over the last few years, a validated exercise regimen has not been established for perioperative or advanced-stage disease. Clinicians underutilize exercise and pulmonary rehabilitation as a therapy, in part because of the lack of evidence-based consensus as to how and when to implement increasing physical activity. This review summarizes the existing evidence on exercise in lung cancer patients.

Comparison of Different Forms of Exercise Training in Patients With Cardiac Disease: Where Does High-Intensity Interval Training Fit?

PubMed

Gayda, Mathieu; Ribeiro, Paula A B; Juneau, Martin; Nigam, Anil

2016-04-01

In this review, we discuss the most recent forms of exercise training available to patients with cardiac disease and their comparison or their combination (or both) during short- and long-term (phase II and III) cardiac rehabilitation programs. Exercise training modalities to be discussed include inspiratory muscle training (IMT), resistance training (RT), continuous aerobic exercise training (CAET), and high-intensity interval training (HIIT). Particular emphasis is placed on HIIT compared or combined (or both) with other forms such as CAET or RT. For example, IMT combined with CAET was shown to be superior to CAET alone for improving functional capacity, ventilatory function, and quality of life in patients with chronic heart failure. Similarly, RT combined with CAET was shown to optimize benefits with respect to functional capacity, muscle function, and quality of life. Furthermore, in recent years, HIIT has emerged as an alternative or complementary (or both) exercise modality to CAET, providing equivalent if not superior benefits to conventional continuous aerobic training with respect to aerobic fitness, cardiovascular function, quality of life, efficiency, safety, tolerance, and exercise adherence in both short- and long-term training studies. Finally, short-interval HIIT was shown to be useful in the initiation and improvement phases of cardiac rehabilitation, whereas moderate- or longer-interval (or both) HIIT protocols appear to be more appropriate for the improvement and maintenance phases because of their high physiological stimulus. We now propose progressive models of exercise training (phases II-III) for patients with cardiac disease, including a more appropriate application of HIIT based on the scientific literature in the context of a multimodal cardiac rehabilitation program. Copyright © 2016 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

The effects of aerobic, resistance, and combination training on insulin sensitivity and secretion in overweight adults from STRRIDE AT/RT: a randomized trial.

PubMed

AbouAssi, Hiba; Slentz, Cris A; Mikus, Catherine R; Tanner, Charles J; Bateman, Lori A; Willis, Leslie H; Shields, A Tamlyn; Piner, Lucy W; Penry, Lorrie E; Kraus, Erik A; Huffman, Kim M; Bales, Connie W; Houmard, Joseph A; Kraus, William E

2015-06-15

Most health organizations recommend a combination of aerobic training (AT) and resistance training (RT), yet few studies have compared their acute (within 24 h of the last exercise bout) and sustained (after 14 days of no exercise training) effects alone and in combination on glucose metabolism. The present study (Studies Targeting Risk Reduction Interventions through Defined Exercise-Aerobic Training and/or Resistance Training) compared the effects of AT, RT, and the combination (AT/RT) on insulin action at both acute and sustained phases. Subjects (N = 196) were 18-70 yr old (mean age = 50 yr), overweight (mean body mass index = 30 kg/m2), sedentary with moderate dyslipidemia, and were randomized into one of three 8-mo exercise groups: 1) RT: 3 days/wk, 8 exercises, 3 sets/exercise, 8-12 repetitions/set; 2) AT: equivalent to ∼19.2 km/wk (12 miles/wk) at 75% peak O2 consumption; 3) AT/RT: the combination of AT and RT. One hundred forty-four subjects completed the intervention. Eighty-eight subjects completed all pre- and postintervention testing visits. Insulin sensitivity, glucose effectiveness, and disposition index were measured via a frequently sampled intravenous glucose tolerance test with subsequent minimal model analyses. AT/RT resulted in greater improvements in insulin sensitivity, β-cell function (disposition index), and glucose effectiveness than either AT or RT alone (all P < 0.05). Approximately 52% of the improvement in insulin sensitivity by AT/RT was retained 14 days after the last exercise training bout. Neither AT or RT led to acute or chronic improvement in sensitivity index. In summary, only AT/RT (which required twice as much time as either alone) led to significant acute and sustained benefits in insulin sensitivity

Dietary nitrate supplementation improves team sport-specific intense intermittent exercise performance.

PubMed

Wylie, Lee J; Mohr, Magni; Krustrup, Peter; Jackman, Sarah R; Ermιdis, Georgios; Kelly, James; Black, Matthew I; Bailey, Stephen J; Vanhatalo, Anni; Jones, Andrew M

2013-07-01

Recent studies have suggested that dietary inorganic nitrate (NO₃(-)) supplementation may improve muscle efficiency and endurance exercise tolerance but possible effects during team sport-specific intense intermittent exercise have not been examined. We hypothesized that NO₃(-) supplementation would enhance high-intensity intermittent exercise performance. Fourteen male recreational team-sport players were assigned in a double-blind, randomized, crossover design to consume 490 mL of concentrated, nitrate-rich beetroot juice (BR) and nitrate-depleted placebo juice (PL) over ~30 h preceding the completion of a Yo-Yo intermittent recovery level 1 test (Yo-Yo IR1). Resting plasma nitrite concentration ([NO₂(-)]) was ~400% greater in BR compared to PL. Plasma [NO₂(-)] declined by 20% in PL (P < 0.05) and by 54 % in BR (P < 0.05) from pre-exercise to end-exercise. Performance in the Yo-Yo IR1 was 4.2% greater (P < 0.05) with BR (1,704 ± 304 m) compared to PL (1,636 ± 288 m). Blood [lactate] was not different between BR and PL, but the mean blood [glucose] was lower (3.8 ± 0.8 vs. 4.2 ± 1.1 mM, P < 0.05) and the rise in plasma [K(+)] tended to be reduced in BR compared to PL (P = 0.08). These findings suggest that NO₃(-) supplementation may promote NO production via the nitrate-nitrite-NO pathway and enhance Yo-Yo IR1 test performance, perhaps by facilitating greater muscle glucose uptake or by better maintaining muscle excitability. Dietary NO₃(-) supplementation improves performance during intense intermittent exercise and may be a useful ergogenic aid for team sports players.

Should we treat obesity in COPD? The effects of diet and resistance exercise training.

PubMed

McDonald, Vanessa M; Gibson, Peter G; Scott, Hayley A; Baines, Penelope J; Hensley, Michael J; Pretto, Jeffrey J; Wood, Lisa G

2016-07-01

Obesity is an established risk factor for poor health outcomes, but paradoxically in chronic obstructive pulmonary disease (COPD), it is associated with improved survival and lung function. A major evidence gap exisits to inform treatment recommendations for patients with COPD who are obese. We aimed to determine the effect of weight reduction involving a low-energy diet utilizing a partial meal replacement plan, coupled with resistance exercise training in obese COPD patients. In a proof of concept before-after clinical trial, obese (body mass index ≥30 kg/m(2) ) COPD patients received a 12 week weight reduction programme involving meal replacements, dietary counselling by a dietitian and resistance exercise training prescribed and supervised by a physiotherapist. Patients were reviewed face to face by the dietitian and physiotherapist every 2 weeks for counselling. Twenty-eight participants completed the intervention. Mean (standard deviation) body mass index was 36.3 kg/m(2) (4.6) at baseline and reduced by 2.4 kg/m(2) ((1.1) P < 0.0001) after the intervention. Importantly, skeletal muscle mass was maintained. Clinical outcomes improved with weight loss including exercise capacity, health status, dyspnea, strength and functional outcomes. There was also a significant reduction in the body mass index, obstruction, dyspnea and exercise score (BODE). Systemic inflammation measured by C-reactive protein however did not change. In obese COPD patients, dietary energy restriction coupled with resistance exercise training results in clinically significant improvements in body mass index, exercise tolerance and health status, whilst preserving skeletal muscle mass. This novel study provides a framework for development of guidelines for the management of obese COPD patients and in guiding future research. © 2016 Asian Pacific Society of Respirology.

Weight Loss, Exercise, or Both and Cardiometabolic Risk Factors in Obese Older Adults: Results of a Randomized Controlled Trial

PubMed Central

Bouchonville, Matthew; Armamento-Villareal, Reina; Shah, Krupa; Napoli, Nicola; Sinacore, David R.; Qualls, Clifford; Villareal, Dennis T.

2013-01-01

Background Obesity exacerbates the age-related decline in insulin sensitivity and is associated with risk for cardiometabolic syndrome in older adults; however, the appropriate treatment for obese older adults is controversial. Objective To determine the independent and combined effects of weight loss and exercise on cardiometabolic risk factors in obese older adults. Design One-hundred-seven obese (BMI≥30 kg/m2) older (≥65 yrs) adults with physical frailty were randomized to control group, diet group, exercise group, and diet-exercise group for 1 year. Outcomes for this study included change in insulin sensitivity index (ISI), glucose tolerance, central obesity, adipocytokines, and cardiometabolic syndrome. Results Although similar increases in ISI occurred in the diet-exercise and diet groups at 6 months, the ISI improved more in the diet-exercise than in the diet group at 12 months (2.4 vs. 1.2; between-group difference, 1.2; 95% CI, 0.2-2.1); no changes in ISI occurred in both exercise and control groups. The diet-exercise and diet groups had similar improvements in insulin area under the curve (AUC) (−2.9 and −2.9 ×103mg.min/dl), glucose AUC (−1.4 and −2.2×103mg.min/dl), visceral fat (−787 and −561 cm3), tumor-necrosis factor (−17.0 and −12.8 pg/mL), adiponectin (5.0 and 4.0 ng/mL), waist circumference (−8.2 and −8.4 cm), triglyceride (−30.7 and −24.3 g/dL), and systolic/diastolic BP (−15.9 and −13.1/−4.9 and −6.7 mmHg), while no changes in these parameters occurred in both exercise and control groups. The cardiometabolic syndrome prevalence decreased by 40% in the diet-exercise and by 15% in the diet group. Body weight decreased similarly in the diet-exercise and diet groups (−8.6 and −9.7kg) but not in the exercise and control groups. Conclusions In frail, obese older adults, lifestyle interventions associated with weight loss improve insulin sensitivity and other cardiometabolic risk factors, but continued improvement in insulin sensitivity is only achieved when exercise training is added to weight loss. PMID:23823329

Inefficient skeletal muscle oxidative function flanks impaired motor neuron recruitment in Amyotrophic Lateral Sclerosis during exercise.

PubMed

Lanfranconi, F; Ferri, A; Corna, G; Bonazzi, R; Lunetta, C; Silani, V; Riva, N; Rigamonti, A; Maggiani, A; Ferrarese, C; Tremolizzo, L

2017-06-07

This study aimed to evaluate muscle oxidative function during exercise in amyotrophic lateral sclerosis patients (pALS) with non-invasive methods in order to assess if determinants of reduced exercise tolerance might match ALS clinical heterogeneity. 17 pALS, who were followed for 4 months, were compared with 13 healthy controls (CTRL). Exercise tolerance was assessed by an incremental exercise test on cycle ergometer measuring peak O 2 uptake ([Formula: see text]O 2peak ), vastus lateralis oxidative function by near infrared spectroscopy (NIRS) and breathing pattern ([Formula: see text]E peak ). pALS displayed: (1) 44% lower [Formula: see text]O 2peak vs. CTRL (p < 0.0001), paralleled by a 43% decreased peak skeletal muscle oxidative function (p < 0.01), with a linear regression between these two variables (r 2  = 0.64, p < 0.0001); (2) 46% reduced [Formula: see text]E peak vs. CTRL (p < 0.0001), achieved by using an inefficient breathing pattern (increasing respiratory frequency) from the onset until the end of exercise. Inefficient skeletal muscle O 2 function, when flanking the impaired motor units recruitment, is a major determinant of pALS clinical heterogeneity and working capacity exercise tolerance. CPET and NIRS are useful tools for detecting early stages of oxidative deficiency in skeletal muscles, disclosing individual impairments in the O 2 transport and utilization chain.

Preventive strength training improves working ergonomics during welding.

PubMed

Krüger, Karsten; Petermann, Carmen; Pilat, Christian; Schubert, Emil; Pons-Kühnemann, Jörn; Mooren, Frank C

2015-01-01

To investigate the effect of a preventive strength training program on cardiovascular, metabolic and muscular strains during welding. Welders are one of the occupation groups which typically have to work in extended forced postures which are known to be an important reason for musculoskeletal disorders. Subjects (exercise group) accomplished a 12-week strength training program, while another group served as controls (control group). Pre and post training examinations included the measurements of the one repetition maximum and an experimental welding test. Local muscle activities were analysed by surface electromyography. Furthermore, heart rate, blood pressure, lactate and rating of perceived exertion were examined. In the exercise group, strength training lead to a significant increase of one repetition maximum in all examined muscles (p<.05). During the experimental welding test muscle activities of trunk and shoulder muscles and arm muscles were significantly reduced in the exercise group after intervention (p<.05). While no changes of neither cardiovascular nor metabolic parameters were found, subjects of the exercise group rated a significantly decreased rate of perceived exertion welding (p<.05). Effects of strength training can be translated in an improved working ergonomics and tolerance against the exposure to high physical demands at work.

Prefrontal oxygenation and the acoustic startle eyeblink response during exercise: A test of the dual-mode model.

PubMed

Tempest, Gavin D; Parfitt, Gaynor

2017-07-01

The interplay between the prefrontal cortex and amygdala is proposed to explain the regulation of affective responses (pleasure/displeasure) during exercise as outlined in the dual-mode model. However, due to methodological limitations the dual-mode model has not been fully tested. In this study, prefrontal oxygenation (using near-infrared spectroscopy) and amygdala activity (reflected by eyeblink amplitude using acoustic startle methodology) were recorded during exercise standardized to metabolic processes: 80% of ventilatory threshold (below VT), at the VT, and at the respiratory compensation point (RCP). Self-reported tolerance of the intensity of exercise was assessed prior to, and affective responses recorded during exercise. The results revealed that, as the intensity of exercise became more challenging (from below VT to RCP), prefrontal oxygenation was larger and eyeblink amplitude and affective responses were reduced. Below VT and at VT, larger prefrontal oxygenation was associated with larger eyeblink amplitude. At the RCP, prefrontal oxygenation was greater in the left than right hemisphere, and eyeblink amplitude explained significant variance in affective responses (with prefrontal oxygenation) and self-reported tolerance. These findings highlight the role of the prefrontal cortex and potentially the amygdala in the regulation of affective (particularly negative) responses during exercise at physiologically challenging intensities (above VT). In addition, a psychophysiological basis of self-reported tolerance is indicated. This study provides some support of the dual-mode model and insight into the neural basis of affective responses during exercise. © 2017 Society for Psychophysiological Research.

Exercise Tolerance Testing in a Prospective Cohort of Adolescents with Chronic Fatigue Syndrome and Recovered Controls Following Infectious Mononucleosis

PubMed Central

Katz, Ben Z.; Boas, Steven; Shiraishi, Yukiko; Mears, Cynthia J.; Taylor, Renee

2010-01-01

Objective Six months following acute infectious mononucleosis (IM), 13%, of adolescents meet criteria for chronic fatigue syndrome (CFS). We measured exercise tolerance in adolescents with CFS and controls 6 months following IM. Study design 21 adolescents with CFS 6 months following IM and 21 recovered controls performed a maximal incremental exercise tolerance test with breath-by-breath gas analysis. Values expressed are mean ± standard deviation. Results The adolescents diagnosed with CFS and controls did not differ in age, weight, body-mass index or peak work capacity. Lower VO2 (oxygen consumption) peak percent of predicted was seen in adolescents with CFS compared with controls (CFS 99.3 ± 16.6 vs control 110.7 ± 19.9, p = 0.05). Peak oxygen pulse also was lower in adolescents with CFS compared with recovered controls (CFS 12.4 ± 2.9 vs controls 14.9 ± 4.3, p = 0.03). Conclusions Adolescents with CFS 6 months following IM have a lower degree of fitness and efficiency of exercise than recovered adolescents. Whether these abnormal exercise findings are a cause or effect of CFS is unknown. IM can lead to both fatigue and measurable changes in exercise testing in a subset of adolescents. PMID:20447647

Improved Exercise Tolerance with Caffeine Is Associated with Modulation of both Peripheral and Central Neural Processes in Human Participants.

PubMed

Bowtell, Joanna L; Mohr, Magni; Fulford, Jonathan; Jackman, Sarah R; Ermidis, Georgios; Krustrup, Peter; Mileva, Katya N

2018-01-01

Caffeine has been shown to enhance exercise performance and capacity. The mechanisms remain unclear but are suggested to relate to adenosine receptor antagonism, resulting in increased central motor drive, reduced perception of effort, and altered peripheral processes such as enhanced calcium handling and extracellular potassium regulation. Our aims were to investigate how caffeine (i) affects knee extensor PCr kinetics and pH during repeated sets of single-leg knee extensor exercise to task failure and (ii) modulates the interplay between central and peripheral neural processes. We hypothesized that the caffeine-induced extension of exercise capacity during repeated sets of exercise would occur despite greater disturbance of the muscle milieu due to enhanced peripheral and corticospinal excitatory output, central motor drive, and muscle contractility. Nine healthy active young men performed five sets of intense single-leg knee extensor exercise to task failure on four separate occasions: for two visits (6 mg·kg -1 caffeine vs placebo), quadriceps 31 P-magnetic resonance spectroscopy scans were performed to quantify phosphocreatine kinetics and pH, and for the remaining two visits (6 mg·kg -1 caffeine vs placebo), femoral nerve electrical and transcranial magnetic stimulation of the quadriceps cortical motor area were applied pre- and post exercise. The total exercise time was 17.9 ± 6.0% longer in the caffeine (1,225 ± 86 s) than in the placebo trial (1,049 ± 73 s, p  = 0.016), and muscle phosphocreatine concentration and pH ( p < 0.05) were significantly lower in the latter sets of exercise after caffeine ingestion. Voluntary activation (VA) (peripheral, p  = 0.007; but not supraspinal, p  = 0.074), motor-evoked potential (MEP) amplitude ( p  = 0.007), and contractility (contraction time, p  = 0.009; and relaxation rate, p  = 0.003) were significantly higher after caffeine consumption, but at task failure MEP amplitude and VA were not different from placebo. Caffeine prevented the reduction in M-wave amplitude that occurred at task failure ( p  = 0.039). Caffeine supplementation improved high-intensity exercise tolerance despite greater-end exercise knee extensor phosphocreatine depletion and H + accumulation. Caffeine-induced increases in central motor drive and corticospinal excitability were attenuated at task failure. This may have been induced by the afferent feedback of the greater disturbance of the muscle milieu, resulting in a stronger inhibitory input to the spinal and supraspinal motor neurons. However, causality needs to be established through further experiments.

Insulin sensitivity and metabolic flexibility following exercise training among different obese insulin-resistant phenotypes.

PubMed

Malin, Steven K; Haus, Jacob M; Solomon, Thomas P J; Blaszczak, Alecia; Kashyap, Sangeeta R; Kirwan, John P

2013-11-15

Impaired fasting glucose (IFG) blunts the reversal of impaired glucose tolerance (IGT) after exercise training. Metabolic inflexibility has been implicated in the etiology of insulin resistance; however, the efficacy of exercise on peripheral and hepatic insulin sensitivity or substrate utilization in adults with IFG, IGT, or IFG + IGT is unknown. Twenty-four older (66.7 ± 0.8 yr) obese (34.2 ± 0.9 kg/m(2)) adults were categorized as IFG (n = 8), IGT (n = 8), or IFG + IGT (n = 8) according to a 75-g oral glucose tolerance test (OGTT). Subjects underwent 12-wk of exercise (60 min/day for 5 days/wk at ∼85% HRmax) and were instructed to maintain a eucaloric diet. A euglycemic hyperinsulinemic clamp (40 mU·m(2)·min(-1)) with [6,6-(2)H]glucose was used to determine peripheral and hepatic insulin sensitivity. Nonoxidative glucose disposal and metabolic flexibility [insulin-stimulated respiratory quotient (RQ) minus fasting RQ] were also assessed. Glucose incremental area under the curve (iAUCOGTT) was calculated from the OGTT. Exercise increased clamp-derived peripheral and hepatic insulin sensitivity more in adults with IFG or IGT alone than with IFG + IGT (P < 0.05). Exercise reduced glucose iAUCOGTT in IGT only (P < 0.05), and the decrease in glucose iAUCOGTT was inversely correlated with the increase in peripheral but not hepatic insulin sensitivity (P < 0.01). Increased clamp-derived peripheral insulin sensitivity was also correlated with enhanced metabolic flexibility, reduced fasting RQ, and higher nonoxidative glucose disposal (P < 0.05). Adults with IFG + IGT had smaller gains in clamp-derived peripheral insulin sensitivity and metabolic flexibility, which was related to blunted improvements in postprandial glucose. Additional work is required to assess the molecular mechanism(s) by which chronic hyperglycemia modifies insulin sensitivity following exercise training.

Personalized metabolomics for predicting glucose tolerance changes in sedentary women after high-intensity interval training.

PubMed

Kuehnbaum, Naomi L; Gillen, Jenna B; Gibala, Martin J; Britz-McKibbin, Philip

2014-08-28

High-intensity interval training (HIIT) offers a practical approach for enhancing cardiorespiratory fitness, however its role in improving glucose regulation among sedentary yet normoglycemic women remains unclear. Herein, multi-segment injection capillary electrophoresis-mass spectrometry is used as a high-throughput platform in metabolomics to assess dynamic responses of overweight/obese women (BMI > 25, n = 11) to standardized oral glucose tolerance tests (OGTTs) performed before and after a 6-week HIIT intervention. Various statistical methods were used to classify plasma metabolic signatures associated with post-prandial glucose and/or training status when using a repeated measures/cross-over study design. Branched-chain/aromatic amino acids and other intermediates of urea cycle and carnitine metabolism decreased over time in plasma after oral glucose loading. Adaptive exercise-induced changes to plasma thiol redox and orthinine status were measured for trained subjects while at rest in a fasting state. A multi-linear regression model was developed to predict changes in glucose tolerance based on a panel of plasma metabolites measured for naïve subjects in their untrained state. Since treatment outcomes to physical activity are variable between-subjects, prognostic markers offer a novel approach to screen for potential negative responders while designing lifestyle modifications that maximize the salutary benefits of exercise for diabetes prevention on an individual level.

Effects of regular exercise in management of chronic idiopathic constipation.

PubMed

Meshkinpour, H; Selod, S; Movahedi, H; Nami, N; James, N; Wilson, A

1998-11-01

Regular physical exercise has long been considered in the management of chronic constipation. This recommendation is probably based on the assumption that exercise shortens the transit time through the gastrointestinal tract. However, on the basis of previous studies, the effect of exercise on the transit remains controversial at best. Therefore, it was the goal of the present study to assess the influence of regular physical exercise, what average people may consider routine exercise, in the management of chronic idiopathic constipation. The study population consisted of eight patients, seven women and a man, with chronic idiopathic constipation. They were studied for six weeks, including two weeks of rest and four weeks of regular exercise. Patients had a submaximal exercise test, before and after the exercise period, to determine their rate of perceived exertion (RPE), the target heart rate, and the intensity of exercise they can perform. In addition to their routine daily activities, they exercised 1 hr a day, five days a week according to their performance at the initial exercise tolerance test. They kept a daily activity log and maintained their normal dietary intake during this period. The patients overall physical activity was assessed by a pedometer. They also maintained a diary of the number and consistency of their bowel movements and the amount of straining required for defecation. The impact of exercise on constipation was assessed by utilizing an index that took into consideration all three parameters of bowel function. Results of the study revealed that patients covered 1.8+/-0.33 and 3.24+/-0.28 miles/day in the rest period and during the exercise period, respectively (P = 0.007). The intensity of exercise may have improved the level of training as reflected on the mean maximum time before and after exercise period (P = 0.039). This level of exercise did not improve their constipation indices, which were 9.11+/-0.65 and 8.57+/-1.08 in the rest and exercise periods, respectively (P = 0.68). In conclusion, physical activity, to the extent that people consider "regular exercise," does not play a role in the management of chronic idiopathic constipation.

Exercise Within LBNP to Produce Artificial Gravity

NASA Technical Reports Server (NTRS)

Hargens, Alan R.

1996-01-01

Integrated physiologic countermeasures are needed to maintain orthostatic tolerance after spaceflight or bed rest. We hypothesized that supine exercise during LBNP would prevent bed rest-induced loss of orthostatic tolerance by preventing hemoconcentration. In a study conducted jointly with NASA Johnson Space Center and the University of Texas Medical Branch, Galveston, TX, fifteen male subjects underwent 5 days of 6 deg head-down bed rest: 5 control subjects did not exercise, and 10 performed 30 min/day of supine interval treadmill exercise at intensities up to 90% VO(sub 2peak). We will undertake two 14 day bed-rest studies (6 deg head-down tilt bed rest, HDT) to investigate the mechanism of action and efficacy of our partial vacuum exerciser concept. These 14 day bed rest studies were chosen to simulate current microgravity exposures for Space Shuttle crew members.

Does the study of anaerobic metabolism give quantitative information on left ventricular dysfunction during exercise?

PubMed

Opasich, C; Cobelli, F; Riccardi, G; La Rovere, M T; Calsamiglia, G; Specchia, G

1988-04-01

The anaerobic threshold (AT) has been proposed as an index to assess the functional status of patients with chronic heart failure. The focus of this report was to evaluate in post-myocardial infarction patients the utility of the AT for (a) assessing the severity of exercise-induced left ventricular impairment, (b) determining the responses obtained from different treatments and (c) prescribing exercise training. We found that the AT level was lower in patients with abnormal haemodynamic patterns during exercise. The AT was correlated to different degrees of exercise-induced left ventricular impairment. The nitrate and calcium-antagonist effects have been evaluated in patients with abnormal exercise haemodynamics. The resting and exertional results were in agreement with the vasodilator effects. Moreover, the time from onset of exercise to the appearance of the AT was significantly increased by the treatments. Thus, AT during pharmacological treatments may be a non-invasive useful parameter for assessing their haemodynamic effects. Finally, a 4-week intermittent training programme based on AT level was evaluated in patients with abnormal resting and exertional haemodynamics. The results showed an improvement of the exercise cardiovascular tolerance without negative effects on left ventricular function. Therefore, the AT seems to be useful when prescribing a rational and individualized training programme.

Can Self-Reported Preference for Exercise Intensity Predict Physiologically Defined Self-Selected Exercise Intensity?

ERIC Educational Resources Information Center

Ekkekakis, Panteleimon; Lind, Erik; Joens-Matre, Roxane R.

2006-01-01

Exercise prescription guidelines emphasize the importance of individual preferences for different intensities, but such preferences have not been studied systematically. This study examined the hypothesis that the preference scale of the Preference for and Tolerance of the Intensity of Exercise Questionnaire would predict self-selected exercise…

[Effects of exercise training on ergocycle during hemodialysis in patients with end stage renal disease: relevance of the anaerobic threshold intensity].

PubMed

Besnier, Florent; Laruelle, Eric; Genestier, Sandrine; Gié, Sophie; Vigneau, Cécile; Carré, François

2012-07-01

Chronic kidney failure (CRF) in addition to cardiovascular comorbidities and aging decrease physical activity capacity. An adapted rehabilitation program might be strongly recommended in this population. The aim of the study is to evaluate a 3 months exercise training program with ergocycle at the anaerobic threshold (AT) during dialysis sessions on effort tolerance, quality of life, blood pressure and lipidic disorders. Six patients meanly aged 72 were evaluated before (t(0)) and after (t(3)) the rehabilitation program by: maximal cardiorespiratory ergotest, a 6-Minute Walk Test (6MWT) and 2 quality of life tests: Medical Outcome Survey Short Form 36-items and the Kidney Disease Quality of Life (SF 36, KDQol). Physical activity during dialysis is well tolerated. There was no undesirable event during rehabilitation sessions. The dyspnea and muscular weariness threshold linked to the AT increased meanly by 39% (8.83 ± 0.87 vs. 12.25 ± 1.23 mL/min per kg). Distances walked during 6 MWT increased for all patients (351.83 ± 72.17 vs. 412.80 ± 82 meters) Moreover, physical component scale improved (+4.7), mean systolic blood pressure (-7 mmHg) and mean triglycerides concentration (-19%) decreased. An exercise training program during dialysis sessions with ergocycle and working intensity based on AT seems safe and an effective alternative to improve the effort functional capacity by hemodialysis patients. Copyright © 2011 Association Société de néphrologie. Published by Elsevier SAS. All rights reserved.

Australian association for exercise and sports science position statement on exercise and hypertension.

PubMed

Sharman, James E; Stowasser, Michael

2009-03-01

Hypertension (high blood pressure; BP) is a leading contributor to premature death and disability from cardiovascular disease. Lifestyle modification that includes regular physical activity is often recommended to patients with hypertension as one of the first line treatments for lowering BP, as well as improving overall risk for cardiovascular events. It is recognised that allied health care professionals play an important role in helping patients to achieve BP control by influencing and reinforcing appropriate lifestyle behavior. The minimum amount of exercise that is recommended in patients with hypertension comprises a mix of moderate to vigorous aerobic (endurance) activity (up to 5 days/week) in addition to resistance (strength) training (on 2 or more non-consecutive days/week). However, due to the dose-response relationship between physical activity and health, exercise levels performed beyond the minimum recommendations are expected to confer additional health benefits. Vigorous exercise training is generally safe and well tolerated by most people, including those with hypertension, although some special considerations are required and these are discussed in this review.

Effects of hydraulic resistance circuit training on physical fitness components of potential relevance to +Gz tolerance.

PubMed

Jacobs, I; Bell, D G; Pope, J; Lee, W

1987-08-01

Recent studies carried out in the United States and Sweden have demonstrated that strength training can improve +Gz acceleration tolerance. Based on these findings, the Canadian Forces have introduced a training program for aircrew of high performance aircraft. This report describes the changes in physical fitness components considered relevant to +Gz tolerance after 12 weeks of training with this program. Prior to beginning training, 45 military personnel were tested, but only 20 completed a minimum of 24 training sessions. The following variables were measured in these 20 subjects before and after training: maximal strength of several large muscle groups during isokinetic contractions, maximal aerobic power and an endurance fitness index, maximal anaerobic power, anthropometric characteristics, and maximal expiratory pressure generated during exhalation. Training involved hydraulic resistance circuit training 2-4 times/week. The circuit consisted of 3 consecutive sets at each of 8 stations using Hydra-Gym equipment. The exercise:rest ratio was 20:40 s for the initial 4 training weeks and was then changed to 30:50. After training the changes in anthropometric measurements suggested that lean body mass was increased. Small, but significant, increases were also measured in muscle strength during bench press, biceps curls, squats, knee extension, and knee flexion. Neither maximal anaerobic power (i.e. muscular endurance) nor maximal expiratory pressure were changed after the training. Indices of endurance fitness were also increased in the present study. The relatively small increases in strength are probably due to the design of the exercise:rest ratio which resulted in improved strength and aerobic fitness.(ABSTRACT TRUNCATED AT 250 WORDS)

Unrecognized heart failure and chronic obstructive pulmonary disease (COPD) in frail elderly detected through a near-home targeted screening strategy.

PubMed

van Mourik, Yvonne; Bertens, Loes C M; Cramer, Maarten J M; Lammers, Jan-Willem J; Reitsma, Johannes B; Moons, Karel G M; Hoes, Arno W; Rutten, Frans H

2014-01-01

Reduced exercise tolerance and dyspnea are common in older people, and heart failure (HF) and chronic obstructive pulmonary disease (COPD) are the main causes. We want to determine the prevalence of previously unrecognized HF, COPD, and other chronic diseases in frail older people using a near-home targeted screening strategy. Community-dwelling frail persons aged ≥65 years underwent a 2-step screening strategy. First, they received a questionnaire inquiring about dyspnea and exercise tolerance. Those with exercise intolerance and/or dyspnea were invited to visit their primary care physician's office for a screening program, including medical history taking, physical examination, blood tests, electrocardiography, spirometry, and echocardiography. The final diagnosis of every patient was determined by a panel consisting of 3 physicians. Of the 570 elderly who filled out the questionnaire, 395 (69%) had reduced exercise tolerance or dyspnea. Of these, 389 underwent the screening program: 127 (33.5%, 95% confidence interval, 28.9-38.4%) were newly diagnosed with HF (mainly HF with a preserved ejection fraction [23.5%]), and previously unrecognized COPD was detected in 16.8% (95% confidence interval, 13.4-20.9%). In total, 165 patients (43.9%) received a new diagnosis of either HF, COPD, or both. Other new diagnoses (in 32.7% of the screening program patients) included atrial fibrillation (1.8%), valvular disease (21.4%), (persisting) asthma (3.1%), anemia (12.7%), and thyroid disease (0.6%). No clear explanation for the complaints of 47 patients (12.2%) was found using our strategy. Unrecognized chronic diseases might be detected in community-dwelling frail elderly using a near-home screening strategy that is simple to implement. It remains to be proven, however, whether optimizing treatment of the newly detected diagnoses in this fragile population with multimorbidities and polypharmacy improves quality of life and reduces morbidity and mortality. © Copyright 2014 by the American Board of Family Medicine.

Exercise training with negative pressure ventilation improves exercise capacity in patients with severe restrictive lung disease: a prospective controlled study

PubMed Central

2013-01-01

Background Exercise training is of benefit for patients with restrictive lung disease. However, it tends to be intolerable for those with severe disease. We examined whether providing ventilatory assistance by using negative pressure ventilators (NPV) during exercise training is feasible for such patients and the effects of training. Methods 36 patients with restrictive lung disease were prospectively enrolled for a 12-week multidisciplinary rehabilitation program. During this program, half of them (n:18; 60.3 ± 11.6 years; 6 men; FVC: 32.5 ± 11.7% predicted ) received regular sessions of exercise training under NPV, whilst the 18 others (59.6 ± 12.3 years; 8 men; FVC: 37.7 ± 10.2% predicted) did not. Exercise capacity, pulmonary function, dyspnea and quality of life were measured. The primary endpoint was the between-group difference in change of 6 minute-walk distance (6MWD) after 12 weeks of rehabilitation. Results All patients in the NPV-exercise group were able to tolerate and completed the program. The between-group differences were significantly better in the NPV-exercise group in changes of 6MWD (34.1 ± 12.7 m vs. -32.5 ± 17.5 m; P = 0.011) and St George Score (−14.5 ± 3.6 vs. 11.8 ± 6.0; P < 0.01). There was an improvement in dyspnea sensation (Borg’s scale, from 1.4 ± 1.5 point to 0.8 ± 1.3 point, P = 0.049) and a small increase in FVC (from 0.85 ± 0.09 L to 0.91 ± 0.08 L, P = 0.029) in the NPV-exercise group compared to the control group. Conclusion Exercise training with NPV support is feasible for patients with severe restrictive lung diseases, and improves exercise capacity and health-related quality of life. PMID:23421438

Minimal Intensity Physical Activity (Standing and Walking) of Longer Duration Improves Insulin Action and Plasma Lipids More than Shorter Periods of Moderate to Vigorous Exercise (Cycling) in Sedentary Subjects When Energy Expenditure Is Comparable

PubMed Central

Duvivier, Bernard M. F. M.; Schaper, Nicolaas C.; Bremers, Michelle A.; van Crombrugge, Glenn; Menheere, Paul P. C. A.; Kars, Marleen; Savelberg, Hans H. C. M.

2013-01-01

Background Epidemiological studies suggest that excessive sitting time is associated with increased health risk, independent of the performance of exercise. We hypothesized that a daily bout of exercise cannot compensate the negative effects of inactivity during the rest of the day on insulin sensitivity and plasma lipids. Methodology/Principal Findings Eighteen healthy subjects, age 21±2 year, BMI 22.6±2.6 kgm−2 followed randomly three physical activity regimes for four days. Participants were instructed to sit 14 hr/day (sitting regime); to sit 13 hr/day and to substitute 1 hr of sitting with vigorous exercise 1 hr (exercise regime); to substitute 6 hrs sitting with 4 hr walking and 2 hr standing (minimal intensity physical activity (PA) regime). The sitting and exercise regime had comparable numbers of sitting hours; the exercise and minimal intensity PA regime had the same daily energy expenditure. PA was assessed continuously by an activity monitor (ActivPAL) and a diary. Measurements of insulin sensitivity (oral glucose tolerance test, OGTT) and plasma lipids were performed in the fasting state, the morning after the 4 days of each regime. In the sitting regime, daily energy expenditure was about 500 kcal lower than in both other regimes. Area under the curve for insulin during OGTT was significantly lower after the minimal intensity PA regime compared to both sitting and exercise regimes 6727.3±4329.4 vs 7752.0±3014.4 and 8320.4±5383.7 mU•min/ml, respectively. Triglycerides, non-HDL cholesterol and apolipoprotein B plasma levels improved significantly in the minimal intensity PA regime compared to sitting and showed non-significant trends for improvement compared to exercise. Conclusions One hour of daily physical exercise cannot compensate the negative effects of inactivity on insulin level and plasma lipids if the rest of the day is spent sitting. Reducing inactivity by increasing the time spent walking/standing is more effective than one hour of physical exercise, when energy expenditure is kept constant. PMID:23418444

Impact of overt and subclinical hypothyroidism on exercise tolerance: a systematic review.

PubMed

Lankhaar, Jeannette A C; de Vries, Wouter R; Jansen, Jaap A C G; Zelissen, Pierre M J; Backx, Frank J G

2014-09-01

This systematic review describes the state of the art of the impact of hypothyroidism on exercise tolerance and physical performance capacity in untreated and treated patients with hypothyroidism. A systematic computer-aided search was conducted using biomedical databases. Relevant studies in English, German, and Dutch, published from the earliest date of each database up to December 2012, were identified. Out of 116 studies, a total of 38 studies with 1,379 patients fulfilled the inclusion criteria. These studies emphasize the multifactorial causes of exercise intolerance in untreated patients by the impact of limitations in different functional systems, with cardiovascular, cardiopulmonary, musculoskeletal, neuromuscular, and cellular metabolic systems acting in concert. Moreover, the studies affirm that exercise intolerance in patients is not always reversible during adequate hormone replacement therapy. As a consequence, despite a defined euthyroid status, there remains a significant group of treated patients with persistent complaints related to exercise intolerance who are suffering from limitations in daily and sport activities, as well as an impaired quality of life. An explanation for this phenomenon is lacking. Only 2 studies investigated the effects of a physical training program, and they showed inconsistent effects on the performance capacity in untreated patients with subclinical hypothyroidism. A limited body of knowledge exists concerning exercise tolerance in treated patients with hypothyroidism, and there is an insufficient amount of quantitative studies on the effects of a physical training program. To enhance exercise and sports participation for this specific group, more research in this forgotten area is warranted.

Central and peripheral effects of physical exercise without weight reduction in obese and lean mice

PubMed Central

de Carvalho, Francine Pereira; Moretto, Thaís Ludmilla; Benfato, Izabelle Dias; Barthichoto, Marcela; Ferreira, Sandra Mara; Costa-Júnior, José Maria; de Oliveira, Camila Aparecida Machado

2018-01-01

To investigate the central (hypothalamic) and peripheral effects of exercise without body weight change in diet-induced obesity (DIO). Twelve-week-old male C57Bl/6 mice received a control (C) or a high-fat diet (H). Half of them had free access to running wheels for 5 days/week for 10 weeks (CE) and HE, respectively). Hypothalamic expression of genes related to energy homeostasis, and leptin (Stat3 and p-Stat3) and insulin (Akt and p-Akt) signaling were evaluated. Glucose and leptin tolerance, peripheral insulin sensitivity, and plasma insulin, leptin and adiponectin were determined. Perigonadal and retroperitoneal fat depots were increased by diet but reduced by exercise despite lack of effect of exercise on body weight. Blood glucose during intraperitoneal glucose tolerance test (ipGTT) was higher and glucose decay during intraperitoneal insulin tolerance test (ipITT) was lower in H and HE compared with C and CE. Exercise increased liver p-Akt expression and reduced fast glycemia. High-fat diet increased plasma insulin and leptin. Exercise had no effect on insulin but decreased leptin and increased adiponectin. Leptin inhibited food intake in all groups. Hypothalamic total and p-Stat3 and Akt were similar amongst the groups despite higher plasma levels of leptin and insulin in H and HE mice. High-fat diet modulated gene expression favoring a positive energy balance. Exercise only marginally changed the gene expression. Exercise induced positive changes (decreased fast glycemia and fat depots; increased liver insulin signaling and adiponectin concentration) without weight loss. Thus, despite reducing body weight could bring additional benefits, the effects of exercise must not be overlooked when weight reduction is not achieved. PMID:29371411

Exercise Testing Reveals Everyday Physical Challenges of Bariatric Surgery Candidates.

PubMed

Creel, David B; Schuh, Leslie M; Newton, Robert L; Stote, Joseph J; Cacucci, Brenda M

2017-12-01

Few studies have quantified cardiorespiratory fitness among individuals seeking bariatric surgery. Treadmill testing allows researchers to determine exercise capacity through metabolic equivalents. These findings can assist clinicians in understanding patients' capabilities to carry out various activities of daily living. The purpose of this study was to determine exercise tolerance and the variables associated with fitness, among individuals seeking bariatric surgery. Bariatric surgery candidates completed submaximal treadmill testing and provided ratings of perceived exertion. Each participant also completed questionnaires related to history of exercise, mood, and perceived barriers/benefits of exercise. Over half of participants reported that exercise was "hard to very hard" before reaching 70% of heart rate reserve, and one-third of participants reported that exercise was "moderately hard" at less than 3 metabolic equivalents (light activity). Body mass index and age accounted for the majority of the variance in exercise tolerance, but athletic history, employment status, and perceived health benefits also contributed. Perceived benefit scores were higher than barrier scores. Categories commonly used to describe moderate-intensity exercise (3-6 metabolic equivalents) do not coincide with perceptions of intensity among many bariatric surgery candidates, especially those with a body mass index of 50 or more.

Acclimatization and tolerance to extreme altitude

NASA Technical Reports Server (NTRS)

West, J. B.

1993-01-01

During the last ten years, two major experiments have elucidated the factors determining acclimatization and tolerance to extreme altitude (over 7000 m). These were the American Medical Research Expedition to Everest, and the low pressure chamber simulation, Operation Everest II. Extreme hyperventilation is one of the most important responses to extreme altitude. Its chief value is that it allows the climber to maintain an alveolar PO2 which keeps the arterial PO2 above dangerously low levels. Even so, there is evidence of residual impairment of central nervous system function after ascents to extreme altitude, and maximal oxygen consumption falls precipitously above 7000 m. The term 'acclimatization' is probably not appropriate for altitudes above 8000 m, because the body steadily deteriorates at these altitudes. Tolerance to extreme altitude is critically dependent on barometric pressure, and even seasonal changes in pressure probably affect climbing performance near the summit of Mt Everest. Supplementary oxygen always improves exercise tolerance at extreme altitudes, and rescue oxygen should be available on climbing expeditions to 8000 m peaks.

Effects of nutraceutical diet integration, with coenzyme Q10 (Q-Ter multicomposite) and creatine, on dyspnea, exercise tolerance, and quality of life in COPD patients with chronic respiratory failure

PubMed Central

2013-01-01

Background The protein-calorie malnutrition, resulting in muscle mass loss, frequently occurs in severe COPD patients with chronic respiratory failure (CRF), causing dyspnea, reduced exercise tolerance and impaired quality of life. The cause of this occurrence is an intake-output energy imbalance. A documented deficit of phosphocreatine and reduced mithocondrial energy production can contribute to this imbalance. Aim of this study is to verify whether a dietary supplementation with creatine and coenzyme Q10, important mitochondrial function factors, is able to influence this mechanism leading to a dyspnea reduction and improving exercise tolerance and quality of life. Methods 55 COPD patients with chronic respiratory failure (in long term O2 therapy), in stable phase of the disease and without severe comorbidities were assigned (double-blind, randomized) to: group A (30 patients) with daily dietary supplementation with Creatine 340 mg + 320 mg Coenzyme Q-Ter (Eufortyn®, Scharper Therapeutics Srl) for 2 months whereas Group B (25 patients) received placebo. All patients continued the same diet, rehabilitation and therapy during the study. At recruitment (T0) and after 2 months (T1), patients were submitted to medical history, anthropometry (BMI), bioelectrical impedance, arterial blood gas analysis, evaluation of dyspnea (VAS, Borg, BDI, MRC) and functional independence (ADL), 6-minute walk test (6MWT) and quality of life questionnaire (SGRQ). At 6 months and 1 year, a telephone follow up was conducted on exacerbations number. Results No significant difference was detected at baseline (T0) in the 2 groups. After 2 months of therapy (T1) the FFMI increased in the daily dietary supplementation group (+ 3.7 %) and decreased in the placebo group (- 0.6 %), resulting in a statistically significant (p < 0.001) treatment difference. Statistically significant treatment differences, favouring daily dietary supplementation group, were also seen for the 6MWT comparison. Group A patients also showed significant: 1) improvement in the degree of dyspnea (VAS: p < 0.05; Borg: p < 0.05; MRC: p < 0.001; BDI1: p < 0.05; BDI3: p < 0.03), and independence level in activities of daily living (p < 0.03); 2) improvement in quality of life in activity section (- 6.63 pt) and in total score (- 5.43 pt); 3) exacerbation number decrease (p < 0.02). No significant differences were found (end of study vs baseline) in group B. Conclusions The nutraceutical diet integration with Q-Ter and creatine, in COPD patients with CRF in O2TLT induced an increasing lean body mass and exercise tolerance, reducing dyspnea, quality of life and exacerbations. These results provide a first demonstration that acting on protein synthesis and muscular efficiency can significantly modify the systemic consequences of the disease. PMID:23800154

Exercise Countermeasures Demonstration Project During the Lunar-Mars Life Support Test Project Phase 2A

NASA Technical Reports Server (NTRS)

Lee, Stuart M. C.; Guilliams, Mark E.; Moore, Alan D., Jr.; Williams, W. Jon; Greenisen, M. C.; Fortney, S. M.

1998-01-01

This demonstration project assessed the crew members' compliance to a portion of the exercise countermeasures planned for use onboard the International Space Station (ISS) and the outcomes of their performing these countermeasures. Although these countermeasures have been used separately in other projects and investigations, this was the first time they'd been used together for an extended period (60 days) in an investigation of this nature. Crew members exercised every day for six days, alternating every other day between aerobic and resistive exercise, and rested on the seventh day. On the aerobic exercise days, subjects exercised on an electronically braked cycle ergometer using a protocol that has been previously shown to maintain aerobic capacity in subjects exposed to a space flight analogue. On the resistive exercise days, crew members performed five major multijoint resistive exercises in a concentric mode, targeting those muscle groups and bones we believe are most severely affected by space flight. The subjects favorably tolerated both exercise protocols, with a 98% compliance to aerobic exercise prescription and a 91% adherence to the resistive exercise protocol. After 60 days, the crew members improved their peak aerobic capacity by an average 7%, and strength gains were noted in all subjects. These results suggest that these exercise protocols can be performed during ISS, lunar, and Mars missions, although we anticipate more frequent bouts with both protocols for long-duration spaceflight. Future projects should investigate the impact of increased exercise duration and frequency on subject compliance, and the efficacy of such exercise prescriptions.

Strength and Cardiorespiratory Exercise Rehabilitation for Severely Burned Patients During Intensive Care Units: A Survey of Practice.

PubMed

Cambiaso-Daniel, Janos; Parry, Ingrid; Rivas, Eric; Kemp-Offenberg, Jennifer; Sen, Soman; Rizzo, Julie A; Serghiou, Michael A; Kowalske, Karen; Wolf, Steven E; Herndon, David N; Suman, Oscar E

2018-03-22

Minimizing the deconditioning of burn injury through early rehabilitation programs (RP) in the intensive care unit (ICU) is of importance for improving the recovery time. The aim of this study was to assess current standard of care (SOC) for early ICU exercise programs in major burn centers. We designed a survey investigating exercise RP on the ICU for burn patients with >30% total burned surface area. The survey was composed of 23 questions and submitted electronically via SurveyMonkey® to six major (pediatric and adult) burn centers in Texas and California. All centers responded and reported exercise as part of their RP on the ICU. The characteristics of exercises implemented were not uniform. All centers reported to perform resistive and aerobic exercises but only 83% reported isotonic and isometric exercises. Determination of intensity of exercise varied with 50% of centers using patient tolerance and 17% using vital signs. Frequency of isotonic, isometric, aerobic, and resistive exercise was reported as daily by 80%, 80%, 83%, and 50% of centers, respectively. Duration for all types of exercises was extremely variable. Mobilization was used as a form of exercise by 100% of burn centers. Our results demonstrate that although early RP seem to be integral during burn survivor's ICU stay, no SOC exists. Moreover, early RP are inconsistently administered and large variations exist in frequency, intensity, duration, and type of exercise. Thus, future prospective studies investigating the various components of exercise interventions are needed to establish a SOC and determine how and if early exercise benefits the burn survivor.

A pilot study of biomechanical assessment before and after an integrative training program for adolescents with juvenile fibromyalgia.

PubMed

Tran, Susan T; Thomas, Staci; DiCesare, Christopher; Pfeiffer, Megan; Sil, Soumitri; Ting, Tracy V; Williams, Sara E; Myer, Gregory D; Kashikar-Zuck, Susmita

2016-07-22

Adolescents with juvenile fibromyalgia (JFM) tend to be very sedentary and avoid participation in physical activity. A prior study suggested that JFM patients show altered biomechanics compared to healthy adolescents which may make them more prone to pain/injury during exercise. A new intervention combining well established cognitive behavioral therapy (CBT) techniques with specialized neuromuscular exercise -Fibromyalgia Integrative Training for Teens (FIT Teens) was developed and shown to be promising in improving functioning in adolescents with JFM. In contrast to traditional exercise programs such as aerobic or resistance training, neuromuscular training is a tailored approach which targets gait, posture, balance and movement mechanics which form the foundation for safe exercise participation with reduced risk for injury or pain (and hence more tolerable by JFM patients). The aim of this pilot feasibility study was to establish whether objective biomechanical assessment including sophisticated 3-D motion analysis would be useful in measuring improvements in strength, balance, gait, and functional performance after participation in the 8-week FIT Teens program. Eleven female participants with JFM (ages 12-18 years) completed pre- and post-treatment assessments of biomechanics, including walking gait analysis, lower extremity strength assessment, functional performance, and dynamic postural stability. Descriptive data indicated that mechanics of walking gait and functional performance appeared to improve after treatment. Hip abduction strength and dynamic postural control also demonstrated improvements bilaterally. Overall, the results of this pilot study offer initial evidence for the utility of biomechanical assessment to objectively demonstrate observable changes in biomechanical performance after an integrated training intervention for youth with JFM. If replicated in larger controlled studies, findings would suggest that through the FIT Teens intervention, adolescents with JFM can progress towards normalized strength and biomechanics, which may enhance their ability to engage in physical exercise.

