The effects of strength training on cognitive performance in elderly women.

PubMed

Smolarek, André de Camargo; Ferreira, Luis Henrique Boiko; Mascarenhas, Luis Paulo Gomes; McAnulty, Steven R; Varela, Karla Daniele; Dangui, Mônica C; de Barros, Marcelo Paes; Utter, Alan C; Souza-Junior, Tácito P

2016-01-01

Aging is a degenerative process marked by recognized functional, physiological, and metabolic impairments, such as dynapenia and diminished cognitive capacity. Therefore, the search for innovative strategies to prevent/delay these physiological and cognitive disorders is essential to guarantee the independence and life quality of an elderly population. The aim of this work is to verify the effect of a 12-week resistance exercise program on the general physical aptitude and cognitive capacities of elderly and sedentary women. Twenty-nine women (65.87±5.69 years) were divided into two groups. The control group was composed of eight elderly women who met the same inclusion criteria of the study and the strength training group was composed of 29 elderly women who were subjected to a resistance exercise program defined by 12 upper and lower limb exercises combined in 3×10 repetitions with 1-minute interval between repetitions and two resting minutes between exercises (three times/week). Weight loads were fixed between 60% and 75% of the apparent 1 repetition maximum, which was estimated by the test of 10 maximum repetitions. The direct curl was performed for upper body strength evaluation with 2.3 kg dumbbells for 30 seconds, whereas the chair test was used for lower body evaluation (total sit-stand movements in 30 seconds). The cognitive capacities of subjects were evaluated by "The Montreal Cognitive Assessment" questionnaire. After 12 weeks, the elderly group showed significant increases in the average upper body strength (58%), lower body strength (68%), and cognitive capacity (19%). The present study demonstrated that regular resistance exercises could provide significant gains on the upper and lower body strength concomitant to positive improvements on cognitive capacities of elderly women, bringing enhanced life quality.

p53 improves aerobic exercise capacity and augments skeletal muscle mitochondrial DNA content.

PubMed

Park, Joon-Young; Wang, Ping-Yuan; Matsumoto, Takumi; Sung, Ho Joong; Ma, Wenzhe; Choi, Jeong W; Anderson, Stasia A; Leary, Scot C; Balaban, Robert S; Kang, Ju-Gyeong; Hwang, Paul M

2009-09-25

Exercise capacity is a physiological characteristic associated with protection from both cardiovascular and all-cause mortality. p53 regulates mitochondrial function and its deletion markedly diminishes exercise capacity, but the underlying genetic mechanism orchestrating this is unclear. Understanding the biology of how p53 improves exercise capacity may provide useful insights for improving both cardiovascular as well as general health. The purpose of this study was to understand the genetic mechanism by which p53 regulates aerobic exercise capacity. Using a variety of physiological, metabolic, and molecular techniques, we further characterized maximum exercise capacity and the effects of training, measured various nonmitochondrial and mitochondrial determinants of exercise capacity, and examined putative regulators of mitochondrial biogenesis. As p53 did not affect baseline cardiac function or inotropic reserve, we focused on the involvement of skeletal muscle and now report a wider role for p53 in modulating skeletal muscle mitochondrial function. p53 interacts with Mitochondrial Transcription Factor A (TFAM), a nuclear-encoded gene important for mitochondrial DNA (mtDNA) transcription and maintenance, and regulates mtDNA content. The increased mtDNA in p53(+/+) compared to p53(-/-) mice was more marked in aerobic versus glycolytic skeletal muscle groups with no significant changes in cardiac tissue. These in vivo observations were further supported by in vitro studies showing overexpression of p53 in mouse myoblasts increases both TFAM and mtDNA levels whereas depletion of TFAM by shRNA decreases mtDNA content. Our current findings indicate that p53 promotes aerobic metabolism and exercise capacity by using different mitochondrial genes and mechanisms in a tissue-specific manner.

Prognostic capacity of a clinically indicated exercise test for cardiovascular mortality is enhanced by combined analysis of exercise capacity, heart rate recovery and T-wave alternans.

PubMed

Minkkinen, Mikko; Nieminen, Tuomo; Verrier, Richard L; Leino, Johanna; Lehtimäki, Terho; Viik, Jari; Lehtinen, Rami; Nikus, Kjell; Kööbi, Tiit; Turjanmaa, Väinö; Kähönen, Mika

2015-09-01

Exercise capacity, heart rate recovery and T-wave alternans are independent predictors of cardiovascular mortality. We tested whether these parameters contain supplementary prognostic information. A total of 3609 consecutive patients (2157 men) referred for a routine, clinically indicated bicycle exercise test were enrolled in the Finnish Cardiovascular Study (FINCAVAS). Exercise capacity was measured in metabolic equivalents, heart rate recovery as the decrease in heart rate from maximum to one minute post-exercise, and T-wave alternans by time-domain Modified Moving Average method. During 57-month median follow-up (interquartile range 35-78 months), 96 patients died of cardiovascular causes (primary endpoint) and 233 from any cause. All three parameters were independent predictors of cardiovascular mortality when analysed as continuous variables. Adding metabolic equivalents (p < 0.001), heart rate recovery (p = 0.002) or T-wave alternans (p = 0.01) to the linear model improved its predictive power for cardiovascular mortality. The combination of low exercise capacity (<6 metabolic equivalents), reduced heart rate recovery (≤12 beats/min) and elevated T-wave alternans (≥60 μV) yielded the highest hazard ratio for cardiovascular mortality of 16.5 (95% confidence interval 4.0-67.7, p < 0.001). Harrell's C index was 0.719 (confidence interval 0.665-0.772) for cardiovascular mortality with previously defined cutpoints (<8 units for metabolic equivalents, ≤18 beats/min for heart rate recovery and ≥60 μV for T-wave alternans). The prognostic capacity of the clinical exercise test is enhanced by combined analysis of exercise capacity, heart rate recovery and T-wave alternans. © The European Society of Cardiology 2014.

Exercise therapy improves aerobic capacity of inpatients with major depressive disorder.

PubMed

Kerling, Arno; von Bohlen, Anne; Kück, Momme; Tegtbur, Uwe; Grams, Lena; Haufe, Sven; Gützlaff, Elke; Kahl, Kai G

2016-06-01

Unipolar depression is one of the most common diseases worldwide and is associated with a higher cardiovascular risk partly due to reduced aerobic capacity. Therefore, the aim of our study was to examine whether a structured aerobic training program can improve aerobic capacity in inpatients with MDD (major depressive disorder). Overall, 25 patients (13 women, 12 men) diagnosed with MDD were included in the study. Parameters of aerobic capacity, such as maximum performance, maximum oxygen consumption, and VAT (ventilatory anaerobic threshold), were assessed on a bicycle ergometer before and 6 weeks after a training period (three times per week for 45 min on two endurance machines). In addition, a constant load test was carried out at 50% of the maximum performance prior to and after the training period. The performance data were compared with 25 healthy controls matched for sex, age, and body mass index before and after the training period. Compared to controls, patients with MDD had significantly lower aerobic capacity. After training, there was a significant improvement in their performance data. A significant difference remained only for VAT between patients with MDD and healthy controls. With regard to the coincidence of MDD with cardiovascular and cardiometabolic disorders, a structured supervised exercise program carried out during hospitalization is a useful supplement for patients with MDD.

Cigarette smoking decreases dynamic inspiratory capacity during maximal exercise in patients with type 2 diabetes.

PubMed

Kitahara, Yoshihiro; Hattori, Noboru; Yokoyama, Akihito; Yamane, Kiminori; Sekikawa, Kiyokazu; Inamizu, Tsutomu; Kohno, Nobuoki

2012-06-01

To investigate the influence of cigarette smoking on exercise capacity, respiratory responses and dynamic changes in lung volume during exercise in patients with type 2 diabetes. Forty-one men with type, 2 diabetes without cardiopulmonary disease were recruited and divided into 28 non-current smokers and 13 current smokers. All subjects received lung function tests and cardiopulmonary exercise testing using tracings of the flow-volume loop. Exercise capacity was compared using the percentage of predicted oxygen uptake at maximal workload (%VO2max). Respiratory variables and inspiratory capacity (IC) were compared between the two groups at rest and at 20%, 40%, 60%, 80% and 100% of maximum workload. Although there was no significant difference in lung function tests between the two groups, venous carboxyhemoglobin (CO-Hb) levels were significantly higher in current smokers. %VO2max was inversely correlated with CO-Hb levels. Changing patterns in respiratory rate, respiratory equivalent and IC were significantly different between the two groups. Current smokers had rapid breathing, a greater respiratory equivalent and a limited increase in IC during exercise. Cigarette smoking diminishes the increase in dynamic IC in patients with type 2 diabetes. As this effect of smoking on dynamic changes in lung volume will exacerbate dynamic hyperinflation in cases complicated by chronic obstructive pulmonary disease, physicians should consider smoking habits and lung function when evaluating exercise capacity in patients with type 2 diabetes.

Quantitative chest computed tomography as a means of predicting exercise performance in severe emphysema.

PubMed

Crausman, R S; Ferguson, G; Irvin, C G; Make, B; Newell, J D

1995-06-01

We assessed the value of quantitative high-resolution computed tomography (CT) as a diagnostic and prognostic tool in smoking-related emphysema. We performed an inception cohort study of 14 patients referred with emphysema. The diagnosis of emphysema was based on a compatible history, physical examination, chest radiograph, CT scan of the lung, and pulmonary physiologic evaluation. As a group, those who underwent exercise testing were hyperinflated (percentage predicted total lung capacity +/- standard error of the mean = 133 +/- 9%), and there was evidence of air trapping (percentage predicted respiratory volume = 318 +/- 31%) and airflow limitation (forced expiratory volume in 1 sec [FEV1] = 40 +/- 7%). The exercise performance of the group was severely limited (maximum achievable workload = 43 +/- 6%) and was characterized by prominent ventilatory, gas exchange, and pulmonary vascular abnormalities. The quantitative CT index was markedly elevated in all patients (76 +/- 9; n = 14; normal < 4). There were correlations between this quantitative CT index and measures of airflow limitation (FEV1 r2 = .34, p = 09; FEV1/forced vital capacity r2 = .46, p = .04) and between maximum workload achieved (r2 = .93, p = .0001) and maximum oxygen utilization (r2 = .83, p = .0007). Quantitative chest CT assessment of disease severity is correlated with the degree of airflow limitation and exercise impairment in pulmonary emphysema.

Determinants of expiratory flow limitation in healthy women during exercise.

PubMed

Dominelli, Paolo B; Guenette, Jordan A; Wilkie, Sabrina S; Foster, Glen E; Sheel, A William

2011-09-01

Expiratory flow limitation (EFL) can occur in healthy young women during exercise. We questioned whether the occurrence and severity of EFL were related to aerobic fitness or anatomical factors. Twenty-two healthy young (<40 yr) women performed a progressive cycle test to exhaustion. The subjects' maximum expiratory flow-volume curve was compiled from several effort-graded vital capacity maneuvers before and after exercise. The maximum expiratory flow-volume curve, along with inspiratory capacity maneuvers, was used to determine lung volumes and expiratory flows and to quantify EFL. To determine relative airway size, we used a ratio sensitive to both airway size and lung volume, called the dysanapsis ratio. The subjects were partitioned into two groups based upon the appearance of >5% EFL. Ten subjects showed EFL during exercise. Forced vital capacities (4.4 ± 0.4 vs 3.7 ± 0.4 L, P < 0.001) and forced expiratory flows for any given lung volume were significantly larger in the non-expiratory flow-limited (NEFL) group. The NEFL group's dysanapsis ratio was significantly larger than that of the EFL group (0.27 ± 0.06 vs 0.21 ± 0.04, respectively, P < 0.05), indicating larger airways in the NEFL group. There was no difference between the NEFL and EFL groups with respect to maximal aerobic capacity (50.8 ± 10.0 vs 46.7 ± 5.9 mL·kg(-1)·min(-1), respectively, P = 0.264). At peak exercise, the NEFL group had a significantly higher end-expiratory lung volume than the EFL group (40.1% ± 4.8% vs 33.7% ± 5.7% FVC, respectively, P < 0.05). We conclude that EFL in women can largely be explained by anatomical factors that influence the capacity to generate flow and volume during exercise rather than fitness per se.

Energy metabolism of the untrained muscle of elite runners as observed by 31P magnetic resonance spectroscopy: evidence suggesting a genetic endowment for endurance exercise.

PubMed Central

Park, J H; Brown, R L; Park, C R; Cohn, M; Chance, B

1988-01-01

The purpose of this study was to investigate whether genetically determined properties of muscle metabolism contribute to the exceptional physical endurance of world-class distance runners. ATP, phosphocreatine, inorganic phosphate, and pH were quantitatively determined by 31P nuclear magnetic resonance spectroscopy in the wrist flexor muscles of elite long-distance runners and sedentary control subjects. These muscles had not been exposed to any specific program of exercise training in either group of subjects. The "untrained" muscles were examined at rest, during two cycles of three grades of exercise, and in recovery. The flexor muscles of the athletes had higher concentrations of phosphocreatine and ATP than did those of the control subjects at rest and during exercise. The athletes' muscles possessed a higher capacity for generation of ATP by oxidative metabolism than did control subjects' muscles according to the following criteria: (i) high force output, 60% of maximum voluntary contraction, was more easily reached and better maintained in both exercise cycles; (ii) the ratio of inorganic phosphate to phosphocreatine rose less during exercise and recovered faster in the postexercise period; (iii) there was no loss of adenine nucleotides or total phosphate from the athletes' muscles but significant losses from the control subjects' muscles; and (iv) the pH decreased no more than 0.1 unit in the athletes' muscles during exercise, attesting to a relatively slow glycolysis and/or a rapid oxidation of lactate. In the muscles of the control subjects, on the other hand, the pH decreased nearly 0.4 unit early in the first exercise cycle, indicating a relatively fast glycolysis and/or slower oxidation of lactate. In the second exercise cycle, the pH returned to near normal in the control subjects' muscles, reflecting diminished lactate formation because of glycogen depletion and lactate washout by the high blood flow induced by exercise. By the end of the exercise program, the maximum voluntary contractile force for the control subjects had declined to less than 60% of the initial value. This decline could be explained best by exhaustion of the glycolytic contribution to muscle contraction. Therefore, the residual maximum strength provided a measure of the oxidative capacity to support contraction, as is discussed. In conclusion, we suggest that a greater oxidative capacity relative to glycolytic capacity for support of contraction in untrained muscle of world-class runners reflects a genetic endowment for physical endurance. Additional systemic effects of training cannot be completely excluded. 31P magnetic resonance spectroscopy provides a noninvasive method for assessing this endowment. PMID:3194388

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 Surgical Curve Correction on Exercise Tolerance and Physical Capacities in Patients of Severe Spinal Deformity.

PubMed

Patil, Prateek C; Rathod, Ashok K; Borde, Mandar; Singh, Vishwajeet; Singh, Hemant U

2016-12-01

Traditionally, surgical intervention for patients with a spinal deformity has been considered for cosmetic benefits, but surgical intervention can alter the lung physiology or volumes and in turn leads to increase in physical capacity and exercise tolerance. Therefore, we conducted this to determine whether a surgical correction would restore the lung physiology, physical capacity and exercise tolerance in patients with kyphoscoliosis. To evaluate the usage of six-minute walk test scores and modified Borg scores as tools/measures for exercise tolerance in patients with spinal deformity and to study the effects of surgical correction of spinal deformity on exercise tolerance with above parameters as the measures. Thirty patients with spinal deformity, who had undergone surgery for deformity correction, were evaluated. All patients were investigated pre-operatively with x-rays of the spine (anteroposterior and lateral views). Clinical tests like breath holding time (after full inspiration) in number of seconds, modified Borg scores, six-minute walk test scores (heart rate, respiratory rate, maximum distance walked); were recorded as measures of exercise tolerance. The patients were followed up on the first, third, sixth and twelfth month post-operatively and tested clinically for breath holding time, modified Borg scores, six-minute walk test scores (heart rate, respiratory rate, maximum distance walked) and x-rays of the spine (anteroposterior and lateral views). In our study, breath holding time (p-value = 0.001) and modified Borg scores (p-value = 0.012) showed a significant improvement at 12 months post-operatively. We noted similar findings with heart rate, respiratory rate and maximum distance walked after a six-minute walk test. Improvements were noted in all the parameters, especially in the group of patients with greater than 60 degrees of cobb angle. However, the differences between the two groups (pre-operative cobb angle less than 60 degrees and pre-operative cobb angle more than 60 degrees) were not significant. The results were analysed and tested for significance using Student's t-test (paired and unpaired as appropriate) and Wilcoxon signed rank test. Surgical correction in cases of spinal deformity improves the cosmetic appearance and balance in the patients. Favourable results of surgical intervention were found in exercise tolerance with improvements in modified Borg scores, six-minute walk test results and breath holding time. The above parameters appear to be good tools for the assessment of physical capacity and exercise tolerance in patients with spinal deformity.

Case Study: Physical Capacity and Nutritional Status Before and After a Single-Handed Yacht Race.

PubMed

Ghiani, Giovanna; Magnani, Sara; Doneddu, Azzurra; Sainas, Gianmarco; Pinna, Virginia; Caboi, Marco; Palazzolo, Girolamo; Tocco, Filippo; Crisafulli, Antonio

2018-06-12

During solitary sailing, the sailor is exposed to sleep deprivation and difficulties in consuming regular meals. Sailor weight loss is often reported. In the present case study, we describe changes in the physical capacity and nutritional status of an athlete attempting a single-handed yacht race around the globe. An Italian male ocean racer (Gaetano Mura) asked for our help to reach an optimum level of physical and nutritional preparation. We planned his diet after assessing his anthropometric parameters and body composition, as well as his usual energy intake and nutritional expenditure. The diet consisted of 120 meals stored in sealed plastic bags. Before his departure, GM performed two incremental exercise tests (cycle ergometry and arm crank ergometry) to assess his physical capacity. Cardiac functions were also estimated by Doppler echocardiography. All measures and exercise tests were repeated 10 days after GM finished the race, which lasted 64 days. Anthropometric measures did not change significantly, with the exception of arm fat area and thigh muscle area, which decreased. There were evident increments in maximum oxygen intake and maximum workload during arm cranking after the race. On the contrary, maximum oxygen uptake and maximum workload decreased during cycling. Finally, end-diastolic and stroke volume decreased after the race. It was concluded that nutritional counseling was useful to avoid excessive changes in nutritional status and body composition due to 64 days of solitary navigation. However, a reduction in physical leg capacity and cardiovascular functions secondary to leg disuse were present.

Exercise as a remedy for sarcopenia.

PubMed

Landi, Francesco; Marzetti, Emanuele; Martone, Anna M; Bernabei, Roberto; Onder, Graziano

2014-01-01

Although prolongation of life is a significant public health aim, at the same time the extended life should involve preservation of the capacity to live independently. Consequently, the identification of cost-effectiveness interventions to prevent frailty is one of the most important public health challenges. In the present review, we present the available evidence regarding the impact of physical exercise on the components of frailty syndrome and, in particular, as a remedy for sarcopenia. Resistance exercise training is more effective in increasing muscle mass and strength, whereas endurance exercises training is superior for maintaining and improving maximum aerobic power. Based on these evidences, recommendations for adult and frail older people should include a balanced program of both endurance and strength exercises, performed on a regular schedule (at least 3 days a week). Regular exercise is the only strategy found to consistently prevent frailty and improve sarcopenia and physical function in older adults. Physical exercises increase aerobic capacity, muscle strength and endurance, by ameliorating aerobic conditioning and/or strength. In older patients, exercise and physical activity produce at least the same beneficial effects observed in younger individuals.

Cross-training in birds: cold and exercise training produce similar changes in maximal metabolic output, muscle masses and myostatin expression in house sparrows (Passer domesticus)

PubMed Central

Zhang, Yufeng; Eyster, Kathleen; Liu, Jin-Song; Swanson, David L.

2015-01-01

ABSTRACT Maximal metabolic outputs for exercise and thermogenesis in birds presumably influence fitness through effects on flight and shivering performance. Because both summit (Msum, maximum thermoregulatory metabolic rate) and maximum (MMR, maximum exercise metabolic rate) metabolic rates are functions of skeletal muscle activity, correlations between these measurements and their mechanistic underpinnings might occur. To examine whether such correlations occur, we measured the effects of experimental cold and exercise training protocols for 3 weeks on body (Mb) and muscle (Mpec) masses, basal metabolic rate (BMR), Msum, MMR, pectoralis mRNA and protein expression for myostatin, and mRNA expression of TLL-1 and TLL-2 (metalloproteinase activators of myostatin) in house sparrows (Passer domesticus). Both training protocols increased Msum, MMR, Mb and Mpec, but BMR increased with cold training and decreased with exercise training. No significant differences occurred for pectoralis myostatin mRNA expression, but cold and exercise increased the expression of TLL-1 and TLL-2. Pectoralis myostatin protein levels were generally reduced for both training groups. These data clearly demonstrate cross-training effects of cold and exercise in birds, and are consistent with a role for myostatin in increasing pectoralis muscle mass and driving organismal increases in metabolic capacities. PMID:25987736

Effect of exercise test on pulmonary function of obese adolescents.

PubMed

Faria, Alethéa Guimarães; Ribeiro, Maria Angela G O; Marson, Fernando Augusto Lima; Schivinski, Camila Isabel S; Severino, Silvana Dalge; Ribeiro, José Dirceu; Barros Filho, Antônio A

2014-01-01

to investigate the pulmonary response to exercise of non-morbidly obese adolescents, considering the gender. a prospective cross-sectional study was conducted with 92 adolescents (47 obese and 45 eutrophic), divided in four groups according to obesity and gender. Anthropometric parameters, pulmonary function (spirometry and oxygen saturation [SatO2]), heart rate (HR), blood pressure (BP), respiratory rate (RR), and respiratory muscle strength were measured. Pulmonary function parameters were measured before, during, and after the exercise test. BP and HR were higher in obese individuals during the exercise test (p = 0.0001). SatO2 values decreased during exercise in obese adolescents (p = 0.0001). Obese males had higher levels of maximum inspiratory and expiratory pressures (p = 0.0002) when compared to obese and eutrophic females. Obese males showed lower values of maximum voluntary ventilation, forced vital capacity, and forced expiratory volume in the first second when compared to eutrophic males, before and after exercise (p = 0.0005). Obese females had greater inspiratory capacity compared to eutrophic females (p = 0.0001). Expiratory reserve volume was lower in obese subjects when compared to controls (p ≤ 0,05). obese adolescents presented changes in pulmonary function at rest and these changes remained present during exercise. The spirometric and cardiorespiratory values were different in the four study groups. The present data demonstrated that, in spite of differences in lung growth, the model of fat distribution alters pulmonary function differently in obese female and male adolescents. Copyright © 2013 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

Effects of different strength training frequencies on maximum strength, body composition and functional capacity in healthy older individuals.

PubMed

Turpela, Mari; Häkkinen, Keijo; Haff, Guy Gregory; Walker, Simon

2017-11-01

There is controversy in the literature regarding the dose-response relationship of strength training in healthy older participants. The present study determined training frequency effects on maximum strength, muscle mass and functional capacity over 6months following an initial 3-month preparatory strength training period. One-hundred and six 64-75year old volunteers were randomly assigned to one of four groups; performing strength training one (EX1), two (EX2), or three (EX3) times per week and a non-training control (CON) group. Whole-body strength training was performed using 2-5 sets and 4-12 repetitions per exercise and 7-9 exercises per session. Before and after the intervention, maximum dynamic leg press (1-RM) and isometric knee extensor and plantarflexor strength, body composition and quadriceps cross-sectional area, as well as functional capacity (maximum 7.5m forward and backward walking speed, timed-up-and-go test, loaded 10-stair climb test) were measured. All experimental groups increased leg press 1-RM more than CON (EX1: 3±8%, EX2: 6±6%, EX3: 10±8%, CON: -3±6%, P<0.05) and EX3 improved more than EX1 (P=0.007) at month 9. Compared to CON, EX3 improved in backward walk (P=0.047) and EX1 in timed-up-and-go (P=0.029) tests. No significant changes occurred in body composition. The present study found no evidence that higher training frequency would induce greater benefit to maximum walking speed (i.e. functional capacity) despite a clear dose-response in dynamic 1-RM strength, at least when predominantly using machine weight-training. It appears that beneficial functional capacity improvements can be achieved through low frequency training (i.e. 1-2 times per week) in previously untrained healthy older participants. Copyright © 2017 Elsevier Inc. All rights reserved.

High Mid-Flow to Vital Capacity Ratio and the Response to Exercise in Children With Congenital Heart Disease.

PubMed

Vilozni, Daphna; Alcaneses-Ofek, Maria Rosario; Reuveny, Ronen; Rosenblum, Omer; Inbar, Omri; Katz, Uriel; Ziv-Baran, Tomer; Dubnov-Raz, Gal

2016-12-01

Pulmonary mechanics may play a role in exercise intolerance in patients with congenital heart disease (CHD). A reduced FVC volume could increase the ratio between mid-flow (FEF 25-75% ) and FVC, which is termed high dysanapsis. The relationship between high dysanapsis and the response to maximum-intensity exercise in children with CHD had not yet been studied. The aim of this work was to examine whether high dysanapsis is related to the cardiopulmonary response to maximum-intensity exercise in pediatric subjects with CHD. We retrospectively collected data from 42 children and adolescents with CHD who had either high dysanapsis (ratio >1.2; n = 21) or normal dysanapsis (control) (n = 21) as measured by spirometry. Data extracted from cardiopulmonary exercise test reports included peak values of heart rate, work load, V̇ O 2 , V̇ CO 2 , and ventilation parameters and submaximum values, including ventilatory threshold and ventilatory equivalents. There were no significant differences in demographic and clinical parameters between the groups. Participants with high dysanapsis differed from controls in lower median peak oxygen consumption (65.8% vs 83.0% of predicted, P = .02), peak oxygen pulse (78.6% vs 87.8% of predicted, P = .02), ventilatory threshold (73.8% vs 85.3% of predicted, P = .03), and maximum breathing frequency (106% vs 121% of predicted, P = .035). In the high dysanapsis group only, median peak ventilation and tidal volume were significantly lower than 80% of predicted values. In children and adolescents with corrected CHD, high dysanapsis was associated with a lower ventilatory capacity and reduced aerobic fitness, which may indicate respiratory muscle impairments. Copyright © 2016 by Daedalus Enterprises.

Pulmonary vascular function and exercise capacity in black sub-Saharan Africans.

PubMed

Simaga, Bamodi; Vicenzi, Marco; Faoro, Vitalie; Caravita, Sergio; Di Marco, Giovanni; Forton, Kevin; Deboeck, Gael; Lalande, Sophie; Naeije, Robert

2015-09-01

Sex and age affect the pulmonary circulation. Whether there may be racial differences in pulmonary vascular function is unknown. Thirty white European Caucasian subjects (15 women) and age and body-size matched 30 black sub-Saharan African subjects (15 women) underwent a cardiopulmonary exercise test and exercise stress echocardiography with measurements of pulmonary artery pressure (PAP) and cardiac output (CO). A pulmonary vascular distensibility coefficient α was mathematically determined from the natural curvilinearity of multipoint mean PAP (mPAP)-CO plots. Maximum oxygen uptake (V̇o2max) and workload were higher in the whites, while maximum respiratory exchange ratio and ventilatory equivalents for CO2 were the same. Pulmonary hemodynamics were not different at rest. Exercise was associated with a higher maximum total pulmonary vascular resistance, steeper mPAP-CO relationships, and lower α-coefficients in the blacks. These differences were entirely driven by higher slopes of mPAP-CO relationships (2.5 ± 0.7 vs. 1.4 ± 0.7 mmHg·l(-1)·min; P < 0.001) and lower α-coefficients (0.85 ± 0.33 vs. 1.35 ± 0.51%/mmHg; P < 0.01) in black men compared with white men. There were no differences in any of the hemodynamic variables between black and white women. In men only, the slopes of mPAP-CO relationships were inversely correlated to V̇o2max (P < 0.01). Thus the pulmonary circulation is intrinsically less distensible in black sub-Saharan African men compared with white Caucasian Europeans men, and this is associated with a lower exercise capacity. This study did not identify racial differences in pulmonary vascular function in women. Copyright © 2015 the American Physiological Society.

Optimizing functional exercise capacity in the elderly surgical population.

PubMed

Carli, Franco; Zavorsky, Gerald S

2005-01-01

There are several studies on the effect of exercise post surgery (rehabilitation), but few studies have looked at augmenting functional capacity prior to surgical admission (prehabilitation). A programme of prehabilitation is proposed in order to enhance functional exercise capacity in elderly patients with the intent to minimize the postoperative morbidity and accelerate postsurgical recovery. Few studies have looked at exercise prehabilitation to improve functional capacity prior to surgical admission. Prehabilitation prior to orthopaedic surgery does not seem to improve quality of life or recovery. However, prehabilitation prior to abdominal or cardiac surgery, based on 275 elderly patients, results in fewer postoperative complications, shorter postoperative length of stay, improved quality of life, and reduced declines in functional disability compared to sedentary controls. A concentrated 3-month progressive exercise prehabilitation programme consisting of aerobic training at 45-65% of maximal heart rate reserve (%HRR) along with periodic high-intensity interval training ( approximately 90% HRR) four times per week, 30-50 minutes per session, is recommended for improving cardiovascular functioning. A strength training programme of about 10 different exercises focused on large, multi-jointed muscle groups should also be implemented twice per week at a mean training intensity of 80% of one-repetition maximum. Finally, a minimum of 140 g ( approximately 560 kcal) of carbohydrate (CHO) should be taken 3 h before training to increase liver and muscle glycogen stores and a minimum of about 200 kcal of mixed protein-CHO should be ingested within 30 min following training to enhance muscle hypertrophy.

Is high-intensity interval training more effective on improving cardiometabolic risk and aerobic capacity than other forms of exercise in overweight and obese youth? A meta-analysis.

PubMed

García-Hermoso, A; Cerrillo-Urbina, A J; Herrera-Valenzuela, T; Cristi-Montero, C; Saavedra, J M; Martínez-Vizcaíno, V

2016-06-01

The scientific interest in high-intensity interval training (HIIT) has greatly increased during recent years. The objective of this meta-analysis was to determine the effectiveness of HIIT interventions on cardio-metabolic risk factors and aerobic capacity in overweight and obese youth, in comparison with other forms of exercise. A computerized search was made using seven databases. The analysis was restricted to studies that examined the effect of HIIT interventions on cardio-metabolic and/or aerobic capacity in pediatric obesity (6-17 years old). Nine studies using HIIT interventions were selected (n = 274). Standarized mean difference (SMD) and 95% confidence intervals were calculated. The DerSimonian-Laird approach was used. HIIT interventions (4-12 week duration) produced larger decreases in systolic blood pressure (SMD = 0.39; -3.63 mmHg) and greater increases in maximum oxygen uptake (SMD = 0.59; 1.92 ml/kg/min) than other forms of exercise. Also, type of comparison exercise group and duration of study were moderators. HIIT could be considered a more effective and time-efficient intervention for improving blood pressure and aerobic capacity levels in obese youth in comparison to other types of exercise. © 2016 World Obesity. © 2016 World Obesity.

Cross-training in birds: cold and exercise training produce similar changes in maximal metabolic output, muscle masses and myostatin expression in house sparrows (Passer domesticus).

PubMed

Zhang, Yufeng; Eyster, Kathleen; Liu, Jin-Song; Swanson, David L

2015-07-01

Maximal metabolic outputs for exercise and thermogenesis in birds presumably influence fitness through effects on flight and shivering performance. Because both summit (Msum, maximum thermoregulatory metabolic rate) and maximum (MMR, maximum exercise metabolic rate) metabolic rates are functions of skeletal muscle activity, correlations between these measurements and their mechanistic underpinnings might occur. To examine whether such correlations occur, we measured the effects of experimental cold and exercise training protocols for 3 weeks on body (Mb) and muscle (Mpec) masses, basal metabolic rate (BMR), Msum, MMR, pectoralis mRNA and protein expression for myostatin, and mRNA expression of TLL-1 and TLL-2 (metalloproteinase activators of myostatin) in house sparrows (Passer domesticus). Both training protocols increased Msum, MMR, Mb and Mpec, but BMR increased with cold training and decreased with exercise training. No significant differences occurred for pectoralis myostatin mRNA expression, but cold and exercise increased the expression of TLL-1 and TLL-2. Pectoralis myostatin protein levels were generally reduced for both training groups. These data clearly demonstrate cross-training effects of cold and exercise in birds, and are consistent with a role for myostatin in increasing pectoralis muscle mass and driving organismal increases in metabolic capacities. © 2015. Published by The Company of Biologists Ltd.

Effects of inhaled ipratropium bromide on breathing mechanics and gas exchange in exercising horses with chronic obstructive pulmonary disease.

PubMed

Bayly, W M; Duvivier, D H; Votion, D; Vandenput, S; Art, T; Lekeux, P

2002-01-01

Six Warmblood horses suffering an acute exacerbation of COPD were tested to investigate whether inhalation of ipratropium bromide (IB) dry powder (2,400 microg) 30 min preexercise would improve their exercise capacity. A cross-over protocol with an inert powder placebo (P) was used. Mechanics of breathing and arterial blood gases were determined before treatment, after treatment but pre-exercise, and during an incremental exercise test. Oxygen consumption (VO2) was also measured before and during exercise, and the time to fatigue recorded. Inhalation of IB reduced total pulmonary resistance (RL) and maximum intrapleural pressure changes (deltaPpl(max)) and increased dynamic compliance before exercise. The onset of exercise was associated with a marked decrease in RL in P-treated horses but not those receiving IB, so that RL during exercise was not affected by treatment. Although deltaPpl(max) was lower at 8,9 and 10 m/s with IB, there were no treatment-related changes in VO2, blood gases, time to fatigue or any other measurement of breathing mechanics. Therefore, although inhalation of IB prior to exercise may have improved deltaPpl(max), it had no apparent impact on the horses' capacity for exercise.

Multivisceral Transplantation Rehabilitation Program-Case Report.

PubMed

Loschi, T M; Cinacchi, M P R G; Baccan, M D T A; Marques, F; Pedroso, P T; Meira Filho, S P; Scacchetti, T; Pavão, D N

2018-04-01

Multivisceral transplantation is the treatment for multiple abdominal organ failure. The patient experiences reduced food intake and absorption of nutrients, contributing to weight loss and decreased muscle mass, reducing functional capacity. A physical and nutritional rehabilitation program based on adequate caloric intake associated with supervised physical exercise seems to support a gain of muscle mass, re-establishing its capacity and functional independence. A rehabilitation program was carried out, consisting of low-intensity aerobic exercise on treadmill, exercises of global strengthening (50% of 1 maximum repetition [1RM], with progressive increase), and nutritional monitoring (oral hypercaloric diet, hyperproteic supplementation daily and after exercise). Initial and final evaluation included weight, muscle mass index, brachial circumference (BC), tricipital cutaneous fold (TCF), hand grip strength (HGS), 6-minute walk test (6MWT), 1RM, vital capacity (VC), and respiratory muscle strength. After the program, functional capacity was evaluated through the 6MWT (92%), 1RM test, VC (55%), respiratory muscle strength, HGS at 5 kg, weight gain (4.75%), increase of BC in 2 cm, and TCF in 2 mm. The program contributed to functional independence, improved quality of life, and social reintegration, suggesting the importance of a supervised physical activity program associated with adequate nutritional intake after multivisceral transplantation. Copyright © 2018 Elsevier Inc. All rights reserved.

Small Airway Dysfunction and Abnormal Exercise Responses

PubMed Central

Petsonk, Edward L.; Stansbury, Robert C.; Beeckman-Wagner, Lu-Ann; Long, Joshua L.; Wang, Mei Lin

2016-01-01

Rationale Coal mine dust exposure can cause symptoms and loss of lung function from multiple mechanisms, but the roles of each disease process are not fully understood. Objectives We investigated the implications of small airway dysfunction for exercise physiology among a group of workers exposed to coal mine dust. Methods Twenty coal miners performed spirometry, first breathing air and then helium-oxygen, single-breath diffusing capacity, and computerized chest tomography, and then completed cardiopulmonary exercise testing. Measurements and Main Results Six participants meeting criteria for small airway dysfunction were compared with 14 coal miners who did not. At submaximal workload, miners with small airway dysfunction used a higher proportion of their maximum voluntary ventilation and had higher ventilatory equivalents for both O2 and CO2. Regression modeling indicated that inefficient ventilation was significantly related to small airway dysfunction but not to FEV1 or diffusing capacity. At the end of exercise, miners with small airway dysfunction had 27% lower O2 consumption. Conclusions Small airway abnormalities may be associated with important inefficiency of exercise ventilation. In dust-exposed individuals with only mild abnormalities on resting lung function tests or chest radiographs, cardiopulmonary exercise testing may be important in defining causes of exercise intolerance. PMID:27073987

Effects of maximum intensity aerobic swimming exercise until exhaustion at different times of day on the hematological parameters in rats.

PubMed

Beck, W; Gobatto, Claudio Alexandre

2013-12-01

The aims of this study were: a) to analyze the time of day effect on the aerobic capacity and time to exhaustion at aerobic capacity intensity (TE), and b) to analyze the physiological impact of handling and exercise testing during the light and dark periods, based on hematological parameters. Eighty rats were randomly divided into two control groups (C12 and C20) and two exercise groups (E12 and E20), assessed at 12:00 h (C12 and E12) or 20:00 h (C20 and E20). The lactate minimum intensity (LMi) was measured and after 48 h the exercise groups were subjected to a bout of swimming until exhaustion at LMi (TE). The TE was 1.30 ± 0.51 h for the E12 group and 1.81 ± 0.77 h for the E20 group (p = 0.03). The time of day effect was significant for all white blood cell counts (12:00 h > 20:00 h). Chronic handling and performing exercise tests at 12:00 h (light period) resulted in an increased WBC counts and decreased exercise tolerance. The favorable time of day for aerobic capacity and performance assessment and hematological parameters was at 20:00 h (dark period), which is associated with the wakefulness period of the assessed animals.

The Impact of a Multidimensional Exercise Intervention on Physical and Functional Capacity, Anxiety, and Depression in Patients With Advanced-Stage Lung Cancer Undergoing Chemotherapy.

PubMed

Quist, Morten; Adamsen, Lis; Rørth, Mikael; Laursen, Jørgen H; Christensen, Karl B; Langer, Seppo W

2015-07-01

Patients with advanced-stage lung cancer face poor survival and experience co-occurring chronic physical and psychosocial symptoms. Despite several years of research in exercise oncology, few exercise studies have targeted advanced lung cancer patients undergoing chemotherapy. The aim of the present study was to investigate the benefits of a 6-week supervised group exercise intervention and to outline the effect on aerobic capacity, strength, health-related quality of life (HRQoL), anxiety, and depression. VO2peak was assessed using an incremental exercise test. Muscle strength was measured with one repetition maximum test (1RM). HRQoL, anxiety, and depression were assessed using Functional Assessment of Cancer Therapy-Lung (FACT-L) scale and the Hospital Anxiety and Depression Scale (HADS). One hundred and forthteen patients with advanced stage lung cancer were recruited. Forty-three patients dropped out. No serious adverse events were reported. Exercise adherence in the group training was 68%. Improvements in VO2peak (P < .001) and 6-minute walk distance (P < .001) and muscle strength measurements (P < .05) were seen. There was a reduction in anxiety level (P = .0007) and improvement in the emotional well-being parameter (FACT-L) but no statistically significant changes in HRQoL were observed. The results of the present study show that during a 6-week hospital-based supervised, structured, and group-based exercise program, patients with advanced-stage lung cancer (NSCLC IIIb-IV, ED-SCLC) improve their physical capacity (VO2peak, 1RM), functional capacity, anxiety level, and emotional well-being, but not their overall HRQoL. A randomized controlled trial testing the intervention including 216 patients is currently being carried out. © The Author(s) 2015.

A comparison between computer-controlled and set work rate exercise based on target heart rate

NASA Technical Reports Server (NTRS)

Pratt, Wanda M.; Siconolfi, Steven F.; Webster, Laurie; Hayes, Judith C.; Mazzocca, Augustus D.; Harris, Bernard A., Jr.

1991-01-01

Two methods are compared for observing the heart rate (HR), metabolic equivalents, and time in target HR zone (defined as the target HR + or - 5 bpm) during 20 min of exercise at a prescribed intensity of the maximum working capacity. In one method, called set-work rate exercise, the information from a graded exercise test is used to select a target HR and to calculate a corresponding constant work rate that should induce the desired HR. In the other method, the work rate is controlled by a computer algorithm to achieve and maintain a prescribed target HR. It is shown that computer-controlled exercise is an effective alternative to the traditional set work rate exercise, particularly when tight control of cardiovascular responses is necessary.

Effects of body position on exercise capacity and pulmonary vascular pressure-flow relationships.

PubMed

Forton, Kevin; Motoji, Yoshiki; Deboeck, Gael; Faoro, Vitalie; Naeije, Robert

2016-11-01

There has been revival of interest in exercise testing of the pulmonary circulation for the diagnosis of pulmonary vascular disease, but there still is uncertainty about body position and the most relevant measurements. Doppler echocardiography pulmonary hemodynamic measurements were performed at progressively increased workloads in 26 healthy adult volunteers in supine, semirecumbent, and upright positions that were randomly assigned at 24-h intervals. Mean pulmonary artery pressure (mPAP) was estimated from the maximum tricuspid regurgitation jet velocity. Cardiac output was calculated from the left ventricular outflow velocity-time integral. Pulmonary vascular distensibility α-index, the percent change of vessel diameter per millimeter mercury of mPAP, was calculated from multipoint mPAP-cardiac output plots. Body position did not affect maximum oxygen uptake (Vo 2max ), maximum respiratory exchange ratio, ventilatory equivalent for carbon dioxide, or slope of mPAP-cardiac output relationships, which was on average of 1.5 ± 0.4 mmHg·l -1 ·min -1 Maximum mPAP, cardiac output, and total pulmonary vascular resistance were, respectively, 34 ± 4 mmHg, 18 ± 3 l/min, and 1.9 ± 0.3 Wood units. However, the semirecumbent position was associated with a 10% decrease in maximum workload. Furthermore, cardiac output-workload or cardiac output-Vo 2 relationships were nonlinear and variable. These results suggest that body position does not affect maximum exercise testing of the pulmonary circulation when results are expressed as mPAP-cardiac output or maximum total pulmonary vascular resistance. Maximum workload is decreased in semirecumbent compared with upright exercise. Workload or Vo 2 cannot reliably be used as surrogates for cardiac output. Copyright © 2016 the American Physiological Society.

Effects of insulin resistance on skeletal muscle growth and exercise capacity in type 2 diabetic mouse models

PubMed Central

Ostler, Joseph E.; Maurya, Santosh K.; Dials, Justin; Roof, Steve R.; Devor, Steven T.; Ziolo, Mark T.

2014-01-01

Type 2 diabetes mellitus is associated with an accelerated muscle loss during aging, decreased muscle function, and increased disability. To better understand the mechanisms causing this muscle deterioration in type 2 diabetes, we assessed muscle weight, exercise capacity, and biochemistry in db/db and TallyHo mice at prediabetic and overtly diabetic ages. Maximum running speeds and muscle weights were already reduced in prediabetic db/db mice when compared with lean controls and more severely reduced in the overtly diabetic db/db mice. In contrast to db/db mice, TallyHo muscle size dramatically increased and maximum running speed was maintained during the progression from prediabetes to overt diabetes. Analysis of mechanisms that may contribute to decreased muscle weight in db/db mice demonstrated that insulin-dependent phosphorylation of enzymes that promote protein synthesis was severely blunted in db/db muscle. In addition, prediabetic (6-wk-old) and diabetic (12-wk-old) db/db muscle exhibited an increase in a marker of proteasomal protein degradation, the level of polyubiquitinated proteins. Chronic treadmill training of db/db mice improved glucose tolerance and exercise capacity, reduced markers of protein degradation, but only mildly increased muscle weight. The differences in muscle phenotype between these models of type 2 diabetes suggest that insulin resistance and chronic hyperglycemia alone are insufficient to rapidly decrease muscle size and function and that the effects of diabetes on muscle growth and function are animal model-dependent. PMID:24425761

Quantifying the history dependency of muscle recovery from a fatiguing intermittent task.

PubMed

Rashedi, Ehsan; Nussbaum, Maury A

2017-01-25

Muscle fatigue and recovery are complex processes influencing muscle force generation capacity. While fatigue reduces this capacity, recovery acts to restore the unfatigued muscle state. Many factors can potentially affect muscle recovery, and among these may be a task dependency of recovery following an exercise. However, little has been reported regarding the history dependency of recovery after fatiguing contractions. We examined the dependency of muscle recovery subsequent to four different histories of fatiguing muscle contractions, imposed using two cycle times (30 and 60s) during low to moderate levels (15% and 25% of maximum voluntary contraction (MVC)) of intermittent static exertions involving index finger abduction. MVC and low-frequency electrical stimulation (LFES) measures (i.e., magnitude, rise and relaxation rates) of muscle capacity were used, all of which indicated a dependency of muscle recovery on the muscle capacity state existing immediately after fatiguing exercise. This dependency did not appear to be modified by either the cycle time or exertion level leading to that state. These results imply that the post-exercise rate of recovery is primarily influenced by the immediate post-exercise muscle contractile status (estimated by MVC and LFES measures). Such results may help improve existing models of muscle recovery, facilitating more accurate predictions of localized muscle fatigue development and thereby helping to enhance muscle performance and reduce the risk of injury. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effect of 1 Repetition Maximum, 80% Repetition Maximum, and 50% Repetition Maximum Strength Exercise in Trained Individuals on Variations in Plasma Redox Biomarkers.

PubMed

Polotow, Tatiana G; Souza-Junior, Tácito P; Sampaio, Ricardo C; Okuyama, Alexandre R; Ganini, Douglas; Vardaris, Cristina V; Alves, Ragami C; McAnulty, Steven R; Barros, Marcelo P

2017-09-01

Polotow, TG, Souza-Junior, TP, Sampaio, RC, Okuyama, AR, Ganini, D, Vardaris, CV, Alves, RC, McAnulty, SR, and Barros, MP. Effect of 1RM, 80%RM, and 50%RM strength exercise in trained individuals on variations in plasma redox biomarkers. J Strength Cond Res 31(9): 2489-2497, 2017-For decades, scientists have examined the participation of oxygen/nitrogen species in anaerobic-like exercises, especially weightlifting and resistance exercises. The balance between the production of oxyradicals and antioxidant responses during anaerobic-like exercises is essential to assure adaptation to the physiological benefits of strength training and to prevent chronic harmful effects. The aim of this study is to examine the hypothesis that different weight loads (1 repetition maximum (RM), 80%RM, and 50%RM) lifted until exhaustion could impose distinct oxidative insults and elicit diverse antioxidant responses in plasma of young trained subjects. Glucose (+10%), lactate (+65%), urea (+30%), free iron (+65%), reduced/oxidized glutathione (+14 and +23%, respectively), and xanthine oxidase activity (2.2-fold) significantly increased after the 1RM test, whereas plasma antioxidant capacity dropped by 37%. When lower weight loads were applied (80%RM and 50%RM tests), heme-iron (+15 and +20%, respectively) became the prevalent pro-oxidant, although glutathione responses were only detected after 80%RM (+14%). Lactate concentration in plasma continuously increased, by 2.9-fold (80%RM) and 3.6-fold higher (50%RM test). We demonstrated that 1RM tests significantly diminish the antioxidant capacity of plasma because of iron overload, whereas 80%RM tests require higher involvement of glutathione molecules to counteract heme-iron oxidative insult. Mild redox imbalances promoted by heme-iron were found in plasma after 50%RM. Although we did not observe overall changes in muscle damage in young trained subjects, we cannot exclude the need for specific antioxidant supplementation depending on the strength protocols applied, especially for less responsive groups, such as sedentary and elderly populations.

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.

A home-based program using patterned sensory enhancement improves resistance exercise effects for children with cerebral palsy: a randomized controlled trial.

PubMed

Wang, Tze-Hsuan; Peng, Yi-Chun; Chen, Yu-Ling; Lu, Tung-Wu; Liao, Hua-Fang; Tang, Pei-Fang; Shieh, Jeng-Yi

2013-10-01

Neurologic music therapy has demonstrated improved walking performance in persons with neurologic disease; however, little evidence supports the use of music with functional resistance exercise to improve motor capacity and daily functions for children with cerebral palsy. To investigate the effect of additional patterned sensory enhancement (PSE) music combined with exercise for children with spastic diplegia. An assessor-blind, randomized controlled trial with 6- and 12-week follow-ups was carried out. Thirty-six children with spastic diplegia, aged 5 to 13 years, were assigned to a PSE group (n = 18) or a no-music group (n = 18). Both groups received 6-week, home-based, loaded sit-to-stand exercise, but only the PSE group exercised with prerecorded PSE music. The primary outcome was Gross Motor Function Measure (GMFM). Secondary outcomes included Pediatric Evaluation of Disability Inventory (PEDI) mobility and self-care domains, 1-repetition maximum of sit-to-stand, and walking speeds. Three children did not complete the program. Intention-to-treat analysis showed both groups improved in GMFM D, E, and Goal dimensions; Functional Skills Scales of PEDI mobility domain; and 1-repetition maximum of sit-to-stand at posttest and follow-ups (P ≤ .005). The PSE group improved significantly greater than the no-music group in the GMFM D and Goal dimensions (P < .005) after training, and the improvement persisted for at least 6 or 12 weeks (P ≤ .013). No significant improvements in the rest PEDI scales and walking speeds were found. Adding neurologic music therapy to functional resistance exercise could induce greater improvements in gross motor capacity for children with cerebral palsy.

Pulmonary Vascular Response Patterns During Exercise in Left Ventricular Systolic Dysfunction Predict Exercise Capacity and Outcomes

PubMed Central

Lewis, Gregory D.; Murphy, Ryan M.; Shah, Ravi V.; Pappagianopoulos, Paul P.; Malhotra, Rajeev; Bloch, Kenneth D.; Systrom, David M.; Semigran, Marc J.

2012-01-01

Background Elevated resting pulmonary arterial pressure (PAP) in patients with left ventricular systolic dysfunction (LVSD) purports a poor prognosis. However, PAP response patterns to exercise in LVSD and their relationship to functional capacity and outcomes have not been characterized. Methods and Results Sixty consecutive patients with LVSD (age 60±12 years, LV ejection fraction 0.31±0.07, mean±SD) and 19 controls underwent maximum incremental cardiopulmonary exercise testing with simultaneous hemodynamic monitoring. During low-level exercise (30 Watts), LVSD subjects compared to controls, had greater augmentation in mean PAPs (15±1 vs. 5±1 mmHg), transpulmonary gradients (5±1 vs. 1±1 mmHg), and effective PA elastance (0.05±0.02 vs. −0.03±0.01 mmHg/ml, p<0.0001 for all). A linear increment in PAP relative to work (0.28±0.12 mmHg/watt) was observed in 65% of LVSD patients, which exceeded that observed in controls (0.07±0.02 mmHg/watt, P<0.0001). Exercise capacity and survival was worse in patients with a PAP/watt slope above the median than in patients with a lower slope. In the remaining 35% of LVSD patients, exercise induced a steep initial increment in PAP (0.41±0.16 mmHg/watt) followed by a plateau. The plateau pattern, compared to a linear pattern, was associated with reduced peak VO2 (10.6±2.6 vs. 13.1±4.0 ml/kg/min, P=0.005), lower right ventricular stroke work index augmentation with exercise (5.7±3.8 vs. 9.7±5.0 g/m2, P=0.002), and increased mortality (HR 8.1, 95% CI 2.7-23.8, P<0.001). Conclusions A steep increment in PAP during exercise and failure to augment PAP throughout exercise are associated with decreased exercise capacity and survival in patients with LVSD, and may therefore represent therapeutic targets. Clinical Trial Information URL: http://www.clinicaltrials.gov. Unique Identifier: NCT00309790) PMID:21292991

Muscle glycogen depletion and subsequent replenishment affect anaerobic capacity of horses.

PubMed

Lacombe, V A; Hinchcliff, K W; Geor, R J; Baskin, C R

2001-10-01

The purpose of this study was to determine the effect of muscle glycogen depletion and subsequent replenishment on anaerobic capacity of horses. In a blinded crossover study, seven fit horses performed glycogen-depleting exercise on two occasions. Horses were infused after glycogen-depleting exercise with either 6 g/kg body wt of glucose as a 13.5% solution in 0.9% NaCl (Glu) or with 0.9% NaCl (Sal) of equivalent volume. Subsequently, horses performed a high-speed exercise test (120% of maximal rate of oxygen consumption) to estimate maximum accumulated oxygen deficit. Replenishment of muscle glycogen was greater (P < 0.05) in Glu [from 24.7 +/- 7.2 (SE) to 116.5 +/- 7 mmol/kg wet wt before and after infusion, respectively] than in Sal (from 23.4 +/- 7.2 to 47.8 +/- 5.7 mmol/kg wet wt before and after infusion, respectively). Run time to fatigue during the high-speed exercise test (97.3 +/- 8.2 and 70.8 +/- 8.3 s, P < 0.05), maximal accumulated oxygen deficit (105.7 +/- 9.3 and 82.4 +/- 10.3 ml O(2) equivalent/kg, P < 0.05), and blood lactate concentration at the end of the high-speed exercise test (11.1 +/- 1.4 and 9.2 +/- 3.7 mmol/l, P < 0.05) were greater for Glu than for Sal, respectively. We concluded that decreased availability of skeletal muscle glycogen stores diminishes anaerobic power generation and capacity for high-intensity exercise in horses.

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

Physical exercises on a bicycle-ergometer and running track to prevent hypodynamia in workers of intellectual labor

NASA Technical Reports Server (NTRS)

Vasilyeva, V. V.; Korableva, Y. N.; Trunin, V. V.

1980-01-01

A program of exercises was developed and tested, consisting of a 12 minute session on a variable load bicycle ergometer and a 10-11 min. run with brief stretching and resting sessions between. Physical performance capacity was measured before, during, and after the period of the experiment and physical exams conducted. After a 4 month test period involving 30 men, aged 25-35, the program was found to be successful in increasing physical performance capacity. The PWC170 increased an average of 22 percent and maximum oxygen consumption 14 percent. Arterial pressure dropped (120/75 to 114/68), vital capacity of lungs increased by 6 percent, strength of respiratory muscles by 8.8 percent, duration of respiratory delay by 18 percent. Duration of cardiac cycles increased, stress index decreased. Cardiac contraction rate 2 minutes after work on the ergometer decreased from 118 to 102 bt/min.

Pneumatic strength assessment device: design and isometric measurement.

PubMed

Paulus, David C; Reiser, Raoul F; Troxell, Wade O

2004-01-01

In order to load a muscle optimally during resistance exercise, it should be heavily taxed throughout the entire range of motion for that exercise. However, traditional constant resistance squats only tax the lower-extremity muscles to their limits at the "sticking region" or a critical joint configuration of the exercise cycle. Therefore, a linear motion (Smith) exercise machine was modified with pneumatics and appropriate computer control so that it could be capable of adjusting force to control velocity within a repetition of the squat exercise or other exercise performed with the device. Prior to application of this device in a dynamic squat setting, the maximum voluntary isometric force (MVIF) produced over a spectrum of knee angles is needed. This would reveal the sticking region and overall variation in strength capacity. Five incremental knee angles (90, 110, 130, 150, and 170 degrees, where 180 degrees defined full extension) were examined. After obtaining university-approved informed consent, 12 men and 12 women participated in the study. The knee angle was set, and the pneumatic cylinder was pressurized such that the subject could move the barbell slightly but no more than two-centimeters. The peak pressure exerted over a five-second maximum effort interval was recorded at each knee angle in random order and then repeated. The average of both efforts was then utilized for further analysis. The sticking region occurred consistently at a 90 degrees knee angle, however, the maximum force produced varied between 110 degrees and 170 degrees with the greatest frequency at 150 degrees for both men and women. The percent difference between the maximum and minimum MVIF was 46% for men and 57% for women.

Effect of antioxidant supplementation on exercise-induced cardiac troponin release in cyclists: a randomized trial.

PubMed

Klinkenberg, Lieke J J; Res, Peter T; Haenen, Guido R; Bast, Aalt; van Loon, Luc J C; van Dieijen-Visser, Marja P; Meex, Steven J R

2013-01-01

Cardiac troponin is the biochemical gold standard to diagnose acute myocardial infarction. Interestingly however, elevated cardiac troponin concentrations are also frequently observed during and after endurance-type exercise. Oxidative stress associated with prolonged exercise has been proposed to contribute to cardiac troponin release. Therefore, the aim of this study was to assess the effect of 4 week astaxanthin supplementation (a potent cartenoid antioxidant) on antioxidant capacity and exercise-induced cardiac troponin release in cyclists. Thirty-two well-trained male cyclists (age 25±5, weight 73±7 kg, maximum O2 uptake 60±5 mL·kg(-1)·min(-1), Wmax 5.4±0.5 W·kg(-1); mean ± SD) were repeatedly subjected to a laboratory based standardized exercise protocol before and after 4 weeks of astaxanthin (20 mg/day), or placebo supplementation in a double-blind randomized manner. Blood samples were obtained at baseline, at 60 min of cycling and immediately post-exercise (≈ 120 min). The pre-supplementation cycling trial induced a significant rise of median cardiac troponin T concentrations from 3.2 (IQR 3.0-4.2) to 4.7 ng/L (IQR 3.7-6.7), immediately post-exercise (p<0.001). Four weeks of astaxanthin supplementation significantly increased mean basal plasma astaxanthin concentrations from non-detectable values to 175±86 µg·kg(-1). However, daily astaxanthin supplementation had no effect on exercise-induced cardiac troponin T release (p = 0.24), as measured by the incremental area under the curve. Furthermore, the elevation in basal plasma astaxanthin concentrations was not reflected in changes in antioxidant capacity markers (trolox equivalent antioxidant capacity, uric acid, and malondialdehyde). Markers of inflammation (high-sensitivity C-reactive protein) and exercise-induced skeletal muscle damage (creatine kinase) were equally unaffected by astaxanthin supplementation. Despite substantial increases in plasma astaxanthin concentrations, astaxanthin supplementation did not improve antioxidant capacity in well-trained cyclists. Accordingly, exercise-induced cardiac troponin T concentrations were not affected by astaxanthin supplementation. ClinicalTrials.gov NCT01241877.

Separate and combined effects of exposure to heat stress and mental fatigue on endurance exercise capacity in the heat.

PubMed

Otani, Hidenori; Kaya, Mitsuharu; Tamaki, Akira; Watson, Phillip

2017-01-01

This study investigated the effects of exposure to pre-exercise heat stress and mental fatigue on endurance exercise capacity in a hot environment. Eight volunteers completed four cycle exercise trials at 80% maximum oxygen uptake until exhaustion in an environmental chamber maintained at 30 °C and 50% relative humidity. The four trials required them to complete a 90 min pre-exercise routine of either a seated rest (CON), a prolonged demanding cognitive task to induce mental fatigue (MF), warm water immersion at 40 °C during the last 30 min to induce increasing core temperature (WI), or a prolonged demanding cognitive task and warm water immersion at 40 °C during the last 30 min (MF + WI). Core temperature when starting exercise was higher following warm water immersion (~38 °C; WI and MF + WI) than with no water immersion (~36.8 °C; CON and MF, P < 0.001). Self-reported mental fatigue when commencing exercise was higher following cognitive task (MF and MF + WI) than with no cognitive task (CON and WI; P < 0.05). Exercise time to exhaustion was reduced by warm water immersion (P < 0.001) and cognitive task (P < 0.05). Compared with CON (18 ± 7 min), exercise duration reduced 0.8, 26.6 and 46.3% in MF (17 ± 7 min), WI (12 ± 5 min) and MF + WI (9 ± 3 min), respectively. This study demonstrates that endurance exercise capacity in a hot environment is impaired by either exposure to pre-exercise heat stress or mental fatigue, and this response is synergistically increased during combined exposure to them.

The Effect of Aerobic or Aerobic-Strength Exercise on Body Composition and Functional Capacity in Patients with BMI ≥35 after Bariatric Surgery: a Randomized Control Trial.

PubMed

Hassannejad, Alireza; Khalaj, Alireza; Mansournia, Mohammad Ali; Rajabian Tabesh, Mastaneh; Alizadeh, Zahra

2017-11-01

Although previous studies suggested that bariatric surgery is the most effective and sustainable treatment method for morbid obesity in long term, but without changing in lifestyle, maintaining optimal weight loss is almost impossible. Sixty morbid obese patients (BMI ≥ 35) were evaluated before and after 12 weeks of bariatric surgery in order to compare the impact of two different exercise programs on body composition and functional capacity outcomes. Participants were divided into three groups: aerobic (A), aerobic-strength (AS), and control (C) group. Aerobic capacity was assessed with 12-min walk-run test (12MWRT). One-repetition maximum (1RM) test was performed to evaluation upper limb muscle strength. Lower extremity functional capacity was assessed by sit-to-stand test. Weight, percent body fat (PBF), and fat mass (FM) reduced greater in the trial groups in comparison to the C group (P < 0.05). In the AS group, the reduction of fat-free mass (FFM) was significantly lower than that in the other groups. Mean changes in 12MWRT increased significantly in the intervention groups. The mean change in the sit-to-stand scores was not statistically significant between the three groups. Comparing the intervention groups showed that mean changes in 1RM variables increased in AS group (P = 0.03). The data suggests a positive effect of exercise on weight and PBF decrease after surgery, and it leads to significant improvement on aerobic capacity. Moreover, doing resisted exercise caused greater preserving of lean mass.

Walking performance in people with diabetic neuropathy: benefits and threats.

PubMed

Kanade, R V; van Deursen, R W M; Harding, K; Price, P

2006-08-01

Walking is recommended as an adjunct therapy to diet and medication in diabetic patients, with the aim of improving physical fitness, glycaemic control and body weight reduction. Therefore we evaluated walking activity on the basis of capacity, performance and potential risk of plantar injury in the diabetic population before it can be prescribed safely. Twenty-three subjects with diabetic neuropathy (DMPN) were compared with 23 patients with current diabetic foot ulcers, 16 patients with partial foot amputations and 22 patients with trans-tibial amputations. The capacity for walking was measured using a total heart beat index (THBI). Gait velocity and average daily strides were measured to assess the performance of walking, and its impact on weight-bearing was studied using maximum peak pressure. THBI increased (p<0.01) and gait velocity and daily stride count fell (p<0.001 for both) with progression of foot complications. The maximum peak pressures over the affected foot of patients with diabetic foot ulcers (p<0.05) and partial foot amputations (p<0.01) were higher than in the group with DMPN. On the contralateral side, the diabetic foot ulcer group showed higher maximum peak pressure over the total foot (p<0.05), and patients with partial foot amputations (p<0.01) and trans-tibial amputations (p<0.05) showed higher maximum peak pressure over the heel. Walking capacity and performance decrease with progression of foot complications. Although walking is recommended to improve fitness, it cannot be prescribed in isolation, considering the increased risk of plantar injury. For essential walking we therefore recommend the use of protective footwear. Walking exercise should be supplemented by partial or non-weight-bearing exercises to improve physical fitness in diabetic populations.

Effects of exercise and conditioning on clotting and fibrinolytic activity in men

NASA Technical Reports Server (NTRS)

Ferguson, Earl W.; Bernier, Lani L.; Banta, Guy R.; Yu-Yahiro, Janet; Schoomaker, Eric B.

1987-01-01

Blood clotting and fibrinolytic activity in three groups of nonsmoking, nonobese, healthy men ranging from 19 to 59 years are studied. The groups consisted of (1) marathoners (men running more than 50 miles/week); (2) joggers (men running 5-15 miles/week; and (3) sedentary subjects (men who did not exercise routinely). It is observed that the rate of blood clotting is accelerated by exercise; marathoners had greater increases in fibrinolytic activity than the other two groups; and fibrin degradation products increased with exercise. The data reveal that the changes in clotting assays with exercise do not correlate with changes in whole blood lactate, blood pyruvate, or rectal temperatures. It is noted that the level of acceleration for fibrinolytic activity is directly related to the maximum aerobic capacity and work load of the individual, and that conditioning enhances the fibrinolytic response to exercise.

Respiratory muscle stretch gymnastics in patients with post coronary artery bypass grafting pain: impact on respiratory muscle function, activity, mood and exercise capacity.

PubMed

Aida, Nobuko; Shibuya, Masako; Yoshino, Katsuki; Komoda, Masaji; Inoue, Tomoko

2002-12-01

A new rehabilitation (New-RH) program including respiratory muscle stretch gymnastics (RMSG) was developed to alleviate post-coronary artery bypass grafting pain (PCP). Effects on respiratory muscle function, pain, activities of daily living (ADL), mood and exercise capacity were investigated. Subjects were 16 consecutive patients undergoing median full sternotomy coronary artery bypass grafting (CABG), and were randomly divided into equal New-RH (S-group) and conventional therapy (C-group) groups. Rib cage dominant breathing was observed postoperatively in both groups. With preoperative tan deltaVrc/deltaVab, increases at 1-week postoperatively and decreases at discharge for S-group tended to exceed those of C-group (p > .05). Decreased maximum inspiratory and expiratory pressure status for functional residual capacity and percent forced expiratory volume in one second at discharge again only tended to be smaller for S-group (p > .05). S-group displayed significantly reduced pain around both scapulas at discharge (p = .049), and increased mean overall ADL and profile of mood states (POMS)/Vigor scores (p = .031 and p = .018, respectively). POMS/Tension-Anxiety scores at discharge for S-group were significantly smaller than those preoperatively (p = .025), and S-group displayed significantly increased distance walked over 6-minutes at discharge than C-group (p = .029). New-RH improves patient participation in exercise therapy and increases exercise capacity by reducing PCP, relieving anxiety and tension, and improving ADL.

Safety and efficacy of exercise training in adults with Pompe disease: evalution of endurance, muscle strength and core stability before and after a 12 week training program.

PubMed

van den Berg, Linda E M; Favejee, Marein M; Wens, Stephan C A; Kruijshaar, Michelle E; Praet, Stephan F E; Reuser, Arnold J J; Bussmann, Johannes B J; van Doorn, Pieter A; van der Ploeg, Ans T

2015-07-19

Pompe disease is a proximal myopathy. We investigated whether exercise training is a safe and useful adjuvant therapy for adult Pompe patients, receiving enzyme replacement therapy. Training comprised 36 sessions of standardized aerobic, resistance and core stability exercises over 12 weeks. Before and after, the primary outcome measures safety, endurance (aerobic exercise capacity and distance walked on the 6 min walk test) and muscle strength, and secondary outcome measures core stability, muscle function and body composition, were evaluated. Of 25 patients enrolled, 23 successfully completed the training. Improvements in endurance were shown by increases in maximum workload capacity (110 W before to 122 W after training, [95 % CI of the difference 6 · 0 to 19 · 7]), maximal oxygen uptake capacity (69 · 4 % and 75 · 9 % of normal, [2 · 5 to 10 · 4]), and maximum walking distance (6 min walk test: 492 meters and 508, [-4 · 4 to 27 · 7] ). There were increases in muscle strength of the hip flexors (156 · 4 N to 180 · 7 N [1 · 6 to 13 · 6) and shoulder abductors (143 · 1 N to 150 · 7 N [13 · 2 to 35 · 2]). As an important finding in secondary outcome measures the number of patients who were able to perform the core stability exercises rose, as did the core stability balancing time (p < 0.05, for all four exercises). Functional tests showed small reductions in the time needed to climb four steps (2 · 4 sec to 2 · 1, [- 0 · 54 to -0 · 04 ]) and rise to standing position (5 · 8 sec to 4 · 8, [-2 · 0 to 0 · 0]), while time to run, the quick motor function test results and body composition remained unchanged. Our study shows that a combination of aerobic, strength and core stability exercises is feasible, safe and beneficial to adults with Pompe disease.

CFTR Genotype and Maximal Exercise Capacity in Cystic Fibrosis: A Cross-sectional Study.

PubMed

Radtke, Thomas; Hebestreit, Helge; Gallati, Sabina; Schneiderman, Jane E; Braun, Julia; Stevens, Daniel; Hulzebos, Erik Hj; Takken, Tim; Boas, Steven R; Urquhart, Don S; Lands, Larry C; Tejero, Sergio; Sovtic, Aleksandar; Dwyer, Tiffany; Petrovic, Milos; Harris, Ryan A; Karila, Chantal; Savi, Daniela; Usemann, Jakob; Mei-Zahav, Meir; Hatziagorou, Elpis; Ratjen, Felix; Kriemler, Susi

2018-02-01

Cystic fibrosis transmembrane conductance regulator (CFTR) is expressed in human skeletal muscle cells. Variations of CFTR dysfunction among patients with cystic fibrosis may be an important determinant of maximal exercise capacity in cystic fibrosis. Previous studies on the relationship between CFTR genotype and maximal exercise capacity are scarce and contradictory. This study was designed to explore factors influencing maximal exercise capacity, expressed as peak oxygen uptake (V.O2peak), with a specific focus on CFTR genotype in children and adults with cystic fibrosis. In an international, multicenter, cross-sectional study, we collected data on CFTR genotype and cardiopulmonary exercise tests in patients with cystic fibrosis who were ages 8 years and older. CFTR mutations were classified into functional classes I–V. The final analysis included 726 patients (45% females; age range, 8–61 yr; forced expiratory volume in 1 s, 16 to 123% predicted) from 17 cystic fibrosis centers in North America, Europe, Australia, and Asia, all of whom had both valid maximal cardiopulmonary exercise tests and complete CFTR genotype data. Overall, patients exhibited exercise intolerance (V.O2peak, 77.3 ± 19.1% predicted), but values were comparable among different CFTR classes. We did not detect an association between CFTR genotype functional classes I–III and either V.O2peak (percent predicted) (adjusted β = −0.95; 95% CI, −4.18 to 2.29; P = 0.57) or maximum work rate (Wattmax) (adjusted β = −1.38; 95% CI, −5.04 to 2.27; P = 0.46) compared with classes IV–V. Those with at least one copy of a F508del-CFTR mutation and one copy of a class V mutation had a significantly lower V.O2peak (β = −8.24%; 95% CI, −14.53 to −2.99; P = 0.003) and lower Wattmax (adjusted β = −7.59%; 95% CI, −14.21 to −0.95; P = 0.025) than those with two copies of a class II mutation. On the basis of linear regression analysis adjusted for relevant confounders, lung function and body mass index were associated with V.O2peak. CFTR functional genotype class was not associated with maximal exercise capacity in patients with cystic fibrosis overall, but those with at least one copy of a F508del-CFTR mutation and a single class V mutation had lower maximal exercise capacity.

Exercise and sports science Australia (ESSA) position statement on exercise and spinal cord injury.

PubMed

Tweedy, Sean M; Beckman, Emma M; Geraghty, Timothy J; Theisen, Daniel; Perret, Claudio; Harvey, Lisa A; Vanlandewijck, Yves C

2017-02-01

Traumatic spinal cord injury (SCI) may result in tetraplegia (motor and/or sensory nervous system impairment of the arms, trunk and legs) or paraplegia (motor and/or sensory impairment of the trunk and/or legs only). The adverse effects of SCI on health, fitness and functioning are frequently compounded by profoundly sedentary behaviour. People with paraplegia (PP) and tetraplegia (TP) have reduced exercise capacity due to paralysis/paresis and reduced exercising stroke volume. TP often further reduces exercise capacity due to lower maximum heart-rate and respiratory function. There is strong, consistent evidence that exercise can improve cardiorespiratory fitness and muscular strength in people with SCI. There is emerging evidence for a range of other exercise benefits, including reduced risk of cardio-metabolic disease, depression and shoulder pain, as well as improved respiratory function, quality-of-life and functional independence. Exercise recommendations for people with SCI are: ≥30min of moderate aerobic exercise on ≥5d/week or ≥20min of vigorous aerobic ≥3d/week; strength training on ≥2d/week, including scapula stabilisers and posterior shoulder girdle; and ≥2d/week flexibility training, including shoulder internal and external rotators. These recommendations may be aspirational for profoundly inactive clients and stratification into "beginning", "intermediate" and "advanced" will assist application of the recommendations in clinical practice. Flexibility exercise is recommended to preserve upper limb function but may not prevent contracture. For people with TP, Rating of Perceived Exertion may provide a more valid indication of exercise intensity than heart rate. The safety and effectiveness of exercise interventions can be enhanced by initial screening for autonomic dysreflexia, orthostatic hypotension, exercise-induced hypotension, thermoregulatory dysfunction, pressure sores, spasticity and pain. Copyright © 2016 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Exercise-induced bronchoconstriction alters airway nitric oxide exchange in a pattern distinct from spirometry.

PubMed

Shin, Hye-Won; Schwindt, Christina D; Aledia, Anna S; Rose-Gottron, Christine M; Larson, Jennifer K; Newcomb, Robert L; Cooper, Dan M; George, Steven C

2006-12-01

Exhaled nitric oxide (NO) is altered in asthmatic subjects with exercise-induced bronchoconstriction (EIB). However, the physiological interpretation of exhaled NO is limited because of its dependence on exhalation flow and the inability to distinguish completely proximal (large airway) from peripheral (small airway and alveolar) contributions. We estimated flow-independent NO exchange parameters that partition exhaled NO into proximal and peripheral contributions at baseline, postexercise challenge, and postbronchodilator administration in steroid-naive mild-intermittent asthmatic subjects with EIB (24-43 yr old, n = 9) and healthy controls (20-31 yr old, n = 9). The mean +/- SD maximum airway wall flux and airway diffusing capacity were elevated and forced expiratory flow, midexpiratory phase (FEF(25-75)), forced expiratory volume in 1 s (FEV(1)), and FEV(1)/forced vital capacity (FVC) were reduced at baseline in subjects with EIB compared with healthy controls, whereas the steady-state alveolar concentration of NO and FVC were not different. Compared with the response of healthy controls, exercise challenge significantly reduced FEV(1) (-23 +/- 15%), FEF(25-75) (-37 +/- 18%), FVC (-12 +/- 12%), FEV(1)/FVC (-13 +/- 8%), and maximum airway wall flux (-35 +/- 11%) relative to baseline in subjects with EIB, whereas bronchodilator administration only increased FEV(1) (+20 +/- 21%), FEF(25-75) (+56 +/- 41%), and FEV(1)/FVC (+13 +/- 9%). We conclude that mild-intermittent steroid-naive asthmatic subjects with EIB have altered airway NO exchange dynamics at baseline and after exercise challenge but that these changes occur by distinct mechanisms and are not correlated with alterations in spirometry.

Pulmonary rehabilitation in lymphangioleiomyomatosis: a controlled clinical trial.

PubMed

Araujo, Mariana S; Baldi, Bruno G; Freitas, Carolina S G; Albuquerque, André L P; Marques da Silva, Cibele C B; Kairalla, Ronaldo A; Carvalho, Celso R F; Carvalho, Carlos R R

2016-05-01

Lymphangioleiomyomatosis (LAM) is a cystic lung disease frequently associated with reduced exercise capacity. The aim of this study was to assess safety and efficacy of pulmonary rehabilitation in LAM.This controlled clinical trial included 40 patients with LAM and a low physical activity level. The pulmonary rehabilitation programme comprised 24 aerobic and muscle strength training sessions and education. The primary outcome was exercise capacity (endurance time during a constant work rate exercise test). Secondary outcomes included health-related quality of life (St George's Respiratory Questionnaire (SGRQ)), 6-min walking distance (6MWD), dyspnoea, peak oxygen consumption (V'O2 ), daily physical activity (pedometer), symptoms of anxiety and depression, lung function and peripheral muscle strength (one-repetition maximum).The baseline characteristics were well balanced between the groups. The pulmonary rehabilitation group exhibited improvements in the following outcomes versus controls: endurance time (median (interquartile range) 169 (2-303) s versus -33 (-129-39) s; p=0.001), SGRQ (median (interquartile range) -8 (-16-2) versus 2 (-4-5); p=0.002) and 6MWD (median (interquartile range) 59 (13-81) m versus 20 (-12-30) m; p=0.002). Dyspnoea, peak V'O2 , daily physical activity and muscle strength also improved significantly. No serious adverse events were observed.Pulmonary rehabilitation is a safe intervention and improves exercise capacity, dyspnoea, daily physical activity, quality of life and muscle strength in LAM. Copyright ©ERS 2016.

Prolonged head-down tilt exposure reduces maximal cutaneous vasodilator and sweating capacity in humans

NASA Technical Reports Server (NTRS)

Crandall, C. G.; Shibasaki, M.; Wilson, T. E.; Cui, J.; Levine, B. D.

2003-01-01

Cutaneous vasodilation and sweat rate are reduced during a thermal challenge after simulated and actual microgravity exposure. The effects of microgravity exposure on cutaneous vasodilator capacity and on sweat gland function are unknown. The purpose of this study was to test the hypothesis that simulated microgravity exposure, using the 6 degrees head-down tilt (HDT) bed rest model, reduces maximal forearm cutaneous vascular conductance (FVC) and sweat gland function and that exercise during HDT preserves these responses. To test these hypotheses, 20 subjects were exposed to 14 days of strict HDT bed rest. Twelve of those subjects exercised (supine cycle ergometry) at 75% of pre-bed rest heart rate maximum for 90 min/day throughout HDT bed rest. Before and after HDT bed rest, maximal FVC was measured, via plethysmography, by heating the entire forearm to 42 degrees C for 45 min. Sweat gland function was assessed by administering 1 x 10(-6) to 2 M acetylcholine (9 doses) via intradermal microdialysis while simultaneously monitoring sweat rate over the microdialysis membranes. In the nonexercise group, maximal FVC and maximal stimulated sweat rate were significantly reduced after HDT bed rest. In contrast, these responses were unchanged in the exercise group. These data suggest that 14 days of simulated microgravity exposure, using the HDT bed rest model, reduces cutaneous vasodilator and sweating capacity, whereas aerobic exercise training during HDT bed rest preserves these responses.

Improving the Accuracy of Predicting Maximal Oxygen Consumption (VO2pk)

NASA Technical Reports Server (NTRS)

Downs, Meghan E.; Lee, Stuart M. C.; Ploutz-Snyder, Lori; Feiveson, Alan

2016-01-01

Maximal oxygen (VO2pk) is the maximum amount of oxygen that the body can use during intense exercise and is used for benchmarking endurance exercise capacity. The most accurate method to determineVO2pk requires continuous measurements of ventilation and gas exchange during an exercise test to maximal effort, which necessitates expensive equipment, a trained staff, and time to set-up the equipment. For astronauts, accurate VO2pk measures are important to assess mission critical task performance capabilities and to prescribe exercise intensities to optimize performance. Currently, astronauts perform submaximal exercise tests during flight to predict VO2pk; however, while submaximal VO2pk prediction equations provide reliable estimates of mean VO2pk for populations, they can be unacceptably inaccurate for a given individual. The error in current predictions and logistical limitations of measuring VO2pk, particularly during spaceflight, highlights the need for improved estimation methods.

Arm blood flow and metabolism during arm and combined arm and leg exercise in humans

PubMed Central

Volianitis, S; Secher, N H

2002-01-01

The cardiovascular response to exercise with several groups of skeletal muscle suggests that work with the arms may decrease leg blood flow. This study evaluated whether intense exercise with the legs would have a similar effect on arm blood flow (Q̇arm) and O2 consumption (V̇O2,arm). Ten healthy male subjects (age 21 ± 1 year; mean ± S.D.) performed arm cranking at 80 % of maximum arm work capacity (A trial) and combined arm cranking with cycling at 60 % of maximum leg work capacity (A + L trial). The combined trial was a maximum effort for 5-6 min. Q̇arm measurement by thermodilution in the axilliary vein and arterial and venous blood samples permitted calculation of V̇O2,arm. During the combined trial, Q̇arm was reduced by 0.58 ± 0.25 l min−1 (19.1 ± 3.0 %, P < 0.05) from the value during arm cranking (3.00 ± 0.46 l min−1). The arterio-venous O2 difference increased from 122 ± 15 ml l−1 during the arm trial to 150 ± 21 ml l−1 (P < 0.05) during the combined trial. Thus, V̇O2,arm (0.45 ± 0.06 l min−1) was reduced by 9.6 ± 6.3 % (P < 0.05) and arm vascular conductance from 27 ± 4 to 23 ± 3 ml min−1 (mmHg)−1 (P < 0.05) as noradrenaline spillover from the arm increased from 7.5 ± 3.5 to 13.8 ± 4.2 nmol min−1 (P < 0.05). The data suggest that during maximal whole body exercise in humans, arm vasoconstriction is established to an extent that affects oxygen delivery to and utilisation by working skeletal muscles. PMID:12411540

Effects of Twice-Weekly Intense Aerobic Exercise in Early Subacute Stroke: A Randomized Controlled Trial.

PubMed

Sandberg, Klas; Kleist, Marie; Falk, Lars; Enthoven, Paul

2016-08-01

To examine the effects of 12 weeks of twice-weekly intensive aerobic exercise on physical function and quality of life after subacute stroke. Randomized controlled trial. Ambulatory care. Patients (N=56; 28 women) aged ≥50 years who had a mild stroke (98% ischemic) and were discharged to independent living and enrolled 20 days (median) after stroke onset. Sixty minutes of group aerobic exercise, including 2 sets of 8 minutes of exercise with intensity up to exertion level 14 or 15 of 20 on the Borg rating of perceived exertion scale, twice weekly for 12 weeks (n=29). The nonintervention group (n=27) received no organized rehabilitation or scheduled physical exercise. Primary outcome measures included aerobic capacity on the standard ergometer exercise stress test (peak work rate) and walking distance on the 6-minute walk test (6MWT). Secondary outcome measures included maximum walking speed for 10m, balance on the timed Up and Go (TUG) test and single leg stance (SLS), health-related quality of life on the European Quality of Life Scale (EQ-5D), and participation and recovery after stroke on the Stroke Impact Scale (SIS) version 2.0 domains 8 and 9. Participants were evaluated pre- and postintervention. Patient-reported measures were also evaluated at 6-month follow-up. The following improved significantly more in the intervention group (pre- to postintervention): peak work rate (group × time interaction, P=.006), 6MWT (P=.011), maximum walking speed for 10m (P<.001), TUG test (P<.001), SLS right and left (eyes open) (P<.001 and P=.022, respectively), and SLS right (eyes closed) (P=.019). Aerobic exercise was associated with improved EQ-5D scores (visual analog scale, P=.008) and perceived recovery (SIS domain 9, P=.002). These patient-reported improvements persisted at 6-month follow-up. Intensive aerobic exercise twice weekly early in subacute mild stroke improved aerobic capacity, walking, balance, health-related quality of life, and patient-reported recovery. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Hemodynamic responses to small muscle mass exercise in heart failure patients with reduced ejection fraction

PubMed Central

Barrett-O'Keefe, Zachary; Lee, Joshua F.; Berbert, Amanda; Witman, Melissa A. H.; Nativi-Nicolau, Jose; Stehlik, Josef; Richardson, Russell S.

2014-01-01

To better understand the mechanisms responsible for exercise intolerance in heart failure with reduced ejection fraction (HFrEF), the present study sought to evaluate the hemodynamic responses to small muscle mass exercise in this cohort. In 25 HFrEF patients (64 ± 2 yr) and 17 healthy, age-matched control subjects (64 ± 2 yr), mean arterial pressure (MAP), cardiac output (CO), and limb blood flow were examined during graded static-intermittent handgrip (HG) and dynamic single-leg knee-extensor (KE) exercise. During HG exercise, MAP increased similarly between groups. CO increased significantly (+1.3 ± 0.3 l/min) in the control group, but it remained unchanged across workloads in HFrEF patients. At 15% maximum voluntary contraction (MVC), forearm blood flow was similar between groups, while HFrEF patients exhibited an attenuated increase at the two highest intensities compared with controls, with the greatest difference at the highest workload (352 ± 22 vs. 492 ± 48 ml/min, HFrEF vs. control, 45% MVC). During KE exercise, MAP and CO increased similarly across work rates between groups. However, HFrEF patients exhibited a diminished leg hyperemic response across all work rates, with the most substantial decrement at the highest intensity (1,842 ± 64 vs. 2,675 ± 81 ml/min; HFrEF vs. control, 15 W). Together, these findings indicate a marked attenuation in exercising limb perfusion attributable to impairments in peripheral vasodilatory capacity during both arm and leg exercise in patients with HFrEF, which likely plays a role in limiting exercise capacity in this patient population. PMID:25260608

Cardiorespiratory functional assessment after pediatric heart transplantation.

PubMed

Pastore, E; Turchetta, A; Attias, L; Calzolari, A; Giordano, U; Squitieri, C; Parisi, F

2001-12-01

Limited data are available on the exercise capacity of young heart transplant recipients. The aim of this study was therefore to assess cardiorespiratory responses to exercise in this group of patients. Fourteen consecutive heart transplant recipients (six girls and eight boys, age-range 5-15 yr) and 14 healthy matched controls underwent a Bruce treadmill test to determine: duration of test; resting and maximum heart rates; maximum systolic blood pressure; peak oxygen consumption (VO2 peak); and cardiac output. Duration of test and heart rate increase were then compared with: time since transplantation, rejections per year, and immunosuppressive drugs received. The recipients also underwent the following lung function tests: forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1). When compared with healthy controls, transplant recipients had tachycardia at rest (126 +/- 3.7 beats/min; p < 0.001); significantly reduced tolerance (9.3 +/- 0.4 min; p < 0.001), a maximum heart rate of 169 +/- 5.4 beats/min (p < 0.05); a cardiac output of 5.65 +/- 0.6 L/min (p < 0.05); and a lower heart-rate increase from rest to peak exercise (p < 0.001) but a similar VO2 peak. The heart-rate increase correlated significantly with time post-transplant (r = 0.55; p < 0.05), number of rejection episodes per year (r = - 0.63; p < 0.05), and number of immunosuppressive drugs (r = - 0.60; p < 0.05). The recipients had normal FVC and FEV1 values. After surgery, few heart transplant recipients undertake physical activity, possibly owing to over-protective parents and teachers and to a lack of suitable supervised facilities. The authors stress the importance of a cardiorespiratory functional evaluation for assessment of health status and to encourage recipients, if possible, to undertake regular physical activity.

Physiological effects of hydrogen sulfide inhalation during exercise in healthy men.

PubMed

Bhambhani, Y; Singh, M

1991-11-01

Occupational exposure to hydrogen sulfide (H2S) is prevalent in a variety of industries. H2S when inhaled 1) is oxidized into a sulfate or a thiosulfate by oxygen bound to hemoglobin and 2) suppresses aerobic metabolism by inhibiting cytochrome oxidase (c and aa3) activity in the electron transport chain. The purpose of this study was to examine the acute effects of oral inhalation of H2S on the physiological responses during graded cycle exercise performed to exhaustion in healthy male subjects. Sixteen volunteers were randomly exposed to 0 (control), 0.5, 2.0, and 5.0 ppm H2S on four separate occasions. Compared with the control values, the results indicated that the heart rate and expired ventilation were unaffected as a result of the H2S exposures during submaximal and maximal exercise. The oxygen uptake had a tendency to increase, whereas carbon dioxide output had a tendency to decrease as a result of the H2S exposures, but only the 5.0 ppm exposure resulted in a significantly higher maximum oxygen uptake. Blood lactate concentrations increased significantly during submaximal and maximal exercise as a result of the 5.0 ppm exposure. Despite these large increases in lactate concentration, the maximal power output of the subjects was not significantly altered as a result of the 5.0 ppm H2S exposure. It was concluded that healthy young male subjects could safely exercise at their maximum metabolic rates while breathing 5.0 ppm H2S without experiencing a significant reduction in their maximum physical work capacity during short-term incremental exercise.

Effect of nifedipine on choroidal blood flow regulation during isometric exercise.

PubMed

Schmidl, Doreen; Prinz, Ana; Kolodjaschna, Julia; Polska, Elzbieta; Luksch, Alexandra; Fuchsjager-Mayrl, Gabriele; Garhofer, Gerhard; Schmetterer, Leopold

2012-01-25

To determine whether nifedipine, an L-type calcium channel blocker, alters choroidal blood flow (ChBF) regulation during isometric exercise in healthy subjects. The study was carried out in a randomized, placebo-controlled, double-masked, two-way crossover design. Fifteen healthy male subjects were randomly assigned to receive either placebo or nifedipine on two different study days. Subfoveal ChBF was measured with laser Doppler flowmetry while the study participants performed isometric exercise (squatting). This was performed before drug administration and during infusion of nifedipine and placebo, respectively. Mean arterial pressure (MAP) and intraocular pressure (IOP) were measured noninvasively, and ocular perfusion pressure (OPP) was calculated as ⅔ MAP-IOP. MAP and OPP increased significantly during all squatting periods (P < 0.01). The increase in ChBF was less pronounced than the increase in OPP during isometric exercise. Nifedipine did not alter the OPP increase in response to isometric exercise, but it significantly augmented the exercise-induced increase in ChBF (P < 0.001 vs. placebo). Although ChBF increased by a maximum of 14.2% ± 9.2% during the squatting period when placebo was administered, the maximum increase during administration of nifedipine was 23.2% ± 7.2%. In conclusion, the data of the present study suggest that nifedipine augments the ChBF response to an experimental increase in OPP. In addition, it confirms that the choroidal vasculature has a significant regulatory capacity over wide ranges of OPPs during isometric exercise. (ClinicalTrials.gov number, NCT00280462.).