Effect of fluid ingestion on orthostatic responses following acute exercise

NASA Technical Reports Server (NTRS)

Davis, J. E.; Fortney, S. M.

1997-01-01

Orthostatic tolerance is impaired following an acute bout of exercise. This study examined the effect of fluid ingestion following treadmill exercise in restoring the cardiovascular responses to an orthostatic stress. Five men (age, 29.6 +/- 3.4 yrs) were exposed to a graded lower body negative (LBNP) pressure protocol (0 to -50 mmHg) during euhydration without exercise (C), 20 minutes after exercise dehydration (D), 20 minutes after exercise and fluid ingestion (FI20), and 60 minutes after exercise and fluid ingestion (FI60). Fluid ingestion (mean +/- SE) consisted of water-ingestion equivalent to 50% of the body weight lost during exercise (520 +/- 15 ml). Exercise dehydration resulted in significantly higher heart rates (119 +/- 8 vs 82 +/- 7 bpm), lower systolic blood pressures (95 +/- 1.7 vs 108 +/- 2.3 mmHg), a smaller increase in leg circumference (3.7 +/- 4 vs 6.9 +/- 1.0 mm), and an attenuated increase in total peripheral resistance (2.58 +/- 1.2 vs 4.28 +/- 0.9 mmHg/L/min) at -50 mmHg LBNP compared to the C condition. Fluid ingestion (both 20 and 60), partially restored the heart rate, systolic blood pressure, and total peripheral resistance responses to LBNP, but did not influence the change in leg circumference during LBNP (4 +/- 0.3 for R20 and 2.8 +/- 0.4 mm for R60). These data illustrate the effectiveness of fluid ingestion on improving orthostatic responses following exercise, and suggest that dehydration is a contributing factor to orthostatic intolerance following exercise.

Relevance of water gymnastics in rehabilitation programs in patients with chronic heart failure or coronary artery disease with normal left ventricular function.

PubMed

Teffaha, Daline; Mourot, Laurent; Vernochet, Philippe; Ounissi, Fawzi; Regnard, Jacques; Monpère, Catherine; Dugué, Benoit

2011-08-01

Exercise training is included in cardiac rehabilitation programs to enhance physical capacity and cardiovascular function. Among the existing rehabilitation programs, exercises in water are increasingly prescribed. However, it has been questioned whether exercises in water are safe and relevant in patients with stable chronic heart failure (CHF), coronary artery disease (CAD) with normal systolic left ventricular function. The goal was to assess whether a rehabilitation program, including water-based gymnastic exercises, is safe and induces at least similar benefits as a traditional land-based training. Twenty-four male CAD patients and 24 male CHF patients with stable clinical status participated in a 3-week rehabilitation. They were randomized to either a group performing the training program totally on land (CADl, CHFl; endurance + callisthenic exercises) or partly in water (CADw, CHFw; land endurance + water callisthenic exercises). Before and after rehabilitation, left ventricular systolic and cardiorespiratory functions, hemodynamic variables and autonomic nervous activities were measured. No particular complications were associated with both of our programs. At rest, significant improvements were seen in CHF patients after both types of rehabilitation (increases in stroke volume and left ventricular ejection fraction [LVEF]) as well as a decrease in heart rate (HR) and in diastolic arterial pressure. Significant increases in peaks VO(2), HR, and power output were observed in all patients after rehabilitation in exercise test. The increase in LVEF at rest, in HR and power output at the exercise peak were slightly higher in CHFw than in CHFl. Altogether, both land and water-based programs were well tolerated and triggered improvements in cardiorespiratory function. Copyright © 2011 Elsevier Inc. All rights reserved.

Influence of physical activity and gender on arterial function in type 2 diabetes, normal and impaired glucose tolerance

PubMed Central

Eriksson, Maria J.; Fritz, Tomas; Nyberg, Gunnar; Östenson, Claes Göran; Krook, Anna; Zierath, Juleen R.; Caidahl, Kenneth

2015-01-01

To determine whether Nordic walking improves cardiovascular function in middle-aged women and men, we included 121 with normal glucose tolerance, 33 with impaired glucose tolerance and 47 with Type 2 diabetes mellitus in a randomized controlled study. The intervention group added Nordic walking 5 h/week for 4 months to their ordinary activities. Aortic pulse wave velocity, aortic augmentation index, stiffness index, reflection index, intima–media thickness in the radial and carotid arteries, echogenicity of the carotid intima–media and systemic vascular resistance were measured. While baseline blood pressure did not differ by gender or diagnosis, aortic augmentation index was found to be higher in women in all groups. Vascular function was unchanged with intervention, without differences by gender or diagnosis. In conclusion, 4 months of Nordic walking is an insufficient stimulus to improve vascular function. Future studies should consider hard endpoints in addition to measures of vascular health, as well as larger population groups, long-term follow-up and documented compliance to exercise training. PMID:26092821

Improved glucose tolerance and insulin sensitivity after electrical stimulation-assisted cycling in people with spinal cord injury.

PubMed

Jeon, J Y; Weiss, C B; Steadward, R D; Ryan, E; Burnham, R S; Bell, G; Chilibeck, P; Wheeler, G D

2002-03-01

Longitudinal training. The purpose was to determine the effect of electrical stimulation (ES)-assisted cycling (30 min/day, 3 days/week for 8 weeks) on glucose tolerance and insulin sensitivity in people with spinal cord injury (SCI). The Steadward Centre, Alberta, Canada. Seven participants with motor complete SCI (five males and two females aged 30 to 53 years, injured 3-40 years, C5-T10) underwent 2-h oral glucose tolerance tests (OGTT, n=7) and hyperglycaemic clamp tests (n=3) before and after 8 weeks of training with ES-assisted cycling. Results indicated that subjects' glucose level were significantly lower at 2 h OGTT following 8 weeks of training (122.4+/-10 vs 139.9+/-16, P=0.014). Two-hour hyperglycaemic clamps tests showed improvement in all three people for glucose utilisation and in two of three people for insulin sensitivity. These results suggested that exercise with ES-assisted cycling is beneficial for the prevention and treatment of Type 2 diabetes mellitus in people with SCI. Supported by Alberta Paraplegic Foundation, Therapeutic Alliance.

[Organization and methodology of early rehabilitation of the patients with cardioembolic stroke complicated by cardiac insufficiency].

PubMed

Isaeva, T V

2013-01-01

The present work was focused on the safety and effectiveness of the combined rehabilitative treatment in the case of pre-acute and acute cardioembolic stroke in 45 patients with varying degree of cardiac decompensation. The study showed that the use of "passive" remediation, such as the postural treatment, breathing exercises, selective massage, neuromuscular electrical stimulation, is safe and can be recommended to the patients with stroke and cardiac decompensation of different severity (II and III FC of chronic cardiac insufficiency). The introduction of such active measures as verticalization into the program of comprehensive rehabilitation may cause decompensation of cardiac insufficiency. The rehabilitation strategy used in the present study improved performance and exercise tolerance in the majority of the patients. Moreover, it resulted in the significant reduction of the severity of stroke, improved the motor function, and increased functional independence of the patients.

Is rest after concussion "the best medicine?": recommendations for activity resumption following concussion in athletes, civilians, and military service members.

PubMed

Silverberg, Noah D; Iverson, Grant L

2013-01-01

Practice guidelines universally recommend an initial period of rest for people who sustain a sports-related concussion or mild traumatic brain injury (MTBI) in daily life or military service. This practice is difficult to reconcile with the compelling evidence that other health conditions can be worsened by inactivity and improved by early mobilization and exercise. We review the scientific basis for the recommendation to rest after MTBI, the challenges and potential unintended negative consequences of implementing it, and how patient management could be improved by refining it. The best available evidence suggests that complete rest exceeding 3 days is probably not helpful, gradual resumption of preinjury activities should begin as soon as tolerated (with the exception of activities that have a high MTBI exposure risk), and supervised exercise may benefit patients with persistent symptoms.

[Actions of standardized extracts of Crataegus berries on exercise tolerance and quality of life in patients with congestive heart failure].

PubMed

Rietbrock, N; Hamel, M; Hempel, B; Mitrovic, V; Schmidt, T; Wolf, G K

2001-10-01

Standardized extracts of Crataegus leaves and blossoms are said to have positive inotropic, positive dromotropic and negative bathmotropic effects. Clinical trials produce evidence for an improvement of symptoms in patients with congestive heart failure (NYHA II). In this trial the efficacy of a standardized extract of fresh Crataegus berries (Rob 10) on exercise tolerance and quality of life was studied in 88 patients. In a three-month placebo-controlled, randomized, double-blind trial these patients were treated with Rob 10 (3 x 25 drops daily). Total exercise time in bicycle ergometry was defined as primary efficacy variable, while quality of life (Minnesota Questionnaire), Dyspnea-Fatigue Index and the assessment of dyspnea by the patient on a visual analogous scale were chosen as secondary parameters. Investigations were performed after a two week placebo run-in period as well as 6 and 12 weeks after the onset of the study. Treatment with Rob 10 led to a increase of exercise time of 38.9 s vs placebo (95% confidence interval 5.7-72.1 s). Quality of life improved accordingly in favour of Rob 10. In the Minnesota Questionnaire, the total score fell by 31% (30.6 vs 44.1) under Rob 10 vs 18% (34.6 vs 42.4) under placebo. The Dyspnea-Fatigue Index demonstrated an increase of the total score of 12% (9.41 vs 8.37) vs 8% (8.92 vs 8.26) under administration of placebo. According to findings of the assessment of dyspnea by the patient, dyspnea decreased by 11% (50.5 vs 56.6 mm) vs 4% (54.8 vs 57.3 mm) under placebo. The present study proves the efficacy and safety of a standardized extract of fresh Crataegus berries (Rob 10) in patients with congestive heart failure (NYHA II) regarding the parameters evaluated.

A Qualitative Examination of a New Combined Cognitive-Behavioral and Neuromuscular Training Intervention for Juvenile Fibromyalgia.

PubMed

Kashikar-Zuck, Susmita; Tran, Susan T; Barnett, Kimberly; Bromberg, Maggie H; Strotman, Daniel; Sil, Soumitri; Thomas, Staci M; Joffe, Naomi; Ting, Tracy V; Williams, Sara E; Myer, Gregory D

2016-01-01

Adolescents with juvenile fibromyalgia (JFM) are typically sedentary despite recommendations for physical exercise, a key component of pain management. Interventions such as cognitive-behavior therapy (CBT) are beneficial but do not improve exercise participation. The objective of this study was to obtain preliminary information about the feasibility, safety, and acceptability of a new intervention--Fibromyalgia Integrative Training for Teens (FIT Teens), which combines CBT with specialized neuromuscular exercise training modified from evidence-based injury prevention protocols. Participants were 17 adolescent females (aged 12 to 18 y) with JFM. Of these, 11 completed the 8-week (16 sessions) FIT Teens program in a small-group format with 3 to 4 patients per group. Patients provided detailed qualitative feedback via individual semistructured interviews after treatment. Interview content was coded using thematic analysis. Interventionist feedback about treatment implementation was also obtained. The intervention was found to be feasible, well tolerated, and safe for JFM patients. Barriers to enrollment (50% of those approached) included difficulties with transportation or time conflicts. Treatment completers enjoyed the group format and reported increased self-efficacy, strength, and motivation to exercise. Participants also reported decreased pain and increased energy levels. Feedback from participants and interventionists was incorporated into a final treatment manual to be used in a future trial. Results of this study provided initial support for the new FIT Teens program. An integrative strategy of combining pain coping skills via CBT enhanced with tailored exercise specifically designed to improve confidence in movement and improving activity participation holds promise in the management of JFM.

A qualitative examination of a new combined cognitive-behavioral and neuromuscular training intervention for juvenile fibromyalgia

PubMed Central

Kashikar-Zuck, Susmita; Tran, Susan T.; Barnett, Kimberly; Bromberg, Maggie H.; Strotman, Daniel; Sil, Soumitri; Thomas, Staci M.; Joffe, Naomi; Ting, Tracy V.; Williams, Sara E.; Myer, Gregory D.

2015-01-01

Objectives Adolescents with juvenile fibromyalgia (JFM) are typically sedentary despite recommendations for physical exercise, a key component of pain management. Interventions such as cognitive behavioral therapy (CBT) are beneficial but do not improve exercise participation. The objective of this study was to obtain preliminary information about the feasibility, safety, and acceptability of a new intervention - Fibromyalgia Integrative Training for Teens (FIT Teens), which combines CBT with specialized neuromuscular exercise training modified from evidence-based injury prevention protocols. Methods Participants were 17 adolescent females (ages 12–18) with JFM. Of these, 11 completed the 8-week (16-session) FIT Teens program in a small-group format with 3–4 patients per group. Patients provided detailed qualitative feedback via individual semi-structured interviews after treatment. Interview content was coded using thematic analysis. Interventionist feedback about treatment implementation was also obtained. Results The intervention was found to be feasible, well-tolerated, and safe for JFM patients. Barriers to enrollment (50% of those approached) included difficulties with transportation or time conflicts. Treatment completers enjoyed the group format and reported increased self-efficacy, strength, and motivation to exercise. Participants also reported decreased pain and increased energy levels. Feedback from participants and interventionists was incorporated into a final treatment manual to be used in a future trial. Discussion Results of this study provided initial support for the new FIT Teens program. An integrative strategy of combining pain coping skills via CBT enhanced with tailored exercise specifically designed to improve confidence in movement and improving activity participation holds promise in the management of JFM. PMID:25724022

Circulating progenitor cells during exercise, muscle electro-stimulation and intermittent hypobaric hypoxia in patients with traumatic brain injury: a pilot study.

PubMed

Corral, Luisa; Conde, Laura; Guillamó, Elisabet; Blasi, Juan; Juncadella, Montserrat; Javierre, Casimiro; Viscor, Ginés; Ventura, Josep L

2014-01-01

Circulating progenitor cells (CPC) treatments may have great potential for the recovery of neurons and brain function. To increase and maintain CPC with a program of exercise, muscle electro-stimulation (ME) and/or intermittent-hypobaric-hypoxia (IHH), and also to study the possible improvement in physical or psychological functioning of participants with Traumatic Brain Injury (TBI). Twenty-one participants. Four groups: exercise and ME group (EEG), cycling group (CyG), IHH and ME group (HEG) and control group (CG). Psychological and physical stress tests were carried out. CPC were measured in blood several times during the protocol. Psychological tests did not change. In the physical stress tests the VO2 uptake increased in the EEG and the CyG, and the maximal tolerated workload increased in the HEG. CPC levels increased in the last three weeks in EEG, but not in CyG, CG and HEG. CPC levels increased in the last three weeks of the EEG program, but not in the other groups and we did not detect performed psychological test changes in any group. The detected aerobic capacity or workload improvement must be beneficial for the patients who have suffered TBI, but exercise type and the mechanisms involved are not clear.

Exercise protects against high-fat diet-induced hypothalamic inflammation.

PubMed

Yi, Chun-Xia; Al-Massadi, Omar; Donelan, Elizabeth; Lehti, Maarit; Weber, Jon; Ress, Chandler; Trivedi, Chitrang; Müller, Timo D; Woods, Stephen C; Hofmann, Susanna M

2012-06-25

Hypothalamic inflammation is a potentially important process in the pathogenesis of high-fat diet-induced metabolic disorders that has recently received significant attention. Microglia are macrophage-like cells of the central nervous system which are activated by pro-inflammatory signals causing local production of specific interleukins and cytokines, and these in turn may further promote systemic metabolic disease. Whether or how this microglial activation can be averted or reversed is unknown. Since running exercise improves systemic metabolic health and has been found to promote neuronal survival as well as the recovery of brain functions after injury, we hypothesized that regular treadmill running may blunt the effect of western diet on hypothalamic inflammation. Using low-density lipoprotein receptor deficient (l dlr-/-) mice to better reflect human lipid metabolism, we first confirmed that microglial activation in the hypothalamus is severely increased upon exposure to a high-fat, or "western", diet. Moderate, but regular, treadmill running exercise markedly decreased hypothalamic inflammation in these mice. Furthermore, the observed decline in microglial activation was associated with an improvement of glucose tolerance. Our findings support the hypothesis that hypothalamic inflammation can be reversed by exercise and suggest that interventions to avert or reverse neuronal damage may offer relevant potential in obesity treatment and prevention. Copyright © 2012 Elsevier Inc. All rights reserved.

The Influence of a Personal Values Intervention on Cold Pressor-Induced Distress Tolerance.

PubMed

Smith, Brooke M; Villatte, Jennifer L; Ong, Clarissa W; Butcher, Grayson M; Twohig, Michael P; Levin, Michael E; Hayes, Steven C

2018-06-01

Research has demonstrated that values and acceptance interventions can increase distress tolerance, but the individual contribution of each remains unclear. The current study examined the isolated effect of a values intervention on immersion time in a cold pressor. Participants randomized to Values ( n = 18) and Control ( n = 14) conditions completed two cold pressor tasks, separated by a 30-min values or control intervention. Immersion time increased 51.06 s for participants in the Values condition and decreased by 10.79 s for those in the Control condition. Increases in self-reported pain and distress predicted decreases in immersion time for Control, but not Values, participants. The best-fitting model accounted for 39% of the variance in immersion time change. Results suggest that a brief isolated values exercise can be used to improve distress tolerance despite increased perceptions of pain and distress, such that values alone may be sufficient to facilitate openness to difficult experiences.

The research and development of damage tolerant carbon fiber composites

NASA Astrophysics Data System (ADS)

Miranda, John Armando

This record of study takes a first hand look at corporate research and development efforts to improve the damage tolerance of two unique composite materials used in high performance aerospace applications. The professional internship with The Dow Chemical Company---Dow/United Technologies joint venture describes the intern's involvement in developing patentable process technologies for interleave toughening of high temperature resins and their composites. The subsequent internship with Hexcel Corporation describes the intern's involvement in developing the damage tolerance of novel and existing honeycomb sandwich structure technologies. Through the Doctor of Engineering professional internship experience this student exercised fundamental academic understanding and methods toward accomplishing the corporate objectives of the internship sponsors in a resource efficient and cost-effective manner. Also, the student gained tremendous autonomy through exceptional training in working in focused team environments with highly trained engineers and scientists in achieving important corporate objectives.

Endurance exercise intensity determination in the rehabilitation of coronary artery disease patients: a critical re-appraisal of current evidence.

PubMed

Hansen, Dominique; Stevens, An; Eijnde, Bert O; Dendale, Paul

2012-01-01

In the care of coronary artery disease (CAD) patients, the benefits of exercise therapy are generally established. Even though the selected endurance exercise intensity might affect medical safety, therapy adherence and effectiveness in the rehabilitation of CAD patients in how to determine endurance exercise intensity properly remains difficult. The aim of this review is to describe the available methods for endurance exercise intensity determination in the rehabilitation of CAD patients, accompanied with their (dis)advantages, validity and reproducibility. In general, endurance exercise intensity can objectively be determined in CAD patients by calculating a fraction of maximal exercise tolerance and/or determining ventilatory threshold after execution of a cardiopulmonary exercise test with ergospirometry. This can be translated to a corresponding training heart rate (HR) or workload. In the absence of ergospirometry equipment, target exercise HR can be calculated directly by different ways (fraction of maximal HR and/or Karvonen formula), and/or anaerobic threshold can be determined. However, the use of HR for determining exercise intensity during training sessions seems complicated, because many factors/conditions affect the HR. In this regard, proper standardization of the exercise sessions, as well as exercise testing, might be required to improve the accuracy of exercise intensity determination. Alternatively, subjective methods for the determination of endurance exercise intensity in CAD patients, such as the Borg ratings of perceived exertion and the talk test, have been developed. However, these methods lack proper validity and reliability to determine endurance exercise intensity in CAD patients. In conclusion, a practical and systematic approach for the determination of endurance exercise intensity in CAD patients is presented in this article.

Exercise Training during Normobaric Hypoxic Confinement Does Not Alter Hormonal Appetite Regulation

PubMed Central

Debevec, Tadej; Simpson, Elizabeth J.; Macdonald, Ian A.; Eiken, Ola; Mekjavic, Igor B.

2014-01-01

Background Both exposure to hypoxia and exercise training have the potential to modulate appetite and induce beneficial metabolic adaptations. The purpose of this study was to determine whether daily moderate exercise training performed during a 10-day exposure to normobaric hypoxia alters hormonal appetite regulation and augments metabolic health. Methods Fourteen healthy, male participants underwent a 10-day hypoxic confinement at ∼4000 m simulated altitude (FIO2 = 0.139±0.003%) either combined with daily moderate intensity exercise (Exercise group; N = 8, Age = 25.8±2.4 yrs, BMI = 22.9±1.2 kg·m−2) or without any exercise (Sedentary group; N = 6 Age = 24.8±3.1 yrs, BMI = 22.3±2.5 kg·m−2). A meal tolerance test was performed before (Pre) and after the confinement (Post) to quantify fasting and postprandial concentrations of selected appetite-related hormones and metabolic risk markers. 13C-Glucose was dissolved in the test meal and 13CO2 determined in breath samples. Perceived appetite ratings were obtained throughout the meal tolerance tests. Results While body mass decreased in both groups (−1.4 kg; p = 0.01) following the confinement, whole body fat mass was only reduced in the Exercise group (−1.5 kg; p = 0.01). At Post, postprandial serum insulin was reduced in the Sedentary group (−49%; p = 0.01) and postprandial plasma glucose in the Exercise group (−19%; p = 0.03). Fasting serum total cholesterol levels were reduced (−12%; p = 0.01) at Post in the Exercise group only, secondary to low-density lipoprotein cholesterol reduction (−16%; p = 0.01). No differences between groups or testing periods were noted in fasting and/or postprandial concentrations of total ghrelin, peptide YY, and glucagon-like peptide-1, leptin, adiponectin, expired 13CO2 as well as perceived appetite ratings (p>0.05). Conclusion These findings suggest that performing daily moderate intensity exercise training during continuous hypoxic exposure does not alter hormonal appetite regulation but can improve the lipid profile in healthy young males. PMID:24887106

High Intensity Interval- vs Moderate Intensity- Training for Improving Cardiometabolic Health in Overweight or Obese Males: A Randomized Controlled Trial.

PubMed

Fisher, Gordon; Brown, Andrew W; Bohan Brown, Michelle M; Alcorn, Amy; Noles, Corey; Winwood, Leah; Resuehr, Holly; George, Brandon; Jeansonne, Madeline M; Allison, David B

2015-01-01

To compare the effects of six weeks of high intensity interval training (HIIT) vs continuous moderate intensity training (MIT) for improving body composition, insulin sensitivity (SI), blood pressure, blood lipids, and cardiovascular fitness in a cohort of sedentary overweight or obese young men. We hypothesized that HIIT would result in similar improvements in body composition, cardiovascular fitness, blood lipids, and SI as compared to the MIT group, despite requiring only one hour of activity per week compared to five hours per week for the MIT group. 28 sedentary overweight or obese men (age, 20 ± 1.5 years, body mass index 29.5 ± 3.3 kg/m2) participated in a six week exercise treatment. Participants were randomly assigned to HIIT or MIT and evaluated at baseline and post-training. DXA was used to assess body composition, graded treadmill exercise test to measure cardiovascular fitness, oral glucose tolerance to measure SI, nuclear magnetic resonance spectroscopy to assess lipoprotein particles, and automatic auscultation to measure blood pressure. A greater improvement in VO2peak was observed in MIT compared to HIIT (11.1% vs 2.83%, P = 0.0185) in the complete-case analysis. No differences were seen in the intention to treat analysis, and no other group differences were observed. Both exercise conditions were associated with temporal improvements in % body fat, total cholesterol, medium VLDL, medium HDL, triglycerides, SI, and VO2peak (P < 0.05). Participation in HIIT or MIT exercise training displayed: 1) improved SI, 2) reduced blood lipids, 3) decreased % body fat, and 4) improved cardiovascular fitness. While both exercise groups led to similar improvements for most cardiometabolic risk factors assessed, MIT led to a greater improvement in overall cardiovascular fitness. Overall, these observations suggest that a relatively short duration of either HIIT or MIT training may improve cardiometabolic risk factors in previously sedentary overweight or obese young men, with no clear advantage between these two specific regimes (Clinical Trial Registry number NCT01935323). ClinicalTrials.gov NCT01935323.

High Intensity Interval- vs Moderate Intensity- Training for Improving Cardiometabolic Health in Overweight or Obese Males: A Randomized Controlled Trial

PubMed Central

Fisher, Gordon; Brown, Andrew W.; Bohan Brown, Michelle M.; Alcorn, Amy; Noles, Corey; Winwood, Leah; Resuehr, Holly; George, Brandon; Jeansonne, Madeline M.; Allison, David B.

2015-01-01

Purpose To compare the effects of six weeks of high intensity interval training (HIIT) vs continuous moderate intensity training (MIT) for improving body composition, insulin sensitivity (SI), blood pressure, blood lipids, and cardiovascular fitness in a cohort of sedentary overweight or obese young men. We hypothesized that HIIT would result in similar improvements in body composition, cardiovascular fitness, blood lipids, and SI as compared to the MIT group, despite requiring only one hour of activity per week compared to five hours per week for the MIT group. Methods 28 sedentary overweight or obese men (age, 20 ± 1.5 years, body mass index 29.5 ± 3.3 kg/m2) participated in a six week exercise treatment. Participants were randomly assigned to HIIT or MIT and evaluated at baseline and post-training. DXA was used to assess body composition, graded treadmill exercise test to measure cardiovascular fitness, oral glucose tolerance to measure SI, nuclear magnetic resonance spectroscopy to assess lipoprotein particles, and automatic auscultation to measure blood pressure. Results A greater improvement in VO2peak was observed in MIT compared to HIIT (11.1% vs 2.83%, P = 0.0185) in the complete-case analysis. No differences were seen in the intention to treat analysis, and no other group differences were observed. Both exercise conditions were associated with temporal improvements in % body fat, total cholesterol, medium VLDL, medium HDL, triglycerides, SI, and VO2peak (P < 0.05). Conclusion Participation in HIIT or MIT exercise training displayed: 1) improved SI, 2) reduced blood lipids, 3) decreased % body fat, and 4) improved cardiovascular fitness. While both exercise groups led to similar improvements for most cardiometabolic risk factors assessed, MIT led to a greater improvement in overall cardiovascular fitness. Overall, these observations suggest that a relatively short duration of either HIIT or MIT training may improve cardiometabolic risk factors in previously sedentary overweight or obese young men, with no clear advantage between these two specific regimes (Clinical Trial Registry number NCT01935323). Trial Registration ClinicalTrials.gov NCT01935323 PMID:26489022

Effects of ovariectomy and exercise training intensity on energy substrate and hepatic lipid metabolism, and spontaneous physical activity in mice.

PubMed

Tuazon, Marc A; Campbell, Sara C; Klein, Dylan J; Shapses, Sue A; Anacker, Keith R; Anthony, Tracy G; Uzumcu, Mehmet; Henderson, Gregory C

2018-06-01

Menopause is associated with fatty liver, glucose dysregulation, increased body fat, and impaired bone quality. Previously, it was demonstrated that single sessions of high-intensity interval exercise (HIIE) are more effective than distance- and duration-matched continuous exercise (CE) on altering hepatic triglyceride (TG) metabolism and very-low density lipoprotein-TG (VLDL-TG) secretion. Six weeks training using these modalities was examined for effects on hepatic TG metabolism/secretion, glucose tolerance, body composition, and bone mineral density (BMD) in ovariectomized (OVX) and sham-operated (SHAM) mice. OVX and SHAM were assigned to distance- and duration-matched CE and HIIE, or sedentary control. Energy expenditure during exercise was confirmed to be identical between CE and HIIE and both similarly reduced post-exercise absolute carbohydrate oxidation and spontaneous physical activity (SPA). OVX vs. SHAM displayed impaired glucose tolerance and greater body fat despite lower hepatic TG, and these outcomes were not affected by training. Only HIIE increased hepatic AMPK in OVX and SHAM, but neither training type impacted VLDL-TG secretion. As expected, BMD was lower in OVX, and training did not affect long bones. The results reveal intensity-dependent effects on hepatic AMPK expression and general exercise effects on subsequent SPA and substrate oxidation that is independent of estrogen status. These findings support the notion that HIIE can impact aspects of liver physiology in females while the effects of exercise on whole body substrate selection appear to be independent of training intensity. However, neither exercise approach mitigated the impairment in glucose tolerance and elevated body fat occurring in OVX mice. Copyright © 2018 Elsevier Inc. All rights reserved.

Hooked on Exercise: A Psycho-Biological Explanation.

ERIC Educational Resources Information Center

Pargman, David; Burgess, Sharon S.

A comprehensive examination of the psychological and biological factors involved in exercise addiction is presented in an attempt to explain the varying position of individuals on the continuum of ability to commence and continue a regimen of physical activity. Physiological considerations in exercise tolerance and the feelings derived from…

Vasoresponsiveness of collateral vessels in the rat hindlimb: influence of training.

PubMed

Colleran, Patrick N; Li, Zeyi; Yang, Hsiao T; Laughlin, M Harold; Terjung, Ronald L

2010-04-15

Exercise training is known to be an effective means of improving functional capacity and quality of life in patients with peripheral arterial insufficiency (PAI). However, the specific training-induced physiological adaptations occurring within collateral vessels remain to be clearly defined. The purpose of this study was to determine the effect of exercise training on vasomotor properties of isolated peripheral collateral arteries. We hypothesized that daily treadmill exercise would improve the poor vasodilatory capacity of collateral arteries isolated from rats exposed to surgical occlusion of the femoral artery. Following femoral artery ligation, animals were either kept sedentary or exercise trained daily for a period of 3 weeks. Hindlimb collateral arteries were then isolated, cannulated and pressurized via hydrostatic reservoirs to an intravascular pressure of either 45 or 120 cmH(2)O. Non-occluded contralateral vessels of the sedentary animals served as normal Control. Vasodilatory responses to acetylcholine (ACh; 1 x 10(9)-1 x 10(5)m) and sodium nitroprusside (SNP; 1 x 10(9)-1 x 10(4)m), constrictor responses to phenylephrine (PE; 1 x 10(9)-1 x 10(4)m), and flow-induced vasodilatation were determined. Endothelium-mediated vasodilatation responses were significantly greater to either ACh (P < 0.02) or intravascular flow (P < 0.001) in collateral arteries of trained rats. Neither blockade of cyclooxygenase with indomethacin (Indo; 5 microm) nor blockade of endothelial nitric oxide synthase with N(G)-nitro-L-arginine methyl ester (L-NAME; 300 microm) eliminated this ACh- or flow-induced vasodilatation. The depressed vasodilatory response to SNP caused by vascular occlusion was reversed with training. These data indicate that exercise training improves endothelium-mediated vasodilatory capacity of hindlimb collateral arteries, apparently by enhanced production of the putative endothelium-derived hyperpolarizing factor(s). If these findings were applicable to patients with PAI, they could contribute to an improved collateral vessel function and enhance exercise tolerance during routine physical activity.

Obesity impairs skeletal muscle AMPK signaling during exercise: role of AMPKα2 in the regulation of exercise capacity in vivo.

PubMed

Lee-Young, R S; Ayala, J E; Fueger, P T; Mayes, W H; Kang, L; Wasserman, D H

2011-07-01

Skeletal muscle AMP-activated protein kinase (AMPK)α2 activity is impaired in obese, insulin-resistant individuals during exercise. We determined whether this defect contributes to the metabolic dysregulation and reduced exercise capacity observed in the obese state. C57BL/6J wild-type (WT) mice and/or mice expressing a kinase dead AMPKα2 subunit in skeletal muscle (α2-KD) were fed chow or high-fat (HF) diets from 3 to 16 weeks of age. At 15 weeks, mice performed an exercise stress test to determine exercise capacity. In WT mice, muscle glucose uptake and skeletal muscle AMPKα2 activity was assessed in chronically catheterized mice (carotid artery/jugular vein) at 16 weeks. In a separate study, HF-fed WT and α2-KD mice performed 5 weeks of exercise training (from 15 to 20 weeks of age) to test whether AMPKα2 is necessary to restore work tolerance. HF-fed WT mice had reduced exercise tolerance during an exercise stress test, and an attenuation in muscle glucose uptake and AMPKα2 activity during a single bout of exercise (P<0.05 versus chow). In chow-fed α2-KD mice, running speed and time were impaired ∼45 and ∼55%, respectively (P<0.05 versus WT chow); HF feeding further reduced running time ∼25% (P<0.05 versus α2-KD chow). In response to 5 weeks of exercise training, HF-fed WT and α2-KD mice increased maximum running speed ∼35% (P<0.05 versus pre-training) and maintained body weight at pre-training levels, whereas body weight increased in untrained HF WT and α2-KD mice. Exercise training restored running speed to levels seen in healthy, chow-fed mice. HF feeding impairs AMPKα2 activity in skeletal muscle during exercise in vivo. Although this defect directly contributes to reduced exercise capacity, findings in HF-fed α2-KD mice show that AMPKα2-independent mechanisms are also involved. Importantly, α2-KD mice on a HF-fed diet adapt to regular exercise by increasing exercise tolerance, demonstrating that this adaptation is independent of skeletal muscle AMPKα2 activity.

Personalized Metabolomics for Predicting Glucose Tolerance Changes in Sedentary Women After High-Intensity Interval Training

PubMed Central

Kuehnbaum, Naomi L.; Gillen, Jenna B.; Gibala, Martin J.; Britz-McKibbin, Philip

2014-01-01

High-intensity interval training (HIIT) offers a practical approach for enhancing cardiorespiratory fitness, however its role in improving glucose regulation among sedentary yet normoglycemic women remains unclear. Herein, multi-segment injection capillary electrophoresis-mass spectrometry is used as a high-throughput platform in metabolomics to assess dynamic responses of overweight/obese women (BMI > 25, n = 11) to standardized oral glucose tolerance tests (OGTTs) performed before and after a 6-week HIIT intervention. Various statistical methods were used to classify plasma metabolic signatures associated with post-prandial glucose and/or training status when using a repeated measures/cross-over study design. Branched-chain/aromatic amino acids and other intermediates of urea cycle and carnitine metabolism decreased over time in plasma after oral glucose loading. Adaptive exercise-induced changes to plasma thiol redox and orthinine status were measured for trained subjects while at rest in a fasting state. A multi-linear regression model was developed to predict changes in glucose tolerance based on a panel of plasma metabolites measured for naïve subjects in their untrained state. Since treatment outcomes to physical activity are variable between-subjects, prognostic markers offer a novel approach to screen for potential negative responders while designing lifestyle modifications that maximize the salutary benefits of exercise for diabetes prevention on an individual level. PMID:25164777

Increased fibre and reduced trans fatty acid intake are primary predictors of metabolic improvement in overweight polycystic ovary syndrome-Substudy of randomized trial between diet, exercise and diet plus exercise for weight control.

PubMed

Nybacka, Åsa; Hellström, Per M; Hirschberg, Angelica L

2017-12-01

Polycystic ovary syndrome (PCOS) is commonly affected by obesity. PCOS phenotypes are prone to increased waist/hip ratio, insulin resistance and dyslipidaemia. This substudy was undertaken to evaluate the effects of lifestyle interventions on metabolic biomarkers in overweight/obese PCOS women and the interventional effects of dietary components related to metabolic outcomes. Randomized three-arm parallel study. Fifty-seven PCOS women body mass index (BMI >27 kg/m 2 , age 18-40) were randomly assigned to diet (D, n = 19), exercise (E, n = 19) or diet plus exercise (DE, n = 19) in three-arm fashion over 16 weeks. The D group received nutritional counselling by a dietician to reduce their energy intake by at least 600 kcal/d. The E group received an ambulatory exercise regimen from a physiotherapist. The DE group had both interventions. Self-reported food intake over 4 days, exercise pedometers, BMI, waist/hip ratio, blood pressure, body composition and oral glucose tolerance test were performed before and at the end of intervention. BMI, waist circumference and total cholesterol were significantly reduced in the D and DE groups, as well as low-density lipoprotein and Homeostasis Model of Assessment index in the D group. In the E group, exercise was increased along with a decrease in BMI and waist circumference. The strongest predictor of reduced BMI was increased fibre intake (-0.44, P = .03), while a decrease in trans fatty acid intake predicted reduced insulinogenic index (0.44, P < .01). Nutritional counselling with dieting is clearly effective to improve metabolic disturbances in overweight/obese women with PCOS. Increased fibre and reduced trans fatty acid intake are primary predictors of metabolic improvement and weight control. © 2017 John Wiley & Sons Ltd.

Endurance training and detraining in mitochondrial myopathies due to single large-scale mtDNA deletions.

PubMed

Taivassalo, Tanja; Gardner, Julie L; Taylor, Robert W; Schaefer, Andrew M; Newman, Jane; Barron, Martin J; Haller, Ronald G; Turnbull, Douglass M

2006-12-01

At present there are limited therapeutic interventions for patients with mitochondrial myopathies. Exercise training has been suggested as an approach to improve physical capacity and quality of life but it is uncertain whether it offers a safe and effective treatment for patients with heteroplasmic mitochondrial DNA (mtDNA) mutations. The objectives of this study were to assess the effects of exercise training and detraining in eight patients with single, large-scale mtDNA deletions to determine: (i) the efficacy and safety of endurance training (14 weeks) in this patient population; (ii) to determine the effect of more prolonged (total of 28 weeks) exercise training upon muscle and cardiovascular function and (iii) to evaluate the effect of discontinued training (14 weeks) upon muscle and cardiovascular function. Our results show that: (i) 14 weeks of exercise training significantly improved tolerance of submaximal exercise and peak capacity for work, oxygen utilization and skeletal muscle oxygen extraction with no change in the level of deleted mtDNA; (ii) continued training for an additional 14 weeks maintained these beneficial adaptations; (iii) the cessation of training (detraining) resulted in loss of physiological adaptation to baseline capacity with no overall change in mutation load. Patients' self assessment of quality of life as measured by the SF-36 questionnaire improved with training and declined with detraining. Whilst our findings of beneficial effects of training on physiological outcome and quality of life without increases in the percentage of deleted mtDNA are encouraging, we did not observe changes in mtDNA copy number. Therefore there remains a need for longer term studies to confirm that endurance exercise is a safe and effective treatment for patients with mitochondrial myopathies. The effects of detraining clearly implicate physical inactivity as an important mechanism in reducing exercise capacity and quality of life in patients with mitochondrial myopathy.

Strength Exercise Improves Muscle Mass and Hepatic Insulin Sensitivity in Obese Youth

PubMed Central

van der Heijden, Gert-Jan; Wang, Zhiyue J.; Chu, Zili; Toffolo, Gianna; Manesso, Erica; Sauer, Pieter J.J.; Sunehag, Agneta L.

2010-01-01

Introduction Data are limited on the metabolic effects of resistance exercise (strength training) in adolescents. Purpose The objective of this study was to determine whether a controlled resistance exercise program without dietary intervention or weight loss, reduces body fat accumulation, increases lean body mass, and improves insulin sensitivity and glucose metabolism in sedentary obese Hispanic adolescents. Methods Twelve obese adolescents (15.5±0.5y; 35.3 ±0.8kg/m2;40.8±1.5% body fat), completed a 12 wk resistance exercise program (2×1h/wk, exercising all major muscle groups). At baseline and completion of the program, body composition was measured by DXA, abdominal fat distribution by Magnetic Resonance Imaging, hepatic and intramyocellular fat by Magnetic Resonance Spectroscopy, peripheral insulin sensitivity by the Stable Labeled IV Glucose Tolerance Test and hepatic insulin sensitivity by the Hepatic Insulin Sensitivity Index =1000/(GPR*fasting insulin). Glucose production rate (GPR), gluconeogenesis and glycogenolysis were quantified using Stable Isotope-Gas Chromatography/Mass Spectrometry techniques. Results All participants were normoglycemic. The exercise program resulted in significant strength gain in both upper and lower body muscle groups. Body weight increased from 97.0±3.8 to 99.6±4.2 kg (p<0.01). The major part (~80%) was accounted for by increased lean body mass (55.7±2.8 to 57.9±3.0 kg; p≤0.01).Total, visceral, hepatic and intramyocellular fat content remained unchanged. Hepatic insulin sensitivity increased by 24±9% (p<0.05), while peripheral insulin sensitivity did not change significantly. GPR decreased by 8±1% (p<0.01) due to a 12±5% decrease in glycogenolysis (p<0.05). Conclusion We conclude that a controlled resistance exercise program without weight loss increases strength and lean body mass, improves hepatic insulin sensitivity and decreases GPR without affecting total fat mass or visceral, hepatic and intramyocellular fat content. PMID:20351587

Lung function profiles and aerobic capacity of adult cigarette and hookah smokers after 12 weeks intermittent training.

PubMed

Koubaa, Abdessalem; Triki, Moez; Trabelsi, Hajer; Masmoudi, Liwa; Zeghal, Khaled N; Sahnoun, Zouhair; Hakim, Ahmed

2015-01-01

Introduction Pulmonary function is compromised in most smokers. Yet it is unknown whether exercise training improves pulmonary function and aerobic capacity in cigarette and hookah smokers and whether these smokers respond in a similar way as do non-smokers. Aim To evaluate the effects of an interval exercise training program on pulmonary function and aerobic capacity in cigarette and hookah smokers. Methods Twelve cigarette smokers, 10 hookah smokers, and 11 non-smokers participated in our exercise program. All subjects performed 30 min of interval exercise (2 min of work followed by 1 min of rest) three times a week for 12 weeks at an intensity estimated at 70% of the subject's maximum aerobic capacity ([Formula: see text]). Pulmonary function was measured using spirometry, and maximum aerobic capacity was assessed by maximal exercise testing on a treadmill before the beginning and at the end of the exercise training program. Results As expected, prior to the exercise intervention, the cigarette and hookah smokers had significantly lower pulmonary function than the non-smokers. The 12-week exercise training program did not significantly affect lung function as assessed by spirometry in the non-smoker group. However, it significantly increased both forced expiratory volume in 1 second and peak expiratory flow (PEF) in the cigarette smoker group, and PEF in the hookah smoker group. Our training program had its most notable impact on the cardiopulmonary system of smokers. In the non-smoker and cigarette smoker groups, the training program significantly improved [Formula: see text] (4.4 and 4.7%, respectively), v [Formula: see text] (6.7 and 5.6%, respectively), and the recovery index (7.9 and 10.5%, respectively). Conclusions After 12 weeks of interval training program, the increase of [Formula: see text] and the decrease of recovery index and resting heart rate in the smoking subjects indicated better exercise tolerance. Although the intermittent training program altered pulmonary function only partially, both aerobic capacity and life quality were improved. Intermittent training should be advised in the clinical setting for subjects with adverse health behaviors.

Lung function profiles and aerobic capacity of adult cigarette and hookah smokers after 12 weeks intermittent training.

PubMed

Koubaa, Abdessalem; Triki, Moez; Trabelsi, Hajer; Masmoudi, Liwa; Zeghal, Khaled N; Sahnoun, Zouhair; Hakim, Ahmed

2015-01-01

Pulmonary function is compromised in most smokers. Yet it is unknown whether exercise training improves pulmonary function and aerobic capacity in cigarette and hookah smokers and whether these smokers respond in a similar way as do non-smokers. To evaluate the effects of an interval exercise training program on pulmonary function and aerobic capacity in cigarette and hookah smokers. Twelve cigarette smokers, 10 hookah smokers, and 11 non-smokers participated in our exercise program. All subjects performed 30 min of interval exercise (2 min of work followed by 1 min of rest) three times a week for 12 weeks at an intensity estimated at 70% of the subject's maximum aerobic capacity (VO2max). Pulmonary function was measured using spirometry, and maximum aerobic capacity was assessed by maximal exercise testing on a treadmill before the beginning and at the end of the exercise training program. As expected, prior to the exercise intervention, the cigarette and hookah smokers had significantly lower pulmonary function than the non-smokers. The 12-week exercise training program did not significantly affect lung function as assessed by spirometry in the non-smoker group. However, it significantly increased both forced expiratory volume in 1 second and peak expiratory flow (PEF) in the cigarette smoker group, and PEF in the hookah smoker group. Our training program had its most notable impact on the cardiopulmonary system of smokers. In the non-smoker and cigarette smoker groups, the training program significantly improved VO2max (4.4 and 4.7%, respectively), v VO2max (6.7 and 5.6%, respectively), and the recovery index (7.9 and 10.5%, respectively). After 12 weeks of interval training program, the increase of VO2max and the decrease of recovery index and resting heart rate in the smoking subjects indicated better exercise tolerance. Although the intermittent training program altered pulmonary function only partially, both aerobic capacity and life quality were improved. Intermittent training should be advised in the clinical setting for subjects with adverse health behaviors.

High Intensity Interval Training Improves Physical Performance and Frailty in Aged Mice.

PubMed

Seldeen, Kenneth Ladd; Lasky, Ginger; Leiker, Merced Marie; Pang, Manhui; Personius, Kirkwood Ely; Troen, Bruce Robert

2018-03-14

Sarcopenia and frailty are highly prevalent in older individuals, increasing the risk of disability and loss of independence. High intensity interval training (HIIT) may provide a robust intervention for both sarcopenia and frailty by achieving both strength and endurance benefits with lower time commitments than other exercise regimens. To better understand the impacts of HIIT during aging, we compared 24-month-old C57BL/6J sedentary mice with those that were administered 10-minute uphill treadmill HIIT sessions three times per week over 16 weeks. Baseline and end point assessments included body composition, physical performance, and frailty based on criteria from the Fried physical frailty scale. HIIT-trained mice demonstrated dramatic improvement in grip strength (HIIT 10.9% vs -3.9% in sedentary mice), treadmill endurance (32.6% vs -2.0%), and gait speed (107.0% vs 39.0%). Muscles from HIIT mice also exhibited greater mass, larger fiber size, and an increase in mitochondrial biomass. Furthermore, HIIT exercise led to a dramatic reduction in frailty scores in five of six mice that were frail or prefrail at baseline, with four ultimately becoming nonfrail. The uphill treadmill HIIT exercise sessions were well tolerated by aged mice and led to performance gains, improvement in underlying muscle physiology, and reduction in frailty.

Cost-saving effect of supervised exercise associated to COPD self-management education program.

PubMed

Ninot, G; Moullec, G; Picot, M C; Jaussent, A; Hayot, M; Desplan, M; Brun, J F; Mercier, J; Prefaut, C

2011-03-01

Although the benefits of comprehensive pulmonary rehabilitation have been demonstrated in patients with COPD, the effects of exercise sessions within self-management programs remain unclear. We hypothesized that 8 supervised exercise sessions incorporated in a 1-month self-management education program in COPD patients would be effective to improve health outcomes and to reduce direct medical costs after one year, compared to usual care. In this randomized controlled trial, 38 moderate-to-severe COPD patients were assigned either to an intervention group or to a usual care group. The hospital-based intervention program provided a combination of 8 sessions of supervised exercise with 8 self-management education sessions over a 1-month period. The primary end-point was the 6-min walking distance (6MWD), with secondary outcomes being health-related quality of life (HRQoL)--using the St. George's Respiratory Questionnaire (SGRQ) and Nottingham Health Profile (NHP), maximal exercise capacity and healthcare utilization. Data were collected before and one year after the program. After 12 months, we found statistically significant between-group differences in favor of the intervention group in 6MWD (+50.5 m (95%CI, 2 to 99), in two domains of NHP (energy, -19.8 (-38 to -1); emotional reaction, -10.4 (-20 to 0)); in SGRQ-symptoms (-14.0 (-23 to -5)), and in cost of COPD medication (-480.7 € (CI, -891 to -70) per patient per year). The present hospital-based intervention combining supervised exercise with self-management education provides significant improvements in patient's exercise tolerance and HRQoL, and significant decrease of COPD medication costs, compared to usual care. Copyright © 2010 Elsevier Ltd. All rights reserved.

Electromyography-controlled exoskeletal upper-limb-powered orthosis for exercise training after stroke.

PubMed

Stein, Joel; Narendran, Kailas; McBean, John; Krebs, Kathryn; Hughes, Richard

2007-04-01

Robot-assisted exercise shows promise as a means of providing exercise therapy for weakness that results from stroke or other neurological conditions. Exoskeletal or "wearable" robots can, in principle, provide therapeutic exercise and/or function as powered orthoses to help compensate for chronic weakness. We describe a novel electromyography (EMG)-controlled exoskeletal robotic brace for the elbow (the active joint brace) and the results of a pilot study conducted using this brace for exercise training in individuals with chronic hemiparesis after stroke. Eight stroke survivors with severe chronic hemiparesis were enrolled in this pilot study. One subject withdrew from the study because of scheduling conflicts. A second subject was unable to participate in the training protocol because of insufficient surface EMG activity to control the active joint brace. The six remaining subjects each underwent 18 hrs of exercise training using the device for a period of 6 wks. Outcome measures included the upper-extremity component of the Fugl-Meyer scale and the modified Ashworth scale of muscle hypertonicity. Analysis revealed that the mean upper-extremity component of the Fugl-Meyer scale increased from 15.5 (SD 3.88) to 19 (SD 3.95) (P = 0.04) at the conclusion of training for the six subjects who completed training. Combined (summated) modified Ashworth scale for the elbow flexors and extensors improved from 4.67 (+/-1.2 SD) to 2.33 (+/-0.653 SD) (P = 0.009) and improved for the entire upper limb as well. All subjects tolerated the device, and no complications occurred. EMG-controlled powered elbow orthoses can be successfully controlled by severely impaired hemiparetic stroke survivors. This technique shows promise as a new modality for assisted exercise training after stroke.

Aerobic exercise improves cognition for older adults with glucose intolerance, a risk factor for Alzheimer's disease.

PubMed

Baker, Laura D; Frank, Laura L; Foster-Schubert, Karen; Green, Pattie S; Wilkinson, Charles W; McTiernan, Anne; Cholerton, Brenna A; Plymate, Stephen R; Fishel, Mark A; Watson, G Stennis; Duncan, Glen E; Mehta, Pankaj D; Craft, Suzanne

2010-01-01

Impaired glucose regulation is a defining characteristic of type 2 diabetes mellitus (T2DM) pathology and has been linked to increased risk of cognitive impairment and dementia. Although the benefits of aerobic exercise for physical health are well-documented, exercise effects on cognition have not been examined for older adults with poor glucose regulation associated with prediabetes and early T2DM. Using a randomized controlled design, twenty-eight adults (57-83 y old) meeting 2-h tolerance test criteria for glucose intolerance completed 6 months of aerobic exercise or stretching, which served as the control. The primary cognitive outcomes included measures of executive function (Trails B, Task Switching, Stroop, Self-ordered Pointing Test, and Verbal Fluency). Other outcomes included memory performance (Story Recall, List Learning), measures of cardiorespiratory fitness obtained via maximal-graded exercise treadmill test, glucose disposal during hyperinsulinemic-euglycemic clamp, body fat, and fasting plasma levels of insulin, cortisol, brain-derived neurotrophic factor, insulin-like growth factor-1, amyloid-β (Aβ40 and Aβ42). Six months of aerobic exercise improved executive function (MANCOVA, p=0.04), cardiorespiratory fitness (MANOVA, p=0.03), and insulin sensitivity (p=0.05). Across all subjects, 6-month changes in cardiorespiratory fitness and insulin sensitivity were positively correlated (p=0.01). For Aβ42, plasma levels tended to decrease for the aerobic group relative to controls (p=0.07). The results of our study using rigorous controlled methodology suggest a cognition-enhancing effect of aerobic exercise for older glucose intolerant adults. Although replication in a larger sample is needed, our findings potentially have important therapeutic implications for a growing number of adults at increased risk of cognitive decline.