Reduced Exercise Tolerance and Pulmonary Capillary Recruitment with Remote Secondhand Smoke Exposure

PubMed Central

Arjomandi, Mehrdad; Haight, Thaddeus; Sadeghi, Nasrat; Redberg, Rita; Gold, Warren M.

2012-01-01

Rationale Flight attendants who worked on commercial aircraft before the smoking ban in flights (pre-ban FAs) were exposed to high levels of secondhand smoke (SHS). We previously showed never-smoking pre-ban FAs to have reduced diffusing capacity (Dco) at rest. Methods To determine whether pre-ban FAs increase their Dco and pulmonary blood flow () during exercise, we administered a symptom-limited supine-posture progressively increasing cycle exercise test to determine the maximum work (watts) and oxygen uptake () achieved by FAs. After 30 min rest, we then measured Dco and at 20, 40, 60, and 80 percent of maximum observed work. Results The FAs with abnormal resting Dco achieved a lower level of maximum predicted work and compared to those with normal resting Dco (mean±SEM; 88.7±2.9 vs. 102.5±3.1%predicted ; p = 0.001). Exercise limitation was associated with the FAs' FEV1 (r = 0.33; p = 0.003). The Dco increased less with exercise in those with abnormal resting Dco (mean±SEM: 1.36±0.16 vs. 1.90±0.16 ml/min/mmHg per 20% increase in predicted watts; p = 0.020), and amongst all FAs, the increase with exercise seemed to be incrementally lower in those with lower resting Dco. Exercise-induced increase in was not different in the two groups. However, the FAs with abnormal resting Dco had less augmentation of their Dco with increase in during exercise (mean±SEM: 0.93±0.06 vs. 1.47±0.09 ml/min/mmHg per L/min; p<0.0001). The Dco during exercise was inversely associated with years of exposure to SHS in those FAs with ≥10 years of pre-ban experience (r = −0.32; p = 0.032). Conclusions This cohort of never-smoking FAs with SHS exposure showed exercise limitation based on their resting Dco. Those with lower resting Dco had reduced pulmonary capillary recruitment. Exposure to SHS in the aircraft cabin seemed to be a predictor for lower Dco during exercise. PMID:22493689

Effects of solar radiation on endurance exercise capacity in a hot environment.

PubMed

Otani, Hidenori; Kaya, Mitsuharu; Tamaki, Akira; Watson, Phillip; Maughan, Ronald J

2016-04-01

The present study investigated the effects of variations in solar radiation on endurance exercise capacity and thermoregulatory responses in a hot environment. Eight male volunteers performed four cycle exercise trials at 70 % maximum oxygen uptake until exhaustion in an environmental chamber maintained at 30 °C and 50 % relative humidity. Volunteers were tested under four solar radiation conditions: 800, 500, 250 and 0 W/m(2). Exercise time to exhaustion was less on the 800 W/m(2) trial (23 ± 4 min) than on all the other trials (500 W/m(2) 30 ± 7 min; P < 0.05, 250 W/m(2) 43 ± 10 min; P < 0.001, 0 W/m(2) 46 ± 10 min; P < 0.001), and on the 500 W/m(2) trial than the 250 W/m(2) (P < 0.05) and 0 W/m(2) (P < 0.01) trials. There were no differences in core (rectal) temperature, total sweat loss, heart rate, skin blood flow, cutaneous vascular conductance and percentage changes in plasma volume between trials (P > 0.05). Mean skin temperature was higher on the 800 W/m(2) trial than the 250 and 0 W/m(2) trials (P < 0.05), and on the 500 W/m(2) trial than the 0 W/m(2) trial (P < 0.05). The core-to-skin temperature gradient was narrower on the 800 W/m(2) trial than the 250 and 0 W/m(2) trials (P < 0.05). The present study demonstrates that endurance exercise capacity in a hot environment falls progressively as solar radiation increases.

Current ISS Exercise Countermeasures: Where are we now?

NASA Technical Reports Server (NTRS)

Hayes, J. C.; Loerch, L.; Davis-Street, J.; Haralson, Cortni; Sams, C.

2006-01-01

Current International Space Station (ISS) crew schedules include 1.5 h/d for completion of resistive exercise and 1 h/d of aerobic exercise , 6 d/wk. While ISS post flight decrements in muscle strength, bone m ineral density, and aerobic capacity improved in some crewmembers, de conditioning was still evident even with this volume of exercise. Res ults from early ISS expeditions show maximum loss in bone mineral density of the lumbar spine and pelvis in excess of 1.5% per month, with all crewmembers demonstrating significant bone loss in one or more re gions. Similarly, post flight muscle strength losses in the hamstring and quadriceps muscle groups exceeded 30% in the immediate post miss ion period in some crewmembers. Measures of aerobic capacity early in the mission show average decrements of 15%, but with onboard aerobic exercise capability, the crew has been able to "train up" over the co urse of the mission. These findings are highly variable among crewmem bers and appear to be correlated with availability and reliability of the inflight resistive exercise device (RED), cycle ergometer, and t readmill. This suite of hardware was installed on ISS with limited op erational evaluation in groundbased test beds. As a result, onorbit hardware constraints have resulted in inadequate physical stimulus, d econditioning, and increased risk for compromised performance during intra and extravehicular activities. These issues indicate that the c urrent ISS Countermeasures System reliability or validity are not ade quate for extendedduration exploration missions. Learning Objective: A better understanding of the status of ISS exercise countermeasures , their ability to protect physiologic systems, and recommendations for exploration exercise countermeasures.

Morphological and physiological studies on Indian national kabaddi players.

PubMed Central

Dey, S K; Khanna, G L; Batra, M

1993-01-01

Twenty-five national kabaddi players (Asiad gold medalists 1990), mean age 27.91 years, who attended a national camp at the Sports Authority of India, Bangalore before the Beijing Asian Games in 1990, were investigated for their physical characteristics, body fat, lean body mass (LBM) and somatotype. The physiological characteristics assessed included back strength, maximum oxygen uptake capacity and anaerobic capacity (oxygen debt) and related cardiorespiratory parameters (oxygen pulse, breathing equivalent, maximum pulmonary ventilation, maximum heart rate). Body fat was calculated from skinfold thicknesses taken at four different sites, using Harpenden skinfold calipers. An exercise test (graded protocol) was performed on a bicycle ergometer (ER-900) using a computerized EOS Sprint (Jaeger, West Germany). The mean(s.d.) percentage body fat (17.56(3.48)) of kabaddi players was found to be higher than normal sedentary people. Their physique was found to be endomorphic mesomorph (3.8-5.2-1.7). Mean(s.d.) back strength, maximum oxygen uptake capacity (VO2max) and oxygen debt were found to be 162.6(18.08) kg, 42.6(4.91) ml kg-1 min-1 and 5.02(1.29) litre respectively. Physical characteristics, percentage body fat, somatotype, maximum oxygen uptake capacity and anaerobic capacity (oxygen debt) and other cardiorespiratory parameters were compared with other national counterparts. Present data are comparable with data for judo, wrestling and weightlifting. Since no such study has been conducted on international counterparts, these data could not be compared. These data may act as a guideline in the selection of future kabaddi players and to attain the physiological status comparable to the present gold medalists. Images Figure 4 Figure 5 p242-a PMID:8130960

Exercise Tolerance in Children With Early Onset Scoliosis: Growing Rod Treatment "Graduates".

PubMed

Jeans, Kelly A; Johnston, Charles E; Stevens, Wilshaw R; Tran, Dong-Phuong

2016-11-01

Prospectively enrolled early-onset scoliosis (EOS) patients undergoing growing rod treatment, who have had no surgery for >1 year and/or have received definitive fusion (growing rod "graduates"). To assess oxygen consumption during exercise and determine if a diminished conventional pulmonary function test (PFT) correlates with metabolic, pulmonary, and cardiovascular measures during exercise. Based on clinical impression and sequential PFT values, EOS patients who have undergone extensive treatment are thought to have limited capacity during exercise. The use of PFTs in this population has been a primary outcome measure of respiratory capacity; however, PFTs are dependent on effort, and thus subjective. This led us to find a new assessment of outcome, to better understand their pulmonary capacity. Patients underwent oxygen consumption (VO 2 ) testing while walking at self-selected speed over-ground and during a graded exercise test. Maximal VO 2 was predicted in those who completed the test to 85% of maximal heart rate (HR). Statistical analysis included Mann-Whitney U test and Spearman correlation coefficient (α = 0.05). 12 patients participated. Over-ground walking showed that EOS graduates chose to walk at the same speed, but at a higher VO 2 Cost (0.28 mL/kg/m) than controls (0.22 mL/kg/m; p < .001). Treadmill exercise testing showed 9 of 12 subjects able to complete the 85% of predicted maximum protocol. The EOS group had lower VO 2 during the final stage (27.9 mL/kg/min) compared to controls (34.2 mL/kg/min; p = .021); however, their heart rate reached the same values. Subjects completing the protocol had lower predicted VO 2 max (38.5 mL/kg/min) compared with controls (45.0 mL/kg/min), but this was not significant. Although PFT data suggest clinically relevant pulmonary compromise in EOS patients, the current study shows that these children are able to keep up with their peers in daily activities and also have the capacity to exercise. Level II, therapeutic. Copyright © 2016 Scoliosis Research Society. Published by Elsevier Inc. All rights reserved.

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.

Effects of group exercise on functional abilities: Differences between physically active and physically inactive women.

PubMed

Cokorilo, Nebojsa; Mikalacki, Milena; Satara, Goran; Cvetkovic, Milan; Marinkovic, Dragan; Zvekic-Svorcan, Jelena; Obradovic, Borislav

2018-03-30

Aerobic exercises to music can have a positive effect on functional and motor skills of an exerciser, their health, as well as an aesthetic and socio-psychological component. The objective of this study was to determine the effects of reactive exercising in a group on functional capabilities in physically active and physically inactive women. A prospective study included 64 healthy women aged 40-60 years. The sample was divided into the experimental group (n= 36), i.e. physically active women who have been engaged in recreational group exercises at the Faculty of Sport and Physical Education, University of Novi Sad, Serbia, and the control group (n= 28), which consisted of physically inactive women. All the participants were monitored using the same protocol before and after the implementation of the research. All women had their height, weight, body mass index measured as well as spiroergometric parameters determined according to the Bruce protocol. A univariate analysis of variance has shown that there is a statistically significant difference between the experimental group and the control group in maximum speed, the total duration of the test, relative oxygen consumption, absolute oxygen consumption and ventilation during the final measurement. After the training intervention, the experimental group showed improvements in all the parameters analyzed compared with pretest values. The recreational group exercise model significantly improves aerobic capacity and functioning of the cardiovascular system. Therefore, it is essential for women to be involved more in any form of recreational group exercising in order to improve functional capacity and health.

[Physical activity and blood pressure. An epidemiological brief review of primary preventive effects of physical exercise activities].

PubMed

Marti, B

1992-04-07

The relation between physical exercise and blood pressure as well as the risk of hypertension has been investigated extensively during recent years. Cross-sectional studies on exercising and physically fit subjects have shown that endurance capacity (i. e. maximum aerobic capacity) is inversely related to resting blood pressure. However, not all physical activities are associated with lower blood pressure levels; e.g. swimming, weight lifting and competitive cross-country skiing were found to be related to elevated blood pressure values in some studies. Population-based investigations reveal a trend towards lower blood pressure values in physically habitually active persons, with the difference between active and inactive subjects not exceeding 5 mmHg. Three epidemiological cohort studies have consistently demonstrated that sedentary, unfit persons have a 20 to 50% higher prospective risk of hypertension, as compared to exercising, physically fit persons. Some intervention studies with normotensive subjects show a reduction in resting blood pressure of 5 to 10 mmHg at best after several months of aerobic training, while other studies show no effect. At least two factors could be responsible for these somewhat inconsistent observations: 1. exercise intensity may act as an 'effect modifier', since vigorous to maximally hard exercise rather increases than lowers resting blood pressure, 2. in statistical analysis on the effect of physical training on blood pressure, it is crucial whether concomitant changes in body weight and body composition are taken into account: any adjustment for changes in body composition will substantially reduce the magnitude of 'exercise-induced' reductions in blood pressure.(ABSTRACT TRUNCATED AT 250 WORDS)

Reduced exercise capacity in persons with Down syndrome: cause, effect, and management

PubMed Central

Mendonca, Goncalo V; Pereira, Fernando D; Fernhall, Bo

2010-01-01

Persons with Down syndrome (DS) have reduced peak and submaximal exercise capacity. Because ambulation is one predictor of survival among adults with DS, a review of the current knowledge of the causes, effects, and management of reduced exercise capacity in these individuals would be important. Available data suggest that reduced exercise capacity in persons with DS results from an interaction between low peak oxygen uptake (VO2peak) and poor exercise economy. Of several possible explanations, chronotropic incompetence has been shown to be the primary cause of low VO2peak in DS. In contrast, poor exercise economy is apparently dependent on disturbed gait kinetics and kinematics resulting from joint laxity and muscle hypotonia. Importantly, there is enough evidence to suggest that such low levels of physical fitness (reduced exercise capacity and muscle strength) limit the ability of adults with DS to perform functional tasks of daily living. Consequently, clinical management of reduced exercise capacity in DS seems important to ensure that these individuals remain productive and healthy throughout their lives. However, few prospective studies have examined the effects of structured exercise training in this population. Existent data suggest that exercise training is beneficial for improving exercise capacity and physiological function in persons with DS. This article reviews the current knowledge of the causes, effects, and management of reduced exercise capacity in DS. This review is limited to the acute and chronic responses to submaximal and peak exercise intensities because data on supramaximal exercise capacity of persons with DS have been shown to be unreliable. PMID:21206759

Metformin improves performance in high-intensity exercise, but not anaerobic capacity in healthy male subjects.

PubMed

Learsi, S K; Bastos-Silva, V J; Lima-Silva, A E; Bertuzzi, R; De Araujo, G G

2015-10-01

The aim of this study was to determine the ergogenic effects of metformin in high-intensity exercise, as well as its effects on anaerobic capacity, in healthy and physically active men. Ten subjects (mean (± standard deviation) maximal oxygen uptake (V˙O2max ) 38.6 ± 4.5 mL/kg per min) performed the following tests in a cycle ergometer: (i) an incremental test; (ii) six submaximal constant workload tests at 40%-90% (V˙O2max ); and (iii) two supramaximal tests (110% (V˙O2max ). Metformin (500 mg) or placebo was ingested 60 min before the supramaximal test. There were no significant differences between the placebo and metformin groups in terms of maximum accumulated oxygen deficit (2.8 ± 0.6 vs 3.0 ± 0.8 L, respectively; P = 0.08), lactate concentrations (7.8 ± 2.6 vs 7.5 ± 3.0 mmol/L, respectively; P = 0.75) or O2 consumed in either the last 30 s of exercise (40.4 ± 4.4 vs 39.9 ± 4.0 mL/kg per min, respectively; P = 0.35) or the first 110 s of exercise (29.0 ± 2.5 vs 29.5 ± 3.0 mL/kg per min, respectively; P = 0.42). Time to exhaustion was significantly higher after metformin than placebo ingestion (191 ± 33 vs 167 ± 32 s, respectively; P = 0.001). The fast component of V˙O2 recovery was higher in the metformin than placebo group (12.71 vs 12.18 mL/kg per min, respectively; P = 0.025). Metformin improved performance and anaerobic alactic contribution during high-intensity exercise, but had no effect on overall anaerobic capacity in healthy subjects. © 2015 Wiley Publishing Asia Pty Ltd.

L-Arginine Affects Aerobic Capacity and Muscle Metabolism in MELAS (Mitochondrial Encephalomyopathy, Lactic Acidosis and Stroke-Like Episodes) Syndrome.

PubMed

Rodan, Lance H; Wells, Greg D; Banks, Laura; Thompson, Sara; Schneiderman, Jane E; Tein, Ingrid

2015-01-01

To study the effects of L-arginine (L-Arg) on total body aerobic capacity and muscle metabolism as assessed by (31)Phosphorus Magnetic Resonance Spectroscopy ((31)P-MRS) in patients with MELAS (Mitochondrial Encephalomyopathy with Lactic Acidosis and Stroke-like episodes) syndrome. We performed a case control study in 3 MELAS siblings (m.3243A>G tRNA(leu(UUR)) in MTTL1 gene) with different % blood mutant mtDNA to evaluate total body maximal aerobic capacity (VO(2peak)) using graded cycle ergometry and muscle metabolism using 31P-MRS. We then ran a clinical trial pilot study in MELAS sibs to assess response of these parameters to single dose and a 6-week steady-state trial of oral L-Arginine. At baseline (no L-Arg), MELAS had lower serum Arg (p = 0.001). On 3(1)P-MRS muscle at rest, MELAS subjects had increased phosphocreatine (PCr) (p = 0.05), decreased ATP (p = 0.018), and decreased intracellular Mg(2+) (p = 0.0002) when compared to matched controls. With L-arginine therapy, the following trends were noted in MELAS siblings on cycle ergometry: (1) increase in mean % maximum work at anaerobic threshold (AT) (2) increase in % maximum heart rate at AT (3) small increase in VO(2peak). On (31)P-MRS the following mean trends were noted: (1) A blunted decrease in pH after exercise (less acidosis) (2) increase in Pi/PCr ratio (ADP) suggesting increased work capacity (3) a faster half time of PCr recovery (marker of mitochondrial activity) following 5 minutes of moderate intensity exercise (4) increase in torque. These results suggest an improvement in aerobic capacity and muscle metabolism in MELAS subjects in response to supplementation with L-Arg. Intramyocellular hypomagnesemia is a novel finding that warrants further study. Class III evidence that L-arginine improves aerobic capacity and muscle metabolism in MELAS subjects. ClinicalTrials.gov NCT01603446.

Physiological adaptations to interval training and the role of exercise intensity.

PubMed

MacInnis, Martin J; Gibala, Martin J

2017-05-01

Interval exercise typically involves repeated bouts of relatively intense exercise interspersed by short periods of recovery. A common classification scheme subdivides this method into high-intensity interval training (HIIT; 'near maximal' efforts) and sprint interval training (SIT; 'supramaximal' efforts). Both forms of interval training induce the classic physiological adaptations characteristic of moderate-intensity continuous training (MICT) such as increased aerobic capacity (V̇O2 max ) and mitochondrial content. This brief review considers the role of exercise intensity in mediating physiological adaptations to training, with a focus on the capacity for aerobic energy metabolism. With respect to skeletal muscle adaptations, cellular stress and the resultant metabolic signals for mitochondrial biogenesis depend largely on exercise intensity, with limited work suggesting that increases in mitochondrial content are superior after HIIT compared to MICT, at least when matched-work comparisons are made within the same individual. It is well established that SIT increases mitochondrial content to a similar extent to MICT despite a reduced exercise volume. At the whole-body level, V̇O2 max is generally increased more by HIIT than MICT for a given training volume, whereas SIT and MICT similarly improve V̇O2 max despite differences in training volume. There is less evidence available regarding the role of exercise intensity in mediating changes in skeletal muscle capillary density, maximum stroke volume and cardiac output, and blood volume. Furthermore, the interactions between intensity and duration and frequency have not been thoroughly explored. While interval training is clearly a potent stimulus for physiological remodelling in humans, the integrative response to this type of exercise warrants further attention, especially in comparison to traditional endurance training. © 2016 The Authors. The Journal of Physiology © 2016 The Physiological Society.

Physiological adaptations to interval training and the role of exercise intensity

PubMed Central

MacInnis, Martin J.

2016-01-01

Abstract Interval exercise typically involves repeated bouts of relatively intense exercise interspersed by short periods of recovery. A common classification scheme subdivides this method into high‐intensity interval training (HIIT; ‘near maximal’ efforts) and sprint interval training (SIT; ‘supramaximal’ efforts). Both forms of interval training induce the classic physiological adaptations characteristic of moderate‐intensity continuous training (MICT) such as increased aerobic capacity (V˙O2 max ) and mitochondrial content. This brief review considers the role of exercise intensity in mediating physiological adaptations to training, with a focus on the capacity for aerobic energy metabolism. With respect to skeletal muscle adaptations, cellular stress and the resultant metabolic signals for mitochondrial biogenesis depend largely on exercise intensity, with limited work suggesting that increases in mitochondrial content are superior after HIIT compared to MICT, at least when matched‐work comparisons are made within the same individual. It is well established that SIT increases mitochondrial content to a similar extent to MICT despite a reduced exercise volume. At the whole‐body level, V˙O2 max is generally increased more by HIIT than MICT for a given training volume, whereas SIT and MICT similarly improve V˙O2 max despite differences in training volume. There is less evidence available regarding the role of exercise intensity in mediating changes in skeletal muscle capillary density, maximum stroke volume and cardiac output, and blood volume. Furthermore, the interactions between intensity and duration and frequency have not been thoroughly explored. While interval training is clearly a potent stimulus for physiological remodelling in humans, the integrative response to this type of exercise warrants further attention, especially in comparison to traditional endurance training. PMID:27748956

Physiological models to understand exercise fatigue and the adaptations that predict or enhance athletic performance.

PubMed

Noakes, T D

2000-06-01

A popular concept in the exercise sciences holds that fatigue develops during exercise of moderate to high intensity, when the capacity of the cardiorespiratory system to provide oxygen to the exercising muscles falls behind their demand inducing "anaerobic" metabolism. But this cardiovascular/anaerobic model is unsatisfactory because (i) a more rigorous analysis indicates that the first organ to be affected by anaerobiosis during maximal exercise would likely be the heart, not the skeletal muscles. This probability was fully appreciated by the pioneering exercise physiologists, A. V Hill, A. Bock and D. B. Dill, but has been systematically ignored by modern exercise physiologists; (ii) no study has yet definitely established the presence of either anaerobiosis, hypoxia or ischaemia in skeletal muscle during maximal exercise; (iii) the model is unable to explain why exercise terminates in a variety of conditions including prolonged exercise, exercise in the heat and at altitude, and in those with chronic diseases of the heart and lungs, without any evidence for skeletal muscle anaerobiosis, hypoxia or ischaemia, and before there is full activation of the total skeletal muscle mass, and (iv) cardiovascular and other measures believed to relate to skeletal muscle anaerobiosis, including the maximum oxygen consumption (VO2 max) and the "anaerobic threshold", are indifferent predictors of exercise capacity in athletes with similar abilities. This review considers four additional models that need to be considered when factors limiting either short duration, maximal or prolonged submaximal exercise are evaluated. These additional models are: (i) the energy supply/energy depletion model; (ii) the muscle power/muscle recruitment model; (iii) the biomechanical model and (iv) the psychological model. By reviewing features of these models, this review provides a broad overview of the physiological, metabolic and biomechanical factors that may limit exercise performance under different exercise conditions. A more complete understanding of fatigue during exercise, and the relevance of the adaptations that develop with training, requires that the potential relevance of each model to fatigue under different conditions of exercise must be considered.

Effects of Pressure Support Ventilation May Be Lost at High Exercise Intensities in People with COPD.

PubMed

Anekwe, David; de Marchie, Michel; Spahija, Jadranka

2017-06-01

Pressure support ventilation (PSV) may be used for exercise training in chronic obstructive pulmonary disease (COPD), but its acute effect on maximum exercise capacity is not fully known. The objective of this study was to evaluate the effect of 10 cm H 2 O PSV and a fixed PSV level titrated to patient comfort at rest on maximum exercise workload (WLmax), breathing pattern and metabolic parameters during a symptom-limited incremental bicycle test in individuals with COPD. Eleven individuals with COPD (forced expiratory volume in one second: 49 ± 16%; age: 64 ± 7 years) performed three exercise tests: without a ventilator, with 10 cm H 2 O of PSV and with a fixed level titrated to comfort at rest, using a SERVO-i ventilator. Tests were performed in randomized order and at least 48 hours apart. The WLmax, breathing pattern, metabolic parameters, and mouth pressure (Pmo) were compared using repeated measures analysis of variance. Mean PSV during titration was 8.2 ± 4.5 cm H 2 O. There was no difference in the WLmax achieved during the three tests. At rest, PSV increased the tidal volume, minute ventilation, and mean inspiratory flow with a lower end-tidal CO 2 ; this was not sustained at peak exercise. Pmo decreased progressively (decreased unloading) with PSV at workloads close to peak, suggesting the ventilator was unable to keep up with the increased ventilatory demand at high workloads. In conclusion, with a Servo-i ventilator, 10 cm H 2 O of PSV and a fixed level of PSV established by titration to comfort at rest, is ineffective for the purpose of achieving higher exercise workloads as the acute physiological effects may not be sustained at peak exercise.

Comparing exercise responses to aerobic plus resistance training between postmenopausal breast cancer survivors undergoing aromatase inhibitor therapy and healthy women.

PubMed

Paulo, Thais R S de; Winters-Stone, Kerri M; Viezel, Juliana; Rossi, Fabricio E; Aro, Bruna L; Trindade, Ana Carolina A C; Codogno, Jamile S; Freitas Junior, Ismael F

2018-04-12

The aim of this study was to explore whether postmenopausal breast cancer survivors undergoing aromatase inhibitor therapy differ from healthy postmenopausal women in their response to the same aerobic + resistance training. The participants were separated into two groups: postmenopausal breast cancer survivors undergoing aromatase inhibitor therapy for an average of 20 months (18 women) and healthy postmenopausal women (24 women). We assessed aerobic capacity (predicted maximum oxygen uptake (VO 2 max) and maximum running velocity test (Vmax)) through a walking test, upper and lower body muscle strength using an estimated one-repetition maximum test, and body composition by dual-energy X-ray absorptiometry at baseline and at three, six, and nine months, respectively. The exercise program was performed three times/week over nine months and consisted of 40 min of machine-based strength training (seated cable row, bench press, leg extension, leg press, and leg curl, as well as bridge, abdominal, and standard plank exercises) followed by 30 min of treadmill walking. Analysis of variance (ANOVA) with repeated measures was used to compare the groups over time. Postmenopausal breast cancer survivors undergoing aromatase inhibitor therapy and healthy postmenopausal women presented similar improvements in estimated lower body strength, predicted VO 2max and V max , and body fat mass. For maximal upper body strength, there was a significant group x time interaction after six months of training (p = 0.01). The healthy postmenopausal women presented a significant increase in upper body strength after six months, while postmenopausal breast cancer survivors undergoing aromatase inhibitor therapy demonstrated an improvement only at nine months of training. The breast cancer survivors undergoing aromatase inhibitor therapy presented increased lean mass while healthy postmenopausal women maintained values over time (Breast cancer: 33.7 ± 3.9(Pre) vs. 34.1 ± 3.4 kg (Post) and healthy women: 36.4 ± 5.1 (Pre) vs. 36.4 ± 5.0 kg (Post), p = 0.004). Our findings suggest that postmenopausal women undergoing aromatase inhibitor therapy for breast cancer demonstrated adaptations and similar trainability to the same regimen of resistance + aerobic training as healthy postmenopausal women. Implications for Rehabilitation Combined exercise program (aerobic plus resistance) is an important non-pharmacological strategies to improve strength, aerobic capacity, and body composition in breast cancer survivors undergoing aromatase inhibitor therapy. Furthermore, it is important to highlight that the time of intervention seems to influence the upper body strength response in this population. This study showed that trainers and other specialists do not need to modify the prescription of exercise related to healthy women, since the combined exercise program induced similar benefits in strength, aerobic capacity, and body composition in postmenopausal breast cancer survivors undergoing aromatase inhibitor therapy and healthy postmenopausal women.

The joint impact of smoking and exercise capacity on clinical outcomes among women with suspected myocardial ischemia: the WISE study.

PubMed

Linke, Sarah E; Rutledge, Thomas; Johnson, B Delia; Olson, Marian B; Bittner, Vera; Cornell, Carol E; Shaw, Leslee J; Eteiba, Wafia; Parashar, Susmita; Sheps, David S; Vido, Diane A; Mulukutla, Suresh; Bairey Merz, C Noel

2009-04-01

Although extensive research has been conducted on both smoking and low exercise capacity alone, few studies have examined the joint impact or interaction of these two risk factors. We examined the joint and interactive effects of smoking and self-reported exercise capacity on subsequent clinical events (heart failure, myocardial infarction [MI], stroke, and cardiovascular-related mortality) among women with suspected myocardial ischemia. At baseline (1996-1999), 789 women completed angiographic testing of coronary artery disease (CAD) severity and provided self-report information about their smoking history and exercise capacity as well as demographic and other risk factor data. Incidence of clinical events among the women was tracked for a median of 5.9 years; this analysis was conducted in 2008. In an adjusted survival analysis, women with a positive smoking history and self-reported low exercise capacity had the greatest risk of experiencing a clinical event (HR = 7.7, 95% CI 2.3, 25.5), followed by women with a positive smoking history and self-reported high exercise capacity (HR = 6.9, 95% CI 2.0, 24.6) and those with a negative smoking history and self-reported low exercise capacity (HR = 4.9, 95% CI 1.5, 15.8), relative to women with a negative smoking history and self-reported high exercise capacity. Additional analyses revealed a significant interaction between smoking history and exercise capacity, such that (1) women with a positive smoking history did not experience an additional significantly greater risk due to low exercise capacity, unlike those with a negative smoking history, and (2) all women experienced a significantly greater risk due to a positive smoking history regardless of their exercise capacity. Among women with suspected myocardial ischemia, the combined protective health effects of self-reported high exercise capacity and a negative smoking history remained significant after controlling for preexisting CAD severity and other established risk factors. These findings highlight the importance of studying behavioral risk factors in combination.

Exercise-induced dehydration alters pulmonary function but does not modify airway responsiveness to dry air in athletes with mild asthma

PubMed Central

Romer, L. M.

2017-01-01

Local airway water loss is the main physiological trigger for exercise-induced bronchoconstriction (EIB). Our aim was to investigate the effects of whole body water loss on airway responsiveness and pulmonary function in athletes with mild asthma and/or EIB. Ten recreational athletes with a medical diagnosis of mild asthma and/or EIB completed a randomized, crossover study. Pulmonary function tests, including spirometry, whole body plethysmography, and diffusing capacity of the lung for carbon monoxide (DlCO), were conducted before and after three conditions: 1) 2 h of exercise in the heat with no fluid intake (dehydration), 2) 2 h of exercise with ad libitum fluid intake (control), and 3) a time-matched rest period (rest). Airway responsiveness was assessed 2 h postexercise/rest via eucapnic voluntary hyperpnea (EVH) to dry air. Exercise in the heat with no fluid intake induced a state of mild dehydration, with a body mass loss of 2.3 ± 0.8% (SD). After EVH, airway narrowing was not different between conditions: median (interquartile range) maximum fall in forced expiratory volume in 1 s was 13 (7–15)%, 11 (9–24)%, and 12 (7–20)% in dehydration, control, and rest conditions, respectively. Dehydration caused a significant reduction in forced vital capacity (300 ± 190 ml, P = 0.001) and concomitant increases in residual volume (260 ± 180 ml, P = 0.001) and functional residual capacity (260 ± 250 ml, P = 0.011), with no change in DlCO. Mild exercise-induced dehydration does not exaggerate airway responsiveness to dry air in athletes with mild asthma/EIB but may affect small airway function. NEW & NOTEWORTHY This study is the first to investigate the effect of whole body dehydration on airway responsiveness. Our data suggest that the airway response to dry air hyperpnea in athletes with mild asthma and/or exercise-induced bronchoconstriction is not exacerbated in a state of mild dehydration. On the basis of alterations in lung volumes, however, exercise-induced dehydration appears to compromise small airway function. PMID:28280109

Exercise-induced dehydration alters pulmonary function but does not modify airway responsiveness to dry air in athletes with mild asthma.

PubMed

Simpson, A J; Romer, L M; Kippelen, P

2017-05-01

Local airway water loss is the main physiological trigger for exercise-induced bronchoconstriction (EIB). Our aim was to investigate the effects of whole body water loss on airway responsiveness and pulmonary function in athletes with mild asthma and/or EIB. Ten recreational athletes with a medical diagnosis of mild asthma and/or EIB completed a randomized, crossover study. Pulmonary function tests, including spirometry, whole body plethysmography, and diffusing capacity of the lung for carbon monoxide (Dl CO ), were conducted before and after three conditions: 1 ) 2 h of exercise in the heat with no fluid intake (dehydration), 2 ) 2 h of exercise with ad libitum fluid intake (control), and 3 ) a time-matched rest period (rest). Airway responsiveness was assessed 2 h postexercise/rest via eucapnic voluntary hyperpnea (EVH) to dry air. Exercise in the heat with no fluid intake induced a state of mild dehydration, with a body mass loss of 2.3 ± 0.8% (SD). After EVH, airway narrowing was not different between conditions: median (interquartile range) maximum fall in forced expiratory volume in 1 s was 13 (7-15)%, 11 (9-24)%, and 12 (7-20)% in dehydration, control, and rest conditions, respectively. Dehydration caused a significant reduction in forced vital capacity (300 ± 190 ml, P = 0.001) and concomitant increases in residual volume (260 ± 180 ml, P = 0.001) and functional residual capacity (260 ± 250 ml, P = 0.011), with no change in Dl CO Mild exercise-induced dehydration does not exaggerate airway responsiveness to dry air in athletes with mild asthma/EIB but may affect small airway function. NEW & NOTEWORTHY This study is the first to investigate the effect of whole body dehydration on airway responsiveness. Our data suggest that the airway response to dry air hyperpnea in athletes with mild asthma and/or exercise-induced bronchoconstriction is not exacerbated in a state of mild dehydration. On the basis of alterations in lung volumes, however, exercise-induced dehydration appears to compromise small airway function. Copyright © 2017 the American Physiological Society.

Cardiorespiratory Considerations in Dance: From Classes to Performances.

PubMed

Rodrigues-Krause, Josianne; Krause, Mauricio; Reischak-Oliveira, Álvaro

2015-09-01

When attempting to ascertain dancers' fitness levels, essential parameters, such as aerobic and anaerobic capacity, muscular power and strength, flexibility, and body composition, must be considered. Dance is characterized as an intermittent type of exercise, demanding energy from different metabolic pathways (aerobic and anaerobic, lactic or alactic). A dancer's maximum aerobic capacity (ranging from 37 to 57 ml·kg(-1)·min(-1)) is related to his or her dance style, gender, level of technical ability, and status in a dance company. However, dancers' cardiorespiratory requirements during dance classes (essentially designed for the development of technical skills) are significantly lower than during dance performances, indicating that there is a divergence between dance training and performance with regard to demands on dancers' physical fitness. It follows that supplementary fitness training is needed in order to optimize dancers' technical and artistic performance and to reduce the incidence of injury. Traditional aerobic and strength training have been proposed to cover dancers' lack of conditioning; however, it seems likely that high-intensity interval training would more properly meet the requirements of today's choreography. Therefore, with an approach that applies basic exercise physiology to dance characteristics, this review covers the following topics: 1. dance as physical exercise; 2. dancers' aerobic capacity; 3. cardiorespiratory demands of dance classes and performances; 4. supplementary fitness training for dancers; and 5. fitness testing and assessment for dancers.

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.

Best Protocol for the Sit-to-Stand Test in Subjects With COPD.

PubMed

Morita, Andrea A; Bisca, Gianna W; Machado, Felipe V C; Hernandes, Nidia A; Pitta, Fabio; Probst, Vanessa S

2018-05-22

Different protocols for the sit-to-stand test (STS) are available for assessing functional capacity in COPD. We sought to correlate each protocol of the STS (ie, the 5-repetition [5-rep STS], the 30-s STS, and the 1-min STS) with clinical outcomes in subjects with COPD. We also aimed to compare the 3 protocols of the STS, to verify their association and agreement, and to verify whether the 3 protocols are able to predict functional exercise capacity and physical activity in daily life (PADL). 23 subjects with COPD (11 men; FEV 1 53 ± 15% predicted) performed 3 protocols of the STS. Subjects also underwent the following assessments: incremental shuttle walking test, 6-min walk test (6MWT), 4-m gait speed test (4MGS), 1-repetition maximum of quadriceps muscle, assessment of PADL, and questionnaires on health-related quality of life and functional status. The 1-min STS showed significant correlations with the 6MWT (r = 0.40), 4MGS (r = 0.64), and PADL (0.40 ≤ r ≤ 0.52), and the 5-rep STS and 30-s STS were associated with the 4MGS (r = 0.54 and r = 0.52, respectively). The speed differed for each protocol (5-rep STS 0.53 ± 0.16 rep/s, 30-s STS 0.48 ± 0.13 rep/s, 1-min STS 0.45 ± 0.11 rep/s, P = .01). However, they presented good agreement (intraclass correlation coefficient ≥ 0.73 for all) and correlated well with each other (r ≥ 0.68 for all). More marked changes in peripheral oxygen saturation ( P = .004), heart rate ( P < .001), blood pressure ( P < .001), dyspnea ( P < .001), and leg fatigue ( P < .001) were found after the 1-min STS protocol. Furthermore, the 3 protocols were equally able to identify subjects with low exercise capacity or preserved exercise capacity. The 1-min STS generated higher hemodynamic demands and correlated better with clinical outcomes in subjects with COPD. Despite the difference in speed performance and physiological demands between the 5-rep STS and 1-min STS, there was a good level of agreement among the 3 protocols. In addition, all 3 tests were able to identify subjects with low exercise capacity or preserved exercise capacity. Copyright © 2018 by Daedalus Enterprises.

14 CFR 385.8 - Exercise of authority in “acting” capacity.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Exercise of authority in âactingâ capacity... Provisions § 385.8 Exercise of authority in “acting” capacity. Unless the assignment provides otherwise, staff members serving in an “acting” capacity may exercise the authority assigned to the staff members...

14 CFR 385.8 - Exercise of authority in “acting” capacity.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false Exercise of authority in âactingâ capacity... Provisions § 385.8 Exercise of authority in “acting” capacity. Unless the assignment provides otherwise, staff members serving in an “acting” capacity may exercise the authority assigned to the staff members...

14 CFR 385.8 - Exercise of authority in “acting” capacity.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Exercise of authority in âactingâ capacity... Provisions § 385.8 Exercise of authority in “acting” capacity. Unless the assignment provides otherwise, staff members serving in an “acting” capacity may exercise the authority assigned to the staff members...

14 CFR 385.8 - Exercise of authority in “acting” capacity.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Exercise of authority in âactingâ capacity... Provisions § 385.8 Exercise of authority in “acting” capacity. Unless the assignment provides otherwise, staff members serving in an “acting” capacity may exercise the authority assigned to the staff members...

14 CFR 385.8 - Exercise of authority in “acting” capacity.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Exercise of authority in âactingâ capacity... Provisions § 385.8 Exercise of authority in “acting” capacity. Unless the assignment provides otherwise, staff members serving in an “acting” capacity may exercise the authority assigned to the staff members...

Orbital Fitness: An Overview of Space Shuttle Cardiopulmonary Exercise Physiology Findings

NASA Technical Reports Server (NTRS)

Moore, Alan D.

2011-01-01

Limited observations regarding the cardiopulmonary responses to aerobic exercise had been conducted during short-duration spaceflight before the Space Shuttle program. This presentation focuses on the findings regarding changes observed in the cardiopulmonary exercise responses during and following Shuttle flights. During flight, maximum oxygen uptake (VO2max) remained unchanged as did the maximum work rate achievable during cycle exercise testing conducted during the last full flight day. Immediately following flight, the ubiquitous finding, confirmed by investigations conducted during the Spacelab Life Sciences missions 1 and 2 and by NASA Detailed Supplemental Objective studies, indicated that VO2max was reduced; however, the reduction in VO2max was transient and returned to preflight levels within 7 days following return. Studies regarding the influence of aerobic exercise countermeasures performed during flight on postflight performance were mostly limited to the examination of the heart rate (HR) response to submaximal exercise testing on landing day. These studies revealed that exercise HR was elevated in individuals who performed little to no exercise during their missions as compared to individuals who performed regular exercise. In addition, astronauts who performed little to no aerobic exercise during flight demonstrated an increased HR and lowered pulse pressure response to the standard stand test on landing day, indicating a decrease in orthostatic function in these individuals. With regard to exercise modality, four devices were examined during the Shuttle era: two treadmills, a cycle ergometer, and a rowing device. Although there were limited investigations regarding the use of these devices for exercise training aboard the Shuttle, there was no clear consensus reached regarding which proved to be a "superior" device. Each device had a unique operational or physiologic limitation associated with its use. In conclusion, exercise research conducted during the Shuttle Program demonstrated that attenuation of postflight deconditioning was possible through use of exercise countermeasures and the Shuttle served as a test bed for equipment destined for use on the International Space Station. Learning Objective: Overview of the Space Shuttle Program research results related to aerobic capacity and performance, including what was learned from research and effectiveness of exercise countermeasures.

Fatigue-induced change in corticospinal drive to back muscles in elite rowers.

PubMed

Fulton, Rick C; Strutton, Paul H; McGregor, Alison H; Davey, Nick J

2002-09-01

This study examined post-exercise changes in corticospinal excitability in five 'elite' rowers and six nonrowers. Transcranial magnetic stimulation (TMS) was delivered to the motor cortex and bilateral electromyographic (EMG) recordings were made from erector spinae (ES) muscles at L3/L4 spinal level and from the first dorsal interosseous (FDI) muscle of the dominant hand. Each subject completed two exercise protocols on a rowing ergometer: a light exercise protocol at a sub-maximal output for 10 min and an intense exercise protocol at maximum output for 1 min. A trial of ten magnetic stimuli was delivered before each of the protocols and, on finishing exercise, further trials of ten stimuli were delivered every 2 min for a 16 min period. Amplitudes of motor-evoked potentials (MEPs) in each of the three test muscles were measured before exercise and during the recovery period after exercise. The non-rowers showed a brief facilitation of MEPs in ES 2 min after light and intense exercise that was only present in the elite rowers after intense exercise. In the period 4-16 min after light exercise, the mean (+/- S.E.M.) MEP amplitude (relative to pre-exercise levels) was less depressed in the elite rowers (79.4 +/- 2.1%) than in the non-rowers (60.9 +/- 2.5%) in the left ES but not significantly so in the right ES. MEP amplitudes in FDI were significantly larger in the elite rowers, averaging 119.0 +/- 3.1% pre-exercise levels, compared with 101.2 +/- 5.8% in the non-rowers. Pre-exercise MEP latencies were no different in the two groups. After light exercise MEP latencies became longer in the elite rowers (left ES, 16.1 +/- 0.5 ms; right ES, 16.1 +/- 0.4 ms; dominant FDI, 23.4 +/- 0.2 ms) than in the non-rowers (left ES, 15.0 +/- 0.3 ms; right ES, 15.2 +/- 0.3 ms; dominant FDI, 21.5 +/- 0.2 ms). There were no differences in MEP depression or latency between elite rowers and non-rowers after intense exercise. We conclude that the smaller degree of MEP depression in the elite rowers after light exercise reflects less central fatigue within corticospinal control pathways than that seen in the non-rowers. The longer latency of MEPs seen in the elite rowers may reflect recruitment of more slower-conducting fatigue-resistant motor units compared with the non-rowers. These differences may be because the energy requirements for the non-rowers during light exercise are closer to their maximum capacity, leading to more fatigue. This notion is supported by the lack of any difference between groups following intense exercise when both groups were working at their own maximum.

Brief report: effect of ambrisentan treatment on exercise-induced pulmonary hypertension in systemic sclerosis: a prospective single-center, open-label pilot study.

PubMed

Saggar, Rajeev; Khanna, D; Shapiro, S; Furst, D E; Maranian, P; Clements, P; Abtin, F; Dua, Shiv; Belperio, J; Saggar, Rajan

2012-12-01

Exercise-induced pulmonary hypertension (ePH) may represent an early, clinically relevant phase in the spectrum of pulmonary vascular disease. The purpose of this pilot study was to describe the changes in hemodynamics and exercise capacity in patients with systemic sclerosis (SSc) spectrum-associated ePH treated with open-label daily ambrisentan. Patients were treated with ambrisentan, 5 mg or 10 mg once daily, for 24 weeks. At baseline and 24 weeks, patients with SSc spectrum disorders exercised in a supine position, on a lower extremity cycle ergometer. All patients had normal hemodynamics at rest. We defined baseline ePH as a mean pulmonary artery pressure of >30 mm Hg with maximum exercise and a transpulmonary gradient (TPG) of >15 mm Hg. The primary end point was change in pulmonary vascular resistance (PVR) with exercise. Secondary end points included an improvement from baseline in 6-minute walking distance, health-related quality of life assessments, and cardiopulmonary hemodynamics. Of the 12 enrolled patients, 11 completed the study. At 24 weeks there were improvements in mean exercise PVR (85.8 dynes × second/cm(5) ; P = 0.003) and mean distance covered during 6-minute walk (44.5 meters; P = 0.0007). Improvements were also observed in mean exercise cardiac output (1.4 liters/minute; P = 0.006), mean pulmonary artery pressure (-4.1 mm Hg; P = 0.02), and total pulmonary resistance (-93.0 dynes × seconds/cm(5) ; P = 0.0008). Three patients developed resting pulmonary arterial hypertension during the 24 weeks. Exercise hemodynamics and exercise capacity in patients with SSc spectrum-associated ePH improved over 24 weeks with exposure to ambrisentan. Placebo-controlled studies are needed to confirm whether this is a drug-related effect and to determine optimal therapeutic regimens for patients with ePH. Copyright © 2012 by the American College of Rheumatology.

Can endurance training improve physical capacity and quality of life in young Fontan patients?

PubMed

Hedlund, Eva R; Lundell, Bo; Söderström, Liselott; Sjöberg, Gunnar

2018-03-01

Children after Fontan palliation have reduced exercise capacity and quality of life. Our aim was to study whether endurance training could improve physical capacity and quality of life in Fontan patients. Fontan patients (n=30) and healthy age- and gender-matched control subjects (n=25) performed a 6-minute walk test at submaximal capacity and a maximal cycle ergometer test. Quality of life was assessed with Pediatric Quality of Life Inventory Version 4.0 questionnaires for children and parents. All tests were repeated after a 12-week endurance training programme and after 1 year. Patients had decreased submaximal and maximal exercise capacity (maximal oxygen uptake 35.0±5.1 ml/minute per·kg versus 43.7±8.4 ml/minute·per·kg, p<0.001) and reported a lower quality of life score (70.9±9.9 versus 85.7±8.0, p<0.001) than controls. After training, patients improved their submaximal exercise capacity in a 6-minute walk test (from 590.7±65.5 m to 611.8±70.9 m, p<0.05) and reported a higher quality of life (p<0.01), but did not improve maximal exercise capacity. At follow-up, submaximal exercise capacity had increased further and improved quality of life was sustained. The controls improved their maximal exercise capacity (p<0.05), but not submaximal exercise capacity or quality of life after training. At follow-up, improvement of maximal exercise capacity was sustained. We believe that an individualised endurance training programme for Fontan patients improves submaximal exercise capacity and quality of life in Fontan patients and the effect on quality of life appears to be long-lasting.

How should COPD patients exercise during respiratory rehabilitation? Comparison of exercise modalities and intensities to treat skeletal muscle dysfunction

PubMed Central

Puhan, M; Schunemann, H; Frey, M; Scharplatz, M; Bachmann, L

2005-01-01

Background: Physical exercise is an important component of respiratory rehabilitation because it reverses skeletal muscle dysfunction, a clinically important manifestation of COPD associated with reduced health-related quality of life (HRQL) and survival. However, there is controversy regarding the components of the optimal exercise protocol. A study was undertaken to systematically evaluate and summarise randomised controlled trials (RCTs) comparing different exercise protocols for COPD patients. Methods: Six electronic databases, congress proceedings and bibliographies of included studies were searched without imposing language restrictions. Two reviewers independently screened all records and extracted data on study samples, interventions and methodological characteristics of included studies. Results: The methodological quality of the 15 included RCTs was low to moderate. Strength exercise led to larger improvements of HRQL than endurance exercise (weighted mean difference for Chronic Respiratory Questionnaire 0.27, 95% CI 0.02 to 0.52). Interval exercise seems to be of similar effectiveness as continuous exercise, but there are few data on clinically relevant outcomes. One small RCT which included patients with mild COPD compared the effect of high and low intensity exercise (at 80% and 40% of the maximum exercise capacity, respectively) and found larger physiological training effects from high intensity exercise. Conclusions: Strength exercise should be routinely incorporated in respiratory rehabilitation. There is insufficient evidence to recommend high intensity exercise for COPD patients and investigators should conduct larger high quality trials to evaluate exercise intensities in patients with moderate to severe COPD. PMID:15860711

Results of Skylab medical experiment M171: Metabolic activity

NASA Technical Reports Server (NTRS)

Michel, E. L.; Rummel, J. A.; Sawin, C. F.; Buderer, M. C.; Lem, J. D.

1974-01-01

The experiment was conducted to establish whether man's ability to perform mechanical work would be progressively altered as a result of exposure to the weightless environment of space flight. The Skylab crewmen exercised on a bicycle ergometer at workloads approximating 25, 50, and 75 percent of their maximum aerobic capacity. The physiological parameters monitored were respiratory gas exchange, blood pressure, and vectorcardiogram/heart rate. The results of these tests indicate that the crewmen had no significant decrement in their responses to exercise during their exposure to zero gravity. The results of the third manned Skylab mission (Skylab 4) are presented and a comparison is made of the overall results obtained from the three successively longer Skylab manned missions. The Skylab 4 crewmembers' 84-day in-flight responses to exercise were no worse and were probably better than the responses of the crewmen on the first two Skylab missions. Indications that exercise was an important contributing factor in maintaining this response are discussed.

Gait characteristics of individuals with multiple sclerosis before and after a 6-month aerobic training program.

PubMed

Rodgers, M M; Mulcare, J A; King, D L; Mathews, T; Gupta, S C; Glaser, R M

1999-07-01

Individuals who have multiple sclerosis (MS) typically experience problems with physical activities such as walking, resulting from the combined effects of skeletal muscle weakness, sensory disturbances, spasticity, gait ataxia, and reduction in aerobic capacity. The aim of this study was to determine whether a 6-mo exercise program designed for aerobic conditioning might also affect gait abnormalities in individuals with MS. Subjects included 18 individuals with MS who presented a range of disability. Passive range of motion (PROM) in the lower limbs was measured and gait analyzed before and after exercise conditioning. Three-dimensional kinematics, ground reaction forces (GRF), and electromyographic information were acquired as subjects walked at self-selected velocities. Hip PROM increased following conditioning. Mean walking velocity, cadence, and posterior shear GRF (push-off force) decreased. During walking, maximum ankle dorsiflexion decreased and ankle plantarflexion increased. Total knee flexion/extension range during the walking cycle decreased slightly as did maximum hip extension. Results suggest this 6-mo training program had minimal effect on gait abnormalities.

A Pilot Study: The Beneficial Effects of Combined Statin-exercise Therapy on Cognitive Function in Patients with Coronary Artery Disease and Mild Cognitive Decline.

PubMed

Toyama, Kensuke; Sugiyama, Seigo; Oka, Hideki; Hamada, Mari; Iwasaki, Yuri; Horio, Eiji; Rokutanda, Taku; Nakamura, Shinichi; Spin, Joshua M; Tsao, Philip S; Ogawa, Hisao

2017-01-01

Objective Hypercholesterolemia, a risk factor in cognitive impairment, can be treated with statins. However, cognitive decline associated with "statins" (HMG-CoA reductase inhibitors) is a clinical concern. This pilot study investigated the effects of combining statins and regular exercise on cognitive function in coronary artery disease (CAD) patients with prior mild cognitive decline. Methods We recruited 43 consecutive CAD patients with mild cognitive decline. These patients were treated with a statin and weekly in-hospital aerobic exercise for 5 months. We measured serum lipids, exercise capacity, and cognitive function using the mini mental state examination (MMSE). Results Low-density lipoprotein cholesterol levels were significantly decreased, and maximum exercise capacity (workload) was significantly increased in patients with CAD and mild cognitive decline after treatment compared with before. Combined statin-exercise therapy significantly increased the median (range) MMSE score from 24 (22-25) to 25 (23-27) across the cohort (p<0.01). Changes in body mass index (BMI) were significantly and negatively correlated with changes in the MMSE. After treatment, MMSE scores in the subgroup of patients that showed a decrease in BMI were significantly improved, but not in the BMI-increased subgroup. Furthermore, the patients already on a statin at the beginning of the trial displayed a more significant improvement in MMSE score than statin-naïve patients, implying that exercise might be the beneficial aspect of this intervention as regards cognition. In a multivariate logistic regression analysis adjusted for age >65 years, sex, and presence of diabetes mellitus, a decrease in BMI during statin-exercise therapy was significantly correlated with an increase in the MMSE score (odds ratio: 4.57, 95% confidence interval: 1.05-20.0; p<0.05). Conclusion Statin-exercise therapy may help improve cognitive dysfunction in patients with CAD and pre-existing mild cognitive decline.

Comparison of abdominal muscle activity and peak expiratory flow between forced vital capacity and fast expiration exercise.

PubMed

Ishida, Hiroshi; Suehiro, Tadanobu; Watanabe, Susumu

2017-04-01

[Purpose] The purpose of this investigation was to compare the activities of the abdominal muscles and peak expiratory flow between forced vital capacity and fast expiration exercise. [Subjects and Methods] Fifteen healthy male participated in this study. Peak expiratory flow and electromyographic activities of the rectus abdominis, external oblique, and internal oblique/transversus abdominis muscles were measured during forced vital capacity and fast expiration exercise and then peak amplitude and its appearance time were obtained. [Results] Peak expiratory flow values were significantly higher during fast expiration exercise than during forced vital capacity. The internal oblique/transversus abdominis muscles showed significantly higher peak amplitude during fast expiration exercise than during forced vital capacity. However, there were no significant differences between forced vital capacity and fast expiration exercise in the rectus abdominis and external oblique muscles. There was no difference in the appearance time of the peak amplitude between forced vital capacity and fast expiration exercise in any muscle. [Conclusion] Fast expiration exercise might be beneficial for increasing expiratory speed and neuromuscular activation of the internal oblique/transversus abdominis muscles compared to forced vital capacity. These findings could be considered when recommending a variation of expiratory muscle strength training as part of pulmonary rehabilitation programs.

[Leisure-time sport activities and cardiac outpatient therapy in coronary patients].

PubMed

Heitkamp, Hans-Christian; Schimpf, Thomas M; Hipp, Arno; Niess, Andreas

2005-03-01

Exercise intensity in coronary patients is controlled by heart rate measurements. Very few investigations have compared the maximum heart rate in cardiac outpatient groups, in leisure-time sport activities, and especially in swimming. Within different exercise conditions 21 coronary patients, nine in well-compensated cardiac condition joining a training group and twelve joining the exercise group with lower intensity, without signs of heart failure, engaged in an incremental bicycle ergometry. A six-lead ECG was derived at the same time with a 24-h ECG. The performance tolerance was measured by the pulse limit derived in 20 patients; one patient failed to show signs of subjective or objective ischemia. During a 24-h ECG monitoring, the patients took part in a 1-h standardized cardiac outpatient program, a standardized swimming program 4 x 25 m, and a typical self-selected leisure-time activity. The patients showed a peak work capacity of 2.2 W/kg and a symptom-free work capacity of 1.3 W/kg. The derived upper heart rate limit was passed during swimming by 19, during leisure-time activity by 16, and during cardiac outpatient program by two patients. The maximum of the mean overriding the limit occurred in leisure-time activity. Signs of ischemia occurred during ergometry in 15, during swimming training in ten patients, during leisure-time activity in eight, and during cardiac outpatient therapy in one. Arrhythmia < Lown IVa was documented on the ergometer in 15, during leisure-time sport activity in 15, during cardiac outpatient therapy in 17, and during swimming in eight patients. Arrhythmia Lown IVa occurred in one patient each during ergometry, leisure sports, and during the night. Coronary patients are in danger to exercise beyond the pulse limit during swimming and other leisure-time sports and not during cardiac outpatient therapy. The upper heart rate limit should be observed during swimming and other endurance leisure-time activities, and is of little importance during cardiac outpatient therapy.

Dose-Response of High-Intensity Training (HIT) on Atheroprotective miRNA-126 Levels

PubMed Central

Schmitz, Boris; Schelleckes, Katrin; Nedele, Johanna; Thorwesten, Lothar; Klose, Andreas; Lenders, Malte; Krüger, Michael; Brand, Eva; Brand, Stefan-Martin

2017-01-01

Aim: MicroRNA-126 (miR-126) exerts beneficial effects on vascular integrity, angiogenesis, and atherosclerotic plaque stability. The purpose of this investigation was to analyze the dose-response relationship of high-intensity interval training (HIIT) on miR-126-3p and -5p levels. Methods: Sixty-one moderately trained individuals (females = 31 [50.8%]; 22.0 ± 1.84 years) were consecutively recruited and allocated into three matched groups using exercise capacity. During a 4-week intervention a HIIT group performed three exercise sessions/week of 4 × 30 s at maximum speed (all-out), a progressive HIIT (proHIIT) group performed three exercise sessions/week of 4 × 30 s at maximum speed (all-out) with one extra session every week (up to 7 × 30 s) and a low-intensity training (LIT) control group performed three exercise sessions/week for 25 min <75% of maximum heart rate. Exercise miR-126-3p/-5p plasma levels were determined using capillary blood from earlobes. Results: No exercise-induced increase in miR-126 levels was detected at baseline, neither in the LIT (after 25 min low-intensity running) nor the HIIT groups (after 4 min of high-intensity running). After the intervention, the LIT group presented an increase in miR-126-3p, while in the HIIT group, miR-126-3p levels were still reduced (all p < 0.05). An increase for both, miR-126-3p and -5p levels (all p < 0.05, pre- vs. during and post-exercise) was detected in the proHIIT group. Between group analysis revealed that miR-126-3p levels after LIT and proHIIT increased by 2.12 ± 2.55 and 1.24 ± 2.46 units (all p < 0.01), respectively, compared to HIIT (−1.05 ± 2.6 units). Conclusions: LIT and proHIIT may be performed to increase individual miR-126 levels. HIIT without progression was less effective in increasing miR-126. PMID:28611681

Dose-Response of High-Intensity Training (HIT) on Atheroprotective miRNA-126 Levels.

PubMed

Schmitz, Boris; Schelleckes, Katrin; Nedele, Johanna; Thorwesten, Lothar; Klose, Andreas; Lenders, Malte; Krüger, Michael; Brand, Eva; Brand, Stefan-Martin

2017-01-01

Aim: MicroRNA-126 (miR-126) exerts beneficial effects on vascular integrity, angiogenesis, and atherosclerotic plaque stability. The purpose of this investigation was to analyze the dose-response relationship of high-intensity interval training (HIIT) on miR-126-3p and -5p levels. Methods: Sixty-one moderately trained individuals (females = 31 [50.8%]; 22.0 ± 1.84 years) were consecutively recruited and allocated into three matched groups using exercise capacity. During a 4-week intervention a HIIT group performed three exercise sessions/week of 4 × 30 s at maximum speed (all-out), a progressive HIIT (proHIIT) group performed three exercise sessions/week of 4 × 30 s at maximum speed (all-out) with one extra session every week (up to 7 × 30 s) and a low-intensity training (LIT) control group performed three exercise sessions/week for 25 min <75% of maximum heart rate. Exercise miR-126-3p/-5p plasma levels were determined using capillary blood from earlobes. Results: No exercise-induced increase in miR-126 levels was detected at baseline, neither in the LIT (after 25 min low-intensity running) nor the HIIT groups (after 4 min of high-intensity running). After the intervention, the LIT group presented an increase in miR-126-3p, while in the HIIT group, miR-126-3p levels were still reduced (all p < 0.05). An increase for both, miR-126-3p and -5p levels (all p < 0.05, pre- vs. during and post-exercise) was detected in the proHIIT group. Between group analysis revealed that miR-126-3p levels after LIT and proHIIT increased by 2.12 ± 2.55 and 1.24 ± 2.46 units (all p < 0.01), respectively, compared to HIIT (-1.05 ± 2.6 units). Conclusions: LIT and proHIIT may be performed to increase individual miR-126 levels. HIIT without progression was less effective in increasing miR-126.

Exercise and end-stage kidney disease: functional exercise capacity and cardiovascular outcomes.

PubMed

Parsons, Trisha L; King-Vanvlack, Cheryl E

2009-11-01

This review examined published reports of the impact of extradialytic and intradialytic exercise programs on physiologic aerobic exercise capacity, functional exercise endurance, and cardiovascular outcomes in individuals with ESKD. Studies spanning 30 years from the first published report of exercise in the ESKD population were reviewed. Studies conducted in the first half of the publication record focused on the efficacy of exercise training programs performed "off"-dialysis with respect to the modification of traditional cardiovascular risk factors, aerobic capacity, and its underlying determinants. In the latter half of the record, there had been a shift to include other client-centered goals such as physical function and quality of life. There is evidence that both intra- and extradialytic programs can significantly enhance aerobic exercise capacity, but moderate-intensity extradialytic programs may result in greater gains in those individuals who initially have extremely poor aerobic capacity. Functionally, substantive improvements in exercise endurance in excess of the minimum clinical significant difference can occur following either low- or moderate-intensity exercise regardless of the initial level of performance. Reductions in blood pressure and enhanced vascular functioning reported after predominantly intradialytic exercise programs suggest that either low- or moderate-intensity exercise programs can confer cardiovascular benefit. Regardless of prescription model, there was an overall lack of evidence regarding the impact of exercise-induced changes in exercise capacity, endurance, and cardiovascular function on a number of relevant health outcomes (survival, morbidity, and cardiovascular risk), and, more importantly, there is no evidence on the long-term impact of exercise and/or physical activity interventions on these health outcomes.

Effects of exercise on functional aerobic capacity in adults with fibromyalgia syndrome: A systematic review of randomized controlled trials.

PubMed

García-Hermoso, Antonio; Saavedra, Jose M; Escalante, Yolanda

2015-01-01

Patients with fibromyalgia present a reduced capacity of upper and lower limb physical performance and affect their independence in performing everyday activities. The purpose of the present systematic review was to summarize evidence for the effectiveness and structure of exercise programs on functional aerobic capacity in patients with fibromyalgia syndrome. Keyword searches were made of seven databases. The systematic review was limited to English language studies of people with FM that evaluated the effects of exercise programs on functional aerobic capacity (6-minute walk test). The criteria for inclusion were satisfied by 12 randomized controlled trial (RCT) studies. The main cumulative evidence indicates that the programs based on aerobic exercise alone and on aquatic exercises have large (effect size = 0.85) and moderate (effect size = 0.44) effects. Aerobic and aquatic exercises at the proper intensity favour the increased functional aerobic capacity of fibromyalgia patients; however, most works do not adequately detail the intensity of the exercises. Moderate intensity exercise (aerobic and aquatic exercise) performed at least two times per week and 30-60 minutes a day is effective for increasing functional aerobic capacity, favouring the daily activities of daily living in this population.

Elevated Nicotinamide Phosphoribosyl Transferase in Skeletal Muscle Augments Exercise Performance and Mitochondrial Respiratory Capacity Following Exercise Training

PubMed Central

Brouwers, Bram; Stephens, Natalie A.; Costford, Sheila R.; Hopf, Meghan E.; Ayala, Julio E.; Yi, Fanchao; Xie, Hui; Li, Jian-Liang; Gardell, Stephen J.; Sparks, Lauren M.; Smith, Steven R.

2018-01-01

Mice overexpressing NAMPT in skeletal muscle (NamptTg mice) develop higher exercise endurance and maximal aerobic capacity (VO2max) following voluntary exercise training compared to wild-type (WT) mice. Here, we aimed to investigate the mechanisms underlying by determining skeletal muscle mitochondrial respiratory capacity in NamptTg and WT mice. Body weight and body composition, tissue weight (gastrocnemius, quadriceps, soleus, heart, liver, and epididymal white adipose tissue), skeletal muscle and liver glycogen content, VO2max, skeletal muscle mitochondrial respiratory capacity (measured by high-resolution respirometry), skeletal muscle gene expression (measured by microarray and qPCR), and skeletal muscle protein content (measured by Western blot) were determined following 6 weeks of voluntary exercise training (access to running wheel) in 13-week-old male NamptTg (exercised NamptTg) mice and WT (exercised WT) mice. Daily running distance and running time during the voluntary exercise training protocol were recorded. Daily running distance (p = 0.51) and running time (p = 0.85) were not significantly different between exercised NamptTg mice and exercised WT mice. VO2max was higher in exercised NamptTg mice compared to exercised WT mice (p = 0.02). Body weight (p = 0.92), fat mass (p = 0.49), lean mass (p = 0.91), tissue weight (all p > 0.05), and skeletal muscle (p = 0.72) and liver (p = 0.94) glycogen content were not significantly different between exercised NamptTg mice and exercised WT mice. Complex I oxidative phosphorylation (OXPHOS) respiratory capacity supported by fatty acid substrates (p < 0.01), maximal (complex I+II) OXPHOS respiratory capacity supported by glycolytic (p = 0.02) and fatty acid (p < 0.01) substrates, and maximal uncoupled respiratory capacity supported by fatty acid substrates (p < 0.01) was higher in exercised NamptTg mice compared to exercised WT mice. Transcriptomic analyses revealed differential expression for genes involved in oxidative metabolism in exercised NamptTg mice compared to exercised WT mice, specifically, enrichment for the gene set related to the SIRT3-mediated signaling pathway. SIRT3 protein content correlated with NAMPT protein content (r = 0.61, p = 0.04). In conclusion, NamptTg mice develop higher exercise capacity following voluntary exercise training compared to WT mice, which is paralleled by higher mitochondrial respiratory capacity in skeletal muscle. The changes in SIRT3 targets suggest that these effects are due to remodeling of mitochondrial function. PMID:29942262

Slow loaded breathing training improves blood pressure, lung capacity and arm exercise endurance for older people with treated and stable isolated systolic hypertension.

PubMed

Ublosakka-Jones, Chulee; Tongdee, Phailin; Pachirat, Orathai; Jones, David A

2018-03-28

Hypertension and reduced lung function are important features of aging. Slow loaded breathing training reduces resting blood pressure and the question is whether this can also improve lung function. Thirty-two people (67 ± 5 years, 16 male) with controlled isolated systolic hypertension undertook an eight weeks randomised controlled training trial with an inspiratory load of 25% maximum inspiratory pressure (MIP) at 6 breaths per minute (slow loaded breathing; SLB) or deep breathing control (CON). Outcome measures were resting blood pressure (BP) and heart rate; MIP; lung capacity; chest and abdominal expansion; arm cranking exercise endurance at 50% heart rate reserve. Home based measurement of resting systolic BP decreased by 20 mm Hg (15 to 25) (Mean and 95%CI) for SLB and by 5 mm Hg (1 to 7) for CON. Heart rate and diastolic BP also decreased significantly for SLB but not CON. MIP increased by 15.8 cm H 2 O (11.8 to 19.8) and slow vital capacity by 0.21 L (0.15 to 0.27) for SLB but not for CON. Chest and abdominal expansion increased by 2.3 cm (2.05 to 2.55) and 2.5 cm (2.15 to 2.85), respectively for SLB and by 0.5 cm (0.26 to 0.74) and 1.7 cm (1.32 to 2.08) for CON. Arm exercise time increased by 4.9 min (3.65 to 5.15) for SLB with no significant change for CON. Slow inspiratory muscle training is not only effective in reducing resting BP, even in older people with well controlled isolated systolic hypertension but also increases inspiratory muscle strength, lung capacity and arm exercise duration. Copyright © 2018. Published by Elsevier Inc.

Feasibility and effects of a combined adjuvant high-intensity interval/strength training in breast cancer patients: a single-center pilot study.

PubMed

Schulz, Sebastian Viktor Waldemar; Laszlo, Roman; Otto, Stephanie; Prokopchuk, Dmytro; Schumann, Uwe; Ebner, Florian; Huober, Jens; Steinacker, Jürgen Michael

2018-06-01

To evaluate feasibility of an exercise intervention consisting of high-intensity interval endurance and strength training in breast cancer patients. Twenty-six women with nonmetastatic breast cancer were consecutively assigned to the exercise intervention- (n= 15, mean age 51.9 ± 9.8 years) and the control group (n = 11, mean age 56.9 ± 7.0 years). Cardiopulmonary exercise testing that included lactate sampling, one-repetition maximum tests and a HADS-D questionnaire were used to monitor patients both before and after a supervised six weeks period of either combined high-intensity interval endurance and strength training (intervention group, twice a week) or leisure training (control group). Contrarily to the control group, endurance (mean change of VO 2 , peak 12.0 ± 13.0%) and strength performance (mean change of cumulative load 25.9 ± 11.2%) and quality of life increased in the intervention group. No training-related adverse events were observed. Our guided exercise intervention could be used effectively for initiation and improvement of performance capacity and quality of life in breast cancer patients in a relatively short time. This might be especially attractive during medical treatment. Long-term effects have to be evaluated in randomized controlled studies also with a longer follow-up. Implications for Rehabilitation High-intensity interval training allows improvement of aerobic capacity within a comparable short time. Standard leisure training in breast cancer patients is rather suitable for the maintenance of performance capacity and quality of life. Guided high-intensity interval training combined with strength training can be used effectively for the improvement of endurance and strength capacity and also quality of life. After exclusion of contraindications, guided adjuvant high-intensity interval training combined with strength training can be safely used in breast cancer patients.

[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.

CETP Expression Protects Female Mice from Obesity-Induced Decline in Exercise Capacity.

PubMed

Cappel, David A; Lantier, Louise; Palmisano, Brian T; Wasserman, David H; Stafford, John M

2015-01-01

Pharmacological approaches to reduce obesity have not resulted in dramatic reductions in the risk of coronary heart disease (CHD). Exercise, in contrast, reduces CHD risk even in the setting of obesity. Cholesteryl Ester Transfer Protein (CETP) is a lipid transfer protein that shuttles lipids between serum lipoproteins and tissues. There are sexual-dimorphisms in the effects of CETP in humans. Mice naturally lack CETP, but we previously reported that transgenic expression of CETP increases muscle glycolysis in fasting and protects against insulin resistance with high-fat diet (HFD) feeding in female but not male mice. Since glycolysis provides an important energy source for working muscle, we aimed to define if CETP expression protects against the decline in exercise capacity associated with obesity. We measured exercise capacity in female mice that were fed a chow diet and then switched to a HFD. There was no difference in exercise capacity between lean, chow-fed CETP female mice and their non-transgenic littermates. Female CETP transgenic mice were relatively protected against the decline in exercise capacity caused by obesity compared to WT. Despite gaining similar fat mass after 6 weeks of HFD-feeding, female CETP mice showed a nearly two-fold increase in run distance compared to WT. After an additional 6 weeks of HFD-feeding, mice were subjected to a final exercise bout and muscle mitochondria were isolated. We found that improved exercise capacity in CETP mice corresponded with increased muscle mitochondrial oxidative capacity, and increased expression of peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α). These results suggest that CETP can protect against the obesity-induced impairment in exercise capacity and may be a target to improve exercise capacity in the context of obesity.

CETP Expression Protects Female Mice from Obesity-Induced Decline in Exercise Capacity

PubMed Central

Cappel, David A.; Lantier, Louise; Palmisano, Brian T.; Wasserman, David H.; Stafford, John M.

2015-01-01

Pharmacological approaches to reduce obesity have not resulted in dramatic reductions in the risk of coronary heart disease (CHD). Exercise, in contrast, reduces CHD risk even in the setting of obesity. Cholesteryl Ester Transfer Protein (CETP) is a lipid transfer protein that shuttles lipids between serum lipoproteins and tissues. There are sexual-dimorphisms in the effects of CETP in humans. Mice naturally lack CETP, but we previously reported that transgenic expression of CETP increases muscle glycolysis in fasting and protects against insulin resistance with high-fat diet (HFD) feeding in female but not male mice. Since glycolysis provides an important energy source for working muscle, we aimed to define if CETP expression protects against the decline in exercise capacity associated with obesity. We measured exercise capacity in female mice that were fed a chow diet and then switched to a HFD. There was no difference in exercise capacity between lean, chow-fed CETP female mice and their non-transgenic littermates. Female CETP transgenic mice were relatively protected against the decline in exercise capacity caused by obesity compared to WT. Despite gaining similar fat mass after 6 weeks of HFD-feeding, female CETP mice showed a nearly two-fold increase in run distance compared to WT. After an additional 6 weeks of HFD-feeding, mice were subjected to a final exercise bout and muscle mitochondria were isolated. We found that improved exercise capacity in CETP mice corresponded with increased muscle mitochondrial oxidative capacity, and increased expression of peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α). These results suggest that CETP can protect against the obesity-induced impairment in exercise capacity and may be a target to improve exercise capacity in the context of obesity. PMID:26313355

Resistance to Aerobic Exercise Training Causes Metabolic Dysfunction and Reveals Novel Exercise-Regulated Signaling Networks

PubMed Central

Lessard, Sarah J.; Rivas, Donato A.; Alves-Wagner, Ana B.; Hirshman, Michael F.; Gallagher, Iain J.; Constantin-Teodosiu, Dumitru; Atkins, Ryan; Greenhaff, Paul L.; Qi, Nathan R.; Gustafsson, Thomas; Fielding, Roger A.; Timmons, James A.; Britton, Steven L.; Koch, Lauren G.; Goodyear, Laurie J.

2013-01-01

Low aerobic exercise capacity is a risk factor for diabetes and a strong predictor of mortality, yet some individuals are “exercise-resistant” and unable to improve exercise capacity through exercise training. To test the hypothesis that resistance to aerobic exercise training underlies metabolic disease risk, we used selective breeding for 15 generations to develop rat models of low and high aerobic response to training. Before exercise training, rats selected as low and high responders had similar exercise capacities. However, after 8 weeks of treadmill training, low responders failed to improve their exercise capacity, whereas high responders improved by 54%. Remarkably, low responders to aerobic training exhibited pronounced metabolic dysfunction characterized by insulin resistance and increased adiposity, demonstrating that the exercise-resistant phenotype segregates with disease risk. Low responders had impaired exercise-induced angiogenesis in muscle; however, mitochondrial capacity was intact and increased normally with exercise training, demonstrating that mitochondria are not limiting for aerobic adaptation or responsible for metabolic dysfunction in low responders. Low responders had increased stress/inflammatory signaling and altered transforming growth factor-β signaling, characterized by hyperphosphorylation of a novel exercise-regulated phosphorylation site on SMAD2. Using this powerful biological model system, we have discovered key pathways for low exercise training response that may represent novel targets for the treatment of metabolic disease. PMID:23610057

Effect of Body Mass Index on Exercise Capacity in Patients With Hypertrophic Cardiomyopathy.

PubMed

Larsen, Carolyn M; Ball, Caroline A; Hebl, Virginia B; Ong, Kevin C; Siontis, Konstantinos C; Olson, Thomas P; Ackerman, Michael J; Ommen, Steve R; Allison, Thomas G; Geske, Jeffrey B

2018-01-01

The objective of this study was to evaluate the relation between body mass index (BMI), exercise capacity, and symptoms in patients with hypertrophic cardiomyopathy (HC) and to utilize results of cardiopulmonary exercise tests (CPX) and transthoracic echocardiograms to understand the mechanism(s) of reduced exercise capacity across body mass index groups. Over a 6-year period, 510 consecutive patients with HC seen at a tertiary referral center underwent (CPX) and a transthoracic echocardiogram. Increasing BMI was associated with decreased exercise capacity as assessed by peak VO 2 (ml/kg/min). However, the prevalence of cardiac impairment did not vary by BMI group. In conclusion, these findings suggest that in some patients with hypertrophic cardiomyopathy, cardiac impairment is not the primary cause of exercise limitation and weight loss may result in improved exercise capacity. Copyright © 2017 Elsevier Inc. All rights reserved.

Aerobic exercise deconditioning and countermeasures during bed rest.

PubMed

Lee, Stuart M C; Moore, Alan D; Everett, Meghan E; Stenger, Michael B; Platts, Steven H

2010-01-01

Bed rest is a well-accepted model for spaceflight in which the physiologic adaptations, particularly in the cardiovascular system, are studied and potential countermeasures can be tested. Bed rest without countermeasures results in reduced aerobic capacity and altered submaximal exercise responses. Aerobic endurance and factors which may impact prolonged exercise, however, have not been well studied. The initial loss of aerobic capacity is rapid, occurring in parallel with the loss of plasma volume. Thereafter, the reduction in maximal aerobic capacity proceeds more slowly and is influenced by central and peripheral adaptation. Exercise capacity can be maintained during bed rest and may be improved during recovery with appropriate countermeasures. Plasma volume restoration, resistive exercise, orthostatic stress, aerobic exercise, and aerobic exercise plus orthostatic stress all have been tested with varying levels of success. However, the optimal combination of elements-exercise modality, intensity, duration, muscle groups exercised and frequency of aerobic exercise, orthostatic stress, and supplementary resistive or anaerobic exercise training-has not been systematically evaluated. Currently, frequent (at least 3 days per week) bouts of intense exercise (interval-style and near maximal) with orthostatic stress appears to be the most efficacious method to protect aerobic capacity during bed rest. Further refinement of protocols and countermeasure hardware may be necessary to insure the success of countermeasures in the unique environment of space.

Physiological responses of young thoroughbred horses to intermittent high-intensity treadmill training

PubMed Central

2013-01-01

Background Training of young Thoroughbred horses must balance development of cardiopulmonary function and aerobic capacity with loading of the musculoskeletal system that can potentially cause structural damage and/or lameness. High-speed equine treadmills are sometimes used to supplement exercise on a track in the training of young Thoroughbreds because the horse can run at high speeds but without the added weight of a rider. We tested the hypothesis that intermittent high-intensity exercise on a treadmill of young Thoroughbred horses entering training can enhance development of aerobic capacity (Vo2max) and running performance more than conventional training under saddle, and do so without causing lameness. Results Twelve yearling Thoroughbreds trained for 8 months with conventional riding (C) only, conventional riding plus a short (2 month, S) interval of once-per-week high-intensity treadmill exercise, or a long (8 month, L) interval of once-per-week high-intensity treadmill exercise. Three treadmill exercise tests evaluated Vo2max, oxygen transport and running performance variables in June of the yearling year (only for L), October of the yearling year and April of the 2-year-old year. No horses experienced lameness during the study. Aerobic capacity increased in all groups after training. In both October and April, Vo2max in L was higher than in C, but did not differ between L and S or S and C. Running speeds eliciting Vo2max also increased in all groups after training, with S (809 ± 3 m/s) and L (804 ± 9 m/s) higher than C (764 ± 27 m/s). Maximum heart rate decreased for all groups after training. Hematocrit and hemoglobin concentration increased for L throughout training. Conclusions Young Thoroughbred horses can increase aerobic capacity and running performance more than by strictly using track training under saddle with the addition of intermittent high-intensity treadmill exercise, and they can do so without experiencing lameness. This finding suggests that young racehorses might be able to achieve higher aerobic fitness during training without subjecting their musculoskeletal systems to increased loading and risk of developing lameness. The findings of this preliminary study do not indicate a specific protocol to best achieve this goal. PMID:23957961

The impact of electronic mail versus print delivery of an exercise program on muscular strength and aerobic capacity in people with type 2 diabetes.

PubMed

Taylor, J David

2008-09-01

Previous research indicates that the Internet, electronic mail (e-mail), and printed materials can be used to deliver interventions to improve physical activity in people with type 2 diabetes. However, no studies have been conducted investigating the effect of e-mail or print delivery of an exercise program on muscular strength and aerobic capacity in people with type 2 diabetes. The purpose of this clinical trial was to investigate the impact of e-mail vs. print delivery of an exercise program on muscular strength and aerobic capacity in people with type 2 diabetes. Nineteen participants with type 2 diabetes were allocated to either a group that was delivered a prescribed exercise program using e-mail (e-mail group, n = 10) or a group that was delivered the same prescribed exercise program in print form (print group, n = 9). Chest press and leg press estimated one-repetition maximum (1-RM) scores as well as estimated peak oxygen uptake ([latin capital V with dot above]O2peak) were measured at baseline and follow-up. Intention-to-treat analysis indicated significant improvements in chest press (mean = 7.00 kg, p = 0.001, effect size = 2.22) and leg press (mean = 19.32 kg, p = 0.002, effect size = 1.98) 1-RM scores and [latin capital V with dot above]O2peak (mean = 9.38 mL of oxygen uptake per kilogram of body mass per minute, p = 0.01, effect size = 1.45) within the e-mail group. Within the print group, significant improvements in chest press (mean = 9.13 kg, p = 0.01, effect size = 1.49) and leg press (mean = 16.68 kg, p = 0.01, effect size = 1.31) 1-RM scores and [latin capital V with dot above]O2peak (mean = 5.14 ml of oxygen uptake per kilogram of body mass per minute, p = 0.03, effect size = 1.14) were found. No significant between-group differences in improvements were found. Clinicians can deliver a prescribed exercise program, either by e-mail or in print form, to significantly improve muscular strength and aerobic capacity in people with type 2 diabetes, and expect similar outcomes.

L-Arginine Affects Aerobic Capacity and Muscle Metabolism in MELAS (Mitochondrial Encephalomyopathy, Lactic Acidosis and Stroke-Like Episodes) Syndrome

PubMed Central

Rodan, Lance H.; Wells, Greg D.; Banks, Laura; Thompson, Sara; Schneiderman, Jane E.; Tein, Ingrid

2015-01-01

Objective To study the effects of L-arginine (L-Arg) on total body aerobic capacity and muscle metabolism as assessed by 31Phosphorus Magnetic Resonance Spectroscopy (31P-MRS) in patients with MELAS (Mitochondrial Encephalomyopathy with Lactic Acidosis and Stroke-like episodes) syndrome. Methods We performed a case control study in 3 MELAS siblings (m.3243A>G tRNAleu(UUR) in MTTL1 gene) with different % blood mutant mtDNA to evaluate total body maximal aerobic capacity (VO2peak) using graded cycle ergometry and muscle metabolism using 31P-MRS. We then ran a clinical trial pilot study in MELAS sibs to assess response of these parameters to single dose and a 6-week steady-state trial of oral L-Arginine. Results At baseline (no L-Arg), MELAS had lower serum Arg (p = 0.001). On 31P-MRS muscle at rest, MELAS subjects had increased phosphocreatine (PCr) (p = 0.05), decreased ATP (p = 0.018), and decreased intracellular Mg2+ (p = 0.0002) when compared to matched controls. With L-arginine therapy, the following trends were noted in MELAS siblings on cycle ergometry: (1) increase in mean % maximum work at anaerobic threshold (AT) (2) increase in % maximum heart rate at AT (3) small increase in VO2peak. On 31P-MRS the following mean trends were noted: (1) A blunted decrease in pH after exercise (less acidosis) (2) increase in Pi/PCr ratio (ADP) suggesting increased work capacity (3) a faster half time of PCr recovery (marker of mitochondrial activity) following 5 minutes of moderate intensity exercise (4) increase in torque. Significance These results suggest an improvement in aerobic capacity and muscle metabolism in MELAS subjects in response to supplementation with L-Arg. Intramyocellular hypomagnesemia is a novel finding that warrants further study. Classification of Evidence Class III evidence that L-arginine improves aerobic capacity and muscle metabolism in MELAS subjects. Trial Registration ClinicalTrials.gov NCT01603446. PMID:25993630

Left ventricular assist device: exercise capacity evolution and rehabilitation added value.

PubMed

Lamotte, Michel X; Chimenti, Sara; Deboeck, Gael; Gillet, Alexis; Kacelenenbogen, Raymond; Strapart, Jonathan; Vandeneynde, Frédéric; Van Nooten, Guido; Antoine, Martine

2018-06-01

With more than 15,000 implanted patients worldwide and a survival rate of 80% at 1-year and 59% at 5-years, left ventricular assist device (LVAD) implantation has become an interesting strategy in the management of heart failure patients who are resistant to other kinds of treatment. There are limited data in the literature on the change over time of exercise capacity in LVAD patients, as well as limited knowledge about the beneficial effects that rehabilitation might have on these patients. Therefore, the aim of our study was to evaluate the evolution of exercise capacity on a cohort of patients implanted with the same device (HeartWare © ) and to analyse the potential impact of rehabilitation. Sixty-two patients implanted with a LVAD between June 2011 and June 2015 were screened. Exercise capacity was evaluated by cardiopulmonary exercise testing at 6 weeks, 6 and 12 months after implantation. We have observed significant differences in the exercise capacity and evolution between the trained and non-trained patients. Some of the trained patients nearly normalised their exercise capacity at the end of the rehabilitation programme. Exercise capacity of patient implanted with a HeartWare © LVAD increased in the early period after implantation. Rehabilitation allowed implanted patients to have a significantly better evolution compared to non-rehabilitated patients.

Maximum Oxygen Uptake During and After Long-Duration Space Flight

NASA Technical Reports Server (NTRS)

Moore, Alan D., Jr.; Evetts, Simon N.; Feiveson, Alan H.; Lee, Stuart M. C.; McCleary. Frank A.; Platts, Steven H.

2010-01-01

Decreased maximum oxygen consumption (VO2max) during and after space flight may impair a crewmember s ability to perform mission-critical work that is high intensity and/or long duration in nature (Human Research Program Integrated Research Plan Risk 2.1.2: Risk of Reduced Physical Performance Capabilities Due to Reduced Aerobic Capacity). When VO2max was measured in Space Shuttle experiments, investigators reported that it did not change during short-duration space flight but decreased immediately after flight. Similar conclusions, based on the heart rate (HR) response of Skylab crewmembers, were made previously concerning long-duration space flight. Specifically, no change in the in-flight exercise HR response in 8 of 9 Skylab crewmembers indicated that VO2max was maintained during flight, but the elevated exercise HR after flight indicated that VO2max was decreased after landing. More recently, a different pattern of in-flight exercise HR response, and assumed changes in VO2max, emerged from routine testing of International Space Station (ISS) crewmembers. Most ISS crewmembers experience an elevated in-flight exercise HR response early in their mission, with a gradual return toward preflight levels as the mission progresses. Similar to previous reports, exercise HR is elevated after ISS missions and returns to preflight levels by 30 days after landing. VO2max has not been measured either during or after long-duration space flight. The purposes of the ISS VO2max experiment are (1) to measure VO2max during and after long-duration spaceflight, and (2) to determine if submaximal exercise test results can be used to accurately estimate VO 2max.

Effects of adding exercise to a 16-week very low-calorie diet in obese, insulin-dependent type 2 diabetes mellitus patients.

PubMed

Snel, Marieke; Gastaldelli, Amalia; Ouwens, D Margriet; Hesselink, Matthijs K C; Schaart, Gert; Buzzigoli, Emma; Frölich, Marijke; Romijn, Johannes A; Pijl, Hanno; Meinders, A Edo; Jazet, Ingrid M

2012-07-01

Reduction of 50% excess body weight, using a very low-calorie diet (VLCD; 450 kcal/d) improves insulin sensitivity in obese type 2 diabetes mellitus patients. The objective of the study was to evaluate whether adding exercise to the VLCD has additional benefits. This was a randomized intervention study. The study was conducted at a clinical research center in an academic medical center. Twenty-seven obese [body mass index 37.2 ± 0.9 kg/m(2) (mean ± sem)] insulin-treated type 2 diabetes mellitus patients. Patients followed a 16-wk VLCD. Thirteen of them simultaneously participated in an exercise program (E) consisting of 1-h, in-hospital training and four 30-min training sessions on a cycloergometer weekly. Insulin resistance was measured by a hyperinsulinemic euglycemic clamp. Insulin signaling, mitochondrial DNA (mtDNA) content, and intramyocellular lipid content was measured in skeletal muscle biopsies. Baseline characteristics were identical in both groups. Substantial weight loss occurred (-23.7 ± 1.7 kg VLCD-only vs. -27.2 ± 1.9 kg VLCD+E, P = NS within groups). The exercise group lost more fat mass. Insulin-stimulated glucose disposal increased similarly in both study groups [15.0 ± 0.9 to 39.2 ± 4.7 μmol/min(-1) · kg lean body mass (LBM(-1)) VLCD-only vs. 17.0 ± 1.0 to 37.5 ± 3.5 μmol/min(-1) · kg LBM(-1) in VLCD+E], as did phosphorylation of the phosphatidylinositol 3-kinase-protein kinase B/AKT insulin signaling pathway. In contrast, skeletal muscle mtDNA content increased only in the VLCD+E group (1211 ± 185 to 2288 ± 358, arbitrary units, P = 0.016 vs. 1397 ± 240 to 1196 ± 179, P = NS, VLCD-only group). Maximum aerobic capacity also only increased significantly in the VLCD+E group (+6.6 ± 1.7 ml/min(-1) · kg LBM(-1) vs. +0.7 ± 1.5 ml/min(-1) · kg LBM(-1) VLCD-only, P = 0.017). Addition of exercise to a 16-wk VLCD induces more fat loss. Exercise augments maximum aerobic capacity and skeletal muscle mtDNA content. These changes are, however, not reflected in a higher insulin-stimulated glucose disposal rate.

Effects of adipose tissue distribution on maximum lipid oxidation rate during exercise in normal-weight women.