Dietary thiols in exercise: oxidative stress defence, exercise performance, and adaptation.

PubMed

McLeay, Yanita; Stannard, Stephen; Houltham, Stuart; Starck, Carlene

2017-01-01

Endurance athletes are susceptible to cellular damage initiated by excessive levels of aerobic exercise-produced reactive oxygen species (ROS). Whilst ROS can contribute to the onset of fatigue, there is increasing evidence that they play a crucial role in exercise adaptations. The use of antioxidant supplements such as vitamin C and E in athletes is common; however, their ability to enhance performance and facilitate recovery is controversial, with many studies suggesting a blunting of training adaptations with supplementation. The up-regulation of endogenous antioxidant systems brought about by exercise training allows for greater tolerance to subsequent ROS, thus, athletes may benefit from increasing these systems through dietary thiol donors. Recent work has shown supplementation with a cysteine donor (N-acetylcysteine; NAC) improves antioxidant capacity by augmenting glutathione levels and reducing markers of oxidative stress, as well as ergogenic potential through association with delayed fatigue in numerous experimental models. However, the use of this, and other thiol donors may have adverse physiological effects. A recent discovery for the use of a thiol donor food source, keratin, to potentially enhance endogenous antioxidants may have important implications for endurance athletes hoping to enhance performance and recovery without blunting training adaptations.

Exercise Training and Calorie Restriction Influence the Metabolic Parameters in Ovariectomized Female Rats

PubMed Central

Pósa, Anikó; Kupai, Krisztina; Szalai, Zita; Veszelka, Médea; Török, Szilvia; Varga, Csaba

2015-01-01

The estrogen deficiency after menopause leads to overweight or obesity, and physical exercise is one of the important modulators of this body weight gain. Female Wistar rats underwent ovariectomy surgery (OVX) or sham operation (SO). OVX and SO groups were randomized into new groups based on the voluntary physical activity (with or without running) and the type of diet for 12 weeks. Rats were fed standard chow (CTRL), high triglyceride diet (HT), or restricted diet (CR). The metabolic syndrome was assessed by measuring the body weight gain, the glucose sensitivity, and the levels of insulin, triglyceride, leptin, and aspartate aminotransferase transaminase (AST) and alanine aminotransferase (ALT). The exercise training combined with the CR resulted in improvements in the glucose tolerance and the insulin sensitivity. Plasma TG, AST, and ALT levels were significantly higher in OVX rats fed with HT but these high values were suppressed by exercise and CR. Compared to SO animals, estrogen deprivation with HT caused a significant increase in leptin level. Our data provide evidence that CR combined with voluntary physical exercise can be a very effective strategy to prevent the development of a metabolic syndrome induced by high calorie diet. PMID:25874022

Potential neurobiological benefits of exercise in chronic pain and posttraumatic stress disorder: Pilot study.

PubMed

Scioli-Salter, Erica; Forman, Daniel E; Otis, John D; Tun, Carlos; Allsup, Kelly; Marx, Christine E; Hauger, Richard L; Shipherd, Jillian C; Higgins, Diana; Tyzik, Anna; Rasmusson, Ann M

2016-01-01

This pilot study assessed the effects of cardiopulmonary exercise testing and cardiorespiratory fitness on plasma neuropeptide Y (NPY), allopregnanolone and pregnanolone (ALLO), cortisol, and dehydroepiandrosterone (DHEA), and their association with pain sensitivity. Medication-free trauma-exposed participants were either healthy (n = 7) or experiencing comorbid chronic pain/posttraumatic stress disorder (PTSD) (n = 5). Peak oxygen consumption (VO2) during exercise testing was used to characterize cardiorespiratory fitness. Peak VO2 correlated with baseline and peak NPY levels (r = 0.66, p < 0.05 and r = 0.69, p < 0.05, respectively), as well as exercise-induced changes in ALLO (r = 0.89, p < 0.001) and peak ALLO levels (r = 0.71, p < 0.01). NPY levels at the peak of exercise correlated with pain threshold 30 min after exercise (r = 0.65, p < 0.05), while exercise-induced increases in ALLO correlated with pain tolerance 30 min after exercise (r = 0.64, p < 0.05). In contrast, exercise-induced changes in cortisol and DHEA levels were inversely correlated with pain tolerance after exercise (r = -0.69, p < 0.05 and r = -0.58, p < 0.05, respectively). These data suggest that cardiorespiratory fitness is associated with higher plasma NPY levels and increased ALLO responses to exercise, which in turn relate to pain sensitivity. Future work will examine whether progressive exercise training increases cardiorespiratory fitness in association with increases in NPY and ALLO and reductions in pain sensitivity in chronic pain patients with PTSD.

Prophylactic effects of swimming exercise on autophagy-induced muscle atrophy in diabetic rats

PubMed Central

Lee, Youngjeon; Kim, Joo-Heon; Hong, Yunkyung; Lee, Sang-Rae; Chang, Kyu-Tae

2012-01-01

Diabetes decreases skeletal muscle mass and induces atrophy. However, the mechanisms by which hyperglycemia and insulin deficiency modify muscle mass are not well defined. In this study, we evaluated the effects of swimming exercise on muscle mass and intracellular protein degradation in diabetic rats, and proposed that autophagy inhibition induced by swimming exercise serves as a hypercatabolic mechanism in the skeletal muscles of diabetic rats, supporting a notion that swimming exercise could efficiently reverse the reduced skeletal muscle mass caused by diabetes. Adult male Sprague-Dawley rats were injected intraperitoneally with streptozotocin (60 mg/kg body weight) to induce diabetes and then submitted to 1 hr per day of forced swimming exercise, 5 days per week for 4 weeks. We conducted an intraperitoneal glucose tolerance test on the animals and measured body weight, skeletal muscle mass, and protein degradation and examined the level of autophagy in the isolated extensor digitorum longus, plantaris, and soleus muscles. Body weight and muscle tissue mass were higher in the exercising diabetic rats than in control diabetic rats that remained sedentary. Compared to control rats, exercising diabetic rats had lower blood glucose levels, increased intracellular contractile protein expression, and decreased autophagic protein expression. We conclude that swimming exercise improves muscle mass in diabetes-induced skeletal muscle atrophy, suggesting the activation of autophagy in diabetes contributes to muscle atrophy through hypercatabolic metabolism and that aerobic exercise, by suppressing autophagy, may modify or reverse skeletal muscle wasting in diabetic patients. PMID:23091517

PULMONARY CIRCULATION AT EXERCISE

PubMed Central

NAEIJE, R; CHESLER, N

2012-01-01

The pulmonary circulation is a high flow and low pressure circuit, with an average resistance of 1 mmHg.min.L−1 in young adults, increasing to 2.5 mmHg.min.L−1 over 4–6 decades of life. Pulmonary vascular mechanics at exercise are best described by distensible models. Exercise does not appear to affect the time constant of the pulmonary circulation or the longitudinal distribution of resistances. Very high flows are associated with high capillary pressures, up to a 20–25 mmHg threshold associated with interstitial lung edema and altered ventilation/perfusion relationships. Pulmonary artery pressures of 40–50 mmHg, which can be achieved at maximal exercise, may correspond to the extreme of tolerable right ventricular afterload. Distension of capillaries that decrease resistance may be of adaptative value during exercise, but this is limited by hypoxemia from altered diffusion/perfusion relationships. Exercise in hypoxia is associated with higher pulmonary vascular pressures and lower maximal cardiac output, with increased likelihood of right ventricular function limitation and altered gas exchange by interstitial lung edema. Pharmacological interventions aimed at the reduction of pulmonary vascular tone have little effect on pulmonary vascular pressure-flow relationships in normoxia, but may decrease resistance in hypoxia, unloading the right ventricle and thereby improving exercise capacity. Exercise in patients with pulmonary hypertension is associated with sharp increases in pulmonary artery pressure and a right ventricular limitation of aerobic capacity. Exercise stress testing to determine multipoint pulmonary vascular pressures-flow relationships may uncover early stage pulmonary vascular disease. PMID:23105961

A study on nonlinear estimation of submaximal effort tolerance based on the generalized MET concept and the 6MWT in pulmonary rehabilitation

PubMed Central

Szczegielniak, Jan; Łuniewski, Jacek; Stanisławski, Rafał; Bogacz, Katarzyna; Krajczy, Marcin; Rydel, Marek

2018-01-01

Background The six-minute walk test (6MWT) is considered to be a simple and inexpensive tool for the assessment of functional tolerance of submaximal effort. The aim of this work was 1) to background the nonlinear nature of the energy expenditure process due to physical activity, 2) to compare the results/scores of the submaximal treadmill exercise test and those of 6MWT in pulmonary patients and 3) to develop nonlinear mathematical models relating the two. Methods The study group included patients with the COPD. All patients were subjected to a submaximal exercise test and a 6MWT. To develop an optimal mathematical solution and compare the results of the exercise test and the 6MWT, the least squares and genetic algorithms were employed to estimate parameters of polynomial expansion and piecewise linear models. Results Mathematical analysis enabled to construct nonlinear models for estimating the MET result of submaximal exercise test based on average walk velocity (or distance) in the 6MWT. Conclusions Submaximal effort tolerance in COPD patients can be effectively estimated from new, rehabilitation-oriented, nonlinear models based on the generalized MET concept and the 6MWT. PMID:29425213

Effects of a supervised, outpatient exercise and physiotherapy programme in children with cystic fibrosis.

PubMed

Urquhart, Donald; Sell, Zoe; Dhouieb, Elaine; Bell, Gillian; Oliver, Sarah; Black, Ryan; Tallis, Matthew

2012-12-01

Previous work suggests benefit from outpatient exercise and physiotherapy in children with cystic fibrosis (CF), namely improved exercise capacity and lung function measures, as well reduced intravenous (IV) antibiotic needs. Our study aim was to investigate the effect of a year-long supervised outpatient exercise and physiotherapy programme in children with CF. Subjects with CF aged ≥10 years who had received ≥4 courses of IV antibiotics in 2009 were enrolled and seen fortnightly for supervised exercise and physiotherapy throughout 2010. In addition, they were expected to exercise three times weekly, and if unwell complete additional physiotherapy sessions extra to usual chest physiotherapy. Assessments of exercise capacity using the Modified Shuttle Test (MST) and quality of life (QOL; CFQ-UK) were recorded at baseline and after 1 year. Regular spirometry was performed before and throughout the study. Data were collected on IV antibiotic days. 12 subjects (6 female) were enrolled with mean (95% CI) age of 13.3 (11.8-14.6) years at study entry. A significant reduction in IV antibiotic days from 60 (56-64) days in 2009 to 50 (44-56) in 2010 (P = 0.02) was noted, along with improved MST distance (m) [735 (603-867) vs. 943 (725-1,161), P = 0.04] and level attained [9.4 (8.4-10.5) vs. 11.1 (9.6-12.6), P = 0.04]. Significant improvements in CFQ-UK scores for physical [59 (47-72) vs. 83 (74-92), P = 0.001], emotional [63 (55-72) vs. 84 (74-93), P < 0.001], treatment [41 (30-51) vs. 61 (48-73), P = 0.002], and respiratory [54 (42-66) vs. 76 (70-82), P = 0.002] domains were noted. The mean (95% CI) rate of change of FEV(1) was -4 (-18, +10)% in 2009, but was +6 (-2, +13)% in 2010, although this did not reach statistical significance. Supervised, outpatient exercise and physiotherapy are associated with improvements in QOL and exercise tolerance, a reduction in IV antibiotic days, and a trend towards reducing lung function decline in children with CF. The cost of IV antibiotics was reduced by £66,384 ($104,000) in 2010 when compared with 2009. Such cost-benefit may have implications for workforce planning and service provision. Copyright © 2012 Wiley Periodicals, Inc.

The European Association of Preventive Cardiology Exercise Prescription in Everyday Practice and Rehabilitative Training (EXPERT) tool: A digital training and decision support system for optimized exercise prescription in cardiovascular disease. Concept, definitions and construction methodology.

PubMed

Hansen, Dominique; Dendale, Paul; Coninx, Karin; Vanhees, Luc; Piepoli, Massimo F; Niebauer, Josef; Cornelissen, Veronique; Pedretti, Roberto; Geurts, Eva; Ruiz, Gustavo R; Corrà, Ugo; Schmid, Jean-Paul; Greco, Eugenio; Davos, Constantinos H; Edelmann, Frank; Abreu, Ana; Rauch, Bernhard; Ambrosetti, Marco; Braga, Simona S; Barna, Olga; Beckers, Paul; Bussotti, Maurizio; Fagard, Robert; Faggiano, Pompilio; Garcia-Porrero, Esteban; Kouidi, Evangelia; Lamotte, Michel; Neunhäuserer, Daniel; Reibis, Rona; Spruit, Martijn A; Stettler, Christoph; Takken, Tim; Tonoli, Cajsa; Vigorito, Carlo; Völler, Heinz; Doherty, Patrick

2017-07-01

Background Exercise rehabilitation is highly recommended by current guidelines on prevention of cardiovascular disease, but its implementation is still poor. Many clinicians experience difficulties in prescribing exercise in the presence of different concomitant cardiovascular diseases and risk factors within the same patient. It was aimed to develop a digital training and decision support system for exercise prescription in cardiovascular disease patients in clinical practice: the European Association of Preventive Cardiology Exercise Prescription in Everyday Practice and Rehabilitative Training (EXPERT) tool. Methods EXPERT working group members were requested to define (a) diagnostic criteria for specific cardiovascular diseases, cardiovascular disease risk factors, and other chronic non-cardiovascular conditions, (b) primary goals of exercise intervention, (c) disease-specific prescription of exercise training (intensity, frequency, volume, type, session and programme duration), and (d) exercise training safety advices. The impact of exercise tolerance, common cardiovascular medications and adverse events during exercise testing were further taken into account for optimized exercise prescription. Results Exercise training recommendations and safety advices were formulated for 10 cardiovascular diseases, five cardiovascular disease risk factors (type 1 and 2 diabetes, obesity, hypertension, hypercholesterolaemia), and three common chronic non-cardiovascular conditions (lung and renal failure and sarcopaenia), but also accounted for baseline exercise tolerance, common cardiovascular medications and occurrence of adverse events during exercise testing. An algorithm, supported by an interactive tool, was constructed based on these data. This training and decision support system automatically provides an exercise prescription according to the variables provided. Conclusion This digital training and decision support system may contribute in overcoming barriers in exercise implementation in common cardiovascular diseases.

Aerobic training suppresses exercise-induced lipid peroxidation and inflammation in overweight/obese adolescent girls.

PubMed

Youssef, Hala; Groussard, Carole; Lemoine-Morel, Sophie; Pincemail, Joel; Jacob, Christophe; Moussa, Elie; Fazah, Abdallah; Cillard, Josiane; Pineau, Jean-Claude; Delamarche, Arlette

2015-02-01

This study aimed to determine whether aerobic training could reduce lipid peroxidation and inflammation at rest and after maximal exhaustive exercise in overweight/obese adolescent girls. Thirty-nine adolescent girls (14-19 years old) were classified as nonobese or overweight/obese and then randomly assigned to either the nontrained or trained group (12-week multivariate aerobic training program). Measurements at the beginning of the experiment and at 3 months consisted of body composition, aerobic fitness (VO2peak) and the following blood assays: pre- and postexercise lipid peroxidation (15F2a-isoprostanes [F2-Isop], lipid hydroperoxide [ROOH], oxidized LDL [ox-LDL]) and inflammation (myeloperoxidase [MPO]) markers. In the overweight/ obese group, the training program significantly increased their fat-free mass (FFM) and decreased their percentage of fat mass (%FM) and hip circumference but did not modify their VO2peak. Conversely, in the nontrained overweight/obese group, weight and %FM increased, and VO2peak decreased, during the same period. Training also prevented exercise-induced lipid peroxidation and/or inflammation in overweight/obese girls (F2-Isop, ROOH, ox-LDL, MPO). In addition, in the trained overweight/obese group, exercise-induced changes in ROOH, ox-LDL and F2-Isop were correlated with improvements in anthropometric parameters (waist-to-hip ratio, %FM and FFM). In conclusion aerobic training increased tolerance to exercise-induced oxidative stress in overweight/obese adolescent girls partly as a result of improved body composition.

Acute effects of physical exercise in type 2 diabetes: A review

PubMed Central

Asano, Ricardo Yukio; Sales, Marcelo Magalhães; Browne, Rodrigo Alberto Vieira; Moraes, José Fernando Vila Nova; Coelho Júnior, Hélio José; Moraes, Milton Rocha; Simões, Herbert Gustavo

2014-01-01

The literature has shown the efficiency of exercise in the control of type 2 diabetes (T2D), being suggested as one of the best kinds of non-pharmacological treatments for its population. Thus, the scientific production related to this phenomenon has growing exponentially. However, despite its advances, still there is a lack of studies that have carried out a review on the acute effects of physical exercise on metabolic and hemodynamic markers and possible control mechanisms of these indicators in individuals with T2D, not to mention that in a related way, these themes have been very little studied today. Therefore, the aim of this study was to organize and analyze the current scientific production about the acute effects of physical exercise on metabolic and hemodynamic markers and possible control mechanisms of these indicators in T2D individuals. For such, a research with the following keywords was performed: -exercise; diabetes and post-exercise hypotension; diabetes and excess post-exercise oxygen consumption; diabetes and acute effects in PUBMED, SCIELO and HIGHWIRE databases. From the analyzed studies, it is possible to conclude that, a single exercise session can promote an increase in the bioavailability of nitric oxide and elicit decreases in postexercise blood pressure. Furthermore, the metabolic stress from physical exercise can increase the oxidation of carbohydrate during the exercise and keep it, in high levels, the post exercise consumption of O², this phenomenon increases the rate of fat oxidation during recovery periods after exercise, improves glucose tolerance and insulin sensitivity and reduces glycemia between 2-72 h, which seems to be dependent on the exercise intensity and duration of the effort. PMID:25317243

Influence of muscle pain tolerance on muscle pain threshold in experimental tooth clenching in man.

PubMed

Christensen, L V

1979-07-01

Ten adults and ten children exercised maximal voluntary tooth clenching until pains appeared in the jaw muscles, i.e. the muscle pain threshold of tooth clenching was determined. Subsequently, the subjects were instructed to exercise tooth clenching until they were forced to stop because of intolerable pains and exhaustion of the contracting muscles, i.e. the muscle pain tolerance of tooth clenching was recorded, and during these bouts of clenching the pain tolerance of tooth clenching was recorded, and during these bouts of clenching the pain threshold was also determined. In adults, determination of the pain tolerance decreased the pain threshold by 19%, and in children it either decreased the pain threshold by 20% or increased it by 56%. It is proposed to introduce the muscle pain tolerance of tooth clenching as an adjunct in the clinical examination of cases of facial pains presumed to originate from the jaw muscles, but the test should be interpreted with caution.

Effect of Resistance Exercises on the Indicators of Muscle Reserves and Handgrip Strength in Adult Patients on Hemodialysis.

PubMed

Olvera-Soto, Ma Guadalupe; Valdez-Ortiz, Rafael; López Alvarenga, Juan Carlos; Espinosa-Cuevas, María de Los Ángeles

2016-01-01

Although resistance exercise has been associated with improvement in the muscle reserves, muscle strength and quality of life in end-stage renal disease patients, the objective of this paper is to evaluate the effect of resistance exercise performed during hemodialysis sessions on the anthropometric indicators of muscle reserve and handgrip strength in sedentary malnourished patients with end-stage renal disease. Patients were randomized to perform resistance exercise during hemodialysis sessions with ankle weights and resistance bands. The exercises were performed twice a week over the course of 12 weeks. The control group underwent a hemodialysis session alone. The outcomes measures were the following anthropometric measurements: arm muscle circumference and arm muscle area. Dynamometry was used to measure the handgrip strength. Sixty-one sedentary patients with a median age of 29 years (interquartile range [IQR] 21-39 years), and 83% presenting with some grade of malnutrition were equally randomized to either the intervention or control group. In the resistance exercise group, there was an increase in the arm muscle circumference from 233.6 (IQR 202-254) mm to 241.4 (IQR 203-264) mm (P= .001), arm muscle area from 35.9 (26-41) cm(2) to 36.6 (IQR 26-46) cm(2) (P= .002), and handgrip strength from 19.6 (IQR 11-28) kg to 21.2 (IQR 13-32) kg between the basal and final measurements (P < .05). The tolerance to exercise was adequate, and no adverse events were reported during the practical exercise. Resistance exercise at least twice a week is safe and represents an opportunity for improving the muscle mass and strength in adult patients who are on hemodialysis, including in those with malnutrition. Copyright © 2016 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

Fluid restriction during exercise in the heat reduces tolerance to progressive central hypovolaemia.

PubMed

Schlader, Zachary J; Gagnon, Daniel; Rivas, Eric; Convertino, Victor A; Crandall, Craig G

2015-08-01

What is the central question of this study? Interactions between dehydration, as occurs during exercise in the heat without fluid replacement, and hyperthermia on the ability to tolerate central hypovolaemia are unknown. What is the main finding and its importance? We show that inadequate fluid intake during exercise in the heat can impair tolerance to central hypovolaemia even when it elicits only mild dehydration. These findings suggest that hydration during physical work in the heat has important military and occupational relevance for protection against the adverse effects of a subsequent haemorrhagic injury. This study tested the hypothesis that dehydration induced via exercise in the heat impairs tolerance to central hypovolaemia. Eleven male subjects (32 ± 7 years old, 81.5 ± 11.1 kg) walked (O2 uptake 1.7 ± 0.4 l min(-1) ) in a 40°C, 30% relative humidity environment on three occasions, as follows: (i) subjects walked for 90 min, drinking water to offset sweat loss (Hydrated, n = 11); (ii) water intake was restricted, and exercise was terminated when intestinal temperature increased to the same level as in the Hydrated trial (Isothermic Dehydrated, n = 11); and (iii) water intake was restricted, and exercise duration was 90 min (Time Match Dehydrated, n = 9). For each trial, tolerance to central hypovolaemia was determined following exercise via progressive lower body negative pressure and quantified as time to presyncope. Increases in intestinal temperature prior to lower body negative pressure were not different (P = 0.91) between Hydrated (1.1 ± 0.4°C) and Isothermic Dehydrated trials (1.1 ± 0.4°C), but both were lower than in the Time Match Dehydrated trial (1.7 ± 0.5°C, P < 0.01). Prior to lower body negative pressure, body weight was unchanged in the Hydrated trial (-0.1 ± 0.2%), but was reduced in Isothermic Dehydrated (-0.9 ± 0.4%) and further so in Time Match Dehydrated trial (-1.9 ± 0.6%, all P < 0.01). Time to presyncope was greater in Hydrated (14.7 ± 3.2 min) compared with Isothermic Dehydrated (11.9 ± 3.3 min, P < 0.01) and Time Match Dehydrated trials (10.2 ± 1.6 min, P = 0.03), which were not different (P = 0.19). These data indicate that inadequate fluid intake during exercise in the heat reduces tolerance to central hypovolaemia independent of increases in body temperature. © 2015 The Authors. Experimental Physiology © 2015 The Physiological Society.

The Effects of a Motorized Aquatic Treadmill Exercise Program on Muscle Strength, Cardiorespiratory Fitness, and clinical function in Subacute Stroke Patients -- a Randomized Controlled Pilot Trial.

PubMed

Lee, So Young; Han, Eun Young; Kim, Bo Ryun; Im, Sang Hee

2018-03-12

The aim of this study was to assess the effects of a motorized aquatic treadmill exercise program improve the isometric strength of the knee muscles, cardiorespiratory fitness, arterial stiffness, motor function, balance, functional outcomes and quality of life in subacute stroke patients. Thirty-two patients were randomly assigned to 4-week training sessions of either aquatic therapy(n=19) or land-based aerobic exercise(n=18). Isometric strength was measured using an isokinetic dynamometer. Cardiopulmonary fitness was evaluated using a symptom-limited exercise tolerance test and by measuring brachial ankle pulse wave velocity. Moreover, motor function(Fugl-Meyer Assessment[FMA] and FMA-lower limb[FMA-LL]), balance(Berg Balance Scale[BBS]), Activities of daily living(Korean version of the Modified Barthel Index [K-MBI]), and Quality of life(EQ-5D index) were examined. There were no inter-group differences between demographic and clinical characteristics at baseline(p>0.05). The results shows significant improvements in peak oxygen consumption (p=0.02), maximal isometric strength of the bilateral knee extensors (p<0.01) and paretic knee flexors (p=0.01), FMA (p=0.03), FMA-LL (p=0.01), BBS (p=0.01), K-MBI (p<0.01), and EQ-5D index (p=0.04) after treatment in the aquatic therapy group. However, only significant improvements in maximal isometric strength in the knee extensors (p=0.03) and flexors (p=0.04) were found within the aquatic therapy group and control group. Water-based aerobic exercise performed on a motorized aquatic treadmill had beneficial effect on isometric muscle strength in the lower limb.

Improved exercise capacity and reduced systemic inflammation after adenoviral-mediated SERCA-2a gene transfer.

PubMed

Gupta, Dipin; Palma, Jon; Molina, Ezequiel; Gaughan, John P; Long, Walter; Houser, Steven; Macha, Mahender

2008-04-01

We hypothesized that sarcoplasmic reticulum Ca2+ ATPase pump (SERCA-2a) gene delivery would have beneficial effects upon exercise capacity and markers of inflammation in the setting of heart failure. A pressure-overload model of experimental heart failure was used in rats. Following a decrease in fractional shortening of >or=25%, animals underwent intracoronary adenoviral-mediated gene transfection using SERCA-2a. Heart failure animals were randomized to receive the SERCA-2a gene, the beta galactosidase (control) gene, or followed without any further intervention. Exercise and hemodynamic testing were performed, and myocardial and systemic markers of inflammation were assayed after 7 and 21 d. Animals receiving Ad.SERCA-2a showed an increase in exercise tolerance (499.0 +/- 14.9 versus 312.8 +/- 10.5 s, P < 0.0001) relative to Ad.Gal group. Groups treated with Ad.SERCA-2a had significantly decreased serum levels of the inflammatory markers interleukin-1, interleukin-6, and tumor necrosis factor-alpha compared with Ad.Gal-treated animals. Serum levels of atrial natriuretic peptide were decreased in animals receiving Ad.SERCA-2a compared with animals receiving Ad.Gal at day 7 (0.35 +/- 0.03 versus 0.52 +/- 0.11 pg/mL, P = 0.001). Myocardial levels of the proapoptotic protein bax were reduced in Ad.SERCA-2a -treated animals compared with those receiving Ad.Gal at day 7 (protein level/actin: 0.24 +/- 0.05 versus 0.33 +/- 0.04, P = 0.04) and day 21 (protein level/actin: 0.61 +/- 0.04 versus 0.69 +/- 0.01, P = 0.001). Genetic modulation of heart failure using the SERCA-2a gene was associated with improvement in cardiac function and exercise capacity as well as improvements in heart-failure associated inflammatory markers.

Respiratory muscle training improves respiratory muscle endurance but not exercise tolerance in children with cystic fibrosis.

PubMed

Bieli, Christian; Summermatter, Selina; Boutellier, Urs; Moeller, Alexander

2017-03-01

Respiratory muscle endurance (RME) training has been shown to increase exercise endurance and lung function in adults with cystic fibrosis (CF). We conducted an interventional study to investigate the effectiveness of RME training on CF-related health outcomes in children. In a crossover trial, 22 children, aged 9-18 years, with CF performed 8 weeks of RME training and standard chest physiotherapy in a randomized sequence separated by a 1 week washout period. All children underwent training sessions using the RME training device before beginning the study. The primary outcomes were RME (in minutes) and exercise endurance (in minutes). Data were analyzed according to the intention-to-treat principle. Sixteen of 22 children (73%) completed the study. Study dropouts tended to be older with more advanced lung disease. After RME training, respiratory muscle endurance significantly increased by 7.03 ± 8.15 min (mean ± standard deviation, P < 0.001), whereas exercise endurance was unchanged by RME training (0.80 ± 2.58 min, P = 0.169). No significant improvement in secondary outcomes (lung function, CF quality of life, and CF clinical score) were observed. The small sample size and short intervention time have to be acknowledged as limitations of our study. RME training led to a significant increase in respiratory muscle endurance in children with CF. However, RME training did not improve exercise endurance or other CF-related health outcomes. Thus, our results do not support the routine use of RME training in the care of children with CF. Future studies in larger populations and with prolonged intervention time may overcome the limitations of our study. Pediatr Pulmonol. 2017;52:331-336. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Maximal Oxygen Uptake, Sweating and Tolerance to Exercise in the Heat

NASA Technical Reports Server (NTRS)

Greenleaf, J. E.; Castle, B. L.; Ruff, W. K.

1972-01-01

The physiological mechanisms that facilitate acute acclimation to heat have not been fully elucidated, but the result is the establishment of a more efficient cardiovascular system to increase heat dissipation via increased sweating that allows the acclimated man to function with a cooler internal environment and to extend his performance. Men in good physical condition with high maximal oxygen uptakes generally acclimate to heat more rapidly and retain it longer than men in poorer condition. Also, upon first exposure trained men tolerate exercise in the heat better than untrained men. Both resting in heat and physical training in a cool environment confer only partial acclimation when first exposed to work in the heat. These observations suggest separate additive stimuli of metabolic heat from exercise and environmental heat to increase sweating during the acclimation process. However, the necessity of utilizing physical exercise during acclimation has been questioned. Bradbury et al. (1964) have concluded exercise has no effect on the course of heat acclimation since increased sweating can be induced by merely heating resting subjects. Preliminary evidence suggests there is a direct relationship between the maximal oxygen uptake and the capacity to maintain thermal regulation, particularly through the control of sweating. Since increased sweating is an important mechanism for the development of heat acclimation, and fit men have high sweat rates, it follows that upon initial exposure to exercise in the heat, men with high maximal oxygen uptakes should exhibit less strain than men with lower maximal oxygen uptakes. The purpose of this study was: (1) to determine if men with higher maximal oxygen uptakes exhibit greater tolerance than men with lower oxygen uptakes during early exposure to exercise in the heat, and (2) to investigate further the mechanism of the relationship between sweating and maximal work capacity.

Effects of exercise-heat acclimation on fluid, electrolyte, and endocrine responses during tilt and +Gz acceleration in women and men

NASA Technical Reports Server (NTRS)

Greenleaf, J. E.; Brock, P. J.; Sciaraffa, D.; Polese, A.; Elizondo, R.

1985-01-01

Two aspects of prolonged endurance training were investigated: (1) the effects of exercise-heat acclimation (on a cycle ergometer at 40 C, 42 rh) on orthostatic tolerance (70 deg head-up tilt) and on a +Gz (head-to-foot) acceleration tolerance of male and female subjects; and (2) comparison of their fluid-electrolyte shifts and hormonal (plasma epinephdrine, norepinephrine, renin, and vasopressin) responses during tilting and centrifugation. The adaptive responses during the 12 d, 2-h acclimation did not alter acceleration tolerance of either men or women, or the women's tilt tolerance, but did increase men's tilt tolerance from 30.4 min before to 58.3 min after acclimation. The patterns of fluid, electrolyte, and protein shifts at tolerance in acceleration and tilting tests were virtually the same in men and women. On the other hand, the hormonal plasma epinephrine, norepinephrine, renin, and vasopressin resonses displayed different shift patterns during acceleration and tilting. It is concluded that the responses to tilting cannot be used to predict responses to acceleration. Future experiments for relating the orthostatic and the acceleration tolerances, and the practical questions of the training regimens for future astronauts are discussed.

Physical activity and pregnancy: cardiovascular adaptations, recommendations and pregnancy outcomes.

PubMed

Melzer, Katarina; Schutz, Yves; Boulvain, Michel; Kayser, Bengt

2010-06-01

Regular physical activity is associated with improved physiological, metabolic and psychological parameters, and with reduced risk of morbidity and mortality. Current recommendations aimed at improving the health and well-being of nonpregnant subjects advise that an accumulation of > or =30 minutes of moderate physical activity should occur on most, if not all, days of the week. Regardless of the specific physiological changes induced by pregnancy, which are primarily developed to meet the increased metabolic demands of mother and fetus, pregnant women benefit from regular physical activity the same way as nonpregnant subjects. Changes in submaximal oxygen uptake (VO(2)) during pregnancy depend on the type of exercise performed. During maternal rest or submaximal weight-bearing exercise (e.g. walking, stepping, treadmill exercise), absolute maternal VO(2) is significantly increased compared with the nonpregnant state. The magnitude of change is approximately proportional to maternal weight gain. When pregnant women perform submaximal weight-supported exercise on land (e.g. level cycling), the findings are contradictory. Some studies reported significantly increased absolute VO(2), while many others reported unchanged or only slightly increased absolute VO(2) compared with the nonpregnant state. The latter findings may be explained by the fact that the metabolic demand of cycle exercise is largely independent of the maternal body mass, resulting in no absolute VO(2) alteration. Few studies that directly measured changes in maternal maximal VO(2) (VO(2max)) showed no difference in the absolute VO(2max) between pregnant and nonpregnant subjects in cycling, swimming or weight-bearing exercise. Efficiency of work during exercise appears to be unchanged during pregnancy in non-weight-bearing exercise. During weight-bearing exercise, the work efficiency was shown to be improved in athletic women who continue exercising and those who stop exercising during pregnancy. When adjusted for weight gain, the increased efficiency is maintained throughout the pregnancy, with the improvement being greater in exercising women. Regular physical activity has been proven to result in marked benefits for mother and fetus. Maternal benefits include improved cardiovascular function, limited pregnancy weight gain, decreased musculoskeletal discomfort, reduced incidence of muscle cramps and lower limb oedema, mood stability, attenuation of gestational diabetes mellitus and gestational hypertension. Fetal benefits include decreased fat mass, improved stress tolerance, and advanced neurobehavioural maturation. In addition, few studies that have directly examined the effects of physical activity on labour and delivery indicate that, for women with normal pregnancies, physical activity is accompanied with shorter labour and decreased incidence of operative delivery. However, a substantial proportion of women stop exercising after they discover they are pregnant, and only few begin participating in exercise activities during pregnancy. The adoption or continuation of a sedentary lifestyle during pregnancy may contribute to the development of certain disorders such as hypertension, maternal and childhood obesity, gestational diabetes, dyspnoea, and pre-eclampsia. In view of the global epidemic of sedentary behaviour and obesity-related pathology, prenatal physical activity was shown to be useful for the prevention and treatment of these conditions. Further studies with larger sample sizes are required to confirm the association between physical activity and outcomes of labour and delivery.

Effect of Fontan geometry on exercise haemodynamics and its potential implications.

PubMed

Tang, Elaine; Wei, Zhenglun Alan; Whitehead, Kevin K; Khiabani, Reza H; Restrepo, Maria; Mirabella, Lucia; Bethel, James; Paridon, Stephen M; Marino, Bradley S; Fogel, Mark A; Yoganathan, Ajit P

2017-11-01

Exercise intolerance afflicts Fontan patients with total cavopulmonary connections (TCPCs) causing a reduction in quality of life. Optimising TCPC design is hypothesised to have a beneficial effect on exercise capacity. This study investigates relationships between TCPC geometries and exercise haemodynamics and performance. This study included 47 patients who completed metabolic exercise stress test with cardiac magnetic resonance (CMR). Phase-contrast CMR images were acquired immediately following supine lower limb exercise. Both anatomies and exercise vessel flow rates at ventilatory anaerobic threshold (VAT) were extracted. The vascular modelling toolkits were used to analyse TCPC geometries. Computational simulations were performed to quantify TCPC indexed power loss (iPL) at VAT. A highly significant inverse correlation was found between the TCPC diameter index, which factors in the narrowing of TCPC vessels, with iPL at VAT (r=-0.723, p<0.001) but positive correlations with exercise performance variables, including minute oxygen consumption (VO 2 ) at VAT (r=0.373, p=0.01), VO 2 at peak exercise (r=0.485, p=0.001) and work at VAT/weight (r=0.368, p=0.01). iPL at VAT was negatively correlated with VO 2 at VAT (r=-0.337, p=0.02), VO 2 at peak exercise (r=-0.394, p=0.007) and work at VAT/weight (r=-0.208, p=0.17). Eliminating vessel narrowing in TCPCs and reducing elevated iPL at VAT could enhance exercise tolerance for patients with TCPCs. These findings could help plan surgical or catheter-based strategies to improve patients' exercise capacity. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Repeated bouts of exhaustive exercise increase circulating cell free nuclear and mitochondrial DNA without development of tolerance in healthy men

PubMed Central

Stawski, Robert; Walczak, Konrad; Kosielski, Piotr; Meissner, Pawel; Budlewski, Tomasz; Padula, Gianluca; Nowak, Dariusz

2017-01-01

Objective Acute single strenuous exercise increases circulating cell free DNA (cf DNA). We tested whether three repeated bouts of exhaustive exercise induced the cf DNA response without development of tolerance in healthy men. Methods Eleven average-trained men (age 34.0±5.2 years, body mass index 26.2±3.1 kg/m2, maximal oxygen consumption—VO2max 49.6±4.5 ml/kg*min) performed three treadmill exercise tests to exhaustion at speed corresponding to 70% VO2max separated by 72 hours of resting. Blood was collected before and after each bout of exercise for determination of cell free nuclear and mitochondrial DNA (cf n-DNA, cf mt-DNA) by real-time PCR, selected markers of muscle damage, and blood cell count. Results Each bout induced the increase (p<0.05) in plasma cf n-DNA: from 3.4±1.4 to 38.5±27.5, from 4.1±3.3 to 48.5±26.2, and 3.1±1.6 to 53.8±39.9 ng/mL after the first, second, and third exercise, respectively. In a congruent way, cf mt-DNA rose significantly after the second (from 229±216 to 450±228*103 GE/mL) and third bout of exercise (from 173±120 to 462±314*103 GE/mL). Pre-exercise cf mt-DNA decreased (p<0.05) by 2-times (from 355±219 before the first bout to 173±120*103 GE/mL before the third bout) over the study period and were accompanied by significant increase in white blood cells, platelets, creatine kinase, creatinine and lactate after each bout. However, the exercise induced percentage increment of cf n-DNA was always many times higher than corresponding increments of the afore-mentioned markers at any occasion. Conclusions Repeated bouts of exhaustive exercise induced remarkable increase in circulating cf n-DNA without signs of tolerance development. Baseline cf mt-DNA decreased in response to series of strenuous exercise. Since percentage increments of cf n-DNA in response to exercise were many times higher than those observed for other markers, measurement of circulating cf n-DNA could be a sensitive tool for monitoring acute exercise effects in human body. PMID:28542490

Combining Short-Term Interval Training with Caloric Restriction Improves ß-Cell Function in Obese Adults.

PubMed

Francois, Monique E; Gilbertson, Nicole M; Eichner, Natalie Z M; Heiston, Emily M; Fabris, Chiara; Breton, Marc; Mehaffey, J Hunter; Hassinger, Taryn; Hallowell, Peter T; Malin, Steven K

2018-06-03

Although low-calorie diets (LCD) improve glucose regulation, it is unclear if interval exercise (INT) is additive. We examined the impact of an LCD versus LCD + INT training on ß-cell function in relation to glucose tolerance in obese adults. Twenty-six adults (Age: 46 ± 12 year; BMI 38 ± 6 kg/m²) were randomized to 2-week of LCD (~1200 kcal/day) or energy-matched LCD + INT (60 min/day alternating 3 min at 90 and 50% HRpeak). A 2 h 75 g oral glucose tolerance test (OGTT) was performed. Insulin secretion rates (ISR) were determined by deconvolution modeling to assess glucose-stimulated insulin secretion ([GSIS: ISR/glucose total area under the curve (tAUC)]) and ß-cell function (Disposition Index [DI: GSIS/IR]) relative to skeletal muscle (Matsuda Index), hepatic (HOMA-IR) and adipose (Adipose-IR fasting ) insulin resistance (IR). LCD + INT, but not LCD alone, reduced glucose and total-phase ISR tAUC (Interactions: p = 0.04 and p = 0.05, respectively). Both interventions improved skeletal muscle IR by 16% ( p = 0.04) and skeletal muscle and hepatic DI (Time: p < 0.05). Improved skeletal muscle DI was associated with lower glucose tAUC ( r = -0.57, p < 0.01). Thus, LCD + INT improved glucose tolerance more than LCD in obese adults, and these findings relate to ß-cell function. These data support LCD + INT for preserving pancreatic function for type 2 diabetes prevention.

Exercise-induced changes in cardiovascular function after stroke: a randomized controlled trial

PubMed Central

Tang, Ada; Krassioukov, Andrei V; Madden, Kenneth M; Mohammadi, Azam; Tsang, Michael YC; Tsang, Teresa SM

2015-01-01

Background and aims Cardiovascular co-morbidities are prevalent after stroke, with heart disease, hypertension and impaired glucose tolerance present in the majority of cases. Exercise has the potential to mediate cardiovascular risk factors commonly present in people with stroke. This single-blinded randomized controlled trial compared the effects of high versus low intensity exercise on fitness, cardiovascular risk factors, and cardiac function after stroke. Methods Fifty participants (age 50–80y, >1y post-stroke) were randomized to a high-intensity Aerobic Exercise (AE) or low-intensity non-aerobic Balance/Flexibility (BF) program (6 months, 3 60-minute sessions/week). Outcomes assessed by VO2peak (primary outcome), arterial stiffness, ambulatory capacity, hemodynamics and cardiac function using echocardiography, and lipid, glucose and homocysteine levels. Assessors were blinded to group allocation. Results Twenty-three (92%) of 25 AE group participants (withdrawals unrelated to the intervention) and all BF group participants completed the program. One BF group participant experienced 2 non-injurious falls during class. No other adverse events occurred. There were no changes in VO2peak in either group (AE 16.9±7 to 17.4±7 ml•kg−1•min−1 vs. BF 16.9±6 to 16.6±5 ml•kg−1•min−1, P=0.45), but AE group demonstrated greater improvement in right atrial emptying fraction (AE 30±22 to 37±22% vs. BF 35±20 to 31±20%, P=0.04). Both groups demonstrated improvements in lipid profiles, glucose and homocysteine levels, and ambulatory capacity (P<0.04). Conclusions This was the first study to examine the effects of aerobic exercise after stroke on cardiovascular hemodynamics. High-intensity exercise improved right-sided function and early myocardial relaxation. Low-intensity exercise may also benefit plasma lipid, glucose and inflammatory markers, and ambulatory capacity. This study is an important step towards understanding mechanisms by which exercise may reduce cardiovascular risk and function. Clinical Trial Registration Information http://www.clinicaltrials.gov. Unique identifier: NCT01189045 PMID:24148695

Effects of prehabilitation and rehabilitation including a home-based component on physical fitness, adherence, treatment tolerance, and recovery in patients with non-small cell lung cancer: A systematic review.

PubMed

Driessen, Elisabeth J; Peeters, Marieke E; Bongers, Bart C; Maas, Huub A; Bootsma, Gerbern P; van Meeteren, Nico L; Janssen-Heijnen, Maryska L

2017-06-01

This systematic review aimed to examine physical fitness, adherence, treatment tolerance, and recovery for (p)rehabilitation including a home-based component for patients with non-small cell lung cancer (NSCLC). PRISMA and Cochrane guidelines were followed. Studies describing (home-based) prehabilitation or rehabilitation in patients with NSCLC were included from four databases (January 2000-April 2016, N=11). Nine of ten rehabilitation studies and one prehabilitation study (437 NSCLC patients, mean age 59-72 years) showed significantly or clinically relevant improved physical fitness. Three (27%) assessed home-based training and eight (73%) combined training at home, inhospital (intramural) and/or at the physiotherapy practice/department (extramural). Six (55%) applied supervision of home-based components, and four (36%) a personalized training program. Adherence varied strongly (9-125% for exercises, 50-100% for patients). Treatment tolerance and recovery were heterogeneously reported. Although promising results of (p)rehabilitation for improving physical fitness were found (especially in case of supervision and personalization), adequately powered studies for home-based (p)rehabilitation are needed. Copyright © 2017 Elsevier B.V. All rights reserved.

Medium-/long-term effects of a specific exercise protocol combined with patient education on spine mobility, chronic fatigue, pain, aerobic fitness and level of disability in fibromyalgia.

PubMed

Giannotti, Erika; Koutsikos, Konstantinos; Pigatto, Maurizia; Rampudda, Maria Elisa; Doria, Andrea; Masiero, Stefano

2014-01-01

To propose a rehabilitation protocol able to produce immediate and long-term beneficial effects on level of disability and overall performance in ADLs. Forty-one FM patients were randomized to an exercise and educational-behavioral programme group (experimental group, EG = 21) or to a control group (CG = 20). Each subject was evaluated before, at the end (T1), and after 6 months (T6) from the conclusion of the rehabilitation treatment using the Fibromyalgia Impact Questionnaire (FIQ), the visual analogue scale (VAS), the Health Assessment Questionnaire (HAQ), the fatigue severity scale (FSS), the 6-minute walking test (6MWT), tender points count (TPC), and spinal active range of motion. The exercise protocol included 20 sessions consisting in self-awareness, stretching, strengthening, spine flexibility, and aerobic exercises, which patients were subsequently educated to perform at home. The two groups were comparable at baseline. At T1, the EG showed a positive trend in FIQ, VAS, HAQ, and FSS scales and significant improvement in 6MWT and in most spinal active range of motion measurements (P between 0.001 and 0.04). The positive results were maintained at the follow-up. The proposed programme was well tolerated and produced immediate and medium-term beneficial effects improving function and strain endurance. This trial is registered with DRKS00005071 on DRKS.

Beneficial effects of exercise on offspring obesity and insulin resistance are reduced by maternal high-fat diet

PubMed Central

Schreiber, Saskia; Klaus, Susanne; Kanzleiter, Isabel

2017-01-01

Scope We investigated the long-term effects of maternal high-fat consumption and post-weaning exercise on offspring obesity susceptibility and insulin resistance. Methods C57BL/6J dams were fed either a high-fat (HFD, 40% kcal fat) or low-fat (LFD, 10% kcal fat) semi-synthetic diet during pregnancy and lactation. After weaning, male offspring of both maternal diet groups (mLFD; mHFD) received a LFD. At week 7, half of the mice got access to a running wheel (+RW) as voluntary exercise training. To induce obesity, all offspring groups (mLFD +/-RW and mHFD +/-RW) received HFD from week 15 until week 25. Results Compared to mLFD, mHFD offspring were more prone to HFD-induced body fat gain and exhibited an increased liver mass which was not due to increased hepatic triglyceride levels. RW improved the endurance capacity in mLFD, but not in mHFD offspring. Additionally, mHFD offspring +RW exhibited higher plasma insulin levels during glucose tolerance test and an elevated basal pancreatic insulin production compared to mLFD offspring. Conclusion Taken together, maternal HFD reduced offspring responsiveness to the beneficial effects of voluntary exercise training regarding the improvement of endurance capacity, reduction of fat mass gain, and amelioration of HFD-induced insulin resistance. PMID:28235071

Balance exercise in patients with chronic sensory ataxic neuropathy: a pilot study.

PubMed

Riva, Nilo; Faccendini, Simone; Lopez, Ignazio D; Fratelli, Annamaria; Velardo, Daniele; Quattrini, Angelo; Gatti, Roberto; Comi, Giancarlo; Comola, Mauro; Fazio, Raffaella

2014-06-01

Although exercise therapy is considered part of the treatment of neuropathic patients, and somatosensory input is essential for motor learning, performance and neural plasticity, rehabilitation of patients with sensory ataxia has received little attention so far. The aim of this prospective pilot study was to explore the short- and medium-term efficacy of a 3-week intensive balance and treadmill exercise program in chronic ataxic neuropathy patients; 20 consecutive patients with leg overall disability sum score (ODSS-leg) ≥2, absent/mild motor signs, clinical and therapeutic stability ≥4 months were enrolled. Evaluations were done at baseline, at the end of treatment and at 3- and 6-month follow-up. Outcome measurements included: ODSS-leg, Berg balance scale, 6-min walk distance, and the functional independence measure (FIM) scale. The short-form-36 health status scale (SF-36) was used to measure health-related quality of life (HRQoL). ODSS-leg improved significantly compared with baseline, 3 weeks, 3 months (primary outcome), and 6 months follow-up. A significant improvement in all functional secondary outcome measurements and in some SF-36 subscales was also observed. This pilot study suggests that balance exercise is safe and well tolerated and might be effective in ameliorating disability and HRQoL in patients with chronic peripheral sensory ataxia. © 2014 Peripheral Nerve Society.

Hot Topics in Primary Care: Management of Opioid-induced Constipation.

PubMed

Johnson, David A; Argoff, Charles E

2015-12-01

Constipation is a common complication of opioid therapy that contributes to substantial patient morbidity, decreased productivity, and opioid nonadherence. Other causes of constipation may occur concomitantly and should be investigated. Although evidence supporting their use is limited, the use of fiber, water, laxatives, and/or exercise is recommended in current guidelines as initial management. Peripherally acting μ-opioid receptor antagonists are important treatment options, are well-tolerated, and improve many signs and symptoms of OIC in patients taking an opioid for chronic noncancer pain.

Muscle ERRγ mitigates Duchenne muscular dystrophy via metabolic and angiogenic reprogramming.

PubMed

Matsakas, Antonios; Yadav, Vikas; Lorca, Sabina; Narkar, Vihang

2013-10-01

Treatment of Duchenne muscular dystrophy (DMD) by replacing mutant dystrophin or restoring dystrophin-associated glycoprotein complex (DAG) has been clinically challenging. Instead, identifying and targeting muscle pathways deregulated in DMD will provide new therapeutic avenues. We report that the expression of nuclear receptor estrogen-related receptor-γ (ERRγ), and its metabolic and angiogenic targets are down-regulated (50-85%) in skeletal muscles of mdx mice (DMD model) vs. wild-type mice. Corelatively, oxidative myofibers, muscle vasculature, and exercise tolerance (33%) are decreased in mdx vs. wild-type mice. Overexpressing ERRγ selectively in the dystrophic muscles of the mdx mice restored metabolic and angiogenic gene expression compared with control mdx mice. Further, ERRγ enhanced muscle oxidative myofibers, vasculature, and blood flow (by 33-66%) and improved exercise tolerance (by 75%) in the dystrophic mice. Restoring muscle ERRγ pathway ameliorated muscle damage and also prevented DMD hallmarks of postexercise muscle damage, hypoxia, and fatigue in mdx mice. Notably, ERRγ did not restore sarcolemmal DAG complex, which is thus dispensable for antidystrophic effects of ERRγ. In summary, ERRγ-dependent metabolic and angiogenic gene program is defective in DMD, and we demonstrate that its restoration is a potential strategy for treating muscular dystrophy.