PubMed

Isacco, L; Thivel, D; Duclos, M; Aucouturier, J; Boisseau, N

2014-06-01

Fat mass localization affects lipid metabolism differently at rest and during exercise in overweight and normal-weight subjects. The aim of this study was to investigate the impact of a low vs high ratio of abdominal to lower-body fat mass (index of adipose tissue distribution) on the exercise intensity (Lipox(max)) that elicits the maximum lipid oxidation rate in normal-weight women. Twenty-one normal-weight women (22.0 ± 0.6 years, 22.3 ± 0.1 kg.m(-2)) were separated into two groups of either a low or high abdominal to lower-body fat mass ratio [L-A/LB (n = 11) or H-A/LB (n = 10), respectively]. Lipox(max) and maximum lipid oxidation rate (MLOR) were determined during a submaximum incremental exercise test. Abdominal and lower-body fat mass were determined from DXA scans. The two groups did not differ in aerobic fitness, total fat mass, or total and localized fat-free mass. Lipox(max) and MLOR were significantly lower in H-A/LB vs L-A/LB women (43 ± 3% VO(2max) vs 54 ± 4% VO(2max), and 4.8 ± 0.6 mg min(-1)kg FFM(-1)vs 8.4 ± 0.9 mg min(-1)kg FFM(-1), respectively; P < 0.001). Total and abdominal fat mass measurements were negatively associated with Lipox(max) (r = -0.57 and r = -0.64, respectively; P < 0.01) and MLOR [r = -0.63 (P < 0.01) and r = -0.76 (P < 0.001), respectively]. These findings indicate that, in normal-weight women, a predominantly abdominal fat mass distribution compared with a predominantly peripheral fat mass distribution is associated with a lower capacity to maximize lipid oxidation during exercise, as evidenced by their lower Lipox(max) and MLOR. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Lack of ventilatory threshold in patients with chronic obstructive pulmonary disease.

PubMed

Midorikawa, J; Hida, W; Taguchi, O; Okabe, S; Kurosawa, H; Mizusawa, A; Ogawa, H; Ebihara, S; Kikuchi, Y; Shirato, K

1997-01-01

We investigated whether the ventilatory threshold (VET) could be detected in 25 patients with severe chronic obstructive pulmonary disease (COPD). Exercise on a treadmill was performed until symptom-limited maximum oxygen uptake (VO2SL) was obtained. VET was absent in 14 patients (56%, VET(-) group) and present in the others (44%, VET(+) group). Basal pulmonary functions and dyspnea index (VE,SL/MVV) were not different between the two groups. Endurance time and exercise tolerance (VO2SL/bw) were significantly less in VET(-) than in VET(+). In the former group, PaO2 and pH at maximal exercise decreased and PaCO2 increased significantly, but HCO3- did not change compared with the corresponding values before exercise. In the latter group, PaCO2 at maximal exercise increased significantly, and pH and HCO3- decreased significantly compared with the values before exercise, but PaO2 did not. The changes in PaO2 and PaCO2 were not different between the two groups, but changes in pH and HCO3- in VET(+) were greater than those in VET(-). These results suggest that the absence of VET in some COPD patients indicates a lower exercise capacity without producing metabolic acidosis. This may be caused by rapidly developing dyspnea.

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.

Effects of exercise training in patients with idiopathic pulmonary arterial hypertension.

PubMed

de Man, F S; Handoko, M L; Groepenhoff, H; van 't Hul, A J; Abbink, J; Koppers, R J H; Grotjohan, H P; Twisk, J W R; Bogaard, H-J; Boonstra, A; Postmus, P E; Westerhof, N; van der Laarse, W J; Vonk-Noordegraaf, A

2009-09-01

We determined the physiological effects of exercise training on exercise capacity and quadriceps muscle function in patients with idiopathic pulmonary arterial hypertension (iPAH). In total, 19 clinically stable iPAH patients (New York Heart Association II-III) underwent a supervised exercise training programme for the duration of 12 weeks. Maximal capacity, endurance capacity and quadriceps function were assessed at baseline and after 12 weeks. In 12 patients, serial quadriceps muscle biopsies were obtained. 6-min walk distance and peak exercise capacity did not change after training. However, endurance capacity improved significantly after training, demonstrated by a shift of the anaerobic threshold to a higher workload (from 32+/-5 to 46+/-6 W; p = 0.003) together with an increase in exercise endurance time (p<0.001). Moreover, exercise training increased quadriceps strength by 13% (p = 0.005) and quadriceps endurance by 34% (p = 0.001). Training enhanced aerobic capacity of the quadriceps, by increasing capillarisation (1.36+/-0.10 to 1.78+/-0.13 capillaries per muscle fibre; p<0.001) and oxidative enzyme activity, especially of the type-I (slow) muscle fibres. No changes were found in cross-sectional area and fibre type distribution. Exercise training in iPAH improves exercise endurance and quadriceps muscle function, which is also reflected by structural changes of the quadriceps.

Cardio-vascular reserve index (CVRI) during exercise complies with the pattern assumed by the cardiovascular reserve hypothesis.

PubMed

Segel, Michael J; Bobrovsky, Ben-Zion; Gabbay, Itay E; Ben-Dov, Issahar; Reuveny, Ronen; Gabbay, Uri

2017-05-01

The Cardio-vascular reserve index (CVRI) had been empirically validated in diverse morbidities as a quantitative estimate of the reserve assumed by the cardiovascular reserve hypothesis. This work evaluates whether CVRI during exercise complies with the cardiovascular reserve hypothesis. Retrospective study based on a database of patients who underwent cardio-pulmonary exercise testing (CPX) for diverse indications. Patient's physiological measurements were retrieved at four predefined CPX stages (rest, anaerobic threshold, peak exercise and after 2min of recovery). CVRI was individually calculated retrospectively at each stage. Mean CVRI at rest was 0.81, significantly higher (p<0.001) than at all other stages. CVRI decreased with exercise, reaching an average at peak exercise of 0.35, significant lower than at other stages (p<0.001) and very similar regardless of exercise capacity (mean CVRI 0.33-0.37 in 4 groups classified by exercise capacity, p>0.05). CVRI after 2min of recovery rose considerably, most in the group with the best exercise capacity and least in those with the lowest exercise capacity. CVRI during exercise fits the pattern predicted by the cardiovascular reserve hypothesis. CVRI decreased with exercise reaching a minimum at peak exercise and rising with recovery. The CVRI nadir at peak exercise, similar across groups classified by exercise capacity, complies with the assumed exhaustion threshold. The clinical utility of CVRI should be further evaluated. Copyright © 2017 Elsevier B.V. All rights reserved.

Exercise Capacity and the Obesity Paradox in Heart Failure: The FIT (Henry Ford Exercise Testing) Project.

PubMed

McAuley, Paul A; Keteyian, Steven J; Brawner, Clinton A; Dardari, Zeina A; Al Rifai, Mahmoud; Ehrman, Jonathan K; Al-Mallah, Mouaz H; Whelton, Seamus P; Blaha, Michael J

2018-05-03

To assess the influence of exercise capacity and body mass index (BMI) on 10-year mortality in patients with heart failure (HF) and to synthesize these results with those of previous studies. This large biracial sample included 774 men and women (mean age, 60±13 years; 372 [48%] black) with a baseline diagnosis of HF from the Henry Ford Exercise Testing (FIT) Project. All patients completed a symptom-limited maximal treadmill stress test from January 1, 1991, through May 31, 2009. Patients were grouped by World Health Organization BMI categories for Kaplan-Meier survival analyses and stratified by exercise capacity (<4 and ≥4 metabolic equivalents [METs] of task). Associations of BMI and exercise capacity with all-cause mortality were assessed using multivariable-adjusted Cox proportional hazards models. During a mean follow-up of 10.1±4.6 years, 380 patients (49%) died. Kaplan-Meier survival plots revealed a significant positive association between BMI category and survival for exercise capacity less than 4 METs (log-rank, P=.05), but not greater than or equal to 4 METs (P=.76). In the multivariable-adjusted models, exercise capacity (per 1 MET) was inversely associated, but BMI was not associated, with all-cause mortality (hazard ratio, 0.89; 95% CI, 0.85-0.94; P<.001 and hazard ratio, 0.99; 95% CI, 0.97-1.01; P=.16, respectively). Maximal exercise capacity modified the relationship between BMI and long-term survival in patients with HF, upholding the presence of an exercise capacity-obesity paradox dichotomy as observed over the short-term in previous studies. Copyright © 2018 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.

Effects of detraining on anthropometry, aerobic capacity and functional ability in adults with Down syndrome.

PubMed

Boer, P H

2018-01-01

Structured exercise has shown to improve parameters of functional fitness in adults with Down syndrome (DS). However, few, if any, continue to exercise after exercise intervention studies. Consequently, the purpose of this study was to determine the effects of detraining on anthropometry, aerobic capacity and functional ability of adults with DS. In a previous study, forty-two participants either performed 12 weeks of interval training, continuous aerobic training or no training (CON). After 3 months of detraining, the same participants were tested again for anthropometry, aerobic capacity, leg strength and functional ability. Significant reductions in maximal aerobic capacity, time to exhaustion and both functional test items were reported for both exercise groups compared to CON (p < .05). No significant differences were reported between the exercise groups concerning aerobic and functional capacity reductions. Detraining occurred significantly in both exercise groups regarding parameters associated with aerobic and functional capacity. © 2017 John Wiley & Sons Ltd.

The relationship between exercise capacity and masked hypertension in sedentary patients with diabetes mellitus.

PubMed

Akilli, Hakan; Kayrak, Mehmet; Arıbas, Alpay; Tekinalp, Mehmet; Ayhan, Selim Suzi; Gündüz, Mehmet; Alibasic, Hajrudin; Altunbas, Gokhan; Yazıcı, Mehmet

2014-01-01

Although exaggerated blood pressure responses (EBPR) to exercise have been related to future hypertension and masked hypertension (MHT), the relationship between exercise capacity and MHT remains unclear. A sedentary life style has been related to increased cardiovascular mortality, diabetes mellitus (DM), and hypertension. In this study, we aimed to examine the relationship between exercise capacity and MHT in sedentary patients with DM. This study included 85 sedentary and normotensive patients with DM. Each patient's daily physical activity level was assessed according to the INTERHEART study. All patients underwent an exercise treadmill test, and exercise duration and capacity were recorded. Blood pressure (BP) was recorded during all exercise stages and BP values ≥ 200/110 mmHg were accepted as EBPR. MHT was diagnosed in patients having an office BP <140/90 mmHg and a daytime ambulatory BP >135/85 mmHg. Patients were divided into two groups according to their ambulatory BP monitoring (MHT and normotensive group). The prevalence of MHT was 28.2%. Exercise duration and capacity were lower in the MHT group than in the normotensive group (p<0.05) and were negatively correlated with age, HbA1c, mean daytime BP, and mean 24 hour BP. Peak exercise systolic BP and the frequency of EBPR were both increased in the MHT group (25.0% and 8.1%, respectively, p=0.03). According to a multivariate regression, exercise capacity (OR: 0.61, CI95%: 0.39-0.95, p=0.03), EBPR (OR: 9.45, CI95%: 1.72-16.90, p=0.01), and the duration of DM (OR: 0.84, CI95%: 0.71-0.96, p=0.03) were predictors of MHT. Exercise capacity, EBPR, and the duration of DM were predictors of MHT in sedentary subjects with DM.

Anthropometric and physiological profiles of active blind Malaysian males.

PubMed

Singh, R; Singh, H J

1993-12-01

Cardiopulmonary capacities of twelve adults (aged between 14 to 44 years) with varying degrees of blindness engaged in regular recreational activities were compared with twelve age-matched normal sighted healthy males (control group) who were also involved in regular recreational activities. Maximum oxygen consumption (VO2max) was measured directly during exhaustive exercise test on a cycle ergometer. Forced vital capacity, leg strength and power were determined by spirometry, standing long jump and vertical jump respectively. No significant differences in VO2max, forced vital capacity and leg strength and power were observed between the blind and the control groups. No anthropometric differences were evident between the two groups. The results show therefore that the visually handicapped who are active can have a similar level of physical fitness, lung function and explosive leg strength as those of their active sighted counterparts.

Self-reported quality of life before and after aerobic exercise training in individuals with hypertension: a randomised-controlled trial.

PubMed

Maruf, Fatai A; Akinpelu, Aderonke O; Salako, Babatunde L

2013-07-01

The Effects of Aerobic Exercise Training (AET) on self-reported Quality of Life (QoL) in people with hypertension have been previously documented. However, data on black populations, especially from Africa, seem not to be available. This study investigated the effects of AET on QoL and exercise capacity in Nigerians on treatment for essential hypertension. This randomised-controlled trial involved newly diagnosed individuals, with mild-to-moderate essential hypertension randomly assigned to antihypertensive drugs (ADs) alone (control: n = 60) and AET+ADs (exercise: n = 60) groups. The study lasted for 12 weeks. QoL was measured using the World Health Organization QoL Short Form (WHOQoL-BREF) and exercise capacity was assessed using the Rockport Fitness Walk Test pre- and post-study. Physical health, psychological health, and social relationships domains of QoL improved significantly in the exercise and control groups post-intervention. The environment domain of QoL and exercise capacity improved significantly in only the exercise group. There were larger improvements in the physical health, psychological health, and environment domains of QoL, and exercise capacity in the exercise group. Aerobic exercise improves QoL and exercise capacity in individuals with essential hypertension. © 2013 The Authors. Applied Psychology: Health and Well-Being © 2013 The International Association of Applied Psychology.

Single and Concurrent Effects of Endurance and Resistance Training on Pulmonary Function

PubMed Central

Khosravi, Maryam; Tayebi, Seyed Morteza; Safari, Hamed

2013-01-01

Objective(s): As not only few evidences but also contradictory results exist with regard to the effects of resistance training (RT) and resistance plus endurance training (ERT) on respiratory system, so the purpose of this research was therefore to study single and concurrent effects of endurance and resistance training on pulmonary function. Materials and Methods: Thirty seven volunteer healthy inactive women were randomly divided into 4 groups: without training as control (C), Endurance Training (ET), RT, and ERT. A spirometry test was taken 24 hrs before and after the training course. The training period (8 weeks, 3 sessions/week) for ET was 20-26 min/session running with 60-80% maximum heart rate (HR max); for RT two circuits/session, 40-60s for each exercise with 60-80% one repetition maximum (1RM), and 1 and 3 minutes active rest between exercises and circuits respectively; and for ERT was in agreement with either ET or RT protocols, but the times of running and circuits were half of ET and RT. Results: ANCOVA showed that ET and ERT increased significantly (P< 0.05) vital capacity (VC), forced vital capacity (FVC), and forced expiratory flows to 25%-75%; ET, RT and ERT increased significantly (P< 0.05) maximum voluntary ventilation (MVV); and only ET increased significantly (P<0.05) peak expiratory flows (PEF); but ET, RT and ERT had no significant effect (P>0.05) on forced expiratory volume in one second (FEV1) and FEV1/FVC ratio. Conclusion: In conclusion, ET combined with RT (ERT) has greater effect on VC, FVC, FEF rating at25%-75%, and also on PEF except MVV, rather than RT, and just ET has greater effect rather than ERT. PMID:24250940

Restoration of Muscle Glycogen and Functional Capacity: Role of Post-Exercise Carbohydrate and Protein Co-Ingestion

PubMed Central

Alghannam, Abdullah F.; Betts, James A.

2018-01-01

The importance of post-exercise recovery nutrition has been well described in recent years, leading to its incorporation as an integral part of training regimes in both athletes and active individuals. Muscle glycogen depletion during an initial prolonged exercise bout is a main factor in the onset of fatigue and so the replenishment of glycogen stores may be important for recovery of functional capacity. Nevertheless, nutritional considerations for optimal short-term (3–6 h) recovery remain incompletely elucidated, particularly surrounding the precise amount of specific types of nutrients required. Current nutritional guidelines to maximise muscle glycogen availability within limited recovery are provided under the assumption that similar fatigue mechanisms (i.e., muscle glycogen depletion) are involved during a repeated exercise bout. Indeed, recent data support the notion that muscle glycogen availability is a determinant of subsequent endurance capacity following limited recovery. Thus, carbohydrate ingestion can be utilised to influence the restoration of endurance capacity following exhaustive exercise. One strategy with the potential to accelerate muscle glycogen resynthesis and/or functional capacity beyond merely ingesting adequate carbohydrate is the co-ingestion of added protein. While numerous studies have been instigated, a consensus that is related to the influence of carbohydrate-protein ingestion in maximising muscle glycogen during short-term recovery and repeated exercise capacity has not been established. When considered collectively, carbohydrate intake during limited recovery appears to primarily determine muscle glycogen resynthesis and repeated exercise capacity. Thus, when the goal is to optimise repeated exercise capacity following short-term recovery, ingesting carbohydrate at an amount of ≥1.2 g kg body mass−1·h−1 can maximise muscle glycogen repletion. The addition of protein to carbohydrate during post-exercise recovery may be beneficial under circumstances when carbohydrate ingestion is sub-optimal (≤0.8 g kg body mass−1·h−1) for effective restoration of muscle glycogen and repeated exercise capacity. PMID:29473893

Understanding the factors that effect maximal fat oxidation.

PubMed

Purdom, Troy; Kravitz, Len; Dokladny, Karol; Mermier, Christine

2018-01-01

Lipids as a fuel source for energy supply during submaximal exercise originate from subcutaneous adipose tissue derived fatty acids (FA), intramuscular triacylglycerides (IMTG), cholesterol and dietary fat. These sources of fat contribute to fatty acid oxidation (FAox) in various ways. The regulation and utilization of FAs in a maximal capacity occur primarily at exercise intensities between 45 and 65% VO 2max , is known as maximal fat oxidation (MFO), and is measured in g/min. Fatty acid oxidation occurs during submaximal exercise intensities, but is also complimentary to carbohydrate oxidation (CHOox). Due to limitations within FA transport across the cell and mitochondrial membranes, FAox is limited at higher exercise intensities. The point at which FAox reaches maximum and begins to decline is referred to as the crossover point. Exercise intensities that exceed the crossover point (~65% VO 2max ) utilize CHO as the predominant fuel source for energy supply. Training status, exercise intensity, exercise duration, sex differences, and nutrition have all been shown to affect cellular expression responsible for FAox rate. Each stimulus affects the process of FAox differently, resulting in specific adaptions that influence endurance exercise performance. Endurance training, specifically long duration (>2 h) facilitate adaptations that alter both the origin of FAs and FAox rate. Additionally, the influence of sex and nutrition on FAox are discussed. Finally, the role of FAox in the improvement of performance during endurance training is discussed.

[Evaluation of exercise capacity in pulmonary arterial hypertension].

PubMed

Demir, Rengin; Küçükoğlu, Mehmet Serdar

2010-12-01

Pulmonary arterial hypertension (PAH) is a life-threatening disease characterized by increased pulmonary vascular resistance that leads to right ventricular failure. The most common clinical features of PAH are dyspnea and exercise intolerance. Measurement of exercise capacity is of considerable importance for the assessment of disease severity as well as routine monitoring of disease. Maximal, symptom-limited, cardiopulmonary exercise test (CPET) is the gold standard for the evaluation of exercise capacity, whereby functions of several systems involved in exercise can be assessed, including cardiovascular, respiratory, and metabolic systems. However, in order to derive the most useful diagnostic information on physiologic limitations to exercise, CPET requires maximal effort of the patient, which can be difficult and risky for some severely ill patients. Moreover, it requires specific exercise equipment and measurement systems, and experienced and trained personnel. Thus, routine clinical use of CPET to assess exercise capacity in patients with PAH may not always be feasible. A practical and simple alternative to CPET to determine exercise capacity is the 6-minute walk test (6MWT). It is simple to perform, safe, and reproducible. In contrast to CPET, the 6MWT reflects a submaximal level of exertion that is more consistent with the effort required for daily physical activities. This review focuses on the role of CPET and 6MWT in patients with PAH.

Effects of lower extremity injuries on aerobic exercise capacity, anaerobic power, and knee isokinetic muscular function in high school soccer players.

PubMed

Ko, Kwang-Jun; Ha, Gi-Chul; Kim, Dong-Woo; Kang, Seol-Jung

2017-10-01

[Purpose] The study investigated the effects of lower extremity injuries on aerobic exercise capacity, anaerobic power, and knee isokinetic muscular function in high school soccer players. [Subjects and Methods] The study assessed U High School soccer players (n=40) in S area, South Korea, divided into 2 groups: a lower extremity injury group (n=16) comprising those with knee and ankle injuries and a control group (n=24) without injury. Aerobic exercise capacity, anaerobic power, and knee isokinetic muscular function were compared and analyzed. [Results] Regarding the aerobic exercise capacity test, significant differences were observed in maximal oxygen uptake and anaerobic threshold between both groups. For the anaerobic power test, no significant difference was observed in peak power and average power between the groups; however, a significant difference in fatigue index was noted. Regarding the knee isokinetic muscular test, no significant difference was noted in knee flexion, extension, and flexion/extension ratio between both groups. [Conclusion] Lower extremity injury was associated with reduced aerobic exercise capacity and a higher fatigue index with respect to anaerobic exercise capacity. Therefore, it seems necessary to establish post-injury training programs that improve aerobic and anaerobic exercise capacity for soccer players who experience lower extremity injury.

Impaired systemic oxygen extraction in treated exercise pulmonary hypertension: a new engine in an old car?

PubMed

Faria-Urbina, Mariana; Oliveira, Rudolf K F; Segrera, Sergio A; Lawler, Laurie; Waxman, Aaron B; Systrom, David M

2018-01-01

Ambrisentan in 22 patients with pulmonary hypertension diagnosed during exercise (ePH) improved pulmonary hemodynamics; however, there was only a trend toward increased maximum oxygen uptake (VO 2 max) secondary to decreased maximum exercise systemic oxygen extraction (Ca-vO 2 ). We speculate that improved pulmonary hemodynamics at maximum exercise "unmasked" a pre-existing skeletal muscle abnormality.

Benefits of aerobic exercise after stroke.

PubMed

Potempa, K; Braun, L T; Tinknell, T; Popovich, J

1996-05-01

The debilitating loss of function after a stroke has both primary and secondary effects on sensorimotor function. Primary effects include paresis, paralysis, spasticity, and sensory-perceptual dysfunction due to upper motor neuron damage. Secondary effects, contractures and disuse muscle atrophy, are also debilitating. This paper presents theoretical and empirical benefits of aerobic exercise after stroke, issues relevant to measuring peak capacity, exercise training protocols, and the clinical use of aerobic exercise in this patient population. A stroke, and resulting hemiparesis, produces physiological changes in muscle fibres and muscle metabolism during exercise. These changes, along with comorbid cardiovascular disease, must be considered when exercising stroke patients. While few studies have measured peak exercise capacity in hemiparetic populations, it has been consistently observed in these studies that stroke patients have a lower functional capacity than healthy populations. Hemiparetic patients have low peak exercise responses probably due to a reduced number of motor units available for recruitment during dynamic exercise, the reduced oxidative capacity of paretic muscle, and decreased overall endurance. Consequently, traditional methods to predict aerobic capacity are not appropriate for use with stroke patients. Endurance exercise training is increasingly recognised as an important component in rehabilitation. An average improvement in maximal oxygen consumption (VO2max) of 13.3% in stroke patients who participated in a 10-week aerobic exercise training programme has been reported compared with controls. This study underscored the potential benefits of aerobic exercise training in stroke patients. In this paper, advantages and disadvantages of exercise modalities are discussed in relation to stroke patients. Recommendations are presented to maximise physical performance and minimise potential cardiac risks during exercise.

Combination of exercise training and diet restriction normalizes limited exercise capacity and impaired skeletal muscle function in diet-induced diabetic mice.

PubMed

Suga, Tadashi; Kinugawa, Shintaro; Takada, Shingo; Kadoguchi, Tomoyasu; Fukushima, Arata; Homma, Tsuneaki; Masaki, Yoshihiro; Furihata, Takaaki; Takahashi, Masashige; Sobirin, Mochamad A; Ono, Taisuke; Hirabayashi, Kagami; Yokota, Takashi; Tanaka, Shinya; Okita, Koichi; Tsutsui, Hiroyuki

2014-01-01

Exercise training (EX) and diet restriction (DR) are essential for effective management of obesity and insulin resistance in diabetes mellitus. However, whether these interventions ameliorate the limited exercise capacity and impaired skeletal muscle function in diabetes patients remains unexplored. Therefore, we investigated the effects of EX and/or DR on exercise capacity and skeletal muscle function in diet-induced diabetic mice. Male C57BL/6J mice that were fed a high-fat diet (HFD) for 8 weeks were randomly assigned for an additional 4 weeks to 4 groups: control, EX, DR, and EX+DR. A lean group fed with a normal diet was also studied. Obesity and insulin resistance induced by a HFD were significantly but partially improved by EX or DR and completely reversed by EX+DR. Although exercise capacity decreased significantly with HFD compared with normal diet, it partially improved with EX and DR and completely reversed with EX+DR. In parallel, the impaired mitochondrial function and enhanced oxidative stress in the skeletal muscle caused by the HFD were normalized only by EX+DR. Although obesity and insulin resistance were completely reversed by DR with an insulin-sensitizing drug or a long-term intervention, the exercise capacity and skeletal muscle function could not be normalized. Therefore, improvement in impaired skeletal muscle function, rather than obesity and insulin resistance, may be an important therapeutic target for normalization of the limited exercise capacity in diabetes. In conclusion, a comprehensive lifestyle therapy of exercise and diet normalizes the limited exercise capacity and impaired muscle function in diabetes mellitus.

Effects of trimetazidine in nonischemic heart failure: a randomized study.

PubMed

Winter, José Luis; Castro, Pablo F; Quintana, Juan Carlos; Altamirano, Rodrigo; Enriquez, Andres; Verdejo, Hugo E; Jalil, Jorge E; Mellado, Rosemarie; Concepción, Roberto; Sepúlveda, Pablo; Rossel, Victor; Sepúlveda, Luis; Chiong, Mario; García, Lorena; Lavandero, Sergio

2014-03-01

Heart failure (HF) is associated with changes in myocardial metabolism that lead to impairment of contractile function. Trimetazidine (TMZ) modulates cardiac energetic efficiency and improves outcomes in ischemic heart disease. We evaluated the effects of TMZ on left ventricular ejection fraction (LVEF), cardiac metabolism, exercise capacity, O2 uptake, and quality of life in patients with nonischemic HF. Sixty patients with stable nonischemic HF under optimal medical therapy were included in this randomized double-blind study. Patients were randomized to TMZ (35 mg orally twice a day) or placebo for 6 months. LVEF, 6-minute walk test (6MWT), maximum O2 uptake in cardiopulmonary exercise test, different markers of metabolism, oxidative stress, and endothelial function, and quality of life were assessed at baseline and after TMZ treatment. Left ventricular peak glucose uptake was evaluated with the use of the maximum standardized uptake value (SUV) by 18-fluorodeoxyglucose positron emission tomography ((18)FDG-PET). Etiology was idiopathic in 85% and hypertensive in 15%. Both groups were similar in age, functional class, LVEF, and levels of N-terminal pro-B-type natriuretic peptide at baseline. After 6 months of TMZ treatment, no changes were observed in LVEF (31 ± 10% vs 34 ± 8%; P = .8), 6MWT (443 ± 25 m vs 506 ± 79 m; P = .03), maximum O2 uptake (19.1 ± 5.0 mL kg(-1) min(-1) vs 23.0 ± 7.2 mL kg(-1) min(-1); P = .11), functional class (percentages of patients in functional classes I/II/III/IV 10/3753/0 vs 7/40/50/3; P = .14), or quality of life (32 ± 26 points vs 24 ± 18 points; P = .25) in TMZ versus placebo, respectively. In the subgroup of patients evaluated with (18)FDG-PET, no significant differences were observed in SUV between both groups (7.0 ± 3.6 vs 8.2 ± 3.4 respectively; P = .47). In patients with nonischemic HF, the addition of TMZ to optimal medical treatment does not result in significant changes of LVEF, exercise capacity, O2 uptake, or quality of life. Copyright © 2014 Elsevier Inc. All rights reserved.

A structure-function analysis of the left ventricle

PubMed Central

Meyer, Leith C. R.; Fuller, Andrea; Haw, Anna; Mitchell, Duncan; Farrell, Anthony P.; Costello, Mary-Ann; Izwan, Adian; Badenhorst, Margaret; Maloney, Shane K.

2016-01-01

This study presents a structure-function analysis of the mammalian left ventricle and examines the performance of the cardiac capillary network, mitochondria, and myofibrils at rest and during simulated heavy exercise. Left ventricular external mechanical work rate was calculated from cardiac output and systemic mean arterial blood pressure in resting sheep (Ovis aries; n = 4) and goats (Capra hircus; n = 4) under mild sedation, followed by perfusion-fixation of the left ventricle and quantification of the cardiac capillary-tissue geometry and cardiomyocyte ultrastructure. The investigation was then extended to heavy exercise by increasing cardiac work according to published hemodynamics of sheep and goats performing sustained treadmill exercise. Left ventricular work rate averaged 0.017 W/cm3 of tissue at rest and was estimated to increase to ∼0.060 W/cm3 during heavy exercise. According to an oxygen transport model we applied to the left ventricular tissue, we predicted that oxygen consumption increases from 195 nmol O2·s−1·cm−3 of tissue at rest to ∼600 nmol O2·s−1·cm−3 during heavy exercise, which is within 90% of the oxygen demand rate and consistent with work remaining predominantly aerobic. Mitochondria represent 21-22% of cardiomyocyte volume and consume oxygen at a rate of 1,150 nmol O2·s−1·cm−3 of mitochondria at rest and ∼3,600 nmol O2·s−1·cm−3 during heavy exercise, which is within 80% of maximum in vitro rates and consistent with mitochondria operating near their functional limits. Myofibrils represent 65–66% of cardiomyocyte volume, and according to a Laplacian model of the left ventricular chamber, generate peak fiber tensions in the range of 50 to 70 kPa at rest and during heavy exercise, which is less than maximum tension of isolated cardiac tissue (120–140 kPa) and is explained by an apparent reserve capacity for tension development built into the left ventricle. PMID:27586835

Work, exercise, and space flight. 3: Exercise devices and protocols

NASA Technical Reports Server (NTRS)

Thornton, William

1989-01-01

Preservation of locomotor capacity by earth equivalent, exercise in space is the crucial component of inflight exercise. At this time the treadmill appears to be the only way possible to do this. Work is underway on appropriate hardware but this and a proposed protocol to reduce exercise time must be tested. Such exercise will preserve muscle, bone Ca(++) and cardiovascular-respiratory capacity. In addition, reasonable upper body exercise can be supplied by a new force generator/measurement system-optional exercise might include a rowing machine and bicycle ergometer. A subject centered monitoring-evaluation program will allow real time adjustments as required. Absolute protection for any astronaut will not be possible and those with hypertrophied capacities such as marathoners or weight lifters will suffer significant loss. However, the program described should return the crew to earth with adequate capacity of typical activity on earth including immediate ambulation and minimal recovery time and without permanent change. An understanding of the practical mechanics and biomechanics involved is essential to a solution of the problem.

[Follow-up of patients with good exercise capacity in stress test with myocardial single-photon emission computed tomography (SPECT)].

PubMed

González, Javiera; Prat, Hernán; Swett, Eduardo; Berrocal, Isabel; Fernández, René; Zhindon, Juan Pablo; Castro, Ariel; Massardo, Teresa

2015-11-01

The evaluation of coronary artery disease (CAD) can be performed with stress test and myocardial SPECT tomography. To assess the predictive value of myocardial SPECT using stress test for cardiovascular events in patients with good exercise capacity. We included 102 males aged 56 ± 10 years and 19 females aged 52 ± 10 years, all able to achieve 10 METs and ≥ 85% of the theoretical maximum heart rate and at least 8 min in their stress test with gated 99mTc-sestamibi SPECT. Eighty two percent of patients were followed clinically for 33 ± 17 months. Sixty seven percent of patients were studied for CAD screening and the rest for known disease assessment. Treadmill stress test was negative in 75.4%; 37% of patients with moderate to severe Duke Score presented ischemia. Normal myocardial perfusion SPECT was observed in 70.2%. Reversible defects appeared in 24.8% of cases, which were of moderate or severe degree (> 10% left ventricular extension) in 56.6%. Only seven cases had coronary events after the SPECT. Two major (myocardial infarction and emergency coronary revascularization) and 5 minor events (elective revascularization) ere observed in the follow-up. In a multivariate analysis, SPECT ischemia was the only statistically significant parameter that increased the probability of having a major or minor event. Nearly a quarter of our patients with good exercise capacity demonstrated reversible defects in their myocardial perfusion SPECT. In the intermediate-term follow-up, a low rate of cardiac events was observed, being the isotopic ischemia the only significant predictive parameter.

Effect of Baseline Exercise Capacity on Outcomes in Patients With Stable Coronary Heart Disease (A Post Hoc Analysis of the Clinical Outcomes Utilizing Revascularization and Aggressive Drug Evaluation Trial)

PubMed Central

Padala, Santosh K.; Sidhu, Mandeep S.; Hartigan, Pamela M.; Maron, David J.; Teo, Koon K.; Spertus, John A.; John Mancini, G.B.; Sedlis, Steven P.; Chaitman, Bernard R.; Heller, Gary V.; Weintraub, William S.; Boden, William E.

2017-01-01

The impact of baseline exercise capacity on clinical outcomes in patients with stable ischemic heart disease randomized to an initial strategy of optimal medical therapy (OMT) with or without percutaneous coronary intervention (PCI) in the Clinical Outcomes Utilizing Revascularization and Aggressive Drug Evaluation (COURAGE) trial has not been studied. A post hoc analysis was performed in 1,052 patients of COURAGE (PCI + OMT: n = 527, OMT: n = 525) who underwent exercise treadmill testing at baseline. Patients were categorized into 2 exercise capacity groups based on metabolic equivalents (METs) achieved during baseline exercise treadmill testing (<7 METs: n = 464, ≥7 METs: n = 588) and were followed for a median of 4.6 years. The primary composite end point of death or myocardial infarction was similar in the PCI + OMT group and the OMT group for patients with exercise capacity <7 METs (19.1% vs 16.1%, p = 0.31) and ≥7 METs (13.3% vs 10.3%, p = 0.27). After adjusting for baseline covariates, the hazard ratio (99% confidence interval) for the primary end point for the PCI + OMT group versus the OMT group was 1.42 (0.90 to 2.23, p = 0.05) and for the exercise capacity subgroups of ≥7 METs and <7 METs was 0.75 (0.46 to 1.22, p = 0.13). There was no statistically significant interaction between the original treatment arm allocation (PCI + OMT vs OMT) and baseline exercise capacity. In conclusion, there was no difference in the long-term clinical outcomes in patients with exercise capacity <7 METs compared with ≥7 METs, irrespective of whether they were assigned to initial PCI. Patients with exercise capacity <7 METs did not derive a proportionately greater clinical benefit from PCI + OMT compared with those patients who received OMT alone. Published by Elsevier Inc. (Am J Cardiol 2015;116:1509–1515) PMID:26410604

Supine Lower Body Negative Pressure Exercise Maintains Upright Exercise Capacity in Male Twins during 30 Days of Bed Rest

NASA Technical Reports Server (NTRS)

Lee, Stuart M. C.; Schneider, Suzanne M.; Boda, Wanda L.; Watenpaugh, Donald E.; Macias, Brandon R.; Meyer, R. Scott; Hargens, Alan R.

2006-01-01

Exercise capacity is reduced following both short and long duration exposures to microgravity. We have shown previously that supine lower body negative pressure with exercise (LBNP(sub ex) maintains upright exercise capacity in men after 5d and 15d bed rest, as a simulation of microgravity. We hypothesized that LBNP(sub ex) would protect upright exercise capacity (VO2pk) and sprint performance in eight sets of identical male twins during a 30-d bed rest. Twins within each set were randomly assigned to either a control group (CON) who performed no exercise or to an exercise group (EX) who performed a 40-min interval (40-80% pre-BR VO2pk) LBNP(sub ex) (55+/-4 mmHg) exercise protocol, plus 5 min of resting LBNP, 6 d/wk. LBNP produced footward force equivalent to 1.0- 1.2 times body weight. Pre- and post-bed rest, subjects completed an upright graded exercise test to volitional fatigue and sprint test of 30.5 m. After bed rest, VO2pk was maintained in the EX subjects (-3+/-3%), but was significantly decreased in the CON subjects (-24+/-4%). Sprint time also was increased in the CON subjects (24+/-8%), but maintained in the EX group (8+/-2%). The performance of a supine, interval exercise protocol with LBNP maintains upright exercise capacity and sprint performance during 30 d of bed rest. This exercise countermeasure protocol may help prevent microgravity-induced deconditioning during long duration space flight.

Exercise training guidelines for the elderly.

PubMed

Evans, W J

1999-01-01

The capacity of older men and women to adapt to increased levels of physical activity is preserved, even in the most elderly. Aerobic exercise results in improvements in functional capacity and reduced risk of developing Type II diabetes in the elderly. High-intensity resistance training (above 60% of the one repetition maximum) has been demonstrated to cause large increases in strength in the elderly. In addition, resistance training result in significant increases in muscle size in elderly men and women. Resistance training has also been shown to significantly increase energy requirements and insulin action of the elderly. We have recently demonstrated that resistance training has a positive effect on multiple risk factors for osteoporotic fracture in previously sedentary postmenopausal women. Because the sedentary lifestyle of a long-term care facility may exacerbate losses of muscle function, we have applied this same training program to frail, institutionalized elderly men and women. In a population of 100 nursing home residents, a randomly assigned high-intensity strength-training program resulted in significant gains in strength and functional status. In addition, spontaneous activity, measured by activity monitors, increased significantly in those participating in the exercise program whereas there was no change in the sedentary control group. Before the strength training intervention, the relationship of whole body potassium and leg strength was seen to be relatively weak (r2 = 0.29, P < 0.001), indicating that in the very old, muscle mass is an important but not the only determining factor of functional status. Thus, exercise may minimize or reverse the syndrome of physical frailty, which is so prevalent among the most elderly. Because of their low functional status and high incidence of chronic disease, there is no segment of the population that can benefit more from exercise than the elderly.

One year of high-intensity interval training improves exercise capacity, but not left ventricular function in stable heart transplant recipients: a randomised controlled trial.

PubMed

Rustad, Lene A; Nytrøen, Kari; Amundsen, Brage H; Gullestad, Lars; Aakhus, Svend

2014-02-01

Heart transplant recipients have lower exercise capacity and impaired cardiac function compared with the normal population. High-intensity interval training (HIIT) improves exercise capacity and cardiac function in patients with heart failure and hypertension, but the effect on cardiac function in stable heart transplant recipients is not known. Thus, we investigated whether HIIT improved cardiac function and exercise capacity in stable heart transplant recipients by use of comprehensive rest- and exercise-echocardiography and cardiopulmonary exercise testing. Fifty-two clinically stable heart transplant recipients were randomised either to HIIT (4 × 4 minutes at 85-95% of peak heart rate three times per week for eight weeks) or to control. Three such eight-week periods were distributed throughout one year. Echocardiography (rest and submaximal exercise) and cardiopulmonary exercise testing were performed at baseline and follow-up. One year of HIIT increased VO 2peak from 27.7 ± 5.5 at baseline to 30.9 ± 5.0 ml/kg/min at follow-up, while the control group remained unchanged (28.5 ± 7.0 vs. 28.0 ± 6.7 ml/kg per min, p < 0.001 for difference between the groups). Systolic and diastolic left ventricular functions at rest and during exercise were generally unchanged by HIIT. Whereas HIIT is feasible in heart transplant recipients and effectively improves exercise capacity, it does not alter cardiac systolic and diastolic function significantly. Thus, the observed augmentation in exercise capacity is best explained by extra-cardiac adaptive mechanisms.

Effects of 1-Methylnicotinamide (MNA) on Exercise Capacity and Endothelial Response in Diabetic Mice.

PubMed

Przyborowski, Kamil; Wojewoda, Marta; Sitek, Barbara; Zakrzewska, Agnieszka; Kij, Agnieszka; Wandzel, Krystyna; Zoladz, Jerzy Andrzej; Chlopicki, Stefan

2015-01-01

1-Methylnicotinamide (MNA), which was initially considered to be a biologically inactive endogenous metabolite of nicotinamide, has emerged as an anti-thrombotic and anti-inflammatory agent with the capacity to release prostacyclin (PGI2). In the present study, we characterized the effects of MNA on exercise capacity and the endothelial response to exercise in diabetic mice. Eight-week-old db/db mice were untreated or treated with MNA for 4 weeks (100 mg·kg-1), and their exercise capacity as well as NO- and PGI2-dependent response to endurance running were subsequently assessed. MNA treatment of db/db mice resulted in four-fold and three-fold elevation of urine concentrations of MNA and its metabolites (Met-2PY + Met-4PY), respectively (P<0.01), but did not affect HbA1c concentration, fasting glucose concentration or lipid profile. However, insulin sensitivity was improved (P<0.01). In MNA-treated db/db mice, the time to fatigue for endurance exercise was significantly prolonged (P<0.05). Post-exercise Δ6-keto-PGF1α (difference between mean concentration in the sedentary and exercised groups) tended to increase, and post-exercise leukocytosis was substantially reduced in MNA-treated animals. In turn, the post-exercise fall in plasma concentration of nitrate was not affected by MNA. In conclusion, we demonstrated for the first time that MNA improves endurance exercise capacity in mice with diabetes, and may also decrease the cardiovascular risk of exercise.

Impaired left ventricular systolic function reserve limits cardiac output and exercise capacity in HFpEF patients due to systemic hypertension.

PubMed

Henein, Michael; Mörner, Stellan; Lindmark, Krister; Lindqvist, Per

2013-09-30

Heart failure (HF) patients with preserved left ventricular (LV) ejection fraction (EF) (HFpEF) due to systemic hypertension (SHT) are known to have limited exercise tolerance. Despite having normal EF at rest, we hypothesize that these patients have abnormal systolic function reserve limiting their exercise capacity. Seventeen patients with SHT (mean age 68 ± 9 years) but no valve disease and 14 healthy individuals (mean age of 65 ± 10 years) underwent resting and peak exercise echocardiography using conventional, tissue Doppler and speckle tracking techniques. The differences between resting and peak exercise values were also analyzed (Δ). Exercise capacity was determined as the workload divided by body surface area. Resting values for left atrial (LA) volume/BSA (r=-0.66, p<0.001) and global longitudinal strain rate (GLSR) in early (e) and late (a) diastole (r=0.47 and 0.46, p<0.05 for both) correlated with exercise capacity. LVEF increased during exercise in normals (mean Δ EF=10 ± 8%) but failed to do so in patients (mean Δ EF=0.6 ± 9%, p<0.001 between groups). LV GLSR during systole (s) also failed to increase with exercise in patients, to the same extent as it did in normals (0.2 ± 0.2 vs. 0.6 ± 0.3 1/s, p<0.001). The difference between rest and exercise (Δ) in LV lateral wall systolic velocity from tissue Doppler (s') (0.71, p<0.001), Δ in cardiac output (r=0.60, p<0.001) and Δ GLSRs (r=0.48, p<0.05) all correlated with exercise capacity independent of changes in heart rate. HFpEF patients with hypertensive LV disease have significantly limited exercise capacity which is related to left atrial enlargement as well as compromised LV systolic function at the time of the symptoms. The limited myocardial systolic function reserve seems to be underlying important explanation for their limited exercise capacity. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Oxygen consumption during exercise in a heated pool.

PubMed

Kirby, R L; Sacamano, J T; Balch, D E; Kriellaars, D J

1984-01-01

The heated hydrotherapy pool is a common exercise site for patients with painful musculoskeletal conditions. Oxygen consumption of swimming is 87 to 89% of maximum in postmyocardial infarction patients according to one recent investigation. We studied 13 able-bodied subjects to test the hypothesis that enough energy could be expended during various forms of hydrotherapy to produce both an aerobic training effect and a risk to patients with coronary artery disease. Oxygen consumption (VO2) was measured in six settings: resting supine; resting seated shoulder deep in the pool (36C); walking at comfortable speed in chest-deep water; running at the fastest speed possible in chest-deep water; using hand paddles; and running in place at shoulder depth. The mean VO2 expressed in ml/kg/min (and metabolic equivalents) were 4.91 (1.00), 4.93 (1.02), 9.34 (2.01), 27.79 (6.23), 18.25 (4.30) and 29.11 (7.09) respectively, suggesting that the more vigorous exercises stress aerobic capacity heavily but not excessively.

[Effects of TES program on exercise capacity, self-efficacy and patient compliance in patients with myocardial infarction].

PubMed

Choo, Jina; Kim, Ja-Mae; Hong, Kyung-Pyo

2003-12-01

This study aimed to develop a TES program to improve exercise capacity to promote patient compliance to the prescribed exercise, and to test the feasibility of the program. The 8-week TES program consisted of three components : exercise training, self-efficacy enhancement and social support. Using the matching of gender, age, and the left ventricular ejection fraction, thirty one subjects were consecutively assigned to either TES group (n=15, 52+7 years) or Control group (n=16, 58+11 years) 3 weeks after MI. With the exception of exercise compliance (only after the TES program), the exercise capacity and exercise self-efficacy were both measured both before and after the 8-week TES program. The VO2peak (p=.043), anaerobic threshold (p=.023) and exercise duration (p=.015) improved in TES group compared to Control group after 8 weeks. The cardiac exercise self-efficacy (p=.036) was significantly higher in TES group than Control group. There was a significant increase of exercise compliance(p=.005) in TES group compared to Control group. The 8-week TES program improved the exercise capacity, exercise self-efficacy and exercise compliance. A appropriately implemented TES program in cardiovascular nursing practice may promote healthy behavioral modification and, therefore, contributing to reduce the risk of mortality and morbidity in MI patients.

Complete low-intensity endurance training programme in haemodialysis patients: improving the care of renal patients.

PubMed

Esteve Simó, Vicent; Junqué, Anna; Fulquet, Miquel; Duarte, Verónica; Saurina, Anna; Pou, Mónica; Moreno, Fátima; Carneiro, Jose; Ramírez de Arellano, Manel

2014-01-01

Patients on haemodialysis (HD) have a decreased physical and functional capacity. Several studies have reported the beneficial effects of exercise on the physical, functional and psychological functioning of HD patients. Despite these results, exercise programmes on HD are not commonplace. To analyse the effect of an intradialysis endurance training programme on muscular strength and functional capacity in our HD patients. A 6-month single-centre prospective study. HD patients were non-randomly assigned to an exercise group (group E) or a control group (group C). Exercise training included complete endurance training using balls, weights and elastic bands in the first 2 h of an HD session; group C received standard HD care. Analysed data: (1) biochemical parameters; (2) biceps and quadriceps muscle tone, maximum quadriceps length strength (MQLS) and dominant hand grip (HG); (3) functional capacity tests: sit-to-stand-to-sit (STS10) and 6-min walking test (6MWT). Forty patients were included, 55% were men; their mean age was 68.4 years; the patients were 61.6 months on HD; 16 patients were in group E and 24 in group C. In group E, muscular strength showed a significant improvement in MQLS (15.6 ± 10.7 vs. 17.7 ± 12.5 kg, p < 0.05) and HG (22.1 ± 13.2 vs. 24.1 ± 15.8 kg, p < 0.05) at the end of the programme, while a global decrease was reported in group C (MQLS 20.9 ± 9.3 vs. 16.2 ± 8.4 kg, p < 0.05; HG 25.1 ± 10.3 vs. 24.1 ± 11.1 kg). 6MWT significantly improved in group E (20%, 293.1 vs. 368 m, p < 0.001) and decreased in group C (10%, 350 vs. 315 m, p < 0.004). At the end of the programme, STS10 time was reduced in group E (2.1 ± 18.5 vs. 28.7 ± 20.6 s), while it rose in group C (31.5 ± 17.9 vs. 36.4 ± 19.8 s), though significant differences were not found. (1) The intradialysis training programme improved muscular strength and functional capacity in our HD patients. (2) These results support the benefits of exercise training for HD patients. (3) Nephrologists should consider exercise training as a standard practice for the care of HD patients. © 2014 S. Karger AG, Basel.

Effects of lumbopelvic sling and abdominal drawing-in exercises on lung capacity in healthy adults.

PubMed

Kim, Myoung-Kwon; Cha, Hyun-Gyu; Shin, Young-Jun

2016-08-01

[Purpose] To examine the effects of lumbopelvic sling and abdominal drawing-in exercises on the lung capacities of healthy subjects. [Subjects and Methods] Twenty-nine healthy subjects with no orthopedic history of the back were recruited. Subjects were randomly assigned to a experimental group and control group. Subjects were allocated to one of two groups; an experimental group that underwent lumbopelvic sling and abdominal drawing-in exercises and a control group that underwent treadmill and abdominal drawing-in exercises. Lung capacities were evaluated 4 weeks after exercises. [Results] The experimental group showed significant increments in EV, ERV, IRV, VT vs. pre-intervention results, and the control group showed significant increments in the EVC and IRV. Significant intergroup differences were observed in terms of post-training gains in EVC, IRV, and VT. [Conclusion] Combined application of lumbopelvic sling and abdominal drawing-in exercises were found to have a positive effect on lung capacity.

New insights into the benefits of exercise for muscle health in patients with idiopathic inflammatory myositis.

PubMed

Alemo Munters, Li; Alexanderson, Helene; Crofford, Leslie J; Lundberg, Ingrid E

2014-07-01

With recommended treatment, a majority with idiopathic inflammatory myopathy (IIM) develop muscle impairment and poor health. Beneficial effects of exercise have been reported on muscle performance, aerobic capacity and health in chronic polymyositis and dermatomyositis and to some extent in active disease and inclusion body myositis (IBM). Importantly, randomized controlled trials (RCTs) indicate that improved health and decreased clinical disease activity could be mediated through increased aerobic capacity. Recently, reports seeking mechanisms underlying effects of exercise in skeletal muscle indicate increased aerobic capacity (i.e. increased mitochondrial capacity and capillary density, reduced lactate levels), activation of genes in aerobic phenotype and muscle growth programs, and down regulation in genes related to inflammation. Altogether, exercise contributes to both systemic and within-muscle adaptations demonstrating that exercise is fundamental to improve muscle performance and health in IIM. There is a need for RCTs to study effects of exercise in active disease and IBM.

A shirt containing multistage phase change material and active cooling components was associated with increased exercise capacity in a hot, humid environment.

PubMed

McFarlin, Brian K; Henning, Andrea L; Venable, Adam S; Williams, Randall R; Best Sampson, Jill N

2016-08-01

Recent advances in clothing design include the incorporation of phase change materials (PCM) and other active cooling components (ACC) to provide better body heat dissipation. The purpose of this study was to determine the effect of wearing a shirt containing multistage PCM/ACC on exercise capacity at low (5.0), moderate-high (7.5) and extreme (9.0) levels of the physiological strain index (PSI). Fourteen individuals tested two shirts (control vs. cooling) during 45-min of interval running in a hot, humid (35 ± 1 °C; 55 ± 6% RH) environment. The cooling shirt resulted in an 8% improvement in exercise capacity at a PSI of 7.5 (p < 0.05). The observed increase in exercise capacity would likely translate to a significant improvement in exercise performance. More research is needed to determine a best practice approach for the use of cooling clothing as a counter to exercise-induced heat exposure. Practitioner Summary: In this report, we demonstrate that when forced to exercise in a hot, humid environment, an individual's exercise capacity may increase by as much as 8% when wearing a shirt composed of multistage phase change material and active cooling components.

Exhaustive submaximal endurance and resistance exercises induce temporary immunosuppression via physical and oxidative stress

PubMed Central

Jin, Chan-Ho; Paik, Il-Young; Kwak, Yi-Sub; Jee, Yong-Seok; Kim, Joo-Young

2015-01-01

Regular running and strength training are the best ways to improve aerobic capacity and develop the size of skeletal muscles. However, uncontrolled physical activities can often lead to an undertraining or over-training syndrome. In particular, overtraining causes persistent fatigue and reduces physical performance due to changes in the various physiological and immunological factors. In this study, we gave an exhaustive submaximal endurance or resistance exercise to participants and investigated the relationship between physical stress (cortisol level in blood), oxidative stress (intracellular ROS accumulation), and adaptive immune response (CD4:CD8 ratio). Materials and Methods Ten male volunteers were recruited, and performed a submaximal endurance or resistance exercise with 85% of VO2max or 1-repetition maximum until exhaustion. Blood samples were collected at rest, and at 0 and 30 min after the exercise. Cortisol levels, oxidative stress, and immune cell phenotypes in peripheral blood were evaluated. Cortisol levels in the sera increased after the exhaustive endurance and resistance exercises and such increments were maintained through the recovery. Intra-cellular ROS levels also increased after the exhaustive endurance and resistance exercises. The ratio of CD4+ T cells to CD8+ T cells after each type of submaximal exercise decreased compared with that at the resting stage, and returned to the resting level at 30 min after the exercise. In this study, an exhaustive endurance or a resistance exercise with submaximal intensity caused excessive physical stress, intra-cellular oxidative stress, and post-exercise immunosuppression. This result suggests that excessive physical stress induced temporary immune dysfunction via physical and oxidative stress. PMID:26331134

Melatonin Supplementation Ameliorates Energy Charge and Oxidative Stress Induced by Acute Exercise in Rat Heart Tissue

PubMed Central

Cimen, Behzat; Uz, Ali; Cetin, Ihsan; Cimen, Leyla; Cetin, Aysun

2017-01-01

Background Regular physical exercises may help people to be more resistant to everyday problems; however, how acute and intense exercises affect the heart tissues functioning with maximum capacity and how melatonin changes the effect of acute and intense exercises are still not obvious. We aimed to comprehend whether melatonin intravenous injection supports the oxidative/antioxidative conditions and energy charge in heart tissues of rats exposed to acute swimming exercise. Methods Thirty Wistar-albino male rats were categorized into 3 groups with equal number of subjects. Control group performed no application, and acute intensive swimming exercise group were subjected to acute intensive swimming exercise for 30 minutes, and melatonin group were applied 25 mg/kg single dose melatonin administration prior to 30 minutes acute intensive swimming exercise. The levels of malondialdehyde (MDA), and superoxide dismutase, catalase and glutathione peroxidase activities were measured by spectrophotometric method; and the levels of 3-nitrotyrosine (3-NT) and energy charge were determined by a high performance liquid chromatography. Results Tissue MDA and 3-NT levels of the acute intensive exercise group were found to be higher than the control group. It was also found that the melatonin administration increased the energy charge and antioxidant activities, while decreased tissue MDA and 3-NT levels in heart tissues. Our results provide evidence for melatonin that can exert potent protective effects on oxidative stress and energy charge for heart tissues in acute swimming exercise. Conclusions These findings suggest that the direct beneficial effects of melatonin could be potentially applied on prevention of oxidative stress and energy deficit. PMID:28959107

Cardiovascular rehabilitation soon after stroke using feedback-controlled robotics-assisted treadmill exercise: study protocol of a randomised controlled pilot trial.

PubMed

Stoller, Oliver; de Bruin, Eling D; Schuster-Amft, Corina; Schindelholz, Matthias; de Bie, Rob A; Hunt, Kenneth J

2013-09-22

After experiencing a stroke, most individuals also suffer from cardiac disease, are immobile and thus have low endurance for exercise. Aerobic capacity is seriously reduced in these individuals and does not reach reasonable levels after conventional rehabilitation programmes. Cardiovascular exercise is beneficial for improvement of aerobic capacity in mild to moderate stroke. However, less is known about its impact on aerobic capacity, motor recovery, and quality-of-life in severely impaired individuals. The aim of this pilot study is to explore the clinical efficacy and feasibility of cardiovascular exercise with regard to aerobic capacity, motor recovery, and quality-of-life using feedback-controlled robotics-assisted treadmill exercise in non-ambulatory individuals soon after experiencing a stroke. This will be a single-centred single blind, randomised control trial with a pre-post intervention design. Subjects will be recruited early after their first stroke (≤20 weeks) at a neurological rehabilitation clinic and will be randomly allocated to an inpatient cardiovascular exercise programme that uses feedback-controlled robotics-assisted treadmill exercise (experimental) or to conventional robotics-assisted treadmill exercise (control). Intervention duration depends on the duration of each subject's inpatient rehabilitation period. Aerobic capacity, as the primary outcome measure, will be assessed using feedback-controlled robotics-assisted treadmill-based cardiopulmonary exercise testing. Secondary outcome measures will include gait speed, walking endurance, standing function, and quality-of-life. Outcome assessment will be conducted at baseline, after each 4-week intervention period, and before clinical discharge. Ethical approval has been obtained. Whether cardiovascular exercise in non-ambulatory individuals early after stroke has an impact on aerobic capacity, motor recovery, and quality-of-life is not yet known. Feedback-controlled robotics-assisted treadmill exercise is a relatively recent intervention method and might be used to train and evaluate aerobic capacity in this population. The present pilot trial is expected to provide new insights into the implementation of early cardiovascular exercise for individuals with severe motor impairment. The findings of this study may guide future research to explore the effects of early cardiovascular activation after severe neurological events. This trial is registered with the Clinical Trials.gov Registry (NCT01679600).

Effects of a pulmonary rehabilitation program on physical capacity, peripheral muscle function and inflammatory markers in asthmatic children and adolescents: study protocol for a randomized controlled trial.

PubMed

Reimberg, Mariana Mazzuca; Castro, Rejane Agnelo Silva; Selman, Jessyca Pachi Rodrigues; Meneses, Aline Santos; Politti, Fabiano; Mallozi, Márcia Carvalho; Wandalsen, Gustavo Falbo; Solé, Dirceu; De Angelis, Kátia; Dal Corso, Simone; Lanza, Fernanda Cordoba

2015-08-13

Individuals with chronic lung disease are more susceptible to present reduction in exercise tolerance and muscles strength not only due to pulmonary limitations but also due systemic repercussions of the pulmonary disease. The aim of this study is to assess the physical capacity, peripheral muscle function, physical activity in daily life, and the inflammatory markers in children and adolescents with asthma after pulmonary rehabilitation program. This is a study protocol of randomized controlled trial in asthmatic patients between 6 to 18 years old. The assessments will be conducted in three different days and will be performed at the beginning and at the end of the protocol. First visit: quality of life questionnaire, asthma control questionnaire, pre- and post-bronchodilator spirometry (400 μcg salbutamol), inflammatory assessment (blood collection), and cardiopulmonary exercise test on a cycle ergometer to determine aerobic capacity. Second visit: assessment of strength and endurance of the quadriceps femoris and biceps brachii muscles with concomitant electromyography to assess peripheral muscle strength. Third visit: incremental shuttle walk test (ISWT) and accelerometer to evaluate functional capacity and physical activity in daily life during 7 days. Then, the volunteers will be randomized to receive pulmonary rehabilitation program (intervention group) or chest physiotherapy + stretching exercises (control group). Both groups will have a supervised session, twice a week, each session will have 60 minutes duration, with minimum interval of 24 hours, for a period of 8 weeks. Intervention group: aerobic training (35 minutes) intensity between 60 to 80 % of the maximum workload of cardiopulmonary exercise testing or of ISWT; strength muscle training will be applied to the quadriceps femoris, biceps brachii and deltoid muscles (intensity: 40 to 70 % of maximal repetition, 3 x 8 repetition); finally the oral high-frequency oscillation device (Flutter®) will be used for 5 minutes. The control group: oral high-frequency oscillation device (Flutter®) for 10 minutes followed by the stretching of upper and lower limbs for 40 minutes. It is expected to observe the improvement in aerobic capacity, physical activity in daily life, muscle strength and quality of life of patients in the intervention group, and reduction in inflammatory markers. NCT02383069. Data of registration: 03/03/2015.

Exercise training programs to improve hand rim wheelchair propulsion capacity: a systematic review.

PubMed

Zwinkels, Maremka; Verschuren, Olaf; Janssen, Thomas Wj; Ketelaar, Marjolijn; Takken, Tim

2014-09-01

An adequate wheelchair propulsion capacity is required to perform daily life activities. Exercise training may be effective to gain or improve wheelchair propulsion capacity. This review investigates whether different types of exercise training programs are effective in improving wheelchair propulsion capacity. PubMed and EMBASE databases were searched from their respective inceptions in October 2013. Exercise training studies with at least one outcome measure regarding wheelchair propulsion capacity were included. In this study wheelchair propulsion capacity includes four parameters to reflect functional wheelchair propulsion: cardio-respiratory fitness (aerobic capacity), anaerobic capacity, muscular fitness and mechanical efficiency. Articles were not selected on diagnosis, training type or mode. Studies were divided into four training types: interval, endurance, strength, and mixed training. Methodological quality was rated with the PEDro scale, and the level of evidence was determined. The 21 included studies represented 249 individuals with spinal-cord injury (50%), various diagnoses like spina bifida (4%), cerebral palsy (2%), traumatic injury, (3%) and able-bodied participants (38%). All interval training studies found a significant improvement of 18-64% in wheelchair propulsion capacity. Three out of five endurance training studies reported significant effectiveness. Methodological quality was generally poor and there were only two randomised controlled trials. Exercise training programs seem to be effective in improving wheelchair propulsion capacity. However, there is remarkably little research, particularly for individuals who do not have spinal-cord injury. © The Author(s) 2014.

Exercise-Induced Pulmonary Hypertension: Translating Pathophysiological Concepts Into Clinical Practice.

PubMed

Naeije, Robert; Saggar, Rajeev; Badesch, David; Rajagopalan, Sanjay; Gargani, Luna; Rischard, Franz; Ferrara, Francesco; Marra, Alberto M; D' Alto, Michele; Bull, Todd M; Saggar, Rajan; Grünig, Ekkehard; Bossone, Eduardo

2018-01-31

Exercise stress testing of the pulmonary circulation for the diagnosis of latent or early-stage pulmonary hypertension (PH) is gaining acceptance. There is emerging consensus to define exercise-induced PH by a mean pulmonary artery pressure > 30 mm Hg at a cardiac output < 10 L/min and a total pulmonary vascular resistance> 3 Wood units at maximum exercise, in the absence of PH at rest. Exercise-induced PH has been reported in association with a bone morphogenetic receptor-2 gene mutation, in systemic sclerosis, in left heart conditions, in chronic lung diseases, and in chronic pulmonary thromboembolism. Exercise-induced PH is a cause of decreased exercise capacity, may precede the development of manifest PH in a proportion of patients, and is associated with a decreased life expectancy. Exercise stress testing of the pulmonary circulation has to be dynamic and rely on measurements of the components of the pulmonary vascular equation during, not after exercise. Noninvasive imaging measurements may be sufficiently accurate in experienced hands, but suffer from lack of precision, so that invasive measurements are required for individual decision-making. Exercise-induced PH is caused either by pulmonary vasoconstriction, pulmonary vascular remodeling, or by increased upstream transmission of pulmonary venous pressure. This differential diagnosis is clinical. Left heart disease as a cause of exercise-induced PH can be further ascertained by a pulmonary artery wedge pressure above or below 20 mm Hg at a cardiac output < 10 L/min or a pulmonary artery wedge pressure-flow relationship above or below 2 mm Hg/L/min during exercise. Copyright © 2018 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.

Comparison of two progressive treadmill tests in patients with peripheral arterial disease.

PubMed

Riebe, D; Patterson, R B; Braun, C M

2001-11-01

In a vascular rehabilitation program, 28% of our frail elderly patients are unable to be tested with traditional progressive exercise protocols at program entry due to the high (2.0 miles/h or 3.2 km/h) initial treadmill speeds. The purpose of this investigation was to compare a new progressive treadmill protocol which has a reduced initial speed (1.0 mile/h or 1.6 km/h) to an established protocol performed at 2.0 miles/h (3.2 km/h) to determine the comparability and reproducibility of the new protocol. Eleven patients with arterial claudication performed three symptom-limited exercise tests in random order. Two tests used the new protocol while the remaining trial used the established protocol. Claudication pain was measured using a 5-point scale. Oxygen consumption, heart rate, minute ventilation, respiratory exchange ratio and blood pressure at peak exercise were similar among the three trials. There were strong intraclass correlations for peak oxygen consumption (r = 0.97), onset of claudication (r = 0.96) and maximum walking time (r = 0.98) between the two trials using the new protocol. There was also a significant correlation between the new protocol and the established protocol for peak oxygen consumption (r = 0.90) and maximum walking time (r = 0.89). The new progressive treadmill protocol represents a valid, reliable protocol for patients with arterial claudication. This protocol may be useful for testing patients with a low functional capacity so that clinically appropriate exercise prescriptions can be established and the efficacy of treatments can be determined.

Utilization of the graded universal testing system to increase the efficiency for assessing aerobic and anaerobic capacity

NASA Technical Reports Server (NTRS)

Rodgers, Sandra L.

1992-01-01

The in-flight exercise test performed by cosmonauts as part of the Russian Exercise Countermeasure Program is limited to 5 minutes due to communication restrictions. During a recent graded exercise test on a U.S. Shuttle flight, the test was terminated early due to an upcoming loss of signal (LOS) with the ground. This exercise test was a traditional test where the subject's exercise capacity dictates the length of the test. For example, one crew member may take 15 minutes to complete the test, while another may take 18 minutes. The traditional exercise test limits the flight schedulers to large blocks of space flight time in order to provide medical and research personnel information on the fitness capacity (maximal oxygen uptake: VO2max) of crew members during flight. A graded exercise test that would take a finite amount of time and a set preparation and recovery time would ease this problem by allowing flight schedulers to plan exercise tests in advance of LOS. The Graded Universal Testing System (GUTS) was designed to meet this goal. Fitness testing of astronauts before and after flight provides pertinent data on many variables. The Detailed Supplemental Objective (DSO608) protocol (6) is one of the graded exercise tests (GXT) currently used in astronaut testing before and after flight. Test times for this protocol have lasted from 11 to 18 minutes. Anaerobic capacity is an important variable that is currently not being evaluated before and after flight. Recent reports (1,2,5) from the literature have suggested that the oxygen deficit at supramaximal exercise is a measure of anaerobic capacity. We postulated that the oxygen deficit at maximal exercise would be an indication of anaerobic capacity. If this postulate can be accepted, then the efficiency of acquiring data from a graded exercise test would increase at least twofold. To examine this hypothesis anaerobic capacity was measured using a modified treadmill test (3,4) designed to exhaust the anaerobic systems in approximately 45 to 75 seconds. Lactate concentration in the blood was analyzed after all tests, since lactate is the end-product of anaerobic energy production. Therefore, the peak lactate response is an additional indication of anaerobic capacity. A preliminary comparison of the GUTS and the DSO608 suggests that the GUTS protocol would increase the efficiency of VO2max testing of astronauts before and after flight. Results for anaerobic capacity have not been tabulated.

Patient-Reported Dyspnea Correlates Poorly with Aerobic Exercise Capacity Measured During Cardiopulmonary Exercise Testing.

PubMed

Gaspard, Dany; Kass, Jonathan; Akers, Stephen; Hunter, Krystal; Pratter, Melvin

2017-10-01

Patient-reported dyspnea plays a central role in assessing cardiopulmonary disease. There is little evidence, however, that dyspnea correlates with objective exercise capacity measurements. If the correlation is poor, dyspnea as a proxy for objective assessment may be misleading. To compare patient's perception of dyspnea with maximum oxygen uptake (MaxVO2) during cardiopulmonary exercise testing (CPET). Fifty patients undergoing CPET for dyspnea evaluation were studied prospectively. Dyspnea assessment was measured by a metabolic equivalent of task (METs) table, Mahler Dyspnea Index, Borg Index, number of blocks walked, and flights of stairs climbed before stopping due to dyspnea. These descriptors were compared to MaxVO2. MaxVO2 showed low correlation with METs table (r = 0.388, p = 0.005) and no correlation with Mahler Index (r = 0.24, p = 0.093), Borg Index (r = -0.017, p = 0.905), number of blocks walked (r = 0.266, p = 0.077) or flights of stairs climbed (r = 0.188, p = 0.217). When adjusted for weight (maxVO2/kg), there was significant correlation between MaxVO2 and METs table (r = 0.711, p < 0.001), moderate correlation with blocks walked (r = 0.614, p < 0.001), and low correlation with Mahler Index (r = 0.488 p = 0.001), Borg Index (r = -0.333 p = 0.036), and flights of stairs (r = 0.457 p = 0.004). Subgroup analysis showed worse correlation when patients with normal CPET were excluded (12/50 excluded). Patients with BMI < 30 had no correlation between Max VO2 and the assessment methods, while patients with BMI > 30 had moderate correlation between MaxVO2 and METs table (r = 0.568, p = 0.002). Patient-reported dyspnea correlates poorly with MaxVO2 and fails to predict exercise capacity. Reliance on reported dyspnea may result in suboptimal categorization of cardiopulmonary disease severity.

Mechanical ventilatory constraints during incremental cycle exercise in human pregnancy: implications for respiratory sensation

PubMed Central

Jensen, Dennis; Webb, Katherine A; Davies, Gregory A L; O'Donnell, Denis E

2008-01-01

The aim of this study was to identify the physiological mechanisms of exertional respiratory discomfort (breathlessness) in pregnancy by comparing ventilatory (breathing pattern, airway function, operating lung volumes, oesophageal pressure (Poes)-derived indices of respiratory mechanics) and perceptual (breathlessness intensity) responses to incremental cycle exercise in 15 young, healthy women in the third trimester (TM3; between 34 and 38 weeks gestation) and again 4–5 months postpartum (PP). During pregnancy, resting inspiratory capacity (IC) increased (P < 0.01) and end-expiratory lung volume decreased (P < 0.001), with no associated change in total lung capacity (TLC) or static respiratory muscle strength. This permitted greater tidal volume (VT) expansion throughout exercise in TM3, while preserving the relationship between contractile respiratory muscle effort (tidal Poes swing expressed as a percentage of maximum inspiratory pressure (PImax)) and thoracic volume displacement (VT expressed as a percentage of vital capacity) and between breathlessness and ventilation (V̇E). At the highest equivalent work rate (HEWR = 128 ± 5 W) in TM3 compared with PP: V̇E, tidal Poes/PImax and breathlessness intensity ratings increased by 10.2 l min−1 (P < 0.001), 8.8%PImax (P < 0.05) and 0.9 Borg units (P < 0.05), respectively. Pulmonary resistance was not increased at rest or during exercise at the HEWR in TM3, despite marked increases in mean tidal inspiratory and expiratory flow rates, suggesting increased bronchodilatation. Dynamic mechanical constraints on VT expansion (P < 0.05) with associated increased breathlessness intensity ratings (P < 0.05) were observed near peak exercise in TM3 compared with PP. In conclusion: (1) pregnancy-induced increases in exertional breathlessness reflected the normal awareness of increased V̇E and contractile respiratory muscle effort; (2) mechanical adaptations of the respiratory system, including recruitment of resting IC and increased bronchodilatation, accommodated the increased VT while preserving effort–displacement and breathlessness–V̇E relationships; and (3) dynamic mechanical ventilatory constraints contributed to respiratory discomfort near the limits of tolerance in late gestation. PMID:18687714

A practical guide to exercise training for heart failure patients.

PubMed

Smart, Neil; Fang, Zhi You; Marwick, Thomas H

2003-02-01

Exercise training has been shown to improve exercise capacity in patients with heart failure. We sought to examine the optimal strategy of exercise training for patients with heart failure. Review of the published data on the characteristics of the training program, with comparison of physiologic markers of exercise capacity in heart failure patients and healthy individuals and comparison of the change in these characteristics after an exercise training program. Many factors, including the duration, supervision, and venue of exercise training; the volume of working muscle; the delivery mode (eg, continuous vs. intermittent exercise), training intensity; and the concurrent effects of medical treatments may influence the results of exercise training in heart failure. Starting in an individually prescribed and safely monitored hospital-based program, followed by progression to an ongoing and progressive home program of exercise appears to be the best solution to the barriers of anxiety, adherence, and "ease of access" encountered by the heart failure patient. Various exercise training programs have been shown to improve exercise capacity and symptom status in heart failure, but these improvements may only be preserved with an ongoing maintenance program.

Estimation of cardiac reserve by peak power: validation and initial application of a simplified index

NASA Technical Reports Server (NTRS)

Armstrong, G. P.; Carlier, S. G.; Fukamachi, K.; Thomas, J. D.; Marwick, T. H.

1999-01-01

OBJECTIVES: To validate a simplified estimate of peak power (SPP) against true (invasively measured) peak instantaneous power (TPP), to assess the feasibility of measuring SPP during exercise and to correlate this with functional capacity. DESIGN: Development of a simplified method of measurement and observational study. SETTING: Tertiary referral centre for cardiothoracic disease. SUBJECTS: For validation of SPP with TPP, seven normal dogs and four dogs with dilated cardiomyopathy were studied. To assess feasibility and clinical significance in humans, 40 subjects were studied (26 patients; 14 normal controls). METHODS: In the animal validation study, TPP was derived from ascending aortic pressure and flow probe, and from Doppler measurements of flow. SPP, calculated using the different flow measures, was compared with peak instantaneous power under different loading conditions. For the assessment in humans, SPP was measured at rest and during maximum exercise. Peak aortic flow was measured with transthoracic continuous wave Doppler, and systolic and diastolic blood pressures were derived from brachial sphygmomanometry. The difference between exercise and rest simplified peak power (Delta SPP) was compared with maximum oxygen uptake (VO(2)max), measured from expired gas analysis. RESULTS: SPP estimates using peak flow measures correlated well with true peak instantaneous power (r = 0.89 to 0.97), despite marked changes in systemic pressure and flow induced by manipulation of loading conditions. In the human study, VO(2)max correlated with Delta SPP (r = 0.78) better than Delta ejection fraction (r = 0.18) and Delta rate-pressure product (r = 0.59). CONCLUSIONS: The simple product of mean arterial pressure and peak aortic flow (simplified peak power, SPP) correlates with peak instantaneous power over a range of loading conditions in dogs. In humans, it can be estimated during exercise echocardiography, and correlates with maximum oxygen uptake better than ejection fraction or rate-pressure product.

Nonparetic Knee Extensor Strength Is the Determinant of Exercise Capacity of Community-Dwelling Stroke Survivors

PubMed Central

Wang, Wei-Te; Huang, Ling-Tzu; Chou, Ya-Hui; Wei, Ta-Sen; Lin, Chung-Che

2014-01-01

Objective. To investigate the relationship among walking speed, exercise capacity, and leg strength in community dwelling stroke subjects and to evaluate which one was the leading determinant factor of them. Design. This is a descriptive, cross-sectional study. Thirty-five chronic stroke patients who were able to walk independently in their community were enrolled. Walking speed was evaluated by using the 12-meter walking test. A maximal exercise test was used to determine the stroke subjects' exercise capacity. Knee extensor strength, measured as isokinetic torque, was assessed by isokinetic dynamometer. Results. The main walking speed of our subjects was 0.52 m/s. Peak oxygen uptake (VO2 peak) was 1.21 ± 0.43 L/min. Knee extensor strength, no matter whether paretic or nonparetic side, was significantly correlated to 12-meter walking speed and exercise capacity. Linear regression also showed the strength of the affected knee extensor was the determinant of walking speed and that of the nonparetic knee extensor was the determinant of exercise capacity in community dwelling stroke subjects. Conclusions. Walking speed and peak oxygen uptake were markedly decreased after stroke. Knee extensor strength of nonparetic leg was the most important determinant of exercise capacity of the community-dwelling stroke subjects. Knee extensor strengthening should be emphasized to help stroke patient to achieve optimal community living. PMID:25197712

Nonparetic knee extensor strength is the determinant of exercise capacity of community-dwelling stroke survivors.

PubMed

Wang, Wei-Te; Huang, Ling-Tzu; Chou, Ya-Hui; Wei, Ta-Sen; Lin, Chung-Che

2014-01-01

To investigate the relationship among walking speed, exercise capacity, and leg strength in community dwelling stroke subjects and to evaluate which one was the leading determinant factor of them. This is a descriptive, cross-sectional study. Thirty-five chronic stroke patients who were able to walk independently in their community were enrolled. Walking speed was evaluated by using the 12-meter walking test. A maximal exercise test was used to determine the stroke subjects' exercise capacity. Knee extensor strength, measured as isokinetic torque, was assessed by isokinetic dynamometer. The main walking speed of our subjects was 0.52 m/s. Peak oxygen uptake (VO₂ peak) was 1.21 ± 0.43 L/min. Knee extensor strength, no matter whether paretic or nonparetic side, was significantly correlated to 12-meter walking speed and exercise capacity. Linear regression also showed the strength of the affected knee extensor was the determinant of walking speed and that of the nonparetic knee extensor was the determinant of exercise capacity in community dwelling stroke subjects. Walking speed and peak oxygen uptake were markedly decreased after stroke. Knee extensor strength of nonparetic leg was the most important determinant of exercise capacity of the community-dwelling stroke subjects. Knee extensor strengthening should be emphasized to help stroke patient to achieve optimal community living.

Discrepancy between functional exercise capacity and daily physical activity: a cross-sectional study in patients with mild to moderate COPD.

PubMed

Fastenau, Annemieke; van Schayck, Onno C P; Gosselink, Rik; Aretz, Karin C P M; Muris, Jean W M

2013-12-01

In patients with moderate to severe chronic obstructive pulmonary disease (COPD) the six-minute walk distance reflects the functional exercise level for daily physical activity. It is unknown if this also applies to patients with mild to moderate COPD in primary care. To assess the relationship between functional exercise capacity and physical activity in patients with mild to moderate COPD. A cross-sectional study was performed in 51 patients with mild to moderate COPD in primary care. Functional exercise capacity was assessed by the six-minute walk test and physical activity was measured with an accelerometer-based activity monitor. Functional exercise capacity was close to normal values. However, the daily physical activity of the patients could be classified as 'sedentary' and 'low active'. No significant correlations were observed between six-minute walk distance (% predicted) and any of the physical activity variables (steps per day, movement intensity during walking, total active time, total walking time, physical activity level, and time spent in moderate physical activity). A discrepancy was found between functional exercise capacity and daily physical activity in patients with mild to moderate COPD recruited and assessed in primary care. We conclude that these variables represent two different concepts. Our results reinforce the importance of measuring daily physical activity in order to fine-tune treatment (i.e. focusing on enhancement of exercise capacity or behavioural change, or both).

Distractive Auditory Stimuli in the Form of Music in Individuals With COPD: A Systematic Review.

PubMed

Lee, Annemarie L; Desveaux, Laura; Goldstein, Roger S; Brooks, Dina

2015-08-01

Music has been used as a distractive auditory stimulus (DAS) in patients with COPD, but its effects are unclear. This systematic review aimed to establish the effect of DAS on exercise capacity, symptoms, and health-related quality of life (HRQOL) under three conditions: (1) during exercise training, (2) during exercise testing, and (3) for symptom management at rest. Randomized controlled or crossover trials as well as cohort studies of DAS during exercise training, during formal exercise testing, and for symptom management among individuals with COPD were identified from a search of seven databases. Two reviewers independently assessed study quality. Weighted mean differences (WMDs) with 95% CIs were calculated using a random-effects model. Thirteen studies (12 of which were randomized controlled or crossover trials) in 415 participants were included. DAS increased exercise capacity when applied over at least 2 months of exercise training (WMD, 98 m; 95% CI, 47-150 m). HRQOL improved only after a training duration of 3 months. Less dyspnea was noted with DAS during exercise training, but this was not consistently observed in short-term exercise testing or as a symptom management strategy at rest. DAS appears to reduce symptoms of dyspnea and fatigue when used during exercise training, with benefits observed in exercise capacity and HRQOL. When applied during exercise testing, the effects on exercise capacity and symptoms and as a strategy for symptom management at rest are inconsistent.

Effects of resistance training, detraining, and retraining on strength and functional capacity in elderly.

PubMed

Sakugawa, Raphael Luiz; Moura, Bruno Monteiro; Orssatto, Lucas Bet da Rosa; Bezerra, Ewertton de Souza; Cadore, Eduardo Lusa; Diefenthaeler, Fernando

2018-05-17

The interruption of training (detraining) results in loss of the gains acquired. Partial retention could occur after detraining, and variation in training stimuli may optimize retraining adaptations. To evaluate the effect of a resistance-retraining program on strength and functional capacity performance after a detraining period. Ten elderly men and women (63-68 years) completed 12 weeks of training, 16 weeks of detraining, and 8 weeks of retraining. One-repetition maximum (1-RM) at 45° leg press, maximum isometric knee extension torque, rate of torque development (RTD), 30-s sit-to-stand, timed up and go, and stair ascent and descent tests were assessed. The 1-RM increased after training (p < 0.01) and remained higher after a detraining period when compared to pre-training (p < 0.01). Post-retraining values were not different from post-training period (p > 0.05). For RTD and 30-s sit-to-stand, there was an increase after retraining when compared to pre-training values (p < 0.05). For timed up and go and stair ascent and descent, reductions were observed between pre-training and post-training periods (p < 0.05), only timed up and go increased after the detraining period (p < 0.01). After 16 weeks of detraining, the maximum strength did not return to baseline levels, and a retraining with explosive strength exercise sessions can recover maximum strength gains, RTD, and functional capacity at the same level obtained after a detraining period. The inclusion of an explosive strength session in retraining period improves RTD and 30-s sit-to-stand performance and can accelerate the recovery of strength after a detraining period.

Selective effects of different fatigue protocols on the function of upper body muscles assessed through the force-velocity relationship.

PubMed

García-Ramos, Amador; Torrejón, Alejandro; Feriche, Belén; Morales-Artacho, Antonio J; Pérez-Castilla, Alejandro; Padial, Paulino; Jaric, Slobodan

2018-02-01

This study explored the feasibility of the force-velocity relationship (F-V) to detect the acute effects of different fatigue protocols on the selective changes of the maximal capacities of upper body muscles to produce force, velocity, and power. After determining the bench press one-repetition maximum (1RM), participants' F-V relationships were assessed during the bench press throw exercise on five separate sessions after performing one of the following fatiguing protocols: 60%1RM failure, 60%1RM non-failure, 80%1RM failure, 80%1RM non-failure, and no-fatigue. In the non-failure protocols, participants performed half the maximum number of repetitions than in their respective failure protocols. The main findings revealed that (1) all F-V relationships were highly linear (median r = 0.997 and r = 0.982 for averaged across participants and individual data, respectively), (2) the fatiguing protocols were ranked based on the magnitude of power loss as follows: 60%1RM failure > 80%1RM failure > 60%1RM non-failure > 80%1RM non-failure, while (3) the assessed maximum force and velocity outputs showed a particularly prominent reduction in the protocols based on the lowest and highest levels of fatigue (i.e., 80%1RM non-failure and 60%1RM failure), respectively. The results support the use of F-V to assess the effects of fatigue on the distinctive capacities of the muscles to produce force, velocity, and power output while performing multi-joint tasks, while the assessed maximum force and velocity capacities showed a particularly prominent reduction in the protocols based on the lowest and highest levels of fatigue (i.e., 80%1RM non-failure and 60%1RM failure), respectively.

Hypercholesterolemia Impairs Exercise Capacity in Mice

PubMed Central

Maxwell, Andrew J.; Niebauer, Josef; Lin, Patrick S.; Tsao, Philip S.; Bernstein, Daniel; Cooke, John P.

2011-01-01

Objective We previously reported an attenuation of both exercise hyperemia and measures of aerobic capacity in hypercholesterolemic mice. In this study we expanded upon the previous findings by examining the temporal and quantitative relationship of hypercholesterolemia to aerobic and anaerobic capacity and by exploring several potential mechanisms of dysfunction. Methods Eight-week old wild type (n=123) and apoE knockout (n=79) C57BL/6J mice were divided into groups with distinct cholesterol levels by feeding regular or high fat diets. At various ages the mice underwent treadmill ergospirometry. To explore mechanisms, aortic ring vasodilator function and nitrate (NOx) activity, urinary excretion of NOx, running muscle microvascular density and citrate synthase activity, as well as myocardial mass and histologic evidence of ischemia were measured. Results At 8 weeks of age, all mice had similar measures of exercise capacity. All indices of aerobic exercise capacity progressively declined at 12 and 20 weeks of age in the hypercholesterolemic mice as cholesterol levels increased while indices of anaerobic capacity remained unaffected. Across the 4 cholesterol groups, the degree of aerobic dysfunction was related to serum cholesterol levels; a relationship that was maintained after correcting for confounding factors. Associated with the deterioration in exercise capacity was a decline in measures of nitric oxide-mediated vascular function while there was no evidence of aberrations in functional or oxidative capacities or in other components of transport capacity. Conclusion Aerobic exercise dysfunction is observed in murine models of genetic and diet-induced hypercholesterolemia and is associated with a reduction in vascular nitric oxide production. PMID:19651675

Maximum static inspiratory and expiratory pressures with different lung volumes

PubMed Central

Lausted, Christopher G; Johnson, Arthur T; Scott, William H; Johnson, Monique M; Coyne, Karen M; Coursey, Derya C

2006-01-01

Background Maximum pressures developed by the respiratory muscles can indicate the health of the respiratory system, help to determine maximum respiratory flow rates, and contribute to respiratory power development. Past measurements of maximum pressures have been found to be inadequate for inclusion in some exercise models involving respiration. Methods Maximum inspiratory and expiratory airway pressures were measured over a range of lung volumes in 29 female and 19 male adults. A commercial bell spirometry system was programmed to occlude airflow at nine target lung volumes ranging from 10% to 90% of vital capacity. Results In women, maximum expiratory pressure increased with volume from 39 to 61 cmH2O and maximum inspiratory pressure decreased with volume from 66 to 28 cmH2O. In men, maximum expiratory pressure increased with volume from 63 to 97 cmH2O and maximum inspiratory pressure decreased with volume from 97 to 39 cmH2O. Equations describing pressures for both sexes are: Pe/Pmax = 0.1426 Ln( %VC) + 0.3402 R2 = 0.95 Pi/Pmax = 0.234 Ln(100 - %VC) - 0.0828 R2 = 0.96 Conclusion These results were found to be consistent with values and trends obtained by other authors. Regression equations may be suitable for respiratory mechanics models. PMID:16677384

Brain, Behavior, and Immunity: Effects and potential mechanisms of exercise training on cancer progression: A translational perspective

Cancer.gov

Review of the extant epidemiological evidence examining the association between exercise behavior, function capacity/exercise capacity, and cancer-specific recurrence and mortality as well as all-cause mortality individuals following a cancer diagnosis.

Rapamycin increases grip strength and attenuates age-related decline in maximal running distance in old low capacity runner rats.

PubMed

Xue, Qian-Li; Yang, Huanle; Li, Hui-Fen; Abadir, Peter M; Burks, Tyesha N; Koch, Lauren G; Britton, Steven L; Carlson, Joshua; Chen, Laura; Walston, Jeremy D; Leng, Sean X

2016-04-01

Rapamycin is known to extend lifespan. We conducted a randomized placebo-controlled study of enteric rapamycin-treatment to evaluate its effect on physical function in old low capacity runner (LCR) rats, a rat model selected from diverse genetic background for low intrinsic aerobic exercise capacity without genomic manipulation and characterized by increased complex disease risks and aging phenotypes. The study was performed in 12 male and 16 female LCR rats aged 16-22 months at baseline. The treatment group was fed with rapamycin-containing diet pellets at approximately 2.24mg/kg body weight per day and the placebo group with the same diet without rapamycin for six months. Observation was extended for additional 2 months. Physical function measurements include grip strength measured as maximum tensile force using a rat grip strength meter and maximum running distance (MRD) using rat physical treadmill test. The results showed that rapamycin improved grip strength by 13% (p=.036) and 60% (p=.001) from its baseline in female and male rats, respectively. Rapamycin attenuated MRD decline by 66% (p=.001) and 46% (p=.319) in females and males, respectively. These findings provide initial evidence for beneficial effect of rapamycin on physical functioning in an aging rat model of high disease risks with significant implication in humans.

Clinical Determinants of Incremental Shuttle Walk Test in Adults with Bronchiectasis.

PubMed

Yildiz, Sulenur; Inal-Ince, Deniz; Calik-Kutukcu, Ebru; Vardar-Yagli, Naciye; Saglam, Melda; Arikan, Hulya; Coplu, Lutfi

2018-06-01

Exercise capacity is impaired in patients with bronchiectasis. Incremental shuttle walk test (ISWT) stresses cardiorespiratory system physiologically to symptom-limited maximal exercise capacity. The purpose of this study was to investigate the clinical determinants of ISWT in adults with non-cystic fibrosis (CF) bronchiectasis. Forty-one clinically stable bronchiectasis patients aged 18-72 years (27 females, 14 males) participated in the study. Subjects' demographics and physical characteristics were recorded. Bronchiectasis Severity Index was used to identify disease severity. Pulmonary function test was performed. Dyspnea perception was assessed using the modified Medical Research Council Dyspnea Scale. Maximum inspiratory and expiratory pressures were measured. Peripheral muscle strength using a hand held dynamometer was measured. ISWT was performed to determine exercise capacity. Fatigue Severity Scale, Hospital Anxiety and Depression Scale, Leicester Cough Questionnaire were used to determine fatigue, psychosocial status, and quality of life. Patients' mean ISWT distance was 469.5 m. The ISWT distance was significantly related with age (r = - 0.472), height (r = 0.469), gender (r = 0.520), FEV 1 (r = 0.651), and FVC (r = 0.545, p < 0.05). Quadriceps muscle strength was higher in males (p = 0.001) as compared to females. Age and gender were identified as independent predictors of the ISWT, explaining 42% of variance in ISWT distance (r = 0.649, r 2  = 0.421, F (2,38)  = 13.794, p < 0.001). The clinical determinants of ISWT in clinically stable patients with non-CF bronchiectasis are age and gender. Pulmonary function, dyspnea perception, muscle strength, disease severity, fatigue, psychosocial factors, and health-related quality of life seems to have an independent effect on ISWT in this group of patients with bronchiectasis.

The effects of dance music jump rope exercise on pulmonary function and body mass index after music jump rope exercise in overweight adults in 20's.

PubMed

Seo, KyoChul

2017-08-01

[Purpose] The purpose of this study was to examine the effect of a dance music jump rope exercise on changes Pulmonary Function and body mass index in female overweight subjects in their 20's. [Subjects and Methods] The subjects were randomly assigned to the dance music jump rope exercise group and the stationary cycle exercise group. All subjects have conducted the exercises three times a week for four weeks. Pulmonary function was evaluated using a spirometer, and body mass index was evaluated using an InBody 3.0. [Results] The findings of this study showed significant improvements in the voluntary capacity and body mass index of the experimental groups. Vital capacity was higher in the music jump rope exercise group than the stationary cycle exercise group, and body mass index was lower in the music jump rope exercise group than the stationary cycle exercise group. [Conclusion] This study showed that the dance music jump rope exercise can be used to improve vital capacity and body mass index.

Supervised Phase II Cardiac Exercise Therapy Shortens the Recovery of Exercise Capacity in Patients with Acute Myocardial Infarction

PubMed Central

Lee, Chih-Wei; Wang, Ji-Hung; Hsieh, Jen-Che; Hsieh, Tsung-Cheng; Wu, Yu-Zu; Chen, Tung-Wei; Huang, Chien-Hui

2014-01-01

[Purpose] To investigate the effects of Phase II cardiac exercise therapy (CET) on exercise capacity and changes in coronary risk factors (CRFs) of patients with acute myocardial infarction (AMI). [Subjects] Thirty male subjects with AMI were divided into an experimental group (EG) and a control group (CG). Another 30 age-matched subjects with patent coronary arteries served as a normal-control group (NCG). [Methods] Subjects in EG (n=20) trained using a stationary bicycle for 30 min at their target heart rate twice a week for 8 weeks. Exercise capacity was defined as the maximal metabolic equivalents (METs) that subjects reached during the symptom-limited maximal exercise test. HR, BP and RPP were recorded. Subjects in EG and CG received exercise tests and screening for CRFs at the beginning of, end of, and 3 months after Phase II CET, while subjects in NCG participated only in the 1st test. [Results] METs of CG did not improve until the 3rd test, while RPP at the 2nd test showed a significant increase. However, EG showed increased METs at the 2nd test without increase of RPP, and increased their high density lipoprotein cholesterol (HDL-C) during the follow-up period between the 2nd and 3rd tests. [Conclusion] Phase II CET shortens the recovery time of exercise capacity, helps to maintain the gained exercise capacity and increases HDL-C in phase III. PMID:25276046

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.

Exercise training improves in vivo endothelial repair capacity of early endothelial progenitor cells in subjects with metabolic syndrome.

PubMed

Sonnenschein, Kristina; Horváth, Tibor; Mueller, Maja; Markowski, Andrea; Siegmund, Tina; Jacob, Christian; Drexler, Helmut; Landmesser, Ulf

2011-06-01

Endothelial dysfunction and injury are considered to contribute considerably to the development and progression of atherosclerosis. It has been suggested that intense exercise training can increase the number and angiogenic properties of early endothelial progenitor cells (EPCs). However, whether exercise training stimulates the capacity of early EPCs to promote repair of endothelial damage and potential underlying mechanisms remain to be determined. The present study was designed to evaluate the effects of moderate exercise training on in vivo endothelial repair capacity of early EPCs, and their nitric oxide and superoxide production as characterized by electron spin resonance spectroscopy analysis in subjects with metabolic syndrome. Twenty-four subjects with metabolic syndrome were randomized to an 8 weeks exercise training or a control group. Superoxide production and nitric oxide (NO) availability of early EPCs were characterized by using electron spin resonance (ESR) spectroscopy analysis. In vivo endothelial repair capacity of EPCs was examined by transplantation into nude mice with defined carotid endothelial injury. Endothelium-dependent, flow-mediated vasodilation was analysed using high-resolution ultrasound. Importantly, exercise training resulted in a substantially improved in vivo endothelial repair capacity of early EPCs (24.0 vs 12.7%; p < 0.05) and improved endothelium-dependent vasodilation. Nitric oxide production of EPCs was substantially increased after exercise training, but not in the control group. Moreover, exercise training reduced superoxide production of EPCs, which was not observed in the control group. The present study suggests for the first time that moderate exercise training increases nitric oxide production of early endothelial progenitor cells and reduces their superoxide production. Importantly, this is associated with a marked beneficial effect on the in vivo endothelial repair capacity of early EPCs in subjects with metabolic syndrome.

Lung volumes identify an at-risk group in persons with prolonged secondhand tobacco smoke exposure but without overt airflow obstruction.

PubMed

Arjomandi, Mehrdad; Zeng, Siyang; Geerts, Jeroen; Stiner, Rachel K; Bos, Bruce; van Koeverden, Ian; Keene, Jason; Elicker, Brett; Blanc, Paul D; Gold, Warren M

2018-01-01

Exposure to secondhand smoke (SHS) is associated with occult obstructive lung disease as evident by abnormal airflow indices representing small airway disease despite having preserved spirometry (normal forced expiratory volume in 1 s-to-forced vital capacity ratio, FEV 1 /FVC). The significance of lung volumes that reflect air trapping in the presence of preserved spirometry is unclear. To investigate whether lung volumes representing air trapping could determine susceptibility to respiratory morbidity in people with SHS exposure but without spirometric chronic obstructive pulmonary disease, we examined a cohort of 256 subjects with prolonged occupational SHS exposure and preserved spirometry. We elicited symptom prevalence by structured questionnaires, examined functional capacity (maximum oxygen uptake, VO 2max ) by exercise testing, and estimated associations of those outcomes with air trapping (plethysmography-measured residual volume-to-total lung capacity ratio, RV/TLC), and progressive air trapping with exertion (increase in fraction of tidal breathing that is flow limited on expiration during exercise (per cent of expiratory flow limitation, %EFL)). RV/TLC was within the predicted normal limits, but was highly variable spanning 22%±13% and 16%±8% across the increments of FEV 1 /FVC and FEV 1 , respectively. Respiratory complaints were prevalent (50.4%) with the most common symptom being ≥2 episodes of cough per year (44.5%). Higher RV/TLC was associated with higher OR of reporting respiratory symptoms (n=256; r 2 =0.03; p=0.011) and lower VO 2max (n=179; r 2 =0.47; p=0.013), and %EFL was negatively associated with VO 2max (n=32; r 2 =0.40; p=0.017). In those at risk for obstruction due to SHS exposure but with preserved spirometry, higher RV/TLC identifies a subgroup with increased respiratory symptoms and lower exercise capacity.

Effect of low glycemic index food and postprandial exercise on blood glucose level, oxidative stress and antioxidant capacity.

PubMed

Kasuya, Noriaki; Ohta, Shoichiro; Takanami, Yoshikazu; Kawai, Yukari; Inoue, Yutaka; Murata, Isamu; Kanamoto, Ikuo

2015-04-01

Low glycemic index (GI) food and postprandial exercise are non-drug therapies for improving postprandial hyperglycemia. The present randomized, crossover study investigated the effect of low GI food combined with postprandial exercise on postprandial blood glucose level, oxidative stress and antioxidant capacity. A total of 13 healthy subjects were each used in four experiments: i) rice only (control), ii) salad prior to rice (LGI), iii) exercise following rice (EX) and iv) salad prior to rice and exercise following rice (MIX). The blood glucose level, oxidative stress and antioxidant capacity were then measured. At 60 min after the meal, the blood glucose level was observed to be increased in the MIX group compared with that in the LGI group. Furthermore, at 180 min, the antioxidant capacity was found to be reduced in the MIX group compared with those of the LGI and EX groups. These findings suggest that low GI food combined with postprandial exercise does not improve postprandial hyperglycemia. It may be necessary to establish optimal timing and intensity when combining low GI food with postprandial exercise to improve postprandial hyperglycemia.

Effects of new sports tennis type exercise on aerobic capacity, follicle stimulating hormone and N-terminal telopeptide in the postmenopausal women.

PubMed

Shin, Hyun-Jae; Lee, Ha-Yan; Cho, Hye-Young; Park, Yun-Jin; Moon, Hyung-Hoon; Lee, Sung-Hwan; Lee, Sung-Ki; Kim, Myung-Ki

2014-04-01

Menopause is characterized by rapid decreases in bone mineral density, aerobic fitness, muscle strength, and balance. In the present study, we investigated the effects of new sports tennis type exercise on aerobic capacity, follicle stimulating hormone (FSH) and N-terminal telopeptide (NTX) in the postmenopausal women. Subjects were consisted of 20 postmenopausal women, who had not menstruated for at least 1 yr and had follicle-stimulating hormone levels > 35 mIU/L, estradiol levels< 40 pg/mL. The subjects were randomly divided into two groups: control group (n= 10), new sports tennis type exercise group (n= 10). New sports tennis type exercise was consisted of warm up (10 min), new sports tennis type exercise (40 min), cool down (10 min) 3 days a per week for 12 weeks. The aerobic capacities were increased by 12 weeks new sports tennis type exercise. New sports tennis type exercise significantly increased FSH and NTx levels, indicating biochemical markers of bone formation and resorption. These findings indicate that 12 weeks of new sports tennis type exercise can be effective in prevention of bone loss and enhancement of aerobic capacity in postmenopausal women.

Exercise training enhances aerobic capacity in juvenile estuarine crocodiles (Crocodylus porosus).

PubMed

Owerkowicz, Tomasz; Baudinette, Russell V

2008-06-01

Aerobic capacity (VO2max) of endothermic vertebrates is known to increase with exercise training, but this effect has not been found to-date in non-avian reptiles. We exercised juvenile estuarine crocodiles (Crocodylus porosus) to walk at 0.75-0.88 km/h on a treadmill for up to 20 min a day over 16 weeks, and compared their aerobic performance with that of unexercised crocodiles. In the exercised group, VO2max increased from 6.9 to 8.5 mLO2/kg/min (+28%), and locomotor endurance increased from 3.8 to 6.9 min (+82%). Neither VO2max nor endurance changed significantly in the sedentary group. This finding extends the exercise training effect onto another vertebrate clade, and demonstrates that ectothermic amniotes are capable of elevating their aerobic capacity in response to exercise training. We propose that differences in cardiopulmonary structure and function in non-avian reptiles may be responsible for the absence (in squamates) or presence (in crocodilians) of a strong training effect on aerobic capacity.

Ginseng improves pulmonary functions and exercise capacity in patients with COPD.

PubMed

Gross, D; Shenkman, Z; Bleiberg, B; Dayan, M; Gittelson, M; Efrat, R

2002-01-01

Ginseng is a root that has been used to treat patients with various illnesses for the last 2000 years. The purpose of this study was to evaluate the effects of Ginseng extract (G115) on Pulmonary Function Tests (PFTs), Maximum Voluntary Ventilation (MVV), Maximum Inspiratory Pressure (MIP) and Maximal Oxygen Consumption (VO2max) in patients with moderately-severe Chronic Obstructive Pulmonary Disease (COPD). Ninety-two adults were randomly divided into the experimental (n = 49, G115 100 mg bid for three months) and placebo-control (n = 43) groups. PFTs, MVV and MIP were studied before treatment and every two weeks for the 3-month-study period. Exercise test and VO2max measurements were performed before the beginning and after six weeks and three months. P lower than 0.05 was considered significant. Baseline demographics and pulmonary parameters were similar between the groups. In the experimental, but not in the control group, all parameters significantly increased above baseline and compared with the placebo group. Maximum increase, compared with baseline was FVC-32.5%, FEV1.0-27.0%, PEF-27.5%, FEF50-45.4%, FEF75-56.9%, MVV-40.4%, MIP-47.0% and VO2max-37.5%. No side effects were observed. G115 100 mg bid for three months, but not placebo, improved PFTs, MVV, MIP and VO2 max in patients with moderately-severe COPD with no side effects.

Beneficial effects of dark chocolate on exercise capacity in sedentary subjects: underlying mechanisms. A double blind, randomized, placebo controlled trial.

PubMed

Taub, Pam R; Ramirez-Sanchez, Israel; Patel, Minal; Higginbotham, Erin; Moreno-Ulloa, Aldo; Román-Pintos, Luis Miguel; Phillips, Paul; Perkins, Guy; Ceballos, Guillermo; Villarreal, Francisco

2016-09-14

In heart failure patients the consumption of (-)-epicatechin ((-)-Epi)-rich cocoa can restore skeletal muscle (SkM) mitochondrial structure and decrease biomarkers of oxidative stress. However, nothing is known about its effects on exercise capacity and underlying mechanisms in normal, sedentary subjects. Twenty normal, sedentary subjects (∼50 years old) were randomized to placebo or dark chocolate (DC) groups and consumed 20 g of the products for 3 months. Subjects underwent before and after treatment, bicycle ergometry to assess VO2 max and work, SkM biopsy to assess changes in mitochondrial density, function and oxidative stress and blood sampling to assess metabolic endpoints. Seventeen subjects completed the trial. In the DC group (n = 9), VO2 max increased (17% increase, p = 0.056) as well as maximum work (watts) achieved (p = 0.026) with no changes with placebo (n = 8). The DC group evidenced increases in HDL levels (p = 0.005) and decreased triglycerides (p = 0.07). With DC, SkM evidenced significant increases in protein levels for LKB1, AMPK and PGC1α and in their active forms (phosphorylated AMPK and LKB1) as well as in citrate synthase activity while no changes were observed in mitochondrial density. With DC, significant increases in SkM reduced glutathione levels and decreases in protein carbonylation were observed. Improvements in maximum work achieved and VO2 max may be due to DC activation of upstream control systems and enhancement of SkM mitochondria efficiency. Larger clinical studies are warranted to confirm these observations.

Beneficial effects of dark chocolate on exercise capacity in sedentary subjects: Underlying mechanisms

PubMed Central

Taub, Pam R.; Ramirez-Sanchez, Israel; Patel, Minal; Higginbotham, Erin; Moreno-Ulloa, Aldo; Román-Pintos, Luis Miguel; Phillips, Paul; Perkins, Guy; Ceballos, Guillermo; Villarreal, Francisco

2016-01-01

In heart failure patients the consumption of (-)-epicatechin ((-)-Epi)-rich cocoa can restore skeletal muscle (SkM) mitochondrial structure and decrease biomarkers of oxidative stress. However, nothing is known about its effects on exercise capacity and underlying mechanisms in normal, sedentary subjects. Twenty normal, sedentary subjects (∼50 years old) were randomized to placebo or dark chocolate (DC) groups and consumed 20 g of the products for 3 months. Subjects underwent before and after treatment, bicycle ergometry to assess VO2 max and work, SkM biopsy to assess changes in mitochondrial density, function and oxidative stress and blood sampling to assess metabolic endpoints. Seventeen subjects completed the trial. In the DC group (n=9), VO2 max increased (17% increase, p=0.056) as well as maximum work (watts) achieved (p=0.026) with no changes with placebo (n=8). The DC group evidenced increases in HDL levels (p=0.005) and decreased triglycerides (p=0.07). With DC, SkM evidenced significant increases in protein levels for LKB1, AMPK and PGC1α and in their active forms (phosphorylated AMPK and LKB1) as well as in citrate synthase activity while no changes were observed in mitochondrial density. With DC, significant increases in SkM reduced glutathione levels and decreases in protein carbonylation were observed. Improvements in maximum work achieved and VO2 max may be due to DC activation of upstream control systems and enhancement of SkM mitochondria efficiency. Larger clinical studies are warranted to confirm these observations. PMID:27491778

The physiology of mountain biking.

PubMed

Impellizzeri, Franco M; Marcora, Samuele M

2007-01-01

Mountain biking is a popular outdoor recreational activity and an Olympic sport. Cross-country circuit races have a winning time of approximately equal 120 minutes and are performed at an average heart rate close to 90% of the maximum, corresponding to 84% of maximum oxygen uptake (VO2max). More than 80% of race time is spent above the lactate threshold. This very high exercise intensity is related to the fast starting phase of the race; the several climbs, forcing off-road cyclists to expend most of their effort going against gravity; greater rolling resistance; and the isometric contractions of arm and leg muscles necessary for bike handling and stabilisation. Because of the high power output (up to 500W) required during steep climbing and at the start of the race, anaerobic energy metabolism is also likely to be a factor of off-road cycling and deserves further investigation. Mountain bikers' physiological characteristics indicate that aerobic power (VO2max >70 mL/kg/min) and the ability to sustain high work rates for prolonged periods of time are prerequisites for competing at a high level in off-road cycling events. The anthropometric characteristics of mountain bikers are similar to climbers and all-terrain road cyclists. Various parameters of aerobic fitness are correlated to cross-country performance, suggesting that these tests are valid for the physiological assessment of competitive mountain bikers, especially when normalised to body mass. Factors other than aerobic power and capacity might influence off-road cycling performance and require further investigation. These include off-road cycling economy, anaerobic power and capacity, technical ability and pre-exercise nutritional strategies.

Cardiovascular rehabilitation soon after stroke using feedback-controlled robotics-assisted treadmill exercise: study protocol of a randomised controlled pilot trial

PubMed Central

2013-01-01

Background After experiencing a stroke, most individuals also suffer from cardiac disease, are immobile and thus have low endurance for exercise. Aerobic capacity is seriously reduced in these individuals and does not reach reasonable levels after conventional rehabilitation programmes. Cardiovascular exercise is beneficial for improvement of aerobic capacity in mild to moderate stroke. However, less is known about its impact on aerobic capacity, motor recovery, and quality-of-life in severely impaired individuals. The aim of this pilot study is to explore the clinical efficacy and feasibility of cardiovascular exercise with regard to aerobic capacity, motor recovery, and quality-of-life using feedback-controlled robotics-assisted treadmill exercise in non-ambulatory individuals soon after experiencing a stroke. Methods/Design This will be a single-centred single blind, randomised control trial with a pre-post intervention design. Subjects will be recruited early after their first stroke (≤20 weeks) at a neurological rehabilitation clinic and will be randomly allocated to an inpatient cardiovascular exercise programme that uses feedback-controlled robotics-assisted treadmill exercise (experimental) or to conventional robotics-assisted treadmill exercise (control). Intervention duration depends on the duration of each subject’s inpatient rehabilitation period. Aerobic capacity, as the primary outcome measure, will be assessed using feedback-controlled robotics-assisted treadmill-based cardiopulmonary exercise testing. Secondary outcome measures will include gait speed, walking endurance, standing function, and quality-of-life. Outcome assessment will be conducted at baseline, after each 4-week intervention period, and before clinical discharge. Ethical approval has been obtained. Discussion Whether cardiovascular exercise in non-ambulatory individuals early after stroke has an impact on aerobic capacity, motor recovery, and quality-of-life is not yet known. Feedback-controlled robotics-assisted treadmill exercise is a relatively recent intervention method and might be used to train and evaluate aerobic capacity in this population. The present pilot trial is expected to provide new insights into the implementation of early cardiovascular exercise for individuals with severe motor impairment. The findings of this study may guide future research to explore the effects of early cardiovascular activation after severe neurological events. Trial registration This trial is registered with the Clinical Trials.gov Registry (NCT01679600). PMID:24053609

Oxygen radical absorbance capacity (ORAC) and exercise-induced oxidative stress in trotters.

PubMed

Kinnunen, Susanna; Hyyppä, Seppo; Lehmuskero, Arja; Oksala, Niku; Mäenpää, Pekka; Hänninen, Osmo; Atalay, Mustafa

2005-12-01

Strenuous exercise is a potent inducer of oxidative stress, which has been suggested to be associated with disturbances in muscle homeostasis, fatigue and injury. There is no comprehensive or uniform view of the antioxidant status in horses. We have previously shown that moderate exercise induces protein oxidation in trotters. The aim of this study was to measure the antioxidative capacity of the horse in relation to different antioxidant components and oxidative stress markers after a single bout of moderate exercise to elucidate the mechanisms of antioxidant protection in horses. Eight clinically normal and regularly trained standard-bred trotters were treadmill-exercised for 53 min at moderate intensity. Blood samples were collected prior to and immediately after exercise and at 4 and 24 h of recovery. Muscle biopsies from the middle gluteal muscle were taken before exercise and after 4 h of recovery. Acute induction of oxygen radical absorbance capacity (ORAC) did not prevent exercise-induced oxidative stress, which was demonstrated by increased lipid hydroperoxides (LPO). Pre-exercise ORAC levels were, however, a determinant of total glutathione content of the blood after 4 and 24 h of recovery. Furthermore, baseline ORAC level correlated negatively with 4-h recovery LPO levels. Our results imply that horses are susceptible to oxidative stress, but a stronger antioxidant capacity may improve coping with exercise-induced oxidative stress.

Peripheral arterial disease decreases muscle torque and functional walking capacity in elderly.

PubMed

Dziubek, Wioletta; Bulińska, Katarzyna; Stefańska, Małgorzata; Woźniewski, Marek; Kropielnicka, Katarzyna; Jasiński, Tomasz; Jasiński, Ryszard; Pilch, Urszula; Dąbrowska, Grażyna; Skórkowska-Telichowska, Katarzyna; Wojcieszczyk-Latos, Joanna; Kałka, Dariusz; Janus, Agnieszka; Zywar, Katarzyna; Paszkowski, Rafał; Szuba, Andrzej

2015-08-01

The aim of this study is to compare values of force-velocity and functional walking capacity in elderly patients with intermittent claudication with respect to the control group. The study involved 135 individuals: 85-peripheral arterial disease (PAD) group diagnosed with stage II chronic lower limb ischemia, according to Fontaine's classification, and 50-control group. The studies included an assessment of walking capacity using a six-minute walk test (6MWT) and measurement of force-velocity parameters (peak torque-PTQ, total work-TW, average power-AVGP) of the lower limbs obtained by means of a functional dynamometry under isokinetic conditions. The peripheral arterial disease group is characterized by significantly lower values of force-velocity parameters compared to the control group (p<0.005). Walking capacity in this group is significantly reduced due to significant differences in the distance covered (p<0.0001), walking speed (p<0.01), and its intensity (p<0.01). Further, a positive correlation was found between the maximum distance specified in the six-minute walk test and lower limb muscle strength in the isokinetic test. Mean values of all force-velocity parameters and walk distance were significantly higher in the control group than in the peripheral arterial disease group. In the PAD group, in both men and women, the value of the agonist/antagonist ratio of both lower limbs are lower in men and women comparing to the control group. A rehabilitation program for patients with intermittent claudication must consider exercises improving strength, exercise capacity, and endurance in patients with PAD. Copyright © 2015 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

Daily Supine LBNP Treadmill Exercise Maintains Upright Exercise Capacity During 14 Days of Bed Rest

NASA Technical Reports Server (NTRS)

Ertl, Andy C.; Watenpaugh, D. E.; Hargens, Alan R.; Fortney, S. M.; Lee, S. M. C.; Ballard, R. E.; William, J. M.

1996-01-01

Exposure to microgravity or bed rest reduces upright exercise capacity. Exercise modes, durations, and intensities which will effectively and efficiently counteract such deconditioning are presently unresolved. We that daily supine treadmill interval training with lower body negative pressure (LBNP) would prevent reduction in upright exercise capacity during 14 days of 6 deg. head-down bed rest (BR). Eight healthy male subjects underwent two 14 day BR protocols separated by 3 months. In a crossover design, subjects either remained at strict BR or performed 40 min of daily exercise consisting of supine walking and running at intensities varying from 40-80% of pre-BR upright peak oxygen uptake (VO2). LBNP during supine exercise was used to provide 1.0 to 1.2 times body weight of footward force. An incremental upright treadmill test to measure submaximal and peak exercise responses was given pre- and post-BR. In the non-exercise condition, peak VO2 and time to exhaustion were reduced 16 +/- 4% and 10 +/- 1% (p less than 0.05), respectively, from pre-BR. With LBNP exercise these variables were not significantly different (NS) from pre-BR. During submaximal treadmill speeds after BR, heart rate was higher (11 +/- 11 bpm, p less than 0.05) and respiratory exchange ratio was elevated (p less than 0.05) in the no exercise condition. Both were maintained at pre-BR levels in the LBNP exercise condition (NS from pre-BR). Since this supine treadmill interval training with addition of LBNP maintained upright exercise responses and capacity during BR, this countermeasure may also be effective during space flight.

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.

Exercise Capacity and Response to Training Quantitative Trait Loci in a NZW X 129S1 Intercross and Combined Cross Analysis of Inbred Mouse Strains

PubMed Central

Massett, Michael P.; Avila, Joshua J.; Kim, Seung Kyum

2015-01-01

Genetic factors determining exercise capacity and the magnitude of the response to exercise training are poorly understood. The aim of this study was to identify quantitative trait loci (QTL) associated with exercise training in mice. Based on marked differences in training responses in inbred NZW (-0.65 ± 1.73 min) and 129S1 (6.18 ± 3.81 min) mice, a reciprocal intercross breeding scheme was used to generate 285 F2 mice. All F2 mice completed an exercise performance test before and after a 4-week treadmill running program, resulting in an increase in exercise capacity of 1.54 ± 3.69 min (range = -10 to +12 min). Genome-wide linkage scans were performed for pre-training, post-training, and change in run time. For pre-training exercise time, suggestive QTL were identified on Chromosomes 5 (57.4 cM, 2.5 LOD) and 6 (47.8 cM, 2.9 LOD). A significant QTL for post-training exercise capacity was identified on Chromosome 5 (43.4 cM, 4.1 LOD) and a suggestive QTL on Chromosomes 1 (55.7 cM, 2.3 LOD) and 8 (66.1 cM, 2.2 LOD). A suggestive QTL for the change in run time was identified on Chromosome 6 (37.8 cM, 2.7 LOD). To identify shared QTL, this data set was combined with data from a previous F2 cross between B6 and FVB strains. In the combined cross analysis, significant novel QTL for pre-training exercise time and change in exercise time were identified on Chromosome 12 (54.0 cM, 3.6 LOD) and Chromosome 6 (28.0 cM, 3.7 LOD), respectively. Collectively, these data suggest that combined cross analysis can be used to identify novel QTL and narrow the confidence interval of QTL for exercise capacity and responses to training. Furthermore, these data support the use of larger and more diverse mapping populations to identify the genetic basis for exercise capacity and responses to training. PMID:26710100

Exercise Capacity and Selected Physiological Factors by Ancestry and Residential Altitude: Cross-Sectional Studies of 9–10-Year-Old Children in Tibet

PubMed Central

Berntsen, Sveinung; Andersen, Lars Bo; Stigum, Hein; Ouzhuluobu; Nafstad, Per; Wu, Tianyi; Bjertness, Espen

2014-01-01

Abstract Bianba, Sveinung Bernsten, Lars Bo Andersen, Hein Stegum, Ouzhuluobu, Per Nafstad, Tianyi Wu, and Espen Bjertness. Exercise capacity and selected physiological factors by ancestry and residential altitude—Cross-sectional studies of 9–10-year-old children in Tibet. High Alt Med Biol. 15:162–169, 2014.—Aim: Several physiological compensatory mechanisms have enabled Tibetans to live and work at high altitude, including increased ventilation and pulmonary diffusion capacity, both of which serve to increase oxygen transport in the blood. The aim of the present study was to compare exercise capacity (maximal power output) and selected physiological factors (arterial oxygen saturation and heart rate at rest and during maximal exercise, resting hemoglobin concentration, and forced vital capacity) in groups of native Tibetan children living at different residential altitudes (3700 vs. 4300 m above sea level) and across ancestry (native Tibetan vs. Han Chinese children living at the same altitude of 3700 m). Methods: A total of 430 9–10-year-old native Tibetan children from Tingri (4300 m) and 406 native Tibetan- and 406 Han Chinese immigrants (77% lowland-born and 33% highland-born) from Lhasa (3700 m) participated in two cross-sectional studies. The maximal power output (Wmax) was assessed using an ergometer cycle. Results: Lhasa Tibetan children had a 20% higher maximal power output (watts/kg) than Tingri Tibetan and 4% higher than Lhasa Han Chinese. Maximal heart rate, arterial oxygen saturation at rest, lung volume, and arterial oxygen saturation were significantly associated with exercise capacity at a given altitude, but could not fully account for the differences in exercise capacity observed between ancestry groups or altitudes. Conclusions: The superior exercise capacity in native Tibetans vs. Han Chinese may reflect a better adaptation to life at high altitude. Tibetans at the lower residential altitude of 3700 m demonstrated a better exercise capacity than residents at a higher altitude of 4300 m when measured at their respective residential altitudes. Such altitude- or ancestry-related difference could not be fully attributed to the physiological factors measured. PMID:24836751

Effect of changes in fat availability on exercise capacity in McArdle disease.

PubMed

Andersen, Susanne T; Jeppesen, Tina D; Taivassalo, Tanja; Sveen, Marie-Louise; Heinicke, Katja; Haller, Ronald G; Vissing, John

2009-06-01

The major fuel for exercising muscle at low exercise intensities is fat. To investigate the role of fat metabolism in McArdle disease (also known as glycogen storage disease type V), an inborn error of muscle glycogenolysis, by manipulating free fatty acid availability for oxidation during exercise. Randomized, placebo-controlled, crossover trial. Hospitalized care. Ten patients (8 men and 2 women) with McArdle disease. Patients cycled at a constant workload corresponding to 70% of their maximum oxygen consumption. In random order and on separate days, patients received nicotinic acid (a known blocker of lipolysis) to decrease the availability of free fatty acids or 20% Intralipid infusion to increase free fatty acid availability during exercise. Results were compared with placebo (isotonic sodium chloride solution infusion) and glucose infusion trials. Exercise tolerance was assessed by heart rate response to exercise during different infusions. Free fatty acid levels more than tripled by Intralipid infusion and were halved by nicotinic acid administration. Heart rate was significantly higher during exercise in the Intralipid infusion and nicotinic acid trials compared with the placebo and glucose infusion trials, an effect that was observed before and after the patients had experienced the second wind phenomenon. Lipids are an important source of fuel for exercising muscle in McArdle disease, but maximal rates of fat oxidation seem limited and cannot be increased above physiologically normal rates during exercise. This limitation is probably caused by a metabolic bottleneck in the tricarboxylic acid cycle due to impaired glycolytic flux in McArdle disease. Therapies aimed at enhancing fat use in McArdle disease should be combined with interventions targeting expansion of the tricarboxylic acid cycle.

Changes in force, surface and motor unit EMG during post-exercise development of low frequency fatigue in vastus lateralis muscle.

PubMed

de Ruiter, C J; Elzinga, M J H; Verdijk, P W L; van Mechelen, W; de Haan, A

2005-08-01

We investigated the effects of low frequency fatigue (LFF) on post-exercise changes in rectified surface EMG (rsEMG) and single motor unit EMG (smuEMG) in vastus lateralis muscle (n = 9). On two experimental days the knee extensors were fatigued with a 60-s-isometric contraction (exercise) at 50% maximal force capacity (MFC). On the first day post-exercise (15 s, 3, 9, 15, 21 and 27 min) rsEMG and electrically-induced (surface stimulation) forces were investigated. SmuEMG was obtained on day two. During short ramp and hold (5 s) contractions at 50% MFC, motor unit discharges of the same units were followed over time. Post-exercise MFC and tetanic force (100 Hz stimulation) recovered to about 90% of the pre-exercise values, but recovery with 20 Hz stimulation was less complete: the 20-100 Hz force ratio (mean +/- SD) decreased from 0.65+/-0.06 (pre-exercise) to 0.56+/-0.04 at 27 min post-exercise (P<0.05), indicative of LFF. At 50% MFC, pre-exercise rsEMG (% pre-exercise maximum) and motor unit discharge rate were 51.1 +/- 12.7% and 14.1 +/- 3.7 (pulses per second; pps) respectively, 15 s post-exercise the respective values were 61.4 +/- 15.4% (P<0.05) and 13.2 +/- 5.6 pps (P>0.05). Thereafter, rsEMG (at 50% MFC) remained stable but motor unit discharge rate significantly increased to 17.7 +/- 3.9 pps 27 min post-exercise. The recruitment threshold decreased (P<0.05) from 27.7 +/- 6.6% MFC before exercise to 25.2 +/- 6.7% 27 min post-exercise. The increase in discharge rate was significantly greater than could be expected from the decrease in recruitment threshold. Thus, post-exercise LFF was compensated by increased motor unit discharge rates which could only partly be accounted for by the small decrease in motor unit recruitment threshold.

Assessing cutoff values for increased exercise blood pressure to predict incident hypertension in a general population.

PubMed

Lorbeer, Roberto; Ittermann, Till; Völzke, Henry; Gläser, Sven; Ewert, Ralf; Felix, Stephan B; Dörr, Marcus

2015-07-01

Cutoff values for increased exercise blood pressure (BP) are not established in hypertension guidelines. The aim of the study was to assess optimal cutoff values for increased exercise BP to predict incident hypertension. Data of 661 normotensive participants (386 women) aged 25-77 years from the Study of Health in Pomerania (SHIP-1) with a 5-year follow-up were used. Exercise BP was measured at a submaximal level of 100 W and at maximum level of a symptom-limited cycle ergometry test. Cutoff values for increased exercise BP were defined at the maximum sum of sensitivity and specificity for the prediction of incident hypertension. The area under the receiver-operating characteristic curve (AUC) and net reclassification index (NRI) were calculated to investigate whether increased exercise BP adds predictive value for incident hypertension beyond established cardiovascular risk factors. In men, values of 160  mmHg (100  W level; AUC = 0.7837; NRI = 0.534, P < 0.001) and 210  mmHg (maximum level; AUC = 0.7677; NRI = 0.340, P = 0.003) were detected as optimal cutoff values for the definition of increased exercise SBP. A value of 190  mmHg (AUC = 0.8347; NRI = 0.519, P < 0.001) showed relevance for the definition of increased exercise SBP in women at the maximum level. According to our analyses, 190 and 210  mmHg are clinically relevant cutoff values for increased exercise SBP at the maximum exercise level of cycle ergometry test for women and men, respectively. In addition, for men, our analyses provided a cutoff value of 160  mmHg for increased exercise SBP at the 100  W level.

Comparison of trunk kinematics in trunk training exercises and throwing.

PubMed

Stodden, David F; Campbell, Brian M; Moyer, Todd M

2008-01-01

Strength and conditioning professionals, as well as coaches, have emphasized the importance of training the trunk and the benefits it may have on sport performance and reducing the potential for injury. However, no data on the efficacy of trunk training support such claims. The purpose of this study was to examine the maximum differential trunk rotation and maximum angular velocities of the pelvis and upper torso of participants while they performed 4 trunk exercises (seated band rotations, cross-overs, medicine ball throws, and twisters) and compare these trunk exercise kinematics with the trunk kinematics demonstrated in actual throwing performance. Nine NCAA Division I baseball players participated in this study. Each participant's trunk kinematics was analyzed while he performed 5 repetitions of each exercise in both dominant and nondominant rotational directions. Results indicated maximum differentiated rotation in all 4 trunk exercises was similar to maximum differentiated rotation (approximately 50-60 degrees) demonstrated in throwing performance. Maximum angular velocities of the pelvis and upper torso in the trunk exercises were appreciably slower (approximately 50% or less) than the angular velocities demonstrated during throwing performance. Incorporating trunk training exercises that demonstrate sufficient trunk ranges of motion and velocities into a strength and conditioning program may help to increase ball velocity and/or decrease the risk injury.

[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.

The influence of training characteristics on the effect of aerobic exercise training in patients with chronic heart failure: A meta-regression analysis.

PubMed

Vromen, T; Kraal, J J; Kuiper, J; Spee, R F; Peek, N; Kemps, H M

2016-04-01

Although aerobic exercise training has shown to be an effective treatment for chronic heart failure patients, there has been a debate about the design of training programs and which training characteristics are the strongest determinants of improvement in exercise capacity. Therefore, we performed a meta-regression analysis to determine a ranking of the individual effect of the training characteristics on the improvement in exercise capacity of an aerobic exercise training program in chronic heart failure patients. We focused on four training characteristics; session frequency, session duration, training intensity and program length, and their product; total energy expenditure. A systematic literature search was performed for randomized controlled trials comparing continuous aerobic exercise training with usual care. Seventeen unique articles were included in our analysis. Total energy expenditure appeared the only training characteristic with a significant effect on improvement in exercise capacity. However, the results were strongly dominated by one trial (HF-action trial), accounting for 90% of the total patient population and showing controversial results compared to other studies. A repeated analysis excluding the HF-action trial confirmed that the increase in exercise capacity is primarily determined by total energy expenditure, followed by session frequency, session duration and session intensity. These results suggest that the design of a training program requires high total energy expenditure as a main goal. Increases in training frequency and session duration appear to yield the largest improvement in exercise capacity. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

The effect of cooling prior to and during exercise on exercise performance and capacity in the heat: a meta-analysis.

PubMed

Tyler, Christopher James; Sunderland, Caroline; Cheung, Stephen S

2015-01-01

Exercise is impaired in hot, compared with moderate, conditions. The development of hyperthermia is strongly linked to the impairment and as a result various strategies have been investigated to combat this condition. This meta-analysis focused on the most popular strategy: cooling. Precooling has received the most attention but recently cooling applied during the bout of exercise has been investigated and both were reviewed. We conducted a literature search and retrieved 28 articles which investigated the effect of cooling administered either prior to (n=23) or during (n=5) an exercise test in hot (wet bulb globe temperature >26°C) conditions. Mean and weighted effect size (Cohen's d) were calculated. Overall, precooling has a moderate (d=0.73) effect on subsequent performance but the magnitude of the effect is dependent on the nature of the test. Sprint performance is impaired (d=-0.26) but intermittent performance and prolonged exercise are both improved following cooling (d=0.47 and d=1.91, respectively). Cooling during exercise has a positive effect on performance and capacity (d=0.76). Improvements were observed in studies with and without cooling-induced physiological alterations, and the literature supports the suggestion of a dose-response relationship among cooling, thermal strain and improvements in performance and capacity. In summary, precooling can improve subsequent intermittent and prolonged exercise performance and capacity in a hot environment but sprint performance is impaired. Cooling during exercise also has a positive effect on exercise performance and capacity in a hot environment. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

L-Arginine supplementation improves antioxidant defenses through L-arginine/nitric oxide pathways in exercised rats.

PubMed

Shan, Lingling; Wang, Bin; Gao, Guizhen; Cao, Wengen; Zhang, Yunkun

2013-10-15

l-Arginine (l-Arg) supplementation has been shown to enhance physical exercise capacity and delay onset of fatigue. This work investigated the potential beneficial mechanism(s) of l-Arg supplementation by examining its effect on the cellular oxidative and nitrosative stress pathways in the exercised rats. Forty-eight rats were randomly divided into six groups: sedentary control; sedentary control with l-Arg treatment; endurance training (daily swimming training for 8 wk) control; endurance training with l-Arg treatment; an exhaustive exercise (one time swimming to fatigue) control; and an exhaustive exercise with l-Arg treatment. l-Arg (500 mg/kg body wt) or saline was given to rats by intragastric administration 1 h before the endurance training and the exhaustive swimming test. Expression levels and activities of the l-Arg/nitric oxide (NO) pathway components and parameters of the oxidative stress and antioxidant defense capacity were investigated in l-Arg-treated and control rats. The result show that the l-Arg supplementation completely reversed the exercise-induced activation of NO synthase and superoxide dismutase, increased l-Arg transport capacity, and increased NO and anti-superoxide anion levels. These data demonstrate that l-Arg supplementation effectively reduces the exercise-induced imbalance between oxidative stress and antioxidant defense capacity, and this modulation is likely mediated through the l-Arg/NO pathways. The findings of this study improved our understanding of how l-Arg supplementation prevents elevations of reactive oxygen species and favorably enhances the antioxidant defense capacity during physical exercise.

Relationship of fatigue and exercise capacity with emotional and physical state in patients with coronary artery disease admitted for rehabilitation program.

PubMed

Bunevicius, Adomas; Stankus, Albinas; Brozaitiene, Julija; Girdler, Susan S; Bunevicius, Robertas

2011-08-01

The relationship between subjective fatigue, exercise capacity, and symptoms of depression and anxiety in patients with coronary artery disease (CAD) needs to be specified. In this cross-sectional study, a total of 1,470 (64% men; mean age 57 ± 11 years) consecutive CAD patients admitted for cardiac rehabilitation after treatment of acute cardiac events were evaluated for demographic characteristics, for past and current diagnosis and treatment, for New York Heart Association (NYHA) class, for symptoms of depression and for symptoms of anxiety using the Hospital Anxiety and Depression Scale, and for subjective fatigue using the Multidimensional Fatigue Inventory. On the next day, all patients underwent exercise capacity evaluation using a standard bicycle ergometer testing procedure. In univariate regression analyses, there was the strongest positive association between scores on all Multidimensional Fatigue Inventory subscales and scores on the Hospital Anxiety and Depression Scale depression and anxiety subscales and between exercise capacity and NYHA class. Multivariate regression analyses revealed that symptoms of depression were the strongest positive determinants of all dimensions of subjective fatigue and, together with other significant variables, accounted for 17% to 29% of the variance. However, neither depressive nor anxious symptoms were significant determinants of exercise capacity. The association between subjective fatigue and exercise capacity and vice versa was minimal. Subjective fatigue in CAD patients is strongly related to symptoms of depression and symptoms of anxiety. In contrast, exercise capacity in CAD patients is strongly related to NYHA functional class, with no relationship to symptoms of depression and anxiety. Copyright © 2011 Mosby, Inc. All rights reserved.

Effects of aerobic training combined with respiratory muscle stretching on the functional exercise capacity and thoracoabdominal kinematics in patients with COPD: a randomized and controlled trial.

PubMed

Wada, Juliano T; Borges-Santos, Erickson; Porras, Desiderio Cano; Paisani, Denise M; Cukier, Alberto; Lunardi, Adriana C; Carvalho, Celso Rf

2016-01-01

Patients with COPD present a major recruitment of the inspiratory muscles, predisposing to chest incoordination, increasing the degree of dyspnea and impairing their exercise capacity. Stretching techniques could decrease the respiratory muscle activity and improve their contractile capacity; however, the systemic effects of stretching remain unknown. The aim of this study was to evaluate the effects of aerobic training combined with respiratory muscle stretching on functional exercise capacity and thoracoabdominal kinematics in patients with COPD. This study was a randomized and controlled trial. A total of 30 patients were allocated to a treatment group (TG) or a control group (CG; n=15, each group). The TG was engaged in respiratory muscle stretching and the CG in upper and lower limb muscle stretching. Both groups performed 24 sessions (twice a week, 12 weeks) of aerobic training. Functional exercise capacity (6-minute walk test), thoracoabdominal kinematics (optoelectronic plethysmography), and respiratory muscle activity (surface electromyography) were evaluated during exercise. Analysis of covariance was used to compare the groups at a significance level of 5%. After the intervention, the TG showed improved abdominal (ABD) contribution, compartmental volume, mobility, and functional exercise capacity with decreased dyspnea when compared with the CG ( P <0.01). The TG also showed a decreased respiratory muscle effort required to obtain the same pulmonary volume compared to the CG ( P <0.001). Our results suggest that aerobic training combined with respiratory muscle stretching increases the functional exercise capacity with decreased dyspnea in patients with COPD. These effects are associated with an increased efficacy of the respiratory muscles and participation of the ABD compartment.

Motor Skills and Exercise Capacity Are Associated with Objective Measures of Cognitive Functions and Academic Performance in Preadolescent Children.

PubMed

Geertsen, Svend Sparre; Thomas, Richard; Larsen, Malte Nejst; Dahn, Ida Marie; Andersen, Josefine Needham; Krause-Jensen, Matilde; Korup, Vibeke; Nielsen, Claus Malta; Wienecke, Jacob; Ritz, Christian; Krustrup, Peter; Lundbye-Jensen, Jesper

2016-01-01

To investigate associations between motor skills, exercise capacity and cognitive functions, and evaluate how they correlate to academic performance in mathematics and reading comprehension using standardised, objective tests. This cross-sectional study included 423 Danish children (age: 9.29±0.35 years, 209 girls). Fine and gross motor skills were evaluated in a visuomotor accuracy-tracking task, and a whole-body coordination task, respectively. Exercise capacity was estimated from the Yo-Yo intermittent recovery level 1 children's test (YYIR1C). Selected tests from the Cambridge Neuropsychological Test Automated Battery (CANTAB) were used to assess different domains of cognitive functions, including sustained attention, spatial working memory, episodic and semantic memory, and processing speed. Linear mixed-effects models were used to investigate associations between these measures and the relationship with standard tests of academic performance in mathematics and reading comprehension. Both fine and gross motor skills were associated with better performance in all five tested cognitive domains (all P<0.001), whereas exercise capacity was only associated with better sustained attention (P<0.046) and spatial working memory (P<0.038). Fine and gross motor skills (all P<0.001), exercise capacity and cognitive functions such as working memory, episodic memory, sustained attention and processing speed were all associated with better performance in mathematics and reading comprehension. The data demonstrate that fine and gross motor skills are positively correlated with several aspects of cognitive functions and with academic performance in both mathematics and reading comprehension. Moreover, exercise capacity was associated with academic performance and performance in some cognitive domains. Future interventions should investigate associations between changes in motor skills, exercise capacity, cognitive functions, and academic performance to elucidate the causality of these associations.

Motor Skills and Exercise Capacity Are Associated with Objective Measures of Cognitive Functions and Academic Performance in Preadolescent Children

PubMed Central

Thomas, Richard; Larsen, Malte Nejst; Dahn, Ida Marie; Andersen, Josefine Needham; Krause-Jensen, Matilde; Korup, Vibeke; Nielsen, Claus Malta; Wienecke, Jacob; Ritz, Christian; Krustrup, Peter; Lundbye-Jensen, Jesper

2016-01-01

Objective To investigate associations between motor skills, exercise capacity and cognitive functions, and evaluate how they correlate to academic performance in mathematics and reading comprehension using standardised, objective tests. Methods This cross-sectional study included 423 Danish children (age: 9.29±0.35 years, 209 girls). Fine and gross motor skills were evaluated in a visuomotor accuracy-tracking task, and a whole-body coordination task, respectively. Exercise capacity was estimated from the Yo-Yo intermittent recovery level 1 children's test (YYIR1C). Selected tests from the Cambridge Neuropsychological Test Automated Battery (CANTAB) were used to assess different domains of cognitive functions, including sustained attention, spatial working memory, episodic and semantic memory, and processing speed. Linear mixed-effects models were used to investigate associations between these measures and the relationship with standard tests of academic performance in mathematics and reading comprehension. Results Both fine and gross motor skills were associated with better performance in all five tested cognitive domains (all P<0.001), whereas exercise capacity was only associated with better sustained attention (P<0.046) and spatial working memory (P<0.038). Fine and gross motor skills (all P<0.001), exercise capacity and cognitive functions such as working memory, episodic memory, sustained attention and processing speed were all associated with better performance in mathematics and reading comprehension. Conclusions The data demonstrate that fine and gross motor skills are positively correlated with several aspects of cognitive functions and with academic performance in both mathematics and reading comprehension. Moreover, exercise capacity was associated with academic performance and performance in some cognitive domains. Future interventions should investigate associations between changes in motor skills, exercise capacity, cognitive functions, and academic performance to elucidate the causality of these associations. PMID:27560512

Effects of aerobic training combined with respiratory muscle stretching on the functional exercise capacity and thoracoabdominal kinematics in patients with COPD: a randomized and controlled trial

PubMed Central

Wada, Juliano T; Borges-Santos, Erickson; Porras, Desiderio Cano; Paisani, Denise M; Cukier, Alberto; Lunardi, Adriana C; Carvalho, Celso RF

2016-01-01

Background Patients with COPD present a major recruitment of the inspiratory muscles, predisposing to chest incoordination, increasing the degree of dyspnea and impairing their exercise capacity. Stretching techniques could decrease the respiratory muscle activity and improve their contractile capacity; however, the systemic effects of stretching remain unknown. Objective The aim of this study was to evaluate the effects of aerobic training combined with respiratory muscle stretching on functional exercise capacity and thoracoabdominal kinematics in patients with COPD. Design This study was a randomized and controlled trial. Participants A total of 30 patients were allocated to a treatment group (TG) or a control group (CG; n=15, each group). Intervention The TG was engaged in respiratory muscle stretching and the CG in upper and lower limb muscle stretching. Both groups performed 24 sessions (twice a week, 12 weeks) of aerobic training. Evaluations Functional exercise capacity (6-minute walk test), thoracoabdominal kinematics (optoelectronic plethysmography), and respiratory muscle activity (surface electromyography) were evaluated during exercise. Analysis of covariance was used to compare the groups at a significance level of 5%. Results After the intervention, the TG showed improved abdominal (ABD) contribution, compartmental volume, mobility, and functional exercise capacity with decreased dyspnea when compared with the CG (P<0.01). The TG also showed a decreased respiratory muscle effort required to obtain the same pulmonary volume compared to the CG (P<0.001). Conclusion Our results suggest that aerobic training combined with respiratory muscle stretching increases the functional exercise capacity with decreased dyspnea in patients with COPD. These effects are associated with an increased efficacy of the respiratory muscles and participation of the ABD compartment. PMID:27822031

Five months of physical exercise in hemodialysis patients: effects on aerobic capacity, physical function and self-rated health.

PubMed

Molsted, Stig; Eidemak, Inge; Sorensen, Helle Tauby; Kristensen, Jens Halkjaer

2004-01-01

The number of chronic renal failure patients treated by hemodialysis (HD) is continuously increasing. Most patients have reduced physical capacity and have a high risk of cardiac and vascular diseases. The aim of this study was to determine the effects of 5 months physical exercise of HD patients' physical capacity, self-rated health and risk factors for cardiovascular disease. 33 HD patients were included in the study. HD for more than 3 months, age >18 years. Diabetes mellitus, symptomatic cardiovascular disease, musculoskeletal limitations, severe peripheral polyneuropathy, inability to speak Danish or English, dementia or other mental disorders. The patients were randomly assigned to an exercise group (EG, n = 22) or a control group (CG, n = 11). Prior to randomization, baseline testing was performed. The effects were measured by aerobic capacity, '2-min stair climbing', 'squat test', self-rated health (SF36), blood pressure and lipids. All tests were carried out by blinded testers. The intervention consisted of 1 h of physical exercise twice a week for 5 months. 20 patients completed the intervention. Attendance was 74% of all sessions. There were no dropouts caused by complications related to the intervention. The EG had a significant increase in aerobic capacity, 'squat test' and Physical Function and Physical Component Scale (SF36). No significant changes were observed in any of the parameters in the CG. Physical exercise twice a week for 5 months increases physical function and aerobic capacity in HD patients. An exercise program with only two exercise sessions per week seems easy to implement in clinical practice with high attendance among participants. Further investigation is needed to determine the effects on blood pressure and lipids. There were no medical complications related to the exercise program. Copyright 2004 S. Karger AG, Basel

The use of aerobic exercise training in improving aerobic capacity in individuals with stroke: a meta-analysis

PubMed Central

Pang, Marco YC; Eng, Janice J; Dawson, Andrew S; Gylfadóttir, Sif

2011-01-01

Objective To determine whether aerobic exercise improves aerobic capacity in individuals with stroke. Design A systematic review of randomized controlled trials. Databases searched MEDLINE, CINAHL, EMBASE, Cochrane Database of Systematic Reviews, Physiotherapy Evidence Database were searched. Inclusion criteria Design: randomized controlled trials; Participants: individuals with stroke; Interventions: aerobic exercise training aimed at improving aerobic capacity; Outcomes Primary outcomes: aerobic capacity [peak oxygen consumption (VO2), peak workload); Secondary outcomes: walking velocity, walking endurance. Data Analysis The methodological quality was assessed by the PEDro scale. Meta-analyses were performed for all primary and secondary outcomes. Results Nine articles (seven RCTs) were identified. The exercise intensity ranged from 50% to 80% heart rate reserve. Exercise duration was 20–40 minutes for 3–5 days a week. The total number of subjects included in the studies was 480. All studies reported positive effects on aerobic capacity, regardless of the stage of stroke recovery. Meta-analysis revealed a significant homogeneous standardized effect size (SES) in favour of aerobic exercise to improve peak VO2 (SES, 0.42; 95%CI, 0.15 to 0.69; p=0.001) and peak workload (SES, 0.50; 95%CI, 0.26 to 0.73; p<0.001). There was also a significant homogeneous SES in favour of aerobic training to improve walking velocity (SES, 0.26; 95%CI, 0.05 to 0.48; p=0.008) and walking endurance (SES, 0.30; 95%CI, 0.06to 0.55; p=0.008). Conclusions There is good evidence that aerobic exercise is beneficial for improving aerobic capacity in people with mild and moderate stroke. Aerobic exercise should be an important component of stroke rehabilitation. PMID:16541930

Exercise science: research to sustain and enhance performance

NASA Astrophysics Data System (ADS)

Wingo, Jonathan E.

2013-05-01

Cardiovascular adjustments accompanying exercise in high ambient temperatures are likely responsible for diminished aerobic capacity and performance in such conditions. These adjustments include a phenomenon known as cardiovascular drift in which heart rate rises and stroke volume declines progressively over time during constant-rate exercise. A variety of factors modulate the magnitude of cardiovascular drift, e.g., elevated core and skin temperatures, dehydration, and exercise intensity. Regardless of the mode of manipulation, decreases in stroke volume associated with cardiovascular drift result in directionally and proportionally similar decreases in maximal aerobic capacity. Maximal aerobic capacity is determined by maximal heart rate, maximal tissue oxygen extraction, and maximal stroke volume. Because maximal heart rate and maximal tissue oxygen extraction are unaffected during exercise in the heat, decreased stroke volume associated with cardiovascular drift likely persists during maximal efforts and explains the decrease in maximal aerobic capacity. Decreased maximal aerobic capacity results in a greater perceptual and physiological strain accompanying any given level of work. Therefore, sustaining and enhancing performance involves sophisticated monitoring of physiological strain combined with development of countermeasures that mitigate the magnitude of deleterious phenomena like cardiovascular drift.

The Yo-Yo IR2 test: physiological response, reliability, and application to elite soccer.

PubMed

Oberacker, Lisa M; Davis, Shala E; Haff, G Gregory; Witmer, Chad A; Moir, Gavin L

2012-10-01

The purpose of this study was to compare the effects of resistance training performed on either a stable or unstable surface on performance tests in female soccer players. Nineteen National Collegiate Athletic Association Division II female soccer players were assigned to either an unstable training group (UST: 19.0 ± 0.47 years; 1.69 ± 6.4 m; 67.8 ± 7.7 kg) or a stable training group (ST: 19.6 ± 0.49 years; 1.64 ± 3.2 m; 62.7 ± 6.27 kg). Player positions were distributed evenly between the groups. Both the groups followed a 5-week periodized resistance training program designed to develop maximum muscular strength. The groups performed the same exercises during each workout, with the UST performing 2 of the exercises in each session on an unstable surface. Pretraining and posttraining measures of straight-line sprint speed, planned and reactive agility, aerobic capacity, and countermovement vertical jump (CMJ) were taken. Significant main effects for time were reported for straight-line sprint speed, planned agility, and reactive agility with both groups demonstrating improvements during the posttraining testing session. The ST demonstrated a significant increase in CMJ during the posttraining session (change in mean: 0.04 m) in contrast to the decline demonstrated by the UST (change in mean: -0.01 m). Performing resistance training exercises on an unstable surface confers no advantage over traditional resistance training exercises for improving the speed, agility, and aerobic capacity of female soccer players. Furthermore, the use of an unstable surface may inhibit the effects of resistance training on vertical jump height, an important variable in soccer performance.

Original Research: ACE2 activator associated with physical exercise potentiates the reduction of pulmonary fibrosis

PubMed Central

Prata, Luana O; Rodrigues, Carolina R; Martins, Jéssica M; Vasconcelos, Paula C; Oliveira, Fabrício Marcus S; Ferreira, Anderson J; Rodrigues-Machado, Maria da Glória

2016-01-01

The interstitial lung diseases are poorly understood and there are currently no studies evaluating the association of physical exercise with an ACE2 activator (DIZE) as a possible treatment for this group of diseases. We evaluate the effects of pharmacological treatment with an angiotensin-converting enzyme 2 activator drug, associated with exercise, on the pulmonary lesions induced by bleomycin. From the 96 male Balb/c mice used in the experiment, only 49 received 8 U/kg of bleomycin (BLM, intratracheally). The mice were divided into control (C) and bleomycin (BLM) groups, sedentary and trained (C-SED, C-EXE, BLM-SED, BLM-EXE), control and bleomycin and also sedentary and trained treated with diminazene (C-SED/E, C-EXE/E, BLM-SED/E, BLM-EXE/E). The animals were trained five days/week, 1 h/day with 60% of the maximum load obtained in a functional capacity test, for four weeks. Diminazene groups were treated (1 mg/kg, by gavage) daily until the end of the experiment. The lungs were collected 48 h after the training program, set in buffered formalin and investigated by Gomori’s trichrome, immunohistochemistry of collagen type I, TGF-β1, beta-prolyl-4-hydroxylase, MMP-1 and -2. The BLM-EXE/E group obtained a significant increase in functional capacity, reduced amount of fibrosis and type I collagen, decreased expression of TGF-β1 and beta-prolyl-4-hydroxylase and an increase of metalloproteinase −1, −2 when compared with the other groups. The present research shows, for the first time, that exercise training associated with the activation of ACE2 potentially reduces pulmonary fibrosis. PMID:27550926

Maximal metabolic rates during voluntary exercise, forced exercise, and cold exposure in house mice selectively bred for high wheel-running.

PubMed

Rezende, Enrico L; Chappell, Mark A; Gomes, Fernando R; Malisch, Jessica L; Garland, Theodore

2005-06-01

Selective breeding for high wheel-running activity has generated four lines of laboratory house mice (S lines) that run about 170% more than their control counterparts (C lines) on a daily basis, mostly because they run faster. We tested whether maximum aerobic metabolic rates (V(O2max)) have evolved in concert with wheel-running, using 48 females from generation 35. Voluntary activity and metabolic rates were measured on days 5+6 of wheel access (mimicking conditions during selection), using wheels enclosed in metabolic chambers. Following this, V(O2max) was measured twice on a motorized treadmill and twice during cold-exposure in a heliox atmosphere (HeO2). Almost all measurements, except heliox V(O2max), were significantly repeatable. After accounting for differences in body mass (S < C) and variation in age at testing, S and C did not differ in V(O2max) during forced exercise or in heliox, nor in maximal running speeds on the treadmill. However, running speeds and V(O2max) during voluntary exercise were significantly higher in S lines. Nevertheless, S mice never voluntarily achieved the V(O2max) elicited during their forced treadmill trials, suggesting that aerobic capacity per se is not limiting the evolution of even higher wheel-running speeds in these lines. Our results support the hypothesis that S mice have genetically higher motivation for wheel-running and they demonstrate that behavior can sometimes evolve independently of performance capacities. We also discuss the possible importance of domestication as a confounding factor to extrapolate results from this animal model to natural populations.

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.

l-Carnitine Supplementation in Recovery after Exercise.

PubMed

Fielding, Roger; Riede, Linda; Lugo, James P; Bellamine, Aouatef

2018-03-13

Given its pivotal role in fatty acid oxidation and energy metabolism, l-carnitine has been investigated as ergogenic aid for enhancing exercise capacity in the healthy athletic population. Early research indicates its beneficial effects on acute physical performance, such as increased maximum oxygen consumption and higher power output. Later studies point to the positive impact of dietary supplementation with l-carnitine on the recovery process after exercise. It is demonstrated that l-carnitine alleviates muscle injury and reduces markers of cellular damage and free radical formation accompanied by attenuation of muscle soreness. The supplementation-based increase in serum and muscle l-carnitine contents is suggested to enhance blood flow and oxygen supply to the muscle tissue via improved endothelial function thereby reducing hypoxia-induced cellular and biochemical disruptions. Studies in older adults further showed that l-carnitine intake can lead to increased muscle mass accompanied by a decrease in body weight and reduced physical and mental fatigue. Based on current animal studies, a role of l-carnitine in the prevention of age-associated muscle protein degradation and regulation of mitochondrial homeostasis is suggested.

l-Carnitine Supplementation in Recovery after Exercise

PubMed Central

Fielding, Roger; Riede, Linda; Lugo, James P.; Bellamine, Aouatef

2018-01-01

Given its pivotal role in fatty acid oxidation and energy metabolism, l-carnitine has been investigated as ergogenic aid for enhancing exercise capacity in the healthy athletic population. Early research indicates its beneficial effects on acute physical performance, such as increased maximum oxygen consumption and higher power output. Later studies point to the positive impact of dietary supplementation with l-carnitine on the recovery process after exercise. It is demonstrated that l-carnitine alleviates muscle injury and reduces markers of cellular damage and free radical formation accompanied by attenuation of muscle soreness. The supplementation-based increase in serum and muscle l-carnitine contents is suggested to enhance blood flow and oxygen supply to the muscle tissue via improved endothelial function thereby reducing hypoxia-induced cellular and biochemical disruptions. Studies in older adults further showed that l-carnitine intake can lead to increased muscle mass accompanied by a decrease in body weight and reduced physical and mental fatigue. Based on current animal studies, a role of l-carnitine in the prevention of age-associated muscle protein degradation and regulation of mitochondrial homeostasis is suggested. PMID:29534031

[Effect of exhaustive weightlifting exercise on EMG, biochemical markers of muscle damage and performance capacity in young male subjects].

PubMed

Minigalin, A D; Shumakov, A R; Novozhilov, A V; Samsonova, A V; Kos'mina, E A; Kalinskiĭ, M I; Baranova, T I; Kubasov, I V; Morozov, V I

2015-01-01

The aim of this study was to examine the effect of exhaustive weightlifting exercise on electrical and biochemical variables and performance capacity in young male subjects. The onset of exercise (80-50% 1RM) was associated with a decrease in the amount of work performed, which was followed by a steady performance capacity at 40-10% 1RM. There were no significant changes of m. rectus femoris EMG maximal amplitude though it tended to be increased during the first half of exercise. A significant blood lactate concentration increase indicated that an anaerobic metabolism was a predominant mechanism of muscle contraction energy-supply. CK level in blood plasma did not change but plasma myoglobin concentration doubled immediately post-exercise. The data presented here suggest that decrease in performance capacity was likely due to progressive "refusal of work" of the fast motor units and work prolongation of weaker, intermediate and slow motor units. Unchangeable CK activity and relatively small increase in myoglobin concentration in plasma suggest that used weightlifting exercise did not induced substantial damage in myocytes' membranes in our subjects.

Effects of rehydration and food consumption on salivary flow, pH and buffering capacity in young adult volunteers during ergometer exercise.

PubMed

Tanabe, Mai; Takahashi, Toshiyuki; Shimoyama, Kazuhiro; Toyoshima, Yukako; Ueno, Toshiaki

2013-10-28

The aim of this study was to investigate the influences of rehydration and food consumption on salivary flow, pH, and buffering capacity during bicycle ergometer exercise in participants. Ten healthy volunteers exercised on a bicycle ergometer at 80% of their maximal heart rate. These sessions lasted for two periods of 20 min separated by 5-min rest intervals. Volunteers were subjected to one of the following conditions: (1) no water (mineral water) or food consumption, (2) only water for rehydration, (3) water and food consumption, (4) a sports drink only for rehydration, and (5) rehydration with a sports drink and food. Statistical significance was assessed using one-way analysis of variance and Dunnett's test (p < 0.05). The salivary pH decreased significantly during and after exercise in conditions 4 and 5. The salivary buffering capacity decreased significantly during exercise and/or after the exercise in conditions 1, 3, 4, and 5. The results showed that salivary pH and buffering capacity decreased greatly depending on the combination of a sports drink and food.

Exercise capacity before and after an 8-week multidisciplinary inpatient rehabilitation program in lung cancer patients: a pilot study.

PubMed

Spruit, Martijn A; Janssen, Paul P; Willemsen, Sonja C P; Hochstenbag, Monique M H; Wouters, Emiel F M

2006-05-01

Although lung cancer is a highly prevalent type of cancer, the effects of an inpatient multidisciplinary rehabilitation program on pulmonary function and exercise capacity have never been studied in these patients. Pulmonary function, 6-min walking distance and peak exercise capacity of 10 patients with a severely impaired pulmonary function following treatment of lung cancer were assessed in this pilot study before and after an 8-week inpatient multidisciplinary rehabilitation program. At baseline, patients had a restrictive pulmonary function and an apparent exercise intolerance (median 6-min walking distance: 63.6% predicted; median peak cycling load: 58.5% predicted). Despite the lack of change in median pulmonary function [FEV1: -0.01L, p = 0.5469], functional exercise capacity [145 m; 43.2% of the initial values, p=0.0020] and peak exercise capacity [26 W; 34.4% of the initial values, p = 0.0078] improved significantly compared to baseline. Future trials have to corroborate the present findings. Nevertheless, patients with lung cancer have a clear indication to start a comprehensive rehabilitation program following intensive treatment of their disease. In fact, based on the results of the present pilot study it appears that these patients are good candidates for pulmonary rehabilitation programs.

[The maximum heart rate in the exercise test: the 220-age formula or Sheffield's table?].

PubMed

Mesquita, A; Trabulo, M; Mendes, M; Viana, J F; Seabra-Gomes, R

1996-02-01

To determine in the maximum cardiac rate in exercise test of apparently healthy individuals may be more properly estimated through 220-age formula (Astrand) or the Sheffield table. Retrospective analysis of clinical history and exercises test of apparently healthy individuals submitted to cardiac check-up. Sequential sampling of 170 healthy individuals submitted to cardiac check-up between April 1988 and September 1992. Comparison of maximum cardiac rate of individuals studied by the protocols of Bruce and modified Bruce, in interrupted exercise test by fatigue, and with the estimated values by the formulae: 220-age versus Sheffield table. The maximum cardiac heart rate is similar with both protocols. This parameter in normal individuals is better predicted by the 220-age formula. The theoretic maximum cardiac heart rate determined by 220-age formula should be recommended for a healthy, and for this reason the Sheffield table has been excluded from our clinical practice.

Assessment of Pulmonary Capillary Blood Volume, Membrane Diffusing Capacity, and Intrapulmonary Arteriovenous Anastomoses During Exercise.

PubMed

Tedjasaputra, Vincent; van Diepen, Sean; Collins, Sophie É; Michaelchuk, Wade M; Stickland, Michael K

2017-02-20

Exercise is a stress to the pulmonary vasculature. With incremental exercise, the pulmonary diffusing capacity (DLCO) must increase to meet the increased oxygen demand; otherwise, a diffusion limitation may occur. The increase in DLCO with exercise is due to increased capillary blood volume (Vc) and membrane diffusing capacity (Dm). Vc and Dm increase secondary to the recruitment and distension of pulmonary capillaries, increasing the surface area for gas exchange and decreasing pulmonary vascular resistance, thereby attenuating the increase in pulmonary arterial pressure. At the same time, the recruitment of intrapulmonary arteriovenous anastomoses (IPAVA) during exercise may contribute to gas exchange impairment and/or prevent large increases in pulmonary artery pressure. We describe two techniques to evaluate pulmonary diffusion and circulation at rest and during exercise. The first technique uses multiple-fraction of inspired oxygen (FIO2) DLCO breath holds to determine Vc and Dm at rest and during exercise. Additionally, echocardiography with intravenous agitated saline contrast is used to assess IPAVAs recruitment. Representative data showed that the DLCO, Vc, and Dm increased with exercise intensity. Echocardiographic data showed no IPAVA recruitment at rest, while contrast bubbles were seen in the left ventricle with exercise, suggesting exercise-induced IPAVA recruitment. The evaluation of pulmonary capillary blood volume, membrane diffusing capacity, and IPAVA recruitment using echocardiographic methods is useful to characterize the ability of the lung vasculature to adapt to the stress of exercise in health as well as in diseased groups, such as those with pulmonary arterial hypertension and chronic obstructive pulmonary disease.

Assessment of Pulmonary Capillary Blood Volume, Membrane Diffusing Capacity, and Intrapulmonary Arteriovenous Anastomoses During Exercise

PubMed Central

Tedjasaputra, Vincent; van Diepen, Sean; Collins, Sophie É; Michaelchuk, Wade M.; Stickland, Michael K.

2017-01-01

Exercise is a stress to the pulmonary vasculature. With incremental exercise, the pulmonary diffusing capacity (DLCO) must increase to meet the increased oxygen demand; otherwise, a diffusion limitation may occur. The increase in DLCO with exercise is due to increased capillary blood volume (Vc) and membrane diffusing capacity (Dm). Vc and Dm increase secondary to the recruitment and distension of pulmonary capillaries, increasing the surface area for gas exchange and decreasing pulmonary vascular resistance, thereby attenuating the increase in pulmonary arterial pressure. At the same time, the recruitment of intrapulmonary arteriovenous anastomoses (IPAVA) during exercise may contribute to gas exchange impairment and/or prevent large increases in pulmonary artery pressure. We describe two techniques to evaluate pulmonary diffusion and circulation at rest and during exercise. The first technique uses multiple-fraction of inspired oxygen (FIO2) DLCO breath holds to determine Vc and Dm at rest and during exercise. Additionally, echocardiography with intravenous agitated saline contrast is used to assess IPAVAs recruitment. Representative data showed that the DLCO, Vc, and Dm increased with exercise intensity. Echocardiographic data showed no IPAVA recruitment at rest, while contrast bubbles were seen in the left ventricle with exercise, suggesting exercise-induced IPAVA recruitment. The evaluation of pulmonary capillary blood volume, membrane diffusing capacity, and IPAVA recruitment using echocardiographic methods is useful to characterize the ability of the lung vasculature to adapt to the stress of exercise in health as well as in diseased groups, such as those with pulmonary arterial hypertension and chronic obstructive pulmonary disease. PMID:28287506

The influence of training characteristics on the effect of exercise training in patients with coronary artery disease: Systematic review and meta-regression analysis.

PubMed

Kraal, Jos J; Vromen, Tom; Spee, Ruud; Kemps, Hareld M C; Peek, Niels

2017-10-15

Although exercise-based cardiac rehabilitation improves exercise capacity of coronary artery disease patients, it is unclear which training characteristic determines this improvement. Total energy expenditure and its constituent training characteristics (training intensity, session frequency, session duration and programme length) vary considerably among clinical trials, making it hard to compare studies directly. Therefore, we performed a systematic review and meta-regression analysis to assess the effect of total energy expenditure and its constituent training characteristics on exercise capacity. We identified randomised controlled trials comparing continuous aerobic exercise training with usual care for patients with coronary artery disease. Studies were included when training intensity, session frequency, session duration and programme length was described, and exercise capacity was reported in peakVO 2 . Energy expenditure was calculated from the four training characteristics. The effect of training characteristics on exercise capacity was determined using mixed effects linear regression analyses. The analyses were performed with and without total energy expenditure as covariate. Twenty studies were included in the analyses. The mean difference in peakVO 2 between the intervention group and control group was 3.97ml·min -1 ·kg -1 (p<0.01, 95% CI 2.86 to 5.07). Total energy expenditure was significantly related to improvement of exercise capacity (effect size 0.91ml·min -1 ·kg -1 per 100J·kg, p<0.01, 95% CI 0.77 to 1.06), no effect was found for its constituent training characteristics after adjustment for total energy expenditure. We conclude that the design of an exercise programme should primarily be aimed at optimising total energy expenditure rather than on one specific training characteristic. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Relationship Between Post-exercise Heart Rate Recovery and Changing Ratio of Cardiopulmonary Exercise Capacity.

PubMed

Kim, Ji-Hyun; Choe, Yu-Ri; Song, Min-Keun; Choi, In-Sung; Han, Jae-Young

2017-12-01

To determine whether heart rate recovery (HRR) following an exercise tolerance test (ETT) is correlated with a changing ratio of peak oxygen consumption (VO 2 ) and maximal metabolic equivalents (MET max ). A total of 60 acute myocardial infarction (AMI) patients who underwent ETT at both assessment points - 3 weeks (T0) after the AMI attack and 3 months after T0 (T1) were included. After achieving a peak workload, the treadmill was stopped with a 5-minute cooldown period, and the patients recovered in a comfortable and relaxed seated position. HRR was defined as the difference between the maximal heart rate (HR max ) and the HR measured at specific time intervals - immediately after the cool down period (HRR-0) and 3 minutes after the completion of the ETT (HRR-3). HRR-0 and HRR-3 increased over time, whereas VO 2max and MET max did not show significant changes. There was a positive correlation between HRR at T0 and the exercise capacity at T0. HRR at T0 also showed a positive correlation with the exercise capacity at T1. There was no significant correlation between HRR measured at T0 and the change in the ratio of VO 2max and MET max , as calculated by subtracting VO 2max and MET max obtained at T0 from those obtained at T1, divided by VO 2max at T0 and multiplied by 100. Post-exercise HRR measured at 3 weeks after the AMI onset can reflect the exercise capacity 3 months after the first ETT. However, it may be difficult to correlate post-exercise HRR at T0 with the degree of increase in cardiopulmonary exercise capacity in patients with AMI.

Effects of dynamic hyperinflation on exercise capacity and quality of life in stable COPD patients.

PubMed

Zhao, Li; Peng, Liyue; Wu, Baomei; Bu, Xiaoning; Wang, Chen

2016-09-01

Dynamic hyperinflation (DH) is an important pathophysiological characteristic of chronic obstructive pulmonary disease (COPD). There is increasing evidence that DH has negative effects on exercise performance and quality of life. The objective of this study was to explore effects of DH on exercise capacity and quality of life in stable COPD patients. Fifty-eight COPD patients and 20 matched healthy individuals underwent pulmonary function test, 6-min walk test and symptom-limited cardiopulmonary exercise test (CPET). End-expiratory lung volume/total lung capacity ratio (EELVmax/TLC) at peak exercise of CPET was evaluated, and EELVmax/TLC ≥ 75% was defined as 'severe dynamic hyperinflation (SDH)'. Of the 58 patients studied, 29 (50.0%) presented with SDH (SDH+ group, EELVmax/TLC 79.60 ± 3.60%), having worse maximal exercise capacity reflected by lower peakload, maximal oxygen uptake (VO2 max), maximal carbon dioxide output (VCO2 max) and maximal minute ventilation (VEmax) than did those without SDH (SDH- group, EELVmax/TLC 67.44 ± 6.53%). The EELVmax/TLC ratio at peak exercise had no association with variables of pulmonary function and 6-min walk distance (6MWD), but correlated inversely with peakload, VO2 max, VCO2 max and VEmax (r = -0.300~-0.351, P < 0.05). Although no significant differences were observed, patients with EELVmax/TLC ≥ 75% tended to have higher COPD assessment test score (15.07 ± 6.55 vs 13.28 ± 6.59, P = 0.303). DH develops variably during exercise and has a greater impact on maximal exercise capacity than 6MWD, even in those with the same extent of pulmonary function impairment at rest. © 2015 John Wiley & Sons Ltd.

Supervised exercise improves cutaneous reinnervation capacity in metabolic syndrome patients.

PubMed

Singleton, J Robinson; Marcus, Robin L; Lessard, Margaret K; Jackson, Justin E; Smith, A Gordon

2015-01-01

Unmyelinated cutaneous axons are vulnerable to physical and metabolic injury, but also capable of rapid regeneration. This balance may help determine risk for peripheral neuropathy associated with diabetes or metabolic syndrome. Capsaicin application for 48 hours induces cutaneous fibers to die back into the dermis. Regrowth can be monitored by serial skin biopsies to determine intraepidermal nerve fiber density (IENFD). We used this capsaicin axotomy technique to examine the effects of exercise on cutaneous regenerative capacity in the setting of metabolic syndrome. Baseline ankle IENFD and 30-day cutaneous regeneration after thigh capsaicin axotomy were compared for participants with type 2 diabetes (n = 35) or metabolic syndrome (n = 32) without symptoms or examination evidence of neuropathy. Thirty-six participants (17 with metabolic syndrome) then joined twice weekly observed exercise and lifestyle counseling. Axotomy regeneration was repeated in month 4 during this intervention. Baseline distal leg IENFD was significantly reduced for both metabolic syndrome and diabetic groups. With exercise, participants significantly improved exercise capacity and lower extremity power. Following exercise, 30-day reinnervation rate improved (0.051 ± 0.027 fibers/mm/day before vs 0.072 ± 0.030 after exercise, p = 0.002). Those who achieved improvement in more metabolic syndrome features experienced a greater degree of 30-day reinnervation (p < 0.012). Metabolic syndrome was associated with reduced baseline IENFD and cutaneous regeneration capacity comparable to that seen in diabetes. Exercise-induced improvement in metabolic syndrome features increased cutaneous regenerative capacity. The results underscore the potential benefit to peripheral nerve function of a behavioral modification approach to metabolic improvement. © 2014 American Neurological Association.

Breathing exercises with vagal biofeedback may benefit patients with functional dyspepsia.

PubMed

Hjelland, Ina E; Svebak, Sven; Berstad, Arnold; Flatabø, Geir; Hausken, Trygve

2007-09-01

Many patients with functional dyspepsia (FD) have postprandial symptoms, impaired gastric accommodation and low vagal tone. The aim of this study was to improve vagal tone, and thereby also drinking capacity, intragastric volume and quality of life, using breathing exercises with vagal biofeedback. Forty FD patients were randomized to either a biofeedback group or a control group. The patients received similar information and care. Patients in the biofeedback group were trained in breathing exercises, 6 breaths/min, 5 min each day for 4 weeks, using specially designed software for vagal biofeedback. Effect variables included maximal drinking capacity using a drink test (Toro clear meat soup 100 ml/min), intragastric volume at maximal drinking capacity, respiratory sinus arrhythmia (RSA), skin conductance (SC) and dyspepsia-related quality of life scores. Drinking capacity and quality of life improved significantly more in the biofeedback group than in the control group (p=0.02 and p=0.01) without any significant change in baseline autonomic activity (RSA and SC) or intragastric volume. After the treatment period, RSA during breathing exercises was significantly correlated to drinking capacity (r=0.6, p=0.008). Breathing exercises with vagal biofeedback increased drinking capacity and improved quality of life in FD patients, but did not improve baseline vagal tone.

Effects of high-intensity interval training on central haemodynamics and skeletal muscle oxygenation during exercise in patients with chronic heart failure.

PubMed

Spee, Ruud F; Niemeijer, Victor M; Wijn, Pieter F; Doevendans, Pieter A; Kemps, Hareld M

2016-12-01

Background High-intensity interval training (HIT) improves exercise capacity in patients with chronic heart failure (CHF). Moreover, HIT was associated with improved resting cardiac function. However, the extent to which these improvements actually contribute to training-induced changes in exercise capacity remains to be elucidated. Therefore, we evaluated the effects of HIT on exercising central haemodynamics and skeletal muscle oxygenation. Methods Twenty-six CHF patients were randomised to a 12-week 4 × 4 minute HIT program at 85-95% of peak VO 2 or usual care. Patients performed maximal and submaximal cardiopulmonary exercise testing with simultaneous assessment of cardiac output and skeletal muscle oxygenation by near infrared spectroscopy, using the amplitude of the tissue saturation index (TSIamp). Results Peak workload increased by 11% after HIT ( p between group = 0.01) with a non-significant increase in peak VO 2 (+7%, p between group = 0.19). Cardiac reserve increased by 37% after HIT ( p within group = 0.03, p between group = 0.08); this increase was not related to improvements in peak workload. Oxygen uptake recovery kinetics after submaximal exercise were accelerated by 20% ( p between group = 0.02); this improvement was related to a decrease in TSIamp ( r = 0.71, p = 0.03), but not to changes in cardiac output kinetics. Conclusion HIT induced improvements in maximal exercise capacity and exercising haemodynamics at peak exercise. Improvements in recovery after submaximal exercise were associated with attenuated skeletal muscle deoxygenation during submaximal exercise, but not with changes in cardiac output kinetics, suggesting that the effect of HIT on submaximal exercise capacity is mediated by improved microvascular oxygen delivery-to-utilisation matching.

Effect of therapeutic jaw exercise on temporomandibular disorders in individuals with chronic whiplash-associated disorders.

PubMed

Klobas, Luciano; Axelsson, Susanna; Tegelberg, Ake

2006-11-01

The aim of this study was to investigate the effect of a specific therapeutic jaw exercise on the temporomandibular disorders of patients with chronic whiplash-associated disorders. Ninety-four consecutive patients with whiplash-related conditions were referred to and accepted for a treatment period at a center for functional evaluation and rehabilitation during 2001-2002. The patients followed a program of physical therapy, occupational therapy, and pain management. At the start of their stay, they were examined by a physician specialized in rehabilitation medicine and also by a dentist who performed a functional examination of the stomatognathic system. Of the 93 patients who accepted participation in the study, 55 were diagnosed with temporomandibular disorders and chronic whiplash-associated disorders in accordance with the inclusion criteria. They were randomized into a jaw exercise group (n = 25), who performed specific therapeutic jaw exercises, and a control group (n = 30). Both groups undertook the whiplash rehabilitation program at the center. There were no inter- or intra-group differences in symptoms and signs of temporomandibular disorders at baseline, nor at the 3-week and 6-month follow-ups, except for an increase of maximum active mouth-opening capacity in the control group. In conclusion, the therapeutic jaw exercises, in addition to the regular whiplash rehabilitation program, did not reduce symptoms and signs of temporomandibular disorders in patients with chronic whiplash-associated disorders.

Enhanced vagal baroreflex response during 24 h after acute exercise

NASA Technical Reports Server (NTRS)

Convertino, V. A.; Adams, W. C.

1991-01-01

We evaluated carotid-cardiac baroreflex responses in eight normotensive men (25-41 yr) on two different test days, each separated by at least 1 wk. On one day, baroreflex response was tested before and at 3, 6, 12, 18, and 24 h after graded supine cycle exercise to volitional exhaustion. On another day, this 24-h protocol was repeated with no exercise (control). Beat-to-beat R-R intervals were measured during external application of graded pressures to the carotid sinuses from 40 to -65 mmHg; changes of R-R intervals were plotted against carotid pressure (systolic pressure minus neck chamber pressure). The maximum slope of the response relationship increased (P less than 0.05) from preexercise to 12 h (3.7 +/- 0.4 to 7.1 +/- 0.7 ms/mmHg) and remained significantly elevated through 24 h. The range of the R-R response was also increased from 217 +/- 24 to 274 +/- 32 ms (P less than 0.05). No significant differences were observed during the control 24-h period. An acute bout of graded exercise designed to elicit exhaustion increases the sensitivity and range of the carotid-cardiac baroreflex response for 24 h and enhances its capacity to buffer against hypotension by increasing heart rate. These results may represent an underlying mechanism that contributes to blood pressure stability after intense exercise.

The effect of exercise mode and intensity of sub-maximal physical activities on salivary testosterone to cortisol ratio and α-amylase in young active males

PubMed Central

AZARBAYJANI, MOHAMMAD ALI; FATOLAHI, HOSEYN; RASAEE, MOHAMMAD JAVAD; PEERI, MAGHSOD; BABAEI, ROHOLAH

2011-01-01

We examined the effect of exercise intensity and mode on the acute responses of free testosterone to cortisol ratio and salivary α-amylase. We also evaluated the relationship between cortisol and salivary α-amylase. Ten healthy young active males participated voluntarily in this study in six single sessions. They exercised on a cycle ergo meter, treadmill, and elliptical instrument at intensities of 70% and 85% maximum heart rate for 25 minutes. Saliva samples were collected 5 minutes before and 5 minutes after each exercise session. No significant changes were observed for cortisol. Free testosterone to cortisol ratio increased during each exercise session (F5, 45=3.15, P=0.02). However, these changes are only significant after exercise on the treadmill at 70% maximum heart rate (t=2.94, P=0.02) and 85% maximum heart rate (t=0.53, P=0.03). Salivary α-amylase significantly varied among exercise sessions (F5, 45=3.97, P=0.005), and a significant decline was observed after exercise on the elliptical instrument (t=2.38, P=0.04) and treadmill (t=3.55, P=0.006) at 85% maximum heart rate. We found that the free testosterone to cortisol ratio is dependent on the exercise mode, while the salivary α-amylase response is dependent on the intensity of exercise. The increase of free testosterone to cortisol ratio in this study may indicate lower physiological stress in response to performing these exercises. Applying muscular strength with moderate intensity weight-bearing exercises possibly activates the anabolic pathways. Although the cortisol and salivary α-amylase responses were opposite in the majority of the exercise sessions, no significant inverse relationship was observed. PMID:27182369

The effect of exercise mode and intensity of sub-maximal physical activities on salivary testosterone to cortisol ratio and α-amylase in young active males.

PubMed

Azarbayjani, Mohammad Ali; Fatolahi, Hoseyn; Rasaee, Mohammad Javad; Peeri, Maghsod; Babaei, Roholah

We examined the effect of exercise intensity and mode on the acute responses of free testosterone to cortisol ratio and salivary α-amylase. We also evaluated the relationship between cortisol and salivary α-amylase. Ten healthy young active males participated voluntarily in this study in six single sessions. They exercised on a cycle ergo meter, treadmill, and elliptical instrument at intensities of 70% and 85% maximum heart rate for 25 minutes. Saliva samples were collected 5 minutes before and 5 minutes after each exercise session. No significant changes were observed for cortisol. Free testosterone to cortisol ratio increased during each exercise session (F 5, 45 =3.15, P=0.02) . However, these changes are only significant after exercise on the treadmill at 70% maximum heart rate ( t=2.94, P=0.02 ) and 85% maximum heart rate ( t=0.53, P=0.03 ). Salivary α-amylase significantly varied among exercise sessions (F 5, 45 =3.97, P=0.005), and a significant decline was observed after exercise on the elliptical instrument (t=2.38, P=0.04) and treadmill ( t=3.55, P=0.006 ) at 85% maximum heart rate. We found that the free testosterone to cortisol ratio is dependent on the exercise mode, while the salivary α-amylase response is dependent on the intensity of exercise. The increase of free testosterone to cortisol ratio in this study may indicate lower physiological stress in response to performing these exercises. Applying muscular strength with moderate intensity weight-bearing exercises possibly activates the anabolic pathways. Although the cortisol and salivary α-amylase responses were opposite in the majority of the exercise sessions, no significant inverse relationship was observed.

Effects of Detraining on Anthropometry, Aerobic Capacity and Functional Ability in Adults with Down Syndrome

ERIC Educational Resources Information Center

Boer, P. H.

2018-01-01

Background: Structured exercise has shown to improve parameters of functional fitness in adults with Down syndrome (DS). However, few, if any, continue to exercise after exercise intervention studies. Consequently, the purpose of this study was to determine the effects of detraining on anthropometry, aerobic capacity and functional ability of…

Association Between Exercise Capacity and Late Onset of Dementia, Alzheimer Disease, and Cognitive Impairment.

PubMed

Müller, Jan; Chan, Khin; Myers, Jonathan N

2017-02-01

To address the association between exercise capacity and the onset of dementia, Alzheimer disease, and cognitive impairment. For 6104 consecutive veteran patients (mean ± SD age: 59.2±11.4 years) referred for treadmill exercise testing, the combined end point of dementia, Alzheimer disease, and cognitive impairment was abstracted from the Veterans Affairs computerized patient record system. After mean ± SD follow-up of 10.3±5.5 years, 353 patients (5.8%) developed the composite end point at a mean ± SD age of 76.7±10.3 years. After correction for confounders in multivariate Cox proportional hazards regression, higher age at exercise testing (hazard ratio [HR]=1.08; 95% CI, 1.07-1.09; P<.001), current smoking (HR=1.44; 95% CI, 1.08-1.93; P=.01), and exercise capacity (HR=0.92; 95% CI, 0.89-0.96; P<.001) emerged as predictors of cognitive impairment. Each 1-metabolic equivalent increase in exercise capacity conferred a nearly 8% reduction in the incidence of cognitive impairment. Meeting the recommendations for daily activity was not associated with a delay in onset of cognitive impairment (HR=1.07; 95% CI, 0.86-1.32; P=.55). Exercise capacity is strongly associated with cognitive function; the inverse association between fitness and cognitive impairment provides an additional impetus for health care providers to promote physical activity. Copyright © 2016 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.

Predictors and Association With Clinical Outcomes of the Changes in Exercise Capacity After Transcatheter Aortic Valve Replacement.