The Effectiveness of Incorporating a Play-based Intervention to Improve Functional Mobility for a Child with Relapsed Acute Lymphoblastic Leukaemia: A Case Report.

PubMed

Vercher, Paula; Hung, You-Jou; Ko, Mansoo

2016-12-01

Acute lymphoblastic leukaemia (ALL) is one of the most common forms of cancer seen in children, accounting for one-fourth of all childhood cancers. These children typically present with decreased functional mobility, weakened lower extremity muscle strength and reduced exercise endurance and interests because of disease progressions and chemotherapy treatments. The purpose of this case report was to examine the effectiveness of incorporating a play-based physical therapy (PT) intervention programme to improve functional mobility for an inpatient with relapsed ALL undergoing chemotherapy. The patient was a 3-year-old male admitted to the hospital for relapsed ALL. He was diagnosed approximately 1 year earlier for which he had undergone chemotherapy and was later considered in remission at that time. When the patient relapsed, he underwent another round of chemotherapy and was waiting for a bone marrow transplant during his treatment during the course of this case report. For PT intervention, therapeutic exercises were incorporated into play to strengthen his lower extremity strength and muscle endurance. Functional activities were also incorporated into play to improve his aerobic capacity and overall quality of life. Multi-attribute health status classification system (HUI3) utility scores, 6-minute walk test distance (6MWT), lower extremity (LE) strength, transfer and tolerated treatment time were assessed to identify the effect of a PT intervention. Despite experiencing fatigue, the patient completed most of the treatments incorporated into play. After 5 weeks of PT intervention, the participant improved on HUI3 (pre: 0.72 and post: 0.92), 6MWT (pre: 156 ft and post: 489 ft), LE strength (squat), transfer (sit to stand) and tolerated treatment time (pre: 16 minutes and post: 44 minutes). This case report suggests that incorporating a play-based PT intervention programme could be physically tolerable and functionally beneficial for a young child with relapsed ALL undergoing inpatient chemotherapy. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Stent placement for palliation of cor triatriatum dexter in a dog with suspected patent foramen ovale.

PubMed

Barncord, Kristin; Stauthammer, Christopher; Moen, Sean L; Hanson, Melissa; Gruenstein, Daniel H

2016-03-01

An 11 month old spayed, female dog presented with exercise intolerance and cyanosis upon exertion. Echocardiography revealed an imperforate cor triatriatum dexter with mild tricuspid valve dysplasia, an underfilled right ventricle and significant right to left shunting across a presumptive patent foramen ovale. Balloon dilation of the abnormal atrial membrane was initially successful in creating a communication between the right atrial chambers, but stenosis of the original perforation and persistent clinical signs prompted a second intervention. A balloon expandable biliary stent was placed across the abnormal partition, improving caudal venous return to the right ventricle and reducing the right to left shunt. Three months after stent placement, resting oxygen saturation had normalized. Six months after stent placement, exercise tolerance had improved and exertional cyanosis had resolved. Long term follow up will be necessary to assess for remodeling of the right ventricle with improved venous return. Stent placement can be considered as a palliative treatment option for cor triatriatum dexter, especially for stenosis post-balloon dilation. Copyright © 2015 Elsevier B.V. All rights reserved.

Symptom-limited exercise testing causes sustained diastolic dysfunction in patients with coronary disease and low effort tolerance.

PubMed

Fragasso, G; Benti, R; Sciammarella, M; Rossetti, E; Savi, A; Gerundini, P; Chierchia, S L

1991-05-01

Exercise stress testing is routinely used for the noninvasive assessment of coronary artery disease and is considered a safe procedure. However, the provocation of severe ischemia might potentially cause delayed recovery of myocardial function. To investigate the possibility that maximal exercise testing could induce prolonged impairment of left ventricular function, 15 patients with angiographically proved coronary disease and 9 age-matched control subjects with atypical chest pain and normal coronary arteries were studied. Radionuclide ventriculography was performed at rest, at peak exercise, during recovery and 2 and 7 days after exercise. Ejection fraction, peak filling and peak emptying rates and left ventricular wall motion were analyzed. All control subjects had a normal exercise test at maximal work loads and improved left ventricular function on exercise. Patients developed 1 mm ST depression at 217 +/- 161 s at a work load of 70 +/- 30 W and a rate-pressure product of 18,530 +/- 4,465 mm Hg x beats/min. Although exercise was discontinued when angina or equivalent symptoms occurred, in all patients diagnostic ST depression (greater than or equal to 1 mm) developed much earlier than symptoms. Predictably, at peak exercise patients showed a decrease in ejection fraction and peak emptying and filling rates. Ejection fraction and peak emptying rate normalized within the recovery period, whereas peak filling rate remained depressed throughout recovery (p less than 0.002) and was still reduced 2 days after exercise (p less than 0.02). In conclusion, in patients with severe impairement of coronary flow reserve, maximal exercise may cause sustained impairement of diastolic function.(ABSTRACT TRUNCATED AT 250 WORDS)

Regular Exercise Reduces Endothelial Cortical Stiffness in Western Diet-Fed Female Mice.

PubMed

Padilla, Jaume; Ramirez-Perez, Francisco I; Habibi, Javad; Bostick, Brian; Aroor, Annayya R; Hayden, Melvin R; Jia, Guanghong; Garro, Mona; DeMarco, Vincent G; Manrique, Camila; Booth, Frank W; Martinez-Lemus, Luis A; Sowers, James R

2016-11-01

We recently showed that Western diet-induced obesity and insulin resistance promotes endothelial cortical stiffness in young female mice. Herein, we tested the hypothesis that regular aerobic exercise would attenuate the development of endothelial and whole artery stiffness in female Western diet-fed mice. Four-week-old C57BL/6 mice were randomized into sedentary (ie, caged confined, n=6) or regular exercise (ie, access to running wheels, n=7) conditions for 16 weeks. Exercise training improved glucose tolerance in the absence of changes in body weight and body composition. Compared with sedentary mice, exercise-trained mice exhibited reduced endothelial cortical stiffness in aortic explants (sedentary 11.9±1.7 kPa versus exercise 5.5±1.0 kPa; P<0.05), as assessed by atomic force microscopy. This effect of exercise was not accompanied by changes in aortic pulse wave velocity (P>0.05), an in vivo measure of aortic stiffness. In comparison, exercise reduced femoral artery stiffness in isolated pressurized arteries and led to an increase in femoral internal artery diameter and wall cross-sectional area (P<0.05), indicative of outward hypertrophic remodeling. These effects of exercise were associated with an increase in femoral artery elastin content and increased number of fenestrae in the internal elastic lamina (P<0.05). Collectively, these data demonstrate for the first time that the aortic endothelium is highly plastic and, thus, amenable to reductions in stiffness with regular aerobic exercise in the absence of changes in in vivo whole aortic stiffness. Comparatively, the same level of exercise caused destiffening effects in peripheral muscular arteries, such as the femoral artery, that perfuse the working limbs. © 2016 American Heart Association, Inc.

A 12-week sports-based exercise programme for inactive Indigenous Australian men improved clinical risk factors associated with type 2 diabetes mellitus.

PubMed

Mendham, Amy E; Duffield, Rob; Marino, Frank; Coutts, Aaron J

2015-07-01

This study assessed the effect of a 12-week sports-based exercise intervention on glucose regulation, anthropometry and inflammatory markers associated with the prevalence of type 2 diabetes mellitus (T2DM) in Indigenous Australian men. Twenty-six inactive Indigenous Australian men (48.6±6.6 years) were randomized into exercise (n=16) or control (n=10)conditions. Training included ∼2-3 days/week for 12 weeks of sports and gym exercises in a group environment, whilst control participants maintained normal activity and dietary patterns. Pre- and post-intervention testing included: anthropometry, peak aerobic capacity, fasting blood chemistry of inflammatory cytokines, adiponectin, leptin, cholesterol, glucose, insulin and C-peptide. An oral glucose tolerance test measured glucose, insulin and C-peptide 30, 60, 90 and 120min post 75g glucose ingestion. The exercise condition decreased insulin area under the curve (25±22%), increased estimated insulin sensitivity (35±62%) and decreased insulin resistance (9±35%; p<0.05), compared with control (p>0.05). The exercise condition decreased in body mass index, waist circumference and waist to hip ratio (p<0.05), compared to control (p>0.05). Leptin decreased in the exercise group, with no changes for adiponectin (p>0.05) or inflammatory markers (p>0.05) in either condition. Aerobic fitness variables showed significant increases in peak oxygen consumption for the exercise condition compared to no change in control (p>0.05). Findings indicate positive clinical outcomes in metabolic, anthropometric and aerobic fitness variables. This study provides evidence for sport and group-based activities leading to improved clinical risk factors associated with T2DM development in clinically obese Indigenous Australian men. Copyright © 2014 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

The Exercise Capacity of Blind Children.

ERIC Educational Resources Information Center

Jankowski, L. W.; Evans, J. K.

1981-01-01

To determine whether blind children in a well-equipped modern institution are receiving enough physical education activities to maintain good physical condition, the physiological characteristics of 20 institutionalized blind children were measured according to body composition, pulmonary function, and tolerance for exercise. (Author)

The Case for Increased Physical Activity in Chronic Inflammatory Bowel Disease: A Brief Review.

PubMed

Shephard, R J

2016-06-01

Regular physical activity reduces the risk of colon cancer, but there is little information on the merits of such activity in the prevention and management of chronic inflammatory bowel disease (CIBD). The present systematic review thus documents current levels of habitual physical activity and aerobic and muscular function in CIBD, and examines the safety, practicality and efficacy of exercise programmes in countering the disease process, correcting functional deficits and enhancing quality of life. A systematic search of the Ovid/Medline database from January 1996 to May 2015 linked the terms physical activity/motor activity/physical fitness/physical training/physical education/training/exercise/exercise therapy with Crohn's disease/colitis/ulcerative colitis/inflammatory bowel disease, supplementing this information by a scanning of reference lists and personal files.12 of 16 published studies show a low level of habitual physical activity in CIBD, with sub-normal values for aerobic power, lean tissue mass and muscular strength. 3 of 4 studies suggest physical activity may reduce the risk of developing IBD, and 11 interventions all note that exercise programmes are well tolerated with some decreases of disease activity, and functional gains leading to an increased health-related quality of life. Moreover, programme compliance rates compare favourably with those seen in the treatment of other chronic conditions. More information on mechanisms is needed, but regular moderate aerobic and/or resistance exercise improves the health status of patients with CIBD both by modulating immune function and by improving physical function. A regular exercise programme should thus become an important component in the management of CIBD. © Georg Thieme Verlag KG Stuttgart · New York.

High, but not low, exercise volume shifts the balance of renin-angiotensin system toward ACE2/Mas receptor axis in skeletal muscle in obese rats.

PubMed

Frantz, Eliete Dalla Corte; Giori, Isabele Gomes; Machado, Marcus Vinícius; Magliano, D'Angelo Carlo; Freitas, Fernanda Marques; Andrade, Mariana Sodré Boêta; Vieira, Aline Bomfim; Nóbrega, Antonio Claudio Lucas; Tibiriçá, Eduardo

2017-10-01

Metabolic syndrome is a cluster of metabolic risk factors that is linked to central obesity, elevated blood pressure, insulin resistance (IR), and dyslipidemia, where the renin-angiotensin system (RAS) may provide a link among them. This study aimed to evaluate volume exercise effects comparing low vs. high volume of chronic aerobic exercise on RAS axes in skeletal muscle in a diet-induced obesity (DIO) rat model. For this, male Wistar-Kyoto rats were fed a standard chow (SC) diet or a high-fat (HF) diet for 32 wk. Animals receiving the HF diet were randomly divided into low exercise volume (LEV, 150 min/wk) and high exercise volume (HEV, 300 min/wk) at the 20th week. After 12 wk of aerobic treadmill training, the body mass and composition, blood pressure, glucose and lipid metabolism, RAS axes, insulin signaling, and inflammatory pathway were performed. HEV slowed the body mass gain, reduced intra-abdominal fat pad and leptin levels, improved total and peripheral body composition and inflammatory cytokine, reduced angiotensin II type 1 receptor expression, and increased Mas receptor protein expression compared with the HF animals. Sedentary groups (SC and HF) presented lower time to exhaustion and maximal velocity compared with the LEV and HEV groups. Both exercise training groups showed reduced resting systolic blood pressure and heart rate, improved glucose tolerance, IR, insulin signaling, and lipid profile. We conclude that the HEV, but not LEV, shifted the balance of RAS toward the ACE2/Mas receptor axis in skeletal muscle, presenting protective effects against the DIO model. Copyright © 2017 the American Physiological Society.

Effects of transcatheter closure of Fontan fenestration on exercise tolerance. kidecho@yahoo.com.

PubMed

Momenah, Tarek S; Eltayb, Haifa; Oakley, Reida El; Qethamy, Howeida Al; Faraidi, Yahya Al

2008-05-01

Baffle fenestration is associated with a significantly better outcome in standard and high-risk patients undergoing completion of Fontan. We report the effects of subsequent transcatheter closure of fenestration on exercise capacity and oxygen saturation. Sixteen patients with a mean age of 10.3 years underwent Amplatzer septal occluder (ASO) device transcatheter closure of Fontan fenestration. All had a fenestrated Fontan operation 6 month to 8 years prior to the procedure. A stress test was performed before and after device closure of fenestration in 14 patients (2 patients did not tolerate stress test before the procedure). The fenestrations in all patients were successfully occluded with the use of the Amplatzer device occluder. No complications occurred during or after the procedure. O2 saturation increased from a mean 85.1 +/- 7.89% to 94.5 +/- 3.63% (p < 0.01) at rest and from 66.2 +/- 12.86% to 87.2 +/- 8.64% (p < 0.01) following exercise. Exercise duration has also increased from 8.22 +/- 2.74 min to 10.29 +/- 1.91 min (p < 0.05). Transcatheter closure of Fontan fenestration increases the duration of exercise capacity and increases O2 saturation at rest and after exercise.

Intraspecific individual variation of temperature tolerance associated with oxygen demand in the European sea bass (Dicentrarchus labrax)

PubMed Central

Ozolina, Karlina; Shiels, Holly A; Ollivier, Hélène; Claireaux, Guy

2016-01-01

Abstract The European sea bass (Dicentrarchus labrax) is an economically important fish native to the Mediterranean and Northern Atlantic. Its complex life cycle involves many migrations through temperature gradients that affect the energetic demands of swimming. Previous studies have shown large intraspecific variation in swimming performance and temperature tolerance, which could include deleterious and advantageous traits under the evolutionary pressure of climate change. However, little is known of the underlying determinants of this individual variation. We investigated individual variation in temperature tolerance in 30 sea bass by exposing them to a warm temperature challenge test. The eight most temperature-tolerant and eight most temperature-sensitive fish were then studied further to determine maximal swimming speed (UCAT), aerobic scope and post-exercise oxygen consumption. Finally, ventricular contractility in each group was determined using isometric muscle preparations. The temperature-tolerant fish showed lower resting oxygen consumption rates, possessed larger hearts and initially recovered from exhaustive exercise faster than the temperature-sensitive fish. Thus, whole-animal temperature tolerance was associated with important performance traits. However, the temperature-tolerant fish also demonstrated poorer maximal swimming capacity (i.e. lower UCAT) than their temperature-sensitive counterparts, which may indicate a trade-off between temperature tolerance and swimming performance. Interestingly, the larger relative ventricular mass of the temperature-tolerant fish did not equate to greater ventricular contractility, suggesting that larger stroke volumes, rather than greater contractile strength, may be associated with thermal tolerance in this species. PMID:27382468

Intraspecific individual variation of temperature tolerance associated with oxygen demand in the European sea bass (Dicentrarchus labrax).

PubMed

Ozolina, Karlina; Shiels, Holly A; Ollivier, Hélène; Claireaux, Guy

2016-01-01

The European sea bass (Dicentrarchus labrax) is an economically important fish native to the Mediterranean and Northern Atlantic. Its complex life cycle involves many migrations through temperature gradients that affect the energetic demands of swimming. Previous studies have shown large intraspecific variation in swimming performance and temperature tolerance, which could include deleterious and advantageous traits under the evolutionary pressure of climate change. However, little is known of the underlying determinants of this individual variation. We investigated individual variation in temperature tolerance in 30 sea bass by exposing them to a warm temperature challenge test. The eight most temperature-tolerant and eight most temperature-sensitive fish were then studied further to determine maximal swimming speed (U CAT), aerobic scope and post-exercise oxygen consumption. Finally, ventricular contractility in each group was determined using isometric muscle preparations. The temperature-tolerant fish showed lower resting oxygen consumption rates, possessed larger hearts and initially recovered from exhaustive exercise faster than the temperature-sensitive fish. Thus, whole-animal temperature tolerance was associated with important performance traits. However, the temperature-tolerant fish also demonstrated poorer maximal swimming capacity (i.e. lower U CAT) than their temperature-sensitive counterparts, which may indicate a trade-off between temperature tolerance and swimming performance. Interestingly, the larger relative ventricular mass of the temperature-tolerant fish did not equate to greater ventricular contractility, suggesting that larger stroke volumes, rather than greater contractile strength, may be associated with thermal tolerance in this species.

Bronchoscopic Lung Volume Reduction with Endobronchial Valves in Low-FEV1 Patients.

PubMed

Darwiche, Kaid; Karpf-Wissel, Rüdiger; Eisenmann, Stephan; Aigner, Clemens; Welter, Stefan; Zarogoulidis, Paul; Hohenforst-Schmidt, Wolfgang; Freitag, Lutz; Oezkan, Filiz

2016-01-01

Bronchoscopic lung volume reduction (BLVR) with valves has been shown to improve lung function, exercise capacity, and quality of life in patients with emphysema, but only few patients with forced expiratory volume in 1 s (FEV1) ≤20% predicted have been included in former studies. Although the procedure can be performed safely, pneumothorax is a frequent complication, which can be critical for these very severely diseased patients. The aim of the study was to assess the safety of BLVR in patients with a very advanced stage of emphysema, as indicated by FEV1 ≤20% predicted. Patients in whom BLVR was performed between January 2013 and August 2015 were included in this analysis if their baseline predicted FEV1 was ≤20%. BLVR, performed only if collateral ventilation was absent, achieved complete occlusion of the target lobe. All patients were closely monitored and were not discharged before the fourth day after BLVR. Twenty patients with FEV1 ≤20% predicted were included in the analysis. Lung volume reduction was achieved in 65% of the cases. Pneumothorax occurred in 4 cases (20%). No patient died. Lung function and exercise tolerance improved after 1 and 3 months, respectively. BLVR with valves can be safely performed in patients with FEV1 ≤20% predicted when close postprocedural monitoring is provided. Improvement in lung function and exercise capacity can be achieved. © 2016 S. Karger AG, Basel.

Self-reported tolerance influences prefrontal cortex hemodynamics and affective responses.

PubMed

Tempest, Gavin; Parfitt, Gaynor

2016-02-01

The relationship between cognitive and sensory processes in the brain contributes to the regulation of affective responses (pleasure-displeasure). Exercise can be used to manipulate sensory processes (by increasing physiological demand) in order to examine the role of dispositional traits that may influence an individual's ability to cognitively regulate these responses. With the use of near infrared spectroscopy, in this study we examined the influence of self-reported tolerance upon prefrontal cortex (PFC) hemodynamics and affective responses. The hemodynamic response was measured in individuals with high or low tolerance during an incremental exercise test. Sensory manipulation was standardized against metabolic processes (ventilatory threshold [VT] and respiratory compensation point [RCP]), and affective responses were recorded. The results showed that the high-tolerance group displayed a larger hemodynamic response within the right PFC above VT (which increased above RCP). The low-tolerance group showed a larger hemodynamic response within the left PFC above VT. The high-tolerance group reported a more positive/less negative affective response above VT. These findings provide direct neurophysiological evidence of differential hemodynamic responses within the PFC that are associated with tolerance in the presence of increased physiological demands. This study supports the role of dispositional traits and previous theorizing into the underlying mechanisms (cognitive vs. sensory processes) of affective responses.

Aerobic Exercise Training in Very Severe Chronic Obstructive Pulmonary Disease: A Systematic Review and Meta-Analysis.

PubMed

Paneroni, Mara; Simonelli, Carla; Vitacca, Michele; Ambrosino, Nicolino

2017-08-01

To evaluate the effectiveness of exercise training in patients with very severe chronic obstructive pulmonary disease (COPD). We searched MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, and Cumulative Index to Nursing and Allied Health Literature databases using the following as search terms: COPD, Chronic Obstructive Pulmonary Disease, Exercise, and Pulmonary Rehabilitation. We included randomized controlled trials (RCTs) of subjects with forced expiratory volume in the first second of less than 35% of the predicted normal value enrolled in in-patient, outpatient, or home- or community-based training programs lasting at least 4 weeks with respect to usual care. We included RCTs with outcome measures including the 6-minute walking test and/or health-related quality of life assessed by the St. George's Respiratory Questionnaire (SGRQ). Of 580 articles screened, 10 were included. The programs' duration ranged from 4 to 52 weeks with 1 to 5 sessions per week lasting 15 to 40 minutes each. The intervention group improved in 6-minute walking test [weighted mean difference, 67.1 (95% confidence interval [CI], 37.897-98.927); standardized mean difference, 3.86 (95% CI, 2.04-5.67)], and St. George's Respiratory Questionnaire [weighted mean difference, -8.041 (95% CI, -15.273 to -0.809); standardized mean difference, -1.23 (95% CI, -2.14 to -0.31)]. Exercise training improves exercise tolerance and health-related quality of life in patients with very severe COPD. However, because few studies on severely affected patients are available and the training programs are Highly heterogeneous, larger RCTs are needed.

Does the use of Nintendo Wii SportsTM improve arm function? Trial of WiiTM in Stroke: a randomized controlled trial and economics analysis.

PubMed

Adie, Katja; Schofield, Christine; Berrow, Margie; Wingham, Jennifer; Humfryes, John; Pritchard, Colin; James, Martin; Allison, Rhoda

2017-02-01

The Trial of Wii™ in Stroke investigated the efficacy of using the Nintendo Wii Sports™ (Wii TM ) to improve affected arm function after stroke. Multicentre, pragmatic, parallel group, randomized controlled trial. Home-based rehabilitation. A total of 240 participants aged 24-90 years with arm weakness following a stroke within the previous six months. Participants were randomly assigned to exercise daily for six weeks using the Wii TM or arm exercises at home. Primary outcome was change in the affected arm function at six weeks follow-up using the Action Research Arm Test. Secondary outcomes included occupational performance, quality of life, arm function at six months and a cost effectiveness analysis. The study was completed by 209 participants (87.1%). There was no significant difference in the primary outcome of affected arm function at six weeks follow-up (mean difference -1.7, 95% CI -3.9 to 0.5, p = 0.12) and no significant difference in secondary outcomes, including occupational performance, quality of life or arm function at six months, between the two groups. No serious adverse events related to the study treatment were reported. The cost effectiveness analysis showed that the Wii TM was more expensive than arm exercises £1106 (SD 1656) vs. £730 (SD 829) (probability 0.866). The trial showed that the Wii TM was not superior to arm exercises in home-based rehabilitation for stroke survivors with arm weakness. The Wii TM was well tolerated but more expensive than arm exercises.

Exercise and type 2 diabetes: new prescription for an old problem.

PubMed

Bird, Stephen R; Hawley, John A

2012-08-01

During the past 50 years, the prevalence of a cluster of chronic, inactivity-related diseases including obesity, insulin resistance and type 2 diabetes mellitus (T2DM), collectively referred to as 'metabolic syndrome' (MetS) has reached global epidemic proportions. Appropriate exercise training is a clinically proven, cost-effective, primary intervention that delays and in many cases prevents the health burdens associated with MetS. Indeed, there is no single intervention with greater efficacy than physical exercise to reduce the risk of virtually all chronic diseases simultaneously. However compliance to National guidelines for physical activity remains low, with "a lack of time" the most frequently cited barrier to exercise participation by adults, irrespective of age, sex and ethnic background. Part of the growing apathy to modify lifestyle habits is that current public health recommendations may be unrealistic and unattainable for the majority of the populace. Hence, there is an urgent need for innovations in exercise prescription that can be incorporated into daily living and induce clinically beneficial health outcomes. Here we focus attention on a novel form of exercise prescription, high-intensity interval training (HIT), and provide evidence that HIT is a time-efficient and well-tolerated therapeutic intervention to improve cardio-metabolic health in a number of pre-clinical and clinical populations. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Effect of dehydroepiandrosterone administration on recovery from mix-type exercise training-induced muscle damage.

PubMed

Liao, Yi-Hung; Liao, Kun-Fu; Kao, Chung-Lan; Chen, Chung-Yu; Huang, Chih-Yang; Chang, Wei-Hsiang; Ivy, John L; Bernard, Jeffrey R; Lee, Shin-Da; Kuo, Chia-Hua

2013-01-01

This study aimed to determine the role of DHEA-S in coping against the exercise training mixing aerobic and resistance components. During 5-day successive exercise training, 16 young male participants (19.2 ± 1.2 years) received either a placebo (flour capsule) or DHEA (100 mg/day) in a double-blinded and placebo-controlled design. Oral DHEA supplementation significantly increased circulating DHEA-S by 2.5-fold, but a protracted drop (~35 %) was observed from Day 3 during training. In the Placebo group, only a minimal DHEA-S reduction (~17 %) was observed. Changes in testosterone followed a similar pattern as DHEA-S. Muscle soreness was elevated significantly on Day 2 for both groups to a similar extent. Lower muscle soreness was observed in the DHEA-supplemented group on Day 3 and Day 6. In the Placebo group, training increased circulating creatine kinase (CK) levels by approximately ninefold, while only a threefold increase was observed in the DHEA-supplemented group. This mix-type exercise training improved glucose tolerance in both groups, while lowering the insulin response to the glucose challenge, but no difference between treatments was observed. Our results suggest that DHEA-S may play a role in protecting skeletal muscle from exercise training-induced muscle damage.

Advances in the Evaluation of Respiratory Pathophysiology during Exercise in Chronic Lung Diseases

PubMed Central

O'Donnell, Denis E.; Elbehairy, Amany F.; Berton, Danilo C.; Domnik, Nicolle J.; Neder, J. Alberto

2017-01-01

Dyspnea and exercise limitation are among the most common symptoms experienced by patients with various chronic lung diseases and are linked to poor quality of life. Our understanding of the source and nature of perceived respiratory discomfort and exercise intolerance in chronic lung diseases has increased substantially in recent years. These new mechanistic insights are the primary focus of the current review. Cardiopulmonary exercise testing (CPET) provides a unique opportunity to objectively evaluate the ability of the respiratory system to respond to imposed incremental physiological stress. In addition to measuring aerobic capacity and quantifying an individual's cardiac and ventilatory reserves, we have expanded the role of CPET to include evaluation of symptom intensity, together with a simple “non-invasive” assessment of relevant ventilatory control parameters and dynamic respiratory mechanics during standardized incremental tests to tolerance. This review explores the application of the new advances in the clinical evaluation of the pathophysiology of exercise intolerance in chronic obstructive pulmonary disease (COPD), chronic asthma, interstitial lung disease (ILD) and pulmonary arterial hypertension (PAH). We hope to demonstrate how this novel approach to CPET interpretation, which includes a quantification of activity-related dyspnea and evaluation of its underlying mechanisms, enhances our ability to meaningfully intervene to improve quality of life in these pathologically-distinct conditions. PMID:28275353

Very short/short-term benefit of inpatient/outpatient cardiac rehabilitation programs after coronary artery bypass grafting surgery.

PubMed

Spiroski, Dejan; Andjić, Mojsije; Stojanović, Olivera Ilić; Lazović, Milica; Dikić, Ana Djordjević; Ostojić, Miodrag; Beleslin, Branko; Kostić, Snežana; Zdravković, Marija; Lović, Dragan

2017-05-01

Exercise-based rehabilitation is an important part of treatment patients following coronary artery bypass graft (CABG) surgery. To evaluate effect of very short/short-term exercise training on cardiopulmonary exercise testing (CPET) parameters. We studied 54 consecutive patients with myocardial infarction (MI) treated with CABG surgery referred for rehabilitation. The study population consisted of 50 men and 4 women (age 57.72 ± 7.61 years, left ventricular ejection fraction 55% ± 5.81%), who participated in a 3-week clinical and 6-month outpatient cardiac rehabilitation program. The Inpatient program consisted of cycling 7 times/week and daily walking for 45 minutes. The outpatient program consisted mainly of walking 5 times/week for 45 minutes and cycling 3 times/week. All patients performed symptom-limited CPET on a bicycle ergometer with a ramp protocol of 10 W/minute at the start, for 3 weeks, and for 6 months. After 3 weeks of an exercise-based cardiac rehabilitation program, exercise tolerance improved as compared to baseline, as well as peak respiratory exchange ratio. Most importantly, peak VO 2 (16.35 ± 3.83 vs 17.88 ± 4.25 mL/kg/min, respectively, P < 0.05), peak VCO 2 (1.48 ± 0.40 vs 1.68 ± 0.43, respectively, P < 0.05), peak ventilatory exchange (44.52 ± 11.32 vs 52.56 ± 12.37 L/min, respectively, P < 0.05), and peak breathing reserve (52.00% ± 13.73% vs 45.75% ± 14.84%, respectively, P < 0.05) were also improved. The same improvement trend continued after 6 months (respectively, P < 0.001 and P < 0.0001). No major adverse cardiac events were noted during the rehabilitation program. Very short/short-term exercise training in patients with MI treated with CABG surgery is safe and improves functional capacity. © 2017 Wiley Periodicals, Inc.

Greater endurance capacity and improved dyspnoea with acute oxygen supplementation in idiopathic pulmonary fibrosis patients without resting hypoxaemia.

PubMed

Dowman, Leona M; McDonald, Christine F; Bozinovski, Steven; Vlahos, Ross; Gillies, Rebecca; Pouniotis, Dodie; Hill, Catherine J; Goh, Nicole S L; Holland, Anne E

2017-07-01

Supplemental oxygen is commonly prescribed in patients with idiopathic pulmonary fibrosis (IPF), although its benefits have not been proven. The aims of this study were to investigate the effect of oxygen on oxidative stress, cytokine production, skeletal muscle metabolism and physiological response to exercise in IPF. Eleven participants with IPF received either oxygen, at an FiO 2 of 0.50, or compressed air for 1 h at rest and during a cycle endurance test at 85% of peak work rate. Blood samples collected at rest and during exercise were analysed for markers of oxidative stress, skeletal muscle metabolism and cytokines. The protocol was repeated a week later with the alternate intervention. Compared with air, oxygen did not adversely affect biomarker concentrations at rest and significantly improved endurance time (mean difference = 99 ± 81s, P = 0.002), dyspnoea (-1 ± 1 U, P = 0.02), systolic blood pressure (BP; -11 ± 11 mm Hg, P = 0.006), nadir oxyhaemoglobin saturation (SpO 2 ; 8 ± 6%, P = 0.001), SpO 2 at 2-min (7 ± 6%, P = 0.003) and 5-min isotimes (5 ± 3, P < 0.001) and peak exercise xanthine concentrations (-42 ± 73 µmol/L, P = 0.03). Air significantly increased IL-10 (5 ± 5 pg/mL, P = 0.04) at 2-min isotime. Thiobarbituric acid-reactive substances (TBARs), IL-6, TNF-α, creatine kinase, lactate, heart rate and fatigue did not differ between the two interventions at any time point. In patients with IPF, breathing oxygen at FiO 2 of 0.50 at rest seems safe. During exercise, oxygen improves exercise tolerance, alleviates exercise-induced hypoxaemia and reduces dyspnoea. A potential relationship between oxygen administration and improved skeletal muscle metabolism should be explored in future studies. © 2017 Asian Pacific Society of Respirology.

Effects of exercise amount and intensity on abdominal obesity and glucose tolerance in obese adults: a randomized trial.

PubMed

Ross, Robert; Hudson, Robert; Stotz, Paula J; Lam, Miu

2015-03-03

Exercise reduces obesity and related glucose tolerance, but whether increasing exercise intensity offers additional benefit at fixed exercise amounts is unknown. To determine the separate effects of exercise amount and intensity on abdominal obesity and glucose tolerance. 24-week, single-center, parallel-group trial from 2009 to 2013. (ClinicalTrials.gov: NCT00955071). Kingston, Ontario, Canada. 300 abdominally obese adults. Control (no exercise) (n = 75) or 5 weekly sessions of low-amount, low-intensity exercise (LALI) (180 and 300 kcal/session for women and men, respectively, at 50% of maximum oxygen consumption [V̇o2peak]) (n = 73); high-amount, low-intensity exercise (HALI) (360 and 600 kcal/session, respectively, at 50% of V̇o2peak) (n = 76); or high-amount, high-intensity exercise (HAHI) (360 and 600 kcal/session, respectively, at 75% of V̇o2peak) (n = 76). Daily unsupervised physical activity and sedentary time were measured by accelerometer. Waist circumference and 2-hour glucose level (primary outcomes) and cardiorespiratory fitness and measures of insulin action (secondary measurements). 217 participants (72.3%) completed the intervention. Mean exercise time in minutes per session was 31 (SD, 4.4) for LALI, 58 (SD, 7.6) for HALI, and 40 (SD, 6.2) for HAHI. Daily unsupervised physical activity and sedentary time did not change in any exercise group versus control (P > 0.33). After adjustment for age and sex in a linear mixed model, reductions in waist circumference were greater in the LALI (-3.9 cm [95% CI, -5.6 to -2.3 cm]; P < 0.001), HALI (-4.6 cm [CI, -6.2 to -3.0 cm]; P < 0.001), and HAHI (-4.6 cm [CI, -6.3 to -2.9 cm]; P < 0.001) groups than the control group but did not differ among the exercise groups (P > 0.43). After adjustment for covariates, reductions in 2-hour glucose level were greater in the HAHI group (-0.7 mmol/L [-12.5 mg/dL] [CI, -1.3 to -0.1 mmol/L {-23.5 to -1.5 mg/dL}]; P = 0.027) than the control group but did not differ for the LALI or HALI group versus the control group (P > 0.159). Weight loss was greater in all exercise groups than the control group (P < 0.001); however, reduction in body weight did not differ among the exercise groups (P > 0.182). The clinical importance of reducing 2-hour glucose level in nondiabetic adults remains undetermined. Fixed amounts of exercise independent of exercise intensity resulted in similar reductions in abdominal obesity. Reduction in 2-hour glucose level was restricted to high-intensity exercise.

Can the use of creatine supplementation attenuate muscle loss in cachexia and wasting?

PubMed

Sakkas, Giorgos K; Schambelan, Morris; Mulligan, Kathleen

2009-11-01

Weight loss and low BMI due to an underlying illness have been associated with increased mortality, reduced functional capacity, and diminished quality of life. There is a need for well tolerated, long-term approaches to maintain body weight in patients with cachexia or wasting. The purpose of this review is to highlight the scientific and clinical evidence derived from the recent literature investigating the rationale for and potential medical use of creatine supplementation in patients with cachexia or wasting. Some studies have demonstrated that supplementation with creatine can increase creatine reserves in skeletal muscle and increase muscle mass and performance in various disease states that affect muscle size and function. The mechanisms underlying these effects are not clear. It has been suggested that creatine supplementation may increase intramuscular phosphocreatine stores and promote more rapid recovery of adenosine triphosphate levels following exercise, thus allowing users to exercise for longer periods or at higher intensity levels. Other hypothesized mechanisms include attenuation of proinflammatory cytokines, stimulation of satellite cell proliferation and upregulation of genes that promote protein synthesis and cell repair. Creatine is a generally well tolerated, low-cost, over-the-counter nutritional supplement that shows potential in improving lean body mass and functionality in patients with wasting diseases. However, placebo-controlled studies have shown variable effects, with improvements in some and not in others. Additional studies with longer follow-up are required to identify the populations that might benefit most from creatine supplementation.

[Adaptation to hypoxia and hyperoxia improves physical endurance: the role of reactive oxygen species and redox-signaling].

PubMed

Sazontova, T G; Glazachev, O S; Bolotova, A V; Dudnik, E N; Striapko, N V; Bedareva, I V; Anchishkina, N A; Arkhipenko, Iu V

2012-06-01

We have conducted theoretical foundation, experimental analysis and a pilot study of a new method of adaptation to hypoxia and hyperoxia in the prevention of hypoxic and stress-induced disorders and improving the body's tolerance to physical stress. It has been shown in the experimental part that a combination of physical exercise with adaptation to hypoxia-hyperoxia significantly increased tolerance to acute physical load (APL) and its active phase. Analysis of lipid peroxidation processes, antioxidant enzymes and HSPs showed that short-term training for physical exercise by itself compensates the stressor, but not the hypoxic component of the APL, the combination of training with adaptation to hypoxia-hyperoxia completely normalizes the stressor and hypoxic components of APL. The pilot study has been performed to evaluate the effectiveness of hypoxic-hyperoxic training course in qualified young athletes with over-training syndrome. After completing the course of hypoxia-hyperoxia adaptation, 14 sessions, accompanied by light mode sports training, the athletes set the normalization of autonomic balance, increased resistance to acute hypoxia in hypoxic test, increased physical performance--increased PWC170, maximal oxygen consumption (VO2max) parameters, their relative values to body mass, diminished shift of rate pressure product in the load. Thus, we confirmed experimental findings that hypoxic-hyperoxic training optimizes hypoxic (increased athletes resistance to proper hypoxia) and stress (myocardium economy in acute physical stress testing) components in systemic adaptation and restoration of athletes' with over-training syndrome.

Dietary chromium tripicolinate supplementation reduces glucose concentrations and improves glucose tolerance in normal-weight cats.

PubMed

Appleton, D J; Rand, J S; Sunvold, G D; Priest, J

2002-03-01

The effect of dietary chromium supplementation on glucose and insulin metabolism in healthy, non-obese cats was evaluated. Thirty-two cats were randomly divided into four groups and fed experimental diets consisting of a standard diet with 0 ppb (control), 150 ppb, 300 ppb, or 600 ppb added chromium as chromium tripicolinate. Intravenous glucose tolerance, insulin tolerance and insulin sensitivity tests with minimal model analysis were performed before and after 6 weeks of feeding the test diets. During the glucose tolerance test, glucose concentrations, area under the glucose concentration-time curve, and glucose half-life (300 ppb only), were significantly lower after the trial in cats supplemented with 300 ppb and 600 ppb chromium, compared with values before the trial. Fasting glucose concentrations measured on a different day in the biochemistry profile were also significantly lower after supplementation with 600 ppb chromium. There were no significant differences in insulin concentrations or indices in either the glucose or insulin tolerance tests following chromium supplementation, nor were there any differences between groups before or after the dietary trial.Importantly, this study has shown a small but significant, dose-dependent improvement in glucose tolerance in healthy, non-obese cats supplemented with dietary chromium. Further long-term studies are warranted to determine if the addition of chromium to feline diets is advantageous. Cats most likely to benefit are those with glucose intolerance and insulin resistance from lack of exercise, obesity and old age. Healthy cats at risk of glucose intolerance and diabetes from underlying low insulin sensitivity or genetic factors may also benefit from long-term chromium supplementation. Copyright 2002 ESFM and AAFP.

Effect of Exercise Training on Red Blood Cell Distribution Width as a Marker of Impaired Exercise Tolerance in Patients With Coronary Artery Disease.

PubMed

Nishiyama, Yasuhiro; Niiyama, Hiroshi; Harada, Haruhito; Katou, Atsushi; Yoshida, Noriko; Ikeda, Hisao

2016-09-28

Red blood cell distribution width (RDW) can predict mortality in cardiovascular disease. However, the underlying mechanisms of the beneficial prognostic marker remain unknown. The purpose of this study was to investigate whether the RDW is related to impaired exercise tolerance and exercise training (ET) effect on RDW in patients with coronary artery disease (CAD).Seventy-eight patients who underwent ET by supervised bicycle ergometer during 3 weeks served as the ET group whereas 30 patients who did not undergo ET were the control group. Exercise stress test with cardiopulmonary analysis was performed in the ET group. Peak oxygen uptake (from 14.1 ± 4.0 to 15.1 ± 3.8 mL/kg/minute, P < 0.05) significantly increased in the ET group. Although RDW and serum erythropoietin concentration (EP) before the observation period did not differ between the ET and control groups, RDW (from 44.4 ± 4.7 to 43.4 ± 3.8 fL, P < 0.01) and EP (from 27.9 ± 15.8 to 22.9 ± 8.2 mIU/mL, P < 0.005) significantly decreased in the ET group, however, these parameters did not change in the control group. In the ET group, RDW was negatively correlated with peak oxygen uptake (r = -0.55, P < 0.01) and the changes in RDW before and after ET were positively correlated with the changes in EP (r = 0.39, P < 0.005).Thus, ET increases exercise tolerance and decreases RDW in association with increased oxygen uptake in patients with CAD.

Prior exercise alters the difference between arterialised and venous glycaemia: implications for blood sampling procedures.

PubMed

Edinburgh, Robert M; Hengist, Aaron; Smith, Harry A; Betts, James A; Thompson, Dylan; Walhin, Jean-Philippe; Gonzalez, Javier T

2017-05-01

Oral glucose tolerance and insulin sensitivity are common measures, but are determined using various blood sampling methods, employed under many different experimental conditions. This study established whether measures of oral glucose tolerance and oral glucose-derived insulin sensitivity (insulin sensitivity indices; ISI) differ when calculated from venous v. arterialised blood. Critically, we also established whether any differences between sampling methods are consistent across distinct metabolic conditions (after rest v. after exercise). A total of ten healthy men completed two trials in a randomised order, each consisting of a 120-min oral glucose tolerance test (OGTT), either at rest or post-exercise. Blood was sampled simultaneously from a heated hand (arterialised) and an antecubital vein of the contralateral arm (venous). Under both conditions, glucose time-averaged AUC was greater from arterialised compared with venous plasma but importantly, this difference was larger after rest relative to after exercise (0·99 (sd 0·46) v. 0·56 (sd 0·24) mmol/l, respectively; P<0·01). OGTT-derived ISIMatsuda and ISICederholm were lower when calculated from arterialised relative to venous plasma and the arterialised-venous difference was greater after rest v. after exercise (ISIMatsuda: 1·97 (sd 0·81) v. 1·35 (sd 0·57) arbitrary units (au), respectively; ISICederholm : 14·76 (sd 7·83) v. 8·70 (sd 3·95) au, respectively; both P<0·01). Venous blood provides lower postprandial glucose concentrations and higher estimates of insulin sensitivity, compared with arterialised blood. Most importantly, these differences between blood sampling methods are not consistent after rest v. post-exercise, preventing standardised venous-to-arterialised corrections from being readily applied.

A Comparison of the Effects of Aerobic and Intense Exercise on the Type 2 Diabetes Mellitus Risk Marker Adipokines, Adiponectin and Retinol Binding Protein-4

PubMed Central

Phillips, Amy

2014-01-01

With a more sedentary population comes growing rates of obesity and increased type 2 diabetes mellitus (T2DM) risk. Exercise generally induces positive changes in traditional T2DM risk markers such as lipids, glucose tolerance, and insulin sensitivity; however alterations in concentrations of many circulating cytokines and their respective receptors are also becoming apparent. These cytokines may be early-response health risk factors otherwise overlooked in traditional T2DM risk marker analysis. Plasma levels of two adipocyte-originating cytokines, adiponectin and retinol binding protein 4 (RBP-4), alter following exercise. Adiponectin has anti-inflammatory, anti-atherosclerotic, and anti-insulin resistance roles and its secretion increases with physical activity, whilst elevated RBP-4 leads to increased insulin resistance, and secretion decreases with increasing physical activity; thus these plasma adipokine levels alter favourably following exercise. Although current data are limited, they do suggest that the more intense the exercise, the greater the positive effect on plasma RBP-4 levels, whilst lower intensity aerobic exercise may positively improve adiponectin concentrations. Therefore short-duration, high intensity training may provide a time-efficient alternative to the recommended 150 min moderate aerobic exercise per week in providing positive changes in RBP-4 and other traditional T2DM risk markers and due to increased compliance give greater health benefits over the longer term. PMID:26464853

What is the relationship between exercise and metabolic abnormalities? A review of the metabolic syndrome.

PubMed

Carroll, Sean; Dudfield, Mike

2004-01-01

Prevention of the metabolic syndrome and treatment of its main characteristics are now considered of utmost importance in order to combat the epidemic of type 2 diabetes mellitus and to reduce the increased risk of cardiovascular disease and all-cause mortality. Insulin resistance/hyperinsulinaemia are consistently linked with a clustering of multiple clinical and subclinical metabolic risk factors. It is now widely recognised that obesity (especially abdominal fat accumulation), hyperglycaemia, dyslipidaemia and hypertension are common metabolic traits that, concurrently, constitute the distinctive insulin resistance or metabolic syndrome. Cross-sectional and prospective data provide an emerging picture of associations of both physical activity habits and cardiorespiratory fitness with the metabolic syndrome. The metabolic syndrome, is a disorder that requires aggressive multi-factorial intervention. Recent treatment guidelines have emphasised the clinical utility of diagnosis and an important treatment role for 'therapeutic lifestyle change', incorporating moderate physical activity. Several previous narrative reviews have considered exercise training as an effective treatment for insulin resistance and other components of the syndrome. However, the evidence cited has been less consistent for exercise training effects on several metabolic syndrome variables, unless combined with appropriate dietary modifications to achieve weight loss. Recently published randomised controlled trial data concerning the effects of exercise training on separate metabolic syndrome traits are evaluated within this review. Novel systematic review and meta-analysis evidence is presented indicating that supervised, long-term, moderate to moderately vigorous intensity exercise training, in the absence of therapeutic weight loss, improves the dyslipidaemic profile by raising high density lipoprotein-cholesterol and lowering triglycerides in overweight and obese adults with characteristics of the metabolic syndrome. Lifestyle interventions, including exercise and dietary-induced weight loss may improve insulin resistance and glucose tolerance in obesity states and are highly effective in preventing or delaying the onset of type 2 diabetes in individuals with impaired glucose regulation. Randomised controlled trial evidence also indicates that exercise training decreases blood pressure in overweight/obese individuals with high normal blood pressure and hypertension. These evidence-based findings continue to support recommendations that supervised or partially supervised exercise training is an important initial adjunctive step in the treatment of individuals with the metabolic syndrome. Exercise training should be considered an essential part of 'therapeutic lifestyle change' and may concurrently improve insulin resistance and the entire cluster of metabolic risk factors. Copyright 2004 Adis Data Information BV

The influence of dosing on effect size of exercise therapy for musculoskeletal foot and ankle disorders: a systematic review.

PubMed

Young, Jodi L; Rhon, Daniel I; de Zoete, Rutger M J; Cleland, Joshua A; Snodgrass, Suzanne J

The purpose of this review was to identify doses of exercise therapy associated with greater treatment effect sizes in individuals with common musculoskeletal disorders of the foot and ankle, namely, achilles tendinopathy, ankle sprains and plantar heel pain. AMED, EMBASE and MEDLINE were searched from 2005 to August 2017 for randomized controlled trials related to exercise for these three diagnoses. The Physiotherapy Evidence Database scale was used for methodological quality assessment. Exercise dosing variables and outcome measures related to pain and function were extracted from the studies, and standardized mean differences were calculated for the exercise groups. Fourteen studies met the final inclusion. A majority of the studies showed large effects and two small trends were identified. Patients with plantar heel pain may benefit more from a daily home exercise program than two supervised visits per week (SMD=3.82), but this recommendation is based on weak evidence. In achilles tendinopathy, a relationship was also seen when sets and repetitions of eccentric exercise were performed as tolerated (SMD=1.08 for function, -1.29 for pain). Session duration, frequency, total number of visits, and overall length of care may all be dosing variables with limited value for determining effective exercise prescription. However, the limited number of studies prevents any definitive conclusions. Further investigation is warranted to improve our understanding of the influence exercise dosing has on treatment effect sizes. Future randomized controlled trials comparing specific exercise dose variables should be conducted to clarify the impact of these variables. Copyright © 2017 Associação Brasileira de Pesquisa e Pós-Graduação em Fisioterapia. All rights reserved.

Myocardial hypoperfusion/reperfusion tolerance with exercise training in hypertension.

PubMed

Reger, Patricia O; Barbe, Mary F; Amin, Mamta; Renna, Brian F; Hewston, Leigh Ann; MacDonnell, Scott M; Houser, Steven R; Libonati, Joseph R

2006-02-01

The purpose of this study was to examine whether exercise training, superimposed on compensated-concentric hypertrophy, could increase myocardial hypoperfusion-reperfusion (H/R) tolerance. Female Wistar-Kyoto rats (WKY) and spontaneously hypertensive rats (SHR) (age: 4 mo; N = 40) were placed into a sedentary (SED) or exercise training (TRD) group (treadmill running; 25 m/min, 1 h/day, 5 days/wk for 16 wk). Four groups were studied: WKY-SED (n = 10), WKY-TRD (n = 10), SHR-SED (n = 10), and SHR-TRD (n = 10). Blood pressure and heart rate were determined, and in vitro isolated heart performance was measured with a retrogradely perfused, Langendorff isovolumic preparation. The H/R protocol consisted of a 75% reduction in coronary flow for 17 min followed by 30 min of reperfusion. Although the rate-pressure product was significantly elevated in SHR relative to WKY, training-induced bradycardia reduced the rate-pressure product in SHR-TRD (P < 0.05) without an attenuation in systolic blood pressure. Heart-to-body weight ratio was greater in both groups of SHR vs. WKY-SED (P < 0.001). Absolute and relative myocardial tolerance to H/R was greater in WKY-TRD and both groups of SHR relative to WKY-SED (P < 0.05). Endurance training superimposed on hypertension-induced compensated hypertrophy conferred no further cardioprotection to H/R. Postreperfusion 72-kDa heat shock protein abundance was enhanced in WKY-TRD and both groups of SHR relative to WKY-SED (P < 0.05) and was highly correlated with absolute left ventricular functional recovery during reperfusion (R2= 0.86, P < 0.0001). These data suggest that both compensated hypertrophy associated with short-term hypertension and endurance training individually improved H/R and that increased postreperfusion 72-kDa heat shock protein abundance was, in part, associated with the cardioprotective phenotype observed in this study.

Exercise and bone mass in adults.

PubMed

Guadalupe-Grau, Amelia; Fuentes, Teresa; Guerra, Borja; Calbet, Jose A L

2009-01-01

There is a substantial body of evidence indicating that exercise prior to the pubertal growth spurt stimulates bone growth and skeletal muscle hypertrophy to a greater degree than observed during growth in non-physically active children. Bone mass can be increased by some exercise programmes in adults and the elderly, and attenuate the losses in bone mass associated with aging. This review provides an overview of cross-sectional and longitudinal studies performed to date involving training and bone measurements. Cross-sectional studies show in general that exercise modalities requiring high forces and/or generating high impacts have the greatest osteogenic potential. Several training methods have been used to improve bone mineral density (BMD) and content in prospective studies. Not all exercise modalities have shown positive effects on bone mass. For example, unloaded exercise such as swimming has no impact on bone mass, while walking or running has limited positive effects. It is not clear which training method is superior for bone stimulation in adults, although scientific evidence points to a combination of high-impact (i.e. jumping) and weight-lifting exercises. Exercise involving high impacts, even a relatively small amount, appears to be the most efficient for enhancing bone mass, except in postmenopausal women. Several types of resistance exercise have been tested also with positive results, especially when the intensity of the exercise is high and the speed of movement elevated. A handful of other studies have reported little or no effect on bone density. However, these results may be partially attributable to the study design, intensity and duration of the exercise protocol, and the bone density measurement techniques used. Studies performed in older adults show only mild increases, maintenance or just attenuation of BMD losses in postmenopausal women, but net changes in BMD relative to control subjects who are losing bone mass are beneficial in decreasing fracture risk. Older men have been less studied than women, and although it seems that men may respond better than their female counterparts, the experimental evidence for a dimorphism based on sex in the osteogenic response to exercise in the elderly is weak. A randomized longitudinal study of the effects of exercise on bone mass in elderly men and women is still lacking. It remains to be determined if elderly females need a different exercise protocol compared with men of similar age. Impact and resistance exercise should be advocated for the prevention of osteoporosis. For those with osteoporosis, weight-bearing exercise in general, and resistance exercise in particular, as tolerated, along with exercise targeted to improve balance, mobility and posture, should be recommended to reduce the likelihood of falling and its associated morbidity and mortality. Additional randomized controlled trials are needed to determine the most efficient training loads depending on age, sex, current bone mass and training history for improvement of bone mass.

Sleep Deprivation and Exercise Tolerance.

DTIC Science & Technology

1986-01-01

thermoneutral environment) is alike unchanged by loss of sleep. 5) Seven subjects were allowed to exercise to thermal comfort in a very cold (OC, 2.5...Subjects selected identical work loads for thermal comfort , and became exhausted/miserable after similar period of exposure. Physiologi- cal response and

The Gravity of LBNP Exercise: Lessons Learned from Identical Twins in Bed for 30 Days

NASA Technical Reports Server (NTRS)

Hargens, Alan R.; Groppo, Eli R.; Lee, Stuart M. C.; Watenpaugh, Donald; Schneider, Suzanne; O'Leary, Deborah; Smith, Scott M.; Steinbach, Gregory C.; Tanaka, Kunihiko; Kimura, Shinji;

Modelling decremental ramps using 2- and 3-parameter "critical power" models.

PubMed

Morton, R Hugh; Billat, Veronique

2013-01-01

The "Critical Power" (CP) model of human bioenergetics provides a valuable way to identify both limits of tolerance to exercise and mechanisms that underpin that tolerance. It applies principally to cycling-based exercise, but with suitable adjustments for analogous units it can be applied to other exercise modalities; in particular to incremental ramp exercise. It has not yet been applied to decremental ramps which put heavy early demand on the anaerobic energy supply system. This paper details cycling-based bioenergetics of decremental ramps using 2- and 3-parameter CP models. It derives equations that, for an individual of known CP model parameters, define those combinations of starting intensity and decremental gradient which will or will not lead to exhaustion before ramping to zero; and equations that predict time to exhaustion on those decremental ramps that will. These are further detailed with suitably chosen numerical and graphical illustrations. These equations can be used for parameter estimation from collected data, or to make predictions when parameters are known.

Exercise tolerance during VO2max testing is a multifactorial psychobiological phenomenon.

PubMed

Midgley, Adrian W; Earle, Keith; McNaughton, Lars R; Siegler, Jason C; Clough, Peter; Earle, Fiona

2017-01-01

Fifty-nine men completed a VO 2max test and a questionnaire to establish reasons for test termination, perceived exercise reserve (difference between actual test duration and the duration the individual perceived could have been achieved if continued until physical limitation), and perception of verbal encouragement. Participants gave between 1 and 11 factors as reasons for test termination, including leg fatigue, various perceptions of physical discomfort, safety concerns, and achievement of spontaneously set goals. The two most common main reasons were leg fatigue and breathing discomfort, which were predicted by pre-to-post test changes in pulmonary function (p = 0.038) and explosive leg strength (p = 0.042; R 2  = 0.40). Median (interquartile range) perceived exercise reserve, was 45 (50) s. Two-thirds of participants viewed verbal encouragement positively, whereas one-third had a neutral or negative perception. This study highlights the complexity of exercise tolerance during VO 2max testing and more research should explore these novel findings.

The Nitrate-nitrite-NO pathway and its implications for Heart Failure and Preserved Ejection Fraction

PubMed Central

Chirinos, Julio A.; Zamani, Payman

2016-01-01

The pathogenesis of exercise intolerance in patients with heart failure and preserved ejection fraction (HFpEF) is likely multifactorial. In addition to cardiac abnormalities (diastolic dysfunction, abnormal contractile reserve, chronotropic incompetence), several peripheral abnormalities are likely to be involved. These include abnormal pulsatile hemodynamics, abnormal arterial vasodilatory responses to exercise, and abnormal peripheral O2 delivery, extraction and utilization. The nitrate-nitrite-NO pathway is emerging as a potential target to modify key physiologic abnormalities, including late systolic LV load from arterial wave reflections (which has deleterious short- and long-term consequences for the LV), arterial vasodilatory reserve, muscle O2 delivery, and skeletal muscle mitochondrial function. In a recently completed randomized trial, the administration of a single dose of exogenous inorganic nitrate has been shown exert various salutary arterial hemodynamic effects, ultimately leading to enhanced aerobic capacity in patients with HFpEF. These effects have the potential for both immediate improvements in exercise tolerance and for long-term “disease-modifying” effects. In this review, we provide an overview of key mechanistic contributors to exercise intolerance in HFpEF, and of the potential therapeutic role of drugs that target the nitrate-nitrite-NO pathway. PMID:26792295

Physical activity and training in sarcoidosis: review and experience-based recommendations.

PubMed

Strookappe, Bert; Saketkoo, Lesley Ann; Elfferich, Marjon; Holland, Anne; De Vries, Jolanda; Knevel, Ton; Drent, Marjolein

2016-10-01

Sarcoidosis is a multisystemic inflammatory disorder with a great variety of symptoms, including fatigue, dyspnea, pain, reduced exercise tolerance and muscle strength. Physical training has the potential to improve exercise capacity and muscle strength, and reduce fatigue. The aim of this review and survey was to present information about the role of physical training in sarcoidosis and offer practical guidelines. A systematic literature review guided an international consensus effort among sarcoidosis experts to establish practice-basic recommendations for the implementation of exercise as treatment for patients with various manifestations of sarcoidosis. International sarcoidosis experts suggested considering physical training in symptomatic patients with sarcoidosis. Expert commentary: There is promising evidence of a positive effect of physical training. Recommendations were based on available data and expert consensus. However, the heterogeneity of these patients will require modification and program adjustment of the standard rehabilitation format for e.g. COPD or interstitial lung diseases. An optimal training program (types of exercise, intensities, frequency, duration) still needs to be defined to optimize training adjustments, especially reduction of fatigue. Further randomized controlled trials are needed to consolidate these findings and optimize the comprehensive care of sarcoidosis patients.

Right Ventricular Dysfunction Impairs Effort Tolerance Independent of Left Ventricular Function Among Patients Undergoing Exercise Stress Myocardial Perfusion Imaging.

PubMed

Kim, Jiwon; Di Franco, Antonino; Seoane, Tania; Srinivasan, Aparna; Kampaktsis, Polydoros N; Geevarghese, Alexi; Goldburg, Samantha R; Khan, Saadat A; Szulc, Massimiliano; Ratcliffe, Mark B; Levine, Robert A; Morgan, Ashley E; Maddula, Pooja; Rozenstrauch, Meenakshi; Shah, Tara; Devereux, Richard B; Weinsaft, Jonathan W

2016-11-01

Right ventricular (RV) and left ventricular (LV) function are closely linked due to a variety of factors, including common coronary blood supply. Altered LV perfusion holds the potential to affect the RV, but links between LV ischemia and RV performance, and independent impact of RV dysfunction on effort tolerance, are unknown. The population comprised 2051 patients who underwent exercise stress myocardial perfusion imaging and echo (5.5±7.9 days), among whom 6% had echo-evidenced RV dysfunction. Global summed stress scores were ≈3-fold higher among patients with RV dysfunction, attributable to increments in inducible and fixed LV perfusion defects (all P≤0.001). Regional inferior and lateral wall ischemia was greater among patients with RV dysfunction (both P<0.01), without difference in corresponding anterior defects (P=0.13). In multivariable analysis, inducible inferior and lateral wall perfusion defects increased the likelihood of RV dysfunction (both P<0.05) independent of LV function, fixed perfusion defects, and pulmonary artery pressure. Patients with RV dysfunction demonstrated lesser effort tolerance whether measured by exercise duration (6.7±2.8 versus 7.9±2.9 minutes; P<0.001) or peak treadmill stage (2.6±0.9 versus 3.1±1.0; P<0.001), paralleling results among patients with LV dysfunction (7.0±2.9 versus 8.0±2.9; P<0.001|2.7±1.0 versus 3.1±1.0; P<0.001 respectively). Exercise time decreased stepwise in relation to both RV and LV dysfunction (P<0.001) and was associated with each parameter independent of age or medication regimen. Among patients with known or suspected coronary artery disease, regional LV ischemia involving the inferior and lateral walls confers increased likelihood of RV dysfunction. RV dysfunction impairs exercise tolerance independent of LV dysfunction. © 2016 American Heart Association, Inc.

Incidental lung volume reduction following fulminant pulmonary hemorrhage in a patient with severe emphysema.

PubMed

Hetzel, Juergen; Spengler, Werner; Horger, Marius; Boeckeler, Michael

2015-06-01

Endoscopic lung volume reduction is an emerging technique meant to improve lung function parameters, quality of life, and exercise tolerance in patients with severe lung emphysema. This is the first report of lung volume reduction by autologous blood in a patient with non-bullous lung emphysema. A 74-year-old woman with heterogeneous lung emphysema developed accidentally diffuse lobar bleeding immediately after valve placement. Due to persistent hemorrhage, the valves had to be removed shortly thereafter. Despite extraction of the valves, respiratory function of the patient improved rapidly indicated also by a drop in the COPD assessment test questionnaire, 3 months later. This was consistent with both improvement of lung function tests and six-minute walking test.

Morphological assessment of pancreatic islet hormone content following aerobic exercise training in rats with poorly controlled Type 1 diabetes mellitus.

PubMed

McDonald, Matthew W; Murray, Michael R; Hall, Katharine E; Noble, Earl G; Melling, C W James

2014-01-01

Regular exercise has been shown to improve many complications of Type 1 diabetes mellitus (T1DM) including enhanced glucose tolerance and increased cardiac function. While exercise training has been shown to increase insulin content in pancreatic islets of rats with T1DM, experimental models were severely hyperglycemic and not undergoing insulin treatment. Further, research to date has yet to determine how exercise training alters glucagon content in pancreatic islets. The purpose of the present investigation was to determine the impact of a 10-week aerobic training program on pancreatic islet composition in insulin-treated rats with T1DM. Second, it was determined whether the acute, exercise-mediated reduction in blood glucose experienced in rats with T1DM would become larger in magnitude following aerobic exercise training. Diabetes was induced in male Sprague-Dawley rats by multiple low dose injections of streptozotocin (20mg/kg i.p.) and moderate intensity aerobic exercise training was performed on a motorized treadmill for one hour per day for a total of 10 weeks. Rats with T1DM demonstrated significantly less islet insulin, and significantly more islet glucagon hormone content compared with non-T1DM rats, which did not significantly change following aerobic training. The reduction in blood glucose in response to a single exercise bout was similar across 10 weeks of training. Results also support the view that different subpopulations of islets exist, as small islets (<50 μm diameter) had significantly more insulin and glucagon in rats with and without T1DM.

Interventions for promoting habitual exercise in people living with and beyond cancer.

PubMed

Bourke, Liam; Homer, Kate E; Thaha, Mohamed A; Steed, Liz; Rosario, Derek J; Robb, Karen A; Saxton, John M; Taylor, Stephanie J C

2013-09-24

The beneficial effects of regular exercise for people living with or beyond cancer are becoming apparent. However, how to promote exercise behaviour in sedentary cancer cohorts is not as well understood. A large majority of people living with or recovering from cancer do not meet exercise recommendations. Hence, reviewing the evidence on how to promote and sustain exercise behaviour is important. To assess the effects of interventions to promote exercise behaviour in sedentary people living with and beyond cancer and to address the following questions: Which interventions are most effective in improving aerobic fitness and skeletal muscle strength and endurance? What adverse effects are attributed to different exercise interventions? Which interventions are most effective in improving exercise behaviour amongst patients with different cancers? Which interventions are most likely to promote long-term (12 months or longer) exercise behaviour? What frequency of contact with exercise professionals is associated with increased exercise behaviour? What theoretical basis is most often associated with increased exercise behaviour? What behaviour change techniques are most often associated with increased exercise behaviour? We searched the following electronic databases: Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 8, 2012), MEDLINE, EMBASE, AMED, CINAHL, PsycLIT/PsycINFO, SportDiscus and PEDro from inception to August 2012. We also searched the grey literature, wrote to leading experts in the field, wrote to charities and searched reference lists of other recent systematic reviews. We included only randomised controlled trials (RCTs) that compared an exercise intervention with a usual care approach in sedentary people over the age of 18 with a homogenous primary cancer diagnosis. Two review authors working independently (LB and KH) screened all titles and abstracts to identify studies that might meet the inclusion criteria, or that cannot be safely excluded without assessment of the full text (e.g. when no abstract is available). All eligible papers were formally abstracted by at least two members of the review author team working independently (LB and KH) and using the data collection form. When possible, and if appropriate, we performed a fixed-effect meta-analysis of study outcomes. For continuous outcomes (e.g. cardiorespiratory fitness), we extracted the final value, the standard deviation of the outcome of interest and the number of participants assessed at follow-up in each treatment arm, to estimate standardised mean difference (SMD) between treatment arms. SMD was used, as investigators used heterogeneous methods to assess individual outcomes. If a meta-analysis was not possible or was not appropriate, we synthesised studies as a narrative. Fourteen trials were included in this review, involving a total of 648 participants. Only studies involving breast, prostate or colorectal cancer were identified as eligible. Just six trials incorporated a target level of exercise that could meet current recommendations. Only three trials were identified that attempted to objectively validate independent exercise behaviour with accelerometers or heart rate monitoring. Adherence to exercise interventions, which is crucial for understanding treatment dose, is often poorly reported. It is important to note that the fundamental metrics of exercise behaviour (i.e. frequency, intensity and duration, repetitions, sets and intensity of resistance training), although easy to devise and report, are seldom included in published clinical trials.None of the included trials reported that 75% or greater adherence (the stated primary outcome for this review) of the intervention group met current aerobic exercise recommendations at any given follow-up. Just two trials reported six weeks of resistance exercise behaviour that would meet the guideline recommendations. However, three trials reported adherence of 75% or greater to an aerobic exercise goal that was less than the current guideline recommendation of 150 minutes per week. All three incorporated both supervised and independent exercise components as part of the intervention, and none placed restrictions on the control group in terms of exercise behaviour. These three trials shared programme set goals and the following behaviour change techniques: generalisation of a target behaviour; prompting of self-monitoring of behaviour; and prompting of practise. Despite the uncertainty surrounding adherence in many of the included trials, interventions caused improvements in aerobic exercise tolerance at 8 to 12 weeks (from 7 studies, SMD 0.73, 95% confidence interval (CI) 0.51 to 0.95) in intervention participants compared with controls. At six months, aerobic exercise tolerance was also improved (from 5 studies, SMD 0.70, 95% CI 0.45 to 0.94), but it should be noted that four of the five trials used in this analysis had a high risk of bias, hence caution is warranted in interpretation of results. Attrition over the course of these interventions is typically low (median 6%). Interventions to promote exercise in cancer survivors who report better levels of adherence share some common behaviour change techniques. These involve setting programme goals, prompting practise and self-monitoring and encouraging participants to attempt to generalise behaviours learned in supervised exercise environments to other, non-supervised contexts. However, expecting most sedentary survivors to achieve current guideline recommendations of at least 150 minutes per week of aerobic exercise is likely to be unrealistic. As with all well-designed exercise programmes in any context, prescriptions should be designed around individual capabilities, and frequency, duration and intensity or sets, repetitions, intensity or resistance training should be generated on this basis.

The induction and decay of heat acclimatisation in trained athletes.

PubMed

Armstrong, L E; Maresh, C M

1991-11-01

Heat acclimatisation/acclimation involves a complex of adaptations which includes decreased heart rate, rectal temperature, perceived exertion as well as increased plasma volume and sweat rate. These adaptations serve to reduce physiological strain, improve an athlete's ability to exercise in a hot environment, and reduce the incidence of some forms of heat illness. Few differences exist in the ability of men and women to acclimatise to heat. Typically, older runners do not perform in the heat as well as younger runners, but physical training can negate differences between these groups. Hormonal adaptations (e.g. aldosterone, vasopressin) during heat acclimatisation encourage fluid-electrolyte retention and cardiovascular stability. Athletes with high maximal aerobic power (VO2max) acclimatise to heat faster (and lose adaptations slower when they are inactive in a cool environment) than athletes with low VO2max values. Physical training in a cool environment improves physiological responses to exercise at high ambient temperatures. In attempting to optimise heat acclimatisation, athletes should maintain fluid-electrolyte balance, exercise at intensities greater than 50% VO2max for 10 to 14 days, and avoid factors (e.g. sleep loss, infectious disease) which are known to reduce heat tolerance. Once acclimatisation has been achieved, inactivity results in a decay of favourable adaptations, after only a few days or weeks.

Aerobic and resistance exercise reinforcement and discomfort tolerance predict meeting activity guidelines

USDA-ARS?s Scientific Manuscript database

Background: Understanding individual-differences of those people who do and do not meet physical activity recommendations could inform targets for increasing physical activity. Exercise reinforcement may be one such individual-level determinate, but it is not yet known whether those who meet activi...

Medium-/Long-Term Effects of a Specific Exercise Protocol Combined with Patient Education on Spine Mobility, Chronic Fatigue, Pain, Aerobic Fitness and Level of Disability in Fibromyalgia

PubMed Central

Giannotti, Erika; Koutsikos, Konstantinos; Pigatto, Maurizia; Rampudda, Maria Elisa; Doria, Andrea

2014-01-01

Objective. To propose a rehabilitation protocol able to produce immediate and long-term beneficial effects on level of disability and overall performance in ADLs. Materials and Methods. Forty-one FM patients were randomized to an exercise and educational-behavioral programme group (experimental group, EG = 21) or to a control group (CG = 20). Each subject was evaluated before, at the end (T1), and after 6 months (T6) from the conclusion of the rehabilitation treatment using the Fibromyalgia Impact Questionnaire (FIQ), the visual analogue scale (VAS), the Health Assessment Questionnaire (HAQ), the fatigue severity scale (FSS), the 6-minute walking test (6MWT), tender points count (TPC), and spinal active range of motion. The exercise protocol included 20 sessions consisting in self-awareness, stretching, strengthening, spine flexibility, and aerobic exercises, which patients were subsequently educated to perform at home. Results. The two groups were comparable at baseline. At T1, the EG showed a positive trend in FIQ, VAS, HAQ, and FSS scales and significant improvement in 6MWT and in most spinal active range of motion measurements (P between 0.001 and 0.04). The positive results were maintained at the follow-up. Conclusion. The proposed programme was well tolerated and produced immediate and medium-term beneficial effects improving function and strain endurance. This trial is registered with DRKS00005071 on DRKS. PMID:24616894

Effects of supervised exercise and dietary nitrate in older adults with controlled hypertension and/or heart failure with preserved ejection fraction.

PubMed

Shaltout, Hossam A; Eggebeen, Joel; Marsh, Anthony P; Brubaker, Peter H; Laurienti, Paul J; Burdette, Jonathan H; Basu, Swati; Morgan, Ashley; Dos Santos, Patricia C; Norris, James L; Morgan, Timothy M; Miller, Gary D; Rejeski, W Jack; Hawfield, Amret T; Diz, Debra I; Becton, J Thomas; Kim-Shapiro, Daniel B; Kitzman, Dalane W

2017-09-30

Aerobic exercise training is an effective therapy to improve peak aerobic power (peak VO 2 ) in individuals with hypertension (HTN, AHA/ACC class A) and heart failure patients with preserved ejection fraction (HFpEF). High nitrate containing beetroot juice (BRJ) also improves sub-maximal endurance and decreases blood pressure in both HTN and HFpEF. We hypothesized that combining an aerobic exercise and dietary nitrate intervention would result in additive or even synergistic positive effects on exercise tolerance and blood pressure in HTN or HFpEF. We report results from two pilot studies examining the effects of supervised aerobic exercise combined with dietary nitrate in patients with controlled HTN (n = 26, average age 65 ± 5 years) and in patients with HFpEF (n = 20, average age 69 ± 7 years). All patients underwent an aerobic exercise training regimen; half were randomly assigned to consume a high nitrate-containing beet juice beverage (BRJ containing 6.1 mmol nitrate for the HFpEF study consumed three times a week and 8 mmol nitrate for the HTN study consumed daily) while the other half consumed a beet juice beverage with the nitrate removed (placebo). The main result was that there was no added benefit observed for any outcomes when comparing BRJ to placebo in either HTN or HFpEF patients undergoing exercise training (p ≥ 0.14). There were within-group benefits. In the pilot study in patients with HFpEF, aerobic endurance (primary outcome), defined as the exercise time to volitional exhaustion during submaximal cycling at 75% of maximal power output, improved during exercise training within each group from baseline to end of study, 369 ± 149 s vs 520 ± 257 s (p = 0.04) for the placebo group and 384 ± 129 s vs 483 ± 258 s for the BRJ group (p = 0.15). Resting systolic blood pressure in patients with HFpEF also improved during exercise training in both groups, 136 ± 16 mm Hg vs 122 ± 3 mm Hg for the placebo group (p < 0.05) and 132 ± 12 mm Hg vs 119 ± 9 mm Hg for the BRJ group (p < 0.05). In the HTN pilot study, during a treadmill graded exercise test, peak oxygen consumption (primary outcome) did not change significantly, but time to exhaustion (also a primary outcome) improved in both groups, 504 ± 32 s vs 601 ± 38 s (p < 0.05) for the placebo group and 690 ± 38 s vs 772 ± 95 s for the BRJ group (p < 0.05) which was associated with a reduction in supine resting systolic blood pressure in BRJ group. Arterial compliance also improved during aerobic exercise training in both the HFpEF and the HTN patients for both BRJ and placebo groups. Future work is needed to determine if larger nitrate doses would provide an added benefit to supervised aerobic exercise in HTN and HFpEF patients. Copyright © 2017 Elsevier Inc. All rights reserved.

Reduction in reactive oxygen species production by mitochondria from elderly subjects with normal and impaired glucose tolerance.

PubMed

Ghosh, Sangeeta; Lertwattanarak, Raweewan; Lefort, Natalie; Molina-Carrion, Marjorie; Joya-Galeana, Joaquin; Bowen, Benjamin P; Garduno-Garcia, Jose de Jesus; Abdul-Ghani, Muhammad; Richardson, Arlan; DeFronzo, Ralph A; Mandarino, Lawrence; Van Remmen, Holly; Musi, Nicolas

2011-08-01

Aging increases the risk of developing impaired glucose tolerance (IGT) and type 2 diabetes. It has been proposed that increased reactive oxygen species (ROS) generation by dysfunctional mitochondria could play a role in the pathogenesis of these metabolic abnormalities. We examined whether aging per se (in subjects with normal glucose tolerance [NGT]) impairs mitochondrial function and how this relates to ROS generation, whether older subjects with IGT have a further worsening of mitochondrial function (lower ATP production and elevated ROS generation), and whether exercise reverses age-related changes in mitochondrial function. Mitochondrial ATP and ROS production were measured in muscle from younger individuals with NGT, older individuals with NGT, and older individuals with IGT. Measurements were performed before and after 16 weeks of aerobic exercise. ATP synthesis was lower in older subjects with NGT and older subjects with IGT versus younger subjects. Notably, mitochondria from older subjects (with NGT and IGT) displayed reduced ROS production versus the younger group. ATP and ROS production were similar between older groups. Exercise increased ATP synthesis in the three groups. Mitochondrial ROS production also increased after training. Proteomic analysis revealed downregulation of several electron transport chain proteins with aging, and this was reversed by exercise. Old mitochondria from subjects with NGT and IGT display mitochondrial dysfunction as manifested by reduced ATP production but not with respect to increased ROS production. When adjusted to age, the development of IGT in elderly individuals does not involve changes in mitochondrial ATP and ROS production. Lastly, exercise reverses the mitochondrial phenotype (proteome and function) of old mitochondria.

Intensive Exercise Training During Bed Rest Attenuates Deconditioning

NASA Technical Reports Server (NTRS)

Greenleaf, John E.

1997-01-01

Intensive exercise training during bed rest attenuates deconditioning. Med. Sci. Sports Exerc., Vol. 29, No. 2, pp. 207-215, 1997. A 30-d 6 deg head-down bed rest project was conducted to evaluate variable high-intensity, short-duration, isotonic cycle ergometer exercise (ITE) training and high-intensity intermittent resistive isokinetic exercise (IKE) training regimens designed to maintain peak VO2 and muscle mass, strength, and endurance at ambulatory control levels throughout prolonged bed rest. Other elements of the deconditioning (adaptive) syndrome, such as proprioception, psychological performance, hypovolemia, water balance, body composition, and orthostatic tolerance, were also measured. Major findings are summarized in this paper. Compared with response during bed rest of the no exercise (NOE) control group: the ITE training regimen (a) maintained work capacity (peak VO2), (b) maintained plasma and red cell volumes, (c) induced positive body water balance, (d) decreased quality of sleep and mental concentration, and (e) had no effect on the decrease in orthostatic tolerance; the IKE training regimen (f) attenuated the decrease in peak VO2 by 50%, (g) attenuated loss of red cell volume by 40% but had no effect on loss of plasma volume, (b) induced positive body water balance, (i) had no adverse effect on quality of sleep or concentration, and 0) had no effect on the decrease in orthostatic tolerance. These findings suggest that various elements of the deconditioning syndrome can be manipulated by duration and intensity of ITE or IKE training regimens and that several different training protocols will be required to maintain or restore physiological and psychological performance of individuals confined to prolonged bed rest.

Exercise Training During Bed Rest Attenuates Deconditioning

NASA Technical Reports Server (NTRS)

Greenleaf, J. E.; Hargens, Alan R. (Technical Monitor)

1995-01-01

A 30-day 6 deg. head-down bed rest study was conducted to evaluate high-intensity, short-duration, alternating isotonic cycle ergometer exercise (ITE) training and high-intensity intermittent isokinetic exercise (IKE) training regiments designed to maintain peak VO2 and muscle mass, strength, and endurance at ambulatory control levels throughout prolonged bed rest. Other elements of the deconditioning (acclimation) syndrome, such as proprioception, psychological performance, hypovolemia, water balance, body composition, and orthostatic tolerance, were also measured. Compared with response during bed rest of the no exercise (NOE) control group: the ITE training regimen (a) maintained work capacity (peak VO2), (b) maintained plasma and red cell volume, (c) induced positive body water balance, (d) decreased quality of sleep and mental concentration, and (e) had no effect on the decrease in orthostatic tolerance; the IKE training regimen (a) attenuated the decrease in peak VO2 by 50%, (b) attenuated loss of red cell volume by 40%, but had no effect on loss of plasma volume, (c) induced positive body water balance, (d) had no adverse effect on quality of sleep or concentration, and (e) had no effect on the decrease in orthostatic tolerance. These findings suggest that various elements of the deconditioning syndrome can be manipulated by duration and intensity of ITE or IKE training regiments, and that several different training protocols will be required to maintain or restore physiological and psychological performance of individuals confined to prolonged bed rest.

Lower dipeptidyl peptidase-4 following exercise training plus weight loss is related to increased insulin sensitivity in adults with metabolic syndrome.

PubMed

Malin, Steven K; Huang, Hazel; Mulya, Anny; Kashyap, Sangeeta R; Kirwan, John P

2013-09-01

Dipeptidyl peptidase-4 (DPP-4) is a circulating glycoprotein that impairs insulin-stimulated glucose uptake and is linked to obesity and metabolic syndrome. However, the effect of exercise on plasma DPP-4 in adults with metabolic syndrome is unknown. Therefore, we determined the effect of exercise on DPP-4 and its role in explaining exercise-induced improvements in insulin sensitivity. Fourteen obese adults (67.9±1.2 years, BMI: 34.2±1.1kg/m(2)) with metabolic syndrome (ATP III criteria) underwent a 12-week supervised exercise intervention (60min/day for 5 days/week at ∼85% HRmax). Plasma DPP-4 was analyzed using an enzyme-linked immunosorbent assay. Insulin sensitivity was measured using the euglycemic-hyperinsulinemic clamp (40mU/m(2)/min) and estimated by HOMA-IR. Visceral fat (computerized tomography), 2-h glucose levels (75g oral glucose tolerance), and basal fat oxidation as well as aerobic fitness (indirect calorimetry) were also determined before and after exercise. The intervention reduced visceral fat, lowered blood pressure, glucose and lipids, and increased aerobic fitness (P<0.05). Exercise improved clamp-derived insulin sensitivity by 75% (P<0.001) and decreased HOMA-IR by 15% (P<0.05). Training decreased plasma DPP-4 by 10% (421.8±30.1 vs. 378.3±32.5ng/ml; P<0.04), and the decrease in DPP-4 was associated with clamp-derived insulin sensitivity (r=-0.59; P<0.04), HOMA-IR (r=0.59; P<0.04) and fat oxidation (r=-0.54; P<0.05). Increased fat oxidation also correlated with lower 2-h glucose levels (r=-0.64; P<0.02). Exercise training reduces plasma DPP-4, which may be linked to elevated insulin sensitivity and fat oxidation. Maintaining low plasma DPP-4 concentrations is a potential mechanism whereby exercise plus weight loss prevents/delays the onset of type 2 diabetes in adults with metabolic syndrome. Copyright © 2013 Elsevier Inc. All rights reserved.

Prospective evaluation of a 12-week walking exercise program and its effect on fatigue in prostate cancer patients undergoing radical external beam radiotherapy.

PubMed

Truong, Pauline T; Gaul, Catherine A; McDonald, Rachel E; Petersen, Ross B; Jones, Stuart O; Alexander, Abraham S; Lim, Jan T W; Ludgate, Charles

2011-08-01

To evaluate tolerability and compliance to a walking exercise program and its effect on fatigue during and after radical external beam radiation therapy (EBRT) for prostate cancer. A total of 50 subjects with prostate cancer undergoing EBRT over 6 to 8 weeks were prospectively accrued to an exercise intervention group, matched for age and clinical characteristics to 30 subjects in a historical control group who underwent EBRT with no specific exercise intervention. Starting 1 week before EBRT, exercise participants performed moderate-intensity walking targeting 60% to 70% age-predicted maximum heart rate, at least 20 min/d, 3 d/wk over 12 weeks. The Brief Fatigue Inventory was administered at baseline, mid-EBRT (week 3-4), end-EBRT (week 6-8), and 6 months post-EBRT. Of 50, 42 (84%) of exercise participants completed the walking program. There were no cardiovascular complications, musculoskeletal injuries, or other adverse events. A total of 89% subjects reported "Good-Excellent" satisfaction during and up to 6 months post-EBRT. Fatigue in control subjects escalated from baseline to end-EBRT, remaining high at 6 months post-EBRT (P[r] = 0.03). In contrast, mean total fatigue scores in exercise subjects were stable from baseline up to 6 months post-EBRT (P = 0.52). Trends for higher fatigue interference with quality of life were observed in the control group as compared with the exercise group. Moderate-intensity walking exercise during radical EBRT is safe and feasible. The high convenience and satisfaction ratings, in conjunction with the observed fatigue trends, indicate that this activity has the potential to attenuate fatigue and improve quality of life for patients with localized prostate cancer undergoing curative therapy.

Adherence to prescribed exercise and diet regimens two months post-cardiac rehabilitation.

PubMed

Scotto, Carrie J; Waechter, Donna J; Rosneck, James

2011-01-01

Adherence to diet and exercise regimens significantly limits morbidity and mortality for cardiac patients. Research at six and 12 months post CR program indicates that healthy behaviours learned in CR are not sustained. However, little is known about the extent of adherence in the immediate program completion period. To determine CR participants' knowledge of their diet and exercise prescription and the degree of adherence two months after completing CR, and to examine demographic and clinical variables to identify relationships to adherence behaviours. Participants (n = 174) were recruited from Phase II CR over a one-year period. The Diet Habit Survey (DHS) and Duke Activity Status Index (DASI) scores were administered at admission, discharge, and two months post discharge. Structured telephone interviews were conducted to evaluate adherence behaviours. Spearman correlation was used to determine relationships between demographic and clinical variables and adherence behaviours. Repeated measures ANOVA showed DHS and DASI scores were significantly higher at discharge (p < 0.001) without significant drift at two months post program (p < 0.09). These scores were in contrast with low self-report of knowledge of dietary and exercise recommendations and adherence to dietary and exercise instructions. Lower knowledge about diet and exercise were correlated with employment (diet, p < 0.001; exercise, p < 0.025). Decreased dietary adherence was correlated with BMI (p < 0.005). Exercise adherence was correlated with gender (p < 0.021) and marital status (p < 0.042). Although CR participants gain and retain knowledge about necessary dietary changes and improve their exercise activity tolerance during CR, most fail to translate the information into health promoting behaviour changes beginning in the immediate discharge period. Research to identify methods that transform knowledge into lasting behaviour change post CR is needed.

Endurance exercise training effects on body fatness, VO2max, HDL-C subfractions, and glucose tolerance are influenced by a PLIN haplotype in older Caucasians.

PubMed

Jenkins, Nathan T; McKenzie, Jennifer A; Damcott, Coleen M; Witkowski, Sarah; Hagberg, James M

2010-03-01

Perilipins are lipid droplet-coating proteins that regulate intracellular lipolysis in adipocytes. A haplotype of two perilipin gene (PLIN) single nucleotide polymorphisms, 13041A>G and 14995A>T, has been previously associated with obesity risk. Furthermore, the available data indicate that this association may be modified by sex. We hypothesized that this haplotype would associate with body fatness, aerobic fitness, and a number of cardiovascular (CV) risk factor phenotypes before and after a 6-mo endurance exercise training program in sedentary older Caucasians. The major haplotype group (13041A/14995A; n = 57) had significantly lower body mass index (BMI) and body fatness compared with noncarriers of the AA haplotype (n = 44) before the training intervention. Training improved body composition in both groups, but fatness remained higher in noncarriers than AA carriers after training. This fat retention in noncarriers blunted their maximal oxygen uptake (Vo(2 max)) adaptation to training. Female noncarriers had substantially higher concentrations of several conventionally and NMR-measured HDL-C subfractions than male noncarriers before and after training, but only minimal differences were found between the sexes in the AA haplotype group. Haplotype group differences in baseline and after-training responses to an oral glucose tolerance test (OGTT) also differed by sex, as noncarrier men had the highest baseline area under the insulin curve (insulin AUC), but were the only group to significantly improve insulin AUC with training. The insulin sensitivity index and plasma glucose responses to the OGTT were more favorable in AA carriers than noncarriers before and after training. Overall, our findings suggest that PLIN variation explains some of the interindividual differences in the response of obesity and CV phenotypes to exercise training. Furthermore, these data contribute to the growing understanding of PLIN as a candidate gene for human obesity and the cardiometabolic consequences of excess adiposity.

Free fatty acid-induced hepatic insulin resistance is attenuated following lifestyle intervention in obese individuals with impaired glucose tolerance.

PubMed

Haus, Jacob M; Solomon, Thomas P J; Marchetti, Christine M; Edmison, John M; González, Frank; Kirwan, John P

2010-01-01

The objective of the study was to examine the effects of an exercise/diet lifestyle intervention on free fatty acid (FFA)-induced hepatic insulin resistance in obese humans. Obese men and women (n = 23) with impaired glucose tolerance were randomly assigned to either exercise training with a eucaloric (EU; approximately 1800 kcal; n = 11) or hypocaloric (HYPO; approximately 1300 kcal; n = 12) diet for 12 wk. Hepatic glucose production (HGP; milligrams per kilogram fat-free mass(-1) per minute(-1)) and hepatic insulin resistance were determined using a two-stage sequential hyperinsulinemic (40 mU/m(2) . min(-1)) euglycemic (5.0 mm) clamp with [3-(3)H]glucose. Measures were obtained at basal, during insulin infusion (INS; 120 min), and insulin plus intralipid/heparin infusion (INS/FFA; 300 min). At baseline, basal HGP was similar between groups; hyperinsulinemia alone did not completely suppress HGP, whereas INS/FFA exhibited less suppression than INS (EU, 4.6 +/- 0.8, 2.0 +/- 0.5, and 2.6 +/- 0.4; HYPO, 3.8 +/- 0.5, 1.2 +/- 0.3, and 2.3 +/- 0.4, respectively). After the intervention the HYPO group lost more body weight (P < 0.05) and fat mass (P < 0.05). However, both lifestyle interventions reduced hepatic insulin resistance during basal (P = 0.005) and INS (P = 0.001) conditions, and insulin-mediated suppression of HGP during INS was equally improved in both groups (EU: -42 +/- 22%; HYPO: -50 +/- 20%, before vs. after, P = 0.02). In contrast, the ability of insulin to overcome FFA-induced hepatic insulin resistance and HGP was improved only in the HYPO group (EU: -15 +/- 24% vs. HYPO: -58 +/- 19%, P = 0.02). Both lifestyle interventions are effective in reducing hepatic insulin resistance under basal and hyperinsulinemic conditions. However, the reversal of FFA-induced hepatic insulin resistance is best achieved with a combined exercise/caloric-restriction intervention.

A randomized, double-blind, placebo-controlled, phase II clinical trial to investigate the efficacy and safety of oral DA-1229 in patients with type 2 diabetes mellitus who have inadequate glycaemic control with diet and exercise.

PubMed

Jung, Chang Hee; Park, Cheol-Young; Ahn, Kyu-Joeng; Kim, Nan-Hee; Jang, Hak-Chul; Lee, Moon-Kyu; Park, Joong-Yeol; Chung, Choon-Hee; Min, Kyung-Wan; Sung, Yeon-Ah; Park, Jeong-Hyun; Kim, Sung Jin; Lee, Hyo Jung; Park, Sung-Woo

2015-03-01

DA-1229 is a novel, potent and selective dipeptidyl peptidase-4 (DPP-IV) inhibitor that is orally bioavailable. We aimed to evaluate the optimal dose, efficacy and safety of DA-1229, in Korean subjects with type 2 diabetes mellitus suboptimally controlled with diet and exercise. We enrolled 158 patients (mean age, 53 years and a mean BMI, 25.6 kg/m(2) ). The mean baseline fasting plasma glucose level, HbA1c and duration of diabetes were 8.28 mmol/L, 7.6% (60 mmol/mol) and 3.9 years, respectively. After 2 or 6 weeks of an exercise and diet program followed by 2 weeks of a placebo period, the subjects were randomized into one of four groups for a 12-week active treatment period: placebo, 2.5, 5 or 10 mg of DA-1229. All three doses of DA-1229 significantly reduced HbA1c from baseline compared to the placebo group (-0.09 in the placebo group vs. -0.56, -0.66 and -0.61% in 2.5, 5 and 10-mg groups, respectively) but without any significant differences between the doses. Insulin secretory function, as assessed by homeostasis model assessment β-cell, the insulinogenic index, 2-h oral glucose tolerance test (OGTT) C-peptide and post-OGTT C-peptide area under the curve (AUC)0-2h, significantly improved with DA-1229 treatment. The incidence of adverse events was similar between the treatment groups and DA-1229 did not affect body weight or induce hypoglycaemic events. DA-1229 monotherapy (5 mg for 12 weeks) improved HbA1c, fasting plasma glucose level, OGTT results and β-cell function. This drug was well tolerated in Korean subjects with type 2 diabetes mellitus. © 2014 The Authors. Diabetes/Metabolism Research and Reviews published by John Wiley & Sons, Ltd.

Endurance exercise training effects on body fatness, V̇o2max, HDL-C subfractions, and glucose tolerance are influenced by a PLIN haplotype in older Caucasians

PubMed Central

Jenkins, Nathan T.; McKenzie, Jennifer A.; Damcott, Coleen M.; Witkowski, Sarah

2010-01-01

Perilipins are lipid droplet-coating proteins that regulate intracellular lipolysis in adipocytes. A haplotype of two perilipin gene (PLIN) single nucleotide polymorphisms, 13041A>G and 14995A>T, has been previously associated with obesity risk. Furthermore, the available data indicate that this association may be modified by sex. We hypothesized that this haplotype would associate with body fatness, aerobic fitness, and a number of cardiovascular (CV) risk factor phenotypes before and after a 6-mo endurance exercise training program in sedentary older Caucasians. The major haplotype group (13041A/14995A; n = 57) had significantly lower body mass index (BMI) and body fatness compared with noncarriers of the AA haplotype (n = 44) before the training intervention. Training improved body composition in both groups, but fatness remained higher in noncarriers than AA carriers after training. This fat retention in noncarriers blunted their maximal oxygen uptake (V̇o2max) adaptation to training. Female noncarriers had substantially higher concentrations of several conventionally and NMR-measured HDL-C subfractions than male noncarriers before and after training, but only minimal differences were found between the sexes in the AA haplotype group. Haplotype group differences in baseline and after-training responses to an oral glucose tolerance test (OGTT) also differed by sex, as noncarrier men had the highest baseline area under the insulin curve (insulin AUC), but were the only group to significantly improve insulin AUC with training. The insulin sensitivity index and plasma glucose responses to the OGTT were more favorable in AA carriers than noncarriers before and after training. Overall, our findings suggest that PLIN variation explains some of the interindividual differences in the response of obesity and CV phenotypes to exercise training. Furthermore, these data contribute to the growing understanding of PLIN as a candidate gene for human obesity and the cardiometabolic consequences of excess adiposity. PMID:19850727

Safety and tolerability of omecamtiv mecarbil during exercise in patients with ischemic cardiomyopathy and angina.

PubMed

Greenberg, Barry H; Chou, Willis; Saikali, Khalil G; Escandón, Rafael; Lee, Jacqueline H; Chen, Michael M; Treshkur, Tatyana; Megreladze, Irakli; Wasserman, Scott M; Eisenberg, Paul; Malik, Fady I; Wolff, Andrew A; Shaburishvili, Tamaz

2015-01-01

The goal of this study was to assess the safety and tolerability of omecamtiv mecarbil treatment during symptom-limited exercise in patients with ischemic cardiomyopathy and angina. These patients may have increased vulnerability to prolongation of the systolic ejection time. Omecamtiv mecarbil is a selective cardiac myosin activator that augments cardiac contractility in patients with systolic heart failure through a dose-dependent increase in systolic ejection time. In this double-blind, placebo-controlled study, patients with chronic heart failure were randomized 2:1 to receive omecamtiv mecarbil or placebo in 2 sequential cohorts of escalating doses designed to achieve plasma concentrations previously shown to increase systolic function. Patients underwent 2 symptom-limited exercise treadmill tests (ETTs) at baseline (ETT1 and ETT2) and again before the end of a 20-h infusion of omecamtiv mecarbil (ETT3). The primary pre-defined safety endpoint (i.e., the proportion of patients who stopped ETT3 because of angina at a stage earlier than baseline) was observed in 1 patient receiving placebo and none receiving omecamtiv mecarbil. No dose-dependent differences emerged in the proportion of patients stopping ETT3 for any reason or in the pattern of adverse events. Doses of omecamtiv mecarbil producing plasma concentrations previously shown to increase systolic function were well tolerated during exercise in these study patients with ischemic cardiomyopathy and angina. There was no indication that treatment increased the likelihood of myocardial ischemia in this high-risk population. (Pharmacokinetics [PK] and Tolerability of Intravenous [IV] and Oral CK-1827452 in Patients With Ischemic Cardiomyopathy and Angina; NCT00682565). Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Development of a neuromuscular electrical stimulation protocol for sprint training.

PubMed

Russ, David W; Clark, Brian C; Krause, Jodi; Hagerman, Fredrick C

2012-09-01

Sprint training is associated with several beneficial adaptations in skeletal muscle, including an enhancement of sarcoplasmic reticulum (SR) Ca(2+) release. Unfortunately, several patient populations (e.g., the elderly, those with cardiac dysfunction) that might derive great benefit from sprint exercise are unlikely to tolerate it. The purpose of this report was to describe the development of a tolerable neuromuscular electrical stimulation (NMES) protocol that induces skeletal muscle adaptations similar to those observed with sprint training. Our NMES protocol was modeled after a published sprint exercise protocol and used a novel electrode configuration and stimulation sequence to provide adequate training stimulus while maintaining subject tolerance. Nine young, healthy subjects (four men) began and completed the training protocol of the knee extensor muscles. All subjects completed the protocol, with ratings of discomfort far less than those reported in studies of traditional NMES. Training induced significant increases in SR Ca(2+) release and citrate synthase activity (~16% and 32%, respectively), but SR Ca(2+) uptake did not change. The percentage of myosin heavy chain IIx isoform was decreased significantly after training. At the whole muscle level, neither central activation nor maximum voluntary isometric contraction force were significantly altered, although isometric force did exhibit a trend toward an increase (~3%, P = 0.055). Surprisingly, the NMES training produced a significant increase in muscle cross-sectional area (~3%, P = 0.04). It seems that an appropriately designed NMES protocol can mimic many of the benefits of sprint exercise training, with a low overall time commitment and training volume. These findings suggest that NMES has the potential to bring the benefits of sprint exercise to individuals who are unable to tolerate traditional sprint training.

High-intensity interval training without weight loss improves exercise but not basal or insulin-induced metabolism in overweight/obese African American women.

PubMed

Arad, Avigdor D; DiMenna, Fred J; Thomas, Naketa; Tamis-Holland, Jacqueline; Weil, Richard; Geliebter, Allan; Albu, Jeanine B

2015-08-15

The purpose of this randomized controlled clinical trial was to determine the effect of a 14-week high-intensity interval training (HIIT) intervention with weight stability on metabolic flexibility, insulin sensitivity, and cardiorespiratory fitness in sedentary, premenopausal, nondiabetic, overweight/obese African American women. Twenty-eight subjects were allocated to one of two groups: HIIT, which performed three sessions per week of four high-intensity cycling intervals, or a control group (CON), which maintained their normal level of physical activity. Diet was controlled for all subjects to ensure weight stability. Pre- and postintervention (pre/post), subjects completed an incremental cycling test to limit of tolerance and, following a 10-day high-fat controlled feeding period, a euglycemic-hyperinsulinemic clamp to determine insulin sensitivity and substrate oxidation. Nine members of HIIT (age, 29 ± 4 yr; body mass, 90.1 ± 13.8 kg) and eleven members of CON (age, 30 ± 7 yr; body mass, 85.5 ± 10.7 kg) completed the study. HIIT experienced an increased limit of tolerance (post, 1,124 ± 202 s; pre, 987 ± 146 s; P < 0.05), gas exchange threshold (post, 1.29 ± 0.34 liters/min; pre, 0.97 ± 0.23 liters/min; P < 0.05), and fat oxidation at the same absolute submaximal work rate compared with CON (P < 0.05 for group-by-time interaction in all cases). However, changes in peak oxygen consumption (V̇o2peak), insulin sensitivity, free fatty acid suppression during insulin stimulation, and metabolic flexibility were not different in HIIT compared with CON. High-intensity interval training with weight stability increased exercise fat oxidation and tolerance in subjects at risk for diabetic progression, but did not improve insulin sensitivity or fat oxidation in the postabsorptive or insulin-stimulated state. Copyright © 2015 the American Physiological Society.

Postnatal PPARdelta activation and myostatin inhibition exert distinct yet complimentary effects on the metabolic profile of obese insulin-resistant mice.

PubMed

Bernardo, Barbara L; Wachtmann, Timothy S; Cosgrove, Patricia G; Kuhn, Max; Opsahl, Alan C; Judkins, Kyle M; Freeman, Thomas B; Hadcock, John R; LeBrasseur, Nathan K

2010-06-25

Interventions for T2DM have in part aimed to mimic exercise. Here, we have compared the independent and combined effects of a PPARdelta agonist and endurance training mimetic (GW501516) and a myostatin antibody and resistance training mimetic (PF-879) on metabolic and performance outcomes in obese insulin resistant mice. Male ob/ob mice were treated for 6 weeks with vehicle, GW501516, PF-879, or GW501516 in combination with PF-879. The effects of the interventions on body composition, glucose homeostasis, glucose tolerance, energy expenditure, exercise capacity and metabolic gene expression were compared at the end of study. GW501516 attenuated body weight and fat mass accumulation and increased the expression of genes of oxidative metabolism. In contrast, PF-879 increased body weight by driving muscle growth and altered the expression of genes involved in insulin signaling and glucose metabolism. Despite their differences, both interventions alone improved glucose homeostasis. Moreover, GW501516 more effectively improved serum lipids, and PF-879 uniquely increased energy expenditure, exercise capacity and adiponectin levels. When combined the robust effects of GW501516 and/or PF-879 on body weight, adiposity, muscle mass, glycemia, serum lipids, energy expenditure and exercise capacity were highly conserved. The data, for the first time, demonstrate postnatal inhibition of myostatin not only promotes gains in muscle mass similar to resistance training,but improves metabolic homeostasis. In several instances, these effects were either distinct from or complimentary to those of GW501516. The data further suggest that strategies to increase muscle mass, and not necessarily oxidative capacity, may effectively counter insulin resistance and T2DM.