PubMed

Abdul-Jawad Altisent, Omar; Puri, Rishi; Regueiro, Ander; Chamandi, Chekrallah; Rodriguez-Gabella, Tania; Del Trigo, Maria; Campelo-Parada, Francisco; Couture, Thomas; Marsal, Josep Ramon; Côté, Mélanie; Paradis, Jean-Michel; DeLarochellière, Robert; Doyle, Daniel; Mohammadi, Siamak; Dumont, Eric; Rodés-Cabau, Josep

2017-08-15

At present, there are no objective data specifically examining the clinical impact of variations in exercise capacity post-transcatheter aortic valve replacement (TAVR). We describe the changes in exercise capacity between baseline and 6 months post-TAVR, and ascertain factors associated with and clinical implications of a lack of improvement in exercise capacity post-TAVR. A total of 305 patients (mean age, 79±9 years; 44% men; Society of Thoracic Surgeons predicted risk mortality score, 6.7±4.2%) undergoing TAVR completed both baseline and follow-up exercise capacity assessments at 6 months post-TAVR. Exercise capacity was evaluated by the 6-minute walk test (6MWT). Clinical outcomes were compared between patients displaying greater than (n=152; improving group) versus less than (n=153; nonimproving group) the median percentage change in distance walked between baseline and 6-month follow-up examinations. The primary outcome measure was clinical event rates, measured from the 6-month post-TAVR period onward. Further dichotomization according to baseline 6MWT distance (less than versus more than median walking distance, or slow walker versus fast walker) was also assessed. The mean overall distances walked pre- and post-TAVR (6 months post-TAVR) were 204±119 and 263±116 m, respectively (Δ6MWT=60±106 m), with 219 (72%) patients demonstrating an increase in their walking distance (median percentage increase of the entire population was 20% [interquartile range, 0%-80%]). Factors independently correlated with reduced exercise capacity improvement included a range of baseline clinical characteristics (older age, female sex, chronic obstructive pulmonary disease; P <0.05 for all), periprocedural major or life-threatening bleeding ( P =0.009) and new-onset anemia at 6 months post-TAVR ( P =0.009). Failure to improve the 6MWT distance by at least 20% was independently associated with all-cause mortality ( P =0.002) and cardiovascular death or rehospitalization for cardiovascular causes ( P =0.001). Baseline slow walkers who were able to improve the 6MWT distance presented with significantly better outcomes than nonimprovers ( P =0.01 for all-cause mortality; P =0.001 for cardiovascular end point). Approximately one-third of patients undergoing TAVR did not improve their exercise capacity postprocedure. The lack of functional improvement post-TAVR was predicted by a mix of baseline and periprocedural factors translating into poorer clinical outcomes. These results suggest that systematically implementing exercise capacity assessment pre- and post-TAVR may help to improve patient risk stratification. © 2017 American Heart Association, Inc.

Rapamycin increases grip strength and attenuates age-related decline in maximal running distance in old low capacity runner rats

PubMed Central

Xue, Qian-Li; Yang, Huanle; Li, Hui-Fen; Abadir, Peter M.; Burks, Tyesha N.; Koch, Lauren G.; Britton, Steven L.; Carlson, Joshua; Chen, Laura; Walston, Jeremy D.; Leng, Sean X.

2016-01-01

Rapamycin is known to extend lifespan. We conducted a randomized placebo-controlled study of enteric rapamycin-treatment to evaluate its effect on physical function in old low capacity runner (LCR) rats, a rat model selected from diverse genetic background for low intrinsic aerobic exercise capacity without genomic manipulation and characterized by increased complex disease risks and aging phenotypes. The study was performed in 12 male and 16 female LCR rats aged 16-22 months at baseline. The treatment group was fed with rapamycin-containing diet pellets at approximately 2.24mg/kg body weight per day and the placebo group with the same diet without rapamycin for six months. Observation was extended for additional 2 months. Physical function measurements include grip strength measured as maximum tensile force using a rat grip strength meter and maximum running distance (MRD) using rat physical treadmill test. The results showed that rapamycin improved grip strength by 13% (p=.036) and 60% (p<.001) from its baseline in female and male rats, respectively. Rapamycin attenuated MRD decline by 66% (p<.001) and 46% (p=.319) in females and males, respectively. These findings provide initial evidence for beneficial effect of rapamycin on physical functioning in an aging rat model of high disease risks with significant implication in humans. PMID:26997106

Does nebulized fentanyl relieve dyspnea during exercise in healthy man?

PubMed Central

Kotrach, Houssam G.; Bourbeau, Jean

2015-01-01

Few therapies exist for the relief of dyspnea in restrictive lung disorders. Accumulating evidence suggests that nebulized opioids selective for the mu-receptor subtype may relieve dyspnea by modulating intrapulmonary opioid receptor activity. Our respective primary and secondary objectives were to test the hypothesis that nebulized fentanyl (a mu-opioid receptor agonist) relieves dyspnea during exercise in the presence of abnormal restrictive ventilatory constraints and to identify the physiological mechanisms of this improvement. In a randomized, double-blind, placebo-controlled crossover study, we examined the effect of 250 μg nebulized fentanyl, chest wall strapping (CWS), and their interaction on detailed physiological and perceptual responses to constant work rate cycle exercise (85% of maximum incremental work rate) in 14 healthy, fit young men. By design, CWS decreased vital capacity by ∼20% and mimicked the negative consequences of a mild restrictive lung disorder on exercise endurance time and on dyspnea, breathing pattern, dynamic operating lung volumes, and diaphragmatic electromyographic and respiratory muscle function during exercise. Compared with placebo under both unrestricted control and CWS conditions, nebulized fentanyl had no effect on exercise endurance time, integrated physiological response to exercise, sensory intensity, unpleasantness ratings of exertional dyspnea. Our results do not support a role for intrapulmonary opioids in the neuromodulation of exertional dyspnea in health nor do they provide a physiological rationale for the use of nebulized fentanyl in the management of dyspnea due to mild restrictive lung disorders, specifically those arising from abnormalities of the chest wall and not affiliated with airway inflammation. PMID:26031762

Exercise starts and ends in the brain.

PubMed

Kayser, Bengt

2003-10-01

Classically the limit to endurance of exercise is explained in terms of metabolic capacity. Cardio-respiratory capacity and muscle fatigue are thought to set the limit and the majority of studies on factors limiting endurance exercise discuss issues such as maximal oxygen uptake (VO2max), aerobic enzyme capacity, cardiac output, glycogen stores, etc. However, this paradigm does not explain the limitation to endurance exercise with large muscle groups at altitude, when at exhaustion exercise is ended without limb locomotor muscle fatigue and with sub-maximal cardiac output. A simple fact provides a basis for an explanation. Voluntary exercise starts and ends in the brain. It starts with spatial and temporal recruitment of motor units and ends with their de-recruitment. A conscious decision precedes a voluntary effort. The end of effort is again volitional and a forced conscious decision to stop precedes it, but it is unknown what forces the off-switch of recruitment at exhaustion although sensation of exertion certainly plays a role. An alternative model explaining the limitation of exercise endurance thus proposes that the central nervous system integrates input from various sources all related to the exercise and limits the intensity and duration of recruitment of limb skeletal muscle to prevent jeopardizing the integrity of the organism. This model acknowledges the cardio-respiratory and muscle metabolic capacities as prime actors on the performance scene, while crediting the central nervous system for its pivotal role as the ultimate site where exercise starts and ends.

Body mass index, exercise capacity, and mortality risk in male veterans with hypertension.

PubMed

Faselis, Charles; Doumas, Michael; Panagiotakos, Demosthenes; Kheirbek, Raya; Korshak, Lauren; Manolis, Athanasios; Pittaras, Andreas; Tsioufis, Costas; Papademetriou, Vasilios; Fletcher, Ross; Kokkinos, Peter

2012-04-01

Overweight and obesity are associated with increased risk of chronic diseases and mortality. Exercise capacity is inversely associated with mortality risk. However, little is known on the interaction between fitness, fatness, and mortality risk in hypertensive individuals. Thus, we assessed the interaction between exercise capacity, fatness, and all-cause mortality in hypertensive males. A graded exercise test was performed in 4,183 hypertensive veterans (mean age ± s.d.; 63.3 ± 10.5 years) at the Veterans Affairs Medical Center, Washington, DC. We defined three body weight categories based on body mass index (BMI): normal weight (BMI <25); overweight (BMI 25-29.9); and obese (BMI ≥30); and three fitness categories based on peak metabolic equivalents (METs) achieved: low-fit (≤5 METs); moderate-fit (5.1-7.5 MET); and high-fit (>7.5 METs). During a median follow-up period of 7.2 years, there were 1,000 deaths. The association between exercise capacity and mortality risk was strong, inverse, and graded. For each 1-MET increase in exercise capacity the adjusted risk was 20% for normal weight, 12% for overweight, and 25% for obese (P < 0.001). When compared to normal weight but unfit individuals, mortality risks were 60% lower in the overweight/high-fit and 78% lower in the obese/high-fit individuals (P < 0.001). Increased exercise capacity is associated with lower mortality risk in hypertensive males regardless of BMI. The risk for overweight and obese but fit individuals was significantly lower when compared to normal weight but unfit. These findings suggest that in older hypertensive men, it may be healthier to be fit regardless of standard BMI category than unfit and normal weight.

Exercise training modalities in chronic heart failure: does high intensity aerobic interval training make the difference?

PubMed

Giallauria, Francesco; Smart, Neil Andrew; Cittadini, Antonio; Vigorito, Carlo

2016-10-14

Exercise training (ET) is strongly recommended in patients with chronic heart failure (CHF). Moderate-intensity aerobic continuous ET is the best established training modality in CHF patients. In the last decade, however, high-intensity interval exercise training (HIIT) has aroused considerable interest in cardiac rehabilitation community. Basically, HIIT consists of repeated bouts of high-intensity exercise alternated with recovery periods. In CHF patients, HIIT exerts larger improvements in exercise capacity compared to moderate-continuous ET. These results are intriguing, mostly considering that better functional capacity translates into an improvement of symptoms and quality of life. Notably, HIIT did not reveal major safety issues; although CHF patients should be clinically stable, have had recent exposure to at least regular moderate-intensity exercise, and appropriate supervision and monitoring during and after the exercise session are mandatory. The impact of HIIT on cardiac dimensions and function and on endothelial function remains uncertain. HIIT should not replace other training modalities in heart failure but should rather complement them. Combining and tailoring different ET modalities according to each patient's baseline clinical characteristics (i.e. exercise capacity, personal needs, preferences and goals) seem the most astute approach to exercise prescription.

Combined short-arm centrifuge and aerobic exercise training improves cardiovascular function and physical working capacity in humans.

PubMed

Yang, Chang-Bin; Zhang, Shu; Zhang, Yu; Wang, Bing; Yao, Yong-Jie; Wang, Yong-Chun; Wu, Yan-Hong; Liang, Wen-Bin; Sun, Xi-Qing

2010-12-01

Musculoskeletal and cardiovascular deconditioning occurring in long-term spaceflight gives rise to the needs to develop new strategies to counteract these adverse effects. Short-arm centrifuge combined with ergometer has been proposed as a strategy to counteract adverse effects of microgravity. This study sought to investigate whether the combination of short-arm centrifuge and aerobic exercise training have advantages over short-arm centrifuge or aerobic exercise training alone. One week training was conducted by 24 healthy men. They were randomly divided into 3 groups: (1) short-arm centrifuge training, (2) aerobic exercise training, 40 W, and (3) combined short-arm centrifuge and aerobic exercise training. Before and after training, the cardiac pump function represented by stroke volume, cardiac output, left ventricular ejection time, and total peripheral resistance was evaluated. Variability of heart rate and systolic blood pressure were determined by spectral analysis. Physical working capacity was surveyed by near maximal physical working capacity test. The 1-week combined short-arm centrifuge and aerobic exercise training remarkably ameliorated the cardiac pump function and enhanced vasomotor sympathetic nerve modulation and improved physical working capacity by 10.9% (P<.05, n=8). In contrast, neither the short-arm centrifuge nor the aerobic exercise group showed improvements in these functions. These results demonstrate that combined short-arm centrifuge and aerobic exercise training has advantages over short-arm centrifuge or aerobic exercise training alone in influencing several physiologically important cardiovascular functions in humans. The combination of short-arm centrifuge and aerobic exercise offers a promising countermeasure to microgravity.

Exercise training improves characteristics of exercise oscillatory ventilation in chronic heart failure.

PubMed

Panagopoulou, Niki; Karatzanos, Eleftherios; Dimopoulos, Stavros; Tasoulis, Athanasios; Tachliabouris, Ioannis; Vakrou, Styliani; Sideris, Antonios; Gratziou, Christina; Nanas, Serafim

2017-05-01

Background Exercise oscillatory ventilation in chronic heart failure has been suggested as a factor related to adverse cardiac events, aggravated prognosis and higher mortality. Exercise training is well known to affect exercise capacity and mechanisms of pathophysiology beneficially in chronic heart failure. Little is known, however, about the exercise training effects on characteristics of exercise oscillatory ventilation in chronic heart failure patients. Design and methods Twenty (out of 38) stable chronic heart failure patients exhibited exercise oscillatory ventilation (age 54 ± 11 years, peak oxygen uptake 15.0 ± 5.0 ml/kg per minute). Patients attended 36 sessions of high intensity interval exercise. All patients underwent cardiopulmonary exercise testing before and after the programme. Assessment of exercise oscillatory ventilation was based on the amplitude of cyclic fluctuations in breathing during rest and exercise. All values are mean ± SD. Results Exercise training reduced ( P < 0.05) the percentage of exercise oscillatory ventilation duration (79.0 ± 13.0 to 50.0 ± 25.0%), while average amplitude (5.2 ± 2.0 to 4.9 ± 1.6 L/minute) and length (44.0 ± 10.9 to 41.0 ± 6.7 seconds) did not change ( P > 0.05). Exercise oscillatory ventilation patients also increased exercise capacity ( P < 0.05). Conclusions A rehabilitation programme based on high intensity interval training improved exercise oscillatory ventilation observed in chronic heart failure patients, as well as cardiopulmonary efficiency and functional capacity.

Supplementation with a Polyphenol-Rich Extract, PerfLoad®, Improves Physical Performance during High-Intensity Exercise: A Randomized, Double Blind, Crossover Trial

PubMed Central

Cases, Julien; Romain, Cindy; Marín-Pagán, Cristian; Chung, Linda H.; Rubio-Pérez, José Miguel; Laurent, Caroline; Gaillet, Sylvie; Prost-Camus, Emmanuelle; Prost, Michel; Alcaraz, Pedro E.

2017-01-01

Workout capacity is energy-production driven. To produce peak metabolic power outputs, the organism predominantly relies more on anaerobic metabolism, but this undoubtedly has a negative and limiting impact on muscle function and performance. The aim of the study was to evaluate if an innovative polyphenol-based food supplement, PerfLoad®, was able to improve metabolic homeostasis and physical performance during high-intensity exercises under anaerobic conditions. The effect of a supplementation has been investigated on fifteen recreationally-active male athletes during a randomized, double-blind and crossover clinical investigation. The Wingate test, an inducer of an unbalanced metabolism associated to oxidative stress, was used to assess maximum anaerobic power during a high-intensity exercise on a cycle ergometer. Supplementation with PerfLoad® correlated with a significant increase in total power output (5%), maximal peak power output (3.7%), and average power developed (5%), without inducing more fatigue or greater heart rate. Instead, oxidative homeostasis was stabilized in supplemented subjects. Such results demonstrated that PerfLoad® is a natural and efficient solution capable of, similarly to training benefits, helping athletes to improve their physical performance, while balancing their metabolism and reducing exercise-induced oxidative stress. PMID:28441760

Work, exercise, and space flight. 2: Modification of adaptation by exercise (exercise prescription)

NASA Technical Reports Server (NTRS)

Thornton, William

1989-01-01

The fundamentals of exercise theory on earth must be rigorously understood and applied to prevent adaptation to long periods of weightlessness. Locomotor activity, not weight, determines the capacity or condition of the largest muscles and bones in the body and usually also determines cardio-respiratory capacity. Absence of this activity results in rapid atrophy of muscle, bone, and cardio-respiratory capacity. Upper body muscle and bone are less affected depending upon the individual's usual, or 1-g, activities. Methodology is available to prevent these changes but space operations demand that it be done in the most efficient fashion, i.e., shortest time. At this point in time we can reasonably select the type of exercise and methods of obtaining it, but additional work in 1-g will be required to optimize the time.

Effects of rehydration and food consumption on salivary flow, pH and buffering capacity in young adult volunteers during ergometer exercise

PubMed Central

2013-01-01

Background The aim of this study was to investigate the influences of rehydration and food consumption on salivary flow, pH, and buffering capacity during bicycle ergometer exercise in participants. Methods Ten healthy volunteers exercised on a bicycle ergometer at 80% of their maximal heart rate. These sessions lasted for two periods of 20 min separated by 5-min rest intervals. Volunteers were subjected to one of the following conditions: (1) no water (mineral water) or food consumption, (2) only water for rehydration, (3) water and food consumption, (4) a sports drink only for rehydration, and (5) rehydration with a sports drink and food. Statistical significance was assessed using one-way analysis of variance and Dunnett’s test (p < 0.05). Results The salivary pH decreased significantly during and after exercise in conditions 4 and 5. The salivary buffering capacity decreased significantly during exercise and/or after the exercise in conditions 1, 3, 4, and 5. Conclusions The results showed that salivary pH and buffering capacity decreased greatly depending on the combination of a sports drink and food. PMID:24160307

Attenuated post-exercise heart rate recovery in patients with systemic lupus erythematosus: the role of disease severity and beta-blocker treatment.

PubMed

Bienias, P; Ciurzyński, M; Chrzanowska, A; Dudzik-Niewiadomska, I; Irzyk, K; Oleszek, K; Kalińska-Bienias, A; Kisiel, B; Tłustochowicz, W; Pruszczyk, P

2018-02-01

Objective Sinus tachycardia is frequently reported in systemic lupus erythematosus (SLE), while there are limited data on post-exercise ability to slow heart rate (i.e. heart rate recovery, HRR) in this group of patients. Methods We studied consecutive 70 patients with SLE and 30 healthy controls. All examined individuals underwent detailed clinical examination, echocardiography, Holter monitoring with heart rate variability and treadmill stress test using Bruce's protocol. HRR values were calculated as the difference between maximum HR during exercise and HR at the first (HRR1) and third (HRR3) minute of rest. Individuals with coronary artery disease, diabetes mellitus and suspected pulmonary hypertension were excluded from further analysis ( n = 15). Results Fifty-five SLE patients were eligible for this study: aged 41.5 ± 12.4 years, 87.3% women, SLICC/ACR-DI score 3.58 ± 1.85. In the SLE group 36.4% patients received beta-blockers, usually for previously detected sinus tachycardia and/or arterial hypertension. Mean HRR1 (36.9 ± 12.6 vs 49.5 ± 18.6, p = 0.0004) and HRR3 (55.5 ± 14.3 vs 69.2 ± 16.4, p = 0.0001) were significantly lower in SLE than in healthy individuals. Significantly negative correlations between SLICC/ACR-DI score and HRR1 ( r = -0.299, p = 0.01), HRR3 ( r = -0.361, p = 0.001) and exercise capacity ( r = -0.422, p < 0.0001) were revealed. Additionally, beta-blocker treatment was also revealed to alter significantly HRR1, HRR3 and exercise capacity in SLE. Conclusion Patients with SLE are characterized by attenuated HRR after exercise. In our study impaired HRR was associated with disease severity and beta-blocker treatment and probably with disease duration. The use of HRR assessment in SLE can be used as an additional marker of cardiac autonomic nervous system dysfunction.

Poor glycaemic control is associated with reduced exercise performance and oxygen economy during cardio-pulmonary exercise testing in people with type 1 diabetes.

PubMed

Moser, Othmar; Eckstein, Max L; McCarthy, Olivia; Deere, Rachel; Bain, Stephen C; Haahr, Hanne L; Zijlstra, Eric; Bracken, Richard M

2017-01-01

To explore the impact of glycaemic control (HbA 1c ) on functional capacity during cardio-pulmonary exercise testing in people with type 1 diabetes. Sixty-four individuals with type 1 diabetes (age: 34 ± 8 years; 13 females, HbA 1c : 7.8 ± 1% (62 ± 13 mmol/mol), duration of diabetes: 17 ± 9 years) performed a cardio-pulmonary cycle ergometer exercise test until volitional exhaustion. Stepwise linear regression was used to explore relationships between HbA 1c and cardio-respiratory data with p ≤ 0.05. Furthermore, participants were divided into quartiles based on HbA 1c levels and cardio-respiratory data were analysed by one-way ANOVA. Multiple regression analysis was performed to explore the relationships between changes in time to exhaustion and cardio-respiratory data. Data were adjusted for confounder. HbA 1c was related to time to exhaustion and oxygen consumption at the power output elicited at the sub-maximal threshold of the heart rate turn point (r = 0.47, R 2  = 0.22, p = 0.03). Significant differences were found at time to exhaustion between Q I vs. Q IV and at oxygen consumption at the power output elicited at the heart rate turn point between Q I vs. Q II and Q I vs. Q IV (p < 0.05). Changes in oxygen uptake, power output and in oxygen consumption at the power output elicited at the heart rate turn point and at maximum power output explained 55% of the variance in time to exhaustion ( r  = 0.74, R 2  = 0.55, p < 0.01). Poor glycaemic control is related to less economical use of oxygen at sub-maximal work rates and an earlier time to exhaustion during cardio-pulmonary exercise testing. However, exercise training could have the same potential to counteract the influence of poor glycaemic control on functional capacity. Trial registration NCT01704417. Date of registration: October 11, 2012.

Physiological and perceptual responses to incremental exercise testing in healthy men: effect of exercise test modality.

PubMed

Muscat, Kristina M; Kotrach, Houssam G; Wilkinson-Maitland, Courtney A; Schaeffer, Michele R; Mendonca, Cassandra T; Jensen, Dennis

2015-11-01

In a randomized cross-over study of 15 healthy men aged 20-30 years, we compared physiological and perceptual responses during treadmill and cycle exercise test protocols matched for increments in work rate - the source of increased locomotor muscle metabolic and contractile demands. The rates of O2 consumption and CO2 production were higher at the peak of treadmill versus cycle testing (p ≤ 0.05). Nevertheless, work rate, minute ventilation, tidal volume (VT), breathing frequency (fR), inspiratory capacity (IC), inspiratory reserve volume (IRV), tidal esophageal (Pes,tidal) and transdiaphragmatic pressure swings (Pdi,tidal), peak expiratory gastric pressures (Pga,peak), the root mean square of the diaphragm electromyogram (EMGdi,rms) expressed as a percentage of maximum EMGdi,rms (EMGdi,rms%max), and dyspnea ratings were similar at the peak of treadmill versus cycle testing (p > 0.05). Ratings of leg discomfort were higher at the peak of cycle versus treadmill exercise (p ≤ 0.05), even though peak O2 consumption was lower during cycling. Oxygen consumption, CO2 production, minute ventilation, fR, Pes,tidal, Pdi,tidal and Pga,peak were higher (p ≤ 0.05), while VT, IC, IRV, EMGdi,rms%max, and ratings of dyspnea and leg discomfort were similar (p > 0.05) at all or most submaximal work rates during treadmill versus cycle exercise. Our findings highlight important differences (and similarities) in physiological and perceptual responses at maximal and submaximal work rates during incremental treadmill and cycle exercise testing protocols. The lack of effect of exercise test modality on peak work rate advocates for the use of this readily available parameter to optimize training intensity determination, regardless of exercise training mode.

Cureton's Basic Principles of Physical Fitness Work (Rules for Conducting Exercise).

ERIC Educational Resources Information Center

President's Council on Physical Fitness and Sports, Washington, DC.

This document is an annotated list of 20 rules for conducting exercise. Among the rules described are the warm-up rule, the rule for regulation of exercise dosage, recuperation rule, posture rule, glandular fitness rule, maximum respiration rule, and maximum circulation rule. The time of workout and procedures for taking cool baths are…

Influence of acute exercise of varying intensity and duration on postprandial oxidative stress.

PubMed

Canale, Robert E; Farney, Tyler M; McCarthy, Cameron G; Bloomer, Richard J

2014-09-01

Aerobic exercise can reduce postprandial lipemia, and possibly oxidative stress, when performed prior to a lipid-rich meal. To compare the impact of acute exercise on postprandial oxidative stress. We compared aerobic and anaerobic exercise bouts of different intensities and durations on postprandial blood triglycerides (TAG), oxidative stress biomarkers (malondialdehyde, hydrogen peroxide, advanced oxidation protein products), and antioxidant status (trolox equivalent antioxidant capacity, superoxide dismutase, catalase, glutathione peroxidase). Twelve trained men (21-35 years) underwent four conditions: (1) No exercise rest; (2) 60-min aerobic exercise at 70% heart rate reserve; (3) five 60-s sprints at 100% max capacity; and (4) ten 15-s sprints at 200% max capacity. All exercise bouts were performed on a cycle ergometer. A high-fat meal was consumed 1 h after exercise cessation. Blood samples were collected pre-meal and 2 and 4 h post-meal and analyzed for TAG, oxidative stress biomarkers, and antioxidant status. No significant interaction or condition effects were noted for any variable (p > 0.05), with acute exercise having little to no effect on the magnitude of postprandial oxidative stress. In a sample of healthy, well-trained men, neither aerobic nor anaerobic exercise attenuates postprandial oxidative stress in response to a high-fat meal.

Feedback-controlled robotics-assisted treadmill exercise to assess and influence aerobic capacity early after stroke: a proof-of-concept study.

PubMed

Stoller, Oliver; Schindelholz, Matthias; Bichsel, Lukas; Schuster, Corina; de Bie, Rob A; de Bruin, Eling D; Hunt, Kenneth J

2014-07-01

The majority of post-stroke individuals suffer from low exercise capacity as a secondary reaction to immobility. The aim of this study was to prove the concept of feedback-controlled robotics-assisted treadmill exercise (RATE) to assess aerobic capacity and guide cardiovascular exercise in severely impaired individuals early after stroke. Subjects underwent constant load and incremental exercise testing using a human-in-the-loop feedback system within a robotics-assisted exoskeleton (Lokomat, Hocoma AG, CH). Inclusion criteria were: stroke onset ≤8 weeks, stable medical condition, non-ambulatory status, moderate motor control of the lower limbs and appropriate cognitive function. Outcome measures included oxygen uptake kinetics, peak oxygen uptake (VO2peak), gas exchange threshold (GET), peak heart rate (HRpeak), peak work rate (Ppeak) and accuracy of reaching target work rate (P-RMSE). Three subjects (18-42 d post-stroke) were included. Oxygen uptake kinetics during constant load ranged from 42.0 to 60.2 s. Incremental exercise testing showed: VO2peak range 19.7-28.8 ml/min/kg, GET range 11.6-12.7 ml/min/kg, and HRpeak range 115-161 bpm. Ppeak range was 55.2-110.9 W and P-RMSE range was 3.8-7.5 W. The concept of feedback-controlled RATE for assessment of aerobic capacity and guidance of cardiovascular exercise is feasible. Further research is warranted to validate the method on a larger scale. Aerobic capacity is seriously reduced in post-stroke individuals as a secondary reaction to immobility. Robotics-assisted walking devices may have substantial clinical relevance regarding assessment and improvement of aerobic capacity early after stroke. Feedback-controlled robotics-assisted treadmill exercise represents a new concept for cardiovascular assessment and intervention protocols for severely impaired individuals.

Exercise Capacity and Functional Performance in Heart Failure Patients Supported by a Left Ventricular Assist Device at Discharge From Inpatient Rehabilitation.

PubMed

Schmidt, Thomas; Bjarnason-Wehrens, Birna; Bartsch, Petra; Deniz, Ezin; Schmitto, Jan; Schulte-Eistrup, Sebastian; Willemsen, Detlev; Reiss, Nils

2018-01-01

Adequate physical and functional performance is an important prerequisite for renewed participation and integration in self-determined private and (where appropriate) professional lives following left ventricular assist device (LVAD) implantation. During cardiac rehabilitation (CR), individually adapted exercise programs aim to increase exercise capacity and functional performance. A retrospective analysis of cardiopulmonary exercise capacity and functional performance in LVAD patients at discharge from a cardiac rehabilitation program was conducted. The results from 68 LVAD patients (59 males, 9 females; 55.9 ± 11.7 years; 47 HVAD, 2 MVAD, 15 HeartMate II, 4 HeartMate 3, and 4 different implanting centers) were included in the analysis. Exercise capacity was assessed using a cardiopulmonary exercise test on a bicycle ergometer (ramp protocol; 10 W/min). The 6-min walk test was used to determine functional performance. At discharge from CR (53 ± 17 days after implantation), the mean peak work load achieved was 62.2 ± 19.3 W (38% of predicted values) or 0.79 ± 0.25 W/kg body weight. The mean cardiopulmonary exercise capacity (relative peak oxygen uptake) was 10.6 ± 5.3 mL/kg/min (37% of predicted values). The 6-min walk distance improved significantly during CR (325 ± 106 to 405 ± 77 m; P < 0.01). No adverse events were documented during CR. The results show that, even following LVAD implantation, cardiopulmonary exercise capacity remains considerably restricted. In contrast, functional performance, measured by the 6-min walk distance, reaches an acceptable level. Light everyday tasks seem to be realistically surmountable for patients, making discharge from inpatient rehabilitation possible. Long-term monitoring is required in order to evaluate the situation and how it develops further. © 2017 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Long-term follow-up of patients receiving lung-volume-reduction surgery versus medical therapy for severe emphysema by the National Emphysema Treatment Trial Research Group.

PubMed

Naunheim, Keith S; Wood, Douglas E; Mohsenifar, Zab; Sternberg, Alice L; Criner, Gerard J; DeCamp, Malcolm M; Deschamps, Claude C; Martinez, Fernando J; Sciurba, Frank C; Tonascia, James; Fishman, Alfred P

2006-08-01

The National Emphysema Treatment Trial defined subgroups of patients with severe emphysema in whom lung-volume-reduction surgery (LVRS) improved survival and function at 2 years. Two additional years of follow-up provide valuable information regarding durability. A total of 1218 patients with severe emphysema were randomized to receive LVRS or medical treatment. We present updated analyses (4.3 versus 2.4 years median follow-up), including 40% more patients with functional measures 2 years after randomization. The intention-to-treat analysis of 1218 randomized patients demonstrates an overall survival advantage for LVRS, with a 5-year risk ratio (RR) for death of 0.86 (p = 0.02). Improvement was more likely in the LVRS than in the medical group for maximal exercise through 3 years and for health-related quality of life (St. George's Respiratory Questionnaire [SGRQ]) through 4 years. Updated comparisons of survival and functional improvement were consistent with initial results for four clinical subgroups of non-high-risk patients defined by upper-lobe predominance and exercise capacity. After LVRS, the upper-lobe patients with low exercise capacity demonstrated improved survival (5-year RR, 0.67; p = 0.003), exercise throughout 3 years (p < 0.001), and symptoms (SGRQ) through 5 years (p < 0.001 years 1 to 3, p = 0.01 year 5). Upper-lobe-predominant and high-exercise-capacity LVRS patients obtained no survival advantage but were likely to improve exercise capacity (p < 0.01 years 1 to 3) and SGRQ (p < 0.01 years 1 to 4). Effects of LVRS are durable, and it can be recommended for upper-lobe-predominant emphysema patients with low exercise capacity and should be considered for palliation in patients with upper-lobe emphysema and high exercise capacity.

Resistance training and mitochondrial metabolism

USDA-ARS?s Scientific Manuscript database

Objective: To determine if resistance exercise training improves skeletal muscle substrate oxidative capacity in older adults. Background: A decline in skeletal muscle oxidative capacity occurs with aging. Aerobic exercise increases skeletal muscle’s ability to oxidize multiple substrates. Th...

Effect of metformin on exercise capacity in metabolic syndrome.

PubMed

Paul, Abi Albon; Dkhar, Steven Aibor; Kamalanathan, Sadishkumar; Thabah, Molly Mary; George, Melvin; Chandrasekaran, Indumathi; Gunaseelan, Vikneswaran; Selvarajan, Sandhiya

2017-11-01

Metabolic syndrome is a constellation of risk factors with increased predilection towards occurrence of cardiovascular diseases. Currently physical exercise and management with metformin are the prevailing treatment modalities for metabolic syndrome. Patients with metabolic syndrome have been found to have reduced exercise capacity over a period of time. Likewise metformin has been shown to decrease exercise capacity among healthy volunteers. Hence this study aims to evaluate the effect of metformin on the exercise capacity of patients with metabolic syndrome. Prospective study with 6 weeks follow up. Newly diagnosed patients with metabolic syndrome and to be started on Table Metformin 500mg twice a day were recruited for the study after obtaining written informed consent. Cardiopulmonary Exercise Testing (CPET) was done at baseline before the subjects were started on metformin and after 6 weeks of treatment using cardiopulmonary exercise testing apparatus (ZAN600). Fifteen treatment naïve patients with metabolic syndrome completed six weeks of therapy with metformin. In these patients oxygen uptake [VO2] showed statistically significant decrease from 1.10±0.44 at baseline to 0.9±0.39 (l/min) after six weeks of treatment with metformin [mean difference of -0.20 (-0.31 to -0.09); P=0.001]. Similarly oxygen uptake/kg body weight [VO2/Kg] showed a significant decrease from 14.10±4.73 to 11.44±3.81 (mlkg -1 min -1 ) at the end of six weeks of treatment [mean difference of -2.66 (-4.06 to -1.26); P=0.001]. Six weeks of treatment with metformin significantly decreases exercise capacity in newly diagnosed patients with metabolic syndrome. Copyright © 2017 Diabetes India. Published by Elsevier Ltd. All rights reserved.

Reduced exercise capacity in genetic haemochromatosis.

PubMed

Davidsen, Einar Skulstad; Liseth, Knut; Omvik, Per; Hervig, Tor; Gerdts, Eva

2007-06-01

Many patients with genetic haemochromatosis complain about fatigue and reduced physical capacity. Exercise capacity, however, has not been evaluated in larger series of haemochromatosis patients treated with repeated phlebotomy. We performed exercise echocardiography in 152 treated haemochromatosis patients (48+/-13 years, 26% women) and 50 healthy blood donors (49+/-13 years, 30% women), who served as controls. Echocardiography was performed at rest and during exercise in a semiupright position on a chair bicycle, starting from 20 W, increasing by 20 W/min. Transmitral early and atrial velocity and isovolumic relaxation time were measured at each step. Ventilatory gas exchange was measured by the breath-to-breath-technique. Compared with healthy controls, haemochromatosis patients were more obese and less trained. More of them smoked, and 17% had a history of cardiovascular or pulmonary disease. Adjusted for training, the left ventricular function and dimensions at rest did not differ between the groups. During exercise the haemochromatosis patients obtained a significantly lower peak oxygen (O2) uptake (28.1 vs. 34.4 ml/kg per min, P<0.001). In a multiple regression analysis haemochromatosis predicted lower peak O2 uptake independently of significant contributions of sex, age, and height, as well as of systolic blood pressure and log-transformed isovolumic relaxation time at peak exercise, whereas no independent association was found with weight or physical activity (multiple R=0.74, P<0.001). Adding genotype, s-ferritin, prevalence of smoking, or history of cardiopulmonary disease among the covariates in subsequent models did not change the results. Genetic haemochromatosis, even when treated with regular phlebotomy, is associated with lower exercise capacity independently of other covariates of exercise capacity.

Statins are related to impaired exercise capacity in males but not females.

PubMed

Bahls, Martin; Groß, Stefan; Ittermann, Till; Busch, Raila; Gläser, Sven; Ewert, Ralf; Völzke, Henry; Felix, Stephan B; Dörr, Marcus

2017-01-01

Exercise and statins reduce cardiovascular disease (CVD). Exercise capacity may be assessed using cardiopulmonary exercise testing (CPET). Whether statin medication is associated with CPET parameters is unclear. We investigated if statins are related with exercise capacity during CPET in the general population. Cross-sectional data of two independent cohorts of the Study of Health in Pomerania (SHIP) were merged (n = 3,500; 50% males). Oxygen consumption (VO2) at peak exercise (VO2peak) and anaerobic threshold (VO2@AT) was assessed during symptom-limited CPET. Two linear regression models related VO2peak with statin usage were calculated. Model 1 adjusted for age, sex, previous myocardial infarction, and physical inactivity and model 2 additionally for body mass index, smoking, hypertension, diabetes and estimated glomerular filtration rate. Propensity score matching was used for validation. Statin usage was associated with lower VO2peak (no statin: 2336; 95%-confidence interval [CI]: 2287-2,385 vs. statin 2090; 95%-CI: 2,031-2149 ml/min; P < .0001) and VO2@AT (no statin: 1,172; 95%-CI: 1,142-1,202 vs. statin: 1,111; 95%-CI: 1,075-1,147 ml/min; P = .0061) in males but not females (VO2peak: no statin: 1,467; 95%-CI: 1,417-1,517 vs. statin: 1,503; 95%-CI: 1,426-1,579 ml/min; P = 1.00 and VO2@AT: no statin: 854; 95%-CI: 824-885 vs. statin 864; 95%-CI: 817-911 ml/min; P = 1.00). Model 2 revealed similar results. Propensity scores analysis confirmed the results. In the general population present statin medication was related with impaired exercise capacity in males but not females. Sex specific effects of statins on cardiopulmonary exercise capacity deserve further research.

Fine mapping of a QTL on chromosome 13 for submaximal exercise capacity training response: the HERITAGE Family Study.

PubMed

Rice, Treva K; Sarzynski, Mark A; Sung, Yun Ju; Argyropoulos, George; Stütz, Adrian M; Teran-Garcia, Margarita; Rao, D C; Bouchard, Claude; Rankinen, Tuomo

2012-08-01

Although regular exercise improves submaximal aerobic capacity, there is large variability in its response to exercise training. While this variation is thought to be partly due to genetic differences, relatively little is known about the causal genes. Submaximal aerobic capacity traits in the current report include the responses of oxygen consumption (ΔVO(2)60), power output (ΔWORK60), and cardiac output (ΔQ60) at 60% of VO2max to a standardized 20-week endurance exercise training program. Genome-wide linkage analysis in 475 HERITAGE Family Study Caucasians identified a locus on chromosome 13q for ΔVO(2)60 (LOD = 3.11). Follow-up fine mapping involved a dense marker panel of over 1,800 single-nucleotide polymorphisms (SNPs) in a 7.9-Mb region (21.1-29.1 Mb from p-terminus). Single-SNP analyses found 14 SNPs moderately associated with both ΔVO(2)60 at P ≤ 0.005 and the correlated traits of ΔWORK60 and ΔQ60 at P < 0.05. Haplotype analyses provided several strong signals (P < 1.0 × 10(-5)) for ΔVO(2)60. Overall, association analyses narrowed the target region and included potential biological candidate genes (MIPEP and SGCG). Consistent with maximal heritability estimates of 23%, up to 20% of the phenotypic variance in ΔVO(2)60 was accounted for by these SNPs. These results implicate candidate genes on chromosome 13q12 for the ability to improve submaximal exercise capacity in response to regular exercise. Submaximal exercise at 60% of maximal capacity is an exercise intensity that falls well within the range recommended in the Physical Activity Guidelines for Americans and thus has potential public health relevance.

Fine mapping of a QTL on chromosome 13 for submaximal exercise capacity training response: the HERITAGE Family Study

PubMed Central

Rice, Treva K.; Sarzynski, Mark A.; Sung, Yun Ju; Argyropoulos, George; Stütz, Adrian M.; Teran-Garcia, Margarita; Rao, D. C.; Bouchard, Claude

2014-01-01

Although regular exercise improves submaximal aerobic capacity, there is large variability in its response to exercise training. While this variation is thought to be partly due to genetic differences, relatively little is known about the causal genes. Submaximal aerobic capacity traits in the current report include the responses of oxygen consumption (ΔVO260), power output (ΔWORK60), and cardiac output (ΔQ60) at 60% of VO2max to a standardized 20-week endurance exercise training program. Genome-wide linkage analysis in 475 HERITAGE Family Study Caucasians identified a locus on chromosome 13q for ΔVO260 (LOD = 3.11). Follow-up fine mapping involved a dense marker panel of over 1,800 single-nucleotide polymorphisms (SNPs) in a 7.9-Mb region (21.1–29.1 Mb from p-terminus). Single-SNP analyses found 14 SNPs moderately associated with both ΔVO260 at P ≤ 0.005 and the correlated traits of ΔWORK60 and ΔQ60 at P < 0.05. Haplotype analyses provided several strong signals (P<1.0 × 10−5) for ΔVO260. Overall, association analyses narrowed the target region and included potential biological candidate genes (MIPEP and SGCG). Consistent with maximal heritability estimates of 23%, up to 20% of the phenotypic variance in ΔVO260 was accounted for by these SNPs. These results implicate candidate genes on chromosome 13q12 for the ability to improve submaximal exercise capacity in response to regular exercise. Submaximal exercise at 60% of maximal capacity is an exercise intensity that falls well within the range recommended in the Physical Activity Guidelines for Americans and thus has potential public health relevance. PMID:22170014

Exercise capacity in diabetes mellitus is predicted by activity status and cardiac size rather than cardiac function: a case control study.

PubMed

Roberts, Timothy J; Burns, Andrew T; MacIsaac, Richard J; MacIsaac, Andrew I; Prior, David L; La Gerche, André

2018-03-23

The reasons for reduced exercise capacity in diabetes mellitus (DM) remains incompletely understood, although diastolic dysfunction and diabetic cardiomyopathy are often favored explanations. However, there is a paucity of literature detailing cardiac function and reserve during incremental exercise to evaluate its significance and contribution. We sought to determine associations between comprehensive measures of cardiac function during exercise and maximal oxygen consumption ([Formula: see text]peak), with the hypothesis that the reduction in exercise capacity and cardiac function would be associated with co-morbidities and sedentary behavior rather than diabetes itself. This case-control study involved 60 subjects [20 with type 1 DM (T1DM), 20 T2DM, and 10 healthy controls age/sex-matched to each diabetes subtype] performing cardiopulmonary exercise testing and bicycle ergometer echocardiography studies. Measures of biventricular function were assessed during incremental exercise to maximal intensity. T2DM subjects were middle-aged (52 ± 11 years) with a mean T2DM diagnosis of 12 ± 7 years and modest glycemic control (HbA 1c 57 ± 12 mmol/mol). T1DM participants were younger (35 ± 8 years), with a 19 ± 10 year history of T1DM and suboptimal glycemic control (HbA 1c 65 ± 16 mmol/mol). Participants with T2DM were heavier than their controls (body mass index 29.3 ± 3.4 kg/m 2 vs. 24.7 ± 2.9, P = 0.001), performed less exercise (10 ± 12 vs. 28 ± 30 MET hours/week, P = 0.031) and had lower exercise capacity ([Formula: see text]peak = 26 ± 6 vs. 38 ± 8 ml/min/kg, P < 0.0001). These differences were not associated with biventricular systolic or left ventricular (LV) diastolic dysfunction at rest or during exercise. There was no difference in weight, exercise participation or [Formula: see text]peak in T1DM subjects as compared to their controls. After accounting for age, sex and body surface area in a multivariate analysis, significant positive predictors of [Formula: see text]peak were cardiac size (LV end-diastolic volume, LVEDV) and estimated MET-hours, while T2DM was a negative predictor. These combined factors accounted for 80% of the variance in [Formula: see text]peak (P < 0.0001). Exercise capacity is reduced in T2DM subjects relative to matched controls, whereas exercise capacity is preserved in T1DM. There was no evidence of sub-clinical cardiac dysfunction but, rather, there was an association between impaired exercise capacity, small LV volumes and sedentary behavior.

Incremental exercise test for the evaluation of peak oxygen consumption in paralympic swimmers.

PubMed

de Souza, Helton; DA Silva Alves, Eduardo; Ortega, Luciana; Silva, Andressa; Esteves, Andrea M; Schwingel, Paulo A; Vital, Roberto; DA Rocha, Edilson A; Rodrigues, Bruno; Lira, Fabio S; Tufik, Sergio; DE Mello, Marco T

2016-04-01

Peak oxygen consumption (VO2peak) is a fundamental parameter used to evaluate physical capacity. The objective of this study was to explore two types of incremental exercise tests used to determine VO2peak in four Paralympic swimmers: arm ergometer testing in the laboratory and testing in the swimming pool. On two different days, the VO2peak values of the four athletes were measured in a swimming pool and by a cycle ergometer. The protocols identified the VO2peak by progressive loading until the volitional exhaustion maximum was reached. The results were analyzed using the paired Student's t-test, Cohen's d effect sizes and a linear regression. The results showed that the VO2peak values obtained using the swimming pool protocol were higher (P=0.02) than those obtained by the arm ergometer (45.8±19.2 vs. 30.4±15.5; P=0.02), with a large effect size (d=3.20). When analyzing swimmers 1, 2, 3 and 4 individually, differences of 22.4%, 33.8%, 60.1% and 27.1% were observed, respectively. Field tests similar to the competitive setting are a more accurate way to determine the aerobic capacity of Paralympic swimmers. This approach provides more sensitive data that enable better direction of training, consequently facilitating improved performance.

Arterial Stiffness Measured with the Cuff Oscillometric Method Is Predictive of Exercise Capacity in Patients with Cardiac Diseases.

PubMed

Tazawa, Yasushi; Mori, Nobuyoshi; Ogawa, Yoshiko; Ito, Osamu; Kohzuki, Masahiro

2016-06-01

Arterial stiffness is widely used in assessing arteriosclerosis in the background of increased cardiovascular events. Arteriosclerosis also causes reduction in exercise capacity, which is a most important prognostic factor in patients with cardiovascular disease; however, data on the association between arterial stiffness and exercise capacity are limited. Therefore, a simple and noninvasive measurement of arterial stiffness that reflects the central circulation and exercise capacity is needed. The arterial velocity pulse index (AVI) is a parameter of arterial stiffness measurable with the cuff oscillometric method; however, the clinical utility of this method is unclear. We aimed to evaluate the trend of AVI in patients with coronary artery disease (CAD), and the association between AVI and exercise capacity. A cross-sectional study of 116 patients with cardiac disease (34 CAD and 82 non-CAD patients) was performed. Non-CAD patients were those with any cardiac diseases who did not have proven CAD. The results showed that the AVI was significantly higher in CAD patients than non-CAD patients (P < 0.05, analysis of covariance). The AVI was inversely correlated with peakVO2 (r = -0.239, P < 0.05) and was a significant explanatory variable for peakVO2 in stepwise regression analysis (β = -14.62, t = -2.5, P < 0.05). These results indicate that the AVI is strongly associated with CAD and predictive of the exercise capacity in patients with cardiac diseases. We, therefore, propose that the cuff oscillometric method is clinically useful in evaluating arterial stiffness in patients with cardiac diseases, especially CAD.

Exercise therapy for functional capacity in chronic diseases: an overview of meta-analyses of randomised controlled trials.

PubMed

Pasanen, Tero; Tolvanen, Samppa; Heinonen, Ari; Kujala, Urho M

2017-10-01

To summarise all meta-analyses of randomised controlled trials that have evaluated the effects of exercise therapy on functional capacity in patients with chronic diseases. Umbrella review of meta-analyses of randomised controlled trials. We systematically searched the CENTRAL, CINAHL, DARE, Medline, OTSeeker, PEDro, SPORTDiscus, ProQuest Nursing & Allied Health Database, Web of Science, Scopus, OpenGrey and BMC Proceedings from database inception to 1 September 2016. We included meta-analyses that compared the effects of exercise therapy with no treatment or usual care in adults with non-communicable chronic diseases and included outcomes related to functional capacity. We excluded meta-analyses with less than 100 patients. Eighty-five meta-analyses with 22 different chronic diseases were included. The exercise interventions resulted in statistically significant (p<0.05) improvements for 126 of 146 (86%) functional capacity outcomes, compared with the control group. The standardised mean differences were small in 64 (44%), moderate in 54 (37%) and large in 28 (19%) of the 146 functional capacity outcomes. The results were similar for aerobic exercise, resistance training, and aerobic and resistance training combined. There were no significant differences in serious adverse effects between the intervention and control groups in any of the meta-analyses. Exercise therapy appears to be a safe way to improve functional capacity and reduce disability in individuals with chronic disease. © 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.

Angiotensin II receptor blocker improves the lowered exercise capacity and impaired mitochondrial function of the skeletal muscle in type 2 diabetic mice.

PubMed

Takada, Shingo; Kinugawa, Shintaro; Hirabayashi, Kagami; Suga, Tadashi; Yokota, Takashi; Takahashi, Masashige; Fukushima, Arata; Homma, Tsuneaki; Ono, Taisuke; Sobirin, Mochamad A; Masaki, Yoshihiro; Mizushima, Wataru; Kadoguchi, Tomoyasu; Okita, Koichi; Tsutsui, Hiroyuki

2013-04-01

NAD(P)H oxidase-induced oxidative stress is at least in part involved with lowered exercise capacity and impaired mitochondrial function in high-fat diet (HFD)-induced diabetic mice. NAD(P)H oxidase can be activated by activation of the renin-angiotensin system. We investigated whether ANG II receptor blocker can improve exercise capacity in diabetic mice. C57BL/6J mice were fed a normal diet (ND) or HFD, and each group of mice was divided into two groups: treatment with or without olmesartan (OLM; 3 mg·kg(-1)·day(-1) in the drinking water). The following groups of mice were studied: ND, ND+OLM, HFD, and HFD+OLM (n = 10 for each group). After 8 wk, HFD significantly increased body weight, plasma glucose, and insulin compared with ND, and OLM did not affect these parameters in either group. Exercise capacity, as determined by treadmill tests, was significantly reduced in HFD, and this reduction was ameliorated in HFD+OLM. ADP-dependent mitochondrial respiration was significantly decreased, and NAD(P)H oxidase activity and superoxide production by lucigenin chemiluminescence were significantly increased in skeletal muscle from HFD, which were attenuated by OLM. There were no such effects by OLM in ND. We concluded that OLM ameliorated the decrease in exercise capacity in diabetic mice via improvement in mitochondrial function and attenuation of oxidative stress in skeletal muscle. These data may have a clinical impact on exercise capacity in the medical treatment of diabetes mellitus.

Effects of eccentric-focused and conventional resistance training on strength and functional capacity of older adults.

PubMed

Dias, Caroline Pieta; Toscan, Rafael; de Camargo, Mainara; Pereira, Evelyn Possobom; Griebler, Nathália; Baroni, Bruno Manfredini; Tiggemann, Carlos Leandro

2015-10-01

The aim of the study was to assess the effect of eccentric training using a constant load with longer exposure time at the eccentric phase on knee extensor muscle strength and functional capacity of elderly subjects in comparison with a conventional resistance training program. Twenty-six healthy elderly women (age = 67 ± 6 years) were randomly assigned to an eccentric-focused training group (ETG; n = 13) or a conventional training group (CTG; n = 13). Subjects underwent 12 weeks of resistance training twice a week. For the ETG, concentric and eccentric phases were performed using 1.5 and 4.5 s, respectively, while for CTG, each phase lasted 1.5 s. Maximum dynamic strength was assessed by the one-repetition maximum (1RM) test in the leg press and knee extension exercises, and for functional capacity, subjects performed specific tests (6-m walk test, timed up-and-go test, stair-climbing test, and chair-rising test). Both groups improved knee extension 1RM (24-26 %; p = 0.021), timed up-and-go test (11-16 %; p < 0.001), 6-m walk test (9-12 %; p = 0.004), stair-climbing test (8-13 %; p = 0.007), and chair-rising test (15-16 %; p < 0.001), but there was no significant difference between groups. In conclusion, the strategy of increasing the exposure time at the eccentric phase of movement using the same training volume and intensity does not promote different adaptations in strength or functional capacity compared to conventional resistance training in elderly woman.

Chronotropic Incompetence and its Relation to Exercise Intolerance in Chronic Obstructive Pulmonary Disease.

PubMed

Liu, Hai-Jian; Guo, Jian; Zhao, Qin-Hua; Wang, Lan; Yang, Wen-Lan; He, Jing; Gong, Su-Gang; Liu, Jin-Ming

2017-03-01

To study the relationship between chronotropic incompetence (CI) and disease severity and to assess the effect of CI on exercise capacity in patients with chronic obstructive pulmonary disease (COPD). Arterial blood gas analysis, pulmonary function test and cardiopulmonary exercise testing were conducted in 60 patients with stable COPD and 45 healthy volunteers. CI was defined using the chronotropic response index (CRI = (peak heart rate-resting heart rate) / (220-age-resting heart rate). Based on CRI, patients with COPD were divided into the normal chronotropic group (n = 23) and CI group (n = 37). CI was present in 61.7% of the patients with COPD. Exercise capacity (peak oxygen uptake as percentage of predicted value, peak VO 2 %pred), peak heart rate and CRI were significantly lower in patients with COPD than in controls. However, resting heart rate was significantly higher than in controls. FEV 1 %pred and exercise capacity were significantly decreased in the CI group when compared with those in the normotropic group. There was significant association between CRI with FEV 1 %pred and peak VO 2 %pred. Multivariate regression analysis showed that CRI and FEV 1 %pred were independent predictors of exercise capacity in patients with COPD. A cutoff of 0.74 for the CRI showed a specificity of 94.1% in predicting patients with a peak VO 2 %pred < 60%. CRI was associated with disease severity in patients with COPD. CI may be an important parameter to reflect exercise capacity in patients with COPD. Copyright © 2017 Southern Society for Clinical Investigation. Published by Elsevier Inc. All rights reserved.

An 8-Week Ketogenic Low Carbohydrate, High Fat Diet Enhanced Exhaustive Exercise Capacity in Mice.

PubMed

Ma, Sihui; Huang, Qingyi; Yada, Koichi; Liu, Chunhong; Suzuki, Katsuhiko

2018-05-25

Current fueling tactics for endurance exercise encourage athletes to ingest a high carbohydrate diet. However, athletes are not generally encouraged to use fat, the largest energy reserve in the human body. A low carbohydrate, high fat ketogenic diet (KD) is a nutritional approach ensuring that the body utilizes lipids. Although KD has been associated with weight-loss, enhanced fat utilization in muscle and other beneficial effects, there is currently no clear proof whether it could lead to performance advantage. To evaluate the effects of KD on endurance exercise capacity, we studied the performance of mice subjected to a running model after consuming KD for eight weeks. Weight dropped dramatically in KD-feeding mice, even though they ate more calories. KD-feeding mice showed enhanced running time without aggravated muscle injury. Blood biochemistry and correlation analysis indicated the potential mechanism is likely to be a keto-adaptation enhanced capacity to transport and metabolize fat. KD also showed a potential preventive effect on organ injury caused by acute exercise, although KD failed to exert protection from muscle injury. Ultimately, KD may contribute to prolonged exercise capacity.

Heart rate behavior during an exercise stress test in obese patients.

PubMed

Gondoni, L A; Titon, A M; Nibbio, F; Augello, G; Caetani, G; Liuzzi, A

2009-03-01

Heart rate (HR) response to exercise has not been fully described in the obese. We wanted to study the differences between obese and non-obese patients in HR behavior during an exercise stress test and to determine whether these differences influence exercise capacity. We studied 554 patients (318 females) who underwent a treadmill exercise test. All subjects were in sinus rhythm. Patients with ischemic heart disease, with reduced ejection fraction and patients taking drugs that interfere with HR were excluded. The population included 231 patients with BMI<30 kg/m(2) (group 1), 212 patients who were unfit and obese (group 2) and 111 patients who were trained obese (group 3). Resting HR was similar in the various groups. Peak HR, HR recovery and chronotropic index were lower in obese subjects, regardless of their fitness level. Multivariate analysis showed that HR related variables were associated with age, BMI, height, hypertension and various pharmacologic treatments, while exercise capacity was strongly dependent on HR behavior, as well as on sex, age, BMI and diabetes. Obese subjects have a marked impairment of HR behavior during exercise and in the recovery period, and the blunted increase in HR is the most important factor that influences exercise capacity.

A Cycle Ergometer Exercise Program Improves Exercise Capacity and Inspiratory Muscle Function in Hospitalized Patients Awaiting Heart Transplantation: a Pilot Study

PubMed Central

Forestieri, Patrícia; Guizilini, Solange; Peres, Monique; Bublitz, Caroline; Bolzan, Douglas W.; Rocco, Isadora S.; Santos, Vinícius B.; Moreira, Rita Simone L.; Breda, João R.; de Almeida, Dirceu R.; Carvalho, Antonio Carlos de C.; Arena, Ross; Gomes, Walter J.

2016-01-01

Objective The purpose of this study was to evaluate the effect of a cycle ergometer exercise program on exercise capacity and inspiratory muscle function in hospitalized patients with heart failure awaiting heart transplantation with intravenous inotropic support. Methods Patients awaiting heart transplantation were randomized and allocated prospectively into two groups: 1) Control Group (n=11) - conventional protocol; and 2) Intervention Group (n=7) - stationary cycle ergometer exercise training. Functional capacity was measured by the six-minute walk test and inspiratory muscle strength assessed by manovacuometry before and after the exercise protocols. Results Both groups demonstrated an increase in six-minute walk test distance after the experimental procedure compared to baseline; however, only the intervention group had a significant increase (P=0.08 and P=0.001 for the control and intervention groups, respectively). Intergroup comparison revealed a greater increase in the intervention group compared to the control (P<0.001). Regarding the inspiratory muscle strength evaluation, the intragroup analysis demonstrated increased strength after the protocols compared to baseline for both groups; statistical significance was only demonstrated for the intervention group, though (P=0.22 and P<0.01, respectively). Intergroup comparison showed a significant increase in the intervention group compared to the control (P<0.01). Conclusion Stationary cycle ergometer exercise training shows positive results on exercise capacity and inspiratory muscle strength in patients with heart failure awaiting cardiac transplantation while on intravenous inotropic support. PMID:27982348

Comparison of Watermelon and Carbohydrate Beverage on Exercise-Induced Alterations in Systemic Inflammation, Immune Dysfunction, and Plasma Antioxidant Capacity

PubMed Central

Shanely, R. Andrew; Nieman, David C.; Perkins-Veazie, Penelope; Henson, Dru A.; Meaney, Mary P.; Knab, Amy M.; Cialdell-Kam, Lynn

2016-01-01

Consuming carbohydrate- and antioxidant-rich fruits during exercise as a means of supporting and enhancing both performance and health is of interest to endurance athletes. Watermelon (WM) contains carbohydrate, lycopene, l-citrulline, and l-arginine. WM may support exercise performance, augment antioxidant capacity, and act as a countermeasure to exercise-induced inflammation and innate immune changes. Trained cyclists (n = 20, 48 ± 2 years) participated in a randomized, placebo controlled, crossover study. Subjects completed two 75 km cycling time trials after either 2 weeks ingestion of 980 mL/day WM puree or no treatment. Subjects drank either WM puree containing 0.2 gm/kg carbohydrate or a 6% carbohydrate beverage every 15 min during the time trials. Blood samples were taken pre-study and pre-, post-, 1 h post-exercise. WM ingestion versus no treatment for 2-weeks increased plasma l-citrulline and l-arginine concentrations (p < 0.0125). Exercise performance did not differ between WM puree or carbohydrate beverage trials (p > 0.05), however, the rating of perceived exertion was greater during the WM trial (p > 0.05). WM puree versus carbohydrate beverage resulted in a similar pattern of increase in blood glucose, and greater increases in post-exercise plasma antioxidant capacity, l-citrulline, l-arginine, and total nitrate (all p < 0.05), but without differences in systemic markers of inflammation or innate immune function. Daily WM puree consumption fully supported the energy demands of exercise, and increased post-exercise blood levels of WM nutritional components (l-citrulline and l-arginine), antioxidant capacity, and total nitrate, but without an influence on post-exercise inflammation and changes in innate immune function. PMID:27556488

Home-based versus center-based aerobic exercise on cardiopulmonary performance, physical function, quality of life and quality of sleep of overweight patients with chronic kidney disease.

PubMed

Aoike, Danilo Takashi; Baria, Flavia; Kamimura, Maria Ayako; Ammirati, Adriano; Cuppari, Lilian

2018-02-01

The association between chronic kidney disease (CKD) and obesity can decrease the patients' cardiopulmonary capacity, physical functioning and quality of life. The search for effective and practical alternative methods of exercise to engage patients in training programs is of great importance. Therefore, we aimed to compare the effects of home-based versus center-based aerobic exercise on the cardiopulmonary and functional capacities, quality of life and quality of sleep of overweight non-dialysis-dependent patients with CKD (NDD-CKD). Forty sedentary overweight patients CKD stages 3 and 4 were randomly assigned to an exercise group [home-based group (n = 12) or center-based exercise group (n = 13)] or to a control group (n = 15) that did not perform any exercise. Cardiopulmonary exercise test, functional capacity tests, quality of life, quality of sleep and clinical parameters were assessed at baseline, 12 and 24 weeks. The VO 2peak and all cardiopulmonary parameters evaluated were similarly improved (p < 0.05) after 12 and 24 weeks in both exercise groups. The functional capacity tests improved during the follow-up in the home-based group (p < 0.05) and reached values similar to those obtained in the center-based group. The benefits achieved in both exercise groups were also reflected in improvement of quality of life and sleep (p < 0.05). No differences were observed between the exercise groups, and no changes in any of the parameters investigated were found in the control group. Home-based aerobic training was as effective as center-based training in improving the physical and functional capabilities, quality of life and sleep in overweight NDD-CKD patients.

Impaired chronotropic and vasodilator reserves limit exercise capacity in patients with heart failure and a preserved ejection fraction.

PubMed

Borlaug, Barry A; Melenovsky, Vojtech; Russell, Stuart D; Kessler, Kristy; Pacak, Karel; Becker, Lewis C; Kass, David A

2006-11-14

Nearly half of patients with heart failure have a preserved ejection fraction (HFpEF). Symptoms of exercise intolerance and dyspnea are most often attributed to diastolic dysfunction; however, impaired systolic and/or arterial vasodilator reserve under stress could also play an important role. Patients with HFpEF (n=17) and control subjects without heart failure (n=19) generally matched for age, gender, hypertension, diabetes mellitus, obesity, and the presence of left ventricular hypertrophy underwent maximal-effort upright cycle ergometry with radionuclide ventriculography to determine rest and exercise cardiovascular function. Resting cardiovascular function was similar between the 2 groups. Both had limited exercise capacity, but this was more profoundly reduced in HFpEF patients (exercise duration 180+/-71 versus 455+/-184 seconds; peak oxygen consumption 9.0+/-3.4 versus 14.4+/-3.4 mL x kg(-1) x min(-1); both P<0.001). At matched low-level workload, HFpEF subjects displayed approximately 40% less of an increase in heart rate and cardiac output and less systemic vasodilation (all P<0.05) despite a similar rise in end-diastolic volume, stroke volume, and contractility. Heart rate recovery after exercise was also significantly delayed in HFpEF patients. Exercise capacity correlated with the change in cardiac output, heart rate, and vascular resistance but not end-diastolic volume or stroke volume. Lung blood volume and plasma norepinephrine levels rose similarly with exercise in both groups. HFpEF patients have reduced chronotropic, vasodilator, and cardiac output reserve during exercise compared with matched subjects with hypertensive cardiac hypertrophy. These limitations cannot be ascribed to diastolic abnormalities per se and may provide novel therapeutic targets for interventions to improve exercise capacity in this disorder.

High-intensity exercise training increases the diversity and metabolic capacity of the mouse distal gut microbiota during diet-induced obesity

PubMed Central

Denou, Emmanuel; Marcinko, Katarina; Surette, Michael G.; Steinberg, Gregory R.

2016-01-01

Diet and exercise underpin the risk of obesity-related metabolic disease. Diet alters the gut microbiota, which contributes to aspects of metabolic disease during obesity. Repeated exercise provides metabolic benefits during obesity. We assessed whether exercise could oppose changes in the taxonomic and predicted metagenomic characteristics of the gut microbiota during diet-induced obesity. We hypothesized that high-intensity interval training (HIIT) would counteract high-fat diet (HFD)-induced changes in the microbiota without altering obesity in mice. Compared with chow-fed mice, an obesity-causing HFD decreased the Bacteroidetes-to-Firmicutes ratio and decreased the genetic capacity in the fecal microbiota for metabolic pathways such as the tricarboxylic acid (TCA) cycle. After HFD-induced obesity was established, a subset of mice were HIIT for 6 wk, which increased host aerobic capacity but did not alter body or adipose tissue mass. The effects of exercise training on the microbiota were gut segment dependent and more extensive in the distal gut. HIIT increased the alpha diversity and Bacteroidetes/Firmicutes ratio of the distal gut and fecal microbiota during diet-induced obesity. Exercise training increased the predicted genetic capacity related to the TCA cycle among other aspects of metabolism. Strikingly, the same microbial metabolism indexes that were increased by exercise were all decreased in HFD-fed vs. chow diet-fed mice. Therefore, exercise training directly opposed some of the obesity-related changes in gut microbiota, including lower metagenomic indexes of metabolism. Some host and microbial pathways appeared similarly affected by exercise. These exercise- and diet-induced microbiota interactions can be captured in feces. PMID:27117007

High-intensity exercise training increases the diversity and metabolic capacity of the mouse distal gut microbiota during diet-induced obesity.

PubMed

Denou, Emmanuel; Marcinko, Katarina; Surette, Michael G; Steinberg, Gregory R; Schertzer, Jonathan D

2016-06-01

Diet and exercise underpin the risk of obesity-related metabolic disease. Diet alters the gut microbiota, which contributes to aspects of metabolic disease during obesity. Repeated exercise provides metabolic benefits during obesity. We assessed whether exercise could oppose changes in the taxonomic and predicted metagenomic characteristics of the gut microbiota during diet-induced obesity. We hypothesized that high-intensity interval training (HIIT) would counteract high-fat diet (HFD)-induced changes in the microbiota without altering obesity in mice. Compared with chow-fed mice, an obesity-causing HFD decreased the Bacteroidetes-to-Firmicutes ratio and decreased the genetic capacity in the fecal microbiota for metabolic pathways such as the tricarboxylic acid (TCA) cycle. After HFD-induced obesity was established, a subset of mice were HIIT for 6 wk, which increased host aerobic capacity but did not alter body or adipose tissue mass. The effects of exercise training on the microbiota were gut segment dependent and more extensive in the distal gut. HIIT increased the alpha diversity and Bacteroidetes/Firmicutes ratio of the distal gut and fecal microbiota during diet-induced obesity. Exercise training increased the predicted genetic capacity related to the TCA cycle among other aspects of metabolism. Strikingly, the same microbial metabolism indexes that were increased by exercise were all decreased in HFD-fed vs. chow diet-fed mice. Therefore, exercise training directly opposed some of the obesity-related changes in gut microbiota, including lower metagenomic indexes of metabolism. Some host and microbial pathways appeared similarly affected by exercise. These exercise- and diet-induced microbiota interactions can be captured in feces. Copyright © 2016 the American Physiological Society.

Comparison of Watermelon and Carbohydrate Beverage on Exercise-Induced Alterations in Systemic Inflammation, Immune Dysfunction, and Plasma Antioxidant Capacity.

PubMed

Shanely, R Andrew; Nieman, David C; Perkins-Veazie, Penelope; Henson, Dru A; Meaney, Mary P; Knab, Amy M; Cialdell-Kam, Lynn

2016-08-22

Consuming carbohydrate- and antioxidant-rich fruits during exercise as a means of supporting and enhancing both performance and health is of interest to endurance athletes. Watermelon (WM) contains carbohydrate, lycopene, l-citrulline, and l-arginine. WM may support exercise performance, augment antioxidant capacity, and act as a countermeasure to exercise-induced inflammation and innate immune changes. Trained cyclists (n = 20, 48 ± 2 years) participated in a randomized, placebo controlled, crossover study. Subjects completed two 75 km cycling time trials after either 2 weeks ingestion of 980 mL/day WM puree or no treatment. Subjects drank either WM puree containing 0.2 gm/kg carbohydrate or a 6% carbohydrate beverage every 15 min during the time trials. Blood samples were taken pre-study and pre-, post-, 1 h post-exercise. WM ingestion versus no treatment for 2-weeks increased plasma l-citrulline and l-arginine concentrations (p < 0.0125). Exercise performance did not differ between WM puree or carbohydrate beverage trials (p > 0.05), however, the rating of perceived exertion was greater during the WM trial (p > 0.05). WM puree versus carbohydrate beverage resulted in a similar pattern of increase in blood glucose, and greater increases in post-exercise plasma antioxidant capacity, l-citrulline, l-arginine, and total nitrate (all p < 0.05), but without differences in systemic markers of inflammation or innate immune function. Daily WM puree consumption fully supported the energy demands of exercise, and increased post-exercise blood levels of WM nutritional components (l-citrulline and l-arginine), antioxidant capacity, and total nitrate, but without an influence on post-exercise inflammation and changes in innate immune function.

Acute recovery from exercise in people with multiple sclerosis: an exploratory study on the effect of exercise intensities.

PubMed

Collett, Johnny; Meaney, Andy; Howells, Ken; Dawes, Helen

2017-03-01

Purpose A better understanding of how people with multiple sclerosis (pwMS) recover from exercise may help inform interventions. Methods We explored physiological and perceptual responses following exercise of different intensities, using a crossover exposure-response design, in 14 adults with multiple sclerosis (MS) and 9 controls. A cycling exercise test determined maximum capacity (Wpeak). Participants then performed 20-min exercise sessions relative to Wpeak (random order separated by 7 days): (1) 45% and (2) 60% continuous cycling and (3) 90% intermittent cycling (30 s cycling, 30 s rest). During a 45-min recovery period, tympanic temperature (Temp°C), exertion in breathing (RPEbr) and legs (RPEleg), and cortical excitability (MEParea) were measured. Results Eleven pwMS and eight controls completed the study. Controls performed better on the exercise test (p < 0.05), thus more absolute work during subsequent sessions. PwMS took longer to recover RPEleg with recovery time increasing with intensity (45%-6 min; 60%-15 min; 90%-35 min) and correlating with Temp°C. MEParea was significantly depressed in both groups at 45% and 60% (p < 0.001), in the MS group this also correlated with RPEleg. Conclusions Feelings of leg exertion may persist after exercise in some pwMS, especially at high intensities. This may relate to body temperature and, after continuous exercise, cortical excitability. These results support considering the recovery period post exercise and provide an insight into potential correlates of post-exercise fatigue. Implications for Rehabilitation A better understanding of how pwMS recover following exercise may help inform exercise prescription a long side fatigue management. This study showed that, in pwMS, the time taken to recover from feelings of leg fatigue increased with the intensity of the exercise session rather that total work performed and was related to increase in body temperature. The results of this relatively small study support the need to consider a recovery period after exercise and provide an insight into potential physiological correlates.

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.

Evaluation of Maximal Oxygen Uptake (V02max) and Submaximal Estimates of VO2max Before, During and After Long Duration ISS Missions

NASA Technical Reports Server (NTRS)

Moore, Alan; Evetts, Simon; Feiveson, Alan; Lee, Stuart; McCleary, Frank; Platts, Steven

2009-01-01

NASA's Human Research Program Integrated Research Plan (HRP-47065) serves as a road-map identifying critically needed information for future space flight operations (Lunar, Martian). VO2max (often termed aerobic capacity) reflects the maximum rate at which oxygen can be taken up and utilized by the body during exercise. Lack of in-flight and immediate postflight VO2max measurements was one area identified as a concern. The risk associated with not knowing this information is: Unnecessary Operational Limitations due to Inaccurate Assessment of Cardiovascular Performance (HRP-47065).

Evaluation of exercise capacity after severe stroke using robotics-assisted treadmill exercise: a proof-of-concept study.

PubMed

Stoller, O; de Bruin, E D; Schindelholz, M; Schuster, C; de Bie, R A; Hunt, K J

2013-01-01

Robotics-assisted treadmill exercise (RATE) with focus on motor recovery has become popular in early post-stroke rehabilitation but low endurance for exercise is highly prevalent in these individuals. This study aimed to develop an exercise testing method using robotics-assisted treadmill exercise to evaluate aerobic capacity after severe stroke. Constant load testing (CLT) based on body weight support (BWS) control, and incremental exercise testing (IET) based on guidance force (GF) control were implemented during RATE. Analyses focussed on step change, step response kinetics, and peak performance parameters of oxygen uptake. Three subjects with severe motor impairment 16-23 days post-stroke were included. CLT yielded reasonable step change values in oxygen uptake, whereas response kinetics of oxygen uptake showed low goodness of fit. Peak performance parameters were not obtained during IET. Exercise testing in post-stroke individuals with severe motor impairments using a BWS control strategy for CLT is deemed feasible and safe. Our approach yielded reasonable results regarding cardiovascular performance parameters. IET based on GF control does not provoke peak cardiovascular performance due to uncoordinated walking patterns. GF control needs further development to optimally demand active participation during RATE. The findings warrant further research regarding the evaluation of exercise capacity after severe stroke.

Beet Root Juice: An Ergogenic Aid for Exercise and the Aging Brain.

PubMed

Petrie, Meredith; Rejeski, W Jack; Basu, Swati; Laurienti, Paul J; Marsh, Anthony P; Norris, James L; Kim-Shapiro, Daniel B; Burdette, Jonathan H

2017-09-01

Exercise has positive neuroplastic effects on the aging brain. It has also been shown that ingestion of beet root juice (BRJ) increases blood flow to the brain and enhances exercise performance. Here, we examined whether there are synergistic effects of BRJ and exercise on neuroplasticity in the aging brain. Peak metabolic equivalent (MET) capacity and resting-state magnetic resonance imaging functional brain network organization are reported on 26 older (mean age = 65.4 years) participants randomly assigned to 6 weeks of exercise + BRJ or exercise + placebo. Somatomotor community structure consistency was significantly enhanced in the exercise + BRJ group following the intervention (MBRJ = -2.27, SE = 0.145, MPlacebo = -2.89, SE = 0.156, p = .007). Differences in second-order connections between the somatomotor cortex and insular cortex were also significant; the exercise + BRJ group (M = 3.28, SE = 0.167) had a significantly lower number of connections than exercise + placebo (M = 3.91, SE = 0.18, p = .017) following the intervention. Evaluation of peak MET capacity revealed a trend for the exercise + BRJ group to have higher MET capacity following the intervention. Older adults who exercised and consumed BRJ demonstrated greater consistency within the motor community and fewer secondary connections with the insular cortex compared with those who exercised without BRJ. The exercise + BRJ group had brain networks that more closely resembled those of younger adults, showing the potential enhanced neuroplasticity conferred by combining exercise and BRJ consumption. © The Author 2016. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

High-Intensity Interval Training for Severe Left Ventricular Dysfunction Treated with Left Ventricular Assist Device.

PubMed

Ugata, Yusuke; Wada, Hiroshi; Sakakura, Kenichi; Ibe, Tatsuro; Ito, Miyuki; Ikeda, Nahoko; Fujita, Hideo; Momomura, Shin-Ichi

2018-01-27

Aerobic training based on anaerobic threshold (AT) is well-known to improve cardiac function, exercise capacity, and long-term outcomes of patients with heart failure. Recent reports suggested that high-intensity interval training (HIIT) for patients with cardiovascular disease may improve cardiopulmonary exercise capacity. We present a 61-year-old male patient of severe left ventricular dysfunction with left ventricular assisted device (LVAD). Following HIIT for 8 weeks, exercise capacity and muscle strength have improved without worsening left ventricular function. Our case showed the possibility that HIIT was feasible and effective even in patients with LVAD.

Effect of energy drink dose on exercise capacity, heart rate recovery and heart rate variability after high-intensity exercise.

PubMed

An, Sang Min; Park, Jong Suk; Kim, Sang Ho

2014-03-01

The purpose of this research was to investigate the effects of exercise capacity, heart rate recovery and heart rate variability after high-intensity exercise on caffeine concentration of energy drink. The volunteers for this study were 15 male university student. 15 subjects were taken basic physical examinations such as height, weight and BMI before the experiment. Primary tests were examined of VO2max per weight of each subjects by graded exercise test using Bruce protocol. Each of five subject was divided 3 groups (CON, ECGⅠ, ECGⅡ) by matched method based on weight and VO2max per weight what gained of primary test for minimize the differences of exercise capacity and ingestion of each groups. For the secondary tests, the groups of subjects were taken their materials before and after exercise as a blind test. After the ingestion, subjects were experimented on exercise test of VO2max 80% by treadmill until the all-out. Heart rate was measured by 1minute interval, and respiratory variables were analyzed VO2, VE, VT, RR and so on by automatic respiratory analyzer. And exercise exhaustion time was determined by stopwatch. Moreover, HRV was measured after exercise and recovery 3 min. Among the intake groups, ECGⅡ was showed the longest of exercise exhaustion time more than CON group (p = .05). Result of heart rate during exercise according to intake groups, there was significant differences of each time (p < .001), however, not significant differences of each groups and group verse time (p > .05). Result of RPE during exercise according to intake groups, there was significant differences of each time (p < .001), however, not significant differences of each groups and group verse time (p > .05). In conclusion, EDGⅡ showed the significant increase of exercise exhaustion time more than CON group (p=.05) and not significant differences in HR, RPE, RER, HRV, HRR, blood pressure (p > .05). Therefore, 2.5 mg/kg(-1) ingestion of energy drink might be positive effect to increase exercise performance capacity without side-effect in cardiovascular disease.

Assessment and monitoring of flow limitation and other parameters from flow/volume loops.

PubMed

Dueck, R

2000-01-01

Flow/volume (F/V) spirometry is routinely used for assessing the type and severity of lung disease. Forced vital capacity (FVC) and timed vital capacity (FEV1) provide the best estimates of airflow obstruction in patients with asthma, chronic obstructive pulmonary disease (COPD) and emphysema. Computerized spirometers are now available for early home recognition of asthma exacerbation in high risk patients with severe persistent disease, and for recognition of either infection or rejection in lung transplant patients. Patients with severe COPD may exhibit expiratory flow limitation (EFL) on tidal volume (VT) expiratory F/V (VTF/V) curves, either with or without applying negative expiratory pressure (NEP). EFL results in dynamic hyperinflation and persistently raised alveolar pressure or intrinsic PEEP (PEEPi). Hyperinflation and raised PEEPi greatly enhance dyspnea with exertion through the added work of the threshold load needed to overcome raised pleural pressure. Esophageal (pleural) pressure monitoring may be added to VTF/V loops for assessing the severity of PEEPi: 1) to optimize assisted ventilation by mask or via endotracheal tube with high inspiratory flow rates to lower I:E ratio, and 2) to assess the efficacy of either pressure support ventilation (PSV) or low level extrinsic PEEP in reducing the threshold load of PEEPi. Intraoperative tidal volume F/V loops can also be used to document the efficacy of emphysema lung volume reduction surgery (LVRS) via disappearance of EFL. Finally, the mechanism of ventilatory constraint can be identified with the use of exercise tidal volume F/V loops referenced to maximum F/V loops and static lung volumes. Patients with severe COPD show inspiratory F/V loops approaching 95% of total lung capacity, and flow limitation over the entire expiratory F/V curve during light levels of exercise. Surprisingly, patients with a history of congestive heart failure may lower lung volume towards residual volume during exercise, thereby reducing airway diameter and inducing expiratory flow limitation.

The Influence of Type 1 Diabetes Mellitus on Pulmonary Function and Exercise Capacity - Results from the Study of Health in Pomerania (SHIP).

PubMed

Stubbe, Beate; Schipf, Sabine; Schäper, Christoph; Felix, Stephan B; Steveling, Antje; Nauck, Matthias; Völzke, Henry; Wallaschofski, Henri; Friedrich, Nele; Ewert, Ralf; Ittermann, Till; Gläser, Sven

2017-01-01

Background: Diabetes mellitus Type 1 (T1DM) is associated with metabolic and microvascular diseases as part of a multi-organ and multi-systemic disorder. The dense network of capillary vessels in the lungs may change during the course of the development of microangiopathy. The connective tissue as well as alveoli may be subjected to non-enzymatic glycosylation of proteins which may in turn affect pulmonary function. Previous studies investigating lung function in patients with type 1 diabetes have only been performed on small numbers of patients. Our study is based on population data of the Study of Health in Pomerania (SHIP). Objective: To investigate the influence of metabolic control on pulmonary system function and to establish a decreased pulmonary system function as a late complication of T1DM in a population based setting. Methods: The study is a case matched study with multiple controls based on participants with T1DM (SHIP-DM-1, n=73) and non-diabetics (SHIP-1, n=292) from the population based study of Pomerania. Data on lung function and exercise performance stratified by age, sex, body mass index and smoking habits in participants with T1DM and without diabetes were matched. Results: Participants with T1DM showed a significantly lower total lung capacity, residual volume and forced vital capacity. The transfer factor for carbon monoxide, the maximum power output and oxygen uptake during exercise were significantly decreased in comparison to the general population without diabetes. Conclusion: The pattern of abnormal pulmonary function as observed in the present study with a reduction in lung volume parameters and reduced oxygen uptake in participants with T1DM suggests a restrictive type of lung disease caused by an intrinsic lung tissue derangement as well as pulmonary microangiopathy. © Georg Thieme Verlag KG Stuttgart · New York.

Randomized Controlled Trial to Examine the Impact of Aquatic Exercise Training on Functional Capacity, Balance, and Perceptions of Fatigue in Female Patients With Multiple Sclerosis.

PubMed

Kargarfard, Mehdi; Shariat, Ardalan; Ingle, Lee; Cleland, Joshua A; Kargarfard, Mina

2018-02-01

To assess the effects of an 8-week aquatic exercise training program on functional capacity, balance, and perceptions of fatigue in women with multiple sclerosis (MS). Randomized controlled design. Referral center of an MS society. Women (N=32; mean age ± SD, 36.4±8.2y) with diagnosed relapsing-remitting MS. After undergoing baseline testing by a neurologist, participants were allocated to either an intervention (aquatic training program, n=17) or a control group (n=15). The intervention consisted of an 8-week aquatic training program (3 supervised training sessions per week; session duration, 45-60min; 50%-75% estimated maximum heart rate). Six-minute walk test (6-MWT), balance (Berg Balance Scale [BBS]), and perceptions of fatigue (Modified Fatigue Impact Scale; [MFIS]) at baseline and after the 8-week intervention. Differences over time between the experimental and control groups were assessed by a 2×2 (group by time) repeated-measures analysis of variance. Thirty-two women completed the 8-week aquatic training intervention (experimental group, n=17; control group, n=15). All outcome measures improved in the experimental group: 6-MWT performance (pretest mean ± SD, 451±58m; posttest mean ± SD, 503±57m; P<.001); BBS (pretest mean ± SD, 53.59±1.70; posttest mean ± SD, 55.18±1.18; P<.001), and MFIS (pretest mean ± SD, 43.1±14.6; posttest mean ± SD, 32.8±5.9; P<.01). A significant group-by-time interaction was evident between the experimental and control groups for 6-MWT (P<.001, partial eta 2 [η p 2 ]=.551), BBS (P<.001, η p 2 =.423), and MFIS (P<.001, η p 2 =.679). Aquatic exercise training improved functional capacity, balance, and perceptions of fatigue in women with MS. Copyright © 2017 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Number of thoracotomies predicts impairment in lung function and exercise capacity in patients with congenital heart disease.

PubMed

Müller, Jan; Ewert, Peter; Hager, Alfred

2018-01-01

Many patients with congenital heart disease (CHD) require surgery to ensure survival into adulthood. But history of previous thoracotomies is associated with respiratory muscle weakness, impairments in chest wall compliance, and moderately to severely impaired lung function. This study evaluated the impact of thoracotomies on functional outcome in patients with CHD. In total 1372 adolescents and adults with CHD (32.4±11.5 years, 624 female), who underwent spirometry and cardiopulmonary exercise testing in our institution from January 2010 to August 2015, were analyzed. After adjusting for confounding variables, with every thoracotomy the prevalence for a restrictive ventilatory pattern increased by 1.8-fold (CI: 1.606-2.050; p<0.001). The number of thoracotomies had no direct influence on an impaired exercise capacity in a multivariate model, but with every percentage point increase in forced vital capacity probability of impaired exercise capacity diminished (OR: 0.944, CI: 0.933-0.955, p<0.001). There was a moderate correlation of forced vital capacity and peak oxygen uptake (r=0.464, p<0.001). After a follow-up of 2.1±1.6 years 21 patients had died. Survival was only related to age (p<0.001) and peak oxygen uptake (p<0.001) after considering together with thoracotomies, oxygen saturation at rest and forced vital capacity in a multivariate model. Independent of CHD complexity and other risk factors, multiple thoracotomies lead to restrictive lung pattern. It could be suggested that those limitations in forced vital capacity contribute to impairments in exercise capacity, which turned out to be the strongest predictor for survival. Copyright © 2017 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

Oxygen uptake and body composition after aquatic physical training in women with fibromyalgia: a randomized controlled trial.

PubMed

Andrade, Carolina P; Zamunér, Antonio R; Forti, Meire; França, Thalita F; Tamburús, Nayara Y; Silva, Ester

2017-10-01

Aquatic physical training (APT) has been strongly recommended to improve symptoms in fibromyalgia syndrome (FMS). However, its effects on body composition and whether lean body mass (LBM) directly influences the aerobic functional capacity of this population are still not clear. To investigate whether APT can help improve body composition and increase the aerobic functional capacity in women with FMS, and whether oxygen uptake (VO2) related to LBM can better quantify the functional capacity of this population. Randomized controlled trial. The Federal University of São Carlos, São Paulo, Brazil. Fifty-four women with FMS were randomly assigned to trained group (TG, N.=27) or control group (CG, N.=27). All women underwent cardiopulmonary exercise test (CPET) to assess oxygen consumption at ventilatory anaerobic threshold (VAT) and at peak exercise, and also to assess body composition. The TG was submitted to APT program, held twice a week for 16 weeks. The exercise intensity was adapted throughout the sessions in order to keep heart rate and ratings of perceived exertion achieved at VAT. After APT, body composition was not significantly different between groups (TG and CG). In VAT only TG showed increased VO2 related to LBM, since in peak CPET, VO2 in absolute units, VO2 related to total body mass (TBM), VO2 related to LBM and power showed significant differences. Significant difference between VO2 related to TBM and VO2 related to baseline LBM and after 16 weeks of follow-up, both in VAT as in peak CPET in both groups. Significant difference between VO2 related to TBM and VO2 related to LBM at VAT and at peak CPET in both groups at baseline and after 16 weeks of follow-up was observed. APT with standardized intensities did not cause significant changes in body composition, but was effective in promoting increased VO2 at peak CPET in women with FMS. However, VO2 related to LBM more accurately reflected changes in aerobic functional capacity at VAT level after to APT. APT with standardized intensities at VAT level is of great interest, since VAT reflects better aerobic functional capacity of patients with FMS than maximum VO2.

Are there sex differences in the capillary blood volume and diffusing capacity response to exercise?

PubMed

Bouwsema, Melissa M; Tedjasaputra, Vincent; Stickland, Michael K

2017-03-01

Previous work suggests that women may exhibit a greater respiratory limitation in exercise compared with height-matched men. Diffusion capacity (Dl CO ) increases with incremental exercise, and the smaller lungs of women may limit membrane diffusing capacity (Dm) and pulmonary capillary blood volume (Vc) in response to the increased oxygen demand. We hypothesized that women would have lower Dl CO , Dl CO relative to cardiac output (Dl CO /Q̇), Dm, Vc, and pulmonary transit time, secondary to lower Vc at peak exercise. Sixteen women (112 ± 12% predicted relative V̇o 2peak ) and sixteen men (118 ± 22% predicted relative V̇o 2peak ) were matched for height and weight. Hemoglobin-corrected diffusing capacity (Dl CO ), Vc, and Dm were determined via the multiple-[Formula: see text] Dl CO technique at rest and during incremental exercise up to 90% of V̇o 2peak Both groups increased Dl CO , Vc, and Dm with exercise intensity, but women had 20% lower Dl CO ( P < 0.001), 18% lower Vc ( P = 0.002), and 22% lower Dm ( P < 0.001) compared with men across all workloads, and neither group exhibited a plateau in Vc. When expressed relative to alveolar volume (Va), the between-sex difference was eliminated. The drop in Dl CO /Q̇ was proportionally less in women than men, and mean pulmonary transit time did not drop below 0.3 s in either group. Women demonstrate consistently lower Dl CO , Vc, and Dm compared with height-matched men during exercise; however, these differences disappear with correction for lung size. These results suggest that after differences in lung volume are accounted for there is no intrinsic sex difference in the Dl CO , Vc, or Dm response to exercise. NEW & NOTEWORTHY Women demonstrate lower diffusing capacity-to-cardiac output ratio (Dl CO /Q̇), pulmonary capillary blood volume (Vc), and membrane diffusing capacity (Dm) compared with height-matched men during exercise. However, these differences disappear after correction for lung size. The drop in Dl CO /Q̇ was proportionally less in women, and pulmonary transit time did not drop below 0.3 s in either group. After differences in lung volume are accounted for, there is no intrinsic sex difference in Dl CO , Vc, or Dm response to exercise. Copyright © 2017 the American Physiological Society.

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.

Effects of carbohydrate ingestion 15 min before exercise on endurance running capacity.

PubMed

Tokmakidis, Savvas P; Karamanolis, Ioannis A

2008-06-01

This study examined the effects of pre-exercise carbohydrate ingestion on exercise metabolism and endurance running capacity. Eleven active subjects (VO(2) (max) 49.0 +/- 1.7 mL x kg(-1) x min(-1), mean +/- SE) performed two exercise trials 15 min after ingesting glucose (G; 1 g x kg body mass(-1)) and placebo (CON). Each subject ran on a level treadmill for 5 min at 60%, 45 min at 70%, and then at 80% of VO(2) (max) until exhaustion. Serum glucose and plasma insulin reached their peak concentrations (p < 0.01) 15 min after glucose ingestion and declined at the onset of exercise. Serum glycerol concentrations were lower (p < 0.01) in the G trial than in the CON trial after 30 min of exercise to exhaustion. In addition, after 45 min of exercise to exhaustion, the levels of free fatty acids were lower in G than in CON (p < 0.05). No differences were observed in carbohydrate oxidation rates during exercise between treatments (G, 2.53 +/- 0.08 g x min(-1); CON, 2.40 +/- 0.09 g x min(-1)). Time to exhaustion was 12.8% longer in G (p < 0.01) than in CON. These results suggest that glucose ingestion 15 min before prolonged exercise provides an additional carbohydrate source to the exercising muscle, thus improving endurance running capacity.