Comparison of Combined Aerobic and High-Force Eccentric Resistance Exercise With Aerobic Exercise Only for People With Type 2 Diabetes Mellitus

PubMed Central

Marcus, Robin L; Smith, Sheldon; Morrell, Glen; Addison, Odessa; Dibble, Leland E; Wahoff-Stice, Donna; LaStayo, Paul C

2008-01-01

Background and Purpose: The purpose of this study was to compare the outcomes between a diabetes exercise training program using combined aerobic and high-force eccentric resistance exercise and a program of aerobic exercise only. Subjects and Methods: Fifteen participants with type 2 diabetes mellitus (T2DM) participated in a 16-week supervised exercise training program: 7 (mean age=50.7 years, SD=6.9) in a combined aerobic and eccentric resistance exercise program (AE/RE group) and 8 (mean age=58.5 years, SD=6.2) in a program of aerobic exercise only (AE group). Outcome measures included thigh lean tissue and intramuscular fat (IMF), glycosylated hemoglobin, body mass index (BMI), and 6-minute walk distance. Results: Both groups experienced decreases in mean glycosylated hemoglobin after training (AE/RE group: −0.59% [95% confidence interval (CI)=−1.5 to 0.28]; AE group: −0.31% [95% CI=−0.60 to −0.03]), with no significant between-group differences. There was an interaction between group and time with respect to change in thigh lean tissue cross-sectional area, with the AE/RE group gaining more lean tissue (AE/RE group: 15.1 cm2 [95% CI=7.6 to 22.5]; AE group: −5.6 cm2 [95% CI=−10.4 to 0.76]). Both groups experienced decreases in mean thigh IMF cross-sectional area (AE/RE group: −1.2 cm2 [95% CI=−2.6 to 0.26]; AE group: −2.2 cm2 [95% CI=−3.5 to −0.84]) and increases in 6-minute walk distance (AE/RE group: 45.5 m [95% CI=7.5 to 83.6]; AE group: 29.9 m [95% CI=−7.7 to 67.5]) after training, with no between-group differences. There was an interaction between group and time with respect to change in BMI, with the AE/RE group experiencing a greater decrease in BMI. Discussion and Conclusion: Significant improvements in long-term glycemic control, thigh composition, and physical performance were demonstrated in both groups after participating in a 16-week exercise program. Subjects in the AE/RE group demonstrated additional improvements in thigh lean tissue and BMI. Improvements in thigh lean tissue may be important in this population as a means to increase resting metabolic rate, protein reserve, exercise tolerance, and functional mobility. PMID:18801851

Effects of crocin and voluntary exercise, alone or combined, on heart VEGF-A and HOMA-IR of HFD/STZ induced type 2 diabetic rats.

PubMed

Ghorbanzadeh, V; Mohammadi, M; Dariushnejad, H; Chodari, L; Mohaddes, G

2016-10-01

Hyperglycemia is the main risk factor for microvascular complications in type 2 diabetes. Crocin and voluntary exercise have anti-hyperglycemic effects in diabetes. In this research, we evaluated the effects of crocin and voluntary exercise alone or combined on glycemia control and heart level of VEGF-A. Animals were divided into eight groups as: control (con), diabetes (Dia), crocin (Cro), voluntary exercise (Exe), crocin and voluntary exercise (Cro-Exe), diabetic-crocin (Dia-Cro), diabetic-voluntary exercise (Dia-Exe), diabetic-crocin-voluntary exercise (Dia-Cro-Exe). Type 2 diabetes was induced by a high-fat diet (4 weeks) and injection of streptozotocin (STZ) (i.p, 35 mg/kg). Animals received oral administration of crocin (50 mg/kg) or performed voluntary exercise alone or together for 8 weeks. Oral glucose tolerance test (OGTT) was performed on overnight fasted control, diabetic and treated rats after 8 weeks of treatment. Then, serum insulin and heart VEGF-A protein levels were measured. Crocin combined with voluntary exercise significantly decreased blood glucose levels (p < 0.001) and insulin resistance (HOMA-IR) (p < 0.001) compared to diabetic group. VEGF-A level was significantly (p < 0.01) lower in Dia group compared to control group. The combination of crocin and voluntary exercise significantly enhanced VEGF-A protein levels in Dia-Cro-Exe and Cro-Exe group compared to diabetic and control groups, respectively; p < 0.001 and p < 0.05. Crocin combined with voluntary exercise improved insulin resistance (HOMA-IR) and reduced glucose levels in diabetic rats. Since both crocin and voluntary exercise can increase VEGF-A protein expression in heart tissue, they probably are able to increase angiogenesis in diabetic animals.

Size, shape, and stamina: the impact of left ventricular geometry on exercise capacity.

PubMed

Lam, Carolyn S P; Grewal, Jasmine; Borlaug, Barry A; Ommen, Steve R; Kane, Garvan C; McCully, Robert B; Pellikka, Patricia A

2010-05-01

Although several studies have examined the cardiac functional determinants of exercise capacity, few have investigated the effects of structural remodeling. The current study evaluated the association between cardiac geometry and exercise capacity. Subjects with ejection fraction > or = 50% and no valvular disease, myocardial ischemia, or arrhythmias were identified from a large prospective exercise echocardiography database. Left ventricular mass index and relative wall thickness were used to classify geometry into normal, concentric remodeling, eccentric hypertrophy, and concentric hypertrophy. All of the subjects underwent symptom-limited treadmill exercise according to standard Bruce protocol. Maximal exercise tolerance was measured in metabolic equivalents. Of 366 (60+/-14 years; 57% male) subjects, 166 (45%) had normal geometry, 106 (29%) had concentric remodeling, 40 (11%) had eccentric hypertrophy, and 54 (15%) had concentric hypertrophy. Geometry was related to exercise capacity: in descending order, the maximum achieved metabolic equivalents were 9.9+/-2.8 in normal, 8.9+/-2.6 in concentric remodeling, 8.6+/-3.1 in eccentric hypertrophy, and 8.0+/-2.7 in concentric hypertrophy (all P<0.02 versus normal). Left ventricular mass index and relative wall thickness were negatively correlated with exercise tolerance in metabolic equivalents (r=-0.14; P=0.009 and r=-0.21; P<0.001, respectively). Augmentation of heart rate and ejection fraction with exercise were blunted in concentric hypertrophy compared with normal, even after adjusting for medications. In conclusion, the pattern of ventricular remodeling is related to exercise capacity among low-risk adults. Subjects with concentric hypertrophy display the greatest limitation, and this is related to reduced systolic and chronotropic reserve. Reverse remodeling strategies may prevent or treat functional decline in patients with structural heart disease.

Size, Shape and Stamina: The Impact of Left Ventricular Geometry on Exercise Capacity

PubMed Central

Lam, Carolyn S.P.; Grewal, Jasmine; Borlaug, Barry A.; Ommen, Steve R.; Kane, Garvan C.; McCully, Robert B.; Pellikka, Patricia A.

2010-01-01

While several studies have examined the cardiac functional determinants of exercise capacity, few have investigated the effects of structural remodeling. The current study evaluated the association between cardiac geometry and exercise capacity. Subjects with ejection fraction ≥ 50% and no valvular disease, myocardial ischemia or arrhythmias were identified from a large prospective exercise echocardiography database. Left ventricular mass index and relative wall thickness were used to classify geometry into normal, concentric remodeling, eccentric hypertrophy and concentric hypertrophy. All subjects underwent symptom-limited treadmill exercise according to standard Bruce protocol. Maximal exercise tolerance was measured in metabolic equivalents. Of 366 (60±14 years; 57% male) subjects, 166(45%) had normal geometry, 106(29%) had concentric remodeling, 40(11%) had eccentric hypertrophy and 54(15%) had concentric hypertrophy. Geometry was related to exercise capacity: in descending order, the maximum achieved metabolic equivalents was 9.9±2.8 in normal, 8.9±2.6 in concentric remodeling, 8.6±3.1 in eccentric hypertrophy and 8.0±2.7 in concentric hypertrophy (all p<0.02 vs normal). Left ventricular mass index and relative wall thickness were negatively correlated with exercise tolerance in metabolic equivalents (r= -0.14; p=0.009 and r= -0.21; p<0.001, respectively). Augmentation of heart rate and ejection fraction with exercise were blunted in concentric hypertrophy compared to normal, even after adjusting for medications. In conclusion, the pattern of ventricular remodeling is related to exercise capacity among low-risk adults. Subjects with concentric hypertrophy display the greatest limitation and this is related to reduced systolic and chronotropic reserve. Reverse remodeling strategies may prevent or treat functional decline in patients with structural heart disease. PMID:20215563

Effect of inpatient rehabilitation on quality of life and exercise capacity in long-term lung transplant survivors: a prospective, randomized study.

PubMed

Ihle, Franziska; Neurohr, Claus; Huppmann, Patrick; Zimmermann, Gregor; Leuchte, Hanno; Baumgartner, Rainer; Kenn, Klaus; Sczepanski, Bernd; Hatz, Rudolf; Czerner, Stephan; Frey, Lorenz; Ueberfuhr, Peter; Bittmann, Iris; Behr, Jürgen

2011-08-01

The purpose of this study was to examine the effect of an inpatient rehabilitation program on health-related quality of life (HRQOL) and exercise capacity (EC) in long-term (>1 year after lung transplantation) survivors (LTSs) in comparison to a control group (CG). Sixty LTSs, 4.5 ± 3.2 years after lung transplantation (LTx), were randomly assigned to two equally sized groups that were stratified for gender and underlying disease. Thirty LTSs (age 49 ± 13 years, 13 male and 17 females, 19 double LTxs, 7 BOS Stage ≥ 1) attended an inpatient rehabilitation program (intervention group, IG) for 23 ± 5 days. The CG (age 50 ± 12 years, 13 males and 17 females, 20 double LTxs, 2 BOS Stage ≥ 1) received medical standard therapy (physiotherapy). Patients were evaluated by cardiopulmonary exercise testing, 6-minute walk test (6MWT), SF-36, SGRQ and the Quality of Life Profile for Chronic Diseases questionnaire before and after (18 ± 3 days) the program. The groups were statistically indistinguishable in terms of clinical data. Each treatment group significantly improved their sub-maximal EC (6MWT: IG, 493 ± 90 m vs 538 ± 90 m, p < 0.001; CG, 490 ± 88 m vs 514 ± 89 m, p < 0.001) and maximal EC (VO(2peak): IG, 17.0 vs 18.5 ml/min/kg, p = 0.039; CG, 18.0 vs 19.5 ml/min/kg, p = 0.005), without reaching statistical significance between the groups. In both study groups, patients HRQOL tended to improve. Significant correlations were found between EC parameters and HRQOL scales. Our data suggest that structured physical training may improve exercise tolerance in LTS. Our study results did not demonstrate a significant benefit of an inpatient over an outpatient exercise program. Copyright © 2011 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.

The Effect of the Modified Eighth Section of Eight-Section Brocade on Osteoporosis in Postmenopausal Women

PubMed Central

Liu, Bao-Xin; Chen, Shu-Peng; Li, Yu-Dong; Wang, Ji; Zhang, Bin; Lin, Ying; Guan, Jun-Hui; Cai, Ying-Feng; Liang, Zhu; Zheng, Fang

2015-01-01

Abstract Osteoporosis and related fragility fractures represent a serious and global public health problem. To evaluate whether the modified eighth section of Eight-section Brocade (MESE) exercise could improve the symptom and indexes associated with osteoporosis in postmenopausal women. Guangzhou and Liuzhou hospital of traditional Chinese medicine in China. Women (n = 198) aged 50 to 75 years were randomized into Control, Ca, MESE, and MESE + Ca. Subjects in Ca and MESE groups were separately asked to consume thrice daily Calcium Carbonate Chewable D3 tablet and to perform thrice daily MESE exercise by 7 repetitions per time for 12 months. Subjects in MESE + Ca group performed such the combined treatment project for 12 months. Body height and Hospital for Special Surgery (HSS) scores of both knees, chronic back pain visual analogue scale scores (VAS), bone mineral density (BMD) at L2 to L4 and the left femoral neck, 3-feet Up and Go Test (3′) and one-leg Stance (OLS). In our study, the improvement in chronic back pain of the patients in Ca, MESE, and MESE + Ca group was better than that in control group. There was 1.9% and 1.7%, 2.3%, and 2.1% net profit in left femoral neck and lumbar BMD after the treatment for 12 months in MESE and MESE + Ca groups. For the balance capacity, the subjects in MESE and MESE + Ca groups secured much better performance than those in Ca and control group after the treatment for 12 months (P < 0.001, P < 0.001). The treatment of MESE exercise is the most effective for the improvement of the symptom and indexes in postmenopausal women. Importantly, the low attrition and the high exercise compliance indicate that MESE exercise is safe, feasible, and well tolerated by postmenopausal women. PMID:26107684

Preoperative exercise training prevents functional decline after lung resection surgery: a randomized, single-blind controlled trial.

PubMed

Sebio García, Raquel; Yáñez-Brage, Maria Isabel; Giménez Moolhuyzen, Esther; Salorio Riobo, Marta; Lista Paz, Ana; Borro Mate, Jose María

2017-08-01

To investigate the effects of a preoperative pulmonary rehabilitation programme in patients with lung cancer undergoing video-assisted thoracic surgery. Randomized, single-blind controlled trial. Teaching hospital. Patients with suspected or confirmed lung cancer undergoing video-assisted thoracic surgery. Participants were randomized to either a prehabilitation group or a control group. Participants in the prehabilitation group underwent a combination of moderate endurance and resistance training plus breathing exercises three to five times per week. The primary outcome of the study was exercise capacity. Secondary outcomes were muscle strength (Senior Fitness Test), health-related quality of life (Short-Form 36) and the postoperative outcomes. Patients were evaluated at baseline (before randomization), presurgery (only the prehabilitation group), after surgery and three months post-operatively. A total of 40 patients were randomized and 22 finished the study (10 in the prehabilitation group and 12 in the control group). Three patients were lost to follow-up at three months. After the training, there was a statistically significant improvement in exercise tolerance (+397 seconds, p = 0.0001), the physical summary component of the SF-36 (+4.4 points, p = 0.008) and muscle strength ( p < 0.01). There were no significant differences between groups after surgery. However, three months postoperatively, significant differences were found in the mean change of exercise capacity ( p = 0.005), physical summary component ( p = 0.001) and upper and lower body strength ( p = 0.045 and p = 0.002). A pulmonary rehabilitation programme before video-assisted thoracic surgery seems to improve patients' preoperative condition and may prevent functional decline after surgery. Clinical Registration Number: NCT01963923 (Registration date 10/10/2013).

Spa therapy in the treatment of knee osteoarthritis: a large randomised multicentre trial

PubMed Central

Forestier, R; Desfour, H; Tessier, J-M; Françon, A; Foote, A M; Genty, C; Rolland, C; Roques, C-F; Bosson, J-L

2010-01-01

Objective To determine whether spa therapy, plus home exercises and usual medical treatment provides any benefit over exercises and usual treatment, in the management of knee osteoarthritis. Methods Large multicentre randomised prospective clinical trial of patients with knee osteoarthritis according to the American College of Rheumatology criteria, attending French spa resorts as outpatients between June 2006 and April 2007. Zelen randomisation was used so patients were ignorant of the other group and spa personnel were not told which patients were participating. The main endpoint criteria were patient self-assessed. All patients continued usual treatments and performed daily standardised home exercises. The spa therapy group also received 18 days of spa therapy (massages, showers, mud and pool sessions). Main Endpoint The number of patients achieving minimal clinically important improvement (MCII) at 6 months, defined as ≥19.9 mm on the visual analogue pain scale and/or ≥9.1 points in a normalised Western Ontario and McMaster Universities osteoarthritis index function score and no knee surgery. Results The intention to treat analysis included 187 controls and 195 spa therapy patients. At 6 months, 99/195 (50.8%) spa group patients had MCII and 68/187 (36.4%) controls (χ2=8.05; df=1; p=0.005). However, no improvement in quality of life (Short Form 36) or patient acceptable symptom state was observed at 6 months. Conclusion For patients with knee osteoarthritis a 3-week course of spa therapy together with home exercises and usual pharmacological treatments offers benefit after 6 months compared with exercises and usual treatment alone, and is well tolerated. Trial registration number NCT00348777. PMID:19734131

Exercise countermeasures for bed rest deconditioning

NASA Technical Reports Server (NTRS)

Greenleaf, John (Editor)

1989-01-01

The major objectives were to evaluate the efficiency of different modes of exercise (isotonic and isokinetic) for countering the effects of bed rest deconditioning on work capacity (peak oxygen uptake), muscular strength, orthostatic tolerance, posture, equilibrium and gait; and to collect additional data of a more fundamental nature to help understand how these deconditioning responses occur. These data will be used for writing prescriptions for exercise to be utilized by astronauts for maintaining work capacity and well-being on Freedom Station, and to determine what exercise devices should be place in the station.

Integrated physiological mechanisms of exercise performance, adaptation, and maladaptation to heat stress.

PubMed

Sawka, Michael N; Leon, Lisa R; Montain, Scott J; Sonna, Larry A

2011-10-01

This article emphasizes significant recent advances regarding heat stress and its impact on exercise performance, adaptations, fluid electrolyte imbalances, and pathophysiology. During exercise-heat stress, the physiological burden of supporting high skin blood flow and high sweating rates can impose considerable cardiovascular strain and initiate a cascade of pathophysiological events leading to heat stroke. We examine the association between heat stress, particularly high skin temperature, on diminishing cardiovascular/aerobic reserves as well as increasing relative intensity and perceptual cues that degrade aerobic exercise performance. We discuss novel systemic (heat acclimation) and cellular (acquired thermal tolerance) adaptations that improve performance in hot and temperate environments and protect organs from heat stroke as well as other dissimilar stresses. We delineate how heat stroke evolves from gut underperfusion/ischemia causing endotoxin release or the release of mitochondrial DNA fragments in response to cell necrosis, to mediate a systemic inflammatory syndrome inducing coagulopathies, immune dysfunction, cytokine modulation, and multiorgan damage and failure. We discuss how an inflammatory response that induces simultaneous fever and/or prior exposure to a pathogen (e.g., viral infection) that deactivates molecular protective mechanisms interacts synergistically with the hyperthermia of exercise to perhaps explain heat stroke cases reported in low-risk populations performing routine activities. Importantly, we question the "traditional" notion that high core temperature is the critical mediator of exercise performance degradation and heat stroke. Published 2011. This article is a U.S. Government work and is in the public domain in the USA.

Physiological intensity profile, exercise load and performance predictors of a 65-km mountain ultra-marathon.

PubMed

Fornasiero, Alessandro; Savoldelli, Aldo; Fruet, Damiano; Boccia, Gennaro; Pellegrini, Barbara; Schena, Federico

2018-06-01

The aims of the study were to describe the physiological profile of a 65-km (4000-m cumulative elevation gain) running mountain ultra-marathon (MUM) and to identify predictors of MUM performance. Twenty-three amateur trail-runners performed anthropometric evaluations and an uphill graded exercise test (GXT) for VO 2max, ventilatory thresholds (VTs), power outputs (PMax, PVTs) and heart rate response (HRmax, HR@VTs). Heart rate (HR) was monitored during the race and intensity was expressed as: Zone I (VT2) for exercise load calculation (training impulse, TRIMP). Mean race intensity was 77.1%±4.4% of HRmax distributed as: 85.7%±19.4% Zone I, 13.9%±18.6% Zone II, 0.4%±0.9% Zone III. Exercise load was 766±110 TRIMP units. Race time (11.8±1.6h) was negatively correlated with VO 2max (r = -0.66, P <0.001) and PMax (r = -0.73, P <0.001), resulting these variables determinant in predicting MUM performance, whereas exercise thresholds did not improve performance prediction. Laboratory variables explained only 59% of race time variance, underlining the multi-factorial character of MUM performance. Our results support the idea that VT1 represents a boundary of tolerable intensity in this kind of events, where exercise load is extremely high. This information can be helpful in identifying optimal pacing strategies to complete such extremely demanding MUMs.

Community-Based Adaptive Physical Activity Program for Chronic Stroke: Feasibility, Safety, and Efficacy of the Empoli Model

PubMed Central

Stuart, Mary; Benvenuti, Francesco; Macko, Richard; Taviani, Antonio; Segenni, Lucianna; Mayer, Federico; Sorkin, John D.; Stanhope, Steven J.; Macellari, Velio; Weinrich, Michael

2010-01-01

Objective To determine whether Adaptive Physical Activity (APA-stroke), a community-based exercise program for participants with hemiparetic stroke, improves function in the community. Methods Nonrandomized controlled study in Tuscany, Italy, of participants with mild to moderate hemiparesis at least 9 months after stroke. Forty-nine participants in a geographic health authority (Empoli) were offered APA-stroke (40 completed the study). Forty-four control participants in neighboring health authorities (Florence and Pisa) received usual care (38 completed the study). The APA intervention was a community-based progressive group exercise regimen that included walking, strength, and balance training for 1 hour, thrice a week, in local gyms, supervised by gym instructors. No serious adverse clinical events occurred during the exercise intervention. Outcome measures included the following: 6-month change in gait velocity (6-Minute Timed Walk), Short Physical Performance Battery (SPPB), Berg Balance Scale, Stroke Impact Scale (SIS), Barthel Index, Hamilton Rating Scale for Depression, and Index of Caregivers Strain. Results After 6 months, the intervention group improved whereas controls declined in gait velocity, balance, SPPB, and SIS social participation domains. These between-group comparisons were statistically significant at P < .00015. Individuals with depressive symptoms at baseline improved whereas controls were unchanged (P < .003). Oral glucose tolerance tests were performed on a subset of participants in the intervention group. For these individuals, insulin secretion declined 29% after 6 months (P = .01). Conclusion APA-stroke appears to be safe, feasible, and efficacious in a community setting. PMID:19318465

Dietary supplementation with omega-3 fatty acids and oleate enhances exercise training effects in patients with metabolic syndrome.

PubMed

Ortega, Juan F; Morales-Palomo, Felix; Fernandez-Elias, Valentin; Hamouti, Nassim; Bernardo, Francisco J; Martin-Doimeadios, Rosa C; Nelson, Rachael K; Horowitz, Jeffrey F; Mora-Rodriguez, Ricardo

2016-08-01

We studied the effects of exercise training alone or combined with dietary supplementation of omega-3 polyunsaturated fatty acids (Ω-3PUFA) and oleate on metabolic syndrome (MSyn) components and other markers of cardiometabolic health. Thirty-six patients with MSyn underwent 24 weeks of high-intensity interval training. In a double-blind randomized design, half of the group ingested 500 mL/day of semi-skim milk (8 g of fat; placebo milk) whereas the other half ingested 500 mL/day of skim milk enriched with 275 mg of Ω-3PUFA and 7.5 g of oleate (Ω-3 + OLE). Ω-3 + OLE treatment elevated 30% plasma Ω-3PUFA but not significantly (P = 0.286). Improvements in VO2peak (12.8%), mean blood pressure (-7.1%), waist circumference (-1.8%), body fat mass (-2.9%), and trunk fat mass (-3.3%) were similar between groups. However, insulin sensitivity (measured by intravenous glucose tolerance test), serum concentration of C-reactive protein, and high-density lipoprotein improved only in the Ω-3 + OLE group by 31.5%, 32.1%, and 10.3%, respectively (all P < 0.05). Fasting serum triacylglycerol, glucose, and plasma fibrinogen concentrations did not improve in either group after 24 weeks of intervention. Diet supplementation with Ω-3PUFA and oleate enhanced cardiometabolic benefits of intense aerobic exercise training in patients with MSyn. © 2016 The Obesity Society.

Exercise Training and Peripheral Arterial Disease

PubMed Central

Haas, Tara L.; Lloyd, Pamela G.; Yang, Hsiao-Tung; Terjung, Ronald L.

2013-01-01

Peripheral arterial disease (PAD) is a common vascular disease that reduces blood flow capacity to the legs of patients. PAD leads to exercise intolerance that can progress in severity to greatly limit mobility, and in advanced cases leads to frank ischemia with pain at rest. It is estimated that 12–15 million people in the United States are diagnosed with PAD, with a much larger population that is undiagnosed. The presence of PAD predicts a 50–1500% increase in morbidity and mortality, depending on severity. Treatment of patients with PAD is limited to modification of cardiovascular disease risk factors, pharmacological intervention, surgery, and exercise therapy. Extended exercise programs that involve walking ~5 times/wk, at a significant intensity that requires frequent rest periods, are most significant. Pre-clinical studies and virtually all clinical trials demonstrate the benefits of exercise therapy, including: improved walking tolerance, modified inflammatory/hemostatic markers, enhanced vasoresponsiveness, adaptations within the limb (angiogenesis, arteriogenesis, mitochondrial synthesis) that enhance oxygen delivery and metabolic responses, potentially delayed progression of the disease, enhanced quality of life indices, and extended longevity. A synthesis is provided as to how these adaptations can develop in the context of our current state of knowledge and events known to be orchestrated by exercise. The benefits are so compelling that exercise prescription should be an essential option presented to patients with PAD in the absence of contraindications. Obviously, selecting for a life style pattern, that includes enhanced physical activity prior to the advance of PAD limitations, is the most desirable and beneficial. PMID:23720270

Exercise training promotes cardioprotection through oxygen-sparing action in high fat-fed mice.

PubMed

Lund, J; Hafstad, A D; Boardman, N T; Rossvoll, L; Rolim, N P; Ahmed, M S; Florholmen, G; Attramadal, H; Wisløff, U; Larsen, T S; Aasum, E

2015-04-15

Although exercise training has been demonstrated to have beneficial cardiovascular effects in diabetes, the effect of exercise training on hearts from obese/diabetic models is unclear. In the present study, mice were fed a high-fat diet, which led to obesity, reduced aerobic capacity, development of mild diastolic dysfunction, and impaired glucose tolerance. Following 8 wk on high-fat diet, mice were assigned to 5 weekly high-intensity interval training (HIT) sessions (10 × 4 min at 85-90% of maximum oxygen uptake) or remained sedentary for the next 10 constitutive weeks. HIT increased maximum oxygen uptake by 13%, reduced body weight by 16%, and improved systemic glucose homeostasis. Exercise training was found to normalize diastolic function, attenuate diet-induced changes in myocardial substrate utilization, and dampen cardiac reactive oxygen species content and fibrosis. These changes were accompanied by normalization of obesity-related impairment of mechanical efficiency due to a decrease in work-independent myocardial oxygen consumption. Finally, we found HIT to reduce infarct size by 47% in ex vivo hearts subjected to ischemia-reperfusion. This study therefore demonstrated for the first time that exercise training mediates cardioprotection following ischemia in diet-induced obese mice and that this was associated with oxygen-sparing effects. These findings highlight the importance of optimal myocardial energetics during ischemic stress. Copyright © 2015 the American Physiological Society.

Physiological responses to cold (10° C) in men after six months' practice of yoga exercises

NASA Astrophysics Data System (ADS)

Selvamurthy, W.; Ray, U. S.; Hegde, K. S.; Sharma, R. P.

1988-09-01

A study was conducted on 30 healthy soldiers (age: 40 46 years) to assess the effect of selected yogic exercises (asanas) on some physiological responses to cold exposure. They were randomly divided into two groups of 15 each. One group performed regular physical exercises of physical training (PT), while the other group practised yogic exercises. At the end of 6 months of training, both the groups were exposed together to cold stress at 10°C for 2 h, and the following parameters were periodically monitored during cold exposure: heart rate ( fH), blood pressure ( BP), cardiac output(dot Q_c ), oral temperature (Tor), skin temperature ( T sk), respiratory rate ( fR), minute ventilation(dot V_E ), oxygen consumption(dot V_{O_2 } ), and shivering response by integrated electromyogram (EMG). There were progressive increases in BP, fR,dot V_E ,dot V_{O_2 } , anddot Q_c and decreases in fH, T or and T sk during cold exposure in both the groups. However, the decrease in T or and the increases indot V_{O_2 } anddot V_E were relatively lower ( P<0.01) in the yoga group as compared to the PT group. The shivering response appeared much earlier and was more intense in the PT group. These findings suggest that practice of yoga exercises may improve cold tolerance.

Is Moderate Intensity Exercise Training Combined with High Intensity Interval Training More Effective at Improving Cardiorespiratory Fitness than Moderate Intensity Exercise Training Alone?

PubMed Central

Roxburgh, Brendon H.; Nolan, Paul B.; Weatherwax, Ryan M.; Dalleck, Lance C.

2014-01-01

The purpose of this study was to compare the effectiveness of either continuous moderate intensity exercise training (CMIET) alone vs. CMIET combined with a single weekly bout of high intensity interval training (HIIT) on cardiorespiratory fitness. Twenty nine sedentary participants (36.3 ± 6.9 yrs) at moderate risk of cardiovascular disease were recruited for 12 weeks of exercise training on a treadmill and cycle ergometer. Participants were randomised into three groups: CMIET + HIIT (n = 7; 8-12 x 60 sec at 100% VO2max, 150 sec active recovery), CMIET (n = 6; 30 min at 45-60% oxygen consumption reserve (VO2R)) and a sedentary control group (n = 7). Participants in the CMIET + HIIT group performed a single weekly bout of HIIT and four weekly sessions of CMIET, whilst the CMIET group performed five weekly CMIET sessions. Probabilistic magnitude-based inferences were determined to assess the likelihood that the true value of the effect represents substantial change. Relative VO2max increased by 10.1% (benefit possible relative to control) in in the CMIET + HIIT group (32.7 ± 9.2 to 36.0 ± 11.5 mL·kg-1·min-1) and 3.9% (benefit possible relative to control) in the CMIET group (33.2 ± 4.0 to 34.5 ± 6.1 mL·kg-1·min-1), whilst there was a 5.7% decrease in the control group (30.0 ± 4.6 to 28.3 ± 6.5 mL·kg-1·min-1). It was ‘unclear’ if a clinically significant difference existed between the effect of CMIET + HIIT and CMIET on the change in VO2max. Both exercising groups showed clinically meaningful improvements in VO2max. Nevertheless, it remains ‘unclear’ whether one type of exercise training regimen elicits a superior improvement in cardiorespiratory fitness relative to its counterpart. Key Points Both continuous moderate intensity exercise training (CMIET) alone and CMIET combined with a single weekly bout of high intensity interval training (CMIET + HIIT) elicit ‘possibly beneficial’ clinically meaningful improvements in cardiorespiratory fitness. Cardiorespiratory fitness improved by ~1.0 MET in the CMIET + HIIT exercise intervention group, which likely leads to important long-term prevention implications as a 1 MET increase in cardiorespiratory fitness has been linked with an 18% reduction in deaths due to CVD. There was 100% adherence to interval sessions in the CMIET + HIIT group, suggesting this combination of training can be well-tolerated in previously inactive overweight/obese individuals. PMID:25177202

Design of the Physical exercise during Adjuvant Chemotherapy Effectiveness Study (PACES): a randomized controlled trial to evaluate effectiveness and cost-effectiveness of physical exercise in improving physical fitness and reducing fatigue.

PubMed

van Waart, Hanna; Stuiver, Martijn M; van Harten, Wim H; Sonke, Gabe S; Aaronson, Neil K

2010-12-07

Cancer chemotherapy is frequently associated with a decline in general physical condition, exercise tolerance, and muscle strength and with an increase in fatigue. While accumulating evidence suggests that physical activity and exercise interventions during chemotherapy treatment may contribute to maintaining cardiorespiratory fitness and strength, the results of studies conducted to date have not been consistent. Additional research is needed to determine the optimal intensity of exercise training programs in general and in particular the relative effectiveness of supervised, outpatient (hospital- or physical therapy practice-based) versus home-based programs. This multicenter, prospective, randomized trial will evaluate the effectiveness of a low to moderate intensity, home-based, self-management physical activity program, and a high intensity, structured, supervised exercise program, in maintaining or enhancing physical fitness (cardiorespiratory fitness and muscle strength), in minimizing fatigue and in enhancing the health-related quality of life (HRQoL). Patients receiving adjuvant chemotherapy for breast or colon cancer (n = 360) are being recruited from twelve hospitals in the Netherlands, and randomly allocated to one of the two treatment groups or to a 'usual care' control group. Performance-based and self-reported outcomes are assessed at baseline, at the end of chemotherapy and at six month follow-up. This large, multicenter, randomized clinical trial will provide additional empirical evidence regarding the effectiveness of physical exercise during adjuvant chemotherapy in enhancing physical fitness, minimizing fatigue, and maintaining or enhancing patients' quality of life. If demonstrated to be effective, exercise intervention programs will be a welcome addition to the standard program of care offered to patients with cancer receiving chemotherapy. This study is registered at the Netherlands Trial Register (NTR 2159).

Ventilated vest and tolerance for intermittent exercise in hot, dry conditions with military clothing.

PubMed

Barwood, Martin J; Newton, Phillip S; Tipton, Michael J

2009-04-01

Recent research has focused on developing air-ventilated garments to improve evaporative cooling in military settings. This study assessed a ventilated vest (Vest) in hot (45 degrees C), dry (10% RH) ambient conditions over 6 h of rest and exercise. It was hypothesized that the Vest would lower the thermal strain and increase the amount of exercise done by subjects. Eight healthy heat-acclimated men, wearing combat clothing, body armor, and a 19-kg load in webbing walked on a treadmill at 5 km h(-1) at a 2% incline until rectal temperature (T(rec)) reached 38.5 degrees C. They then rested until T(re) reached 38 degrees C, at which point they recommenced walking. On one occasion the subjects wore a Vest, blowing ambient air around the torso. On the second occasion subjects did not wear the vest (NoVest). Exercise/rest ratio, T(rec), skin temperature (T(sk)), sweat responses, rating of perceived exertion (RPE), and thermal comfort (TC) were measured. Subjects wearing theVest exercised for significantly longer (18%; 11 min/h) as a percentage of total exposure time, stopped exercise significantly less often [Mean (SD); NoVest: 3 (2) stops; Vest: 1 (2) stops], and maintained significantly lower skin temperature under the body armor [T(chest): NoVest 37.55 (0.51) degrees C; Vest: 35.33 (1.00) degrees C; T(back): NoVest: 36.85 (0.83) degrees C; Vest: 35.84 (0.88) degrees C]. The Vest provided 28 W of cooling during exercise and 73 W when at rest as estimated by thermometry. A ventilated vest can provide cooling, and thereby reduce thermal strain and increase exercise done in dry environmental temperatures up to 45 degrees C, without causing skin irritation and discomfort.

A Descriptive Analysis of Exercise Tolerance Test at Seremban Hospital : An Audit for the Year 2001

PubMed Central

Mohamed, Abdul Latiff; Nee, Chan Chee; Azzad, Ahmed

2004-01-01

Our purpose is to report on the epidemiological variables and their association with the results of the exercise tolerance test (ETT) in the series of patients referred for standard diagnostic ETT at Seremban Hospital during the year 2001. ETT is widely performed, but, in Malaysia, an analysis of the associations between the epidemiological data and the results of the ETT has not been presented. All patients referred for ETT at Seremban Hospital who underwent exercise treadmill tests for the year 2001 were taken as the study population. Demographic details and patients with established heart disease (i.e. prior coronary bypass surgery, myocardial infarction, or congestive heart failure) were noted. Clinical and ETT variables were collected retrospectively from the hospital records. Testing and data management were performed in a standardized fashion with a computer-assisted protocol. This study showed that there was no significant predictive epidemiological variable on the results of the ETT. However, it was found that there was statistically significant difference between the peak exercise time of males and females undergoing the ETT. PMID:22973128

Cardiopulmonary exercise testing is well tolerated in people with Alzheimer-related cognitive impairment.

PubMed

Billinger, Sandra A; Vidoni, Eric D; Greer, Colby S; Graves, Rasinio S; Mattlage, Anna E; Burns, Jeffrey M

2014-09-01

To retrospectively assess whether cardiopulmonary exercise testing would be well tolerated in individuals with Alzheimer disease (AD) compared with a nondemented peer group. We retrospectively reviewed 575 cardiopulmonary exercise tests (CPETs) in individuals with and without cognitive impairment caused by AD. University medical center. Exercise tests (N=575) were reviewed for nondemented individuals (n=340) and those with AD-related cognitive impairment (n=235). Not applicable. The main outcome measure for this study was reporting the reason for CPET termination. The hypothesis reported was formulated after data collection. We found that in cognitively impaired individuals, CPETs were terminated because of fall risk more often, but that overall test termination was infrequent-5.5% versus 2.1% (P=.04) in peers without cognitive impairment. We recorded 6 cardiovascular and 7 fall risk events in those with AD, compared with 7 cardiovascular and 0 fall risk events in those without cognitive impairment. Our findings support using CPETs to assess peak oxygen consumption in older adults with cognitive impairment caused by AD. Copyright © 2014 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Continuous low- to moderate-intensity exercise training is as effective as moderate- to high-intensity exercise training at lowering blood HbA(1c) in obese type 2 diabetes patients.

PubMed

Hansen, D; Dendale, P; Jonkers, R A M; Beelen, M; Manders, R J F; Corluy, L; Mullens, A; Berger, J; Meeusen, R; van Loon, L J C

2009-09-01

Exercise represents an effective interventional strategy to improve glycaemic control in type 2 diabetes patients. However, the impact of exercise intensity on the benefits of exercise training remains to be established. In the present study, we compared the clinical benefits of 6 months of continuous low- to moderate-intensity exercise training with those of continuous moderate- to high-intensity exercise training, matched for energy expenditure, in obese type 2 diabetes patients. Fifty male obese type 2 diabetes patients (age 59 +/- 8 years, BMI 32 +/- 4 kg/m(2)) participated in a 6 month continuous endurance-type exercise training programme. All participants performed three supervised exercise sessions per week, either 55 min at 50% of whole body peak oxygen uptake (VO(2)peak (low to moderate intensity) or 40 min at 75% of VO(2)peak (moderate to high intensity). Oral glucose tolerance, blood glycated haemoglobin, lipid profile, body composition, maximal workload capacity, whole body and skeletal muscle oxidative capacity and skeletal muscle fibre type composition were assessed before and after 2 and 6 months of intervention. The entire 6 month intervention programme was completed by 37 participants. Continuous endurance-type exercise training reduced blood glycated haemoglobin levels, LDL-cholesterol concentrations, body weight and leg fat mass, and increased VO(2)peak, lean muscle mass and skeletal muscle cytochrome c oxidase and citrate synthase activity (p < 0.05). No differences were observed between the groups training at low to moderate or moderate to high intensity. When matched for energy cost, prolonged continuous low- to moderate-intensity endurance-type exercise training is equally effective as continuous moderate- to high-intensity training in lowering blood glycated haemoglobin and increasing whole body and skeletal muscle oxidative capacity in obese type 2 diabetes patients. ISRCTN32206301 None.

A Moderate-Intensity Weight-Bearing Exercise Program for a Person With Type 2 Diabetes and Peripheral Neuropathy

PubMed Central

Hastings, Mary K.; Mueller, Michael J.

2012-01-01

Background and Purpose The exercise guidelines for people with diabetes mellitus and peripheral neuropathy (DM+PN) have recently changed to allow moderate-intensity weight-bearing exercise, but there are few reports in the literature describing appropriate weight-bearing exercise for those with DM+PN. This case report describes a successful and safe progressive exercise program for an individual with DM+PN. Case Description The patient was a 76-year-old man with a 30-year history of DM+PN. He participated in a 12-week, moderate-intensity, progressive exercise program (heart rate approximately 75% of maximum heart rate; rate of perceived exertion=11–13; 3 times per week) involving walking on a treadmill, balance exercises, and strengthening exercises for the lower extremities using body weight resistance. Outcomes Measurements were taken before and after the 12 weeks of exercise. The patient's Six-Minute Walk Test distance increased from 1,200 to 1,470 ft. His Physical Performance Test score did not change. His Foot and Ankle Ability Measure questionnaire score improved from 89 to 98. Dorsiflexor and plantar-flexor peak torque increased (dorsiflexor peak torque: right side=4.5–4.6 N·m, left side=2.8–3.8 N·m; plantar-flexor peak torque: right side=44.7–62.4 N·m, left side=40.8–56.0 N·m), as did his average daily step count (6,176–8,273 steps/day). Close monitoring of the plantar surface of the feet indicated that the exercise program was well tolerated and there were no adverse events. Discussion and Conclusions This case report describes a moderate-intensity exercise program that was successful in increasing some measures of muscle strength, physical function, and activity without causing injury in an individual with DM+PN. PMID:21921252

Vibration Therapy to Prevent Bone Loss and Falls: Mechanisms and Efficacy.

PubMed

Beck, Belinda R

2015-12-01

A considerable volume of evidence has accumulated to suggest that whole-body vibration (WBV) may have a therapeutic role to play in the prevention of osteoporotic fracture, particularly for individuals who are unable to tolerate vigorous exercise interventions. There is moderate to strong evidence that WBV will prevent falls (likely due to enhanced neuromuscular function), but also some indication that the effects of WBV do not outstrip those of targeted exercise. Animal data indicates that WBV will also improve bone mass, including preventing loss due to hormone withdrawal, disuse and glucocorticoid exposure. Human trials, however, have produced equivocal outcomes for bone. Positive trends are apparent at the hip and spine, but shortcomings in study designs have limited statistical power. The mechanism of the vibration effect on bone tissue is likely to be mechanical coupling between an oscillating cell nucleus and the cytoskeleton. More robust dose-response human data are required before therapeutic guidelines can be developed.

Reduction in Reactive Oxygen Species Production by Mitochondria From Elderly Subjects With Normal and Impaired Glucose Tolerance

PubMed Central

Ghosh, Sangeeta; Lertwattanarak, Raweewan; Lefort, Natalie; Molina-Carrion, Marjorie; Joya-Galeana, Joaquin; Bowen, Benjamin P.; de Jesus Garduno-Garcia, Jose; Abdul-Ghani, Muhammad; Richardson, Arlan; DeFronzo, Ralph A.; Mandarino, Lawrence; Van Remmen, Holly; Musi, Nicolas

2011-01-01

OBJECTIVE Aging increases the risk of developing impaired glucose tolerance (IGT) and type 2 diabetes. It has been proposed that increased reactive oxygen species (ROS) generation by dysfunctional mitochondria could play a role in the pathogenesis of these metabolic abnormalities. We examined whether aging per se (in subjects with normal glucose tolerance [NGT]) impairs mitochondrial function and how this relates to ROS generation, whether older subjects with IGT have a further worsening of mitochondrial function (lower ATP production and elevated ROS generation), and whether exercise reverses age-related changes in mitochondrial function. RESEARCH DESIGN AND METHODS Mitochondrial ATP and ROS production were measured in muscle from younger individuals with NGT, older individuals with NGT, and older individuals with IGT. Measurements were performed before and after 16 weeks of aerobic exercise. RESULTS ATP synthesis was lower in older subjects with NGT and older subjects with IGT versus younger subjects. Notably, mitochondria from older subjects (with NGT and IGT) displayed reduced ROS production versus the younger group. ATP and ROS production were similar between older groups. Exercise increased ATP synthesis in the three groups. Mitochondrial ROS production also increased after training. Proteomic analysis revealed downregulation of several electron transport chain proteins with aging, and this was reversed by exercise. CONCLUSIONS Old mitochondria from subjects with NGT and IGT display mitochondrial dysfunction as manifested by reduced ATP production but not with respect to increased ROS production. When adjusted to age, the development of IGT in elderly individuals does not involve changes in mitochondrial ATP and ROS production. Lastly, exercise reverses the mitochondrial phenotype (proteome and function) of old mitochondria. PMID:21677280

Aerobic exercise training improves oxidative stress and ubiquitin proteasome system activity in heart of spontaneously hypertensive rats.

PubMed

de Andrade, Luiz Henrique Soares; de Moraes, Wilson Max Almeida Monteiro; Matsuo Junior, Eduardo Hiroshi; de Orleans Carvalho de Moura, Elizabeth; Antunes, Hanna Karen Moreira; Montemor, Jairo; Antonio, Ednei Luiz; Bocalini, Danilo Sales; Serra, Andrey Jorge; Tucci, Paulo José Ferreira; Brum, Patricia Chakur; Medeiros, Alessandra

2015-04-01

The activity of the ubiquitin proteasome system (UPS) and the level of oxidative stress contribute to the transition from compensated cardiac hypertrophy to heart failure in hypertension. Moreover, aerobic exercise training (AET) is an important therapy for the treatment of hypertension, but its effects on the UPS are not completely known. The aim of this study was to evaluate the effect of AET on UPS's activity and oxidative stress level in heart of spontaneously hypertensive rats (SHR). A total of 53 Wistar and SHR rats were randomly divided into sedentary and trained groups. The AET protocol was 5×/week in treadmill for 13 weeks. Exercise tolerance test, non-invasive blood pressure measurement, echocardiographic analyses, and left ventricle hemodynamics were performed during experimental period. The expression of ubiquitinated proteins, 4-hydroxynonenal (4-HNE), Akt, phospho-Akt(ser473), GSK3β, and phospho-GSK3β(ser9) were analyzed by western blotting. The evaluation of lipid hydroperoxide concentration was performed using the xylenol orange method, and the proteasomal chymotrypsin-like activity was measured by fluorimetric assay. Sedentary hypertensive group presented cardiac hypertrophy, unaltered expression of total Akt, phospho-Akt, total GSK3β and phospho-GSK3β, UPS hyperactivity, increased lipid hydroperoxidation as well as elevated expression of 4-HNE but normal cardiac function. In contrast, AET significantly increased exercise tolerance, decreased resting systolic blood pressure and heart rate in hypertensive animals. In addition, the AET increased phospho-Akt expression, decreased phospho-GSK3β, and did not alter the expression of total Akt, total GSK3β, and ubiquitinated proteins, however, significantly attenuated 4-HNE levels, lipid hydroperoxidation, and UPS's activity toward normotensive group levels. Our results provide evidence for the main effect of AET on attenuating cardiac ubiquitin proteasome hyperactivity and oxidative stress in SHR rats.

Effects of insulin and exercise training on FGF21, its receptors and target genes in obesity and type 2 diabetes.

PubMed

Kruse, Rikke; Vienberg, Sara G; Vind, Birgitte F; Andersen, Birgitte; Højlund, Kurt

2017-10-01

Pharmacological doses of FGF21 improve glucose tolerance, lipid metabolism and energy expenditure in rodents. Induced expression and secretion of FGF21 from muscle may increase browning of white adipose tissue (WAT) in a myokine-like manner. Recent studies have reported that insulin and exercise increase FGF21 in plasma. Obesity and type 2 diabetes are potentially FGF21-resistant states, but to what extent FGF21 responses to insulin and exercise training are preserved, and whether FGF21, its receptors and target genes are altered, remains to be established. The effects of insulin during euglycaemic-hyperinsulinaemic clamps and 10 week endurance training on serum FGF21 were examined in individuals with type 2 diabetes and in glucose tolerant overweight/obese and lean individuals. Gene expression of FGF21, its receptors and target genes in muscle and WAT biopsies was evaluated by quantitative real-time PCR (qPCR). Insulin increased serum and muscle FGF21 independent of overweight/obesity or type 2 diabetes, and there were no effects associated with exercise training. The insulin-induced increases in serum FGF21 and muscle FGF21 expression correlated tightly (p < 0.001). In WAT, overweight/obesity with and without type 2 diabetes led to reduced expression of KLB, but increased FGFR1c expression. However, the expression of most FGF21 target genes was unaltered except for reduced CIDEA expression in individuals with type 2 diabetes. Insulin-induced expression of muscle FGF21 correlates strongly with a rise in serum FGF21, and this response appears intact in overweight/obesity and type 2 diabetes. FGF21 resistance may involve reduced KLB expression in WAT. However, increased FGFR1c expression or other mechanisms seem to ensure adequate expression of most FGF21 target genes in WAT.

Calf tissue liquid stowage and muscular and deep vein distension in orthostatic tests after a 90-day head down bed rest

NASA Astrophysics Data System (ADS)

Arbeille, P.A.; Kerbeci, P.; Audebert, P.; Capri, A.; Pascaud, L.

2005-08-01

The objectives were to assess the contribution of (1) the calf veins distension and(2) the tissue liquid stowage during standtest, to orthostatic intolerance "OI" after a head down bed rest (HDBR) of 90days. Method: The population consisted of a control group (Co-gr, n=9) and an exercise Fly wheel counter-measure group (CM-gr, n=9). Calf vein cross sectional area (CSA) and surrounding tissue liquid content (tissue image darkness) were assessed by echography during pre and post HDBR stand-tests. Results: From supine to standing (post HDBR), the Tibial and muscular vein CSA increased significantly in non tolerant subjects whereas in tolerant subjects the vein CSA did not change. Post HDBR the tissue image darkness (proportional to tissue liquid content) increased more from supine to standing in non tolerant than in tolerant subjects. No significant difference were found between Co and exercise CM groups. Conclusion: High calf vein CSA and tissue liquid content increase at post-HDBR stand-test were significantly correlated with occurrence of OI but not with CM.

Endurance exercise training decreases capillary basement membrane width in older nondiabetic and diabetic adults.

PubMed

Williamson, J R; Hoffmann, P L; Kohrt, W M; Spina, R J; Coggan, A R; Holloszy, O

1996-03-01

The objectives of these studies were to 1) evaluate the relationships among age, glucose intolerance, and skeletal muscle capillary basement membrane (CBM) width (CBMW) and 2) determine the effects of exercise training on CBMW by comparing values of young (28 +/- 4 yr) and older (63 +/- 7 yr) athletes with those of age-matched sedentary control subjects and by measuring CBMW in older men and women before and after a 9-mo endurance-exercise training program. CBMW was measured in tissue samples obtained from the gastrocnemius muscle. CBMW in sedentary 64 +/- 3-yr-old subjects was 25% thicker than in sedentary 24 +/- 3-yr-old subjects. CBMW was similar in young and older athletes and was thinner than the CBMW of age-matched sedentary control subjects. There were no differences in CBMW among older sedentary individuals with normal or impaired glucose tolerance or mild non-insulin-dependent diabetes mellitus. Nine months of endurance exercise training reduced CBMW in older men and women by 30-40%, to widths that were not different from those of the young subjects; this response was independent of glucose tolerance status. These findings suggest that habitual exercise prevents the thickening of the skeletal muscle CBM that is characteristic of advancing age. Moreover, the thickening of the CBM appears to be readily reversed as a result of exercise training, even in older individuals.

Effectiveness of Artificial Gravity and Ergometric Exercise as a Countermeasure-Comparison between Everyday and Every Other Day Protocols

NASA Astrophysics Data System (ADS)

Iwase, Satoshi; Sugenoya, Junichi; Sato, Maki; Shimizu, Yuuki; Kanikowska, Dominika; Nishimura, Nooki; Takada, Hiroki; Takada, Masumi; Mano, Tadaki; Ishida, Koji; Akima, Hiroshi; Katayama, Keisho; Hirayanagi, Kaname; Shiozawa, Tomoki; Yajima, Katzuyoshi; Watanabe, Yoriko; Suzuki, Satomi; Fukunnaga, Tetsuo; Masuo, Yoshihisa

2008-06-01

Effectiveness of centrifuge-induced artificial gravity and ergometric exercise as a countermeasure to space deconditioning, including cardiovascular deconditioning, myatrophy, and osteoporosis, induced by 20 days of head-down bedrest., was examined in 12 healthy men in 2006, and 8 healthy men in 2007. Bedrest was performed with 2300 kcal of diet. Water intake was recommended more than the urine volume in a previous day. A new protocol for artificial gravity with ergometric exercise was adopted, with 1.6 G of artificial gravity at heart level and 60 W of exercise every day in 2006, and every other day in 2007. The load was suspended when subjects complained all-out, and was continued until 30 min cumulative total load time. Gravity was stepped up by 0.2 G or exercise load was stepped up by 15 W alternately when the subject endured the load for 5 min. Gravity tolerance was examined by using centrifuge, and anti-G score was determined before and after the bedrest. Not all result has been analyzed, however, effectiveness of artificial gravity with ergometric exercise was evidenced in orthostatic tolerance, physical fitness, cardiac function, myatrophy, and bone metabolism in everyday protocol, but not in every other day protocol. We concluded this everyday protocol was effective in cardiovascular deconditioning myatrophy, and bone metabolism.

Muscle metabolic responses during high-intensity intermittent exercise measured by 31P-MRS: relationship to the critical power concept

PubMed Central

Chidnok, Weerapong; DiMenna, Fred J.; Fulford, Jonathan; Bailey, Stephen J.; Skiba, Philip F.; Vanhatalo, Anni

2013-01-01

We investigated the responses of intramuscular phosphate-linked metabolites and pH (as assessed by 31P-MRS) during intermittent high-intensity exercise protocols performed with different recovery-interval durations. Following estimation of the parameters of the power-duration relationship, i.e., the critical power (CP) and curvature constant (W′), for severe-intensity constant-power exercise, nine male subjects completed three intermittent exercise protocols to exhaustion where periods of high-intensity constant-power exercise (60 s) were separated by different durations of passive recovery (18 s, 30 s and 48 s). The tolerable duration of exercise was 304 ± 68 s, 516 ± 142 s, and 847 ± 240 s for the 18-s, 30-s, and 48-s recovery protocols, respectively (P < 0.05). The work done >CP (W>CP) was significantly greater for all intermittent protocols compared with the subjects' W′, and this difference became progressively greater as recovery-interval duration was increased. The restoration of intramuscular phosphocreatine concentration during recovery was greatest, intermediate, and least for 48 s, 30 s, and 18 s of recovery, respectively (P < 0.05). The W>CP in excess of W′ increased with greater durations of recovery, and this was correlated with the mean magnitude of muscle phosphocreatine reconstitution between work intervals (r = 0.61; P < 0.01). The results of this study show that during intermittent high-intensity exercise, recovery intervals allow intramuscular homeostasis to be restored, with the degree of restoration being related to the duration of the recovery interval. Consequently, and consistent with the intermittent CP model, the ability to perform W>CP during intermittent high-intensity exercise and, therefore, exercise tolerance, increases when recovery-interval duration is extended. PMID:24068048

Managing childhood and adolescent attention-deficit/hyperactivity disorder (ADHD) with exercise: A systematic review.

PubMed

Ng, Qin Xiang; Ho, Collin Yih Xian; Chan, Hwei Wuen; Yong, Bob Zheng Jie; Yeo, Wee-Song

2017-10-01

Attention deficit hyperactivity disorder (ADHD) is one of the most common neuropsychiatric disorders affecting some 8-10% of children worldwide. Increasing research has shed light on the life course of the disorder, suggesting that majority of children with ADHD will continue to have persistent symptoms into adulthood. The mainstay of ADHD management has been pharmacologic and behavioural/psychological interventions, with little attention paid to exercise as a potential management strategy. A systematic review, examining both the short-term and long-term effects of exercise on children with ADHD, is timely and necessary to guide further research in this area. Using the keywords [exercise OR physical OR activity OR sport] AND [attention deficit hyperactivity disorder OR ADHD OR ADDH], a preliminary search on the PubMed and Ovid database yielded 613 papers published in English between 1-Jan-1980 and 1-July-2016. Full articles were also reviewed for references of interest. A total of 30 studies were included in this systematic review. Both short-term and long-term studies support the clinical benefits of physical activity for individuals with ADHD. Cognitive, behavioural and physical symptoms of ADHD were alleviated in most instances, and the largest intervention effects were reported for mixed exercise programs. No adverse effects arising from physical exercise were reported in any of the studies, suggesting that exercise is a well-tolerated intervention. Physical activity, in particular moderate-to-intense aerobic exercise, is a beneficial and well-tolerated intervention for children and adolescents with ADHD. Future research should include more adequately-powered trials and investigate the ideal exercise prescription. Copyright © 2017 Elsevier Ltd. All rights reserved.

Exercise facilitates early recognition of cardiac and vascular remodeling in chronic thromboembolic pulmonary hypertension in swine.

PubMed

Stam, Kelly; van Duin, Richard W B; Uitterdijk, André; Cai, Zongye; Duncker, Dirk J; Merkus, Daphne

2018-03-01

Chronic thromboembolic pulmonary hypertension (CTEPH) develops in 4% of patients after pulmonary embolism and is accompanied by an impaired exercise tolerance, which is ascribed to the increased right ventricular (RV) afterload in combination with a ventilation/perfusion (V/Q) mismatch in the lungs. The present study aimed to investigate changes in arterial Po 2 and hemodynamics in response to graded treadmill exercise during development and progression of CTEPH in a novel swine model. Swine were chronically instrumented and received multiple pulmonary embolisms by 1) microsphere infusion (Spheres) over 5 wk, 2) endothelial dysfunction by administration of the endothelial nitric oxide synthase inhibitor N ω -nitro-l-arginine methyl ester (L-NAME) for 7 wk, 3) combined pulmonary embolisms and endothelial dysfunction (L-NAME + Spheres), or 4) served as sham-operated controls (sham). After a 9 wk followup, embolization combined with endothelial dysfunction resulted in CTEPH, as evidenced by mean pulmonary artery pressures of 39.5 ± 5.1 vs. 19.1 ± 1.5 mmHg (Spheres, P < 0.001), 22.7 ± 2.0 mmHg (L-NAME, P < 0.001), and 20.1 ± 1.5 mmHg (sham, P < 0.001), and a decrease in arterial Po 2 that was exacerbated during exercise, indicating V/Q mismatch. RV dysfunction was present after 5 wk of embolization, both at rest (trend toward increased RV end-systolic lumen area, P = 0.085, and decreased stroke volume index, P = 0.042) and during exercise (decreased stroke volume index vs. control, P = 0.040). With sustained pulmonary hypertension, RV hypertrophy (Fulton index P = 0.022) improved RV function at rest and during exercise, but this improvement was insufficient in CTEPH swine to result in an exercise-induced increase in cardiac index. In conclusion, embolization in combination with endothelial dysfunction results in CTEPH in swine. Exercise increased RV afterload, exacerbated the V/Q mismatch, and unmasked RV dysfunction. NEW & NOTEWORTHY Here, we present the first double-hit chronic thromboembolic pulmonary hypertension swine model. We show that embolization as well as endothelial dysfunction is required to induce sustained pulmonary hypertension, which is accompanied by altered exercise hemodynamics and an exacerbated ventilation/perfusion mismatch during exercise.

The small-molecule fast skeletal troponin activator, CK-2127107, improves exercise tolerance in a rat model of heart failure.

PubMed

Hwee, Darren T; Kennedy, Adam R; Hartman, James J; Ryans, Julie; Durham, Nickie; Malik, Fady I; Jasper, Jeffrey R

2015-04-01

Heart failure-mediated skeletal myopathy, which is characterized by muscle atrophy and muscle metabolism dysfunction, often manifests as dyspnea and limb muscle fatigue. We have previously demonstrated that increasing Ca(2+) sensitivity of the sarcomere by a small-molecule fast skeletal troponin activator improves skeletal muscle force and exercise performance in healthy rats and models of neuromuscular disease. The objective of this study was to investigate the effect of a novel fast skeletal troponin activator, CK-2127107 (2-aminoalkyl-5-N-heteroarylpyrimidine), on skeletal muscle function and exercise performance in rats exhibiting heart failure-mediated skeletal myopathy. Rats underwent a left anterior descending coronary artery ligation, resulting in myocardial infarction and a progressive decline in cardiac function [left anterior descending coronary artery heart failure (LAD-HF)]. Compared with sham-operated control rats, LAD-HF rat hindlimb and diaphragm muscles exhibited significant muscle atrophy. Fatigability was increased during repeated in situ isokinetic plantar flexor muscle contractions. CK-2127107 produced a leftward shift in the force-Ca(2+) relationship of skinned, single diaphragm, and extensor digitorum longus fibers. Exercise performance, which was assessed by rotarod running, was lower in vehicle-treated LAD-HF rats than in sham controls (116 ± 22 versus 193 ± 31 seconds, respectively; mean ± S.E.M.; P = 0.04). In the LAD-HF rats, a single oral dose of CK-2127107 (10 mg/kg p.o.) increased running time compared with vehicle treatment (283 ± 47 versus 116 ± 22 seconds; P = 0.0004). In summary, CK-2127107 substantially increases exercise performance in this heart failure model, suggesting that modulation of skeletal muscle function by a fast skeletal troponin activator may be a useful therapeutic in heart failure-associated exercise intolerance. Copyright © 2015 by The American Society for Pharmacology and Experimental Therapeutics.

Challenges with nitrate therapy and nitrate tolerance: prevalence, prevention, and clinical relevance.

PubMed

Thadani, Udho

2014-08-01

Nitrate therapy has been an effective treatment for ischemic heart disease for over 100 years. The anti-ischemic and exercise-promoting benefits of sublingually administered nitrates are well established. Nitroglycerin is indicated for the relief of an established attack of angina and for prophylactic use, but its effects are short lived. In an effort to increase the duration of beneficial effects, long-acting orally administered and topical applications of nitrates have been developed; however, following their continued or frequent daily use, patients soon develop tolerance to these long-acting nitrate preparations. Once tolerance develops, patients begin losing the protective effects of the long-acting nitrate therapy. By providing a nitrate-free interval, or declining nitrate levels at night, one can overcome or reduce the development of tolerance, but cannot provide 24-h anti-anginal and anti-ischemic protection. In addition, patients may be vulnerable to occurrence of rebound angina and myocardial ischemia during periods of absent nitrate levels at night and early hours of the morning, and worsening of exercise capacity prior to the morning dose of the medication. This has been a concern with nitroglycerin patches but not with oral formulations of isosorbide-5 mononitrates, and has not been adequately studied with isosorbide dinitrate. This paper describes problems associated with nitrate tolerance, reviews mechanisms by which nitrate tolerance and loss of efficacy develop, and presents strategies to avoid nitrate tolerance and maintain efficacy when using long-acting nitrate formulations.

Feasibility and Preliminary Efficacy of a 10-Week Resistance and Aerobic Exercise Intervention During Neoadjuvant Chemoradiation Treatment in Rectal Cancer Patients.

PubMed

Singh, Favil; Galvão, Daniel A; Newton, Robert U; Spry, Nigel A; Baker, Michael K; Taaffe, Dennis R

2018-06-01

Neoadjuvant chemoradiation treatment (CRT) in rectal cancer patients is associated with a reduction in physical capacity, lean mass and increased fatigue. As a countermeasure to these treatment-related adverse effects, we examined the feasibility and preliminary efficacy of a 10-week exercise program during CRT. Ten rectal cancer patients (7 men, aged 27-70 years, body mass index = 26.4 ± 3.8 kg/m 2 ) receiving CRT undertook supervised resistance and aerobic exercise twice weekly. Assessments were undertaken pre- and post-intervention for upper and lower body muscle strength by 1-RM, muscle endurance, physical performance tests, body composition by dual X-ray absorptiometry, quality of life, and fatigue. There was a significant loss in appendicular skeletal muscle (-1.1 kg, P = .012), and fat mass (-0.8 kg, P = .029) following CRT. Despite the loss in skeletal muscle, leg press ( P = .030) and leg extension ( P = .046) strength improved by 27.2% and 22.7%, respectively, and leg press endurance by 76.7% ( P = .007). Changes in strength were accompanied by improved performance ( P < .05) in 6-m fast walking speed (6.9%) and dynamic balance as determined by the 6-m backwards walk (15.5%). There was minimal change in quality of life and fatigue, and no adverse events related to training. Exercise during neoadjuvant CRT appears to be feasible and well tolerated in rectal cancer patients and may enhance physical function while minimizing adverse changes in body composition and cancer-related fatigue. These initial findings need to be confirmed in randomized controlled trials.

Effectiveness of a respiratory rehabilitation programme in patients with chronic obstructive pulmonary disease.

PubMed

Prunera-Pardell, María Jesús; Padín-López, Susana; Domenech-Del Rio, Adolfo; Godoy-Ramírez, Ana

To evaluate the effectiveness of the multidisciplinary respiratory rehabilitation (RR) programme in patients with severe or very severe chronic obstructive pulmonary disease pre the RR programme, at the end of the programme and one year after the RR, measuring changes in ability to exercise (walking test), effort tolerance(forced expiratory volume (FEV1)) and health-related quality of life. Quasi-experimental single group design. We included patients diagnosed with severe or very severe chronic obstructive pulmonary disease (stages III and IV of the GOLD classification) who entered the rehabilitation programme for the years 2011 and 2012. Demographic data, questionnaires on general health-related quality of life (SF-36) and specific to respiratory patients (St George's Respiratory Questionnaire), FEV1% and exercise capacity test (running test 6minutes) were collected. Data were collected before the RR programme, at the end of the RR programme and a year after completing the program. No significant differences in FEV1% values were observed. Regarding exercise capacity, an increase in distance walked in the walking test was noted, which changed significantly after training, 377±59.7 to 415±79 m after one year (P<.01). A statistically significant improvement in mean scores of HRQoL was observed, except for the emotional role dimension of the SF-36 questionnaire. A pulmonary rehabilitation programme for 8 weeks improved the exercise capacity, dyspnoea and quality of life of patients with severe and very severe chronic obstructive pulmonary disease. Copyright © 2017 Elsevier España, S.L.U. All rights reserved.

Cardiorespiratory function associated with dietary nitrate supplementation

PubMed Central

Bond, Vernon; Curry, Bryan H.; Adams, Richard G.; Millis, Richard M.; Haddad, Georges E.

2014-01-01

The advent of medical nutrition therapy and nutritional physiology affords the opportunity to link diet to specific cardiovascular mechanisms, suggesting novel treatments for cardiovascular disease. This study tests the hypothesis that beetroot juice increases the plasma nitric oxide (NO) concentration, which is associated with improvements in cardiorespiratory function at rest and during submaximal aerobic exercise. The subjects were 12 healthy, young adult, normotensive African-American females, with a body mass of 61 ± 2 kg, body fat of 28% ± 4%, and peak oxygen consumption of 26 ± 3 mL·kg−1·min−1. The subjects were studied at rest and during cycle ergometer exercise at 40%, 60%, and 80% of peak oxygen consumption. Plasma NO concentration, respiratory quotient (RQ), minute ventilation, systolic and diastolic blood pressure (SBP and DBP), heart rate, and oxygen consumption were compared between isocaloric, isovolumetric placebo control orange juice and experimental beetroot juice treatments on separate days. The beetroot juice treatment increased plasma NO concentration and decreased oxygen consumption, SBP, and the heart rate-SBP product at rest and at 40%, 60%, and 80% of peak oxygen consumption in the absence of significant effects on RQ, minute ventilation, heart rate, and DBP. These findings suggest that, in healthy subjects, beetroot juice treatments increase plasma NO concentration and decrease cardiac afterload and myocardial oxygen demand at rest and during 3 submaximal levels of aerobic exercise. Future studies should determine the cellular and molecular mechanisms responsible for the improvement in cardiorespiratory function associated with dietary nitrate supplementation and whether they translate into better cardiovascular function and exercise tolerance in individuals with a compromised cardiovascular system. PMID:24476472

A practical review for cardiac rehabilitation professionals of continuous-flow left ventricular assist devices: historical and current perspectives.

PubMed

Compostella, Leonida; Russo, Nicola; Setzu, Tiziana; Bottio, Tomaso; Compostella, Caterina; Tarzia, Vincenzo; Livi, Ugolino; Gerosa, Gino; Iliceto, Sabino; Bellotto, Fabio

2015-01-01

An increasing number of patients with end-stage heart failure are being treated with continuous-flow left ventricular assist devices (cf-LVADs). These patients provide new challenges to the staff in exercise-based cardiac rehabilitation (CR) programs. Even though experience remains limited, it seems that patients supported by cf-LVADs may safely engage in typical rehabilitative activities, provided that some attention is paid to specific aspects, such as the presence of a short external drive line. In spite of initial physical deconditioning, CR allows progressive improvement of symptoms such as fatigue and dyspnea. Intensity of rehabilitative activities should ideally be based on measured aerobic capacity and increased appropriately over time. Regular, long-term exercise training results in improved physical fitness and survival rates. Appropriate adjustment of cf-LVAD settings, together with maintenance of adequate blood volume, provides maximal output, while avoiding suction effects. Ventricular arrhythmias, although not necessarily constituting an immediate life-threatening situation, deserve treatment as they could lead to an increased rate of hospitalization and poorer quality of life. Atrial fibrillation may worsen symptoms of right ventricular failure and reduce exercise tolerance. Blood pressure measurements are possible in cf-LVAD patients only using a Doppler technique, and a mean blood pressure ≤80 mmHg is considered "ideal." Some patients may present with orthostatic intolerance, related to autonomic dysfunction. While exercise training constitutes the basic rehabilitative tool, a comprehensive intervention that includes psychological and social support could better meet the complex needs of patients in which cf-LVAD may offer prolonged survival.

Importance of compensatory heart rate increase during myocardial ischemia to preserve appropriate oxygen kinetics.

PubMed

Yoshida, Sadamitsu; Adachi, Hitoshi; Murata, Makoto; Tomono, Junichi; Oshima, Shigeru; Kurabayashi, Masahiko

2017-09-01

Myocardial ischemia induces cardiac dysfunction, resulting in insufficient oxygen supply to peripheral tissues and mismatched energy production during exercise. To relieve the insufficient oxygen supply, heart rate (HR) response is augmented; however, beta-adrenergic receptor blockers (BB) restrict HR response. Although BB are essential drugs for angina pectoris, the effect of BB on exercise tolerance in patients with angina has not been studied. The aim of this study was to clarify the importance of HR augmentation to preserve exercise tolerance in patients with angina pectoris. Forty-two subjects who underwent cardiopulmonary exercise testing (CPX) to detect myocardial ischemia were enrolled. CPX was performed until exhaustion or onset of significant myocardial ischemia using a ramp protocol. Subjects were assigned to three groups (Group A: with ST depression during CPX with significant coronary stenosis and taking BB; Group B: with ST depression and not taking BB; Group C: without ST depression and not taking BB). HR response to exercise was evaluated during the following two periods: below and above ischemic threshold (IT). In Group C, it was evaluated during the first 2min and the last 2min of a ramp exercise. No significant differences were observed among the three groups with regard to patients' basic characteristics. Below IT, there were no differences in oxygen pulse/watt (O 2 pulse increasing rate), HR/watt (ΔHR/ΔWR), and ΔV˙O 2 /ΔWR. Above IT, O 2 pulse increasing rate was greater in Group A than in Group B. ΔHR/ΔWR was smaller in Group A than in Group B. ΔV˙O 2 /ΔWR became smaller in Group A than in Group B. There was no difference in anaerobic threshold, and peak V˙O 2 was smaller in Group A than in Group B. Restriction of HR response by a BB is shown to be one of the important factors in diminished exercise tolerance. Copyright © 2016 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

High-intensity interval training in patients with coronary heart disease: Prescription models and perspectives.

PubMed

Ribeiro, Paula A B; Boidin, Maxime; Juneau, Martin; Nigam, Anil; Gayda, Mathieu

2017-01-01

Recently, high-intensity interval training (HIIT) has emerged as an alternative and/or complementary exercise modality to continuous aerobic exercise training (CAET) in CHD patients. However, the literature contains descriptions of many HIIT protocols with different stage durations, nature of recovery and intensities. In this review, we discuss the most recent forms of validated HIIT protocols in patients with coronary heart disease (CHD) and how to prescribe and use them during short- and long-term (phase II and III) cardiac rehabilitation programs. We also compare the superior and/or equivalent short- and long-term effects of HIIT versus CAET on aerobic fitness, cardiovascular function, and quality of life; their efficiency, safety, and tolerance; and exercise adherence. Short interval HIIT was found beneficial for CHD patients with lower aerobic fitness and would ideally be used in initiation and improvement stages. Medium and/or long interval HIIT protocols may be beneficial for CHD patients with higher aerobic fitness, and would be ideally used in the improvement and maintenance stages because of their high physiological stimulus. Finally, we propose progressive individualized models of HIIT programs (phase II to III) for patients with CHD and how to ideally use them according to the clinical status of patients and phase of the cardiac rehabilitation program. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Aerobic exercise training for adults with fibromyalgia.

PubMed

Bidonde, Julia; Busch, Angela J; Schachter, Candice L; Overend, Tom J; Kim, Soo Y; Góes, Suelen M; Boden, Catherine; Foulds, Heather Ja

2017-06-21

Exercise training is commonly recommended for individuals with fibromyalgia. This review is one of a series of reviews about exercise training for people with fibromyalgia that will replace the "Exercise for treating fibromyalgia syndrome" review first published in 2002. • To evaluate the benefits and harms of aerobic exercise training for adults with fibromyalgia• To assess the following specific comparisons ० Aerobic versus control conditions (eg, treatment as usual, wait list control, physical activity as usual) ० Aerobic versus aerobic interventions (eg, running vs brisk walking) ० Aerobic versus non-exercise interventions (eg, medications, education) We did not assess specific comparisons involving aerobic exercise versus other exercise interventions (eg, resistance exercise, aquatic exercise, flexibility exercise, mixed exercise). Other systematic reviews have examined or will examine these comparisons (Bidonde 2014; Busch 2013). We searched the Cochrane Library, MEDLINE, Embase, the Cumulative Index to Nursing and Allied Health Literature (CINAHL), the Physiotherapy Evidence Database (PEDro), Thesis and Dissertation Abstracts, the Allied and Complementary Medicine Database (AMED), the World Health Organization International Clinical Trials Registry Platform (WHO ICTRP), and the ClinicalTrials.gov registry up to June 2016, unrestricted by language, and we reviewed the reference lists of retrieved trials to identify potentially relevant trials. We included randomized controlled trials (RCTs) in adults with a diagnosis of fibromyalgia that compared aerobic training interventions (dynamic physical activity that increases breathing and heart rate to submaximal levels for a prolonged period) versus no exercise or another intervention. Major outcomes were health-related quality of life (HRQL), pain intensity, stiffness, fatigue, physical function, withdrawals, and adverse events. Two review authors independently selected trials for inclusion, extracted data, performed a risk of bias assessment, and assessed the quality of the body of evidence for major outcomes using the GRADE approach. We used a 15% threshold for calculation of clinically relevant differences between groups. We included 13 RCTs (839 people). Studies were at risk of selection, performance, and detection bias (owing to lack of blinding for self-reported outcomes) and had low risk of attrition and reporting bias. We prioritized the findings when aerobic exercise was compared with no exercise control and present them fully here.Eight trials (with 456 participants) provided low-quality evidence for pain intensity, fatigue, stiffness, and physical function; and moderate-quality evidence for withdrawals and HRQL at completion of the intervention (6 to 24 weeks). With the exception of withdrawals and adverse events, major outcome measures were self-reported and were expressed on a 0 to 100 scale (lower values are best, negative mean differences (MDs)/standardized mean differences (SMDs) indicate improvement). Effects for aerobic exercise versus control were as follows: HRQL: mean 56.08; five studies; N = 372; MD -7.89, 95% CI -13.23 to -2.55; absolute improvement of 8% (3% to 13%) and relative improvement of 15% (5% to 24%); pain intensity: mean 65.31; six studies; N = 351; MD -11.06, 95% CI -18.34 to -3.77; absolute improvement of 11% (95% CI 4% to 18%) and relative improvement of 18% (7% to 30%); stiffness: mean 69; one study; N = 143; MD -7.96, 95% CI -14.95 to -0.97; absolute difference in improvement of 8% (1% to 15%) and relative change in improvement of 11.4% (21.4% to 1.4%); physical function: mean 38.32; three studies; N = 246; MD -10.16, 95% CI -15.39 to -4.94; absolute change in improvement of 10% (15% to 5%) and relative change in improvement of 21.9% (33% to 11%); and fatigue: mean 68; three studies; N = 286; MD -6.48, 95% CI -14.33 to 1.38; absolute change in improvement of 6% (12% improvement to 0.3% worse) and relative change in improvement of 8% (16% improvement to 0.4% worse). Pooled analysis resulted in a risk ratio (RR) of moderate quality for withdrawals (17 per 100 and 20 per 100 in control and intervention groups, respectively; eight studies; N = 456; RR 1.25, 95%CI 0.89 to 1.77; absolute change of 5% more withdrawals with exercise (3% fewer to 12% more).Three trials provided low-quality evidence on long-term effects (24 to 208 weeks post intervention) and reported that benefits for pain and function persisted but did not for HRQL or fatigue. Withdrawals were similar, and investigators did not assess stiffness and adverse events.We are uncertain about the effects of one aerobic intervention versus another, as the evidence was of low to very low quality and was derived from single trials only, precluding meta-analyses. Similarly, we are uncertain of the effects of aerobic exercise over active controls (ie, education, three studies; stress management training, one study; medication, one study) owing to evidence of low to very low quality provided by single trials. Most studies did not measure adverse events; thus we are uncertain about the risk of adverse events associated with aerobic exercise. When compared with control, moderate-quality evidence indicates that aerobic exercise probably improves HRQL and all-cause withdrawal, and low-quality evidence suggests that aerobic exercise may slightly decrease pain intensity, may slightly improve physical function, and may lead to little difference in fatigue and stiffness. Three of the reported outcomes reached clinical significance (HRQL, physical function, and pain). Long-term effects of aerobic exercise may include little or no difference in pain, physical function, and all-cause withdrawal, and we are uncertain about long-term effects on remaining outcomes. We downgraded the evidence owing to the small number of included trials and participants across trials, and because of issues related to unclear and high risks of bias (performance, selection, and detection biases). Aerobic exercise appears to be well tolerated (similar withdrawal rates across groups), although evidence on adverse events is scarce, so we are uncertain about its safety.

Dropout from exercise randomized controlled trials among people with depression: A meta-analysis and meta regression.

PubMed

Stubbs, Brendon; Vancampfort, Davy; Rosenbaum, Simon; Ward, Philip B; Richards, Justin; Soundy, Andrew; Veronese, Nicola; Solmi, Marco; Schuch, Felipe B

2016-01-15

Exercise has established efficacy in improving depressive symptoms. Dropouts from randomized controlled trials (RCT's) pose a threat to the validity of this evidence base, with dropout rates varying across studies. We conducted a systematic review and meta-analysis to investigate the prevalence and predictors of dropout rates among adults with depression participating in exercise RCT's. Three authors identified RCT's from a recent Cochrane review and conducted updated searches of major electronic databases from 01/2013 to 08/2015. We included RCT's of exercise interventions in people with depression (including major depressive disorder (MDD) and depressive symptoms) that reported dropout rates. A random effects meta-analysis and meta regression were conducted. Overall, 40 RCT's were included reporting dropout rates across 52 exercise interventions including 1720 people with depression (49.1 years (range=19-76 years), 72% female (range=0-100)). The trim and fill adjusted prevalence of dropout across all studies was 18.1% (95%CI=15.0-21.8%) and 17.2% (95%CI=13.5-21.7, N=31) in MDD only. In MDD participants, higher baseline depressive symptoms (β=0.0409, 95%CI=0.0809-0.0009, P=0.04) predicted greater dropout, whilst supervised interventions delivered by physiotherapists (β=-1.2029, 95%CI=-2.0967 to -0.3091, p=0.008) and exercise physiologists (β=-1.3396, 95%CI=-2.4478 to -0.2313, p=0.01) predicted lower dropout. A comparative meta-analysis (N=29) established dropout was lower in exercise than control conditions (OR=0.642, 95%CI=0.43-0.95, p=0.02). Exercise is well tolerated by people with depression and drop out in RCT's is lower than control conditions. Thus, exercise is a feasible treatment, in particular when delivered by healthcare professionals with specific training in exercise prescription. Copyright © 2015 Elsevier B.V. All rights reserved.

Impact of Obesity on Cardiopulmonary Disease.

PubMed

Chandler, Marjorie L

2016-09-01

Although there are known detrimental effects of obesity on the heart and lungs, few data exist showing obesity as risk factor for cardiopulmonary disorders in dogs and cats. It is probable that increased abdominal fat is detrimental as it is in humans, and there is evidence of negative effects of increased intrathoracic fat. As well as physical effects of fat, increased inflammatory mediators and neurohormonal effects of obesity likely contribute to cardiopulmonary disorders. Weight loss in overweight individuals improves cardiac parameters and exercise tolerance. Obesity in patients with obstructive airway disorders is recognized to increase disease severity. Copyright © 2016 Elsevier Inc. All rights reserved.

Prevalence of exercise dependence and other behavioral addictions among clients of a Parisian fitness room.

PubMed

Lejoyeux, Michel; Avril, Marine; Richoux, Charlotte; Embouazza, Houcine; Nivoli, Fabrizia

2008-01-01

Exercise dependence is an inadequate pattern of exercise leading to clinically significant negative consequences. Subjects present loss of control of their physical activity, tolerance, and withdrawal symptoms when they do not practice sport. We studied the prevalence of exercise dependence among clients of a Parisian fitness room. We also assessed alcohol and nicotine use disorders, 2 other "socially tolerated" behavioral addictions (compulsive buying and Internet addiction), and 2 disorders related to anxiety focused on the body (bulimia and hypochondria). All clients of the fitness room 18 years and older were invited to participate in the study. Three hundred subjects were included; 125 (42%) presented diagnostic criteria of exercise dependence. Unsurprisingly, exercise dependents spent more hours each day in the fitness center practicing (2.1 vs 1.5 hours per day). They went to the fitness center more often each week (3.5 vs 2.9 days per week). Exercise addicts smoked less; alcohol consumption was equivalent in both groups. Compulsive buying was significantly more frequent in exercise dependents (63% vs 38%), which means they scored higher in the compulsive buying scale (5.4 vs 4.1). Prevalence of hypochondria was equivalent in both groups, but scores in the Whiteley Index of Hypochondria were higher (4.1 vs 3) in the exercise-dependent group. Bulimia was significantly more frequent among exercise dependents (70% vs 47%), who also presented a higher number of bulimic episodes each week (2.5 vs 1.3). Subjects with exercise dependence spent more time on their computer each day (3.9 vs 2.4 hours per day). We found no difference regarding time spent using Internet, the number of e-mails sent or received, and their time at speaking on a cellular phone. Our results lead to systematically study the addictive relation to exercise among regular clients of the fitness rooms. Exercise addicts are exposed to negative consequences for their excess of physical activity. Exercise addiction is also associated to compulsive buying, bulimia, and, in a lesser extent, hypochondria.

Effect of exercise on the pseudodiabetes of bed rest

NASA Technical Reports Server (NTRS)

Greenleaf, J. E.

1982-01-01

The effect of intensive isotonic exercise and isometric exercise (with its low metabolic rate) during bed rest on plasma insulin and glucose tolerance test was investigated. The subjects were seven healthy men, 19 to 22 years in age, 166 to 188 cm in height, and 62.40 to 103.80 kg in weight; maximal oxygen uptakes ranged from 3.36 to 4.38 liters/min. It appears that bed-rest-induced glucose intolerance is diminished with increasing energy expenditure during both bed rest and recovery.

[The effectiveness of fenspiride in the treatment of patients with chronic obstructive pulmonary disease].

PubMed

Butorov, S I; Muntianu, V I

2007-01-01

The purpose of the study was to assess the effectiveness and safety of long-term application of fenspiride, an anti-inflammatory drug, in patients with chronic obstructive pulmonary disease (COPD) under outpatient conditions. The drug was studied on 24 COPD patients. Fenspiride application resulted in improvement in bronchoobstructive syndrome and external respiration parameters, as well as a significant increase in exercise tolerance. In patients with stable stage I COPD, the use of fenspiride as a part of therapeutic regimen leads to better clinical results than in stage II patients. Long-term application of fenspiride in medium therapeutic doses under outpatient conditions is associated with positive clinical effects and leads to significant improvement in quality of life.

Treatment of Medial Tibial Stress Syndrome according to the Fascial Distortion Model: A Prospective Case Control Study

PubMed Central

Finze, Susanne; Lison, Andreas

2014-01-01

Medial tibial stress syndrome (MTSS) is a common problem among athletes and soldiers. There is no proven theory that could explain the pathophysiology of shin splints. The therapies described so far are time-consuming and involve a high risk of relapse. The method according to the fascial distortion model (FDM) addresses local changes in the area of the lower leg fascia. It is suited to reduce pain and functional impairments associated with this symptom complex by applying targeted manual techniques. 32 patients (male: 30; female: 2) participated in this study. Visual analogue scale (VAS) was used for the quantification of pain. Scores were also given to rate the maximum painless exercise tolerance of the patients. Subsequently treatment of the crural fascia was performed. Patients retested ability of running and jumping. Therapy was continued until full exercise tolerance or painlessness was reached. A significant reduction of the VAS pain score from 5.2 to 1.1 could be achieved (P < 0.001). The impairment of exercise tolerance could be reduced from 7 to 2 points (P < 0.001). The duration of treatment was 6.3 (SD: 4.3) days on average. The FDM therapy is a potential effective method for acute treatment of MTSS. PMID:25379543

Exercise Prevents Enhanced Postoperative Neuroinflammation and Cognitive Decline and Rectifies the Gut Microbiome in a Rat Model of Metabolic Syndrome.

PubMed

Feng, Xiaomei; Uchida, Yosuke; Koch, Lauren; Britton, Steve; Hu, Jun; Lutrin, David; Maze, Mervyn

2017-01-01

Postoperative cognitive decline (PCD) can affect in excess of 10% of surgical patients and can be considerably higher with risk factors including advanced age, perioperative infection, and metabolic conditions such as obesity and insulin resistance. To define underlying pathophysiologic processes, we used animal models including a rat model of metabolic syndrome generated by breeding for a trait of low aerobic exercise tolerance. After 35 generations, the low capacity runner (LCR) rats differ 10-fold in their aerobic exercise capacity from high capacity runner (HCR) rats. The LCR rats respond to surgical procedure with an abnormal phenotype consisting of exaggerated and persistent PCD and failure to resolve neuroinflammation. We determined whether preoperative exercise can rectify the abnormal surgical phenotype. Following institutional approval of the protocol each of male LCR and male HCR rats were randomly assigned to four groups and subjected to isoflurane anesthesia and tibia fracture with internal fixation (surgery) or anesthesia alone (sham surgery) and to a preoperative exercise regimen that involved walking for 10 km on a treadmill over 6 weeks (exercise) or being placed on a stationary treadmill (no exercise). Feces were collected before and after exercise for assessment of gut microbiome. Three days following surgery or sham surgery the rats were tested for ability to recall a contextual aversive stimulus in a trace fear conditioning paradigm. Thereafter some rats were euthanized and the hippocampus harvested for analysis of inflammatory mediators. At 3 months, the remainder of the rats were tested for memory recall by the probe test in a Morris Water Maze. Postoperatively, LCR rats exhibited exaggerated cognitive decline both at 3 days and at 3 months that was prevented by preoperative exercise. Similarly, LCR rats had excessive postoperative neuroinflammation that was normalized by preoperative exercise. Diversity of the gut microbiome in the LCR rats improved after exercise. Preoperative exercise eliminated the metabolic syndrome risk for the abnormal surgical phenotype and was associated with a more diverse gut microbiome. Prehabilitation with exercise should be considered as a possible intervention to prevent exaggerated and persistent PCD in high-risk settings.

The Effects of 3 Weeks of Uphill and Downhill Walking on Blood Lipids and Glucose Metabolism in Pre-Diabetic Men: A Pilot Study.

PubMed

Philippe, Marc; Gatterer, Hannes; Eder, Erika Maria; Dzien, Alexander; Somavilla, Matthias; Melmer, Andreas; Ebenbichler, Christoph; Müller, Tom; Burtscher, Martin

2017-03-01

The prevention of type 2 diabetes in persons at risk for diabetes is of utmost importance. Physical activity in general and even exercises at moderate intensities such as walking significantly reduce the risk of the development of type 2 diabetes. However, it is still a matter of debate whether lipids and glucose metabolism are differently affected by regular concentric (e.g., uphill walking) and eccentric (e.g., downhill walking) endurance exercise. The aim of this study was to investigate the effects of short-term (3 weeks) uphill and downhill walking on glucose metabolism and blood lipids in pre-diabetic middle-aged men in a real world setting. The study was designed as an investigator-initiated 2 group random selection pre-test post-test trial. Sixteen pre-diabetic men (age: 56.9 ± 5.1 years; BMI: 28.1 ± 2.3 kg·m -2 ) performed 9 uphill (n = 8) or 9 downhill (n = 8) walking sessions within 3 weeks. The primary outcomes were the markers of glucose metabolism and blood lipids measured before and after the training period. After uphill walking glucose tolerance (area under the curve of the oral glucose tolerance test: -43.25 ± 53.12 mg·dl -1 ; p = 0.05; effect size: 0.81), triglycerides (-48.75 ± 54.49 mg·dl -1 ; p = 0.036; effect size: 0.89), HDL-C (+7.86 ± 9.54 mg·dl -1 ; p = 0.05; effect size: 0.82) and total cholesterol/HDL-C ratio (-0.58 ± 0.41; p = 0.012; effect size: 1.39) had significantly improved. No significant metabolic adaptations were found after downhill walking. However, when adjusted for estimated energy expenditure, uphill and downhill walking had equal effects on almost all metabolic parameters. Moreover, the magnitude of the baseline impairments of glucose tolerance was significantly related to the extent of change in both groups. Depending on the fitness level and individual preferences both types of exercise may be useful for the prevention of type 2 diabetes and disorders in lipid metabolism.

Effects of lemon verbena extract (Recoverben®) supplementation on muscle strength and recovery after exhaustive exercise: a randomized, placebo-controlled trial.

PubMed

Buchwald-Werner, Sybille; Naka, Ioanna; Wilhelm, Manfred; Schütz, Elivra; Schoen, Christiane; Reule, Claudia

2018-01-01

Exhaustive exercise causes muscle damage accompanied by oxidative stress and inflammation leading to muscle fatigue and muscle soreness. Lemon verbena leaves, commonly used as tea and refreshing beverage, demonstrated antioxidant and anti-inflammatory properties. The aim of this study was to investigate the effects of a proprietary lemon verbena extract (Recoverben®) on muscle strength and recovery after exhaustive exercise in comparison to a placebo product. The study was performed as a randomized, placebo-controlled, double-blind study with parallel design. Forty-four healthy males and females, which were 22-50 years old and active in sports, were randomized to 400 mg lemon verbena extract once daily or placebo. The 15 days intervention was divided into 10 days supplementation prior to the exhaustive exercise day (intensive jump-protocol), one day during the test and four days after. Muscle strength (MVC), muscle damage (CK), oxidative stress (GPx), inflammation (IL6) and volunteer-reported muscle soreness intensity were assessed pre and post exercise. Participants in the lemon verbena group benefited from less muscle damage as well as faster and full recovery. Compared to placebo, lemon verbena extract receiving participants had significantly less exercise-related loss of muscle strength ( p  = 0.0311) over all timepoints, improved glutathione peroxidase activity by trend ( p  = 0.0681) and less movement induced pain ( p  = 0.0788) by trend. Creatine kinase and IL-6 didn't show significant discrimmination between groups. Lemon verbena extract (Recoverben®) has been shown to be a safe and well-tolerated natural sports ingredient, by reducing muscle damage after exhaustive exercise. The trial was registered in the clinical trials registry (clinical trial.gov NCT02923102). Registered 28 September 2016.

Assessment of Aerobic Exercise Adverse Effects during COPD Exacerbation Hospitalization

PubMed Central

Mesquita, Carolina Bonfanti; Caram, Laura M. O.; Dourado, Victor Zuniga; de Godoy, Irma; Tanni, Suzana Erico

2017-01-01

Introduction. Aerobic exercise performed after hospital discharge for exacerbated COPD patients is already recommended to improve respiratory and skeletal muscle strength, increase tolerance to activity, and reduce the sensation of dyspnea. Previous studies have shown that anaerobic activity can clinically benefit patients hospitalized with exacerbated COPD. However, there is little information on the feasibility and safety of aerobic physical activity performed by patients with exacerbated COPD during hospitalization. Objective. To evaluate the effects of aerobic exercise on vital signs in hospitalized patients with exacerbated COPD. Patients and Methods. Eleven COPD patients (63% female, FEV1: 34.2 ± 13.9% and age: 65 ± 11 years) agreed to participate. Aerobic exercise was initiated 72 hours after admission on a treadmill; speed was obtained from the distance covered in a 6-minute walk test (6MWT). Vital signs were assessed before and after exercise. Results. During the activity systolic blood pressure increased from 125.2 ± 13.6 to 135.8 ± 15.0 mmHg (p = 0.004) and respiratory rate from 20.9 ± 4.4 to 24.2 ± 4.5 rpm (p = 0.008) and pulse oximetry (SpO2) decreased from 93.8 ± 2.3 to 88.5 ± 5.7% (p < 0.001). Aerobic activity was considered intense, heart rate ranged from 99.2 ± 11.5 to 119.1 ± 11.1 bpm at the end of exercise (p = 0.092), and patients reached on average 76% of maximum heart rate. Conclusion. Aerobic exercise conducted after 72 hours of hospitalization in patients with exacerbated COPD appears to be safe. PMID:28265180

Locomotion Mode Affects the Physiological Strain during Exercise at Walk-Run Transition Speed inElderly Men.

PubMed

Freire, Raul; Farinatti, Paulo; Cunha, Felipe; Silva, Brenno; Monteiro, Walace

2017-07-01

This study investigated cardiorespiratory responses and rating of perceived exertion (RPE) during prolonged walking and running exercise performed at the walk-run transition speed (WRTS) in untrained healthy elderly men. 20 volunteers (mean±SE, age: 68.4±1.2 yrs; height: 170.0±0.02 cm; body mass: 74.7±2.3 kg) performed the following bouts of exercise: a) maximal cardiopulmonary exercise test (CPET); b) specific protocol to detect WRTS; and c) two 30-min walking and running bouts at WRTS. Expired gases were collected during exercise bouts via the Ultima CardiO 2 metabolic analyzer. Compared to walking, running at the WRTS resulted in higher oxygen uptake (>0.27 L·min -1 ), pulmonary ventilation (>7.7 L·min -1 ), carbon dioxide output (>0.23 L·min -1 ), heart rate (>15 beats·min -1 ), oxygen pulse (>0.88 15 mL·beats -1 ), energy expenditure (>27 kcal) and cost of oxygen transport (>43 mL·kg -1 ·km -1 ·bout -1 ). The increase of overall and local RPEs with exercise duration was similar across locomotion modes (P<0.001). In all participants, %HRR and %VO 2 R throughout walking and running bouts were around or above the gas exchange threshold. In conclusion, elderly men exhibited higher cardiorespiratory responses during 30-min bouts of running than walking at WRTS. Nevertheless, walking corresponded to relative metabolic intensities compatible with preservation or improvement of cardiorespiratory fitness and should be preferable over running at WRTS in the untrained elderly characterized by poor fitness and reduced exercise tolerance. © Georg Thieme Verlag KG Stuttgart · New York.

AT1 and aldosterone receptors blockade prevents the chronic effect of nandrolone on the exercise-induced cardioprotection in perfused rat heart subjected to ischemia and reperfusion.

PubMed

Marques-Neto, Silvio Rodrigues; Ferraz, Emanuelle Baptista; Rodrigues, Deivid Carvalho; Njaine, Brian; Rondinelli, Edson; Campos de Carvalho, Antônio Carlos; Nascimento, Jose Hamilton Matheus

2014-04-01

Myocardial tolerance to ischaemia/reperfusion (I/R) injury is improved by exercise training, but this cardioprotection is impaired by the chronic use of anabolic androgenic steroids (AAS). The present study evaluated whether blockade of angiotensin II receptor (AT1-R) with losartan and aldosterone receptor (mineralocorticoid receptor, MR) with spironolactone could prevent the deleterious effect of AAS on the exercise-induced cardioprotection. Male Wistar rats were exercised and treated with either vehicle, nandrolone decanoate (10 mg/kg/week i.m.) or the same dose of nandrolone plus losartan or spironolactone (20 mg/kg/day orally) for 8 weeks. Langendorff-perfused hearts were subjected to I/R and evaluated for the postischaemic recovery of left ventricle (LV) function and infarct size. mRNA and protein expression of angiotensin II type 1 receptor (AT1-R), mineralocorticoid receptor (MR), and KATP channels were determined by reverse-transcriptase polymerase chain reaction and Western blotting. Postischaemic recovery of LV function was better and infarct size was smaller in the exercised rat hearts than in the sedentary rat hearts. Nandrolone impaired the exercise-induced cardioprotection, but this effect was prevented by losartan (AT1-R antagonist) and spironolactone (MR antagonist) treatments. Myocardial AT1-R and MR expression levels were increased, and the expression of the KATP channel subunits SUR2a and Kir6.1 was decreased and Kir6.2 increased in the nandrolone-treated rat hearts. The nandrolone-induced changes of AT1-R, MR, and KATP subunits expression was normalized by the losartan and spironolactone treatments. The chronic nandrolone treatment impairs the exercise-induced cardioprotection against ischaemia/reperfusion injury by activating the cardiac renin-angiotensin-aldosterone system and downregulating KATP channel expression.

Modeling the Fault Tolerant Capability of a Flight Control System: An Exercise in SCR Specification

NASA Technical Reports Server (NTRS)

Alexander, Chris; Cortellessa, Vittorio; DelGobbo, Diego; Mili, Ali; Napolitano, Marcello

2000-01-01

In life-critical and mission-critical applications, it is important to make provisions for a wide range of contingencies, by providing means for fault tolerance. In this paper, we discuss the specification of a flight control system that is fault tolerant with respect to sensor faults. Redundancy is provided by analytical relations that hold between sensor readings; depending on the conditions, this redundancy can be used to detect, identify and accommodate sensor faults.

Effect of vaginal spheres and pelvic floor muscle training in women with urinary incontinence: a randomized, controlled trial.

PubMed

Porta-Roda, Oriol; Vara-Paniagua, Jesús; Díaz-López, Miguel A; Sobrado-Lozano, Pilar; Simó-González, Marta; Díaz-Bellido, Paloma; Reula-Blasco, María C; Muñoz-Garrido, Francisco

2015-08-01

To compare the efficacy and safety of Kegel exercises performed with or without, vaginal spheres as treatment for women with urinary incontinence. Multicentre parallel-group, open, randomized controlled trial. Women were allocated to either a pelvic floor muscle-training program consisting of Kegel exercises performed twice daily, 5 days/week at home, over 6 months with vaginal spheres, or to the same program without spheres. The primary endpoint was women's report of urinary incontinence at 6 months using the International Consultation on Incontinence Questionnaire-Short Form (ICIQ-UI-SF). Secondary outcome measures were the 1 hr pad-test, King's Health Questionnaire (KHQ) and a five-point Likert scale for subjective evaluation. Adherence was measured with the Morisky-Green test. Thirty-seven women were randomized to the spheres group and 33 to the control group. The primary endpoint was evaluated in 65 women (35 in the spheres group vs. 30 controls). ICIQ-UI-SF results improved significantly at 1-month follow-up in the spheres group (P < 0.01) and at 6 months in the controls. The 1 hr pad-test improved in the spheres group but not in the control group. No significant differences were found in the KHQ results or in the subjective evaluation of efficacy and safety. Adherence was higher in the spheres group but differences were not significant. Mild transient side effects were reported in four patients in the spheres group and one in the control group. Both treatments improved urinary incontinence but women who performed the exercises with vaginal spheres showed an earlier improvement. Vaginal spheres were well tolerated and safe. © 2014 Wiley Periodicals, Inc.

High-intensity interval training (swimming) significantly improves the adverse metabolism and comorbidities in diet-induced obese mice.

PubMed

Motta, Victor F; Aguila, Marcia B; Mandarim-DE-Lacerda, Carlos A

2016-05-01

Controlling obesity and other comorbidities in the population is a challenge in modern society. High-intensity interval training (HIIT) combines short periods of high-intensity exercise with long recovery periods or a low-intensity exercise. The aim was to assess the impact of HIIT in the context of diet-induced obesity in the animal model. C57BL/6 mice were fed one of the two diets: standard chow (lean group [LE]) or a high-fat diet (obese group [OB]). After twelve weeks, the animals were divided into non-trained groups (LE-NT and OB-NT) and trained groups (LE-T and OB-T), and began an exercise protocol. For biochemical analysis of inflammatory and lipid profile, we used a colorimetric enzymatic method and an automatic spectrophotometer. One-way ANOVA was used for statistical analysis of the experimental groups with Holm-Sidak post-hoc Test. Two-way ANOVA analyzed the interactions between diet and HIIT protocol. HIIT leads to significant reductions in body mass, blood glucose, glucose tolerance and hepatic lipid profile in T-groups compared to NT-groups. HIIT was able to reduce plasma levels of inflammatory cytokines. Additionally, HIIT improves the insulin immunodensity in the islets, reduces the adiposity and the hepatic steatosis in the T-groups. HIIT improves beta-oxidation and peroxisome proliferator-activated receptor (PPAR)-alpha and reduces lipogenesis and PPAR-gamma levels in the liver. In skeletal muscle, HIIT improves PPAR-alpha and glucose transporter-4 and reduces PPAR-gamma levels. HIIT leads to attenuate the adverse effects caused by a chronic ingestion of a high-fat diet.

High-intensity interval training (swimming) significantly improves the adverse metabolism and comorbidities in diet-induced obese mice.

PubMed

Motta, V F; Aguila, M B; Mandarim-De-Lacerda, C A

2015-02-10

Controlling obesity and other comorbidities in the population is a challenge in modern society. High-intensity interval training (HIIT) combines short periods of high-intensity exercise with long recovery periods or a low-intensity exercise. The aim was to assess the impact of HIIT in the context of diet-induced obesity in the animal model. C57BL/6 mice were fed one of the two diets: standard chow (Lean group - LE) or a high--fat diet (Obese group - OB). After twelve weeks, the animals were divided into non-trained groups (LE--NT and OB-NT) and trained groups (LE-T and OB--T), and began an exercise protocol. For biochemical analysis of inflammatory and lipid profile, we used a colorimetric enzymatic method and an automatic spectrophotometer. One-way ANOVA was used for statistical analysis of the experimental groups with Holm-Sidak pos hoc test. Two-way ANOVA analyzed the interactions between diet and HIIT protocol. HIIT leads to significant reductions in body mass, blood glucose, glucose tolerance and hepatic lipid profile in T-groups compared to NT-groups. HIIT was able to reduce plasma levels of inflammatory cytokines. Additionally, HIIT improves the insulin immunodensity in the islets, reduces the adiposity and the hepatic steatosis in the T-groups. HIIT improves beta--oxidation and peroxisome proliferator--activated receptor (PPAR)-alpha and reduces lipogenesis and PPAR--gamma levels in the liver. In skeletal muscle, HIIT improves PPAR--alpha and glucose transporter-4 and reduces PPAR--gamma levels. HIIT leads to attenuate the adverse effects caused by a chronic ingestion of a high-fat diet.

Does training-induced orthostatic hypotension result from reduced carotid baroreflex responsiveness?