Hyperandrogenism Enhances Muscle Strength After Progressive Resistance Training, Independent of Body Composition, in Women With Polycystic Ovary Syndrome.

PubMed

Kogure, Gislaine S; Silva, Rafael C; Miranda-Furtado, Cristiana L; Ribeiro, Victor B; Pedroso, Daiana C C; Melo, Anderson S; Ferriani, Rui A; Reis, Rosana Maria Dos

2018-06-20

Kogure, GS, Silva, RC, Miranda-Furtado, CL, Ribeiro, VB, Pedroso, DCC, Melo, AS, Ferriani, RA, and Reis, RMd. Hyperandrogenism enhances muscle strength after progressive resistance training, independent of body composition, in women with polycystic ovary syndrome. J Strength Cond Res XX(X): 000-000, 2018-The effects of resistance exercise on muscle strength, body composition, and increase in cross-sectional area of skeletal muscle (hypertrophy) were evaluated in women with polycystic ovary syndrome (PCOS). This case-control study included 45 PCOS and 52 non-PCOS women, with age between 18-37 years and body mass index of 18-39.9 kg·m. Subjects performed a program of progressive resistance training (PRT), 3 times per week for 4 months. Biochemical characteristics were measured before and after PRT. Muscle strength evaluated by 1 maximum repetition test and body composition and hypertrophy indicator, evaluated by anthropometry, were measured at baseline, at 8 weeks, and at 16 weeks after PRT. Progressive resistance training produced an increase in maximum strength (bench press, p = 0.04; leg extension, p = 0.04) in the PCOS group; however, no changes were observed in body composition between groups. Concentration of testosterone decreased in both PCOS and non-PCOS groups (p < 0.01, both) after PRT, as well as glycemia (PCOS, p = 0.01; non-PCOS, p = 0.02) and body fat percentage (p < 0.01, both). An increase in hypertrophy indicators, lean body mass (LBM), and maximum strength on all exercises was observed in both PCOS and non-PCOS groups (p < 0.01). This training protocol promoted increases in muscle strength in PCOS women, and improved hyperandrogenism and body composition by decreasing body fat and increasing LBM and muscle strength in both PCOS and non-PCOS groups. Therefore, it is suggested that resistance exercise programs could promote health and fitness in women of reproductive age, especially functional capacity of strength those with PCOS.

Exercise intervention for the treatment of trismus in head and neck cancer.

PubMed

Pauli, Nina; Fagerberg-Mohlin, Bodil; Andréll, Paulin; Finizia, Caterina

2014-04-01

The aim of this study was to investigate the impact of structured exercise with jaw mobilizing devices on trismus and its effect on trismus symptomatology and health-related quality of life (HRQL) in head and neck (H&N) cancer patients. Fifty patients with H&N cancer and trismus, i.e. maximum interincisal opening (MIO) ≤ 35 mm participated in a structured intervention program with jaw exercise. The patients in the intervention group underwent a 10-week exercise program with regular follow-up. A control group comprising of 50 patients with trismus and H&N cancer were matched to the intervention group according to gender, tumor location, tumor stage, comorbidity and age. HRQL and trismus-related symptoms were assessed. The mean MIO improvement was 6.4 mm (4.8-8.0) and 0.7 (-0.3-1.7) mm in the intervention group and control group respectively, three months post-intervention commencement (p < 0.001). The intervention group demonstrated a statistically significant improvement in Role functioning, Social functioning and Global quality of life (EORTC QLQ C30) and in all Gothenburg Trismus Questionnaire (GTQ) domains, i.e. jaw-related problems (p < 0.001), eating limitation (p < 0.05) and muscular tension (p < 0.001). We found that a structured jaw exercise program was effective and improved the mouth opening capacity significantly. The objective effect on trismus (MIO) was also reflected in the patient-reported outcome questionnaires where the patients who underwent the structured exercise program after cancer treatment reported improvements in HRQL and less trismus-related symptoms compared to the control group.

Impact of error self-perception of aerobic capacity in the safety and efficacy of the lifeguards.

PubMed

Prieto, Jose A; Nistal, Paloma; Méndez, David; Abelairas-Gomez, Cristian; Barcala-Furelos, Roberto

2016-01-01

The strong physical demands that are required of lifeguards during rescues also require an accurate self-perception of one's fitness level to be able to regulate the intensity of effort. The aim of this study was to determine the real aerobic capacity (RAC) and to compare it with two self-reported measurements: subjective appraisal of aerobic capacity (SAAC) and appraisal of physical exercise (APE). Fifty-two professional lifeguards were included in the study. For an objective assessment of RAC, the lifeguards' maximum oxygen uptake (VO2max) values were measured during treadmill stress tests. A fitness assessment questionnaire was used to obtain the SAAC and APE values. We found a statistically significant association between the APE and RAC variables in the contingency analysis (p < 0.001). In total, 93.7% of the lifeguards who obtained a VO2max value below 43 ml kg(-1) min(-1) considered their aerobic capacity to be high or very high. This self-perception error of true aerobic capacity could lead to premature fatigue during a rescue, endangering both the lifeguard's life and the life of the victim. These data may help lifeguards and beach managers to become aware of the need to know lifeguards' true physical conditions through testing and structured training programs.

Substantive hemodynamic and thermal strain upon completing lower-limb hot-water immersion; comparisons with treadmill running.

PubMed

Thomas, Kate N; van Rij, André M; Lucas, Samuel J E; Gray, Andrew R; Cotter, James D

2016-01-01

Exercise induces arterial flow patterns that promote functional and structural adaptations, improving functional capacity and reducing cardiovascular risk. While heat is produced by exercise, local and whole-body passive heating have recently been shown to generate favorable flow profiles and associated vascular adaptations in the upper limb. Flow responses to acute heating in the lower limbs have not yet been assessed, or directly compared to exercise, and other cardiovascular effects of lower-limb heating have not been fully characterized. Lower-limb heating by hot-water immersion (30 min at 42°C, to the waist) was compared to matched-duration treadmill running (65-75% age-predicted heart rate maximum) in 10 healthy, young adult volunteers. Superficial femoral artery shear rate assessed immediately upon completion was increased to a greater extent following immersion (mean ± SD: immersion +252 ± 137% vs. exercise +155 ± 69%, interaction: p = 0.032), while superficial femoral artery flow-mediated dilation was unchanged in either intervention. Immersion increased heart rate to a lower peak than during exercise (immersion +38 ± 3 beats·min -1 vs. exercise +87 ± 3 beats·min -1 , interaction: p < 0.001), whereas only immersion reduced mean arterial pressure after exposure (-8 ± 3 mmHg, p = 0.012). Core temperature increased twice as much during immersion as exercise (+1.3 ± 0.4°C vs. +0.6 ± 0.4°C, p < 0.001). These data indicate that acute lower-limb hot-water immersion has potential to induce favorable shear stress patterns and cardiovascular responses within vessels prone to atherosclerosis. Whether repetition of lower-limb heating has long-term beneficial effects in such vasculature remains unexplored.

Pioglitazone ameliorates the lowered exercise capacity and impaired mitochondrial function of the skeletal muscle in type 2 diabetic mice.

PubMed

Takada, Shingo; Hirabayashi, Kagami; Kinugawa, Shintaro; Yokota, Takashi; Matsushima, Shouji; Suga, Tadashi; Kadoguchi, Tomoyasu; Fukushima, Arata; Homma, Tsuneaki; Mizushima, Wataru; Masaki, Yoshihiro; Furihata, Takaaki; Katsuyama, Ryoichi; Okita, Koichi; Tsutsui, Hiroyuki

2014-10-05

We have reported that exercise capacity is reduced in high fat diet (HFD)-induced diabetic mice, and that this reduction is associated with impaired mitochondrial function in skeletal muscle (SKM). However, it remains to be clarified whether the treatment of diabetes ameliorates the reduced exercise capacity. Therefore, we examined whether an insulin-sensitizing drug, pioglitazone, could improve exercise capacity in HFD mice. C57BL/6J mice were fed a normal diet (ND) or HFD, then treated with or without pioglitazone (3 mg/kg/day) to yield the following 4 groups: ND+vehicle, ND+pioglitazone, HFD+vehicle, and HFD+pioglitazone (n=10 each). After 8 weeks, body weight, plasma glucose, and insulin in the HFD+vehicle were significantly increased compared to the ND+vehicle group. Pioglitazone normalized the insulin levels in HFD-fed mice, but did not affect the body weight or plasma glucose. Exercise capacity determined by treadmill tests was significantly reduced in the HFD+vehicle, and this reduction was almost completely ameliorated in HFD+pioglitazone mice. ADP-dependent mitochondrial respiration, complex I and III activities, and citrate synthase activity were significantly decreased in the SKM of the HFD+vehicle animals, and these decreases were also attenuated by pioglitazone. NAD(P)H oxidase activity was significantly increased in the HFD+vehicle compared with the ND+vehicle, and this increase was ameliorated in HFD+pioglitazone mice. Pioglitazone improved the exercise capacity in diabetic mice, which was due to the improvement in mitochondrial function and attenuation of oxidative stress in the SKM. Our data suggest that pioglitazone may be useful as an agent for the treatment of diabetes mellitus. Copyright © 2014 Elsevier B.V. All rights reserved.

Internet Program for Physical Activity and Exercise Capacity in Children With Juvenile Idiopathic Arthritis: A Multicenter Randomized Controlled Trial.

PubMed

Armbrust, Wineke; Bos, G J F Joyce; Wulffraat, Nico M; van Brussel, Marco; Cappon, Jeannette; Dijkstra, Pieter U; Geertzen, Jan H B; Legger, G Elizabeth; van Rossum, Marion A J; Sauer, Pieter J J; Lelieveld, Otto T H M

2017-07-01

To determine the effects of Rheumates@Work, an internet-based program supplemented with 4 group sessions, aimed at improving physical activity, exercise capacity, health-related quality of life (HRQoL), and participation in children with juvenile idiopathic arthritis. Patients were recruited from 3 pediatric rheumatology centers in The Netherlands for an observer-blinded, randomized controlled multicenter trial. Physical activity level, time spent in rest, light, and moderate-to-vigorous physical activity (MVPA) were recorded in a diary and with an accelerometer, before intervention, after intervention, and at followup after 3 and 12 months (intervention group only). Exercise capacity was assessed using the Bruce treadmill protocol, HRQoL was assessed with the Pediatric Quality of Life Inventory generic core scale, and participation in school and in physical education classes were assessed by questionnaire. The intervention group consisted of 28 children, and there were 21 children in the control group. MVPA , exercise capacity, and participating in school and physical education classes improved significantly in the intervention group. HRQoL improved in the control group. No significant differences were found between groups. The effect of Rheumates@Work on physical activity and exercise capacity lasted during the 12 months of followup. Improvements in physical activity were significantly better for the cohort starting in winter compared to the summer cohort. Rheumates@Work had a positive, albeit small, effect on physical activity, exercise capacity, and participation in school and physical education class in the intervention group. Improvements lasted for 12 months. Participants who started in winter showed the most improvement. Rheumates@Work had no effect on HRQoL. © 2016, American College of Rheumatology.

Relation of exercise capacity with lung volumes before and after 6-minute walk test in subjects with COPD.

PubMed

Wibmer, Thomas; Rüdiger, Stefan; Kropf-Sanchen, Cornelia; Stoiber, Kathrin M; Rottbauer, Wolfgang; Schumann, Christian

2014-11-01

There is growing evidence that exercise-induced variation in lung volumes is an important source of ventilatory limitation and is linked to exercise intolerance in COPD. The aim of this study was to compare the correlations of walk distance and lung volumes measured before and after a 6-min walk test (6MWT) in subjects with COPD. Forty-five subjects with stable COPD (mean pre-bronchodilator FEV1: 47 ± 18% predicted) underwent a 6MWT. Body plethysmography was performed immediately pre- and post-6MWT. Correlations were generally stronger between 6-min walk distance and post-6MWT lung volumes than between 6-min walk distance and pre-6MWT lung volumes, except for FEV1. These differences in Pearson correlation coefficients were significant for residual volume expressed as percent of total lung capacity (-0.67 vs -0.58, P = .043), percent of predicted residual volume expressed as percent of total lung capacity (-0.68 vs -0.59, P = .026), inspiratory vital capacity (0.65 vs 0.54, P = .019), percent of predicted inspiratory vital capacity (0.49 vs 0.38, P = .037), and percent of predicted functional residual capacity (-0.62 vs -0.47, P = .023). In subjects with stable COPD, lung volumes measured immediately after 6MWT are more closely related to exercise limitation than baseline lung volumes measured before 6MWT, except for FEV1. Therefore, pulmonary function testing immediately after exercise should be included in future studies on COPD for the assessment of exercise-induced ventilatory constraints to physical performance that cannot be adequately assessed from baseline pulmonary function testing at rest. Copyright © 2014 by Daedalus Enterprises.

Triphasic behavioral response of motor units to submaximal fatiguing exercise.

PubMed

Dorfman, L J; Howard, J E; McGill, K C

1990-07-01

We have measured the firing rate and amplitude of 4551 motor unit action potentials (MUAPs) recorded with concentric needle electrodes from the brachial biceps muscles of 10 healthy young adults before, during, and after 45 minutes of intermittent isometric exercise at 20% of maximum voluntary contraction (MVC), using an automatic method for decomposition of electromyographic activity (ADEMG). During and after exercise, MUAPs derived from contractions of 30% MVC showed progressive increase in mean firing rate (P less than or equal to .01) and amplitude (P less than or equal to .05). The firing rate increase preceded the rise in mean amplitude, and was evident prior to the development of fatigue, defined as reduction of MVC. Analysis of individual potentials revealed that the increase in firing rate and in amplitude reflected different MUAP subpopulations. A short-term (less than 1 minute) reduction in MUAP firing rates (P less than or equal to .05) was also observed at the onset of each test contraction. These findings suggest that motor units exhibit a triphasic behavioral response to prolonged submaximal exercise: (1) short-term decline and stabilization of onset firing rates, followed by (2) gradual and progressive increase in firing rates and firing variability, and then by (3) recruitment of additional (larger) motor units. The (2) and (3) components presumably compensate for loss of force-generating capacity in the exercising muscle, and give rise jointly to the well-known increase in total surface EMG which accompanies muscle fatigue.

Effects of obstructive sleep apnea and obesity on exercise function in children.

PubMed

Evans, Carla A; Selvadurai, Hiran; Baur, Louise A; Waters, Karen A

2014-06-01

Evaluate the relative contributions of weight status and obstructive sleep apnea (OSA) to cardiopulmonary exercise responses in children. Prospective, cross-sectional study. Participants underwent anthropometric measurements, overnight polysomnography, spirometry, cardiopulmonary exercise function testing on a cycle ergometer, and cardiac doppler imaging. OSA was defined as ≥ 1 obstructive apnea or hypopnea per hour of sleep (OAHI). The effect of OSA on exercise function was evaluated after the parameters were corrected for body mass index (BMI) z-scores. Similarly, the effect of obesity on exercise function was examined when the variables were adjusted for OAHI. Tertiary pediatric hospital. Healthy weight and obese children, aged 7-12 y. N/A. Seventy-one children were studied. In comparison with weight-matched children without OSA, children with OSA had a lower cardiac output, stroke volume index, heart rate, and oxygen consumption (VO2 peak) at peak exercise capacity. After adjusting for BMI z-score, children with OSA had 1.5 L/min (95% confidence interval -2.3 to -0.6 L/min; P = 0.001) lower cardiac output at peak exercise capacity, but minute ventilation and ventilatory responses to exercise were not affected. Obesity was only associated with physical deconditioning. Cardiac dysfunction was associated with the frequency of respiratory-related arousals, the severity of hypoxia, and heart rate during sleep. Children with OSA are exercise limited due to a reduced cardiac output and VO2 peak at peak exercise capacity, independent of their weight status. Comorbid OSA can further decrease exercise performance in obese children.

Effects of Exercise Training on Exercise Capacity in Pulmonary Arterial Hypertension: A Systematic Review of Clinical Trials.

PubMed

Babu, Abraham Samuel; Padmakumar, Ramachandran; Maiya, Arun G; Mohapatra, Aswini Kumar; Kamath, R L

2016-04-01

Pulmonary arterial hypertension (PAH) causes profound functional limitations and poor quality of life. Yet, there is only a limited literature available on the role of exercise training. This paper systematically reviews the effects of exercise training on exercise capacity in PAH. A systematic search of databases (PubMed, CINAHL, CENTRAL, Web of Science and PEDRo) was undertaken for English language articles published between 1(st) January 1980 and 31(st) March 2015. Quality rating for all articles was done using the Downs and Black scoring system. Fifteen articles of good (n=4), moderate (n=6) and poor (n=5) quality were included in the review. Exercise interventions included aerobic, resistance, inspiratory muscle training or a combination, for 6-18 weeks. Improvements were seen in exercise capacity (six minute walk distance (6MWD) and peak VO2) by 17-96m and 1.1-2.1ml/Kg/min, functional class by one class and quality of life, with minimal adverse events. There is evidence to recommend the use of exercise training as an adjunct to medical treatment in PAH. More clinical trials and research are required to assess the effects of different types of exercise programs in patients with PAH, while focussing on strong exercise endpoints to quantify the improvements seen with exercise training. Copyright © 2015 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.

Exercise Increases Markers of Spermatogenesis in Rats Selectively Bred for Low Running Capacity.

PubMed

Torma, Ferenc; Koltai, Erika; Nagy, Enikő; Ziaaldini, Mohammad Mosaferi; Posa, Aniko; Koch, Lauren G; Britton, Steven L; Boldogh, Istvan; Radak, Zsolt

2014-01-01

The oxidative stress effect of exercise training on testis function is under debate. In the present study we used a unique rat model system developed by artificial selection for low and high intrinsic running capacity (LCR and HCR, respectively) to evaluate the effects of exercise training on apoptosis and spermatogenesis in testis. Twenty-four 13-month-old male rats were assigned to four groups: control LCR (LCR-C), trained LCR (LCR-T), control HCR (HCR-C), and trained HCR (HCR-T). Ten key proteins connecting aerobic exercise capacity and general testes function were assessed, including those that are vital for mitochondrial biogenesis. The VO2 max of LCR-C group was about 30% lower than that of HCR-C rats, and the SIRT1 levels were also significantly lower than HCR-C. Twelve weeks of training significantly increased maximal oxygen consumption in LCR by nearly 40% whereas HCR remained unchanged. LCR-T had significantly higher levels of peroxisome proliferator-activated receptor-gamma coactivator-1 (PGC-1α), decreased levels of reactive oxygen species and increased acetylated p53 compared to LCR-C, while training produced no significant changes for these measures in HCR rats. BAX and Blc-2 were not different among all four groups. The levels of outer dense fibers -1 (Odf-1), a marker of spermatogenesis, increased in LCR-T rats, but decreased in HCR-TR rats. Moreover, exercise training increased the levels of lactate dehydrogenase C (LDHC) only in LCR rats. These data suggest that rats with low inborn exercise capacity can increase whole body oxygen consumption and running exercise capacity with endurance training and, in turn, increase spermatogenesis function via reduction in ROS and heightened activity of p53 in testes.

Variations in hemostatic parameters after near-maximum exercise and specific tests in athletes.

PubMed

Cerneca, F; Crocetti, G; Gombacci, A; Simeone, R; Tamaro, G; Mangiarotti, M A

1999-03-01

The clotting state of the blood changes according to the type of physical exercise to which a group of healthy subjects are subjected. We studied the behaviour of the coagulation system before and after near-maximum, specific and standardized exercise tests in three groups of males practising sports defined as demanding in terms of cardiovascular output. The study was a comparative investigation between athletes and the group of controls composed of presumably healthy males. athletes training for competitions such as marathon, rowing and weightlifting. we tested 7 rowers using the rowing machine, 12 marathon runners using the treadmill, 7 weightlifters using their own exercise equipment, and 7 healthy subjects (controls) using the cycle ergometer. during the tests we monitored heart rates, maximal oxygen intake, anaerobic threshold, respiratory quotient, maximum ventilation, and lactic acid. The following coagulation tests were performed before and after near-maximum exercise: prothrombin time (PT), partial activated thromboplastin time (PTT), fibrinogen (FBG), antithrombin III (ATIII), protein C (PC), protein S (PS), prothrombin fragment 1 + 2 (F1 + 2), tissue activator of plasminogen (t-PA) and its inhibitor (PAI). The most significant results showed a low basal PC in the rowers which decreased further after near-maximum exercise; significantly higher basal activities of ATIII, PC and PS in the marathon runners compared to the rowers; a high proportion of weightlifters showed a reduction in t-PA after exercise and an increase of PAI; the controls were the only group in which fibrinolytic activity and all the circulating anticoagulants increased after near-maximum exercise. Thus subjects who practise aerobic sports differ principally in terms of variations in inhibitors (low PC in rowers and marathon runners, increased presence of inhibitors in controls). The weightlifters did not show any significant variations, and so the kind of exercise involved (training to increase resistance and maximum strength) and the recovery times between the exercises do not seem to trigger changes in coagulation/fibrinolysis. We can therefore confirm that only relatively prolonged effort can trigger a mechanism beneficial to the cardiovascular system. In conclusion, physical activity benefits the coagulation system particularly as regards fibrinolysis, but certain subjects may be at risk of thrombosis and these must be identified and followed. We suggest that fibrinolytic activity be studied in athletes who practise weightlifting and have a history of cardiovascular disease, and that inhibitors (protein C in particular) be studied in rowers with a family history of thromboembolism.

Reduced haemodynamic coupling and exercise are associated with vascular stiffening in pulmonary arterial hypertension.

PubMed

Bellofiore, Alessandro; Dinges, Eric; Naeije, Robert; Mkrdichian, Hamorabi; Beussink-Nelson, Lauren; Bailey, Melissa; Cuttica, Michael J; Sweis, Ranya; Runo, James R; Keevil, Jon G; Francois, Christopher J; Shah, Sanjiv J; Chesler, Naomi C

2017-03-01

Inadequate right ventricular (RV) and pulmonary arterial (PA) functional responses to exercise are important yet poorly understood features of pulmonary arterial hypertension (PAH). This study combined invasive catheterisation with echocardiography to assess RV afterload, RV function and ventricular-vascular coupling in subjects with PAH. Twenty-six subjects with PAH were prospectively recruited to undergo right heart catheterisation and Doppler echocardiography at rest and during incremental exercise, and cardiac MRI at rest. Measurements at rest included basic haemodynamics, RV function and coupling efficiency (η). Measurements during incremental exercise included pulmonary vascular resistance (Z 0 ), characteristic impedance (Z C , a measure of proximal PA stiffness) and proximal and distal PA compliance (C PA ). In patients with PAH, the proximal PAs were significantly stiffer at maximum exercise (Z C =2.31±0.38 vs 1.33±0.15 WU×m 2 at rest; p=0.003) and PA compliance was decreased (C PA =0.88±0.10 vs 1.32±0.17 mL/mm Hg/m 2 at rest; p=0.0002). Z 0 did not change with exercise. As a result, the resistance-compliance (RC) time decreased with exercise (0.67±0.05 vs 1.00±0.07 s at rest; p<10 -6 ). When patients were grouped according to resting coupling efficiency, those with poorer η exhibited stiffer proximal PAs at rest, a lower maximum exercise level, and more limited C PA reduction at maximum exercise. In PAH, exercise causes proximal and distal PA stiffening, which combined with preserved Z 0 results in decreased RC time with exercise. Stiff PAs at rest may also contribute to poor haemodynamic coupling, reflecting reduced pulmonary vascular reserve that contributes to limit the maximum exercise level tolerated. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

[Insight into the training of patients with idiopathic inflammatory myopathy].

PubMed

Váncsa, Andrea

2016-09-01

Using current recommended treatment, a majority of patients with idiopathic inflammatory myopathy develop muscle impairment and poor health. Beneficial effects of exercise have been reported on muscle performance, aerobic capacity and health in chronic polymyositis and dermatomyositis, as well as in active disease and inclusion body myositis to some extent. Importantly, randomized controlled trials indicate that improved health and decreased clinical disease activity could be mediated through increased aerobic capacity. Recently, reports seeking pathomechanisms of the underlying effects of exercise on skeletal muscle indicate increased aerobic capacity (i.e. increased mitochondrial capacity and capillary density, reduced lactate levels), activation of genes of aerobic phenotype and muscle growth programs and down regulation of genes related to inflammation. Exercise contributes to both systemic and within-muscle adaptations demonstrating that it is fundamental for improving muscle performance and health in patients with idiopathic inflammatory myopathy. There is a need for randomized controlled trials to study the effects of exercise in patients with active disease and inclusion body myositis. Orv. Hetil., 2016, 157(39), 1557-1562.

Exercise recommendations for individuals with spinal cord injury.

PubMed

Jacobs, Patrick L; Nash, Mark S

2004-01-01

Persons with spinal cord injury (SCI) exhibit deficits in volitional motor control and sensation that limit not only the performance of daily tasks but also the overall activity level of these persons. This population has been characterised as extremely sedentary with an increased incidence of secondary complications including diabetes mellitus, hypertension and atherogenic lipid profiles. As the daily lifestyle of the average person with SCI is without adequate stress for conditioning purposes, structured exercise activities must be added to the regular schedule if the individual is to reduce the likelihood of secondary complications and/or to enhance their physical capacity. The acute exercise responses and the capacity for exercise conditioning are directly related to the level and completeness of the spinal lesion. Appropriate exercise testing and training of persons with SCI should be based on the individual's exercise capacity as determined by accurate assessment of the spinal lesion. The standard means of classification of SCI is by application of the International Standards for Classification of Spinal Cord Injury, written by the Neurological Standards Committee of the American Spinal Injury Association. Individuals with complete spinal injuries at or above the fourth thoracic level generally exhibit dramatically diminished cardiac acceleration with maximal heart rates less than 130 beats/min. The work capacity of these persons will be limited by reductions in cardiac output and circulation to the exercising musculature. Persons with complete spinal lesions below the T(10) level will generally display injuries to the lower motor neurons within the lower extremities and, therefore, will not retain the capacity for neuromuscular activation by means of electrical stimulation. Persons with paraplegia also exhibit reduced exercise capacity and increased heart rate responses (compared with the non-disabled), which have been associated with circulatory limitations within the paralysed tissues. The recommendations for endurance and strength training in persons with SCI do not vary dramatically from the advice offered to the general population. Systems of functional electrical stimulation activate muscular contractions within the paralysed muscles of some persons with SCI. Coordinated patterns of stimulation allows purposeful exercise movements including recumbent cycling, rowing and upright ambulation. Exercise activity in persons with SCI is not without risks, with increased risks related to systemic dysfunction following the spinal injury. These individuals may exhibit an autonomic dysreflexia, significantly reduced bone density below the spinal lesion, joint contractures and/or thermal dysregulation. Persons with SCI can benefit greatly by participation in exercise activities, but those benefits can be enhanced and the relative risks may be reduced with accurate classification of the spinal injury.

[Effects of aerobic exercise combined with resistance training on the cardiorespiratory fitness and exercise capacity of patients with stable coronary artery disease].

PubMed

Liu, S X; Chen, Y Y; Xie, K L; Zhang, W L

2017-12-24

Objective: To observe the effects of aerobic exercise combined with resistance training on the cardiorespiratory fitness and exercise capacity of patients with stable coronary artery disease (CAD) . Methods: From June 2014 to December 2015, 73 patients with stable CAD in our department were recruited and randomly assigned to two groups: the control group ( n= 38) and the exercise group ( n= 35) . Patients in both groups received conventional medical treatment for CAD and related cardiac health education. While for patients in exercise group, a twelve-week aerobic exercise combined with resistance training program were applied on top of conventional treatment and health education. Cardiorespiratory fitness and exercise capacity were evaluated by cardiopulmonary exercise testing. Results: (1) The exercise capacity was significantly increased in the exercise group after 12 weeks training as compared to baseline level: peak oxygen uptake per kilogram ( (26.25±5.14) ml·kg(-1)·min(-1) vs. (20.88±4.59) ml·kg(-1)·min(-1)) , anaerobic threshold ( (15.24±2.75) ml·kg(-1)·min(-1) vs. (13.52±2.92) ml·kg(-1)·min(-1)], peak oxygen pulse ( (11.91±2.89) ml/beat vs. (9.77±2.49) ml/beat) , peak Watts ( (113.2±34.0) W vs. (103.7±27.9) W) , peak metabolic equivalent ( (7.57±1.46) METs vs. (6.00±1.32) METs) (all P< 0.05 vs. baseline) . (2) The degree of improvement of peak oxygen uptake per kilogram ( (26.25±5.14) ml·kg(-1)·min(-1) vs. (22.32±4.00) ml·kg(-1)·min(-1)) , anaerobic threshold ( (15.24±2.75) ml·kg(-1)·min(-1) vs. (13.76±2.51) ml·kg(-1)·min(-1)) , peak oxygen pulse ( (11.91±2.89) ml/beat vs. (9.99±2.15) ml/beat) and peak metabolic equivalent ( (7.57±1.46) METs vs. (6.47±1.17) METs) were significantly higher in exercise group than in control group (all P< 0.05) . Conclusion: Aerobic training at an aerobic threshold level combined with Thera-band resistance training is safe for patients with stable coronary artery disease. This combined exercise program can significantly improve the cardiorespiratory fitness and exercise capacity of patients with stable coronary artery disease.

Dietary nitrate restores compensatory vasodilation and exercise capacity in response to a compromise in oxygen delivery in the noncompensator phenotype.

PubMed

Bentley, Robert F; Walsh, Jeremy J; Drouin, Patrick J; Velickovic, Aleksandra; Kitner, Sarah J; Fenuta, Alyssa M; Tschakovsky, Michael E

2017-09-01

Recently, dietary nitrate supplementation has been shown to improve exercise capacity in healthy individuals through a potential nitrate-nitrite-nitric oxide pathway. Nitric oxide has been shown to play an important role in compensatory vasodilation during exercise under hypoperfusion. Previously, we established that certain individuals lack a vasodilation response when perfusion pressure reductions compromise exercising muscle blood flow. Whether this lack of compensatory vasodilation in healthy, young individuals can be restored with dietary nitrate supplementation is unknown. Six healthy (21 ± 2 yr), recreationally active men completed a rhythmic forearm exercise. During steady-state exercise, the exercising arm was rapidly transitioned from an uncompromised (below heart) to a compromised (above heart) position, resulting in a reduction in local pressure of -31 ± 1 mmHg. Exercise was completed following 5 days of nitrate-rich (70 ml, 0.4 g nitrate) and nitrate-depleted (70 ml, ~0 g nitrate) beetroot juice consumption. Forearm blood flow (in milliliters per minute; brachial artery Doppler and echo ultrasound), mean arterial blood pressure (in millimeters of mercury; finger photoplethysmography), exercising forearm venous effluent (ante-cubital vein catheter), and plasma nitrite concentrations (chemiluminescence) revealed two distinct vasodilatory responses: nitrate supplementation increased (plasma nitrite) compared with placebo (245 ± 60 vs. 39 ± 9 nmol/l; P < 0.001), and compensatory vasodilation was present following nitrate supplementation (568 ± 117 vs. 714 ± 139 ml ⋅ min -1 ⋅ 100 mmHg -1 ; P = 0.005) but not in placebo (687 ± 166 vs. 697 ± 171 min -1 ⋅ 100 mmHg -1 ; P = 0.42). As such, peak exercise capacity was reduced to a lesser degree (-4 ± 39 vs. -39 ± 27 N; P = 0.01). In conclusion, dietary nitrate supplementation during a perfusion pressure challenge is an effective means of restoring exercise capacity and enabling compensatory vasodilation. NEW & NOTEWORTHY Previously, we identified young, healthy persons who suffer compromised exercise tolerance when exercising muscle perfusion pressure is reduced as a result of a lack of compensatory vasodilation. The ability of nitrate supplementation to restore compensatory vasodilation in such noncompensators is unknown. We demonstrated that beetroot juice supplementation led to compensatory vasodilation and restored perfusion and exercise capacity. Elevated plasma nitrite is an effective intervention for correcting the absence of compensatory vasodilation in the noncompensator phenotype. Copyright © 2017 the American Physiological Society.

Principles of exercise physiology: responses to acute exercise and long-term adaptations to training.

PubMed

Rivera-Brown, Anita M; Frontera, Walter R

2012-11-01

Physical activity and fitness are associated with a lower prevalence of chronic diseases, such as heart disease, cancer, high blood pressure, and diabetes. This review discusses the body's response to an acute bout of exercise and long-term physiological adaptations to exercise training with an emphasis on endurance exercise. An overview is provided of skeletal muscle actions, muscle fiber types, and the major metabolic pathways involved in energy production. The importance of adequate fluid intake during exercise sessions to prevent impairments induced by dehydration on endurance exercise, muscular power, and strength is discussed. Physiological adaptations that result from regular exercise training such as increases in cardiorespiratory capacity and strength are mentioned. The review emphasizes the cardiovascular and metabolic adaptations that lead to improvements in maximal oxygen capacity. Copyright © 2012 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

Mitochondrial coupling and capacity of oxidative phosphorylation in skeletal muscle of Inuit and Caucasians in the arctic winter.

PubMed

Gnaiger, E; Boushel, R; Søndergaard, H; Munch-Andersen, T; Damsgaard, R; Hagen, C; Díez-Sánchez, C; Ara, I; Wright-Paradis, C; Schrauwen, P; Hesselink, M; Calbet, J A L; Christiansen, M; Helge, J W; Saltin, B

2015-12-01

During evolution, mitochondrial DNA haplogroups of arctic populations may have been selected for lower coupling of mitochondrial respiration to ATP production in favor of higher heat production. We show that mitochondrial coupling in skeletal muscle of traditional and westernized Inuit habituating northern Greenland is identical to Danes of western Europe haplogroups. Biochemical coupling efficiency was preserved across variations in diet, muscle fiber type, and uncoupling protein-3 content. Mitochondrial phenotype displayed plasticity in relation to lifestyle and environment. Untrained Inuit and Danes had identical capacities to oxidize fat substrate in arm muscle, which increased in Danes during the 42 days of acclimation to exercise, approaching the higher level of the Inuit hunters. A common pattern emerges of mitochondrial acclimatization and evolutionary adaptation in humans at high latitude and high altitude where economy of locomotion may be optimized by preservation of biochemical coupling efficiency at modest mitochondrial density, when submaximum performance is uncoupled from VO2max and maximum capacities of oxidative phosphorylation. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Determination of Strength Exercise Intensities Based on the Load-Power-Velocity Relationship

PubMed Central

Jandačka, Daniel; Beremlijski, Petr

2011-01-01

The velocity of movement and applied load affect the production of mechanical power output and subsequently the extent of the adaptation stimulus in strength exercises. We do not know of any known function describing the relationship of power and velocity and load in the bench press exercise. The objective of the study is to find a function modeling of the relationship of relative velocity, relative load and mechanical power output for the bench press exercise and to determine the intensity zones of the exercise for specifically focused strength training of soccer players. Fifteen highly trained soccer players at the start of a competition period were studied. The subjects of study performed bench presses with the load of 0, 10, 30, 50, 70 and 90% of the predetermined one repetition maximum with maximum possible speed of movement. The mean measured power and velocity for each load (kg) were used to develop a multiple linear regression function which describes the quadratic relationship between the ratio of power (W) to maximum power (W) and the ratios of the load (kg) to one repetition maximum (kg) and the velocity (m•s−1) to maximal velocity (m•s−1). The quadratic function of two variables that modeled the searched relationship explained 74% of measured values in the acceleration phase and 75% of measured values from the entire extent of the positive power movement in the lift. The optimal load for reaching maximum power output suitable for the dynamics effort strength training was 40% of one repetition maximum, while the optimal mean velocity would be 75% of maximal velocity. Moreover, four zones: maximum power, maximum velocity, velocity-power and strength-power were determined on the basis of the regression function. PMID:23486484

Determination of strength exercise intensities based on the load-power-velocity relationship.

PubMed

Jandačka, Daniel; Beremlijski, Petr

2011-06-01

The velocity of movement and applied load affect the production of mechanical power output and subsequently the extent of the adaptation stimulus in strength exercises. We do not know of any known function describing the relationship of power and velocity and load in the bench press exercise. The objective of the study is to find a function modeling of the relationship of relative velocity, relative load and mechanical power output for the bench press exercise and to determine the intensity zones of the exercise for specifically focused strength training of soccer players. Fifteen highly trained soccer players at the start of a competition period were studied. The subjects of study performed bench presses with the load of 0, 10, 30, 50, 70 and 90% of the predetermined one repetition maximum with maximum possible speed of movement. The mean measured power and velocity for each load (kg) were used to develop a multiple linear regression function which describes the quadratic relationship between the ratio of power (W) to maximum power (W) and the ratios of the load (kg) to one repetition maximum (kg) and the velocity (m•s(-1)) to maximal velocity (m•s(-1)). The quadratic function of two variables that modeled the searched relationship explained 74% of measured values in the acceleration phase and 75% of measured values from the entire extent of the positive power movement in the lift. The optimal load for reaching maximum power output suitable for the dynamics effort strength training was 40% of one repetition maximum, while the optimal mean velocity would be 75% of maximal velocity. Moreover, four zones: maximum power, maximum velocity, velocity-power and strength-power were determined on the basis of the regression function.

The Benefits of Exercise Training on Aerobic Capacity in Patients with Heart Failure and Preserved Ejection Fraction.

PubMed

do Prado, Danilo Marcelo Leite; Rocco, Enéas Antônio

2017-01-01

Heart failure with preserved ejection fraction (HFpEF) is defined as an inability of the ventricles to optimally accept blood from atria with blunted end- diastolic volume response by limiting the stroke volume and cardiac output. The HEpEF prevalence is higher in elderly and women and may be associated to hypertension, diabetes mellitus and atrial fibrillation. Severe exercise intolerance, manifested by dyspnea and fatigue during physical effort is the important chronic symptom in HFpEF patients, in which is the major determinant of their reduced quality of life. In this sense, several studies demonstrated reduced aerobic capacity in terms of lower peak oxygen consumption (peak VO 2 ) in patients with HFpEF. In addition, the lower aerobic capacity observed in HFpEF may be due to impaired both convective and diffusive O 2 transport (i.e. reduced cardiac output and arteriovenous oxygen difference, respectively).Exercise training program can help restore physiological function in order to increase aerobic capacity and improve the quality of life in HFpEF patients. Therefore, the primary purpose of this chapter was to clarify the physiological mechanisms associated with reduced aerobic capacity in HFpEF patients. Secondly, special focus was devoted to show how aerobic exercise training can improve aerobic capacity and quality of life in HFpEF patients.

Exercise training in patients with heart disease: review of beneficial effects and clinical recommendations.

PubMed

Gielen, Stephan; Laughlin, M Harold; O'Conner, Christopher; Duncker, Dirk J

2015-01-01

Over the last decades exercise training has evolved into an established evidence-based therapeutic strategy with prognostic benefits in many cardiovascular diseases (CVDs): In stable coronary artery disease (CAD) exercise training attenuates disease progression by beneficially influencing CVD risk factors (i.e., hyperlipidemia, hypertension) and coronary endothelial function. In heart failure (HF) with reduced ejection fraction (HFrEF) training prevents the progressive loss of exercise capacity by antagonizing peripheral skeletal muscle wasting and by promoting left ventricular reverse remodeling with reduction in cardiomegaly and improvement of ejection fraction. Novel areas for exercise training interventions include HF with preserved ejection fraction (HFpEF), pulmonary hypertension, and valvular heart disease. In HFpEF, randomized studies indicate a lusitropic effect of training on left ventricular diastolic function associated with symptomatic improvement of exercise capacity. In pulmonary hypertension, reductions in pulmonary artery pressure were observed following endurance exercise training. Recently, innovative training methods such as high-intensity interval training, resistance training and others have been introduced. Although their prognostic value still needs to be determined, these approaches may achieve superior improvements in aerobic exercise capacity and gain in muscle mass, respectively. In this review, we give an overview of the prognostic and symptomatic benefits of exercise training in the most common cardiac disease entities. Additionally, key guideline recommendations for the initiation of training programs are summarized. Copyright © 2014 Elsevier Inc. All rights reserved.

Maintenance of exercise training benefits is associated with adequate milk and dairy products intake in elderly hypertensive subjects following detraining.

PubMed

Moraes, Wilson Max Almeida Monteiro de; Santos, Neucilane Silveira Dos; Aguiar, Larissa Pereira; Sousa, Luís Gustavo Oliveira de

2017-01-01

To investigate whether maintenance of exercise training benefits is associated with adequate milk and dairy products intake in hypertensive elderly subjects after detraining. Twenty-eight elderly hypertensive patients with optimal clinical treatment underwent 16 weeks of multicomponent exercise training program followed by 6 weeks of detraining, and were classified according to milk and dairy products intake as low milk (<3 servings) and high milk (≥3 servings) groups. After exercise training, there was a significant reduction (p<0.001) in body weight, systolic, diastolic and mean blood pressure, an increase in lower and upper limb strength (chair-stand test and elbow flexor test) as well as in aerobic capacity (stationary gait test) and functional capacity (sit down, stand up, and move around the house) in both groups. However, in the Low Milk Intake Group significant changes were observed: body weight (+0.5%), systolic, diastolic and mean blood pressure (+0.9%,+1.4% and +1.1%, respectively), lower extremity strength (-7.0%), aerobic capacity (-3.9%) and functional capacity (+5.4) after detraining. These parameters showed no significant differences between post-detraining and post-training period in High Milk Intake Group. Maintenance of exercise training benefits related to pressure levels, lower extremity strength and aerobic capacity, is associated with adequate milk and dairy products intake in hypertensive elderly subjects following 6 weeks of detraining.

Triiodothyronine, beta-adrenergic receptors, agonist responses, and exercise capacity.

PubMed

Martin, W H

1993-07-01

Although thyroid hormone excess results in increased beta-adrenergic receptor density or agonist responses in some cells of experimental animals, the role of these effects in contributing to clinical manifestations of hyperthyroidism in human subjects is unclear. To shed further light on this issue, we characterized the effect of 2 weeks of excess triiodothyronine administration on cardiac and metabolic responses to graded-dose isoproterenol infusion, skeletal muscle beta-adrenergic receptor density, and physiologic determinants of exercise capacity in young healthy subjects. The slope of the heart rate response to isoproterenol was 36% greater (p < 0.05) after triiodothyronine administration. In addition, beta-adrenergic receptor density was increased (p < 0.01) in all types of skeletal muscle fibers. Maximal oxygen uptake during treadmill exercise declined 5% (p < 0.001) after triiodothyronine administration because of a decrease in the arteriovenous oxygen difference (p < 0.05). The plasma lactate response to submaximal exercise was 25% greater (p < 0.01) in the hyperthyroid state. These effects were paralleled by a decrement in skeletal muscle oxidative capacity and a decrease in cross-sectional area of type 2A skeletal myocytes. Thus, thyroid hormone excess enhances cardiac beta-adrenergic sensitivity under in vivo conditions in human subjects. Nevertheless, exercise capacity is diminished in the hyperthyroid state, an effect that may be related to reduced skeletal muscle oxidative capacity and type 2A fiber atrophy.

A comparison of echocardiographic variables of right ventricular function with exercise capacity after bosentan treatment in patients with pulmonary arterial hypertension: Results from a multicenter, prospective, cohort study.

PubMed

Kim, Hyungseop; Bae Lee, Jin; Park, Jae-Hyeong; Yoo, Byung-Su; Son, Jang-Won; Yang, Dong Heon; Lee, Bong-Ryeol

2017-01-01

Bosentan reduces pulmonary arterial pressure and improves exercise capacity in patients with pulmonary arterial hypertension (PAH). However, there are limited data regarding the extent to which the changes in echocardiographic variables reflect improvements in exercise capacity. We aimed to assess the improvement of echocardiographic variables and exercise capacity after 6 months of bosentan treatment for PAH. We performed a prospective study from June 2012 to June 2015 in seven participating medical centers. Echocardiography, including tissue Doppler imaging (TDI) and the 6-minute walk test distance (6MWD), was performed at baseline and after 6 months of bosentan treatment. We analyzed 19 patients with PAH: seven with congenital shunt, six with collagen vascular disease, and six with idiopathic PAH. After bosentan treatment, mean 6MWD increased by 50 meters. Right ventricle (RV) systolic pressure, tricuspid annular plane systolic excursion, myocardial performance index (MPI) derived from TDI (MPI-TDI) of RV and left ventricle (LV), RV fractional area change, and RV ejection fraction were significantly improved. In particular, the magnitude of RV and LV MPI-TDI showed good correlation with changes in the 6MWD. The magnitude of RV and LV MPI-TDI was strongly associated with improvements in exercise capacity. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 45:28-34, 2017. © 2016 Wiley Periodicals, Inc.

Dietary nitrate supplementation in COPD: an acute, double-blind, randomized, placebo-controlled, crossover trial.

PubMed

Kerley, Conor P; Cahill, Kathleen; Bolger, Kenneth; McGowan, Aisling; Burke, Conor; Faul, John; Cormican, Liam

2015-01-30

The acute consumption of dietary nitrate has been shown to improve exercise capacity in athletes, healthy adults and subjects with peripheral vascular disease. Many COPD patients have reduced exercise capacity. We hypothesized that acute nitrate consumption might increase incremental shuttle walk test (ISWT) distance in COPD subjects. Eleven COPD subjects were randomly assigned to consume either a high nitrate or a matched, low nitrate beverage in a double-blind, randomized, placebo-controlled, crossover design. ISWT distance was measured both before and 3 h after the beverage and change was recorded. After a 7-day washout, ISWT distances were re-measured before and 3 h after the alternate beverage and changes were recorded. We observed an increase in ISWT distance after consuming the high nitrate juice (25 m) compared with a reduction after the low nitrate juice (14 m) (p < 0.01). This improvement in exercise capacity was associated with significant increases in serum nitrate (p < 0.000005) and nitrite (p < 0.01) levels and a significant lowering of resting blood pressure (<0.05). In patients with stable COPD, the acute consumption of dietary nitrate increased serum nitrate/nitrite levels and exercise capacity and was associated with a decrease in resting blood pressure. Nitrate consumption might alter exercise capacity in COPD patients. Copyright © 2014 Elsevier Inc. All rights reserved.

Exercise Capacity Assessment by the Modified Shuttle Walk Test and its Correlation with Biochemical Parameters in Obese Children and Adolescents.

PubMed

de Assumpção, Priscila Kurz; Heinzmann-Filho, João Paulo; Isaia, Heloisa Ataíde; Holzschuh, Flávia; Dalcul, Tiéle; Donadio, Márcio Vinícius Fagundes

2018-03-23

To evaluate exercise capacity of obese children and adolescents compared with normal-weight individuals and to investigate possible correlations with blood biochemical parameters. In this study, children and adolescents between 6 and 18 y were included and divided into control (eutrophic) and obese groups according to body mass index (BMI). Data were collected regarding demographic, anthropometric, waist circumference and exercise capacity through the Modified Shuttle Walk Test (MSWT). In the obese group, biochemical parameters in the blood (total cholesterol, HDL, LDL, triglycerides and glucose) were evaluated, and a physical activity questionnaire was applied. Seventy seven participants were included; 27 in the control group and 50 obese. There was no significant difference between the two groups regarding sample characteristics, except for body weight, BMI and waist circumference. Most obese children presented results of biochemical tests within the desirable limit, though none were considered active. There was a significant exercise capacity reduction (p < 0.001) in the obese group compared to control subjects. Positive correlations were identified for the MSWT with age and height, and a negative correlation with BMI. However, there were no correlations with the biochemical parameters analyzed. Obese children and adolescents have reduced exercise capacity when compared to normal individuals. The MSWT performance seems to have a negative association with BMI, but is not correlated with blood biochemical parameters.

Rising temperatures may drive fishing-induced selection of low-performance phenotypes

PubMed Central

Clark, Timothy D.; Messmer, Vanessa; Tobin, Andrew J.; Hoey, Andrew S.; Pratchett, Morgan S.

2017-01-01

Climate warming is likely to interact with other stressors to challenge the physiological capacities and survival of phenotypes within populations. This may be especially true for the billions of fishes per year that undergo vigorous exercise prior to escaping or being intentionally released from fishing gear. Using adult coral grouper (Plectropomus leopardus), an important fisheries species throughout the Indo-Pacific, we show that population-level survival following vigorous exercise is increasingly compromised as temperatures increase from current-day levels (100–67% survival at 24–30 °C) to those projected for the end of the century (42% survival at 33 °C). Intriguingly, we demonstrate that high-performance individuals take longer to recover to a resting metabolic state and subsequently have lower survival in warm water compared with conspecifics that exercise less vigorously. Moreover, we show that post-exercise mortality of high-performance phenotypes manifests after 3–13 d at the current summer maximum (30 °C), while mortality at 33 °C occurs within 1.8–14.9 h. We propose that wild populations in a warming climate may become skewed towards low-performance phenotypes with ramifications for predator-prey interactions and community dynamics. Our findings highlight the susceptibility of phenotypic diversity to fishing activities and demonstrate a mechanism that may contribute to fishing-induced evolution in the face of ongoing climate change. PMID:28094310

In healthy elderly postmenopausal women variations in BMD and BMC at various skeletal sites are associated with differences in weight and lean body mass rather than by variations in habitual physical activity, strength or VO2max.

PubMed

Schöffl, I; Kemmler, W; Kladny, B; Vonstengel, S; Kalender, W A; Engelke, K

2008-01-01

The objective of this study was an integrated cross-sectional investigation for answering the question whether differences in bone mineral density in elderly postmenopausal women are associated with differences in habitual physical activity and unspecific exercise levels. Two hundred and ninety nine elderly women (69-/+3 years), without diseases or medication affecting bone metabolism were investigated. The influence of weight, body composition and physical activity on BMD was measured at multiple sites using different techniques (DXA, QCT, and QUS). Physical activity and exercise level were assessed by questionnaire, maximum strength of the legs and aerobic capacity. Variations in physical activity or habitual exercise had no effect on bone. The only significant univariate relation between strength/VO(2)max and BMD/BMC that remained after adjusting for confounding variables was between arm BMD (DXA) and hand-grip strength. The most important variable for explaining BMD was weight and for cortical BMC of the femur (QCT) lean body mass. Weight and lean body mass emerge as predominant predictors of BMD in normal elderly women, whereas the isolated effect of habitual physical activity, unspecific exercise participation, and muscle strength on bone parameters is negligible. Thus, an increase in the amount of habitual physical activity will probably have no beneficial impact on bone.

Effect of sodium bicarbonate on prolonged running performance: A randomized, double-blind, cross-over study.

PubMed

Freis, Tanja; Hecksteden, Anne; Such, Ulf; Meyer, Tim

2017-01-01

The ability to sustain intense exercise seems to be partially limited by the body's capability to counteract decreases in both intra- and extracellular pH. While the influence of an enhanced buffering capacity via sodium bicarbonate (BICA) on short-term, high-intensity exercise performance has been repeatedly investigated, studies on prolonged endurance performances are comparatively rare, especially for running. The aim of the following study was to assess the ergogenic effects of an oral BICA substitution upon exhaustive intensive endurance running performance. In a double-blind randomized cross-over study, 18 trained runners (VO2peak: 61.2 ± 6.4 ml•min-1•kg-1) performed two exhaustive graded exercise tests and two constant load tests (30 main at 95% individual anaerobic threshold (IAT) followed by 110% IAT until exhaustion) after ingestion of either sodium bicarbonate (BICA) (0.3 g/kg) or placebo (4 g NaCl) diluted in 700 ml of water. Time to exhaustion (TTE) in the constant load test was defined as the main outcome measure. Throughout each test respiratory gas exchange measurements were conducted as well as determinations of heart rate, blood gases and blood lactate concentration. TTE in the constant load test did not differ significantly between BICA and placebo conditions (BICA: 39.6 ± 5.6 min, placebo: 39.3 ± 5.6 min; p = 0.78). While pH in the placebo test dropped to a slightly acidotic value two minutes after cessation of exercise (7.34 ± 0.05) the value in the BICA trial remained within the normal range (7.41 ± 0.06) (p < 0.001). In contrast, maximum running speed (Vmax) in the exhaustive graded exercise test was significantly higher with BICA (17.4 ± 1.0 km/h) compared to placebo (17.1 ± 1.0 km/h) (p = 0.009). The numerical difference in maximum oxygen consumption (VO2peak) failed to reach statistical significance (BICA: 61.2 ± 6.4 ml•min-1•kg-1, placebo: 59.8 ± 6.4 ml•min-1•kg-1; p = 0.31). Maximum blood lactate was significantly higher with BICA compared to the corresponding placebo test (BICA: 11.1 ± 2.3 mmol/l, placebo: 8.9 ± 3.0 mmol/l; p < 0.001). At the end of exercise, an acidotic pH value was found in both exhaustive graded exercise tests (p = 0.002). BICA caused gastrointestinal side effects in 15 patients. Maximal performance was enhanced significantly after BICA administration. The ergogenic effect of BICA in the exhaustive graded exercise test can most likely be attributed to an increased anaerobic glycolysis that is reflected by an accumulation of lactate. However, TTE in prolonged high-intensity running was not improved. Even at the end of exercise no severe metabolic acidosis was found. Metabolic acidification as one of the dominant factors causing muscular fatigue should therefore be reconsidered. German Clinical Trials Register (DRKS) DRKS00011284.

Importance of Non-invasive Right and Left Ventricular Variables on Exercise Capacity in Patients with Tetralogy of Fallot Hemodynamics.

PubMed

Meierhofer, Christian; Tavakkoli, Timon; Kühn, Andreas; Ulm, Kurt; Hager, Alfred; Müller, Jan; Martinoff, Stefan; Ewert, Peter; Stern, Heiko

2017-12-01

Good quality of life correlates with a good exercise capacity in daily life in patients with tetralogy of Fallot (ToF). Patients after correction of ToF usually develop residual defects such as pulmonary regurgitation or stenosis of variable severity. However, the importance of different hemodynamic parameters and their impact on exercise capacity is unclear. We investigated several hemodynamic parameters measured by cardiovascular magnetic resonance (CMR) and echocardiography and evaluated which parameter has the most pronounced effect on maximal exercise capacity determined by cardiopulmonary exercise testing (CPET). 132 patients with ToF-like hemodynamics were tested during routine follow-up with CMR, echocardiography and CPET. Right and left ventricular volume data, ventricular ejection fraction and pulmonary regurgitation were evaluated by CMR. Echocardiographic pressure gradients in the right ventricular outflow tract and through the tricuspid valve were measured. All data were classified and correlated with the results of CPET evaluations of these patients. The analysis was performed using the Random Forest model. In this way, we calculated the importance of the different hemodynamic variables related to the maximal oxygen uptake in CPET (VO 2 %predicted). Right ventricular pressure showed the most important influence on maximal oxygen uptake, whereas pulmonary regurgitation and right ventricular enddiastolic volume were not important hemodynamic variables to predict maximal oxygen uptake in CPET. Maximal exercise capacity was only very weakly influenced by right ventricular enddiastolic volume and not at all by pulmonary regurgitation in patients with ToF. The variable with the most pronounced influence was the right ventricular pressure.

The Link between Reduced Inspiratory Capacity and Exercise Intolerance in Chronic Obstructive Pulmonary Disease.

PubMed

O'Donnell, Denis E; Elbehairy, Amany F; Webb, Katherine A; Neder, J Alberto

2017-07-01

Low inspiratory capacity (IC), chronic dyspnea, and reduced exercise capacity are inextricably linked and are independent predictors of increased mortality in chronic obstructive pulmonary disease. It is no surprise, therefore, that a major goal of management is to improve IC by reducing lung hyperinflation to improve respiratory symptoms and health-related quality of life. The negative effects of lung hyperinflation on respiratory muscle and cardiocirculatory function during exercise are now well established. Moreover, there is growing appreciation that a key mechanism of exertional dyspnea in chronic obstructive pulmonary disease is critical mechanical constraints on tidal volume expansion during exercise when resting IC is reduced. Further evidence for the importance of lung hyperinflation comes from multiple studies, which have reported the clinical benefits of therapeutic interventions that reduce lung hyperinflation and increase IC. A reduced IC in obstructive pulmonary disease is further eroded by exercise and contributes to ventilatory limitation and dyspnea. It is an important outcome for both clinical and research studies.

Enzymatic capacities of skeletal muscle - Effects of different types of training

NASA Technical Reports Server (NTRS)

Booth, F. W.; Hugman, G. R.

1981-01-01

Long-term adaptation mechanisms to maintain homeostasis at increased levels of exertion such as those caused by regular exercise are described. Mitochondrial changes have been found to be a result of endurance exercises, while mitochondrial responses to other types of exercise are small. Further discussion is devoted to long-term changes in glucose transport, hexokinase, phosphofructokinase, pyruvate kinase, and the increased sensitivity of an endurance trained muscle to insulin. Less lactate has been found to be produced by the skeletal muscles at the same work rate after adaptation to endurance exercise training, and the capacity for the flux of the two-carbon acetyl chain through the citric acid cycle increases in skeletal muscles in response to endurance training. Finally, endurance training is noted to result in glycogen sparing and an increase in the capacity to utilize fatty acids.

Relation between lung function, exercise capacity, and exposure to asbestos cement.

PubMed Central

Wollmer, P; Eriksson, L; Jonson, B; Jakobsson, K; Albin, M; Skerfving, S; Welinder, H

1987-01-01

A group of 137 male workers with known exposure (mean 20 fibre years per millilitre) to asbestos cement who had symptoms or signs of pulmonary disease was studied together with a reference group of 49 healthy industrial workers with no exposure to asbestos. Lung function measurements were made at rest and during exercise. Evidence of lung fibrosis was found as well as of obstructive airways disease in the exposed group compared with the reference group. Asbestos cement exposure was related to variables reflecting lung fibrosis but not to variables reflecting airflow obstruction. Smoking was related to variables reflecting obstructive lung disease. Exercise capacity was reduced in the exposed workers and was related to smoking and to lung function variables, reflecting obstructive airways disease. There was no significant correlation between exercise capacity and exposure to asbestos cement. PMID:3651353

Black tea high-molecular-weight polyphenol stimulates exercise training-induced improvement of endurance capacity in mouse via the link between AMPK and GLUT4.

PubMed

Eguchi, Tomoaki; Kumagai, Chiaki; Fujihara, Takashi; Takemasa, Thoru; Ozawa, Tetsuo; Numata, Osamu

2013-01-01

Aerobic exercise can promote "fast-to-slow transition" in skeletal muscles, i.e. an increase in oxidative fibers, mitochondria, and myoglobin and improvement in glucose and lipid metabolism. Here, we found that mice administered Mitochondria Activation Factor (MAF) combined with exercise training could run longer distances and for a longer time compared with the exercise only group; MAF is a high-molecular-weight polyphenol purified from black tea. Furthermore, MAF intake combined with exercise training increased phosphorylation of AMPK and mRNA level of glucose transporter 4 (GLUT4). Thus, our data demonstrate for the first time that MAF activates exercise training-induced intracellular signaling pathways that involve AMPK, and improves endurance capacity.

The measurement of energy consumption by exercise bikes

NASA Astrophysics Data System (ADS)

Jwo, Ching-Song; Chien, Chao-Chun; Jeng, Lung-Yue

2006-11-01

This paper is intended as an investigation is that to measure the amount of energy consumption can be consumed by riding bikes and also could recycle the consuming energy during exercising. Exercisers ride the bicycle inputting the driving force through a compressor of refrigeration system, which can circulate the refrigerant in the system and calculate the calorific capacity from the spread of the condenser. In addition, we can make up chiller water in the evaporator. Experiments were performed to prove the hypotheses. Therefore, this experiment has designed the sports goods which reach the purpose of doing exercise, measuring accurately the consuming calorific capacity and having the function of making chiller water. After exercising, you can drink the water producing during exercise and apply on the system of air conditioner, which attains two objectives.

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.

Impact of a brief exercise program on the physical and psychosocial health of prostate cancer survivors: A pilot study.

PubMed

Skinner, Tina L; Peeters, Gmme Geeske; Croci, Ilaria; Bell, Katherine R; Burton, Nicola W; Chambers, Suzanne K; Bolam, Kate A

2016-09-01

It is well established that exercise is beneficial for prostate cancer survivors. The challenge for health professionals is to create effective strategies to encourage survivors to exercise in the community. Many community exercise programs are brief in duration (e.g. <5 exercise sessions); whilst evidence for the efficacy of exercise within the literature are derived from exercise programs ≥8 weeks in duration, it is unknown if health benefits can be obtained from a shorter program. This study examined the effect of a four-session individualized and supervised exercise program on the physical and psychosocial health of prostate cancer survivors. Fifty-one prostate cancer survivors (mean age 69±7 years) were prescribed 1 h, individualized, supervised exercise sessions once weekly for 4 weeks. Participants were encouraged to increase their physical activity levels outside of the exercise sessions. Objective measures of muscular strength, exercise capacity, physical function and flexibility; and self-reported general, disease-specific and psychosocial health were assessed at baseline and following the intervention. Improvements were observed in muscle strength (leg press 17.6 percent; P < 0.001), exercise capacity (400-m walk 9.3 percent; P < 0.001), physical function (repeated chair stands 20.1 percent, usual gait speed 19.3 percent, timed up-and-go 15.0 percent; P < 0.001), flexibility (chair sit and reach +2.9 cm; P < 0.001) and positive well-being (P = 0.014) following the exercise program. A four-session exercise program significantly improved the muscular strength, exercise capacity, physical function and positive well-being of prostate cancer survivors. This short-duration exercise program is safe and feasible for prostate cancer survivors and a randomized controlled trial is now required to determine whether a similar individualized exercise regimen improves physical health and mental well-being over the short, medium and long term. © 2016 John Wiley & Sons Australia, Ltd.

Self-Paced Exercise, Affective Response, and Exercise Adherence: A Preliminary Investigation Using Ecological Momentary Assessment.

PubMed

Williams, David M; Dunsiger, Shira; Emerson, Jessica A; Gwaltney, Chad J; Monti, Peter M; Miranda, Robert

2016-06-01

Affective response to exercise may mediate the effects of self-paced exercise on exercise adherence. Fiftynine low-active (exercise <60 min/week), overweight (body mass index: 25.0-39.9) adults (ages 18-65) were randomly assigned to self-paced (but not to exceed 76% maximum heart rate) or prescribed moderate intensity exercise (64-76% maximum heart rate) in the context of otherwise identical 6-month print-based exercise promotion programs. Frequency and duration of exercise sessions and affective responses (good/bad) to exercise were assessed via ecological momentary assessment throughout the 6-month program. A regression-based mediation model was used to estimate (a) effects of experimental condition on affective response to exercise (path a = 0.20, SE = 0.28, f 2 = 0.02); (b) effects of affective response on duration/latency of the next exercise session (path b = 0.47, SE = 0.25, f 2 = 0.04); and (c) indirect effects of experimental condition on exercise outcomes via affective response (path ab = 0.11, SE = 0.06, f 2 = 0.10). Results provide modest preliminary support for a mediational pathway linking self-paced exercise, affective response, and exercise adherence.

[Results of a physical therapy program in nursing home residents: A randomized clinical trial].

PubMed

Casilda-López, Jesús; Torres-Sánchez, Irene; Garzón-Moreno, Victor Manuel; Cabrera-Martos, Irene; Valenza, Marie Carmen

2015-01-01

The maintenance of the physical functionality is a key factor in the care of the elderly. Inactive people have a higher risk of death due to diseases associated with inactivity. In addition, the maintenance of optimal levels of physical and mental activity has been suggested as a protective factor against the development and progression of chronic illnesses and disability. The objective of this study is to assess the effectiveness of an 8-week exercise program with elastic bands, on exercise capacity, walking and balance in nursing home residents. A nursing home sample was divided into two groups, intervention group (n=26) and control group (n=25). The intervention group was included in an 8-week physical activity program using elastic bands, twice a week, while the control group was took part in a walking programme. Outcome measurements were descriptive variables (anthropometric characteristics, quality of life, fatigue, fear of movement) and fundamental variables (exercise capacity, walking and balance). A significant improvement in balance and walking speed was observed after the programme. Additionally, exercise capacity improved significantly (P≤.001), and the patients showed an improvement in perceived dyspnea after the physical activity programme in the intervention group. The exercise program was safe and effective in improving dyspnea, exercise capacity, walking, and balance in elderly. Copyright © 2014 SEGG. Published by Elsevier Espana. All rights reserved.

Low-level carbon monoxide exposure and work capacity at 1600 meters

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weiser, P.C.; Cropp, G.J.A.; Morrill, C.G.

At sea level, low-level carbon monoxide (CO) exposure impairs exercise performance. To determine if altitude residence at 1600 m augments this CO effect, two studies of graded treadmill work capacity were done. The Initial Study investigated nine, non-smoking male subjects breathing either filtered air (FA) or 28 ppm CO in filtered air. End-exercise carboxyhemoglobin (HbCO) levels averaged 0.9 %HbCO breathing FA and 4.7 %HbCO breathing CO. Total work performance and aerobic work capacity were reduced. Work heart rate was elevated, and post-exercise left ventricular ejection time breathing CO did not shorten to the same degree as with FA exposure. COmore » exposure resulted in a lower anaerobic threshold, and a greater minute ventilation occurred at work rates heavier than the anaerobic threshold due to an increased blood lactate level. The Dose-Response Study exposed twelve subjects to FA or CO such that the end-exercise HbCO levels were 0.7, 3.5, 5.4 and 8.7 %HbCO. Exercise performance and aerobic work capacity were impaired in proportion to the CO exposure. In both studies, maximal cardio-pulmonary responses were not different, but submaximal exercise changes were elevated breathing CO. Thus, in healthy young men residing near 1600 m, an increase in low-level CO exposure produced a linear decrement in maximal aerobic performance similar to that reported at sea level.« less

Intrinsic aerobic capacity sets a divide for aging and longevity

PubMed Central

Koch, Lauren Gerard; Kemi, Ole J.; Qi, Nathan; Leng, Sean X.; Bijma, Piter; Gilligan, Lori J.; Wilkinson, John E.; Wisløff, Helene; Høydal, Morten A.; Rolim, Natale; Abadir, Peter M.; Van Grevenhof, Ilse; Smith, Godfrey L.; Burant, Charles F.; Ellingsen, Øyvind; Britton, Steven L.; Wisløff, Ulrik

2011-01-01

Rationale Low aerobic exercise capacity is a powerful predictor of premature morbidity and mortality for healthy adults as well as those with cardiovascular disease For aged populations, poor performance on treadmill or extended walking tests indicates closer proximity to future health declines. Together, these findings suggest a fundamental connection between aerobic capacity and longevity. Objectives Through artificial selective breeding, we developed an animal model system to prospectively test the association between aerobic exercise capacity and survivability (aerobic hypothesis). Methods and Results Laboratory rats of widely diverse genetic backgrounds (N:NIH stock) were selectively bred for low or high intrinsic (inborn) treadmill running capacity. Cohorts of male and female rats from generations 14, 15 and 17 of selection were followed for survivability and assessed for age-related declines in cardiovascular fitness including maximal oxygen uptake (VO2max), myocardial function, endurance performance, and change in body mass. Median lifespan for low exercise capacity rats was 28-45% shorter than high capacity rats (hazard ratio, 0.06; P<.001). VO2max, measured across adulthood was a reliable predictor of lifespan (P<.001). During progression from adult to old age, left ventricular myocardial and cardiomyocyte morphology, contractility, and intracellular Ca2+ handling in both systole and diastole, as well as mean blood pressure, were more compromised in rats bred for low aerobic capacity. Physical activity levels, energy expenditure (VO2), and lean body mass were all better sustained with age in rats bred for high aerobic capacity. Conclusions These data obtained from a contrasting heterogeneous model system provide strong evidence that genetic segregation for aerobic exercise capacity can be linked with longevity and useful for deeper mechanistic exploration. PMID:21921265

Intrinsic aerobic capacity sets a divide for aging and longevity.

PubMed

Koch, Lauren Gerard; Kemi, Ole J; Qi, Nathan; Leng, Sean X; Bijma, Piter; Gilligan, Lori J; Wilkinson, John E; Wisløff, Helene; Høydal, Morten A; Rolim, Natale; Abadir, Peter M; van Grevenhof, Elizabeth M; Smith, Godfrey L; Burant, Charles F; Ellingsen, Oyvind; Britton, Steven L; Wisløff, Ulrik

2011-10-28

Low aerobic exercise capacity is a powerful predictor of premature morbidity and mortality for healthy adults as well as those with cardiovascular disease. For aged populations, poor performance on treadmill or extended walking tests indicates closer proximity to future health declines. Together, these findings suggest a fundamental connection between aerobic capacity and longevity. Through artificial selective breeding, we developed an animal model system to prospectively test the association between aerobic exercise capacity and survivability (aerobic hypothesis). Laboratory rats of widely diverse genetic backgrounds (N:NIH stock) were selectively bred for low or high intrinsic (inborn) treadmill running capacity. Cohorts of male and female rats from generations 14, 15, and 17 of selection were followed for survivability and assessed for age-related declines in cardiovascular fitness including maximal oxygen uptake (VO(2max)), myocardial function, endurance performance, and change in body mass. Median lifespan for low exercise capacity rats was 28% to 45% shorter than high capacity rats (hazard ratio, 0.06; P<0.001). VO(2max), measured across adulthood was a reliable predictor of lifespan (P<0.001). During progression from adult to old age, left ventricular myocardial and cardiomyocyte morphology, contractility, and intracellular Ca(2+) handling in both systole and diastole, as well as mean blood pressure, were more compromised in rats bred for low aerobic capacity. Physical activity levels, energy expenditure (Vo(2)), and lean body mass were all better sustained with age in rats bred for high aerobic capacity. These data obtained from a contrasting heterogeneous model system provide strong evidence that genetic segregation for aerobic exercise capacity can be linked with longevity and are useful for deeper mechanistic exploration of aging.

Controlled-frequency breath swimming improves swimming performance and running economy.

PubMed

Lavin, K M; Guenette, J A; Smoliga, J M; Zavorsky, G S

2015-02-01

Respiratory muscle fatigue can negatively impact athletic performance, but swimming has beneficial effects on the respiratory system and may reduce susceptibility to fatigue. Limiting breath frequency during swimming further stresses the respiratory system through hypercapnia and mechanical loading and may lead to appreciable improvements in respiratory muscle strength. This study assessed the effects of controlled-frequency breath (CFB) swimming on pulmonary function. Eighteen subjects (10 men), average (standard deviation) age 25 (6) years, body mass index 24.4 (3.7) kg/m(2), underwent baseline testing to assess pulmonary function, running economy, aerobic capacity, and swimming performance. Subjects were then randomized to either CFB or stroke-matched (SM) condition. Subjects completed 12 training sessions, in which CFB subjects took two breaths per length and SM subjects took seven. Post-training, maximum expiratory pressure improved by 11% (15) for all 18 subjects (P < 0.05) while maximum inspiratory pressure was unchanged. Running economy improved by 6 (9)% in CFB following training (P < 0.05). Forced vital capacity increased by 4% (4) in SM (P < 0.05) and was unchanged in CFB. These findings suggest that limiting breath frequency during swimming may improve muscular oxygen utilization during terrestrial exercise in novice swimmers. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Cardiopulmonary fitness in a sample of Malaysian population.

PubMed

Singh, R; Singh, H J; Sirisinghe, R G

1989-01-01

Lung capacity and maximum oxygen uptake (VO2max) were measured directly in 167 healthy males, from all the main races in Malaysia. Their ages ranged from 13 to 59 years. They were divided into five age groups (A to E), ranging from the second to the sixth decade. Lung capacities were determined using a dry spirometer and VO2max was taken as the maximum rate of oxygen consumption during exhaustive exercise on a cycle ergometer. Mean forced vital capacity (FVC) was 3.3 +/- 0.5 l and it correlated negatively with age. Mean VO2max was 3.2 +/- 0.2 l.min-1 (56.8 +/- 3.5 ml.kg-1.min-1) in Group A (13-19 years) compared to 1.7 +/- 0.2 l.min-1 (28.9 +/- 2.9 ml.kg-1.min-1) in Group E (50-59 years). Regression analysis revealed an age-related decline in VO2max of 0.77 ml.kg-1.min-1.year-1. Multiple regression of the data gave the following equations for the prediction of an individual's VO2max: VO2max (l.min-1) = 1.99 + 0.035 (weight)-0.04 (age), VO2max (ml.kg-1.min-1) = 67.7-0.77 (age), where age is in years, weight in kg. In terms of VO2max as an index of cardiopulmonary performance. Malaysians have a relatively lower capacity when related to the Swedish norms or even to those of some Chilean workers. Malaysians were, however, within the average norms of the American Heart Association's recommendations. Age-related decline in VO2max was also somewhat higher in the Malaysians.

Acute exhaustive rowing exercise reduces skin microvascular dilator function in young adult rowing athletes.

PubMed

Stupin, Marko; Stupin, Ana; Rasic, Lidija; Cosic, Anita; Kolar, Luka; Seric, Vatroslav; Lenasi, Helena; Izakovic, Kresimir; Drenjancevic, Ines

2018-02-01

The effect of acute exhaustive exercise session on skin microvascular reactivity was assessed in professional rowers and sedentary subjects. A potential involvement of altered hemodynamic parameters and/or oxidative stress level in the regulation of skin microvascular blood flow by acute exercise were determined. Anthropometric, biochemical, and hemodynamic parameters were measured in 18 young healthy sedentary men and 20 professional rowers who underwent a single acute exercise session. Post-occlusive reactive hyperemia (PORH), endothelium-dependent acetylcholine (ACh), and endothelium-independent sodium nitroprusside (SNP) microvascular responses were assessed by laser Doppler flowmetry in skin microcirculation before and after acute exercise. Serum lipid peroxidation products and plasma antioxidant capacity were measured using spectrophotometry. At baseline, rowers had significantly lower diastolic blood pressure (DBP) and heart rate (HR), and higher stroke volume (SV), PORH, and endothelium-dependent vasodilation than sedentary. Acute exercise caused a significant increase in systolic blood pressure, DBP, HR, and SV and a decrease in total peripheral resistance in both groups. Acute exercise induced a significant impairment in PORH and ACh-induced response in rowers, but not in sedentary, whereas the SNP-induced vasodilation was not affected by acute exercise in any group. Antioxidant capacity significantly increased only in sedentary after acute exercise. Single acute exercise session impaired microvascular reactivity and endothelial function in rowers but not in sedentary, possibly due to (1) more rowing grades and higher exercise intensity achieved by rowers; (2) a higher increase in arterial pressure in rowers than in sedentary men; and (3) a lower antioxidant capacity in rowers.

Efficacy of treadmill exercises on arterial blood oxygenation, oxygen consumption and walking distance in healthy elderly people: a controlled trial.

PubMed

Bichay, Ashraf Adel Fahmy; Ramírez, Juan M; Núñez, Víctor M; Lancho, Carolina; Poblador, María S; Lancho, José L

2016-05-25

Regular physical exercise and healthy lifestyle can improve aerobic power of the elderly, although lung capacity gradually deteriorates with age. The aims of the study are: a) to evaluate the therapeutic effect of a treadmill exercise program on arterial blood oxygenation (SaO2), maximum oxygen consumption (VO2max) and maximum walking distance (MWD) in healthy elderly people; b) to examine the outcome of the program at a supervised short-term and at an unsupervised long-term. A prospective, not-randomized controlled intervention trial (NRCT) was conducted. Eighty participants were allocated into two homogeneous groups (training group, TG, n = 40; control group, CG, n = 40). Each group consisted of 20 men and 20 women. Pre-intervention measures of SaO2, VO2max and MWD were taken of each participant 1-week before the training program to establish the baseline. Also, during the training program, the participants were followed up at the 12, 30 and 48th week. The exercise program consisted of walking on a treadmill with fixed 0 % grade of inclination 3 times weekly for 48 weeks; the first 12 weeks were supervised and the remaining 36 weeks of the program were unsupervised. Participants in the control group were encouraged to walk twice a week during 45 min, and received standard recommendations for proper health. Related to the baseline, the SaO2, VO2max, and MWD is greater in the intervention group at the 12(th) (p <.001), 30(th) (p <.001) and 48(th) week (p <.001). Compared with the control group, there was also a significant improvement of SaO2, VO2max, and MWD valuesin the intervention group (p <.001) at the 12(th) (p <.001), 30(th) (p <.001) and 48(th) week (p <.001). Supervised intervention shows greater improvement of SaO2, VO2max, and MWD values than in the unsupervised one. These results show that performing moderate exercise, specifically walking 3 days a week, is highly recommended for healthy older people, improving aerobic power. Current Controlled Trials ISRCTN12621097 .

Electromyographic analysis of exercise resulting in symptoms of muscle damage.

PubMed

McHugh, M P; Connolly, D A; Eston, R G; Gleim, G W

2000-03-01

Surface electromyographic (EMG) signals were recorded from the hamstring muscles during six sets of submaximal isokinetic (2.6 rad x s(-1)) eccentric (11 men, 9 women) or concentric (6 men, 4 women) contractions. The EMG per unit torque increased during eccentric (P < 0.01) but not during concentric exercise. Similarly, the median frequency increased during eccentric (P < 0.01) but not during concentric exercise. The EMG per unit torque was lower for submaximal eccentric than maximum isometric contractions (P < 0.001), and lower for submaximal concentric than maximum isometric contractions (P < 0.01). The EMG per unit torque was lower for eccentric than concentric contractions (P < 0.05). The median frequency was higher for submaximal eccentric than maximum isometric contractions (P < 0.001); it was similar, however, between submaximal concentric and maximum isometric contractions (P = 0.07). Eccentric exercise resulted in significant isometric strength loss (P < 0.01), pain (P < 0.01) and muscle tenderness (P < 0.05). The greatest strength loss was seen 1 day after eccentric exercise, while the most severe pain and muscle tenderness occurred 2 days after eccentric exercise. A lower EMG per unit torque is consistent with the selective recruitment of a small number of motor units during eccentric exercise. A higher median frequency during eccentric contractions may be explained by selective recruitment of fast-twitch motor units. The present results are consistent with the theory that muscle damage results from excessive stress on a small number of active fibres during eccentric contractions.

Oxygen uptake kinetics and exercise capacity in children with cystic fibrosis.

PubMed

Fielding, Jeremy; Brantley, Lucy; Seigler, Nichole; McKie, Katie T; Davison, Gareth W; Harris, Ryan A

2015-07-01

Exercise capacity, an objective measure of exercise intolerance, is known to predict quality of life and mortality in cystic fibrosis (CF). The mechanisms for exercise intolerance in patients with cystic fibrosis (CF), however, have yet to be fully elucidated. Accordingly, this study sought to investigate oxygen uptake kinetics and the impact of fat-free mass (FFM) on exercise capacity in young patients with CF. 16 young patients with CF (age 13 ± 4 years; 10 female) and 15 matched controls (age 14 ± 3 years; nine female) participated. Pulmonary function and a maximal exercise test on a cycle ergometer using the Godfrey protocol were performed. Exercise capacity (VO2 peak), VO2 response time (VO2 RT), and functional VO2 gain (ΔVO2 /ΔWR) were all determined. Lung function was the only demographic parameter significantly lower (P < 0.05) in CF compared to controls. Exercise capacity was lower in CF (P < 0.014) only when VO2 peak was normalized for FFM (43.5 ± 7.7 vs. 50.6 ± 7.4 ml/kg-FFM/min) or expressed as % predicted (70.1 ± 14.3 vs. 85.4 ± 16.0%). The VO2 RT was slower (36.1 ± 15.1 vs. 25.0 ± 12.4 sec; P = 0.03) and the ΔVO2 /ΔWR slope was lower (8.4 ± 3 ml/min/watt vs. 10.1 ± 1.4 ml/min/watt; P = 0.02) in patients compared to controls, respectively. In conclusion, a delayed VO2 response time coupled with the lower functional VO2 gain (ΔVO2 /ΔWR) suggest that young patients with CF have impairment in oxygen transport and oxygen utilization by the muscles. These data in addition to differences in VO2 peak normalized for FFM provide some insight that muscle mass and muscle metabolism contribute to exercise intolerance in CF. © 2015 Wiley Periodicals, Inc.

The effects of exercise-based rehabilitation on balance and gait for stroke patients: a systematic review.

PubMed

An, Minjeong; Shaughnessy, Marianne

2011-12-01

This review evaluated the effects of balance and/or gait exercise interventions for stroke survivors and summarized the available evidence on these exercise interventions. A search for studies published between January 2001 and January 2010 was performed using the keywords stroke, walking or balance, and physical activity or exercise. Seventeen randomized clinical trials were identified. The findings suggest that initiating early rehabilitation during acute to subacute stroke recovery can improve balance and walking capacity. The findings also demonstrate that at least 1 hour, three to five times per week, of balance training and 30 minutes, three to five times per week, of gait-oriented exercise are effective to improve balance and walking. This review confirms that balance and walking capacity are improved with specific exercise modalities. A combination of balance, gait, and aerobic exercises would be ideal.

Ways of increasing muscular activity by means of isometric muscular exertion

NASA Technical Reports Server (NTRS)

Kovalik, A. V.

1980-01-01

The effect of isometric muscular exertion on the human body was investigated by having subjects perform basic movements in a sitting position in the conventional manner with additional muscle tension at 50% maximum force and at maximum force. The pulse, arterial pressure, skin temperature, respiratory rate, minute respiratory volume and electrical activity of the muscles involved were all measured. Performance of the exercises with maximum muscular exertion for 20 sec and without movement resulted in the greatest shifts in these indices; in the conventional manner substantial changes did not occur; and with isometric muscular exertion with 50% maximum force with and without movement, optimal functional shifts resulted. The latter is recommended for use in industrial exercises for the prevention of hypodynamia. Ten exercises are suggested.

Selectively bred rat model system for low and high response to exercise training

PubMed Central

Pollott, Geoffrey E.; Britton, Steven L.

2013-01-01

We initiated a large-scale bidirectional selection experiment in a genetically heterogeneous rat population (N/NIH stock, n = 152) to develop lines of low response trainers (LRT) and high response trainers (HRT) as a contrasting animal model system. Maximal treadmill running distance [meters (m)] was tested before (DIST1) and after (DIST2) standardized aerobic treadmill training over an 8 wk period (3 exercise sessions per week). Response to training was calculated as the change in exercise capacity (ΔDIST = DIST2 − DIST1). A within-family selection and rotational breeding paradigm between 10 families was practiced for both selected lines. For the founder population, exercise training produced a 140 ± 15 m gain in exercise capacity with interindividual variation ranging from −339 to +627 m. After 15 generations of selection (n = 3,114 rats), HRT rats improved 223 ± 20 m as a result of exercise training while exercise capacity declined −65 ± 15 m in LRT rats given the same absolute training environment. The narrow-sense heritability (h2) for ΔDIST was 0.10 ± 0.02. The LRT and HRT lines did not differ significantly for body weight or intrinsic (i.e., DIST1) exercise capacity. Using pedigree records the inbreeding coefficient increased at a rate of 1.7% per generation for HRT and 1.6% per generation for LRT, ∼30% slower than expected from random mating. Animal models developed from heterogeneous stock and enriched via selection, as presented here, often generate extreme values for traits of interest and may prove more useful than current models for uncovering genetic underpinnings. PMID:23715262

Exercise-based cardiac rehabilitation in patients with heart failure: a meta-analysis of randomised controlled trials between 1999 and 2013.

PubMed

Lewinter, Christian; Doherty, Patrick; Gale, Christopher P; Crouch, Simon; Stirk, Lisa; Lewin, Robert J; LeWinter, Martin M; Ades, Philip A; Køber, Lars; Bland, John M

2015-12-01

Guidelines recommend exercise-based cardiac rehabilitation (EBCR) for patients with heart failure (HF). However, established research has not investigated the longer-term outcomes including mortality and hospitalisation in light of the contemporary management of HF. This was a systematic review including a meta-analysis of EBCR on all-cause mortality, hospital admission, and standardised exercise capacity using four separate exercise tests in patients with heart failure over a minimum follow-up of six months from January 1999-January 2013. Electronic searches were performed in the databases: Medline, CENTRAL, EMBASE, CINAHL, and PsycINFO constrained to randomised controlled trials (RCTs). A total of 46 separate RCTs qualified for the meta-analysis, which employed conventional methods for binary and continuous data. The relative risk (RR) ratio for hospital admission (12 studies) was significantly reduced (RR ratio 0.65; 95% confidence interval (CI) 0.50-0.84; p = 0.001), but mortality (21 studies) was not (RR ratio 0.88; 95% CI 0.77-1.02; p = 0.08). The standardised exercise capacity (26 studies) showed a standardised mean difference (SMD) in favour of the exercise group as compared with the controls (SMD 0.98, 95% CI 0.59-1.37; p < 0.001). Women and elderly people were less frequently enrolled in the RCTs independent of the outcomes. Heterogeneity was moderate to high in the analysis of hospital admission and the standardised exercise capacity demonstrated through skewedness in their funnel plots. EBCR in patients with HF is associated with significant improvements in exercise capacity and hospital admission over a minimum of six months follow-up, but not in all-cause mortality. © The European Society of Cardiology 2014.

Effects of enhanced external counterpulsation on skeletal muscle gene expression in patients with severe heart failure.

PubMed

Melin, Michael; Montelius, Andreas; Rydén, Lars; Gonon, Adrian; Hagerman, Inger; Rullman, Eric

2018-01-01

Enhanced external counterpulsation (EECP) is a non-invasive treatment in which leg cuff compressions increase diastolic aortic pressure and coronary perfusion. EECP is offered to patients with refractory angina pectoris and increases physical capacity. Benefits in heart failure patients have been noted, but EECP is still considered to be experimental and its effects must be confirmed. The mechanism of action is still unclear. The aim of this study was to evaluate the effect of EECP on skeletal muscle gene expression and physical performance in patients with severe heart failure. Patients (n = 9) in NYHA III-IV despite pharmacological therapy were subjected to 35 h of EECP during 7 weeks. Before and after, lateral vastus muscle biopsies were obtained, and functional capacity was evaluated with a 6-min walk test. Skeletal muscle gene expression was evaluated using Affymetrix Hugene 1.0 arrays. Maximum walking distance increased by 15%, which is in parity to that achieved after aerobic exercise training in similar patients. Skeletal muscle gene expression analysis using Ingenuity Pathway Analysis showed an increased expression of two networks of genes with FGF-2 and IGF-1 as central regulators. The increase in gene expression was quantitatively small and no overlap with gene expression profiles after exercise training could be detected despite adequate statistical power. EECP treatment leads to a robust improvement in walking distance in patients with severe heart failure and does induce a skeletal muscle transcriptional response, but this response is small and with no significant overlap with the transcriptional signature seen after exercise training. © 2016 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

The influence of age, gender, and training on exercise efficiency.

PubMed

Woo, J Susie; Derleth, Christina; Stratton, John R; Levy, Wayne C

2006-03-07

The aim of this study was to determine whether changes in oxygen efficiency occur with aging or exercise training in healthy young and older subjects. Exercise capacity declines with age and improves with exercise training. Whether changes in oxygen efficiency, defined as the oxygen cost per unit work, contributes to the effects of aging or training has not yet been defined. Sixty-one healthy subjects were recruited into four groups of younger women (ages 20 to 33 years, n = 15), younger men (ages 20 to 30 years, n = 12), older women (ages 65 to 79 years, n = 16), and older men (ages 65 to 77 years, n = 18). All subjects underwent cardiopulmonary exercise testing to analyze aerobic parameters before and after three to six months of supervised aerobic exercise training. Before training, younger subjects had a much higher exercise capacity, as shown by a 42% higher peak oxygen consumption (VO2) (ml/kg/min, p < 0.0001). This was associated with an 11% lower work VO2/W (p = 0.02) and an 8% higher efficiency than older subjects (p = 0.03). With training, older subjects displayed a larger increase in peak W/kg (+29% vs. +12%, p = 0.001), a larger decrease in work VO2/W (-24% vs. -2%, p < 0.0001), and a greater improvement in exercise efficiency (+30% vs. 2%, p < 0.0001) compared to the young. Older age is associated with a decreased exercise efficiency and an increase in the oxygen cost of exercise, which contribute to a decreased exercise capacity. These age-related changes are reversed with exercise training, which improves efficiency to a greater degree in the elderly than in the young.

Left ventricular dyssynchrony in patients with normal ventricular systolic function referred for exercise echocardiography.

PubMed

Bernheim, Alain M; Nakajima, Yoshie; Pellikka, Patricia A

2008-10-01

Exercise testing is often normal despite the presence of exertional symptoms. We hypothesized that left ventricular (LV) dyssynchrony might occur in some patients in the absence of ischemia, LV dysfunction, or wide QRS, and might contribute to exertional symptoms and diminished exercise capacity. Echocardiographic parameters were assessed before and with exercise in 40 patients (age 62 +/- 8 years, 27 with exertional symptoms). All had normal clinically indicated exercise echocardiograms and narrow QRS. The time to peak systolic velocity (Ts) was measured in 12 segments to calculate the standard deviation (Ts-SD) and the maximal difference (Ts-diff). At rest, 25 patients (63%) had dyssynchrony by Ts-SD. With exercise, mean Ts-SD did not increase significantly (34.9 +/- 19.3 ms vs 39.5 +/- 27.2 ms, P = .28). However, Ts-SD increased by greater than 40% in 15 patients (37.5%), remained stable in 19 patients (47.5%), and decreased by greater than 40% in 6 patients (15%). Similar responses were observed for Ts-diff. Patients with exercise-induced dyssynchrony were not more likely to have symptoms. Exercise capacity was inversely correlated with resting Ts-SD (r = -0.37, P = .02) and resting Ts-diff (r = -0.38, P = .02), but not with exercise-induced changes in dyssynchrony. Patients with resting dyssynchrony had higher resting heart rate (73 +/- 12 vs 63 +/- 11 beats/min, P = .02). LV dyssynchrony may occur more frequently than previously thought and may develop with exercise in the absence of ischemia. Exercise-induced LV dyssynchrony was not related to exertional symptoms or exercise capacity. Patients with dyssynchrony at rest had a higher resting heart rate and achieved a lower workload; this may indicate early myocardial impairment.

Effects of Obstructive Sleep Apnea and Obesity on Exercise Function in Children

PubMed Central

Evans, Carla A.; Selvadurai, Hiran; Baur, Louise A.; Waters, Karen A.

2014-01-01

Study Objectives: Evaluate the relative contributions of weight status and obstructive sleep apnea (OSA) to cardiopulmonary exercise responses in children. Design: Prospective, cross-sectional study. Participants underwent anthropometric measurements, overnight polysomnography, spirometry, cardiopulmonary exercise function testing on a cycle ergometer, and cardiac doppler imaging. OSA was defined as ≥ 1 obstructive apnea or hypopnea per hour of sleep (OAHI). The effect of OSA on exercise function was evaluated after the parameters were corrected for body mass index (BMI) z-scores. Similarly, the effect of obesity on exercise function was examined when the variables were adjusted for OAHI. Setting: Tertiary pediatric hospital. Participants: Healthy weight and obese children, aged 7–12 y. Interventions: N/A. Measurements and Results: Seventy-one children were studied. In comparison with weight-matched children without OSA, children with OSA had a lower cardiac output, stroke volume index, heart rate, and oxygen consumption (VO2 peak) at peak exercise capacity. After adjusting for BMI z-score, children with OSA had 1.5 L/min (95% confidence interval -2.3 to -0.6 L/min; P = 0.001) lower cardiac output at peak exercise capacity, but minute ventilation and ventilatory responses to exercise were not affected. Obesity was only associated with physical deconditioning. Cardiac dysfunction was associated with the frequency of respiratory-related arousals, the severity of hypoxia, and heart rate during sleep. Conclusions: Children with OSA are exercise limited due to a reduced cardiac output and VO2 peak at peak exercise capacity, independent of their weight status. Comorbid OSA can further decrease exercise performance in obese children. Citation: Evans CA, Selvadurai H, Baur LA, Waters KA. Effects of obstructive sleep apnea and obesity on exercise function in children. SLEEP 2014;37(6):1103-1110. PMID:24882905

Cardiovascular Effects of 1 Year of Alagebrium and Endurance Exercise Training in Healthy Older Individuals

PubMed Central

Fujimoto, Naoki; Hastings, Jeffrey L.; Carrick-Ranson, Graeme; Shafer, Keri M.; Shibata, Shigeki; Bhella, Paul S.; Abdullah, Shuaib M.; Barkley, Kyler W.; Adams-Huet, Beverley; Boyd, Kara N.; Livingston, Sheryl A.; Palmer, Dean; Levine, Benjamin D.

2014-01-01

Background Lifelong exercise training maintains a youthful compliance of the left ventricle (LV), whereas a year of exercise training started later in life fails to reverse LV stiffening, possibly because of accumulation of irreversible advanced glycation end products. Alagebrium breaks advanced glycation end product crosslinks and improves LV stiffness in aged animals. However, it is unclear whether a strategy of exercise combined with alagebrium would improve LV stiffness in sedentary older humans. Methods and Results Sixty-two healthy subjects were randomized into 4 groups: sedentary+placebo; sedentary+alagebrium (200 mg/d); exercise+placebo; and exercise+alagebrium. Subjects underwent right heart catheterization to define LV pressure–volume curves; secondary functional outcomes included cardiopulmonary exercise testing and arterial compliance. A total of 57 of 62 subjects (67±6 years; 37 f/20 m) completed 1 year of intervention followed by repeat measurements. Pulmonary capillary wedge pressure and LV end-diastolic volume were measured at baseline, during decreased and increased cardiac filling. LV stiffness was assessed by the slope of LV pressure–volume curve. After intervention, LV mass and end-diastolic volume increased and exercise capacity improved (by ≈8%) only in the exercise groups. Neither LV mass nor exercise capacity was affected by alagebrium. Exercise training had little impact on LV stiffness (training×time effect, P=0.46), whereas alagebrium showed a modest improvement in LV stiffness compared with placebo (medication×time effect, P=0.04). Conclusions Alagebrium had no effect on hemodynamics, LV geometry, or exercise capacity in healthy, previously sedentary seniors. However, it did show a modestly favorable effect on age-associated LV stiffening. PMID:24130005

Relation of maximum blood pressure during exercise and regular physical activity in normotensive men with left ventricular mass and hypertrophy. MARATHOM Investigators. Medida de la Actividad fisica y su Relación Ambiental con Todos los Lípidos en el HOMbre.

PubMed

Molina, L; Elosua, R; Marrugat, J; Pons, S

1999-10-15

The relation between maximum systolic blood pressure (BP) during exercise and left ventricular (LV) mass is controversial. Physical activity also induces LV mass increase. The objective was to assess the relation between BP response to exercise and LV mass in normotensive men, taking into account physical activity practice. A cross-sectional study was performed. Three hundred eighteen healthy normotensive men, aged between 20 and 60 years, participated in this study. The Minnesota questionnaire was used to assess physical activity practice. An echocardiogram and a maximum exercise test were performed. LV mass was calculated and indexed to body surface area. LV hypertrophy was defined as a ventricular mass index > or =134 g/m2. BP was measured at the moment of maximum effort. Hypertensive response was considered when BP was > or =210 mm Hg. In the multiple linear regression model, maximum systolic BP was associated with LV mass index and correlation coefficient was 0.27 (SE 0.07). Physical activity practice and age were also associated with LV mass. An association between hypertensive response to exercise and LV hypertrophy was observed (odds ratio 3.16). Thus, BP response to exercise is associated with LV mass and men with systolic BP response > or =210 mm Hg present a 3-times higher risk of LV hypertrophy than those not reaching this limit. Physical activity practice is related to LV mass, but not to LV hypertrophy.

Neutrophil and Monocyte Bactericidal Responses to 10 Weeks of Low-Volume High-Intensity Interval or Moderate-Intensity Continuous Training in Sedentary Adults

PubMed Central

Shepherd, Sam O.; Wilson, Oliver J.; Adlan, Ahmed M.; Wagenmakers, Anton J. M.; Shaw, Christopher S.; Lord, Janet M.

2017-01-01

Neutrophils and monocytes are key components of the innate immune system that undergo age-associated declines in function. This study compared the impact of high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) on immune function in sedentary adults. Twenty-seven (43 ± 11 years) healthy sedentary adults were randomized into ten weeks of either a HIIT (>90% maximum heart rate) or MICT (70% maximum heart rate) group training program. Aerobic capacity (VO2peak), neutrophil and monocyte bacterial phagocytosis and oxidative burst, cell surface receptor expression, and systemic inflammation were measured before and after the training. Total exercise time commitment was 57% less for HIIT compared to that for MICT while both significantly improved VO2peak similarly. Neutrophil phagocytosis and oxidative burst and monocyte phagocytosis and percentage of monocytes producing an oxidative burst were improved by training similarly in both groups. Expression of monocyte but not neutrophil CD16, TLR2, and TLR4 was reduced by training similarly in both groups. No differences in systemic inflammation were observed for training; however, leptin was reduced in the MICT group only. With similar immune-enhancing effects for HIIT compared to those for MICT at 50% of the time commitment, our results support HIIT as a time efficient exercise option to improve neutrophil and monocyte function. PMID:28656073

Effect of training level and blood flow restriction on thermal parameters: Preliminary study

NASA Astrophysics Data System (ADS)

Sampaio, Lucas; Bezerra, Ewertton; Paladino, Kayo; dos Santos, João Otacílio Libardoni; Priego Quesada, Jose I.; Rossato, Mateus

2016-11-01

Training with blood flow restriction could lead to an effect on skin temperature. Additionally, this effect could be higher in people with lower physical fitness level due to their lower capacity of heat loss. The aim of this preliminary study was therefore to evaluate the effects of training experience on the acute and chronic thermal skin responses after performing exercise with and without blood flow restriction. The study included ten men, of these, five were trained. All subjects performed tests and re-tests for maximum strength (1 repetition maximum) through unilateral leg extensions (right thigh at 45 ± 6.7 kg and left thigh at 45.5 ± 8.1 kg, p > 0.05). The protocol consisted of four sets to concentric failure, with one-minute rest intervals between sets at an intensity corresponding to 40% of 1 RM. There were 7-day intervals between experimental sessions (150 mmHg versus unrestricted flow restriction). The thermal images were made before the protocol (pre), immediately after the end of the series (post), and 24 h afterward (post 24 h). When comparing temperature variation (Δ exercise and Δ 24 h) between groups, it was observed that the trained participants showed a greater drop in temperature 24 h after exercise with 150 mmHg restriction (confidence interval: 95% of Δ 24 h [-0.2 to -0.9 °C]) compared to untrained subjects (p = 0.006 and ES > 1.5, confidence interval: 95% Δ 24 h [-0.1 to 0.6 °C].) In conclusion, this preliminary study showed that training experience interferes with the chronic cutaneous thermal temperature of the anterior thigh when strength training associated with blood flow restriction 150 mmHg was performed.

Reproducibility of oxygen saturation monitoring during six-minute walk test and exercise stress test in patients with pulmonary arteriovenous malformations associated with hereditary hemorrhagic telangiectasia.

PubMed

Li, Walter; Niu, Bolin; Henderson, Katherine; Northrup, Veronika; Pollak, Jeffery S; Trow, Terence; Fahey, John; White, Robert I

2011-06-01

Patients with pulmonary arteriovenous malformations (PAVMs) are at risk for multiple complications and require close follow-up. We investigated the reproducibility of the 6-minute walk test (6MWT) and exercise stress test (EST) for the evaluation of low oxygen saturation in patients with PAVMs. Twenty-two patients with PAVMs, most of whom had hereditary hemorrhagic telangiectasia (HHT), participated in a Human Investigations Committee-approved protocol. Patients ranged from 9 to 74 years of age (mean 28) and had a broad spectrum of anatomic subtypes of PAVMs, including focal and diffuse. Standard 6MWT and cycle ergometry EST were both performed twice with adequate rest between tests. Heart rate (HR) and oxygen saturation were measured at the beginning and end of each test. Distance walked and maximum resistance was also recorded. The intraclass correlation coefficients (r(i)) at the end of 6MWT were as follows: HR (r(i) = 0.940; 95% confidence interval [CI] 0.863-0.975), oxygen saturation (r(i) = 0.973; 95% CI 0.933-0.989), and distance (r(i) = 0.942; 95% CI 0.867-0.975). The r(i)s at the end of EST were as follows: HR (r(i) = 0.941; 95% CI 0.865-0.975), oxygen saturation (r(i) = 0.993; 95% CI 0.982-0.997), and maximum resistance (r(i) = 0.941; 95% CI 0.864-0.975). 6MWT and EST were reproducible measures of exercise capacity and oxygen saturation and are potential adjunct tests in the follow-up assessment for patients with PAVMs.

Peripheral Vascular Disease: The Beneficial Effect of Exercise in Peripheral Vascular Diseases Based on Clinical Trials.

PubMed

Elnady, Basant M; Saeed, Ayman

2017-01-01

Intermittent claudication (IC) due to peripheral artery diseases (PAD) is one of the disabling disease that can affect quality of life (QOL) and functional status of capacity. It is characterized by cramping pain which develops with exercise and eliminated by rest secondary to decrease blood flow to the muscles. The annual incidence rate is increased with age. Exercise rehabilitation has a great impact in improving the functional capacity and prevent the functional disability. The available evidences from current studies have showed that exercise therapy is considered the primary treatment in PAD, which in consequently improves the QOL. In this chapter we will illustrate the current available evidences which support exercise benefit and outcomes in PAD with IC.

Fit to Forgive: Effect of Mode of Exercise on Capacity to Override Grudges and Forgiveness

PubMed Central

Struthers, C. Ward; van Monsjou, Elizabeth; Ayoub, Mariam; Guilfoyle, Joshua R.

2017-01-01

Forgiveness is important for repairing relationships that have been damaged by transgressions. In this research we explored the notion that the mode of physical exercise that victims of transgressions engage in and their capacity to override grudges are important in the process of forgiveness. Two exploratory studies that varied in samples (community non-student adults, undergraduate students) and research methods (non-experimental, experimental) were used to test these predictions. Findings showed that, compared to anaerobic or no exercise, aerobic and flexibility exercise facilitated self-control over grudges and forgiveness (Studies 1 and 2), and self-control over grudges explained the relation between exercise and forgiveness (Study 2). Possible mechanisms for future research are discussed. PMID:28533758

Variable prognostic value of blood pressure response to exercise.

PubMed

Kato, Yuko; Suzuki, Shinya; Uejima, Tokuhisa; Semba, Hiroaki; Yamashita, Takeshi

2018-01-01

The aim of this study was to evaluate the impact of patient background including exercise capacity on the relationship between the blood pressure (BP) response to exercise and prognosis in patients visiting a cardiovascular hospital. A total of 2134 patients who were referred to our hospital underwent symptom-limited maximal cardiopulmonary exercise testing, and were followed through medical records and mail. The BP response to exercise was defined as the difference between peak and rest systolic BP. The end point was set as cardiovascular events including cardiovascular death, acute coronary syndrome, hospitalization for heart failure, and cerebral infarction. During a median follow-up period of 3 years, 179 (8%) patients reached the end point (2.5%/year). Multivariate analysis showed that BP response was independently and negatively associated with the occurrence of the end point. This prognostic significance of BP response was consistent regardless of left ventricular ejection fraction, renal function, presence of heart failure symptoms, the presence of organic heart disease, and hypertension. However, peak VO 2 showed a significant interaction with the effects of BP response on the end point, suggesting that the prognostic value of BP response was limited in patients with preserved exercise capacity. The role of BP response to exercise as the predictor depends on exercise capacity of each patient. Copyright © 2017 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

The effect of habitual waterpipe tobacco smoking on pulmonary function and exercise capacity in young healthy males: A pilot study.

PubMed

Hawari, F I; Obeidat, N A; Ghonimat, I M; Ayub, H S; Dawahreh, S S

2017-01-01

Evidence regarding the health effects of habitual waterpipe smoking is limited, particularly in young smokers. Respiratory health and cardiopulmonary exercise tests were compared in young male habitual waterpipe smokers (WPS) versus non-smokers. 69 WPS (≥3 times/week for three years) and 69 non-smokers were studied. Respiratory health was assessed through the American Thoracic Society and the Division of Lung Diseases (ATS-DLD-78) adult questionnaire. Pulmonary function and cardiopulmonary exercise tests were performed. Self-reported respiratory symptoms, forced expiratory volume in first second (FEV 1 ), forced vital capacity (FVC), FEV 1 /FVC ratio, forced expiratory flow between 25 and 75% of FVC (FEF 25-75% ), peak expiratory flow (PEF), exercise time, peak end-tidal CO 2 tension (PetCO 2 ), subject-reported leg fatigue and dyspnea; peak O 2 uptake (VO 2 max), and end-expiratory lung volume (EELV) change from baseline (at peak exercise) were measured. WPS were more likely than non-smokers to report respiratory symptoms. WPS also demonstrated: shorter exercise time; lower peak VO 2 ; higher perceived dyspnea at mid-exercise; lower values of the following: FEV 1 , FVC, PEF, and EELV change. Habitual waterpipe tobacco smoking in young seemingly healthy individuals is associated with a greater burden of respiratory symptoms and impaired exercise capacity. Copyright © 2016 Elsevier Ltd. All rights reserved.

Recovery of pulmonary functions, exercise capacity, and quality of life after pulmonary rehabilitation in survivors of ARDS due to severe influenza A (H1N1) pneumonitis.

PubMed

Hsieh, Meng-Jer; Lee, Wei-Chun; Cho, Hsiu-Ying; Wu, Meng-Fang; Hu, Han-Chung; Kao, Kuo-Chin; Chen, Ning-Hung; Tsai, Ying-Huang; Huang, Chung-Chi

2018-04-20

Acute respiratory distress syndrome (ARDS) due to severe influenza A H1N1 pneumonitis would result in impaired pulmonary functions and health-related quality of life (HRQoL) after hospital discharge. The recovery of pulmonary functions, exercise capacity, and HRQoL in the survivors of ARDS due to 2009 pandemic influenza A H1N1 pneumonitis (H1N1-ARDS) was evaluated in a tertiary teaching hospital in northern Taiwan between May 2010 and June 2011. Data of spirometry, total lung capacity (TLC), diffusing capacity of carbon monoxide (DL CO ), and 6-minute walk distance (6MWD) in the patients survived from H1N1-ARDS were collected 1, 3, and 6 months post-hospital discharge. HRQoL was evaluated with St. George respiratory questionnaire (SGRQ). Nine survivors of H1N1-ARDS in the study period were included. All these patients received 2 months' pulmonary rehabilitation program. Pulmonary functions and exercise capacity included TLC, forced vital capacity (FVC), forced expiratory volume in the first second (FEV 1 ), DL CO , and 6MWD improved from 1 to 3 months post-hospital discharge. Only TLC had further significant improvement from 3 to 6 months. HRQoL represented as the total score of SGRQ had no significant improvement in the first 3 months but improved significantly from 3 to 6 months post-discharge. The impaired pulmonary functions and exercise capacity in the survivors of H1N1-ARDS improved soon at 3 months after hospital discharge. Their quality of life had keeping improved at 6 months even though there was no further improvement of their pulmonary functions and exercise capacity. © 2018 The Authors. Influenza and Other Respiratory Viruses Published by John Wiley & Sons Ltd.

Sweat Rates During Continuous and Interval Aerobic Exercise: Implications for NASA Multipurpose Crew Vehicle (MPCV) Missions

NASA Technical Reports Server (NTRS)

Ryder, Jeffrey W.; Scott, Jessica; Ploutz-Snyder, Robert; Ploutz-Snyder, Lori L.

2016-01-01

Aerobic deconditioning is one of the effects spaceflight. Impaired crewmember performance due to loss of aerobic conditioning is one of the risks identified for mitigation by the NASA Human Research Program. Missions longer than 8 days will involve exercise countermeasures including those aimed at preventing the loss of aerobic capacity. The NASA Multipurpose Crew Vehicle (MPCV) will be NASA's centerpiece architecture for human space exploration beyond low Earth orbit. Aerobic exercise within the small habitable volume of the MPCV is expected to challenge the ability of the environmental control systems, especially in terms of moisture control. Exercising humans contribute moisture to the environment by increased respiratory rate (exhaling air at 100% humidity) and sweat. Current acceptable values are based on theoretical models that rely on an "average" crew member working continuously at 75% of their aerobic capacity (Human Systems Integration Requirements Document). Evidence suggests that high intensity interval exercise for much shorter durations are equally effective or better in building and maintaining aerobic capacity. This investigation will examine sweat and respiratory rates for operationally relevant continuous and interval aerobic exercise protocols using a variety of different individuals. The results will directly inform what types of aerobic exercise countermeasures will be feasible to prescribe for crewmembers aboard the MPCV.

Astrocytic glycogen-derived lactate fuels the brain during exhaustive exercise to maintain endurance capacity

PubMed Central

Matsui, Takashi; Omuro, Hideki; Liu, Yu-Fan; Soya, Mariko; Shima, Takeru; McEwen, Bruce S.; Soya, Hideaki

2017-01-01

Brain glycogen stored in astrocytes provides lactate as an energy source to neurons through monocarboxylate transporters (MCTs) to maintain neuronal functions such as hippocampus-regulated memory formation. Although prolonged exhaustive exercise decreases brain glycogen, the role of this decrease and lactate transport in the exercising brain remains less clear. Because muscle glycogen fuels exercising muscles, we hypothesized that astrocytic glycogen plays an energetic role in the prolonged-exercising brain to maintain endurance capacity through lactate transport. To test this hypothesis, we used a rat model of exhaustive exercise and capillary electrophoresis-mass spectrometry–based metabolomics to observe comprehensive energetics of the brain (cortex and hippocampus) and muscle (plantaris). At exhaustion, muscle glycogen was depleted but brain glycogen was only decreased. The levels of MCT2, which takes up lactate in neurons, increased in the brain, as did muscle MCTs. Metabolomics revealed that brain, but not muscle, ATP was maintained with lactate and other glycogenolytic/glycolytic sources. Intracerebroventricular injection of the glycogen phosphorylase inhibitor 1,4-dideoxy-1,4-imino-d-arabinitol did not affect peripheral glycemic conditions but suppressed brain lactate production and decreased hippocampal ATP levels at exhaustion. An MCT2 inhibitor, α-cyano-4-hydroxy-cinnamate, triggered a similar response that resulted in lower endurance capacity. These findings provide direct evidence for the energetic role of astrocytic glycogen-derived lactate in the exhaustive-exercising brain, implicating the significance of brain glycogen level in endurance capacity. Glycogen-maintained ATP in the brain is a possible defense mechanism for neurons in the exhausted brain. PMID:28515312

Astrocytic glycogen-derived lactate fuels the brain during exhaustive exercise to maintain endurance capacity.

PubMed

Matsui, Takashi; Omuro, Hideki; Liu, Yu-Fan; Soya, Mariko; Shima, Takeru; McEwen, Bruce S; Soya, Hideaki

2017-06-13

Brain glycogen stored in astrocytes provides lactate as an energy source to neurons through monocarboxylate transporters (MCTs) to maintain neuronal functions such as hippocampus-regulated memory formation. Although prolonged exhaustive exercise decreases brain glycogen, the role of this decrease and lactate transport in the exercising brain remains less clear. Because muscle glycogen fuels exercising muscles, we hypothesized that astrocytic glycogen plays an energetic role in the prolonged-exercising brain to maintain endurance capacity through lactate transport. To test this hypothesis, we used a rat model of exhaustive exercise and capillary electrophoresis-mass spectrometry-based metabolomics to observe comprehensive energetics of the brain (cortex and hippocampus) and muscle (plantaris). At exhaustion, muscle glycogen was depleted but brain glycogen was only decreased. The levels of MCT2, which takes up lactate in neurons, increased in the brain, as did muscle MCTs. Metabolomics revealed that brain, but not muscle, ATP was maintained with lactate and other glycogenolytic/glycolytic sources. Intracerebroventricular injection of the glycogen phosphorylase inhibitor 1,4-dideoxy-1,4-imino-d-arabinitol did not affect peripheral glycemic conditions but suppressed brain lactate production and decreased hippocampal ATP levels at exhaustion. An MCT2 inhibitor, α-cyano-4-hydroxy-cinnamate, triggered a similar response that resulted in lower endurance capacity. These findings provide direct evidence for the energetic role of astrocytic glycogen-derived lactate in the exhaustive-exercising brain, implicating the significance of brain glycogen level in endurance capacity. Glycogen-maintained ATP in the brain is a possible defense mechanism for neurons in the exhausted brain.

Strength-Power Performance of Visually Impaired Paralympic and Olympic Judo Athletes From the Brazilian National Team: A Comparative Study.

PubMed

Loturco, Irineu; Nakamura, Fábio Y; Winckler, Ciro; Bragança, Jaime R; da Fonseca, Roger A; Moraes-Filho, Josué; Zaccani, Wagner A; Kobal, Ronaldo; Cal Abad, Cesar C; Kitamura, Katia; Pereira, Lucas A; Franchini, Emerson

2017-03-01

Loturco, I, Nakamura, FY, Winckler, C, Bragança, JR, da Fonseca, RA, Filho, JM, Zaccani, WA, Kobal, R, Cal Abad, CC, Kitamura, K, Pereira, LA, and Franchini, E. Strength-power performance of visually impaired paralympic and olympic judo athletes from the brazilian national team: a comparative study. J Strength Cond Res 31(3): 743-749, 2017-The aim of this study was to compare the muscle power and maximal isometric strength capacities of Olympic and visually impaired Paralympic judo athletes. Twenty-eight elite judo athletes (7 men and 7 women per group) from the permanent Brazilian National Paralympic and Olympic teams took part in this study. After a specific warm-up, the athletes performed loaded jump squat (JS), bench press (BP), and standing barbell row (SBR) exercises to determine their values of maximum mean propulsive power (MPP) in these respective exercises. The maximal isometric strength (MIS) was also determined for both upper and lower limbs, through the use of BP and half-squat (HS) exercises. Finally, the jumping ability was assessed using unloaded squat jump (SJ). The magnitude-based inference was used to compare the groups. The Olympic judo athletes presented a likely higher SJ height than the Paralympic athletes. The Olympic group presented almost certainly higher MPP in the loaded JS and in the SBR exercises and likely higher MPP in the BP exercise. Importantly, in the MIS assessments the differences between groups in the HS and BP exercises were rated as unclear. In conclusion, our results showed that both Olympic and Paralympic judo athletes present similar levels of maximal isometric strength, but muscle power performance is superior in Olympic athletes.

The effects of high-intensity exercise on neural responses to images of food.

PubMed

Crabtree, Daniel R; Chambers, Edward S; Hardwick, Robert M; Blannin, Andrew K

2014-02-01

Acute bouts of high-intensity exercise modulate peripheral appetite regulating hormones to transiently suppress hunger. However, the effects of physical activity on central appetite regulation have yet to be fully investigated. We used functional magnetic resonance imaging (fMRI) to compare neural responses to visual food stimuli after intense exercise and rest. Fifteen lean healthy men [mean ± SD age: 22.5 ± 3.1 y; mean ± SD body mass index (in kg/m(2)): 24.2 ± 2.4] completed two 60-min trials-exercise (EX; running at ∼70% maximum aerobic capacity) and a resting control trial (REST)-in a counterbalanced order. After each trial, an fMRI assessment was completed in which images of high- and low-calorie foods were viewed. EX significantly suppressed subjective appetite responses while increasing thirst and core-body temperature. Furthermore, EX significantly suppressed ghrelin concentrations and significantly enhanced peptide YY release. Neural responses to images of high-calorie foods significantly increased dorsolateral prefrontal cortex activation and suppressed orbitofrontal cortex (OFC) and hippocampus activation after EX compared with REST. After EX, low-calorie food images increased insula and putamen activation and reduced OFC activation compared with REST. Furthermore, left pallidum activity was significantly elevated after EX when low-calorie images were viewed and was suppressed when high-calorie images were viewed, and these responses correlated significantly with thirst. Exercise increases neural responses in reward-related regions of the brain in response to images of low-calorie foods and suppresses activation during the viewing of high-calorie foods. These central responses are associated with exercise-induced changes in peripheral signals related to appetite-regulation and hydration status. This trial was registered at www.clinicaltrials.gov as NCT01926431.

“Nutraceuticals” in relation to human skeletal muscle and exercise

PubMed Central

Deane, Colleen S.; Wilkinson, Daniel J.; Phillips, Bethan E.; Smith, Kenneth; Etheridge, Timothy

2017-01-01

Skeletal muscles have a fundamental role in locomotion and whole body metabolism, with muscle mass and quality being linked to improved health and even lifespan. Optimizing nutrition in combination with exercise is considered an established, effective ergogenic practice for athletic performance. Importantly, exercise and nutritional approaches also remain arguably the most effective countermeasure for muscle dysfunction associated with aging and numerous clinical conditions, e.g., cancer cachexia, COPD, and organ failure, via engendering favorable adaptations such as increased muscle mass and oxidative capacity. Therefore, it is important to consider the effects of established and novel effectors of muscle mass, function, and metabolism in relation to nutrition and exercise. To address this gap, in this review, we detail existing evidence surrounding the efficacy of a nonexhaustive list of macronutrient, micronutrient, and “nutraceutical” compounds alone and in combination with exercise in relation to skeletal muscle mass, metabolism (protein and fuel), and exercise performance (i.e., strength and endurance capacity). It has long been established that macronutrients have specific roles and impact upon protein metabolism and exercise performance, (i.e., protein positively influences muscle mass and protein metabolism), whereas carbohydrate and fat intakes can influence fuel metabolism and exercise performance. Regarding novel nutraceuticals, we show that the following ones in particular may have effects in relation to 1) muscle mass/protein metabolism: leucine, hydroxyl β-methylbutyrate, creatine, vitamin-D, ursolic acid, and phosphatidic acid; and 2) exercise performance: (i.e., strength or endurance capacity): hydroxyl β-methylbutyrate, carnitine, creatine, nitrates, and β-alanine. PMID:28143855

Predictive Accuracy of Exercise Stress Testing the Healthy Adult.

ERIC Educational Resources Information Center

Lamont, Linda S.

1981-01-01

Exercise stress testing provides information on the aerobic capacity, heart rate, and blood pressure responses to graded exercises of a healthy adult. The reliability of exercise tests as a diagnostic procedure is discussed in relation to sensitivity and specificity and predictive accuracy. (JN)

[Ergometric results of r-erythropoietin treatment of hemodialysis patients].

PubMed

Hortian, B; Schmidt, R; Wüstenberg, P W; Dörp, E; Schumann, L; Winkler, R; Klinkmann, H

1990-05-15

To investigate the effect of partial correction of anemia in patients maintained by chronic intermittent hemodialysis on exercise capacity, patients underwent a bicycle acido-ergometry before and after treatment with recombinant human erythropoietin. The results demonstrate a (subjective) improvement of exercise capacity without any evidence for that in the pH values.

Exercise Training for Heart Failure Patients with and without Systolic Dysfunction: An Evidence-Based Analysis of How Patients Benefit

PubMed Central

Smart, Neil

2011-01-01

Significant benefits can be derived by heart failure patients from exercise training. This paper provides an evidence-based assessment of expected clinical benefits of exercise training for heart failure patients. Meta-analyses and randomized, controlled trials of exercise training in heart failure patients were reviewed from a search of PubMed, Cochrane Controlled Trial Registry (CCTR), CINAHL, and EMBASE. Exercise training improves functional capacity, quality of life, hospitalization, and systolic and diastolic function in heart failure patients. Heart failure patients with preserved systolic function (HFnEF) participating in exercise training studies are more likely to be women and are 5–7 years older than their systolic heart failure (CHF) counterparts. All patients exhibit low functional capacities, although in HFnEF patients this may be age related, therefore subtle differences in exercise prescriptions are required. Published works report that exercise training is beneficial for heart failure patients with and without systolic dysfunction. PMID:20953365

Predictive factors for work capacity in patients with musculoskeletal disorders.

PubMed

Lydell, Marie; Baigi, Amir; Marklund, Bertil; Månsson, Jörgen

2005-09-01

To identify predictive factors for work capacity in patients with musculoskeletal disorders. A descriptive, evaluative, quantitative study. The study was based on 385 patients who participated in a rehabilitation programme. Patients were divided into 2 groups depending on their ability to work. The groups were compared with each other with regard to sociodemographic factors, diagnoses, disability pension and number of sick days. The patient's level of exercise habits, ability to undertake activities, physical capacity, pain and quality of life were compared further using logistic regression analysis. Predictive factors for work capacity, such as ability to undertake activities, quality of life and fitness on exercise, were identified as important independent factors. Other well-known factors, i.e. gender, age, education, pain and earlier sickness certification periods, were also identified. Factors that were not significantly different between the groups were employment status, profession, diagnosis and levels of exercise habits. Identifying predictors for ability to return to work is an essential task for deciding on suitable individual rehabilitation. This study identified new predictive factors, such as ability to undertake activities, quality of life and fitness on exercise.

Benefits of physical exercise training on cognition and quality of life in frail older adults.

PubMed

Langlois, Francis; Vu, Thien Tuong Minh; Chassé, Kathleen; Dupuis, Gilles; Kergoat, Marie-Jeanne; Bherer, Louis

2013-05-01

Frailty is a state of vulnerability associated with increased risks of fall, hospitalization, cognitive deficits, and psychological distress. Studies with healthy senior suggest that physical exercise can help improve cognition and quality of life. Whether frail older adults can show such benefits remains to be documented. A total of 83 participants aged 61-89 years were assigned to an exercise-training group (3 times a week for 12 weeks) or a control group (waiting list). Frailty was determined by a complete geriatric examination using specific criteria. Pre- and post-test measures assessed physical capacity, cognitive performance, and quality of life. Compared with controls, the intervention group showed significant improvement in physical capacity (functional capacities and physical endurance), cognitive performance (executive functions, processing speed, and working memory), and quality of life (global quality of life, leisure activities, physical capacity, social/family relationships, and physical health). Benefits were overall equivalent between frail and nonfrail participants. Physical exercise training leads to improved cognitive functioning and psychological well-being in frail older adults.

Functional pools of oxidative and glycolytic fibers in human muscle observed by 31P magnetic resonance spectroscopy during exercise.

PubMed Central

Park, J H; Brown, R L; Park, C R; McCully, K; Cohn, M; Haselgrove, J; Chance, B

1987-01-01

Quantitative probing of heterogeneous regions in muscle is feasible with phosphorus-31 magnetic resonance spectroscopy because of the differentiation of metabolic patterns of glycolytic and oxidative fibers. A differential recruitment of oxidative and glycolytic fibers during exercise was demonstrated in 4 of 10 untrained young men by following changes in phosphate metabolites. Concentrations of inorganic phosphate (Pi), phosphocreatine, and ATP were estimated in the wrist flexor muscles of the forearm at rest, during two cycles of three grades of exercise, and in recovery. At high work levels (40% of maximum strength), two distinct Pi peaks were observed and identified with Pi pools at pH 6.9 and pH 5.9-6.4, respectively. These could be accounted for as follows. At the lowest level of work (using 20% of maximum strength), early recruitment primarily of oxidative (type I) and possibly some intermediate (type IIA) muscle fibers occurs with relatively little net lactate production and consequently little decrease in pH. At higher work loads, however, primarily glycolytic (type IIB) muscle fibers are recruited, which have relatively high net lactate production and therefore generate a second pool of Pi at low pH. ATP depletion (35-54%) and Pi losses accompanied the reduction in ability to perform during the first exercise cycle. When the cycle of graded exercise was repeated immediately, the total Pi remained high but gave rise to only one peak at pH 6.8-7.0. These observations indicated exhaustion of glycolytic type IIB fibers, removal of lactate by high local blood flow, and sustained contractions largely by oxidative type I and IIA fibers. A functional differentiation of fiber types could also be demonstrated during recovery if exercise was stopped while two pools of Pi were still apparent. In the first 3 min of recovery, the Pi peak at pH 6.8-6.9 disappeared almost entirely, whereas the Pi peak at pH 6.0 remained unaltered, reflecting the faster recovery of oxidative type I fibers. The potential of magnetic resonance spectroscopy to characterize oxidative and glycolytic fibers, predict capacity for aerobic performance, and signal the presence of muscle pathology is discussed. PMID:3480522

Exercise response in Parkinson’s disease: insights from a cross-sectional comparison with sedentary controls and a per-protocol analysis of a randomised controlled trial

PubMed Central

Collett, Johnny; Franssen, Marloes; Meaney, Andy; Sexton, Claire; Dennis-West, Andrea; Betts, Jill F; Izadi, Hooshang; Bogdanovic, Marko; Tims, Martin; Farmer, Andrew; Dawes, Helen

2017-01-01

Objectives To investigate the acute and adaptation cardiovascular and metabolic training responses in people with Parkinson’s disease (pwP). Design (1) A cross-sectional study of exercise response of pwP compared with sedentary controls and (2) an interventional study of exercise training in pwP. Setting Community leisure facilities. Participants pwP (n=83) and sedentary controls (n=55). Interventions Study 1 included participants from a two-arm-parallel single-blind phase II randomised controlled trial (RCT), that undertook a baseline maximal incremental exercise test and study 2 included those randomised to the exercise group in the RCT, who completed a 6-month weekly exercise programme (n=37). The intervention study 2 was a prescribed exercise program consisting of sessions lasting 60 min, two times a week over a 6-month period. The control group followed the same protocol which derived the same cardiorespiratory parameters, except that they were instructed to aim for a cadence of ~60 revolutions per minute and the unloaded phase lasted 3 min with an initial step of 25 W. Primary and secondary outcome measures Stepwise incremental exercise test to volitional exhaustion was the primary outcome measure. Results Study 1 showed higher maximum values for heart rate (HR), VO2 L/min, VCO2 L/min and ventilation L/min for the control group; respiratory exchange ratio (RER), perceived exertion and O2 pulse (VO2 L/min/HR) did not differ between groups. In study 2, for pwP who adhered to training (n=37), RER increased significantly and although there was no significant change in aerobic capacity or HR response, reduced blood pressure was found. Conclusions An abnormal cardiovascular response to exercise was observed in pwP compared to controls. After the exercise programme, metabolic deficiencies remained for pwP. These observations add to the pathogenic understanding of PD, acknowledge an underling metabolic contribution and support that certain cardiovascular symptoms may improve as a result of this type of exercise. PMID:29282259

[Effects of an inpatient pulmonary rehabilitation program on dyspnea, exercise capacity, and health related quality of life for patients with chronic lung disease].

PubMed

Lee, Chang Kwan

2007-04-01

The purpose of this study was to examine the effects of an inpatient pulmonary rehabilitation program on dyspnea, exercise capacity, and health related quality of life in inpatients with chronic lung disease. This quasi experimental study was designed with a nonequivalent control group pre-post test time series. Twenty three patients were assigned to the experimental group and nineteen to the control group. The inpatient pulmonary rehabilitation program was composed of upper and lower extremity exercise, breathing retraining, inspiratory muscle training, education, relaxation and telephone contacts. This program consisted of 4 sessions with inpatients and 4 weeks at home after discharge. The control group was given a home based pulmonary rehabilitation program at the time of discharge. The outcomes were measured by the Borg score, 6MWD and the Chronic Respiratory Disease Questionnaire(CRQ). There was a statistically significant difference in dyspnea between the experimental group and control group, but not among time sequence, or interaction between groups and time sequence. Also significant improvements in exercise capacity and health related quality of life were found only in the experimental group. An Inpatient pulmonary rehabilitation program may be a useful intervention to reduce dyspnea, and increase exercise capacity and health related quality of life for chronic lung disease patients.

Physical function was related to mortality in patients with chronic kidney disease and dialysis.

PubMed

Morishita, Shinichiro; Tsubaki, Atsuhiro; Shirai, Nobuyuki

2017-10-01

Previous studies have shown that exercise improves aerobic capacity, muscular functioning, cardiovascular function, walking capacity, and health-related quality of life (QOL) in patients with chronic kidney disease (CKD) and dialysis. Recently, additional studies have shown that higher physical activity contributes to survival and decreased mortality as well as physical function and QOL in patients with CKD and dialysis. Herein, we review the evidence that physical function and physical activity play an important role in mortality for patients with CKD and dialysis. During November 2016, Medline and Web of Science databases were searched for published English medical reports (without a time limit) using the terms "CKD" or "dialysis" and "mortality" in conjunction with "exercise capacity," "muscle strength," "activities of daily living (ADL)," "physical activity," and "exercise." Numerous studies suggest that higher exercise capacity, muscle strength, ADL, and physical activity contribute to lower mortality in patients with CKD and dialysis. Physical function is associated with mortality in patients with CKD and dialysis. Increasing physical function may decrease the mortality rate of patients with CKD and dialysis. Physicians and medical staff should recognize the importance of physical function in CKD and dialysis. In addition, exercise is associated with reduced mortality among patients with CKD and dialysis. © 2017 International Society for Hemodialysis.

77 FR 12823 - Solicitation of Comments on a Proposed Change to the Disclosure Limitation Policy for Information...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-02

... policy for information reported on fuel ethanol production capacity, (both nameplate and maximum... fuel ethanol production capacity, (both nameplate and maximum sustainable capacity) on Form EIA-819 as... treat all information reported on fuel ethanol production capacity, (both nameplate and maximum...

Effect of prolonged exercise on oxidative damage and susceptibility to oxidants of rat tissues in severe hyperthyroidism.

PubMed

Venditti, P; De Rosa, R; Caldarone, G; Di Meo, S

2005-10-15

We investigated effects of prolonged aerobic exercise and severe hyperthyroidism on indices of oxidative damage, susceptibility to oxidants, and respiratory capacity of homogenates from rat liver, heart and skeletal muscle. Both treatments induced increases in hydroperoxide and protein-bound carbonyl levels. Moreover, the highest increases were found when hyperthyroid animals were subjected to exercise. These changes, which were associated to reduced exercise endurance capacity, were in part due to higher susceptibility to oxidants of hyperthyroid tissues. Levels of oxidative damage indices were scarcely related to changes in antioxidant enzyme activities and lipid-soluble antioxidant concentrations. However, the finding that, following exercise the scavenger levels generally decreased in liver homogenates and increased in heart and muscles ones, suggested a net shuttle of antioxidants from liver to other tissues under need. Aerobic capacity, evaluated by cytochrome oxidase activity, was not modified by exercise, which, conversely, affected the rates of oxygen consumption of hyperthyroid preparations. These results seem to confirm the higher susceptibility of hyperthyroid tissues to oxidative challenge, because the mechanisms underlying the opposite changes in respiration rates during State 4 and State 3 likely involve oxidative modifications of components of mitochondrial respiratory chain, different from cytochrome aa3.

Relationship between nutritional risk and exercise capacity in severe chronic obstructive pulmonary disease in male patients

PubMed Central

Shan, Xizheng; Liu, Jinming; Luo, Yanrong; Xu, Xiaowen; Han, Zhiqing; Li, Hailing

2015-01-01

Objective The nutritional status of chronic obstructive pulmonary disease (COPD) patients is associated with their exercise capacity. In the present study, we have explored the relationship between nutritional risk and exercise capacity in severe male COPD patients. Methods A total of 58 severe COPD male patients were enrolled in this study. The patients were assigned to no nutritional risk group (n=33) and nutritional risk group (n=25) according to the Nutritional Risk Screening (NRS, 2002) criteria. Blood gas analysis, conventional pulmonary function testing, and cardiopulmonary exercise testing were performed on all the patients. Results Results showed that the weight and BMI of the patients in the nutritional risk group were significantly lower than in the no nutritional risk group (P<0.05). The pulmonary diffusing capacity for carbon monoxide of the no nutritional risk group was significantly higher than that of the nutritional risk group (P<0.05). Besides, the peak VO2 (peak oxygen uptake), peak O2 pulse (peak oxygen pulse), and peak load of the nutritional risk group were significantly lower than those of the no nutritional risk group (P<0.05) and there were significantly negative correlations between the NRS score and peak VO2, peak O2 pulse, or peak load (r<0, P<0.05). Conclusion The association between exercise capacity and nutritional risk based on NRS 2002 in severe COPD male patients is supported by these results of this study. PMID:26150712

Iron Deficiency Is a Determinant of Functional Capacity and Health-related Quality of Life 30 Days After an Acute Coronary Syndrome.

PubMed

Meroño, Oona; Cladellas, Mercè; Ribas-Barquet, Núria; Poveda, Paula; Recasens, Lluis; Bazán, Víctor; García-García, Cosme; Ivern, Consol; Enjuanes, Cristina; Orient, Salvador; Vila, Joan; Comín-Colet, Josep

2017-05-01

Iron deficiency (ID) is a prevalent condition in patients with ischemic heart disease and heart failure. Little is known about the impact of ID on exercise capacity and quality of life (QoL) in the recovery phase after an acute coronary syndrome (ACS). Iron status and its impact on exercise capacity and QoL were prospectively evaluated in 244 patients 30 days after the ACS. QoL was assessed by the standard EuroQoL-5 dimensions, EuroQoL visual analogue scale, and Heart-QoL questionnaires. Exercise capacity was analyzed by treadmill/6-minute walk tests. The effect of ID on cardiovascular mortality and readmission rate was also investigated. A total of 46% of the patients had ID. These patients had lower exercise times (366±162 vs 462±155seconds; P<.001), metabolic consumption rates (7.9±2.9 vs 9.3±2.6 METS; P=.003), and EuroQoL-5 dimensions (0.76±0.25 vs 0.84±0.16), visual analogue scale (66±16 vs 72±17), and Heart-QoL (1.9±0.6 vs 2.2±0.6) scores (P<.05). ID independently predicted lower exercise times (OR, 2.9; 95%CI, 1.1-7.6; P=.023) and worse QoL (OR, 1.9; 95%CI, 1.1-3.3; P<.001) but had no effect on cardiovascular morbidity or mortality. ID, a prevalent condition in ACS patients, results in a poorer mid-term functional recovery, as measured by exercise capacity and QoL. Copyright © 2016 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

Wii-Workouts on Chronic Pain, Physical Capabilities and Mood of Older Women: A Randomized Controlled Double Blind Trial.

PubMed

Monteiro-Junior, Renato Sobral; de Souza, Cíntia Pereira; Lattari, Eduardo; Rocha, Nuno Barbosa Ferreira; Mura, Gioia; Machado, Sérgio; da Silva, Elirez Bezerra

2015-01-01

Chronic Low Back Pain (CLBP) is a public health problem and older women have higher incidence of this symptom, which affect body balance, functional capacity and behavior. The purpose of this study was to verifying the effect of exercises with Nintendo Wii on CLBP, functional capacity and mood of elderly. Thirty older women (68 ± 4 years; 68 ± 12 kg; 154 ± 5 cm) with CLBP participated in this study. Elderly individuals were divided into a Control Exercise Group (n = 14) and an Experimental Wii Group (n = 16). Control Exercise Group did strength exercises and core training, while Experimental Wii Group did ones additionally to exercises with Wii. CLBP, balance, functional capacity and mood were assessed pre and post training by the numeric pain scale, Wii Balance Board, sit to stand test and Profile of Mood States, respectively. Training lasted eight weeks and sessions were performed three times weekly. MANOVA 2 x 2 showed no interaction on pain, siting, stand-up and mood (P = 0.53). However, there was significant difference within groups (P = 0.0001). ANOVA 2 x 2 showed no interaction for each variable (P > 0.05). However, there were significant differences within groups in these variables (P < 0.05). Tukey's post-hoc test showed significant difference in pain on both groups (P = 0.0001). Wilcoxon and Mann-Whitney tests identified no significant differences on balance (P > 0.01). Capacity to Sit improved only in Experimental Wii Group (P = 0.04). In conclusion, physical exercises with Nintendo Wii Fit Plus additional to strength and core training were effective only for sitting capacity, but effect size was small.

Exercise capacity and progression from prehypertension to hypertension.

PubMed

Faselis, Charles; Doumas, Michael; Kokkinos, John Peter; Panagiotakos, Demosthenes; Kheirbek, Raya; Sheriff, Helen M; Hare, Katherine; Papademetriou, Vasilios; Fletcher, Ross; Kokkinos, Peter

2012-08-01

Prehypertension is likely to progress to hypertension. The rate of progression is determined mostly by age and resting blood pressure but may also be attenuated by increased fitness. A graded exercise test was performed in 2303 men with prehypertension at the Veterans Affairs Medical Centers in Washington, DC. Four fitness categories were defined, based on peak metabolic equivalents (METs) achieved. We assessed the association between exercise capacity and rate of progression to hypertension (HTN). The median follow-up period was 7.8 years (mean (± SD) 9.2±6.1 years). The incidence rate of progression from prehypertension to hypertension was 34.4 per 1000 person-years. Exercise capacity was a strong and independent predictor of the rate of progression. Compared to the High-Fit individuals (>10.0 METs), the adjusted risk for developing HTN was 66% higher (hazard ratio, 1.66; 95% CI, 1.2 to 2.2; P=0.001) for the Low-Fit and, similarly, 72% higher (hazard ratio, 1.72; 95% CI, 1.2 to 2.3; P=0.001) for the Least-Fit individuals, whereas it was only 36% for the Moderate-Fit (hazard ratio, 1.36; 95% CI, 0.99 to 1.80; P=0.056). Significant predictors for the progression to HTN were also age (19% per 10 years), resting systolic blood pressure (16% per 10 mm Hg), body mass index (15.3% per 5 U), and type 2 diabetes mellitus (2-fold). In conclusion, an inverse, S-shaped association was shown between exercise capacity and the rate of progression from prehypertension to hypertension in middle-aged and older male veterans. The protective effects of fitness were evident when exercise capacity exceeded 8.5 METs. These findings emphasize the importance of fitness in the prevention of hypertension.

Hippocampal-Brainstem Connectivity Associated with Vagal Modulation after an Intense Exercise Intervention in Healthy Men

PubMed Central

Bär, Karl-Jürgen; Herbsleb, Marco; Schumann, Andy; de la Cruz, Feliberto; Gabriel, Holger W.; Wagner, Gerd

2016-01-01

Regular physical exercise leads to increased vagal modulation of the cardiovascular system. A combination of peripheral and central processes has been proposed to underlie this adaptation. However, specific changes in the central autonomic network have not been described in human in more detail. We hypothesized that the anterior hippocampus known to be influenced by regular physical activity might be involved in the development of increased vagal modulation after a 6 weeks high intensity intervention in young healthy men (exercise group: n = 17, control group: n = 17). In addition to the determination of physical capacity before and after the intervention, we used resting state functional magnetic resonance imaging and simultaneous heart rate variability assessment. We detected a significant increase of the power output at the anaerobic threshold of 11.4% (p < 0.001), the maximum power output Pmax of 11.2% (p < 0.001), and VO2max adjusted for body weight of 4.7% (p < 0.001) in the exercise group (EG). Comparing baseline (T0) and post-exercise (T1) values of parasympathetic modulation of the exercise group, we observed a trend for a decrease in heart rate (p < 0.06) and a significant increase of vagal modulation as indicated by RMSSD (p < 0.026) during resting state. In the whole brain analysis, we found that the connectivity pattern of the right anterior hippocampus (aHC) was specifically altered to the ventromedial anterior cortex, the dorsal striatum and to the dorsal vagal complex (DVC) in the brainstem. Moreover, we observed a highly significant negative correlation between increased RMSSD after exercise and decreased functional connectivity from the right aHC to DVC (r = −0.69, p = 0.003). This indicates that increased vagal modulation was associated with functional connectivity between aHC and the DVC. In conclusion, our findings suggest that exercise associated changes in anterior hippocampal function might be involved in increased vagal modulation. PMID:27092046

Exercise capacity and all-cause mortality in male veterans with hypertension aged ≥70 years.

PubMed

Faselis, Charles; Doumas, Michael; Pittaras, Andreas; Narayan, Puneet; Myers, Jonathan; Tsimploulis, Apostolos; Kokkinos, Peter

2014-07-01

Aging, even in otherwise healthy subjects, is associated with declines in muscle mass, strength, and aerobic capacity. Older individuals respond favorably to exercise, suggesting that physical inactivity plays an important role in age-related functional decline. Conversely, physical activity and improved exercise capacity are associated with lower mortality risk in hypertensive individuals. However, the effect of exercise capacity in older hypertensive individuals has not been investigated extensively. A total of 2153 men with hypertension, aged ≥70 years (mean, 75 ± 4) from the Washington, DC, and Palo Alto Veterans Affairs Medical Centers, underwent routine exercise tolerance testing. Peak workload was estimated in metabolic equivalents (METs). Fitness categories were established based on peak METs achieved, adjusted for age: very-low-fit, 2.0 to 4.0 METs (n=386); low-fit, 4.1 to 6.0 METs (n=1058); moderate-fit, 6.1 to 8.0 METs (n=495); high-fit >8.0 METs (n=214). Cox proportional hazard models were applied after adjusting for age, body mass index, race, cardiovascular disease, cardiovascular medications, and risk factors. All-cause mortality was quantified during a mean follow-up period of 9.0 ± 5.5 years. There were a total of 1039 deaths or 51.2 deaths per 1000 person-years of follow-up. Mortality risk was 11% lower (hazard ratio, 0.89; 95% confidence interval, 0.86-0.93; P<0.001) for every 1-MET increase in exercise capacity. When compared with those achieving ≤4.0 METs, mortality risk was 18% lower (hazard ratio, 0.82; 95% confidence interval, 0.70-0.95; P=0.011) for the low-fit, 36% for the moderate-fit (hazard ratio, 0.64; 95% confidence interval, 0.52-0.78; P<0.001), and 48% for the high-fit individuals (hazard ratio, 0.52; 95% confidence interval, 0.39-0.69; P<0.001). These findings suggest that exercise capacity is associated with lower mortality risk in elderly men with hypertension. © 2014 American Heart Association, Inc.

Aortic valve prosthesis-patient mismatch and exercise capacity in adult patients with congenital heart disease.

PubMed

van Slooten, Ymkje J; van Melle, Joost P; Freling, Hendrik G; Bouma, Berto J; van Dijk, Arie Pj; Jongbloed, Monique Rm; Post, Martijn C; Sieswerda, Gertjan T; Huis In 't Veld, Anna; Ebels, Tjark; Voors, Adriaan A; Pieper, Petronella G

2016-01-01

To report the prevalence of aortic valve prosthesis-patient mismatch (PPM) in an adult population with congenital heart disease (CHD) and its impact on exercise capacity. Adults with congenital heart disease (ACHD) with a history of aortic valve replacement may outgrow their prosthesis later in life. However, the prevalence and clinical consequences of aortic PPM in ACHD are presently unknown. From the national Dutch Congenital Corvitia (CONCOR) registry, we identified 207 ACHD with an aortic valve prosthesis for this cross-sectional cohort study. Severe PPM was defined as an indexed effective orifice area ≤0.65 cm2/m2 and moderate PPM as an indexed orifice area ≤0.85 cm2/m2 measured using echocardiography. Exercise capacity was reported as percentage of predicted exercise capacity (PPEC). Of the 207 patients, 68% was male, 71% had a mechanical prosthesis and mean age at inclusion was 43.9 years ±11.4. The prevalence of PPM was 42%, comprising 23% severe PPM and 19% moderate PPM. Prevalence of PPM was higher in patients with mechanical prostheses (p<0.001). PPM was associated with poorer exercise capacity (mean PPEC 84% vs. 92%; p=0.048, mean difference =-8.3%, p=0.047). Mean follow-up was 2.6±1.1 years during which New York Heart Association (NYHA) class remained stable in most patients. PPM showed no significant effect on death or hospitalisation during follow-up (p=0.218). In this study we report a high prevalence (42%) of PPM in ACHD with an aortic valve prosthesis and an independent association of PPM with diminished exercise capacity. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

The impact of iron deficiency and anaemia on exercise capacity and outcomes in patients with chronic heart failure. Results from the Studies Investigating Co-morbidities Aggravating Heart Failure.

PubMed

Ebner, Nicole; Jankowska, Ewa A; Ponikowski, Piotr; Lainscak, Mitja; Elsner, Sebastian; Sliziuk, Veronika; Steinbeck, Lisa; Kube, Jennifer; Bekfani, Tarek; Scherbakov, Nadja; Valentova, Miroslava; Sandek, Anja; Doehner, Wolfram; Springer, Jochen; Anker, Stefan D; von Haehling, Stephan

2016-02-15

Anaemia and iron deficiency (ID) are important co-morbidities in patients with chronic heart failure (HF) and both may lead to reduced exercise capacity. We enrolled 331 out-patients with stable chronic HF (mean age: 64 ± 11 years, 17% female, left ventricular ejection fraction [LVEF] 35 ± 13%, body mass index [BMI] 28.5 ± 5.2 kg/m(2), New York Heart Association [NYHA] class 2.2 ± 0.7, chronic kidney disease 35%, glomerular filtration rate 61.7 ± 20.1 mL/min). Anaemia was defined according to World Health Organization criteria (haemoglobin [Hb] < 13 g/dL in men, < 12 g/dL in women). ID was defined as serum ferritin < 100 μg/L or ferritin < 300 μg/L with transferrin saturation (TSAT) < 20%. Exercise capacity was assessed as peak oxygen consumption (peak VO2) by spiroergometry and 6-minute walk test (6MWT). A total of 91 (27%) patients died from any cause during a mean follow-up of 18 months. At baseline, 98 (30%) patients presented with anaemia and 149 (45%) patients presented with ID. We observed a significant reduction in exercise capacity in parallel to decreasing Hb levels (r = 0.24, p < 0.001). In patients with anaemia and ID (n = 63, 19%), exercise capacity was significantly lower than in patients with ID or anaemia only. Cox regression analysis showed that after adjusting for NYHA, age, hsCRP and creatinine anaemia is an independent predictor of mortality in patients with HF (hazard ratio [HR]: 0.56, 95% confidence interval [CI]: 0.33-0.97, p = 0.04). The impact of anaemia on reduced exercise capacity and on mortality is stronger than that of ID. Anaemia remained an independent predictor of death after adjusting for clinically relevant variables. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Nutritional status is related to fat-free mass, exercise capacity and inspiratory strength in severe chronic obstructive pulmonary disease patients.

PubMed

Sabino, Pollyane Galinari; Silva, Bruno Moreira; Brunetto, Antonio Fernando

2010-06-01

Being overweight or obese is associated with a higher rate of survival in patients with advanced chronic obstructive pulmonary disease (COPD). This paradoxical relationship indicates that the influence of nutritional status on functional parameters should be further investigated. To investigate the impact of nutritional status on body composition, exercise capacity and respiratory muscle strength in severe chronic obstructive pulmonary disease patients. Thirty-two patients (nine women) were divided into three groups according to their body mass indices (BMI): overweight/obese (25 < or = BMI < or = 34.9 kg/m(2), n=8), normal weight (18.5 < or = BMI < or = 24.9 kg/m(2), n=17) and underweight (BMI <18.5 kg/m(2), n=7). Spirometry, bioelectrical impedance, a six-minute walking distance test and maximal inspiratory and expiratory pressures were assessed. Airway obstruction was similar among the groups (p=0.30); however, overweight/obese patients had a higher fat-free mass (FFM) index [FFMI=FFM/body weight(2) (mean+/-SEM: 17+/-0.3 vs. 15+/-0.3 vs. 14+/-0.5 m/kg(2), p<0.01)], exercise capacity (90+/-8 vs. 79+/-6 vs. 57+/-8 m, p=0.02) and maximal inspiratory pressure (63+/-7 vs. 57+/-5 vs. 35+/-8 % predicted, p=0.03) in comparison to normal weight and underweight patients, respectively. In addition, on backward multiple regression analysis, FFMI was the unique independent predictor of exercise capacity (partial r=0.52, p<0.01). Severe chronic obstructive pulmonary disease (COPD) patients who were overweight or obese had a greater FFM, exercise capacity and inspiratory muscle strength than patients with the same degree of airflow obstruction who were of normal weight or underweight, and higher FFM was independently associated with higher exercise capacity. These characteristics of overweight or obese patients might counteract the drawbacks of excess weight and lead to an improved prognosis in COPD.

Integrative Conductance of Oxygen During Exercise at Altitude.

PubMed

Calbet, José A L; Lundby, Carsten; Boushel, Robert

2016-01-01

In the oxygen (O2) cascade downstream steps can never achieve higher flows of O2 than the preceding ones. At the lung the transfer of O2 is determined by the O2 gradient between the alveolar space and the lung capillaries and the O2 diffusing capacity (DLO2). While DLO2 may be increased several times during exercise by recruiting more lung capillaries and by increasing the oxygen carrying capacity of blood due to higher peripheral extraction of O2, the capacity to enhance the alveolocapillary PO2 gradient is more limited. The transfer of oxygen from the alveolar space to the hemoglobin (Hb) must overcome first the resistance offered by the alveolocapillary membrane (1/DM) and the capillary blood (1/θVc). The fractional contribution of each of these two components to DLO2 remains unknown. During exercise these resistances are reduced by the recruitment of lung capillaries. The factors that reduce the slope of the oxygen dissociation curve of the Hb (ODC) (i.e., lactic acidosis and hyperthermia) increase 1/θVc contributing to limit DLO2. These effects are accentuated in hypoxia. Reducing the size of the active muscle mass improves pulmonary gas exchange during exercise and reduces the rightward shift of the ODC. The flow of oxygen from the muscle capillaries to the mitochondria is pressumably limited by muscle O2 conductance (DmcO2) (an estimation of muscle oxygen diffusing capacity). However, during maximal whole body exercise in normoxia, a higher flow of O2 is achieved at the same pressure gradients after increasing blood [Hb], implying that in healthy humans exercising in normoxia there is a functional reserve in DmcO2. This conclusion is supported by the fact that during small muscle exercise in chronic hypoxia, peak exercise DmcO2 is similar to that observed during exercise in normoxia despite a markedly lower O2 pressure gradient driving diffusion.

Evaluating pulmonary function, aerobic capacity, and pediatric quality of life following a 10-week aerobic exercise training in school-aged asthmatics: a randomized controlled trial.

PubMed

Abdelbasset, Walid K; Alsubaie, Saud F; Tantawy, Sayed A; Abo Elyazed, Tamer I; Kamel, Dalia M

2018-01-01

It has been documented that aerobic exercise may increase pulmonary functions and aerobic capacity, but limited data has evaluated a child's satisfaction and pediatric quality of life (PQoL) with exercise training. This study aimed to investigate the effects of moderate-intensity exercise training on asthmatic school-aged children. This study included 38 school-aged children with asthma (23 males and 15 females) aged between 8-12 years. They were randomly assigned to two groups, aerobic exercise (AE) and conventional treatment (Con ttt) groups. The AE group received a program of moderate-intensity aerobic exercise for 10 weeks with asthma medications and the Con ttt group received only asthma medications without exercise intervention. A home respiratory exercise was recommended for the two groups. Aerobic capacity was investigated using maximal oxygen uptake (VO 2max ), 6-minute walk test (6MWT), and fatigue index. PQoL was evaluated using Pediatric Quality of Life Questionnaire (PQoLQ). Also, pulmonary function tests were performed, and the results recorded. The findings of this study showed significant improvements in pulmonary functions and VO 2max in the two groups; however, this improvement was significantly higher in the AE group than in the Con ttt group ( p <0.05). The 6MWT and fatigue index improved in the AE group ( p <0.05) but not in the Con ttt group ( p >0.05). All dimensions of PQoL significantly improved in the AE group ( p <0.05), but there was no significant improvement in the Con ttt group after the 10-week intervention period ( p >0.05). Ten weeks of physical exercise had beneficial effects on pulmonary functions, aerobic capacity, and PQoL in school-aged children with asthma. Effort and awareness should be dedicated to encouraging the active lifestyle among different populations, especially asthmatic children.

PubMed Central

Nozaki, S.; Kawai, M.; Shimoyama, R.; Futamura, N.; Matsumura, T.; Adachi, K.; Kikuchi, Y.

2010-01-01

The purpose of this study is to evaluate whether the range of motion exercise of the temporo-mandibular joint (jaw ROM exercise) with a hot pack and massage of the masseter muscle improve biting disorder in Duchenne muscular dystrophy (DMD). The subjects were 18 DMD patients (21.3 ± 4.1 years old). The jaw ROM exercise consisted of therapist-assisted training (2 times a week) and self-training (before each meal every day). The therapist-assisted training consisted of the application of a hot pack on the cheek of the masseter muscle region (15 minutes), the massage of the masseter (10 minutes), and jaw ROM exercise (5 minutes). The self-training involved jaw ROM exercise by opening the mouth to the maximum degree, ten times. These trainings continued for six months. Outcomes were evaluated by measuring the greatest occlusal force and the distance at the maximum degree of mouth opening between an incisor of the top and that of the bottom. Six months later, the greatest occlusal force had increased significantly compared with that at the start of jaw ROM exercise (intermediate values: from 73.8N to 97.3N) (p = 0.005) as determined by the Friedman test and Scheffé's nonparametric test. The patients' satisfaction with meals increased. However, the maximum degree of mouth opening did not change after six months of jaw ROM exercise. Jaw ROM exercise in DMD is effective for increasing the greatest occlusal force. PMID:21574523

Diet composition and the performance of high-intensity exercise.

PubMed

Maughan, R J; Greenhaff, P L; Leiper, J B; Ball, D; Lambert, C P; Gleeson, M

1997-06-01

The crucial role of muscle glycogen as a fuel during prolonged exercise is well established, and the effects of acute changes in dietary carbohydrate intake on muscle glycogen content and on endurance capacity are equally well known. More recently, it has been recognized that diet can also affect the performance of high-intensity exercise of short (2-7 min) duration. If the muscle glycogen content is lowered by prolonged (1-1.5 h) exhausting cycle exercise, and is subsequently kept low for 3-4 days by consumption of a diet deficient in carbohydrate (< 5% of total energy intake), there is a dramatic (approximately 10-30%) reduction in exercise capacity during cycling sustainable for about 5 min. The same effect is observed if exercise is preceded by 3-4 days on a carbohydrate-restricted diet or by a 24 h total fast without prior depletion of the muscle glycogen. Consumption of a diet high in carbohydrate (70% of total energy intake from carbohydrate) for 3-4 days before exercise improves exercise capacity during high-intensity exercise, although this effect is less consistent. The blood lactate concentration is always lower at the point of fatigue after a diet low in carbohydrate and higher after a diet high in carbohydrate than after a normal diet. Even when the duration of the exercise task is kept constant, the blood lactate concentration is higher after exercise on a diet high in carbohydrate than on a diet low in carbohydrate. Consumption of a low-carbohydrate isoenergetic diet is achieved by an increased intake of protein and fat. A high-protein diet, particularly when combined with a low carbohydrate intake, results in metabolic acidosis, which ensues within 24 h and persists for at least 4 days. This appears to be the result of an increase in the circulating concentrations of strong organic acids, particularly free fatty acids and 3-hydroxybutyrate, together with an increase in the total plasma protein concentration. This acidosis, rather than any decrease in the muscle glycogen content, may be responsible for the reduced exercise capacity in high-intensity exercise; this may be due to a reduced rate of efflux of lactate and hydrogen ions from the working muscles. Alternatively, the accumulation of acetyl groups in the carbohydrate-deprived state may reduce substrate flux through the pyruvate dehydrogenase complex, thus reducing aerobic energy supply and accelerating the onset of fatigue.

Exercise-induced oxyhaemoglobin desaturation, ventilatory limitation and lung diffusing capacity in women during and after exercise.

PubMed

Walls, Justin; Maskrey, Michael; Wood-Baker, Richard; Stedman, Wade

2002-06-01

Arterial haemoglobin saturation during exercise in healthy young women [eight subjects mean (SEM) age 20.8 (1.8) years] was measured to confirm the theory that young women experience exercise-induced arterial hypoxaemia (EIAH) at a lower relative percentage of maximal oxygen uptake (VO(2max)) than has been documented in their male counterparts. To determine if flow limitation [the percentage of the tidal volume ( V(T)) that met or exceeded the boundary established by multiple maximal expiratory manoeuvres] and/or post-exercise lung diffusing capacity are linked to EIAH in women, and to investigate the influence of exercise intensity and duration on post-exercise carbon monoxide lung diffusing capacity ( D(L, CO)), these parameters were measured during and after three exercise tests (incremental test until exhaustion, 5 km run and 5 km run with sprint). All subjects experienced physiologically significant EIAH (a fall of more than 3% in oxygen saturation of arterial blood from levels at rest) and seven subjects experienced flow limitation during the VO(2max) protocol [mean (SD) 12.2 (8.8)% of V(T)]. Even though there was no significant relationship between aerobic capacity and the degree of flow limitation ( r=0.33, P>0.05), the flow limitation was related to absolute ventilation in the subjects studied ( r=0.82, P<0.05). There was no significant relationship between decrements in post exercise D(L, CO) and EIAH ( r=0.05, P>0.05), however there was a strong correlation between the extent of flow limitation (% of V(T)) and EIAH ( r=0.71). Significant decreases in D(L, CO) lasted for up to 16 h after each of the exercise tests ( P<0.05) and lasted for a further 8 h after the maximal test ( P<0.05). Exercise intensity was the main contributing factor to the observed decreases in post-exercise D(L, CO) with the percentage of VO(2max) attained during the various tests being significantly related to the fall in D(L, CO) for 1, 2, 3, 16 and 24 h after exercise ( P<0.05). As the appearance of flow limitation closely coincided with the appearance of EIAH, the results from the present study suggest that flow limitation is a contributing factor to EIAH in women although the exact mechanism remains unclear.

Improvements in exercise performance with high-intensity interval training coincide with an increase in skeletal muscle mitochondrial content and function.

PubMed

Jacobs, Robert Acton; Flück, Daniela; Bonne, Thomas Christian; Bürgi, Simon; Christensen, Peter Møller; Toigo, Marco; Lundby, Carsten

2013-09-01

Six sessions of high-intensity interval training (HIT) are sufficient to improve exercise capacity. The mechanisms explaining such improvements are unclear. Accordingly, the aim of this study was to perform a comprehensive evaluation of physiologically relevant adaptations occurring after six sessions of HIT to determine the mechanisms explaining improvements in exercise performance. Sixteen untrained (43 ± 6 ml·kg(-1)·min(-1)) subjects completed six sessions of repeated (8-12) 60 s intervals of high-intensity cycling (100% peak power output elicited during incremental maximal exercise test) intermixed with 75 s of recovery cycling at a low intensity (30 W) over a 2-wk period. Potential training-induced alterations in skeletal muscle respiratory capacity, mitochondrial content, skeletal muscle oxygenation, cardiac capacity, blood volumes, and peripheral fatigue resistance were all assessed prior to and again following training. Maximal measures of oxygen uptake (Vo2peak; ∼8%; P = 0.026) and cycling time to complete a set amount of work (∼5%; P = 0.008) improved. Skeletal muscle respiratory capacities increased, most likely as a result of an expansion of skeletal muscle mitochondria (∼20%, P = 0.026), as assessed by cytochrome c oxidase activity. Skeletal muscle deoxygenation also increased while maximal cardiac output, total hemoglobin, plasma volume, total blood volume, and relative measures of peripheral fatigue resistance were all unaltered with training. These results suggest that increases in mitochondrial content following six HIT sessions may facilitate improvements in respiratory capacity and oxygen extraction, and ultimately are responsible for the improvements in maximal whole body exercise capacity and endurance performance in previously untrained individuals.

Evaluation of left ventricular performance during supine exercise by transoesophageal M-mode echocardiography in normal subjects.

PubMed Central

Matsumoto, M; Hanrath, P; Kremer, P; Tams, C; Langenstein, B A; Schlüter, M; Weiter, R; Bleifeld, W

1982-01-01

In order to evaluate left ventricular function during dynamic exercise transoesophageal M-mode recordings of the left ventricle were carried out with a newly developed transducer gastroscope system. Twelve healthy subjects performed a graded supine bicycle exercise test. Stable and good quality images of the left ventricle at rest and during exercise at different steps up to a maximum workload of 100 watts were obtained in all patients. Isotonic maximum exercise resulted in a significant increase in fractional shortening of the left ventricle, peak shortening rate, and peak lengthening rate of the left ventricular minor axis. Left ventricular end-diastolic dimension decreased significantly. With increasing workload the pressure rate product increased significantly. It is concluded that transoesophageal M-mode echocardiography is a useful method of evaluating left ventricular performance during dynamic exercise. Images PMID:7082515

Range of motion exercise of temporo-mandibular joint with hot pack increases occlusal force in patients with Duchenne muscular dystrophy.

PubMed

Nozaki, S; Kawai, M; Shimoyama, R; Futamura, N; Matsumura, T; Adachi, K; Kikuchi, Y

2010-12-01

The purpose of this study is to evaluate whether the range of motion exercise of the temporo-mandibular joint (jaw ROM exercise) with a hot pack and massage of the masseter muscle improve biting disorder in Duchenne muscular dystrophy (DMD). The subjects were 18 DMD patients (21.3+/- 4.1 years old). The jaw ROM exercise consisted of therapist-assisted training (2 times a week) and self-training (before each meal every day). The therapist-assisted training consisted of the application of a hot pack on the cheek of the masseter muscle region (15 minutes), the massage of the masseter (10 minutes), and jaw ROM exercise (5 minutes). The self-training involved jaw ROM exercise by opening the mouth to the maximum degree, ten times. These trainings continued for six months. Outcomes were evaluated by measuring the greatest occlusal force and the distance at the maximum degree of mouth opening between an incisor of the top and that of the bottom. Six months later, the greatest occlusal force had increased significantly compared with that at the start of jaw ROM exercise (intermediate values: from 73.8N to 97.3N) (p = 0.005) as determined by the Friedman test and Scheffi's nonparametric test. The patients' satisfaction with meals increased. However, the maximum degree of mouth opening did not change after six months of jaw ROM exercise. Jaw ROM exercise in DMD is effective for increasing the greatest occlusal force.

Nutritional status, functional capacity and exercise rehabilitation in end-stage renal disease.

PubMed

Mercer, T H; Koufaki, P; Naish, P F

2004-05-01

A significant percentage of patients with end-stage renal disease are malnourished and/or muscle wasted. Uremia is associated with decreased protein synthesis and increased protein degradation. Fortunately, nutritional status has been shown to be a modifiable risk factor in the dialysis population. It has long been proposed that exercise could positively alter the protein synthesis-degradation balance. Resistance training had been considered as the only form of exercise likely to induce anabolism in renal failure patients. However, a small, but growing, body of evidence indicates that for some dialysis patients, favourable improvements in muscle atrophy and fibre hypertrophy can be achieved via predominantly aerobic exercise training. Moreover, some studies tentatively suggest that nutritional status, as measured by SGA, can also be modestly improved by modes and patterns of exercise training that have been shown to also increase muscle fibre cross-sectional area and improve functional capacity. Functional capacity tests can augment the information content of basic nutritional status assessments of dialysis patients and as such are recommended for routine inclusion as a feature of all nutritional status assessments.

Prediction of Maximum Oxygen Consumption from Walking, Jogging, or Running.

ERIC Educational Resources Information Center

Larsen, Gary E.; George, James D.; Alexander, Jeffrey L.; Fellingham, Gilbert W.; Aldana, Steve G.; Parcell, Allen C.

2002-01-01

Developed a cardiorespiratory endurance test that retained the inherent advantages of submaximal testing while eliminating reliance on heart rate measurement in predicting maximum oxygen uptake (VO2max). College students completed three exercise tests. The 1.5-mile endurance test predicted VO2max from submaximal exercise without requiring heart…

Exercise for Those with Chronic Heart Failure: Matching Programs to Patients.

ERIC Educational Resources Information Center

Braith, Randy W.

2002-01-01

Exercise training increases functional capacity and improves symptoms in selected patients with chronic heart failure and moderate-to-severe left ventricular systolic dysfunction. Aerobic training forms the basis of such a program. This paper describes contributors to exercise intolerance, responses to exercise training, favorable outcomes with…

Exercise Programming for Cardiacs--A New Direction for Physical Therapists.

ERIC Educational Resources Information Center

Gutin, Bernard

This speech begins with the presentation of a conceptual scheme of the physical working capacity of a person starting a training program. The scheme shows that after exercise, when recovery begins and sufficient time elapses, the individual recovers and adapts to a level of physical working capacity which is higher than his starting level. From…

Can a Home-based Cardiac Physical Activity Program Improve the Physical Function Quality of Life in Children with Fontan Circulation?

PubMed

Jacobsen, Roni M; Ginde, Salil; Mussatto, Kathleen; Neubauer, Jennifer; Earing, Michael; Danduran, Michael

2016-01-01

Patients after Fontan operation for complex congenital heart disease (CHD) have decreased exercise capacity and report reduced health-related quality of life (HRQOL). Studies suggest hospital-based cardiac physical activity programs can improve HRQOL and exercise capacity in patients with CHD; however, these programs have variable adherence rates. The impact of a home-based cardiac physical activity program in Fontan survivors is unclear. This pilot study evaluated the safety, feasibility, and benefits of an innovative home-based physical activity program on HRQOL in Fontan patients. A total of 14 children, 8-12 years, with Fontan circulation enrolled in a 12-week moderate/high intensity home-based cardiac physical activity program, which included a home exercise routine and 3 formalized in-person exercise sessions at 0, 6, and 12 weeks. Subjects and parents completed validated questionnaires to assess HRQOL. The Shuttle Test Run was used to measure exercise capacity. A Fitbit Flex Activity Monitor was used to assess adherence to the home activity program. Of the 14 patients, 57% were male and 36% had a dominant left ventricle. Overall, 93% completed the program. There were no adverse events. Parents reported significant improvement in their child's overall HRQOL (P < .01), physical function (P < .01), school function (P = .01), and psychosocial function (P < .01). Patients reported no improvement in HRQOL. Exercise capacity, measured by total shuttles and exercise time in the Shuttle Test Run and calculated VO2 max, improved progressively from baseline to the 6 and 12 week follow up sessions. Monthly Fitbit data suggested adherence to the program. This 12-week home-based cardiac physical activity program is safe and feasible in preteen Fontan patients. Parent proxy-reported HRQOL and objective measures of exercise capacity significantly improved. A 6-month follow up session is scheduled to assess sustainability. A larger study is needed to determine the applicability and reproducibility of these findings in other age groups and forms of complex CHD. © 2016 Wiley Periodicals, Inc.

The Role of Exercise in Cardiac Aging: From Physiology to Molecular Mechanisms

PubMed Central

Roh, Jason; Rhee, James; Chaudhari, Vinita; Rosenzweig, Anthony

2015-01-01

Aging induces structural and functional changes in the heart that are associated with increased risk of cardiovascular disease and impaired functional capacity in the elderly. Exercise is a diagnostic and therapeutic tool, with the potential to provide insights into clinical diagnosis and prognosis, as well as the molecular mechanisms by which aging influences cardiac physiology and function. In this review, we first provide an overview of how aging impacts the cardiac response to exercise and the implications this has for functional capacity in older adults. We then review the underlying molecular mechanisms by which cardiac aging contributes to exercise intolerance, and conversely how exercise training can potentially modulate aging phenotypes in the heart. Finally, we highlight the potential use of these exercise models to complement models of disease in efforts to uncover new therapeutic targets to prevent or treat heart disease in the aging population. PMID:26838314

The Role of Exercise in Cardiac Aging: From Physiology to Molecular Mechanisms.

PubMed

Roh, Jason; Rhee, James; Chaudhari, Vinita; Rosenzweig, Anthony

2016-01-22

Aging induces structural and functional changes in the heart that are associated with increased risk of cardiovascular disease and impaired functional capacity in the elderly. Exercise is a diagnostic and therapeutic tool, with the potential to provide insights into clinical diagnosis and prognosis, as well as the molecular mechanisms by which aging influences cardiac physiology and function. In this review, we first provide an overview of how aging impacts the cardiac response to exercise, and the implications this has for functional capacity in older adults. We then review the underlying molecular mechanisms by which cardiac aging contributes to exercise intolerance, and conversely how exercise training can potentially modulate aging phenotypes in the heart. Finally, we highlight the potential use of these exercise models to complement models of disease in efforts to uncover new therapeutic targets to prevent or treat heart disease in the aging population. © 2016 American Heart Association, Inc.

Exercise in space: the European Space Agency approach to in-flight exercise countermeasures for long-duration missions on ISS.

PubMed

Petersen, Nora; Jaekel, Patrick; Rosenberger, Andre; Weber, Tobias; Scott, Jonathan; Castrucci, Filippo; Lambrecht, Gunda; Ploutz-Snyder, Lori; Damann, Volker; Kozlovskaya, Inessa; Mester, Joachim

2016-01-01

To counteract microgravity (µG)-induced adaptation, European Space Agency (ESA) astronauts on long-duration missions (LDMs) to the International Space Station (ISS) perform a daily physical exercise countermeasure program. Since the first ESA crewmember completed an LDM in 2006, the ESA countermeasure program has strived to provide efficient protection against decreases in body mass, muscle strength, bone mass, and aerobic capacity within the operational constraints of the ISS environment and the changing availability of on-board exercise devices. The purpose of this paper is to provide a description of ESA's individualised approach to in-flight exercise countermeasures and an up-to-date picture of how exercise is used to counteract physiological changes resulting from µG-induced adaptation. Changes in the absolute workload for resistive exercise, treadmill running and cycle ergometry throughout ESA's eight LDMs are also presented, and aspects of pre-flight physical preparation and post-flight reconditioning outlined. With the introduction of the advanced resistive exercise device (ARED) in 2009, the relative contribution of resistance exercise to total in-flight exercise increased (33-46 %), whilst treadmill running (42-33 %) and cycle ergometry (26-20 %) decreased. All eight ESA crewmembers increased their in-flight absolute workload during their LDMs for resistance exercise and treadmill running (running speed and vertical loading through the harness), while cycle ergometer workload was unchanged across missions. Increased or unchanged absolute exercise workloads in-flight would appear contradictory to typical post-flight reductions in muscle mass and strength, and cardiovascular capacity following LDMs. However, increased absolute in-flight workloads are not directly linked to changes in exercise capacity as they likely also reflect the planned, conservative loading early in the mission to allow adaption to µG exercise, including personal comfort issues with novel exercise hardware (e.g. the treadmill harness). Inconsistency in hardware and individualised support concepts across time limit the comparability of results from different crewmembers, and questions regarding the difference between cycling and running in µG versus identical exercise here on Earth, and other factors that might influence in-flight exercise performance, still require further investigation.

Role of the cardio-pulmonary exercise test and six-minute walking test in the evaluation of exercise performance in patients with late-onset Pompe disease.

PubMed

Crescimanno, G; Modica, R; Lo Mauro, R; Musumeci, O; Toscano, A; Marrone, O

2015-07-01

In patients with late-onset Pompe disease, we explored the role of the Cardiopulmonary Exercise Test (CPET) and the Six-Minute Walking Test (6MWT) in the assessment of exercise capacity and in the evaluation of the effects of enzyme replacement therapy (ERT). Eight patients affected by late-onset Pompe disease, followed up at the Centre for Neuromuscular Diseases and treated with ERT, underwent a baseline evaluation with a spirometry, a CPET and a 6MWT. Four of them were restudied after 36 months of treatment. Three patients showed a reduction in exercise capacity as evaluated by peak oxygen uptake (VO2) measured at the CPET and Distance Walked (DW) measured at the 6MWT (median % predicted: 67.1 [range 54.3-99.6] and 67.3 [56.6-82.6], respectively). Cardiac and respiratory limitations revealed by the CPET were correlated to peak VO2, but not to the DW. Nevertheless, percent of predicted values of peak VO2 and DW were strongly correlated (rho = 0.85, p = 0.006), and close to identity. In the longitudinal evaluation forced vital capacity decreased, while peak VO2 and DW showed a trend to a parallel improvement. We concluded that although only the CPET revealed causes of exercise limitation, which partially differed among patients, CPET and 6MWT showed a similar overall degree of exercise impairment. That held true in the longitudinal assessment during ERT, where both tests demonstrated similar small improvements, occurring despite deterioration in forced vital capacity. Copyright © 2015 Elsevier B.V. All rights reserved.

No effect of group-based aerobic interval training on N-terminal pro- B-type natriuretic peptide levels in patients with chronic heart failure.

PubMed

Nilsson, Birgitta Blakstad; Westheim, Arne; Risberg, May Arna; Arnesen, Harald; Seljeflot, Ingebjørg

2010-08-01

Exercise training might improve cardiac function as well as functional capacity in patients with chronic heart failure (CHF). N-terminal pro-B-type natriuretic peptide (NT pro-BNP), is associated with the severity of the disease, and has been reported to be an independent predictor of outcome in CHF. We evaluated the effect of a four months group-based aerobic interval training program on circulating levels of NT pro-BNP in patients with CHF. We have previously reported improved functional capacity in 80 patients after exercise in this exercise program. Seventy-eight patients with stable CHF (21% women; 70+/-8 years; left ventricular ejection fraction 30+/-8.6%) on optimal medical treatment were randomized either to interval training (n=39), or to a control group (n=39). Circulating levels of NT pro-BNP, a six minute walk test (6MWT) and cycle ergometer test were evaluated at baseline, post exercise, and further after 12 months. There were no significant differences in NT pro-BNP levels from baseline to either post exercise or long-term follow-up between or within the groups. Inverse correlations were observed between NT pro-BNP and 6MWT (r=-0.24, p=0.035) and cycle exercise time (r=-0.48, p<0.001) at baseline. But no significant correlations were observed between change in NT pro-BNP and change in functional capacity (6MWT; r=0.12, p=0.33, cycle exercise time; r=0.04, p=0.72). No significant changes in NT pro-BNP levels were observed after interval training, despite significant improvement of functional capacity.

Cardiovascular testing in Fabry disease: exercise capacity reduction, chronotropic incompetence and improved anaerobic threshold after enzyme replacement.

PubMed

Lobo, T; Morgan, J; Bjorksten, A; Nicholls, K; Grigg, L; Centra, E; Becker, G

2008-06-01

The aim of this study was to document exercise capacity and serial electrocardiogram and echocardiograph findings in a cohort of Australian patients with Fabry disease, in relation to their history of enzyme replacement therapy (ERT). Fabry disease has multifactorial effects on the cardiovascular system. Most previous studies have focused on electrocardiographic and echocardiographic parameters. Exercise capacity can be used as an integrated measure of cardiovascular function and allows the effects of treatment to be monitored. A total of 38 patients (30 men and 8 women) with Fabry disease were monitored by 12-lead electrocardiograms every 6-12 months, and by annual standardized-protocol echocardiograms. Bicycle stress tests with VO(2) max measurement and once-only 6 minutes' walk tests were also carried out in subsets of patients whose general health status allowed testing. Seventy per cent of patients met electrocardiogram criteria for left ventricular hypertrophy. Left ventricular hypertrophy on echocardiograph was present in 64% of patients (80% of men). Exercise capacity was reduced in patients with Fabry disease compared with that predicted from normative population data. Mild improvement in anaerobic threshold was seen in the first year of ERT (14.1 +/- 3.0 to 15.8 +/- 3.0, P = 0.02), but no consistent further increase was seen beyond the first year. Most patients had resting bradycardia, with impaired ability to increase heart rate during exercise. Serial testing on ERT showed an improvement in anaerobic threshold but no significant change in VO(2) max. Male patients with Fabry disease were unable to attain predicted maximal heart rate on exercise or to achieve normal exercise levels. ERT was associated with a small improvement in anaerobic threshold over the first year.

Mitochondrial and performance adaptations to exercise training in mice lacking skeletal muscle LKB1

PubMed Central

Tanner, Colby B.; Madsen, Steven R.; Hallowell, David M.; Goring, Darren M. J.; Moore, Timothy M.; Hardman, Shalene E.; Heninger, Megan R.; Atwood, Daniel R.

2013-01-01

LKB1 and its downstream targets of the AMP-activated protein kinase family are important regulators of many aspects of skeletal muscle cell function, including control of mitochondrial content and capillarity. LKB1 deficiency in skeletal and cardiac muscle (mLKB1-KO) greatly impairs exercise capacity. However, cardiac dysfunction in that genetic model prevents a clear assessment of the role of skeletal muscle LKB1 in the observed effects. Our purposes here were to determine whether skeletal muscle-specific knockout of LKB1 (skmLKB1-KO) decreases exercise capacity and mitochondrial protein content, impairs accretion of mitochondrial proteins after exercise training, and attenuates improvement in running performance after exercise training. We found that treadmill and voluntary wheel running capacity was reduced in skmLKB1-KO vs. control (CON) mice. Citrate synthase activity, succinate dehydrogenase activity, and pyruvate dehydrogenase kinase content were lower in KO vs. CON muscles. Three weeks of treadmill training resulted in significantly increased treadmill running performance in both CON and skmLKB1-KO mice. Citrate synthase activity increased significantly with training in both genotypes, but protein content and activity for components of the mitochondrial electron transport chain increased only in CON mice. Capillarity and VEGF protein was lower in skmLKB1-KO vs. CON muscles, but VEGF increased with training only in skmLKB1-KO. Three hours after an acute bout of muscle contractions, PGC-1α, cytochrome c, and VEGF gene expression all increased in CON but not skmLKB1-KO muscles. Our findings indicate that skeletal muscle LKB1 is required for accretion of some mitochondrial proteins but not for early exercise capacity improvements with exercise training. PMID:23982155

Cardiopulmonary exercise testing to evaluate the exercise capacity of patients with inoperable chronic thromboembolic pulmonary hypertension: an endothelin receptor antagonist improves the peak PETCO2.

PubMed

Hirashiki, Akihiro; Adachi, Shiro; Nakano, Yoshihisa; Kono, Yuji; Shimazu, Shuzo; Shimizu, Shinya; Morimoto, Ryota; Okumura, Takahiro; Takeshita, Kyosuke; Yamada, Sumio; Murohara, Toyoaki; Kondo, Takahisa

2014-11-24

The 6-min walking distance is often used for assessing the exercise capacity under the treatment with an endothelin receptor antagonist (ERA) in patients with chronic thromboembolic pulmonary hypertension (CTEPH). The cardiopulmonary exercise testing (CPX) was reported to be more useful for the patients with pulmonary arterial hypertension (PAH), however, few reports exist in patients with inoperable CTEPH. The aim of this study was to investigate the effects of an oral dual ERA, bosentan, on exercise capacity using CPX in patients with PAH and inoperable CTEPH. This study included all patients diagnosed with 17 PAH and 12 CTEPH in the World Health Organization functional classes II-IV who started treatment with bosentan therapy. They underwent CPX, which was performed before bosentan therapy and at 3 to 6 months of the treatment. In PAH patients, peak VO2 significantly increased after the bosentan treatment (p=0.009). On the other hand, in CTEPH patients, there were no significant differences in the peak VO2. However, the peak PETCO2 was significantly increased from 23.9±5.2 mm Hg at baseline to 29.3±10.7 mm Hg after the bosentan treatment (p=0.040). In addition, peak heart rate during exercise tended to decrease after the bosentan therapy (p=0.089). Bosentan therapy improved peak PETCO2 but not peak VO2 in patients with inoperable CTEPH. These findings demonstrated that CPX is useful for assessing the exercise capacity of patients with PAH and inoperable CTEPH under the treatment with an ERA. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

Acute effects of intradialytic aerobic exercise on solute removal, blood gases and oxidative stress in patients with chronic kidney disease.