NASA Technical Reports Server (NTRS)

Pawelczyk, James A.; Raven, Peter B.

1994-01-01

As manned space travel has steadily increased in duration and sophistication, the answer to a simple, relevant question remains elusive. Does endurance exercise training - high intensity rhythmic activity, performed regularly for extended periods of time - alter the disposition to, or severity of, postflight orthostatic hypotension? Research results continue to provide different views; however, data are difficult to compare because of the following factors that vary between investigations: the type of orthostatic stress imposed (+Gz, lower body negative pressure (LBNP), head-up tilt); pretest perturbations used (exercise, heat exposure, head-down tilting, bed rest, water immersion, hypohydration, pharmacologically-induced diuresis); the length of the training program used in longitudinal investigations (days versus weeks versus months); the criteria used to define fitness; and the criteria used to define orthostatic tolerance. Generally, research results indicate that individuals engaged in aerobic exercise activities for a period of years have been reported to have reduced orthostatic tolerance compared to untrained control subjects, while the results of shorter term longitudinal studies remain equivocal. Such conclusions suggest that chronic athletic training programs reduce orthostatic tolerance, whereas relatively brief (days to weeks) training programs do not affect orthostatic tolerance to any significant degree (increase or decrease). A primary objective was established to identify the alterations in blood pressure control that contribute to training-induced orthostatic hypotension (TIOH). Although any aspect of blood pressure regulation is suspect, current research has been focused on the baroreceptor system. Reductions in carotid baroreflex responsiveness have been documented in exercise-trained rabbits, reportedly due to an inhibitory influence from cardiac afferent, presumably vagal, nerve fibers that is abolished with intrapericardiac denervation. The purpose of this investigation was to attempt to determine if similar relationships existed in men with varied levels of fitness, using maximal aerobic power, VO2 max, as the marker of fitness.

The Effects of Acute Interval Exercise and Strawberry Intake on Postprandial Lipemia.

PubMed

O'Doherty, Alasdair F; Jones, Huw S; Sathyapalan, Thozhukat; Ingle, Lee; Carroll, Sean

2017-11-01

Raised postprandial triglycerides (TAG) and related oxidative stresses are strongly associated with increased cardiovascular disease risk. Acute exercise and strawberry ingestion independently ameliorate postprandial lipid excursions and oxidative stress. However, the combined effects of these lifestyle interventions are unknown. We investigated whether acute exercise and strawberry consumption improved postprandial responses to an oral fat tolerance test (OFTT) in overweight/obese males. Overweight/obese adult males underwent four separate OFTT (73 g fat, 33 g carbohydrate) with blood sampled at baseline and hourly for 4 h after OFTT. Two OFTT contained 25 g freeze-dried strawberries and two contained strawberry flavoring (placebo). Participants performed 40 min of submaximal high-intensity interval cycling exercise 16 h before one strawberry and one placebo OFTT and rested before the remaining two OFTT. Serum TAG was analyzed, and TAG area under the curve (AUC) and incremental AUC (iAUC) were calculated. Oxidative stress markers were measured at baseline and 4 h. Differences between conditions (strawberry/placebo and exercise/rest) were assessed using repeated-measures ANOVA. Ten males (age = 31.5, interquartile range = 17.8 yr, body mass index = 29.9 ± 1.8 kg·m) completed the study. TAG AUC was 1.5 mmol per 4 h·L lower for the exercise conditions compared with the rest conditions (95% confidence interval [CI] = -2.3 to -0.8 mmol per 4 h·L, P = 0.001). TAG AUC was not different between strawberry and placebo conditions (95% CI = -1.3 to 0.6 mmol per 4 h·L, P = 0.475). TAG iAUC was 0.5 mmol per 4 h·L greater for the strawberry compared with the placebo conditions (95% CI = 0.1 to 1.0 mmol per 4 h·L, P = 0.021). There were no changes in markers of lipid related oxidative stress (P > 0.05). Acute submaximal high-intensity interval cycling exercise appears effective in reducing postprandial lipemia in overweight/obese adult males. However, strawberry ingestion did not improve postprandial TAG.

[Clinicofunctional condition and quality of life in patients with chronic obstructive pulmonary disease before and after outpatient treatment with fenspiride].

PubMed

Butorov, S I; Butorov, I V; Bodrug, N I; Krushka, S I; Tofan, E F

2008-01-01

To study effects of long-term administration of fenspiride in combination with broncholytic drugs on dynamics of clinical symptoms, external respiration function and quality of life in patients with chronic obstructive pulmonary disease (COPD). A comparative randomized trial of fenspiride used for 6 months in combination with broncholytic drugs enrolled 68 COPD patients. A clinical status, external respiration function were examined. Quality of life was evaluated with WHO questionnaire WHOQOL-100. Addition of fenspiride to combined treatment of COPD attenuates COPD symptoms, normalizes blood biochemistry, improves external respiration function, raises exercise tolerance. Quality of life improved by physical and mental state scales. Fenspiride addition to COPD treatment improves efficacy of the standard treatment and is recommended for treatment of COPD of stage I and II in combination with broncholytic drugs.

Epinephrine and the metabolic syndrome.

PubMed

Ziegler, Michael G; Elayan, Hamzeh; Milic, Milos; Sun, Ping; Gharaibeh, Munir

2012-02-01

Epinephrine is the prototypical stress hormone. Its stimulation of all α and β adrenergic receptors elicits short-term systolic hypertension, hyperglycemia, and other aspects of the metabolic syndrome. Acute epinephrine infusion increases cardiac output and induces insulin resistance, but removal of the adrenal medulla has no consistent effect on blood pressure. Epinephrine is the most effective endogenous agonist at the β2 receptor. Transgenic mice that cannot make epinephrine and mice that lack the β2 receptor become hypertensive during exercise, presumably owing to the absence of β2-mediated vasodilatation. Epinephrine-deficient mice also have cardiac remodeling and poor cardiac responses to stress, but do not develop resting hypertension. Mice that cannot make epinephrine have a normal metabolism on a regular 14% fat diet but become hyperglycemic and insulin resistant when they eat a high fat diet. Vigorous exercise prevents diabetes in young mice and humans that overeat. However, exercise is a less effective treatment in older type 2 human diabetics and had no effect on glucose or insulin responses in older, diabetic mice. Sensitivity of the β2 receptor falls sharply with advancing age, and adrenal epinephrine release also decreases. However, treatment of older diabetic mice with a β2 adrenergic agonist improved insulin sensitivity, indicating that β2 subsensitivity can be overcome pharmacologically. Recent studies show that over the long term, epinephrine prevents hypertension during stress and improves glucose tolerance. The hyperglycemic influence of epinephrine is short-lived. Chronic administration of epinephrine and other β2 agonists improves cellular glucose uptake and metabolism. Overall, epinephrine counteracts the metabolic syndrome.

Continuous Positive Airway Pressure During Exercise Improves Walking Time in Patients Undergoing Inpatient Cardiac Rehabilitation After Coronary Artery Bypass Graft Surgery: A RANDOMIZED CONTROLLED TRIAL.

PubMed

Pantoni, Camila Bianca Falasco; Di Thommazo-Luporini, Luciana; Mendes, Renata Gonçalves; Caruso, Flávia Cristina Rossi; Mezzalira, Daniel; Arena, Ross; Amaral-Neto, Othon; Catai, Aparecida Maria; Borghi-Silva, Audrey

2016-01-01

Continuous positive airway pressure (CPAP) has been used as an effective support to decrease the negative pulmonary effects of coronary artery bypass graft (CABG) surgery. However, it is unknown whether CPAP can positively influence patients undergoing CABG during exercise. This study evaluated the effectiveness of CPAP on the first day of ambulation after CABG in patients undergoing inpatient cardiac rehabilitation (CR). Fifty-four patients after CABG surgery were randomly assigned to receive either inpatient CR and CPAP (CPG) or standard CR without CPAP (CG). Cardiac rehabilitation included walking and CPAP pressures were set between 10 to 12 cmH2O. Participants were assessed on the first day of walking at rest and during walking. Outcome measures included breathing pattern variables, exercise time in seconds (ETs), dyspnea/leg effort ratings, and peripheral oxygen saturation (SpO2). Twenty-seven patients (13 CPG vs 14 CG) completed the study. Compared with walking without noninvasive ventilation assistance, CPAP increased ETs by 43.4 seconds (P = .040) during walking, promoted better thoracoabdominal coordination, increased ventilation during walking by 12.5 L/min (P = .001), increased SpO2 values at the end of walking by 2.6% (P = .016), and reduced dyspnea ratings by 1 point (P = .008). Continuous positive airway pressure can positively influence exercise tolerance, ventilatory function, and breathing pattern in response to a single bout of exercise after CABG.

Effects Of Exercise During Prolonged Bed Rest

NASA Technical Reports Server (NTRS)

Arnaud, S.; Berry, P; Cohen, M.; Danelis, J.; Deroshia, C.; Greenleaf, J.; Harris, B.; Keil, L.; Bernauer, E.; Bond, M.;

Sodium bicarbonate supplementation improves severe-intensity intermittent exercise under moderate acute hypoxic conditions.

PubMed

Deb, Sanjoy K; Gough, Lewis A; Sparks, S Andy; McNaughton, Lars R

2018-03-01

Acute moderate hypoxic exposure can substantially impair exercise performance, which occurs with a concurrent exacerbated rise in hydrogen cation (H + ) production. The purpose of this study was therefore, to alleviate this acidic stress through sodium bicarbonate (NaHCO 3 ) supplementation and determine the corresponding effects on severe-intensity intermittent exercise performance. Eleven recreationally active individuals participated in this randomised, double-blind, crossover study performed under acute normobaric hypoxic conditions (FiO 2 % = 14.5%). Pre-experimental trials involved the determination of time to attain peak bicarbonate anion concentrations ([HCO 3 - ]) following NaHCO 3 ingestion. The intermittent exercise tests involved repeated 60-s work in their severe-intensity domain and 30-s recovery at 20 W to exhaustion. Participants ingested either 0.3 g kg bm -1 of NaHCO 3 or a matched placebo of 0.21 g kg bm -1 of sodium chloride prior to exercise. Exercise tolerance (+ 110.9 ± 100.6 s; 95% CI 43.3-178 s; g = 1.0) and work performed in the severe-intensity domain (+ 5.8 ± 6.6 kJ; 95% CI 1.3-9.9 kJ; g = 0.8) were enhanced with NaHCO 3 supplementation. Furthermore, a larger post-exercise blood lactate concentration was reported in the experimental group (+ 4 ± 2.4 mmol l -1 ; 95% CI 2.2-5.9; g = 1.8), while blood [HCO 3 - ] and pH remained elevated in the NaHCO 3 condition throughout experimentation. In conclusion, this study reported a positive effect of NaHCO 3 under acute moderate hypoxic conditions during intermittent exercise and therefore, may offer an ergogenic strategy to mitigate hypoxic induced declines in exercise performance.

Effects of voluntary running exercise on bone histology in type 2 diabetic rats.

PubMed

Takamine, Yuri; Ichinoseki-Sekine, Noriko; Tsuzuki, Takamasa; Yoshihara, Toshinori; Naito, Hisashi

2018-01-01

The incidence of obesity in children and adolescents, which may lead to type 2 diabetes, is increasing. Exercise is recommended to prevent and improve diabetes. However, little is known about the bone marrow environment at the onset of diabetes in the young, and it is unclear whether exercise training is useful for maintaining bone homeostasis, such as mechanical and histological properties. Thus, this study clarified the histological properties of bone and whether exercise contributes to maintaining bone homeostasis at the onset of type 2 diabetes in rats. Four-week-old male Otsuka Long-Evans Tokushima Fatty (OLETF; n = 21) rats as a diabetic model and Long-Evans Tokushima Otsuka (LETO; n = 18) rats as a control were assigned randomly to four groups: the OLETF sedentary group (O-Sed; n = 11), OLETF exercise group (O-Ex; n = 10), LETO sedentary group (L-Sed; n = 9), and LETO exercise group (L-Ex; n = 9). All rats in the exercise group were allowed free access to a steel running wheel for 20 weeks (5-25 weeks of age). In the glucose tolerance test, blood glucose level was higher in the O-Sed group than that in the L-Sed and L-Ex groups, and was markedly suppressed by the voluntary running exercise of O-Ex rats. The energy to fracture and the two-dimensional bone volume at 25 weeks of age did not differ significantly among the groups, though the maximum breaking force and stiffness were lower in OLETF rats. However, bone marrow fat volume was greater in O-Sed than that in L-Sed and L-Ex rats, and was markedly suppressed by wheel running in the O-Ex rats. Our results indicate that exercise has beneficial effects not only for preventing diabetes but also on normal bone remodeling at an early age.

Incentive spirometry combined with expiratory positive airway pressure improves asthma control and quality of life in asthma: a randomised controlled trial.

PubMed

Rondinel, Tatiana Zacarias; Corrêa, Isadora Faraco; Hoscheidt, Luíza Machado; Bueno, Mirelle Hugo; Da Silva, Luciano Muller Corrêa; Reppold, Caroline Tozzi; Dal Lago, Pedro

2015-03-01

The use of the incentive spirometer (IS) and expiratory positive airway pressure (EPAP) provides several benefits in patients with respiratory disorders. However, the effects of the use of these devices coupled (IS + EPAP) are still unknown in asthmatic patients. The aim of this study was to evaluate the effect of IS associated with EPAP on exercise tolerance (six-minute walk test - 6MWT), lung function (by spirometry), asthma control (Asthma Control Questionnaire - ACQ) and quality of life (Asthma Quality of Life Questionnaire - AQLQ) in patients with severe asthma. Patients were randomised into two groups: IS + EPAP (n = 8) and control (n = 6). The IS + EPAP group performed breathing exercises at home, twice daily for 20 min, over a period of 5 weeks. There was no significant difference in spirometric variables and in the distance walked in the 6MWT in both groups. However, the IS + EPAP group showed an improvement in asthma control (p = 0.002) and quality of life (p = 0.02). These findings demonstrate that the IS + EPAP protocol, when performed at home, provides an improvement in asthma control and quality of life for patients with severe asthma when evaluated by ACQ and AQLQ, respectively.

Improving joint pain and function in osteoarthritis.

PubMed

Owens, Claire; Conaghan, Philip G

2016-12-01

Osteoarthritis has become a major chronic pain condition. It affects more than 10% of adults and accounts for almost 10% of health service resources. The impact of osteoarthritis is amplified by underuse of effective muscle strengthening exercises and a focus on often less effective and poorly tolerated analgesic therapies. Although traditionally considered to be primarily a disease of cartilage, there is now ample evidence that typical clinical osteoarthritis involves multiple tissue pathologies. Increased BMI is associated with a higher incidence of knee osteoarthritis. Anatomical abnormalities such as valgus alignment or previous joint trauma including meniscectomy, anterior cruciate ligament rupture and fracture through the joint are also associated with increased incidence of osteoarthritis. Pain is the main presenting symptom. However, we still have a poor understanding of the causes of pain in osteoarthritis. In patients aged 45 or over the diagnosis should be made clinically without investigations if the patient has activity-related joint pain in addition to early morning joint stiffness lasting less than 30 minutes. Muscle strengthening and aerobic exercise have been shown to improve joint pain and function. Weight loss not only improves joint pain and function but has a myriad of other health benefits, reducing the incidence of lifestyle associated diseases such as cardiovascular disease and type 2 diabetes, and mechanical stress on the joints.

The effects of coenzyme Q10 treatment on maternally inherited diabetes mellitus and deafness, and mitochondrial DNA 3243 (A to G) mutation.

PubMed

Suzuki, S; Hinokio, Y; Ohtomo, M; Hirai, M; Hirai, A; Chiba, M; Kasuga, S; Satoh, Y; Akai, H; Toyota, T

1998-05-01

The characteristic clinical features of diabetes mellitus with mitochondrial DNA (mtDNA) 3243(A-G) mutation are progressive insulin secretory defect, neurosensory deafness and maternal inheritance, referred to as maternally inherited diabetes mellitus and deafness (MIDD). A treatment for MIDD to improve insulin secretory defects and reduce deafness has not been established. The effects of coenzyme Q10 (CoQ10) treatment on insulin secretory response, hearing capacity and clinical symptoms of MIDD were investigated. 28 MIDD patients (CoQ10-DM), 7 mutant subjects with impaired glucose tolerance (IGT), and 15 mutant subjects with normal glucose tolerance (NGT) were treated daily with oral administration of 150 mg of CoQ10 for 3 years. Insulin secretory response, blood lactate after exercise, hearing capacity and other laboratory examinations were investigated every year. In the same way we evaluated 16 MIDD patients (control-DM), 5 mutant IGT and 5 mutant NGT subjects in yearly examinations. The insulin secretory response assessed by glucagon-induced C-peptide secretion and 24 h urinary C-peptide excretion after 3 years in the CoQ10-DM group was significantly higher than that in the control-DM group. CoQ10 therapy prevented progressive hearing loss and improved blood lactate after exercise in the MIDD patients. CoQ10 treatment did not affect the diabetic complications or other clinical symptoms of MIDD patients. CoQ10 treatment did not affect the insulin secretory capacity of the mutant IGT and NGT subjects. There were no side effects during therapy. This is the first report demonstrating the therapeutic usefulness of CoQ10 on MIDD.

Physiological responses of horses to a treadmill simulated speed and endurance test in high heat and humidity before and after humid heat acclimation.

PubMed

Marlin, D J; Scott, C M; Schroter, R C; Harris, R C; Harris, P A; Roberts, C A; Mills, P C

1999-01-01

To investigate whether horses were able to acclimate to conditions of high temperature and humidity, 5 horses of different breeds were trained for 80 min on 15 consecutive days on a treadmill at 30 degrees C and 80%RH. Training consisted of a combination of long duration low-intensity exercise, medium duration medium intensity exercise and short duration high intensity exercise. Between training sessions the horses were maintained at 11+/-3 degrees C and 74+/-2%RH. Before (PRE-ACC) and after acclimation (POST-ACC) the horses undertook a simulated Competition Exercise Test (CET), designed to represent the Speed and Endurance Test of a 3-day event, at 30 degrees C/80%RH. Maximal oxygen uptake (VO2PEAK) was not changed following acclimation (PRE-ACC 141+/-8 ml/min/kg bwt vs. POST-ACC 145+/-9 ml/min/kg bwt [STPD], P>0.05). Following acclimation, 4 of the 5 horses were able to complete a significantly greater amount of Phase D in the CET (PRE-ACC 6.3+/-0.3 min vs. POST-ACC 7.3+/-0.3 min, P<0.05; target time = 8 min). Resting body temperatures (pulmonary artery [TPA], rectal [TREC] and tail-skin [TTSK] temperatures) were all significantly lower following acclimation. During exercise, metabolic heat production (M) and heat dissipation (HD), for the same exercise duration, were both significantly lower following acclimation (P<0.05), although heat storage (HS) was significantly higher (P<0.05). The higher heat storage following acclimation was associated with a lower TTSK for a given TPA and a decreased total fluid loss (% bodyweight, P<0.05). Plasma volume was not changed following acclimation. The relationship of sweating rate (SR) to TPA or TTSK on either the neck or the gluteal region was not significantly altered by acclimation, although the onset of sweating occurred at a lower TPA or TTSK following acclimation (P<0.05). The horses in the present study showed a number of physiological adaptations to a period of 15 days of exposure to high heat and humidity consistent with a humid heat acclimation response. These changes were mostly similar to those reported to occur in man and other species and were consistent with thermal acclimation and an increased thermotolerance, leading to an improved exercise tolerance. It is concluded that a 15 day period of acclimation is beneficial for horses from cooler and or drier climates, that have to compete in hot humid conditions and that this may redress, to some extent, the decrement in exercise tolerance seen in nonacclimated horses and reduce the risk of heat related disorders, such as heat exhaustion.

Creatine Use and Exercise Heat Tolerance in Dehydrated Men

PubMed Central

Watson, Greig; Casa, Douglas J; Fiala, Kelly A; Hile, Amy; Roti, Melissa W; Healey, Julie C; Armstrong, Lawrence E; Maresh, Carl M

2006-01-01

Context: Creatine monohydrate (CrM) use is highly prevalent in team sports (eg, football, lacrosse, ice hockey) and by athletes at the high school, college, professional, and recreational levels. Concerns have been raised about whether creatine use is associated with increased cramping, muscle injury, heat intolerance, and risk of dehydration. Objective: To assess whether 1 week of CrM supplementation would compromise hydration status, alter thermoregulation, or increase the incidence of symptoms of heat illness in dehydrated men performing prolonged exercise in the heat. Design: Double-blind, randomized, crossover design. Setting: Human Performance Laboratory. Patients or Other Participants: Twelve active males, age = 22 ± 1 year, height = 180 ± 3 cm, mass = 78.8 ± 1.2 kg, body fat = 9 ± 1%, V̇o2peak = 50.9 ± 1 ml·kg−1·min−1. Intervention(s): Subjects consumed 21.6 g·d−1 of CrM or placebo for 7 days, underwent 48 ± 10 days of washout between treatments, and then crossed over to the alternate treatment in the creatine group. On day 7 of each treatment, subjects lost 2% body mass by exercising in 33.5°C and then completed an 80-minute exercise heat-tolerance test (33.5°C ± 0.5°C, relative humidity = 41 ± 12%). The test consisted of four 20-minute sequences of 4 minutes of rest, alternating a 3-minute walk and 1-minute high-intensity run 3 times, and walking for 4 minutes. Main Outcome Measures: Thermoregulatory, cardiorespiratory, metabolic, urinary, and perceptual responses. Results: On day 7, body mass had increased 0.88 kg. No interaction or treatment differences for placebo versus CrM during the exercise heat-tolerance test were noted in thermoregulatory (rectal temperature, 39.3 ± 0.4°C versus 39.4 ± 0.4°C) cardiorespiratory (V̇o2, 21.4 ± 2.7 versus 20.0 ± 1.8 ml·kg−1·min−1; heart rate, 192 ± 10 versus 192 ± 11 beats·min−1; mean arterial pressure, 90 ± 9 versus 88 ± 5 mm Hg), metabolic (lactate, 6.7 ± 2.7 versus 7.0 ± 3.0 mmol·L−1), perceptual thirst (thirst, 7 ± 1 versus 7 ± 1; thermal sensation, 8 ± 2 versus 8 ± 1; rating of perceived exertion, 17 ± 3 versus 17 ± 2), plasma glucose (0–20 minutes of exercise heat-tolerance, 6.5 ± 1.2 versus 6.8 ± 0.8 mmol·L−1), plasma (297 ± 5 versus 300 ± 4 mOsm·kg−1) and urine (792 ± 117 versus 651 ± 134 mOsm·kg−1), urine specific gravity (1.025 ± 0.003 versus 1.030 ± 0.005) and urine color (7 ± 1 versus 6 ± 1) measures were increased during CrM. Environmental Symptoms Questionnaire scores were similar between treatments. The levels of dehydration incurred during dehydration and the exercise heat-tolerance test were similar and led to similar cumulative body mass losses (−4.09 ± 0.53 versus −4.38 ± 0.58% body mass). Conclusions: Short-term CrM supplementation did not increase the incidence of symptoms or compromise hydration status or thermoregulation in dehydrated, trained men exercising in the heat. PMID:16619091

Fluid and electrolyte balance in ultra-endurance sport.

PubMed

Rehrer, N J

2001-01-01

It is well known that fluid and electrolyte balance are critical to optimal exercise performance and, moreover, health maintenance. Most research conducted on extreme sporting endeavour (>3 hours) is based on case studies and studies involving small numbers of individuals. Ultra-endurance sportsmen and women typically do not meet their fluid needs during exercise. However, successful athletes exercising over several consecutive days come close to meeting fluid needs. It is important to try to account for all factors influencing bodyweight changes, in addition to fluid loss, and all sources of water input. Increasing ambient temperature and humidity can increase the rate of sweating by up to approximately 1 L/h. Depending on individual variation, exercise type and particularly intensity, sweat rates can vary from extremely low values to more than 3 L/h. Over-hydration, although not frequently observed, can also present problems, as can inappropriate fluid composition. Over-hydrating or meeting fluid needs during very long-lasting exercise in the heat with low or negligible sodium intake can result in reduced performance and, not infrequently, hyponatraemia. Thus, with large rates of fluid ingestion, even measured just to meet fluid needs, sodium intake is vital and an increased beverage concentration [30 to 50 mmol/L (1.7 to 2.9 g NaCl/L) may be beneficial. If insufficient fluids are taken during exercise, sodium is necessary in the recovery period to reduce the urinary output and increase the rate of restoration of fluid balance. Carbohydrate inclusion in a beverage can affect the net rate of water assimilation and is also important to supplement endogenous reserves as a substrate for exercising muscles during ultra-endurance activity. To enhance water absorption, glucose and/or glucose-containing carbohydrates (e.g. sucrose, maltose) at concentrations of 3 to 5% weight/volume are recommended. Carbohydrate concentrations above this may be advantageous in terms of glucose oxidation and maintaining exercise intensity, but will be of no added advantage and, if hyperosmotic, will actually reduce the net rate of water absorption. The rate of fluid loss may exceed the capacity of the gastrointestinal tract to assimilate fluids. Gastric emptying, in particular, may be below the rate of fluid loss, and therefore, individual tolerance may dictate the maximum rate of fluid intake. There is large individual variation in gastric emptying rate and tolerance to larger volumes. Training to drink during exercise is recommended and may enhance tolerance.

An experimental analysis of acquired impulse control among adult humans intolerant to alcohol

PubMed Central

Wang, Jianxin; Rao, Yulei; Houser, Daniel E.

2017-01-01

The ability to control tempting impulses impacts health, education, and general socioeconomic outcomes among people at all ages. Consequently, whether and how impulse control develops in adult populations is a topic of enduring interest. Although past research has shed important light on this question using controlled intervention studies, here we take advantage of a natural experiment in China, where males but not females encounter substantial social pressure to consume alcohol. One-third of our sample, all of whom are Han Chinese, is intolerant to alcohol, whereas the remaining control sample is observationally identical but alcohol tolerant. Consistent with previous literature, we find that intolerant males are significantly more likely to exercise willpower to limit their alcohol consumption than alcohol-tolerant males. In view of the strength model of self-control, we hypothesize that this enables improved impulse control in other contexts as well. To investigate this hypothesis, we compare decisions in laboratory games of self-control between the tolerant and intolerant groups. We find that males intolerant to alcohol and who regularly encounter drinking environments control their selfish impulses significantly better than their tolerant counterparts. On the other hand, we find that female Han Chinese intolerant to alcohol do not use self-control to limit alcohol consumption more than tolerant females, nor do the tolerant and intolerant females exhibit differences in self-control behaviors. Our research indicates that impulse control can be developed in adult populations as a result of self-control behaviors in natural environments, and shows that this skill has generalizable benefits across behavioral domains. PMID:28119501

An experimental analysis of acquired impulse control among adult humans intolerant to alcohol.

PubMed

Wang, Jianxin; Rao, Yulei; Houser, Daniel E

2017-02-07

The ability to control tempting impulses impacts health, education, and general socioeconomic outcomes among people at all ages. Consequently, whether and how impulse control develops in adult populations is a topic of enduring interest. Although past research has shed important light on this question using controlled intervention studies, here we take advantage of a natural experiment in China, where males but not females encounter substantial social pressure to consume alcohol. One-third of our sample, all of whom are Han Chinese, is intolerant to alcohol, whereas the remaining control sample is observationally identical but alcohol tolerant. Consistent with previous literature, we find that intolerant males are significantly more likely to exercise willpower to limit their alcohol consumption than alcohol-tolerant males. In view of the strength model of self-control, we hypothesize that this enables improved impulse control in other contexts as well. To investigate this hypothesis, we compare decisions in laboratory games of self-control between the tolerant and intolerant groups. We find that males intolerant to alcohol and who regularly encounter drinking environments control their selfish impulses significantly better than their tolerant counterparts. On the other hand, we find that female Han Chinese intolerant to alcohol do not use self-control to limit alcohol consumption more than tolerant females, nor do the tolerant and intolerant females exhibit differences in self-control behaviors. Our research indicates that impulse control can be developed in adult populations as a result of self-control behaviors in natural environments, and shows that this skill has generalizable benefits across behavioral domains.

Pre-gravid physical activity and reduced risk of glucose intolerance in pregnancy: the role of insulin sensitivity.

PubMed

Retnakaran, Ravi; Qi, Ying; Sermer, Mathew; Connelly, Philip W; Zinman, Bernard; Hanley, Anthony J G

2009-04-01

Pre-gravid physical activity has been associated with a reduced risk of gestational diabetes mellitus (GDM), although neither the types of exercise nor the physiologic mechanisms underlying this protective effect have been well-studied. Thus, we sought to study the relationships between types of pre-gravid physical activity and metabolic parameters in pregnancy, including glucose tolerance, insulin sensitivity and beta-cell function. A total of 851 women underwent a glucose challenge test (GCT) and a 3-h oral glucose tolerance test (OGTT) in late pregnancy, yielding four glucose tolerance groups: (i) GDM; (ii) gestational impaired glucose tolerance (GIGT); (iii) abnormal GCT with normal glucose tolerance on OGTT (abnormal GCT NGT); and (iv) normal GCT with NGT on OGTT (normal GCT NGT). Pre-gravid physical activity was assessed using the Baecke questionnaire, which measures (i) total physical activity and (ii) its three component domains: work, nonsport leisure-time, and vigorous/sports activity. Glucose tolerance status improved across increasing quartiles of pre-gravid total physical activity (P = 0.0244). Whereas neither work nor nonsport leisure-time activity differed between glucose tolerance groups, pre-gravid vigorous/sports activity was significantly higher in women with normal GCT NGT compared to women with (i) abnormal GCT NGT (P = 0.0018) (ii) GIGT (P = 0.0025), and (iii) GDM (P = 0.0044). In particular, vigorous/sports activity correlated with insulin sensitivity (measured by IS(OGTT)) (r = 0.21, P < 0.0001). Furthermore, on multiple linear regression analysis, pre-gravid vigorous/sports activity emerged as a significant independent predictor of IS(OGTT) in pregnancy (t = 4.97, P < 0.0001). Pre-gravid vigorous/sports activity is associated with a reduced risk of glucose intolerance in pregnancy, an effect likely mediated by enhanced insulin sensitivity.

Application of Acute Maximal Exercise to Enhance Mechanisms Underlying Blood Pressure Regulation and Orthostatic Tolerance After Exposure to Simulated Microgravity

NASA Technical Reports Server (NTRS)

Convertino, V. A.; Engelke, K. A.; Doerr, D. F.

1999-01-01

Development of orthostatic hypotension and intolerance in astronauts who return to earth following a spaceflight mission represents a significant operational concern to NASA. Reduced plasma volume, vascular resistance, and baroreflex responsiveness following exposure to actual and ground-based analogs of microgravity have been associated with orthostatic instability, suggesting that these mechanisms may contribute alone or in combination to compromise of blood pressure regulation after spaceflight. It therefore seems reasonable that development of procedures designed to reverse or restore the effects of microgravity on regulatory mechanisms of blood volume, vascular resistance and cardiac function should provide some protection against postflight orthostatic intolerance. Several investigations have provided evidence that a single bout of exhaustive dynamic exercise enhances functions of mechanisms responsible for blood pressure stability. Therefore, the purpose of our research project was to conduct a series of experiments using ground-based analogs of reduced gravity (i.e., prolonged restriction to the upright standing posture) in human subjects to investigate the hypothesis that a single bout of dynamic maximal exercise would restore blood volume, vascular resistance and cardiac function and improve blood pressure stability.

The effect of endurance training and subsequent physical inactivity on glycaemic control after oral glucose load and physical exercise in healthy men

NASA Astrophysics Data System (ADS)

Radikova, Zofia; Ksinantova, Lucia; Kaciuba-Uscilko, Hanna; Nazar, Krystyna; Vigas, Milan; Koska, Juraj

2007-02-01

Physical inactivity during space flight has a profound effect on glucose metabolism. The aim of this study was to test whether endurance training (ET) may improve a negative effect of subsequent -6∘ head-down bed rest (HDBR) on glucose metabolism. Fourteen healthy males completed the study consisting of 6 weeks lasting ET followed by 6 days HDBR. Treadmill exercise at 80% of pre-training VO2max and 75 g oral glucose tolerance test (OGTT) were performed before and after ET as well as after HDBR. ET increased VO2max by 11%. ET significantly lowered while HDBR had no effect on fasting and OGTT plasma glucose levels. ET had no effect while HDBR was followed by an augmentation of insulin and C-peptide response to OGTT. Insulin sensitivity tended to increase after ET and to decrease during HDBR, however, mostly without statistical significance. Plasma glucose, insulin and C-peptide response to exercise were elevated after HDBR only. Our study shows that antecedent physical training could ameliorate a negative effect of simulated microgravity on insulin-mediated glucose metabolism.

Estrogen or raloxifene during postmenopausal weight loss: adiposity and cardiometabolic outcomes.

PubMed

Van Pelt, R E; Gozansky, W S; Wolfe, P; Kittelson, J M; Jankowski, C M; Schwartz, R S; Kohrt, W M

2014-04-01

Estrogen-based hormone therapy (HT) attenuates abdominal fat gain after menopause, but whether HT improves abdominal fat loss during weight loss is unknown. It was hypothesized that HT or a selective estrogen receptor modulator (raloxifene) would augment reductions in abdominal visceral fat during weight loss when compared to placebo, potentially increasing improvements in glucose tolerance and lipid profile. Healthy postmenopausal women (n = 119; age 50-70 yr) underwent a 6-month weight-loss (primarily exercise) intervention with randomization to raloxifene (60 mg/d), HT (conjugated estrogens, 0.625 mg/d), or placebo. Outcomes were change in total and abdominal (visceral and subcutaneous) fat mass, lipid profile, and fasting and post-challenge glucose and insulin. Neither HT nor raloxifene augmented loss of total or abdominal fat mass during exercise-induced weight loss when compared with placebo. Weight loss-induced improvements in risk factors were similar among the three groups, except for a greater reduction in fasted glucose in the HT group (difference in change [95%CI] from placebo; -0.40 [-0.76, -0.05]) and greater reductions in LDL (-0.36 [-0.63, -0.09]) and increases in HDL (0.15 [0.07, 0.24]) in both treatment groups. Postmenopausal HT and raloxifene did not increase abdominal fat loss during weight loss, but did improve some cardiometabolic outcomes. Copyright © 2013 The Obesity Society.

Influence of muscle mass and work on post-exercise glucose and insulin responses in young untrained subjects.

PubMed

Brambrink, J K; Fluckey, J D; Hickey, M S; Craig, B W

1997-11-01

The 18 h post-exercise glucose and insulin responses of six male and six female subjects were measured following one- or two-leg cycling to determine the influence of muscle mass involvement and work. Each subject performed three exercise trials on a Cybex Met 100 cycle ergometer: (1) two-leg exercise for 30 min at 60% of the two-leg VO2 max; (2) one-leg exercise for 30 min at 60% of one-leg VO2 max; and (3) one-leg exercise (one-leg TW) at 60% of the one-leg VO2 max with the total work performed equal to that of the two-leg trial (duration approximately 50 min). These trials were preceded by 2 days of inactivity and followed by an 18 h post-exercise 75 g oral glucose tolerance test (OGTT). The glucose response during the baseline OGTT demonstrated that the subjects had normal glucose tolerance with fasting serum glucose levels of 5.1 mM, and 1 and 2 h serum glucose less than 7.8 mM, respectively. The 18 h post-exercise glucose responses were significantly lower following the two-leg trial (P < 0.05), with the area under the curve values being 129.9 mM h-1 less than the resting control level. The 18 h post-exercise insulin AUC response of the two-leg trial was significantly lower than either of the one-leg responses (14.7 pM below the one-leg and 5.0 pM below the one-leg TW) but was not associated with a change in C-peptide. The 18 h post-exercise insulin levels of the one-leg and one-leg TW trials were above or near the resting control values, but were not accompanied by a significant change in C-peptide. In conclusion, the data presented here show that the amount of muscle tissue utilized during an exercise bout can influence both the glucose and insulin responses, whereas the amount of total work employed during the exercise had no effect on either of these parameters.

[Exercise dependence--symptoms and mechanisms].

PubMed

Guszkowska, Monika

2012-01-01

The aim of this article is to synthesise the knowledge about the phenomenon of exercise dependence (ED), which is now characterised by an obsessive preoccupation with exercise, negative in nature. ED could be operationalized as a multidimensional maladaptive pattern of exercise, leading to clinically impairment or distress. Its criteria are: tolerance, withdrawal effects, lack of control, reductions in other activities, impaired psychological, social or physical functioning. For primary ED, the physical activity is an end in itself; for secondary ED, motivation is extrinsic--to control or alter body mass and shape. Estimates of the prevalence of ED range from 2-3% to 20-30%. Hypotheses of ED development concentrate on beta-endorphin, sympathetic arousal, affect regulation or some psychological explanations (e.g., exercise as distractor).

Creatine kinase response to high-intensity aerobic exercise in adult-onset muscular dystrophy.

PubMed

Andersen, Søren P; Sveen, Marie-Louise; Hansen, Regitze S; Madsen, Karen L; Hansen, Jonas B; Madsen, Mads; Vissing, John

2013-12-01

We investigated the effect of high-intensity exercise on plasma creatine kinase (CK) in patients with muscular dystrophies. Fourteen patients with Becker (BMD), facioscapulohumeral (FSHD), or limb-girdle type 2 (LGMD2) muscular dystrophy, and 8 healthy subjects performed 5 cycling tests: an incremental max test, and tests at 65%, 75%, 85%, and 95% of maximal oxygen uptake (VO2max ). Heart rate and oxygen consumption were measured during the tests, and plasma CK was measured before, immediately after, and 24 hours after exercise. All subjects were able to perform high-intensity exercise at the different levels. In patients with LGMD2 and FSHD, CK normalized 24 hours after exercise compared with the pre-exercise value, whereas those with BMD and healthy controls had elevated CK values 24 hours after exercise. The findings suggest that high-intensity exercise is generally well tolerated in patients with LGMD2 and FSHD, whereas those with BMD may be more prone to exercise-induced damage. Copyright © 2013 Wiley Periodicals, Inc.

Free Fatty Acid-Induced Hepatic Insulin Resistance is Attenuated Following Lifestyle Intervention in Obese Individuals with Impaired Glucose Tolerance

PubMed Central

Haus, Jacob M.; Solomon, Thomas P. J.; Marchetti, Christine M.; Edmison, John M.; González, Frank; Kirwan, John P.

2010-01-01

Objective: The objective of the study was to examine the effects of an exercise/diet lifestyle intervention on free fatty acid (FFA)-induced hepatic insulin resistance in obese humans. Research Design and Methods: Obese men and women (n = 23) with impaired glucose tolerance were randomly assigned to either exercise training with a eucaloric (EU; ∼1800 kcal; n = 11) or hypocaloric (HYPO; ∼1300 kcal; n = 12) diet for 12 wk. Hepatic glucose production (HGP; milligrams per kilogram fat-free mass−1 per minute−1) and hepatic insulin resistance were determined using a two-stage sequential hyperinsulinemic (40 mU/m2 · min−1) euglycemic (5.0 mm) clamp with [3-3H]glucose. Measures were obtained at basal, during insulin infusion (INS; 120 min), and insulin plus intralipid/heparin infusion (INS/FFA; 300 min). Results: At baseline, basal HGP was similar between groups; hyperinsulinemia alone did not completely suppress HGP, whereas INS/FFA exhibited less suppression than INS (EU, 4.6 ± 0.8, 2.0 ± 0.5, and 2.6 ± 0.4; HYPO, 3.8 ± 0.5, 1.2 ± 0.3, and 2.3 ± 0.4, respectively). After the intervention the HYPO group lost more body weight (P < 0.05) and fat mass (P < 0.05). However, both lifestyle interventions reduced hepatic insulin resistance during basal (P = 0.005) and INS (P = 0.001) conditions, and insulin-mediated suppression of HGP during INS was equally improved in both groups (EU: −42 ± 22%; HYPO: −50 ± 20%, before vs. after, P = 0.02). In contrast, the ability of insulin to overcome FFA-induced hepatic insulin resistance and HGP was improved only in the HYPO group (EU: −15 ± 24% vs. HYPO: −58 ± 19%, P = 0.02). Conclusions: Both lifestyle interventions are effective in reducing hepatic insulin resistance under basal and hyperinsulinemic conditions. However, the reversal of FFA-induced hepatic insulin resistance is best achieved with a combined exercise/caloric-restriction intervention. PMID:19906790

Effects of a Single Bout of Aerobic Exercise Versus Resistance Training on Cognitive Vulnerabilities for Anxiety Disorders.

PubMed

Broman-Fulks, Joshua J; Kelso, Kerry; Zawilinski, Laci

2015-01-01

The purpose of this study was to compare the relative effects of a single bout of aerobic exercise versus resistance training on cognitive vulnerabilities for anxiety disorders. Seventy-seven participants (60% female; 84% Caucasian) were randomized to complete 20 min of moderate-intensity aerobic exercise, resistance training, or rest, followed by a 35% CO2/65% O2 inhalation challenge task. Results indicated that aerobic exercise and resistance training were significantly and equally effective in reducing anxiety sensitivity (AS) compared with rest ((η(2)(p ) = 52), though only aerobic exercise significantly attenuated reactivity to the CO2 challenge task. Neither form of exercise generated observable effects on distress tolerance, discomfort intolerance, or state anxiety (all ps >.10). The results of this study are discussed with regard to their implications for the use of exercise interventions for anxiety and related forms of psychopathology, and potential directions for future research are discussed.

Human Physiological Responses to Cycle Ergometer Leg Exercise During +Gz Acceleration

NASA Technical Reports Server (NTRS)

Chou, J. L.; Stad, N. J.; Barnes, P. R.; Leftheriotis, G. P. N.; Arndt, N. F.; Simonson, S.; Greenleaf, J. E.

1998-01-01

Spaceflight and bed-rest deconditioning decrease maximal oxygen uptake (aerobic power), strength, endurance capacity, and orthostatic tolerance. In addition to extensive use of muscular exercise conditioning as a countermeasure for the reduction in aerobic power (VO(sub 2max)), stimuli from some form of +Gz acceleration conditioning may be necessary to attenuate the orthostatic intolerance component of this deconditioning. Hypothesis: There will be no significant difference in the physiological responses (oxygen uptake, heart rate, ventilation, or respiratory exchange ratio) during supine exercise with moderate +Gz acceleration.

Graded aerobic treadmill testing in pediatric sports-related concussion: safety, clinical use, and patient outcomes.

PubMed

Cordingley, Dean; Girardin, Richard; Reimer, Karen; Ritchie, Lesley; Leiter, Jeff; Russell, Kelly; Ellis, Michael J

2016-12-01

OBJECTIVE The objectives of this study were 2-fold: 1) to evaluate the safety, tolerability, and clinical use of graded aerobic treadmill testing in pediatric patients with sports-related concussion (SRC), and 2) to evaluate the clinical outcomes of treatment with a submaximal aerobic exercise program in patients with physiological post-concussion disorder (PCD). METHODS The authors conducted a retrospective chart review of pediatric patients (age < 20 years) with SRC who were referred to a multidisciplinary pediatric concussion program and underwent graded aerobic treadmill testing between October 9, 2014, and February 11, 2016. Clinical assessments were carried out by a single neurosurgeon and included clinical history taking, physical examination, and recording specific patient-reported concussion-related symptoms using the Post-Concussion Symptom Scale (PCSS). Graded aerobic treadmill testing using a modified Balke protocol for incremental increases in intensity was used as a diagnostic tool to assess physiological recovery, classify post-concussion syndrome (PCS) subtype, and reassess patients following treatment. Patients with a symptom-limited threshold on treadmill testing (physiological PCD) were treated with an individually tailored submaximal exercise prescription and multidisciplinary targeted therapies. RESULTS One hundred six patients (mean age 15.1 years, range 11-19 years) with SRC underwent a total of 141 treadmill tests. There were no serious complications related to treadmill testing in this study. Overall, 138 (97.9%) of 141 tests were well tolerated and contributed valuable clinical information. Treadmill testing confirmed physiological recovery in 63 (96.9%) of 65 patients tested, allowing successful return to play in 61 (93.8%). Treadmill testing was used to diagnose physiological PCD in 58 patients and cervicogenic PCD in 1 patient. Of the 41 patients with physiological PCD who had complete follow-up and were treated with tailored submaximal exercise prescription, 37 (90.2%) were classified as clinically improved and 33 (80.5%) successfully returned to sporting activities. Patients who did not respond or experienced an incomplete response to submaximal aerobic exercise treatment included 7 patients with migraine headaches and 1 patient with a postinjury psychiatric disorder. CONCLUSIONS Graded aerobic treadmill testing is a safe, tolerable, and clinically valuable tool that can assist in the evaluation and management of pediatric SRC. Future research is needed to confirm the clinical value of this tool in return-to-play decision making. Studies are also needed to understand the pathophysiology of physiological PCD and the effects of targeted treatment.

A SIX-WEEK SUPERVISED EXERCISE AND EDUCATIONAL INTERVENTION AFTER TOTAL HIP ARTHROPLASTY: A CASE SERIES

PubMed Central

Madara, Kathleen; Zeni, Joseph A

2017-01-01

Background and Purpose Most rehabilitation interventions after total hip arthroplasty (THA) are not designed to return patients to high-levels of physical activity and, thus, low levels of physical activity and residual weakness are common. The purpose of this case series was to describe the feasibility and preliminary efficacy of an exercise and education intervention for patients after THA who have already completed formal outpatient physical therapy. Study Design Case series Case Description Two participants underwent unilateral THA seven (case A) or eight (case B) months prior to the intervention. Individuals participated in 18 treatment sessions that included progressive aerobic and strengthening exercises and meetings with a health coach. Change in function, strength, and self-reported physical activity were measured. Outcomes 12 months after surgery were compared to a historical cohort of patients after THA. Outcome There were no adverse events during the intervention. At the end of the intervention, hip and knee strength on the surgical side increased approximately 30% compared to baseline in both cases. Activity level, and recreational performance, including walking up stairs and hiking uphill (case A), and running and golfing (case B), improved by the end of the intervention. Most changes were maintained at follow-up, although hip strength for case B decreased 27% after discharge from the intervention. Outcomes for both cases exceeded historical averages for patients 12 months after THA, with the exception of strength in case B. Discussion The exercise intervention was well tolerated and without negative effects in two participants. Both participants increased their ability to complete demanding recreational and sports-related activities, physical activity, and demonstrated improved hip abductor and knee extensor strength. Further research is needed to evaluate the implementation and effectiveness of similar interventions after THA. Level of Evidence Level 4 PMID:28515981

Declining Skeletal Muscle Function in Diabetic Peripheral Neuropathy.

PubMed

Parasoglou, Prodromos; Rao, Smita; Slade, Jill M

2017-06-01

The present review highlights current concepts regarding the effects of diabetic peripheral neuropathy (DPN) in skeletal muscle. It discusses the lack of effective pharmacologic treatments and the role of physical exercise intervention in limb protection and symptom reversal. It also highlights the importance of magnetic resonance imaging (MRI) techniques in providing a mechanistic understanding of the disease and helping develop targeted treatments. This review provides a comprehensive reporting on the effects of DPN in the skeletal muscle of patients with diabetes. It also provides an update on the most recent trials of exercise intervention targeting DPN pathology. Lastly, we report on emerging MRI techniques that have shown promise in providing a mechanistic understanding of DPN and can help improve the design and implementation of clinical trials in the future. Impairments in lower limb muscles reduce functional capacity and contribute to altered gait, increased fall risk, and impaired balance in patients with DPN. This finding is an important concern for patients with DPN because their falls are likely to be injurious and lead to bone fractures, poorly healing wounds, and chronic infections that may require amputation. Preliminary studies have shown that moderate-intensity exercise programs are well tolerated by patients with DPN. They can improve their cardiorespiratory function and partially reverse some of the symptoms of DPN. MRI has the potential to bring new mechanistic insights into the effects of DPN as well as to objectively measure small changes in DPN pathology as a result of intervention. Noninvasive exercise intervention is particularly valuable in DPN because of its safety, low cost, and potential to augment pharmacologic interventions. As we gain a better mechanistic understanding of the disease, more targeted and effective interventions can be designed. Copyright © 2017 Elsevier HS Journals, Inc. All rights reserved.

Evaluation of positive G sub Z tolerance following simulated weightlessness (bedrest)

NASA Technical Reports Server (NTRS)

Jacobson, L. B.; Hyatt, K. H.; Sullivan, R. W.; Cantor, S. A.; Sandler, H.; Rositano, S. A.; Mancini, R. E.

1973-01-01

The magnitude of physiologic changes which are known to occur in human subjects exposed to varying levels of + G sub Z acceleration following bed rest simulation of weightlessness was studied. Bed rest effects were documented by fluid and electrolyte balance studies, maximal exercise capability, 70 deg passive tilt and lower body negative pressure tests and the ability to endure randomly prescribed acceleration profiles of +2G sub Z, +3G sub Z, and +4G sub Z. Six healthy male volunteers were studied during two weeks of bed rest after adequate control observations, followed by two weeks of recovery, followed by a second two-week period of bed rest at which time an Air Force cutaway anti-G suit was used to determine its effectiveness as a countermeasure for observed cardiovascular changes during acceleration. Results showed uniform and significant changes in all measured parameters as a consequence of bed rest including a reduced ability to tolerate +G sub Z acceleration. The use of anti-G suits significantly improved subject tolerance to all G exposures and returned measured parameters such as heart rate and blood pressure towards or to pre-bed-rest (control) values in four of the six cases.

Exercise and Regulation of Bone and Collagen Tissue Biology.

PubMed

Kjaer, Michael; Jørgensen, Niklas Rye; Heinemeier, Katja; Magnusson, S Peter

2015-01-01

The musculoskeletal system and its connective tissue include the intramuscular connective tissue, the myotendinous junction, the tendon, the joints with their cartilage and ligaments, and the bone; they all together play a crucial role in maintaining the architecture of the skeletal muscle, ensuring force transmission, storing energy, protecting joint surface and stability, and ensuring the transfer of muscular forces into resulting limb movement. The musculoskeletal connective tissue structure is relatively stable, but mechanical loading and subsequent mechanotransduction and molecular anabolic signaling can result in some adaptation of the connective tissue, its size, its strength, and its mechanical properties, whereby it can improve its capacity by 5-20% with regular physical activity. For several of the mechanically loaded connective tissues, only limited information regarding molecular and cellular signaling pathways and their adaptation to exercise is available. In contrast to tissue responses with exercise, lack of mechanical tissue loading through inactivity or immobilization of the human body will result in a dramatic loss of connective tissue content, structure, and tolerable load within weeks, to a degree (30-40%) that mimics that of contractile skeletal musculature. This illustrates the importance of regular mechanical load in order to preserve the stabilizing role of the connective tissue for the overall function of the musculoskeletal system in both daily activity and exercise. © 2015 Elsevier Inc. All rights reserved.