PubMed

Böhm, Joseane; Monteiro, Mariane Borba; Andrade, Francini Porcher; Veronese, Francisco Veríssimo; Thomé, Fernando Saldanha

2017-01-01

Hemodialysis contributes to increased oxidative stress and induces transitory hypoxemia. Compartmentalization decreases the supply of solutes to the dialyzer during treatment. The aim of this study was to investigate the acute effects of intradialytic aerobic exercise on solute removal, blood gases and oxidative stress in patients with chronic kidney disease during a single hemodialysis session. Thirty patients were randomized to perform aerobic exercise with cycle ergometer for lower limbs during 30 minutes with intensity between 60-70% of maximal heart rate, or control group (CG). Blood samples were collected prior to and immediately after exercise or the equivalent time in CG. Analysis of blood and dialysate biochemistry as well as blood gases were performed. Mass removal and solute clearance were calculated. Oxidative stress was determined by lipid peroxidation and by the total antioxidant capacity. Serum concentrations of solutes increased with exercise, but only phosphorus showed a significant elevation (p = 0.035). There were no significant changes in solute removal and in the acid-base balance. Both oxygen partial pressure and saturation increased with exercise (p = 0.035 and p = 0.024, respectivelly), which did not occur in the CG. The total antioxidant capacity decreased significantly (p = 0.027). The acute intradialytic aerobic exercise increased phosphorus serum concentration and decreased total antioxidant capacity, reversing hypoxemia resulting from hemodialysis. The intradialytic exercise did not change the blood acid-base balance and the removal of solutes.

Exercise interventions in polypathological aging patients that coexist with diabetes mellitus: improving functional status and quality of life.

PubMed

Cadore, Eduardo Lusa; Izquierdo, Mikel

2015-06-01

In elderly populations, diabetes is associated with reduced muscle strength, poor muscle quality, and accelerated loss of muscle mass. In addition, diabetes mellitus increases risk for accelerated aging and for the development of frailty syndrome. This disease is also associated with a polypathological condition, and its complications progressively affect quality of life and survival. Exercise interventions, including resistance training, represent the cornerstones of diabetes management, especially in patients at severe functional decline. This review manuscript aimed to describe the beneficial effects of different exercise interventions on the functional capacity of elderly diabetics, including those at polypathological condition. The SciELO, Science Citation Index, MEDLINE, Scopus, SPORTDiscus, and ScienceDirect databases were searched from 1980 to 2015 for articles published from original scientific investigations. In addition to the beneficial effects of exercise interventions on glycemic control, and on the cardiovascular risk factors associated with diabetes, physical exercise is an effective intervention to improve muscle strength, power output, and aerobic power and functional capacity in elderly diabetic patients. Thus, a combination of resistance and endurance training is the most effective exercise intervention to promote overall physical fitness in these patients. In addition, in diabetic patients with frailty and severe functional decline, a multicomponent exercise program including strength and power training, balance exercises, and gait retraining may be an effective intervention to reduce falls and improve functional capacity and quality of life in these patients.

Regulation of fuel metabolism during exercise in hypopituitarism with growth hormone-deficiency (GHD).

PubMed

Zueger, Thomas; Loher, Hannah; Egger, Andrea; Boesch, Chris; Christ, Emanuel

2016-08-01

Growth hormone (GH) has a strong lipolytic action and its secretion is increased during exercise. Data on fuel metabolism and its hormonal regulation during prolonged exercise in patients with growth hormone deficiency (GHD) is scarce. This study aimed at evaluating the hormonal and metabolic response during aerobic exercise in GHD patients. Ten patients with confirmed GHD and 10 healthy control individuals (CI) matched for age, sex, BMI, and waist performed a spiroergometric test to determine exercise capacity (VO2max). Throughout a subsequent 120-minute exercise on an ergometer at 50% of individual VO2max free fatty acids (FFA), glucose, GH, cortisol, catecholamines and insulin were measured. Additionally substrate oxidation assessed by indirect calorimetry was determined at begin and end of exercise. Exercise capacity was lower in GHD compared to CI (VO2max 35.5±7.4 vs 41.5±5.5ml/min∗kg, p=0.05). GH area under the curve (AUC-GH), peak-GH and peak-FFA were lower in GHD patients during exercise compared to CI (AUC-GH 100±93.2 vs 908.6±623.7ng∗min/ml, p<0.001; peak-GH 1.5±1.53 vs 12.57±9.36ng/ml, p<0.001, peak-FFA 1.01±0.43 vs 1.51±0.56mmol/l, p=0.036, respectively). There were no significant differences for insulin, cortisol, catecholamines and glucose. Fat oxidation at the end of exercise was higher in CI compared to GHD patients (295.7±73.9 vs 187.82±103.8kcal/h, p=0.025). A reduced availability of FFA during a 2-hour aerobic exercise and a reduced fat oxidation at the end of exercise may contribute to the decreased exercise capacity in GHD patients. Catecholamines and cortisol do not compensate for the lack of the lipolytic action of GH in patients with GHD. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effect of a 24-week physical training programme (in water and on land) on pain, functional capacity, body composition and quality of life in women with fibromyalgia.

PubMed

Latorre, Pedro Ángel; Santos, María Aparecida; Heredia-Jiménez, Jose Maria; Delgado-Fernández, Manuel; Soto, Víctor Manuel; Mañas, Alfonso; Carbonell-Baeza, Ana

2013-01-01

To analyse the effect of a 24-week physical training programme in water and on land on women with fibromyalgia. A controlled study was conducted from December 2009 to May 2010. Seventy-two women with fibromyalgia (age: 51.79±7.87 years) were assigned to an exercise group (3 sessions/week, 2 sessions in water, 1 session on land) (n=42) and to a control group (n=30). The variables analysed were: number of tender points, visual analogue scale (VAS) of pain, algometer score, functional capacity (leg strength, hand-grip dynamometry, flexibility, agility, balance, aerobic endurance, heart response), body composition (body mass index, fat mass index, skeletal muscle mass index and percentage of body fat) and psychological variables (Fibromyalgia Impact Questionnaire [FIQ] and Short Form Health Survey 36 [SF-36]). The exercise group improved in the algometer score (p<0.001), positive tender points (p=0.005), VAS (p<0.001) and FIQ (p<0.001). Improvements were also detected in functional capacity (leg strength, p=0.001; hand-grip dynamometry, p=0.001; flexibility, p<0.001; balance, p=0.006; 6-minute walk test, p<0.001; mean heart rate, p=0.031; maximum heart rate, p<0.001 and VO2 max, p<0.001). There was a decrease in the percentage of body fat (p=0.040). There was also an improvement in the subscales of the SF-36; vitality (p=0.004), mental health (p=0.001) social role functioning (p=0.020) and general health functioning (p=0.002). The findings of this study show that a 24-week physical training programme (3 sessions/week, of which 2 sessions are in water and 1 session is on land) reduces pain and disease impact and improves functional capacity in women with fibromyalgia.

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.

Muscle metaboreceptor modulation of cutaneous active vasodilation

NASA Technical Reports Server (NTRS)

Crandall, C. G.; Stephens, D. P.; Johnson, J. M.

1998-01-01

PURPOSE: Isometric handgrip exercise in hyperthermia has been shown to reduce cutaneous vascular conductance (CVC) by inhibiting the cutaneous active vasodilator system. METHODS: To identify whether this response was initiated by muscle metaboreceptors, in seven subjects two 3-min bouts of isometric handgrip exercise in hyperthermia were performed, followed by 2 min of postexercise ischemia (PEI). An index of forearm skin blood flow (laser-Doppler flowmetry) was measured on the contralateral arm at an unblocked site and at a site at which adrenergic vasoconstrictor function was blocked via bretylium iontophoresis to reveal active cutaneous vasodilator function unambiguously. Sweat rate was measured via capacitance hygrometry, CVC was indexed from the ratio of skin blood flow to mean arterial pressure and was expressed as a percentage of maximal CVC at that site. In normothermia, neither isometric exercise nor PEI affected CVC (P > 0.05). RESULTS: The first bout of isometric handgrip exercise in hyperthermia reduced CVC at control sites and this reduction persisted through PEI (pre-exercise: 59.8 +/- 5.4, exercise: 49.8 +/- 4.9, PEI: 49.7 +/- 5.3% of maximum; both P < 0.05), whereas there were no significant changes in CVC at the bretylium treated sites. The succeeding bout of isometric exercise in hyperthermia significantly reduced CVC at both untreated (pre-exercise: 59.0 +/- 4.8, exercise: 47.3 +/- 4.0, PEI: 50.1 +/- 4.1% of maximum; both P < 0.05) and bretylium treated sites (pre-exercise: 61.4 +/- 7.3, exercise: 50.6 +/- 5.1, PEI: 53.9 +/- 6.0% of maximum, both P < 0.05). At both sites, CVC during PEI was lower than during the pre-exercise period (P < 0.05). Sweat rate rose significantly during both bouts of isometric exercise and remained elevated during PEI. CONCLUSIONS: These data suggest that the reduction in CVC during isometric exercise in hyperthermia, including the inhibition of the active vasodilator system, is primarily mediated by muscle metaboreceptors, whereas central command or muscle mechanoreceptors have less influence.

"Nutraceuticals" in relation to human skeletal muscle and exercise.

PubMed

Deane, Colleen S; Wilkinson, Daniel J; Phillips, Bethan E; Smith, Kenneth; Etheridge, Timothy; Atherton, Philip J

2017-04-01

Skeletal muscles have a fundamental role in locomotion and whole body metabolism, with muscle mass and quality being linked to improved health and even lifespan. Optimizing nutrition in combination with exercise is considered an established, effective ergogenic practice for athletic performance. Importantly, exercise and nutritional approaches also remain arguably the most effective countermeasure for muscle dysfunction associated with aging and numerous clinical conditions, e.g., cancer cachexia, COPD, and organ failure, via engendering favorable adaptations such as increased muscle mass and oxidative capacity. Therefore, it is important to consider the effects of established and novel effectors of muscle mass, function, and metabolism in relation to nutrition and exercise. To address this gap, in this review, we detail existing evidence surrounding the efficacy of a nonexhaustive list of macronutrient, micronutrient, and "nutraceutical" compounds alone and in combination with exercise in relation to skeletal muscle mass, metabolism (protein and fuel), and exercise performance (i.e., strength and endurance capacity). It has long been established that macronutrients have specific roles and impact upon protein metabolism and exercise performance, (i.e., protein positively influences muscle mass and protein metabolism), whereas carbohydrate and fat intakes can influence fuel metabolism and exercise performance. Regarding novel nutraceuticals, we show that the following ones in particular may have effects in relation to 1 ) muscle mass/protein metabolism: leucine, hydroxyl β-methylbutyrate, creatine, vitamin-D, ursolic acid, and phosphatidic acid; and 2 ) exercise performance: (i.e., strength or endurance capacity): hydroxyl β-methylbutyrate, carnitine, creatine, nitrates, and β-alanine. Copyright © 2017 the American Physiological Society.

Short Communication: HIV Patient Systemic Mitochondrial Respiration Improves with Exercise.

PubMed

Kocher, Morgan; McDermott, Mindy; Lindsey, Rachel; Shikuma, Cecilia M; Gerschenson, Mariana; Chow, Dominic C; Kohorn, Lindsay B; Hetzler, Ronald K; Kimura, Iris F

2017-10-01

In HIV-infected individuals, impaired mitochondrial function may contribute to cardiometabolic disease as well as to fatigue and frailty. Aerobic exercise improves total body energy reserves; however, its impact at the cellular level is unknown. We assessed alterations in cellular bioenergetics in peripheral blood mononuclear cells (PBMC) before and after a 12-week aerobic exercise study in sedentary HIV-infected subjects on stable antiretroviral therapy who successfully completed a 12-week aerobic exercise program. In this prospective study, participants underwent supervised 20-40 min of light aerobic exercise (walking or jogging) performed three times per week for 12 weeks, gradually increasing to maintain an intensity of 50%-80% of heart rate reserve. Maximal aerobic capacity (VO 2MAX ) was assessed by a graded exercise test on a cycle ergometer before and after completion of the study. PBMC from compliant subjects (attended at least 70% of exercise sessions) were assessed for mitochondrial respiration using the Seahorse XF24 Bio-Analyzer. Seven of 24 enrolled subjects were compliant with the exercise regimen. In these individuals, a significant increase (p = .04) in VO 2MAX over 12 weeks was found with a median increase of 14%. During the same interval, a 2.45-fold increase in PBMC mitochondrial respiratory capacity (p = .04), a 5.65-fold increase in spare respiratory capacity (p = .01), and a 3.15-fold (p = .04) increase in nonmitochondrial respiration was observed. Aerobic exercise improves respiration at the cellular level. The diagnostic and prognostic value of such improved cellular respiration in the setting of chronic HIV warrants further investigation.

Effects of curative treatment emphasizing endurance training on the performance and blood pressure of hypertensive and normotensives

NASA Technical Reports Server (NTRS)

Worms, F.

1981-01-01

The problem of normal values of blood pressure after exercise taking into account the blood pressure at the end of the exercise test is discussed. Hypertensives showed a lower working capacity than normotensives. In normotensives, however, systolic blood pressure at the end of an exercise correlated well with the working capacity. After the endurance cure submaximal blood pressure was markedly lower in hypertensives with a striking dependence on the level of initial values. Systolic blood pressure at the end of an exercise test was not changed significantly. Most probably it is not possible to overcome this malregulation in hypertensives by endurance training alone.

Use of the Frank-Starling mechanism during exercise is linked to exercise-induced changes in arterial load

PubMed Central

Chantler, Paul D.; Melenovsky, Vojtech; Schulman, Steven P.; Gerstenblith, Gary; Becker, Lewis C.; Ferrucci, Luigi; Fleg, Jerome L.; Najjar, Samer S.

2012-01-01

Effective arterial elastance(EA) is a measure of the net arterial load imposed on the heart that integrates the effects of heart rate(HR), peripheral vascular resistance(PVR), and total arterial compliance(TAC) and is a modulator of cardiac performance. To what extent the change in EA during exercise impacts on cardiac performance and aerobic capacity is unknown. We examined EA and its relationship with cardiovascular performance in 352 healthy subjects. Subjects underwent rest and exercise gated scans to measure cardiac volumes and to derive EA[end-systolic pressure/stroke volume index(SV)], PVR[MAP/(SV*HR)], and TAC(SV/pulse pressure). EA varied with exercise intensity: the ΔEA between rest and peak exercise along with its determinants, differed among individuals and ranged from −44% to +149%, and was independent of age and sex. Individuals were separated into 3 groups based on their ΔEAI. Individuals with the largest increase in ΔEA(group 3;ΔEA≥0.98 mmHg.m2/ml) had the smallest reduction in PVR, the greatest reduction in TAC and a similar increase in HR vs. group 1(ΔEA<0.22 mmHg.m2/ml). Furthermore, group 3 had a reduction in end-diastolic volume, and a blunted increase in SV(80%), and cardiac output(27%), during exercise vs. group 1. Despite limitations in the Frank-Starling mechanism and cardiac function, peak aerobic capacity did not differ by group because arterial-venous oxygen difference was greater in group 3 vs. 1. Thus the change in arterial load during exercise has important effects on the Frank-Starling mechanism and cardiac performance but not on exercise capacity. These findings provide interesting insights into the dynamic cardiovascular alterations during exercise. PMID:22003052

Ability of exercise testing to predict cardiovascular and all-cause death in asymptomatic women: a 20-year follow-up of the lipid research clinics prevalence study.

PubMed

Mora, Samia; Redberg, Rita F; Cui, Yadong; Whiteman, Maura K; Flaws, Jodi A; Sharrett, A Richey; Blumenthal, Roger S

2003-09-24

The value of exercise testing in women has been questioned. To determine the prognostic value of exercise testing in a population-based cohort of asymptomatic women followed up for 20 years. Near-maximal Bruce-protocol treadmill test data from the Lipid Research Clinics Prevalence Study (1972-1976) with follow-up through 1995. A total of 2994 asymptomatic North American women, aged 30 to 80 years, without known cardiovascular disease. Cardiovascular and all-cause mortality. There were 427 (14%) deaths during 20 years of follow-up, of which 147 were due to cardiovascular causes. Low exercise capacity, low heart rate recovery (HRR), and not achieving target heart rate were independently associated with increased all-cause and cardiovascular mortality. There was no increased cardiovascular death risk for exercise-induced ST-segment depression (age-adjusted hazard ratio, 1.02; 95% confidence interval [CI], 0.57-1.80; P =.96). The age-adjusted hazard ratio for cardiovascular death for every metabolic equivalent (MET) decrement in exercise capacity was 1.20 (95% CI, 1.18-1.30; P<.001); for every 10 beats per minute decrement in HRR, the hazard ratio was 1.36 (95% CI, 1.19-1.55; P<.001). After adjusting for multiple other risk factors, women who were below the median for both exercise capacity and HRR had a 3.5-fold increased risk of cardiovascular death (95% CI, 1.57-7.86; P =.002) compared with those above the median for both variables. Among women with low risk Framingham scores, those with below median levels of both exercise capacity and HRR had significantly increased risk compared with women who had above median levels of these 2 exercise variables, 44.5 and 3.5 cardiovascular deaths per 10 000 person-years, respectively (hazard ratio for cardiovascular death, 12.93; 95% CI, 5.62-29.73; P<.001). The prognostic value of exercise testing in asymptomatic women derives not from electrocardiographic ischemia but from fitness-related variables.

Effects of a Community-Based, Post-Rehabilitation Exercise Program in COPD: Protocol for a Randomized Controlled Trial With Embedded Process Evaluation.

PubMed

Desveaux, Laura; Beauchamp, Marla K; Lee, Annemarie; Ivers, Noah; Goldstein, Roger; Brooks, Dina

2016-05-11

This manuscript (1) outlines the intervention, (2) describes how its effectiveness is being evaluated in a pragmatic randomized controlled trial, and (3) summarizes the embedded process evaluation aiming to understand key barriers and facilitators for implementation in new environments. Participating centers refer eligible individuals with COPD following discharge from their local PR program. Consenting patients are assigned to a year-long community exercise program or usual care using block randomization and stratifying for supplemental oxygen use. Patients in the intervention arm are asked to attend an exercise session at least twice per week at their local community facility where their progress is supervised by a case manager. Each exercise session includes a component of aerobic exercise, and activities designed to optimize balance, flexibility, and strength. All study participants will have access to routine follow-up appointments with their respiratory physician, and additional health care providers as part of their usual care. Assessments will be completed at baseline (post-PR), 6, and 12 months, and include measures of functional exercise capacity, quality of life, self-efficacy, and health care usage. Intervention effectiveness will be assessed by comparing functional exercise capacity between intervention and control groups. A mixed-methods process evaluation will be conducted to better understand intervention implementation, guided by Normalization Process Theory and the Consolidated Framework for Implementation Research. Based on results from our pilot work, we anticipate a maintenance of exercise capacity and improved health-related quality of life in the intervention group, compared with a decline in exercise capacity in the usual care group. Findings from this study will improve our understanding of the effectiveness of community-based exercise programs for maintaining benefits following PR in patients with COPD and provide information on how best to implement them. If effective, the intervention represents an opportunity to transition patients from institutionally-based rehabilitative management to community-based care. The results of the process evaluation will contribute to the science of translating evidence-based programs into regular practice.

Resistance training program for fatigue management in the workplace: exercise protocol in a cluster randomized controlled trial.

PubMed

Santos, Hélio Gustavo; Chiavegato, Luciana Dias; Valentim, Daniela Pereira; da Silva, Patricia Rodrigues; Padula, Rosimeire Simprini

2016-12-22

Fatigue is a multifactorial condition that leads to disease and loss in production, and it affects a large number of workers worldwide. This study aims to demonstrate a resistance exercise protocol that individuals will perform during the work schedule, and to evaluate the effectiveness of this exercises program for fatigue control. This is a cluster randomized controlled trial with two arms and is assessor blinded. A total of 352 workers of both sexes, aged 18-65 years, from a medium-sized dairy plant were enrolled in this study. Participants will be recruited from 13 production sectors according to the eligibility criteria and will be randomized by clusters to either the Progressive Resistance Exercise (PRE) intervention group or the Compensatory Workplace Exercise (CWE) comparative group. A resistance exercise program will be implemented for both groups. The groups will receive instructions on self-management, breaks, adjustments to workstations, and the benefits of physical exercise. The PRE group will perform resistance exercises with gradual loads in an exercise room, and the CWE group will perform exercise at their workstations using elastic bands. The exercise sessions will be held 3 times a week for 20 min. The primary outcome measures will be symptoms of physical and mental fatigue, and muscular fatigue based on a one-repetition maximum (1RM). The secondary outcome measures will be level of physical activity, musculoskeletal symptoms, physical condition, perceived exposure, and productivity. The workers will be assessed at baseline and after a 4-month program. A linear mixed model will be applied on an intention-to-treat basis. This intervention is expected to reduce symptoms of fatigue in the workers. The exercise program is indicating in the workplace, although there are few studies describing the effects of exercise on the control of fatigue in the workplace. Emphasis will be placed on adherence to the program, which may result in significant and clinically important reductions in fatigue. It is also expected that the findings of this study will contribute significantly to the decision-making capacity of professionals working in the field of occupational health. U.S. National Institutes of Health, ClinicalTrials.gov Identifier: NCT02172053 . Date registered 19 June 2014.

Ventilation and Speech Characteristics during Submaximal Aerobic Exercise

ERIC Educational Resources Information Center

Baker, Susan E.; Hipp, Jenny; Alessio, Helaine

2008-01-01

Purpose: This study examined alterations in ventilation and speech characteristics as well as perceived dyspnea during submaximal aerobic exercise tasks. Method: Twelve healthy participants completed aerobic exercise-only and simultaneous speaking and aerobic exercise tasks at 50% and 75% of their maximum oxygen consumption (VO[subscript 2] max).…

"EXHALE": exercise as a strategy for rehabilitation in advanced stage lung cancer patients: a randomized clinical trial comparing the effects of 12 weeks supervised exercise intervention versus usual care for advanced stage lung cancer patients.

PubMed

Quist, Morten; Langer, Seppo W; Rørth, Mikael; Christensen, Karl Bang; Adamsen, Lis

2013-10-14

Lung cancer is the leading cause of cancer death in North America and Western Europe. Patients with lung cancer in general have reduced physical capacity, functional capacity, poor quality of life and increased levels of anxiety and depression. Intervention studies indicate that physical training can address these issues. However, there is a lack of decisive evidence regarding the effect of physical exercise in patients with advanced lung cancer. The aim of this study is to evaluate the effects of a twelve weeks, twice weekly program consisting of: supervised, structured training in a group of advanced lung cancer patients (cardiovascular and strength training, relaxation). A randomized controlled trial will test the effects of the exercise intervention in 216 patients with advanced lung cancer (non-small cell lung cancer (NSCLC) stage IIIb-IV and small cell lung cancer (SCLC) extensive disease (ED)). Primary outcome is maximal oxygen uptake (VO₂peak). Secondary outcomes are muscle strength (1RM), functional capacity (6MWD), lung capacity (Fev1) and patient reported outcome (including anxiety, depression (HADS) and quality of life (HRQOL)). The present randomized controlled study will provide data on the effectiveness of a supervised exercise intervention in patients receiving systemic therapy for advanced lung cancer. It is hoped that the intervention can improve physical capacity and functional level, during rehabilitation of cancer patients with complex symptom burden and help them to maintain independent function for as long as possible. http://ClinicalTrials.gov, NCT01881906.

High-speed resistance training is more effective than low-speed resistance training to increase functional capacity and muscle performance in older women.

PubMed

Ramírez-Campillo, Rodrigo; Castillo, Angélica; de la Fuente, Carlos I; Campos-Jara, Christian; Andrade, David C; Álvarez, Cristian; Martínez, Cristian; Castro-Sepúlveda, Mauricio; Pereira, Ana; Marques, Mário C; Izquierdo, Mikel

2014-10-01

To examine the effects of 12 weeks of high-speed resistance training (RT) versus low-speed RT on muscle strength [one repetition of maximum leg-press (1RMLP) and bench-press (1RMBP), plus dominant (HGd) and non-dominant maximum isometric handgrip], power [counter-movement jump (CMJ), ball throwing (BT) and 10-m walking sprint (S10)], functional performance [8-foot up-and-go test (UG) and sit-to-stand test (STS)], and perceived quality of life in older women. 45 older women were divided into a high-speed RT group [EG, n=15, age=66.3±3.7y], a low-speed RT group [SG, n=15, age=68.7±6.4y] and a control group [CG, n=15, age=66.7±4.9y]. The SG and EG were submitted to a similar 12-week RT program [3 sets of 8 reps at 40-75% of the one-repetition maximum (1

Reduced exercise capacity in untreated adults with primary growth hormone resistance (Laron syndrome).

PubMed

Ben-Dov, Issahar; Gaides, Mark; Scheinowitz, Mickey; Wagner, Rivka; Laron, Zvi

2003-12-01

Primary IGF-I deficiency (Laron syndrome, LS) may decrease exercise capacity as a result of a lack of an IGF-I effect on heart, peripheral muscle or lung structure and/or function. Eight patients (six females) who had never received treatment with IGF-I, with mean age of 36 +/- 10 (SD) years (range 21-48), weight 47 +/- 9 kg (31-61), height 126 +/- 12 cm (112-140) and body mass index of 29 +/- 4 kg/m2 (24-34), and 12 age-matched controls, underwent lung function tests and incremental cycling to the limit of tolerance (CPX, MedGraphics). Predicted values for the patients were derived from adult equations based on height. In LS patients, lung function was near normal; vital capacity was 84 +/- 11% of expected (66-103). Peak exercise O2-uptake and the anaerobic threshold were reduced, 57 +/- 20% of predicted and 33 +/- 9% of predicted peak (P = 0.005 vs. controls), despite normal mean exercise breathing reserve. All parameters were normal in the controls. Exercise capacity in untreated adults with LS is significantly reduced. The limitation for most patients was not ventilatory but resulted either from low cardiac output and/or from dysfunction of the peripheral muscles. However, the relative contribution of each of these elements and/or the role of poor fitness needs further study.

Enhanced external counterpulsation - effect on angina pectoris, QoL and exercise capacity after 1 year.

PubMed

May, Ole; Lynggaard, Vibeke; Mortensen, Jesper C A; Malczynski, Jerzy

2015-02-01

Enhanced external counterpulsation (EECP) is a new therapy offered to patients with refractory angina pectoris (AP). To assess the effect of EECP on AP, quality of life (QoL) and exercise capacity in a design starting with a control period to avoid the influence of regression-towards-the-mean. Patients were examined two months before EECP, just before, just after, and three and 12 months after EECP. EECP was given for 1 h 5 days a week in 7 weeks. Three sets of pneumatic cuffs were mounted on the lower extremities and inflated sequentially in diastole to 260 mm Hg. 50 patients were included (male 72%, mean age: 62.5 years). Mean daily AP attacks were reduced during EECP from 2.7 to 0.9 (p < 0.005) and the Canadian Cardiovascular Society classification was reduced by at least 1 class in 82% just after EECP, 79% 3 months and 76% 12 months after EECP (p < 0.0002). Generic (SF36) and disease-specific QoL (Seattle AP questionnaire) improved just after, 3 and 12 months after compared with that before EECP. There was a significant improvement in exercise capacity and exercise-induced chest pain just after, three and 12 months after EECP (p < 0.02). No change was detected during the control period. EECP improves generic and disease-specific QoL, angina intensity and exercise capacity in at least 12 months.

33 CFR 155.5060 - Exercises.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Exercises. 155.5060 Section 155... § 155.5060 Exercises. (a) For nontank vessels with an oil capacity of 250 barrels or greater— (1) A... exercises as necessary to ensure that the VRP will function in an emergency. Vessel owners or operators must...

Mitochondria-specific antioxidant supplementation does not influence endurance exercise training-induced adaptations in circulating angiogenic cells, skeletal muscle oxidative capacity or maximal oxygen uptake.

PubMed

Shill, Daniel D; Southern, W Michael; Willingham, T Bradley; Lansford, Kasey A; McCully, Kevin K; Jenkins, Nathan T

2016-12-01

Reducing excessive oxidative stress, through chronic exercise or antioxidants, can decrease the negative effects induced by excessive amounts of oxidative stress. Transient increases in oxidative stress produced during acute exercise facilitate beneficial vascular training adaptations, but the effects of non-specific antioxidants on exercise training-induced vascular adaptations remain elusive. Circulating angiogenic cells (CACs) are an exercise-inducible subset of white blood cells that maintain vascular integrity. We investigated whether mitochondria-specific antioxidant (MitoQ) supplementation would affect the response to 3 weeks of endurance exercise training in CACs, muscle mitochondrial capacity and maximal oxygen uptake in young healthy men. We show that endurance exercise training increases multiple CAC types, an adaptation that is not altered by MitoQ supplementation. Additionally, MitoQ does not affect skeletal muscle or whole-body aerobic adaptations to exercise training. These results indicate that MitoQ supplementation neither enhances nor attenuates endurance training adaptations in young healthy men. Antioxidants have been shown to improve endothelial function and cardiovascular outcomes. However, the effects of antioxidants on exercise training-induced vascular adaptations remain elusive. General acting antioxidants combined with exercise have not impacted circulating angiogenic cells (CACs). We investigated whether mitochondria-specific antioxidant (MitoQ) supplementation would affect the response to 3 weeks of endurance exercise training on CD3 + , CD3 + /CD31 + , CD14 + /CD31 + , CD31 + , CD34 + /VEGFR2 + and CD62E + peripheral blood mononuclear cells (PBMCs), muscle mitochondrial capacity, and maximal oxygen uptake (VO2 max ) in healthy men aged 22.1 ± 0.7 years, with a body mass index of 26.9 ± 0.9 kg m -2 , and 24.8 ± 1.3% body fat. Analysis of main effects revealed that training induced 33, 105 and 285% increases in CD14 + /CD31 + , CD62E + and CD34 + /VEGFR2 + CACs, respectively, and reduced CD3 + /CD31 - PBMCs by 14%. There was no effect of MitoQ on CAC levels. Also independent of MitoQ supplementation, exercise training significantly increased quadriceps muscle mitochondrial capacity by 24% and VO2 max by roughly 7%. In conclusion, endurance exercise training induced increases in multiple CAC types, and this adaptation is not modified by MitoQ supplementation. Furthermore, we demonstrate that a mitochondrial-targeted antioxidant does not influence skeletal muscle or whole-body aerobic adaptations to exercise training. © 2016 The Authors. The Journal of Physiology © 2016 The Physiological Society.

Exercise training improves exercise capacity in adult patients with a systemic right ventricle: a randomized clinical trial.

PubMed

Winter, Michiel M; van der Bom, Teun; de Vries, Leonie C S; Balducci, Anna; Bouma, Berto J; Pieper, Petronella G; van Dijk, Arie P J; van der Plas, Mart N; Picchio, Fernando M; Mulder, Barbara J M

2012-06-01

To assess whether exercise training in adult patients with a systemic right ventricle (RV) improves exercise capacity and quality of life and lowers serum N-terminal prohormone brain natriuretic peptide (NT-proBNP) levels. Multi-centre parallel randomized controlled trial. Patients with a systemic RV due to congenitally or surgically corrected transposition of the great arteries. Fifty-four adult patients with a systemic RV, were randomized using unmarked opaque envelopes to an intervention group (n = 28) with three training sessions per week for 10 consecutive weeks, and a control group (n = 26). Randomization was stratified by participating centre. At baseline, and follow-up, we determined maximal exercise capacity (V'O(2peak)), serum NT-proBNP levels, and quality of life by means of the SF-36, and the TAAQOL Congenital Heart Disease questionnaires. The final analysis was performed by linear regression, taking into account the stratified randomization. Forty-six patients were analysed (male 50%, age 32 ± 11 years, intervention group n = 24, control group n = 22). Analysis at 10 weeks showed a significant difference in V'O(2peak) (3.4 mL/kg/min, 95% CI: 0.2 to 6.7; P = 0.04) and resting systolic blood pressure (-7.6 mmHg, 95% CI: -14.0 to -1.3; P = 0.03) in favour of the exercise group. No significant changes were found in serum NT-proBNP levels or quality of life in the intervention group or in the control group nor between groups. None of the patients in the intervention group had to discontinue the training programme due to adverse events. In adult patients with a systemic RV exercise training improve exercise capacity. We recommend to revise restrictive guidelines, and to encourage patients to become physically active. ( The study was registered at http://trialregister.nl. Identifier: NTR1909.).

Effects of an Exercise Programme on Functional Capacity, Body Composition and Risk of Falls in Patients with Cirrhosis: A Randomized Clinical Trial

PubMed Central

Román, Eva; García-Galcerán, Cristina; Torrades, Teresa; Herrera, Silvia; Marín, Ana; Doñate, Maite; Alvarado-Tapias, Edilmar; Malouf, Jorge; Nácher, Laura; Serra-Grima, Ricard; Guarner, Carlos; Soriano, German

2016-01-01

Patients with cirrhosis often have functional limitations, decreased muscle mass, and a high risk of falls. These variables could improve with exercise. The aim was to study the effects of moderate exercise on functional capacity, body composition and risk of falls in patients with cirrhosis. Twenty-three cirrhotic patients were randomized to an exercise programme (n = 14) or to a relaxation programme (n = 9). Both programmes consisted of a one-hour session 3 days a week for 12 weeks. At the beginning and end of the study, we measured functional capacity using the cardiopulmonary exercise test, evaluated body composition using anthropometry and dual energy X-ray absorptiometry, and estimated risk of falls using the Timed Up&Go test. In the exercise group, cardiopulmonary exercise test showed an increase in total effort time (p<0.001) and ventilatory anaerobic threshold time (p = 0.009). Upper thigh circumference increased and mid-arm and mid-thigh skinfold thickness decreased. Dual energy X-ray absorptiometry showed a decrease in fat body mass (-0.94 kg, 95%CI -0.48 to -1.41, p = 0.003) and an increase in lean body mass (1.05 kg, 95%CI 0.27 to 1.82, p = 0.01), lean appendicular mass (0.38 kg, 95%CI 0.06 to 0.69, p = 0.03) and lean leg mass (0.34 kg, 95%CI 0.10 to 0.57, p = 0.02). The Timed Up&Go test decreased at the end of the study compared to baseline (p = 0.02). No changes were observed in the relaxation group. We conclude that a moderate exercise programme in patients with cirrhosis improves functional capacity, increases muscle mass, and decreases body fat and the Timed Up&Go time. Trial Registration: ClinicalTrials.gov NCT01447537 PMID:27011355

An overview of the issues: physiological effects of bed rest and restricted physical activity

NASA Technical Reports Server (NTRS)

Convertino, V. A.; Bloomfield, S. A.; Greenleaf, J. E.

1997-01-01

Reduction of exercise capacity with confinement to bed rest is well recognized. Underlying physiological mechanisms include dramatic reductions in maximal stroke volume, cardiac output, and oxygen uptake. However, bed rest by itself does not appear to contribute to cardiac dysfunction. Increased muscle fatigue is associated with reduced muscle blood flow, red cell volume, capillarization and oxidative enzymes. Loss of muscle mass and bone density may be reflected by reduced muscle strength and higher risk for injury to bones and joints. The resultant deconditioning caused by bed rest can be independent of the primary disease and physically debilitating in patients who attempt to reambulate to normal active living and working. A challenge to clinicians and health care specialists has been the identification of appropriate and effective methods to restore physical capacity of patients during or after restricted physical activity associated with prolonged bed rest. The examination of physiological responses to bed rest deconditioning and exercise training in healthy subjects has provided significant information to develop effective rehabilitation treatments. The successful application of acute exercise to enhance orthostatic stability, daily endurance exercise to maintain aerobic capacity, or specific resistance exercises to maintain musculoskeletal integrity rather than the use of surgical, pharmacological, and other medical treatments for clinical conditions has been enhanced by investigation and understanding of underlying mechanisms that distinguish physical deconditioning from the disease. This symposium presents an overview of cardiovascular and musculoskeletal deconditioning associated with reduced physical work capacity following prolonged bed rest and exercise training regimens that have proven successful in ameliorating or reversing these adverse effects.

Factors affecting the response to exercise in patients with severe pulmonary arterial hypertension.

PubMed

Flox-Camacho, Angela; Escribano-Subías, Pilar; Jiménez-López Guarch, Carmen; Fernández-Vaquero, Almudena; Martín-Ríos, Dolores; de la Calzada-Campo, Carlos Sáenz

2011-01-01

Ergospirometry objectively quantifies exercise capacity. Up until now, the response to exercise evaluated by ergospirometry in patients with pulmonary arterial hypertension has only been described in recently diagnosed.patients. Our aim is to describe the response to exercise in patients with severe pulmonary arterial hypertension under specific treatment and define which parameters determine their exercise capacity. A cross-sectional study was performed on 80 patients, 57 women, aged 45 (14), with severe pulmonary arterial hypertension (48 idiopathic, 14 related to toxic rapeseed oil, 13 to connective tissue disease, 5 to human immunodeficiency virus), mean pulmonary pressure at diagnosis 61(15)mmHg and after 49(33) months under treatment since diagnosis. Biomarkers were measured and echocardiography and ergospirometry were performed the same day. Our patients, under specific treatment, showed the typical behaviour of patients with pulmonary arterial hypertension with less limitation of both aerobic capacity and ventilatory efficiency. Being male (p=0.004), high ventilatory equivalent for carbon dioxide at anaerobic threshold (p<0.001) or biomarkers (p=0.006) were the strongest predictors of impaired peak oxygen uptake in multivariate analysis, whereas for an impaired percentage achieved of predicted value were right ventricle diastolic diameter (p<0.001), months of treatment (p=0.01) and high ventilatory equivalent for CO(2) (p<0.001). In pulmonary arterial hypertension, right ventricle dysfunction (expressed by its dilation or high NTproBNP) and impaired ventilatory inefficiency as well as being male or a short time under treatment can be considered as determining factors of impaired exercise capacity. Copyright © 2010 SEPAR. Published by Elsevier Espana. All rights reserved.

Exercise Responses after Inactivity

NASA Technical Reports Server (NTRS)

Convertino, Victor A.

1986-01-01

The exercise response after bed rest inactivity is a reduction in the physical work capacity and is manifested by significant decreases in oxygen uptake. The magnitude of decrease in maximal oxygen intake V(dot)O2max is related to the duration of confinement and the pre-bed-rest level of aerobic fitness; these relationships are relatively independent of age and gender. The reduced exercise performance and V(dot)O2max following bed rest are associated with various physiological adaptations including reductions in blood volume, submaximal and maximal stroke volume, maximal cardiac output, sceletal muscle tone and strength, and aerobic enzyme capacities, as well as increases in venous compliance and submaximal and maximal heart rate. This reduction in physiological capacity can be partially restored by specific countermeasures that provide regular muscular activity or orhtostatic stress or both during the bed rest exposure. The understanding of these physiological and physical responses to exercise following bed rest inactivity has important implications for the solution to safety and health problems that arise in clinical medicine, aerospace medicine, sedentary living, and aging.

Prediction of Maximum Oxygen Uptake Using Both Exercise and Non-Exercise Data

ERIC Educational Resources Information Center

George, James D.; Paul, Samantha L.; Hyde, Annette; Bradshaw, Danielle I.; Vehrs, Pat R.; Hager, Ronald L.; Yanowitz, Frank G.

2009-01-01

This study sought to develop a regression model to predict maximal oxygen uptake (VO[subscript 2max]) based on submaximal treadmill exercise (EX) and non-exercise (N-EX) data involving 116 participants, ages 18-65 years. The EX data included the participants' self-selected treadmill speed (at a level grade) when exercise heart rate first reached…

Mental Fatigue and Physical and Cognitive Performance During a 2-Bout Exercise Test.

PubMed

Vrijkotte, Susan; Meeusen, Romain; Vandervaeren, Cloe; Buyse, Luk; Cutsem, Jeroen van; Pattyn, Nathalie; Roelands, Bart

2018-04-01

The 2-bout exercise protocol has been developed to diagnose nonfunctional overreaching and the "overtraining syndrome." It consists of 2 maximal exercise bouts separated by 4 hours. Mental fatigue negatively influences performance, but the effects of its occurrence during the 2-bout exercise protocol have never been investigated. The aim of this study was to examine whether mental fatigue (induced during the rest period) influences physical and cognitive performance during/after the second exercise bout of the 2-bout exercise protocol. Nine healthy, well-trained male cyclists participated in a single-blind, randomized, placebo-controlled crossover study. The intervention consisted of either 1.5-hour rest (control) or performing a computer-based Stroop task to induce mental fatigue. Cognitive (Eriksen Flanker task), physiological (lactate, maximum heart rate, and maximum wattage), and subjective data (mental fatigue-visual analog scale, Profile of Mood States, and rating of perceived exertion) were gathered. Ratings of fatigue, tension, and mental fatigue were affected in the mental fatigue condition (P < .05). Neither physiological nor cognitive differences were found between conditions. Ratings of mental fatigue were already affected after the first maximum exercise test (P < .05). Neither physical nor cognitive performance was affected by mental fatigue, but subjective ratings did reveal significant differences. It is recommended to exclude mentally challenging tasks during the 2-bout exercise protocol rest period to ascertain unaffected subjective test results. This study should be repeated in athletes diagnosed with nonfunctional overreaching/overtraining syndrome.

Exercise physiology, testing, and training in patients supported by a left ventricular assist device.

PubMed

Loyaga-Rendon, Renzo Y; Plaisance, Eric P; Arena, Ross; Shah, Keyur

2015-08-01

The left ventricular assist device (LVAD) is an accepted treatment alternative for the management of end-stage heart failure. As we move toward implantation of LVADs in less severe cases of HF, scrutiny of functional capacity and quality of life becomes more important. Patients demonstrate improvements in exercise capacity after LVAD implantation, but the effect is less than predicted. Exercise training produces multiple beneficial effects in heart failure patients, which would be expected to improve quality of life. In this review, we describe factors that are thought to participate in the persistent exercise impairment in LVAD-supported patients, summarize current knowledge about the effect of exercise training in LVAD-supported patients, and suggest areas for future research. Copyright © 2015 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.

The role of exercise in modifying outcomes for people with multiple sclerosis: a randomized trial

PubMed Central

2013-01-01

Background Despite the commonly known benefits of exercise and physical activity evidence shows that persons Multiple Sclerosis (MS) are relatively inactive yet physical activity may be even more important in a population facing functional deterioration. No exercise is effective if it is not done and people with MS face unique barriers to exercise engagement which need to be overcome. We have developed and pilot tested a Multiple Sclerosis Tailored Exercise Program (MSTEP) and it is ready to be tested against general guidelines for superiority and ultimately for its impact on MS relevant outcomes. The primary research question is to what extent does an MS Tailored Exercise Program (MSTEP) result in greater improvements in exercise capacity and related outcomes over a one year period in comparison to a program based on general guidelines for exercise among people with MS who are sedentary and wish to engage in exercise as part of MS self-management. Methods/Design The proposed study is an assessor-blind, parallel-group, randomized controlled trial (RCT). The duration of the intervention will be one year with follow-up to year two. The targeted outcomes are exercise capacity, functional ambulation, strength, and components of quality of life including frequency and intensity of fatigue symptoms, mood, global physical function, health perception, and objective measures of activity level. Logistic regression will be used to test the main hypothesis related to the superiority of the MSTEP program based on a greater proportion of people making a clinically relevant gain in exercise capacity at 1 year and at 2 years, using an intention-to-treat approach. Sample size will be 240 (120 per group). Discussion The MS community is clearly looking for interventions to help alleviate the disabling sequelae of MS and promote health. Exercise is a well-known intervention which has known benefits to all, yet few exercise regularly. For people with MS, the role of exercise in MS management needs to be rigorously assessed to inform people as to how best to use exercise to reduce disability and promote health. Trial registration Clinical Trials.gov: NCT01611987 PMID:23809312

Influences of chemical sympathectomy and simulated weightlessness on male and female rats

NASA Technical Reports Server (NTRS)

Woodman, Christopher R.; Stump, Craig S.; Stump, Jane A.; Sebastian, Lisa A.; Rahman, Z.; Tipton, Charles M.

1991-01-01

Consideration is given to a study aimed at determining whether the sympathetic nervous system is associated with the changes in maximum oxygen consumption (VO2max), run time, and mechanical efficiency observed during simulated weightlessness in male and female rats. Female and male rats were compared for food consumption, body mass, and body composition in conditions of simulated weightlessness to provide an insight into how these parameters may influence aerobic capacity and exercise performance. It is concluded that chemical sympathectomy and/or a weight-bearing stimulus will attenuate the loss in VO2max associated with simulated weightlessness in rats despite similar changes in body mass and composition. It is noted that the mechanisms remain unclear at this time.

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.

Aerobic exercise before diving reduces venous gas bubble formation in humans

PubMed Central

Dujić, Željko; Duplančic, Darko; Marinovic-Terzić, Ivana; Baković, Darija; Ivančev, Vladimir; Valic, Zoran; Eterović, Davor; Petri, Nadan M; Wisløff, Ulrik; Brubakk, Alf O

2004-01-01

We have previously shown in a rat model that a single bout of high-intensity aerobic exercise 20h before a simulated dive reduces bubble formation and after the dive protects from lethal decompression sickness. The present study investigated the importance of these findings in man. Twelve healthy male divers were compressed in a hyperbaric chamber to 280kPa at a rate of 100kPamin−1 breathing air and remaining at pressure for 80min. The ascent rate was 9mmin−1 with a 7min stop at 130kPa. Each diver underwent two randomly assigned simulated dives, with or without preceding exercise. A single interval exercise performed 24h before the dive consisted of treadmill running at 90% of maximum heart rate for 3min, followed by exercise at 50% of maximum heart rate for 2min; this was repeated eight times for a total exercise period of 40min. Venous gas bubbles were monitored with an ultrasonic scanner every 20min for 80min after reaching surface pressure. The study demonstrated that a single bout of strenuous exercise 24h before a dive to 18 m of seawater significantly reduced the average number of bubbles in the pulmonary artery from 0.98 to 0.22 bubbles cm−2(P= 0.006) compared to dives without preceding exercise. The maximum bubble grade was decreased from 3 to 1.5 (P= 0.002) by pre-dive exercise, thereby increasing safety. This is the first report to indicate that pre-dive exercise may form the basis for a new way of preventing serious decompression sickness. PMID:14755001

Cardiopulmonary functional capacity and the role of exercise in improving maximal oxygen consumption in women with PCOS.

PubMed

Lenarcik, Agnieszka; Bidzińska-Speichert, Bozena

2010-01-01

Polycystic ovary syndrome (PCOS) is one of the most common reproductive disorder in premenopausal women and is frequently accompanied by the presence of cardiovascular risk factors. It has also been recognized that PCOS women are characterized by cardiopulmonary impairment. Reduced cardiopulmonary functional capacity and the autonomic dysfunction associated with abnormal heart rate recovery might be responsible for the increased cardiovascular risk in patients with PCOS. Exercise training has beneficial effects on cardiopulmonary functional capacity and reduces the risk of cardiovascular disease in PCOS women.

77 FR 15094 - Sawatt Hydroelectric, LLC; Notice of Application for Amendment of Exemption and Soliciting...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-14

... maximum hydraulic capacity of 331 cubic feet per second (cfs), to two generating units with a total installed capacity of 321 kW and a maximum hydraulic capacity of 333 cfs. The two units are: One existing unit rated at 225 kW with a maximum hydraulic capacity of 233 cfs and one proposed unit to be installed...

The 'Critical Power' Concept: Applications to Sports Performance with a Focus on Intermittent High-Intensity Exercise.

PubMed

Jones, Andrew M; Vanhatalo, Anni

2017-03-01

The curvilinear relationship between power output and the time for which it can be sustained is a fundamental and well-known feature of high-intensity exercise performance. This relationship 'levels off' at a 'critical power' (CP) that separates power outputs that can be sustained with stable values of, for example, muscle phosphocreatine, blood lactate, and pulmonary oxygen uptake ([Formula: see text]), from power outputs where these variables change continuously with time until their respective minimum and maximum values are reached and exercise intolerance occurs. The amount of work that can be done during exercise above CP (the so-called W') is constant but may be utilized at different rates depending on the proximity of the exercise power output to CP. Traditionally, this two-parameter CP model has been employed to provide insights into physiological responses, fatigue mechanisms, and performance capacity during continuous constant power output exercise in discrete exercise intensity domains. However, many team sports (e.g., basketball, football, hockey, rugby) involve frequent changes in exercise intensity and, even in endurance sports (e.g., cycling, running), intensity may vary considerably with environmental/course conditions and pacing strategy. In recent years, the appeal of the CP concept has been broadened through its application to intermittent high-intensity exercise. With the assumptions that W' is utilized during work intervals above CP and reconstituted during recovery intervals below CP, it can be shown that performance during intermittent exercise is related to four factors: the intensity and duration of the work intervals and the intensity and duration of the recovery intervals. However, while the utilization of W' may be assumed to be linear, studies indicate that the reconstitution of W' may be curvilinear with kinetics that are highly variable between individuals. This has led to the development of a new CP model for intermittent exercise in which the balance of W' remaining ([Formula: see text]) may be calculated with greater accuracy. Field trials of athletes performing stochastic exercise indicate that this [Formula: see text] model can accurately predict the time at which W' tends to zero and exhaustion is imminent. The [Formula: see text] model potentially has important applications in the real-time monitoring of athlete fatigue progression in endurance and team sports, which may inform tactics and influence pacing strategy.

Dialysis exercise team: the way to sustain exercise programs in hemodialysis patients.

PubMed

Capitanini, Alessandro; Lange, Sara; D'Alessandro, Claudia; Salotti, Emilio; Tavolaro, Alba; Baronti, Maria E; Giannese, Domenico; Cupisti, Adamasco

2014-01-01

Patients affected by end-stage renal disease (ESRD) show quite lower physical activity and exercise capacity when compared to healthy individuals. In addition, a sedentary lifestyle is favoured by lack of a specific counseling on exercise implementation in the nephrology care setting. Increasing physical activity level should represent a goal for every dialysis patient care management. Three crucial elements of clinical care may contribute to sustain a hemodialysis exercise program: a) involvement of exercise professionals, b) real commitment of nephrologists and dialysis professionals, c) individual patient adaptation of the exercise program. Dialysis staff have a crucial role to encourage and assist patients during intra-dialysis exercise, but other professionals should be included in the ideal "exercise team" for dialysis patients. Evaluation of general condition, comorbidities (especially cardiovascular), nutritional status and physical exercise capacity are mandatory to propose an exercise program, in either extra-dialysis or intra-dialysis setting. To this aim, nephrologist should lead a team of specialists and professionals including cardiologist, physiotherapist, exercise physiologist, renal dietician and nurse. In this scenario, dialysis nurses play a pivotal role since they guarantee a constant and direct approach. Unfortunately dialysis staff may often lack of information and formation about exercise management while they take care patients during the dialysis session. Building an effective exercise team, promoting the culture of exercise and increasing physical activity levels lead to a more complete and modern clinical care management of ESRD patients. © 2014 S. Karger AG, Basel.

Analyzing Exercise Training Effect and Its Impact on Cardiorespiratory and Cardiovascular Fitness

ERIC Educational Resources Information Center

Laumakis, Paul J.; McCormack, Kevin

2014-01-01

This paper provides a statistical investigation of the impact of heart rate levels on training effect for a specific exercise regimen, including an analysis of post-exercise heart rate recovery. Results indicate optimum target values for both average and maximum heart rate during exercise in order to improve both cardiorespiratory and…

Exercise physiology with a left ventricular assist device: Analysis of heart-pump interaction with a computational simulator.

PubMed

Fresiello, Libera; Rademakers, Frank; Claus, Piet; Ferrari, Gianfranco; Di Molfetta, Arianna; Meyns, Bart

2017-01-01

Patients with a Ventricular Assist Device (VAD) are hemodynamically stable but show an impaired exercise capacity. Aim of this work is to identify and to describe the limiting factors of exercise physiology with a VAD. We searched for data concerning exercise in heart failure condition and after VAD implantation from the literature. Data were analyzed by using a cardiorespiratory simulator that worked as a collector of inputs coming from different papers. As a preliminary step the simulator was used to reproduce the evolution of hemodynamics from rest to peak exercise (ergometer cycling) in heart failure condition. Results evidence an increase of cardiac output of +2.8 l/min and a heart rate increase to 67% of the expected value. Then, we simulated the effect of a continuous-flow VAD at both rest and exercise. Total cardiac output increases of +3.0 l/min (+0.9 l/min due to the VAD and +2.1 l/min to the native ventricle). Since the left ventricle works in a non-linear portion of the diastolic stiffness line, we observed a consistent increase of pulmonary capillary wedge pressure (from 14 to 20 mmHg) for a relatively small increase of end-diastolic volume (from 182 to 189 cm3). We finally increased VAD speed during exercise to the maximum possible value and we observed a reduction of wedge pressure (-4.5 mmHg), a slight improvement of cardiac output (8.0 l/min) and a complete unloading of the native ventricle. The VAD can assure a proper hemodynamics at rest, but provides an insufficient unloading of the left ventricle and does not prevent wedge pressure from rising during exercise. Neither the VAD provides major benefits during exercise in terms of total cardiac output, which increases to a similar extend to an unassisted heart failure condition. VAD speed modulation can contribute to better unload the ventricle but the maximal flow reachable with the current devices is below the cardiac output observed in a healthy heart.

Effects of exercise training on pulmonary hemodynamics, functional capacity and inflammation in pulmonary hypertension

PubMed Central

Richter, Manuel J.; Grimminger, Jan; Krüger, Britta; Ghofrani, Hossein A.; Mooren, Frank C.; Gall, Henning; Pilat, Christian; Krüger, Karsten

2017-01-01

Pulmonary hypertension (PH) is characterized by severe exercise limitation mainly attributed to the impairment of right ventricular function resulting from a concomitant elevation of pulmonary vascular resistance and pressure. The unquestioned cornerstone in the management of patients with pulmonary arterial hypertension (PAH) is specific vasoactive medical therapy to improve pulmonary hemodynamics and strengthen right ventricular function. Nevertheless, evidence for a beneficial effect of exercise training (ET) on pulmonary hemodynamics and functional capacity in patients with PH has been growing during the past decade. Beneficial effects of ET on regulating factors, inflammation, and metabolism have also been described. Small case-control studies and randomized clinical trials in larger populations of patients with PH demonstrated substantial improvements in functional capacity after ET. These findings were accompanied by several studies that suggested an effect of ET on inflammation, although a direct link between this effect and the therapeutic benefit of ET in PH has not yet been demonstrated. On this background, the aim of the present review is to describe current concepts regarding the effects of exercise on the pulmonary circulation and pathophysiological limitations, as well as the clinical and mechanistic effects of exercise in patients with PH. PMID:28680563

Allopurinol reduces B-type natriuretic peptide concentrations and haemoglobin but does not alter exercise capacity in chronic heart failure.

PubMed

Gavin, A D; Struthers, A D

2005-06-01

To study whether the effect of allopurinol on improvement of endothelial dysfunction in chronic heart failure (CHF) translates into improved exercise capacity and to examine whether allopurinol also improves B-type natriuretic peptide (BNP), the other important prognostic marker of CHF. Randomised, double blind, placebo controlled crossover trial. Teaching hospital. 50 patients with CHF (New York Heart Association functional classes II and III) were recruited. 50 patients with CHF were randomly assigned to three months' treatment with allopurinol (300 mg/day) or placebo. At two and three months into treatment, they underwent a modified Bruce exercise protocol and a six minute walk test. Blood was taken for BNP and haemoglobin analysis. Neither exercise test was altered by allopurinol. However, plasma BNP concentrations fell significantly (p = 0.035) with allopurinol (11.9 pmol/l) versus placebo (14.4 pmol/l). Haemoglobin concentrations also fell highly significantly with allopurinol (p = 0.001). An important negative finding is that despite high hopes for it, allopurinol had no effect on exercise capacity in CHF. On the other hand, allopurinol did reduce BNP, which is the best available surrogate marker for prognosis in CHF.

Potential benefits of maximal exercise just prior to return from weightlessness

NASA Technical Reports Server (NTRS)

Convertino, Victor A.

1987-01-01

The purpose of this study was to determine whether performance of a single maximal bout of exercise during weightlessness within hours of return to earth would enhance recovery of aerobic fitness and physical work capacities under a 1G environment. Ten healthy men were subjected to a 10-d bedrest period in the 6-deg headdown position. A graded maximal supine cycle ergometer test was performed before and at the end of bedrest to simulate exercise during weightlessness. Following 3 h of resumption of the upright posture, a second maximal exercise test was performed on a treadmill to measure work capacity under conditions of 1G. Compared to before bedrest, peak oxygen consumption, V(O2), decreased by 8.7 percent and peak heart rate (HR) increased by 5.6 percent in the supine cycle test at the end of bedrest. However, there were no significant changes in peak V(O2) and peak HR in the upright treadmill test following bedrest. These data suggest that one bout of maximal leg exercise prior to return from 10 d of weightlessness may be adequate to restore preflight aerobic fitness and physical work capacity.

Mitochondria‐specific antioxidant supplementation does not influence endurance exercise training‐induced adaptations in circulating angiogenic cells, skeletal muscle oxidative capacity or maximal oxygen uptake

PubMed Central

Shill, Daniel D.; Southern, W. Michael; Willingham, T. Bradley; Lansford, Kasey A.; McCully, Kevin K.

2016-01-01

Key points Reducing excessive oxidative stress, through chronic exercise or antioxidants, can decrease the negative effects induced by excessive amounts of oxidative stress. Transient increases in oxidative stress produced during acute exercise facilitate beneficial vascular training adaptations, but the effects of non‐specific antioxidants on exercise training‐induced vascular adaptations remain elusive.Circulating angiogenic cells (CACs) are an exercise‐inducible subset of white blood cells that maintain vascular integrity.We investigated whether mitochondria‐specific antioxidant (MitoQ) supplementation would affect the response to 3 weeks of endurance exercise training in CACs, muscle mitochondrial capacity and maximal oxygen uptake in young healthy men.We show that endurance exercise training increases multiple CAC types, an adaptation that is not altered by MitoQ supplementation. Additionally, MitoQ does not affect skeletal muscle or whole‐body aerobic adaptations to exercise training.These results indicate that MitoQ supplementation neither enhances nor attenuates endurance training adaptations in young healthy men. Abstract Antioxidants have been shown to improve endothelial function and cardiovascular outcomes. However, the effects of antioxidants on exercise training‐induced vascular adaptations remain elusive. General acting antioxidants combined with exercise have not impacted circulating angiogenic cells (CACs). We investigated whether mitochondria‐specific antioxidant (MitoQ) supplementation would affect the response to 3 weeks of endurance exercise training on CD3+, CD3+/CD31+, CD14+/CD31+, CD31+, CD34+/VEGFR2+ and CD62E+ peripheral blood mononuclear cells (PBMCs), muscle mitochondrial capacity, and maximal oxygen uptake (VO2 max ) in healthy men aged 22.1 ± 0.7 years, with a body mass index of 26.9 ± 0.9 kg m–2, and 24.8 ± 1.3% body fat. Analysis of main effects revealed that training induced 33, 105 and 285% increases in CD14+/CD31+, CD62E+ and CD34+/VEGFR2+ CACs, respectively, and reduced CD3+/CD31− PBMCs by 14%. There was no effect of MitoQ on CAC levels. Also independent of MitoQ supplementation, exercise training significantly increased quadriceps muscle mitochondrial capacity by 24% and VO2 max by roughly 7%. In conclusion, endurance exercise training induced increases in multiple CAC types, and this adaptation is not modified by MitoQ supplementation. Furthermore, we demonstrate that a mitochondrial‐targeted antioxidant does not influence skeletal muscle or whole‐body aerobic adaptations to exercise training. PMID:27501153

Exercise therapy for an older patient with left ventricular assist device.

PubMed

Park, Won Hah; Seo, Yong Gon; Sung, Ji Dong

2014-06-01

A left ventricular assist device (LVAD) is a mechanical circulation support implanted for patients with end-stage heart failure. It may be used either as a bridge to cardiac transplantation or as a destination therapy. The health of a 75-year-old man with a medical history of systolic heart failure worsened. Therefore, he was recommended to have implanted a LVAD (Thoratec Corp.) as a destination therapy. After the surgery, he was enrolled in patient cardiac rehabilitation for the improvement of dyspnea and exercise capacity. In results, there is an improvement on his exercise capacity and quality of life. For the first time in Korea, we reported a benefit of exercise therapy after being implanted with a LVAD.

33 CFR 183.33 - Maximum weight capacity: Inboard and inboard-outdrive boats.

Code of Federal Regulations, 2014 CFR

2014-07-01

... and inboard-outdrive boats. 183.33 Section 183.33 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Safe Loading § 183.33 Maximum weight capacity: Inboard and inboard-outdrive boats. (a) The maximum weight capacity (W...

33 CFR 183.35 - Maximum weight capacity: Outboard boats.

Code of Federal Regulations, 2012 CFR

2012-07-01

... boats. 183.35 Section 183.35 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Safe Loading § 183.35 Maximum weight capacity: Outboard boats. (a) The maximum weight capacity marked on a boat that is designed or intended to...

33 CFR 183.33 - Maximum weight capacity: Inboard and inboard-outdrive boats.

Code of Federal Regulations, 2011 CFR

2011-07-01

... and inboard-outdrive boats. 183.33 Section 183.33 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Safe Loading § 183.33 Maximum weight capacity: Inboard and inboard-outdrive boats. (a) The maximum weight capacity (W...

33 CFR 183.33 - Maximum weight capacity: Inboard and inboard-outdrive boats.

Code of Federal Regulations, 2012 CFR

2012-07-01

... and inboard-outdrive boats. 183.33 Section 183.33 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Safe Loading § 183.33 Maximum weight capacity: Inboard and inboard-outdrive boats. (a) The maximum weight capacity (W...

33 CFR 183.35 - Maximum weight capacity: Outboard boats.

Code of Federal Regulations, 2014 CFR

2014-07-01

... boats. 183.35 Section 183.35 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Safe Loading § 183.35 Maximum weight capacity: Outboard boats. (a) The maximum weight capacity marked on a boat that is designed or intended to...

33 CFR 183.35 - Maximum weight capacity: Outboard boats.

Code of Federal Regulations, 2011 CFR

2011-07-01

... boats. 183.35 Section 183.35 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Safe Loading § 183.35 Maximum weight capacity: Outboard boats. (a) The maximum weight capacity marked on a boat that is designed or intended to...

33 CFR 183.35 - Maximum weight capacity: Outboard boats.

Code of Federal Regulations, 2010 CFR

2010-07-01

... boats. 183.35 Section 183.35 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Safe Loading § 183.35 Maximum weight capacity: Outboard boats. (a) The maximum weight capacity marked on a boat that is designed or intended to...

33 CFR 183.33 - Maximum weight capacity: Inboard and inboard-outdrive boats.

Code of Federal Regulations, 2013 CFR

2013-07-01

... and inboard-outdrive boats. 183.33 Section 183.33 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Safe Loading § 183.33 Maximum weight capacity: Inboard and inboard-outdrive boats. (a) The maximum weight capacity (W...

33 CFR 183.35 - Maximum weight capacity: Outboard boats.

Code of Federal Regulations, 2013 CFR

2013-07-01

... boats. 183.35 Section 183.35 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Safe Loading § 183.35 Maximum weight capacity: Outboard boats. (a) The maximum weight capacity marked on a boat that is designed or intended to...

Arm mechanical efficiency and arm exercise capacity are relatively preserved in chronic obstructive pulmonary disease.

PubMed

Franssen, Frits M E; Wouters, Emiel F M; Baarends, Erica M; Akkermans, Marco A; Schols, Annemie M W J

2002-10-01

Previous studies indicate that energy expenditure related to physical activity is enhanced and that mechanical efficiency of leg exercise is reduced in patients with chronic obstructive pulmonary disease (COPD). However, it is yet unclear whether an inefficient energy expenditure is also present during other activities in COPD. This study was carried out to examine arm efficiency and peak arm exercise performance relative to leg exercise in 33 (23 male) patients with COPD ((mean +/- SEM) age: 61 +/- 2 yr; FEV : 40 +/- 2% of predicted) and 20 sex- and age-matched healthy controls. Body composition, pulmonary function, resting energy expenditure (REE), and peak leg and arm exercise performance were determined. To calculate mechanical efficiency, subjects performed submaximal leg and arm ergometry at 50% of achieved peak loads. During exercise testing, metabolic and ventilatory parameters were measured. In contrast to a reduced leg mechanical efficiency in patients compared with controls (15.6 +/- 0.6% and 22.5 +/- 0.6%, respectively; < 0.001), arm mechanical efficiency was comparable in both groups (COPD: 18.3 +/- 0.9%, controls: 21.0 +/- 1.2%; NS). Arm efficiency was not related to leg efficiency, pulmonary function, work of breathing, or REE. Also, arm exercise capacity was relatively preserved in patients with COPD (ratio arm peak work rate/leg peak work rate in patients: 89% vs 53% in controls; < 0.001). Mechanical efficiency and exercise capacity of the upper and lower limbs are not homogeneously affected in COPD, with a relative preservation of the upper limbs. This may have implications for screening of exercise tolerance and prescription of training interventions in patients with COPD. Future studies need to elucidate the mechanism behind this observation.

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.

Exercise-based cardiac rehabilitation in heart transplant recipients.

PubMed

Anderson, Lindsey; Nguyen, Tricia T; Dall, Christian H; Burgess, Laura; Bridges, Charlene; Taylor, Rod S

2017-04-04

Heart transplantation is considered to be the gold standard treatment for selected patients with end-stage heart disease when medical therapy has been unable to halt progression of the underlying pathology. Evidence suggests that aerobic exercise training may be effective in reversing the pathophysiological consequences associated with cardiac denervation and prevent immunosuppression-induced adverse effects in heart transplant recipients. To determine the effectiveness and safety of exercise-based rehabilitation on the mortality, hospital admissions, adverse events, exercise capacity, health-related quality of life, return to work and costs for people after heart transplantation. We searched the Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library, MEDLINE (Ovid), Embase (Ovid), CINAHL (EBSCO) and Web of Science Core Collection (Thomson Reuters) to June 2016. We also searched two clinical trials registers and handsearched the reference lists of included studies. We included randomised controlled trials (RCTs) of parallel group, cross-over or cluster design, which compared exercise-based interventions with (i) no exercise control (ii) a different dose of exercise training (e.g. low- versus high-intensity exercise training); or (iii) an active intervention (i.e. education, psychological intervention). The study population comprised adults aged 18 years or over who had received a heart transplant. Two review authors independently screened all identified references for inclusion based on pre-specified inclusion criteria. Disagreements were resolved by consensus or by involving a third person. Two review authors extracted outcome data from the included trials and assessed their risk of bias. One review author extracted study characteristics from included studies and a second author checked them against the trial report for accuracy. We included 10 RCTs that involved a total of 300 participants whose mean age was 54.4 years. Women accounted for fewer than 25% of all study participants. Nine trials which randomised 284 participants to receive exercise-based rehabilitation (151 participants) or no exercise (133 participants) were included in the main analysis. One cross-over RCT compared high-intensity interval training with continued moderate-intensity training in 16 participants. We reported findings for all trials at their longest follow-up (median 12 weeks).Exercise-based cardiac rehabilitation increased exercise capacity (VO 2peak ) compared with no exercise control (MD 2.49 mL/kg/min, 95% CI 1.63 to 3.36; N = 284; studies = 9; moderate quality evidence). There was evidence from one trial that high-intensity interval exercise training was more effective in improving exercise capacity than continuous moderate-intensity exercise (MD 2.30 mL/kg/min, 95% CI 0.59 to 4.01; N = 16; 1 study). Four studies reported health-related quality of life (HRQoL) measured using SF-36, Profile of Quality of Life in the Chronically Ill (PLC) and the World Health Organization Quality Of Life (WHOQoL) - BREF. Due to the variation in HRQoL outcomes and methods of reporting we were unable to meta-analyse results across studies, but there was no evidence of a difference between exercise-based cardiac rehabilitation and control in 18 of 21 HRQoL domains reported, or between high and moderate intensity exercise in any of the 10 HRQoL domains reported. One adverse event was reported by one study.Exercise-based cardiac rehabilitation improves exercise capacity, but exercise was found to have no impact on health-related quality of life in the short-term (median 12 weeks follow-up), in heart transplant recipients whose health is stable.There was no evidence of statistical heterogeneity across trials for exercise capacity and no evidence of small study bias. The overall risk of bias in included studies was judged as low or unclear; more than 50% of included studies were assessed at unclear risk of bias with respect to allocation concealment, blinding of outcome assessors and declaration of conflicts of interest. Evidence quality was assessed as moderate according to GRADE criteria. We found moderate quality evidence suggesting that exercise-based cardiac rehabilitation improves exercise capacity, and that exercise has no impact on health-related quality of life in the short-term (median 12 weeks follow-up), in heart transplant recipients. Cardiac rehabilitation appears to be safe in this population, but long-term follow-up data are incomplete and further good quality and adequately-powered trials are needed to demonstrate the longer-term benefits of exercise on safety and impact on both clinical and patient-related outcomes, such as health-related quality of life, and healthcare costs.

Exercise training in older adults, what effects on muscle oxygenation? A systematic review.

PubMed

Fiogbé, Elie; de Vassimon-Barroso, Verena; de Medeiros Takahashi, Anielle Cristhine

2017-07-01

To determine the effects of different modality of exercise training programs on muscle oxygenation in older adults. Relevant articles were searched in PubMed, Web of Science, Science Direct and Scopus, using the keywords: "Aged" AND "Muscle oxygenation" AND (Exercise OR "Exercise therapy" OR "Exercise Movement Techniques" OR Hydrotherapy), without limitation concerning the publication date. To be included in the full analysis, the study had to be a randomized controlled trial in which older adults participants (mean age: 65 years at least) were submitted to an exercise-training program and muscle oxygenation assessment. The searches resulted in 1238 articles from which 7 met all the inclusion criteria. The trials involved 370 older adults (68.7±1.7years), healthy and with peripheral arterial disease. Studies included resistance and endurance exercises as well as walking sessions. Training sessions were 2-6 time per week, lasted 3-24 months and with different training intensity throughout studies. After a long-term resistance training, healthy older adults showed enhanced muscle oxygen extraction capacity, regulation of vessels and vascular endothelium function; endurance training is reported to improve microvascular blood flow and matching of oxygen delivery to oxygen utilization, muscle oxidative capacity and muscle saturation, and walking sessions results in better muscle oxygen availability and muscle oxygen extraction capacity in older adults with peripheral arterial disease. This review supports the fact that depending on the clinical status of the participants and the modality, exercise training improves different aspects of the muscle oxygenation in older adults. Copyright © 2017 Elsevier B.V. All rights reserved.

Exercise Training Reverses Extrapulmonary Impairments in Smoke-exposed Mice.

PubMed

Bowen, T Scott; Aakerøy, Lars; Eisenkolb, Sophia; Kunth, Patricia; Bakkerud, Fredrik; Wohlwend, Martin; Ormbostad, Anne Marie; Fischer, Tina; Wisloff, Ulrik; Schuler, Gerhard; Steinshamn, Sigurd; Adams, Volker; Bronstad, Eivind

2017-05-01

Cigarette smoking is the main risk factor for chronic obstructive pulmonary disease and emphysema. However, evidence on the extrapulmonary effects of smoke exposure that precede lung impairments remains unclear at present, as are data on nonpharmacological treatments such as exercise training. Three groups of mice, including control (n = 10), smoking (n = 10), and smoking with 6 wk of high-intensity interval treadmill running (n = 11), were exposed to 20 wk of fresh air or whole-body cigarette smoke. Exercise capacity (peak oxygen uptake) and lung destruction (histology) were subsequently measured, whereas the heart, peripheral endothelium (aorta), and respiratory (diaphragm) and limb (extensor digitorum longus and soleus) skeletal muscles were assessed for in vivo and in vitro function, in situ mitochondrial respiration, and molecular alterations. Smoking reduced body weight by 26% (P < 0.05) without overt airway destruction (P > 0.05). Smoking impaired exercise capacity by 15% while inducing right ventricular dysfunction by ~20%, endothelial dysfunction by ~20%, and diaphragm muscle weakness by ~15% (all P < 0.05), but these were either attenuated or reversed by exercise training (P < 0.05). Compared with controls, smoking mice had normal limb muscle and mitochondrial function (cardiac and skeletal muscle fibers); however, diaphragm measures of oxidative stress and protein degradation were increased by 111% and 65%, respectively (P < 0.05), but these were attenuated by exercise training (P < 0.05). Prolonged cigarette smoking reduced exercise capacity concomitant with functional impairments to the heart, peripheral endothelium, and respiratory muscle that preceded the development of overt emphysema. However, high-intensity exercise training was able to reverse these smoke-induced extrapulmonary impairments.

Neither Hematocrit Normalization nor Exercise Training Restores Oxygen Consumption to Normal Levels in Hemodialysis Patients

PubMed Central

Stray-Gundersen, James; Parsons, Dora Beth; Thompson, Jeffrey R.

2016-01-01

Patients treated with hemodialysis develop severely reduced functional capacity, which can be partially ameliorated by correcting anemia and through exercise training. In this study, we determined perturbations of an erythroid-stimulating agent and exercise training to examine if and where limitation to oxygen transport exists in patients on hemodialysis. Twenty-seven patients on hemodialysis completed a crossover study consisting of two exercise training phases at two hematocrit (Hct) values: 30% (anemic) and 42% (physiologic; normalized by treatment with erythroid-stimulating agent). To determine primary outcome measures of peak power and oxygen consumption (VO2) and secondary measures related to components of oxygen transport and utilization, all patients underwent numerous tests at five time points: baseline, untrained at Hct of 30%, after training at Hct of 30%, untrained at Hct of 42%, and after training at Hct of 42%. Hct normalization, exercise training, or the combination thereof significantly improved peak power and VO2 relative to values in the untrained anemic phase. Hct normalization increased peak arterial oxygen and arteriovenous oxygen difference, whereas exercise training improved cardiac output, citrate synthase activity, and peak tissue diffusing capacity. However, although the increase in arterial oxygen observed in the combination phase reached a value similar to that in healthy sedentary controls, the increase in peak arteriovenous oxygen difference did not. Muscle biopsy specimens showed markedly thickened endothelium and electron–dense interstitial deposits. In conclusion, exercise and Hct normalization had positive effects but failed to normalize exercise capacity in patients on hemodialysis. This effect may be caused by abnormalities identified within skeletal muscle. PMID:27153927

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

Using squat repetition maximum testing to determine hamstring resistance training exercise loads.

PubMed

Ebben, William P; Long, Nicholas J; Pawlowski, Zach D; Chmielewski, Lauren M; Clewien, Rustin W; Jensen, Randall L

2010-02-01

The purpose of this study was to determine whether there is a linear relationship between the squat and a variety of hamstring resistance training exercises, and whether this relationship differs on the basis of sex. This study also sought to create prediction equations for the determination of hamstring exercise load based on the squat load. Repetition maximums of the squat, as well as 4 common hamstring resistance training exercises including the seated leg curl, stiff leg dead lift, single leg dead lift, and good morning exercise, were determined for each subject. Subjects included 21 men and 13 women collegiate athletes. Data were evaluated using linear regression analysis to predict hamstring exercise loads from 6 repetition maximum squat data. Results of the analysis of all subjects indicated that squat load was a significant predictor of loads for each of the hamstring exercises. However, separate analysis of women revealed that squat load was not a significant predictor of loads for any of the hamstring exercises. Analysis of the men revealed that squat was a significant predictor of load for the seated leg curl (R = 0.58, p < 0.001), stiff leg dead lift (R = 0.82, p < 0.001), single leg stiff leg dead lift (R = 0.80, p < 0.001), and good morning (R = 0.79, p < 0.001) exercises. On the basis of the analysis of the men, the following prediction equations were devised for each exercise: (1) seated leg curl load = squat load (0.186) + 10.935 kg, (2) stiff leg deadlift load = squat load (1.133) - 86.331 kg, (3) single leg stiff leg deadlift load = squat load (0.443) - 3.425 kg, and (4) good morning load = squat load (0.961) - 105.505 kg. Thus, results from testing core exercises such as the squat can provide useful data for the assignment of loads for assistance exercises.

Iron Status in Chronic Heart Failure: Impact on Symptoms, Functional Class and Submaximal Exercise Capacity.

PubMed

Enjuanes, Cristina; Bruguera, Jordi; Grau, María; Cladellas, Mercé; Gonzalez, Gina; Meroño, Oona; Moliner-Borja, Pedro; Verdú, José M; Farré, Nuria; Comín-Colet, Josep

2016-03-01

To evaluate the effect of iron deficiency and anemia on submaximal exercise capacity in patients with chronic heart failure. We undertook a single-center cross-sectional study in a group of stable patients with chronic heart failure. At recruitment, patients provided baseline information and completed a 6-minute walk test to evaluate submaximal exercise capacity and exercise-induced symptoms. At the same time, blood samples were taken for serological evaluation. Iron deficiency was defined as ferritin < 100 ng/mL or transferrin saturation < 20% when ferritin is < 800 ng/mL. Additional markers of iron status were also measured. A total of 538 heart failure patients were eligible for inclusion, with an average age of 71 years and 33% were in New York Heart Association class III/IV. The mean distance walked in the test was 285 ± 101 meters among those with impaired iron status, vs 322 ± 113 meters (P=.002). Symptoms during the test were more frequent in iron deficiency patients (35% vs 27%; P=.028) and the most common symptom reported was fatigue. Multivariate logistic regression analyses showed that increased levels of soluble transferrin receptor indicating abnormal iron status were independently associated with advanced New York Heart Association class (P < .05). Multivariable analysis using generalized additive models, soluble transferrin receptor and ferritin index, both biomarkers measuring iron status, showed a significant, independent and linear association with submaximal exercise capacity (P=.03 for both). In contrast, hemoglobin levels were not significantly associated with 6-minute walk test distance in the multivariable analysis. In patients with chronic heart failure, iron deficiency but not anemia was associated with impaired submaximal exercise capacity and symptomatic functional limitation. Copyright © 2015 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

Assessment of Eccentric Exercise-Induced Oxidative Stress Using Oxidation-Reduction Potential Markers

PubMed Central

Stagos, Dimitrios; Goutzourelas, Nikolaos; Ntontou, Amalia-Maria; Kafantaris, Ioannis; Deli, Chariklia K.; Poulios, Athanasios; Jamurtas, Athanasios Z.; Bar-Or, David; Kouretas, Dimitrios

2015-01-01

The aim of the present study was to investigate the use of static (sORP) and capacity ORP (cORP) oxidation-reduction potential markers as measured by the RedoxSYS Diagnostic System in plasma, for assessing eccentric exercise-induced oxidative stress. Nineteen volunteers performed eccentric exercise with the knee extensors. Blood was collected before, immediately after exercise, and 24, 48, and 72 h after exercise. Moreover, common redox biomarkers were measured, which were protein carbonyls, thiobarbituric acid-reactive substances, total antioxidant capacity in plasma, and catalase activity and glutathione levels in erythrocytes. When the participants were examined as one group, there were not significant differences in any marker after exercise. However, in 11 participants there was a high increase in cORP after exercise, while in 8 participants there was a high decrease. Thus, the participants were divided in low cORP group exhibiting significant decrease in cORP after exercise and in high cORP group exhibiting significant increase. Moreover, only in the low cORP group there was a significant increase in lipid peroxidation after exercise suggesting induction of oxidative stress. The results suggested that high decreases in cORP values after exercise may indicate induction of oxidative stress by eccentric exercise, while high increases in cORP values after exercise may indicate no existence of oxidative stress. PMID:25874019

Effect of an individualised physical exercise program on lipid profile in sedentary patients with cardiovascular risk factors.

PubMed

Rubio Pérez, Francisco Javier; Franco Bonafonte, Luis; Ibarretxe Guerediaga, Daiana; Oyon Belaza, Maria Pilar; Ugarte Peyron, Paola

Physical exercise has become in an important tool in the reduction of cardiovascular risk. To evaluate the effectiveness of an unsupervised physical exercise program that on the physical condition and the lipid profile. The final sample included 49 sedentary men and women, who were non-smokers, with dyslipidaemia, overweight, and type1 obesity. The 4-month program included walking for 30-60minutes every day, and for three days a week, 30minutes of cycling at an intensity of 40-60% of maximum functional capacity, as well as isometric abdominals and static stretching. Anthropometrics, physical condition (6minute test), and the lipid profile were evaluated before and after the physical exercise program. The objective was to achieve a caloric expenditure between 1200-2000kcal/week. At the end of the program it was observed, in both sexes, that there was a decrease in total cholesterol (P<0.02), LDL cholesterol (P<0.01), VLDL cholesterol (P<0.01), and triglycerides (P<0.05), and an increase HDL cholesterol (P<0.05). There was also an increase in the distance travelled in the 6minute test of 52m in men and 39.5m in women (P<0.002), plus a decrease in the perception of fatigue on the Borg scale of 1.19 in men, and 0.96 in women (P<0.01). There were no anthropometric changes. The physical exercise improved physical condition and the lipid profile in the sample that has been studied, with 64% of participants continuing to do it. Copyright © 2017 Sociedad Española de Arteriosclerosis. Publicado por Elsevier España, S.L.U. All rights reserved.

A theory-based exercise intervention in patients with heart failure: A protocol for randomized, controlled trial

PubMed Central

Rajati, Fatemeh; Mostafavi, Firoozeh; Sharifirad, Gholamreza; Sadeghi, Masoomeh; Tavakol, Kamran; Feizi, Awat; Pashaei, Tahereh

2013-01-01

Background: Regular exercise has been associated with improved quality of life (QoL) in patients with heart failure (HF). However, less is known on the theoretical framework, depicting how educational intervention on psychological, social, and cognitive variables affects physical activity (PA). The purpose of this study is to assess the effectiveness of a social cognitive theory-based (SCT-based) exercise intervention in patients with HF. Materials and Methods: This is a randomized controlled trial, with measurements at baseline, immediately following the intervention, and at 1, 3, and 6 months follow-up. Sixty patients who are referred to the cardiac rehabilitation (CR) unit and meet the inclusion criteria will be randomly allocated to either an intervention group or a usual-care control group. Data will be collected using various methods (i.e., questionnaires, physical tests, paraclinical tests, patients’ interviews, and focus groups). The patients in the intervention group will receive eight face-to-face counseling sessions, two focus groups, and six educational sessions over a 2-month period. The intervention will include watching videos, using book and pamphlets, and sending short massage services to the participants. The primary outcome measures are PA and QoL. The secondary outcome measures will be the components of SCT, heart rate and blood pressure at rest, body mass index, left ventricular ejection fraction, exercise capacity, and maximum heart rate. Conclusion: The findings of this trial may assist with the development of a theoretical model for exercise intervention in CR. The intervention seems to be promising and has the potential to bridge the gap of the usually limited and incoherent provision of educational care in the CR setting. PMID:24379841

[Adaptation to effort in patients with chronic cardiac insufficiency; study by post-exercise Doppler echocardiography, comparative results with a control population].

PubMed

Pouillart, F; Perchet, H; Duval-Moulin, A M; Heintz, J F; Hittinger, L; Brun, P; Castaigne, A; Dubois-Randé, J L

1995-04-01

Adaptation to exercise was studied by post-exercise Doppler echocardiography in patients with chronic cardiac failure and an apparently healthy control population matched for age. This post-exercise Doppler echocardiographic method initially introduced for the detection of myocardial ischaemia has already been validated in normal subjects for the analysis of haemodynamic changes caused by exercise providing the data is recorded in the first 5 minutes following recovery in the recumbent position. Eleven patients with chronic cardiac failure in NYHA classes II or III with a mean age of 54 +/- 11 years and 6 controls (mean age: 46 +/- 9 years) were investigated. The patients had been stabilised for at least 3 months with a vasodilator and diuretic therapy: the control subjects had no medication. After bicycle ergometry performed to 70% of maximum capacity, the subjects were positioned in the left lateral recumbent position. Doppler echocardiography was then performed in the immediate recovery phase. When compared to the control population, the patients with cardiac failure had a reduced chronotropic reserve, a smaller increase in the parameters of myocardial contractility (maximal aortic velocity, maximal aortic acceleration and left ventricular fractional shortening) without an increase in left ventricular end diastolic dimensions in subjects with severe dilatation under basal conditions (left ventricular end diastolic dimension 69 +/- 3 mm). This result suggests the absence of a Frank-Starling effect. The lack of adaptation of the peripheral vascular system was demonstrated by the lack of reduction of left ventricular end systolic stress, already greatly increased at rest (176 vs 77 +/- 10 g/cm2 for patients, compared with controls; p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

[Improving physiological and psychological status in a hemodialysis patient: a nursing experience using an exercise training program].

PubMed

Liu, Yueh-Min; Yeh, Mei-Ling; Chung, Yu-Chu

2013-10-01

Exercise training during hemodialysis has been found to improve functional capacity, nutritional status, cardiovascular risk factors, depression, and well being in hemodialysis patients. This report describes a nursing experience that applied exercise training to improve activity intolerance, powerlessness, and ineffective health maintenance in a hemodialysis patient. The care period was from May 11 to July 27, 2012. The author collected information using observation, interview, physical examination, and medical record review and identified patient care problems including activity intolerance, powerlessness, and ineffective health maintenance. In addition to providing individual nursing interventions, the author designed a stationary bicycle installed at the end of the bed. The patient was asked use the bicycle to exercise 30 mins per time, three times per week for a period of 12 weeks during the patient's hemodialysis period. Before and after a 12-week of exercise training, collected the 6-minute walk test (6MWT), self-perceived improvement, and self-reported depression scales were performed prior to and after completion of the intervention. Hematological triglyceride, albumin, and hemoglobin data were collected each week. Heart rate, blood pressure, and oxygen saturation were examined prior to and after the intervention to ensure patient safety. After the 12-week intervention, the average heart rate achieved 40-60% of the maximum heart rate and the heart rate peaked between 85 and 121 bpm. Moreover, the 6MWT distance increased from 210 m to 255 m, triglyceride decreased from 622 mg/dL to 173 mg/dL, and self-perceived fatigue and depression markedly improved. This nursing experience is shared with nurses caring for patients with similar conditions.

The effects of recovery duration during high-intensity interval exercise on time spent at high rates of oxygen consumption, oxygen kinetics and blood lactate.

PubMed

Smilios, Ilias; Myrkos, Aristides; Zafeiridis, Andreas; Toubekis, Argyris; Spassis, Apostolos; Tokmakidis, Savas P

2017-03-13

The recovery duration and the work to recovery ratio are important aspects to consider when designing a high-intensity aerobic interval exercise (HIIE). This study examined the effects of recovery duration on total exercise time performed above 80, 90 and 95% of maximum oxygen consumption (VO2max) and heart rate (HRmax) during a single-bout HIIE. We also evaluated the effects on VO2 and HR kinetics, blood lactate concentration and rating of perceived exertion (RPE). Eleven moderately trained males (22.1±1 yrs.) executed, on three separate sessions, 4×4-min runs at 90% of maximal aerobic velocity (MAV) with 2-min, 3-min and 4-min of active recovery. Recovery duration did not affect the percentage of VO2max attained and the total exercise time above 80, 90 and 95% of VO2max. Exercise time above 80 and 90% of HRmax was longer with 2 and 3 min (p<0.05) as compared with the 4-min recovery. Oxygen uptake and HR amplitude were lower, mean response time slower (p<0.05), and blood lactate and RPE higher with 2-min compared to 4-min recovery (p<0.05). In conclusion, aerobic metabolism attains its upper functional limits with either 2, or 3 or 4 min of recovery during the 4×4 min HIIE; thus, all rest durations could be used for the enhancement of aerobic capacity in sports, fitness, and clinical settings. The short (2 min) compared to longer (4 min) recovery, however, evokes greater cardiovascular and metabolic stress, and activates to a greater extent anaerobic glycolysis, and hence, could be used by athletes to induce greater overall physiological challenge.

Effect of HX108-CS supplementation on exercise capacity and lactate accumulation after high-intensity exercise.

PubMed

Oh, Seung-Lyul; Chang, Hyukki; Kim, Hee-Jae; Kim, Yong-An; Kim, Dong-Sik; Ho, Seong-Hyun; Kim, Seon-Hee; Song, Wook

2013-04-15

In the present study, we determined the effects of HX108-CS (mixed extract of Schisandra chinensis and Chaenomeles sinensis) supplementation on lactate accumulation and endurance capacity. Furthermore, we examined CK (creatine kinase), LDH (lactate dehydrogenase) activity to determine whether the HX108-CS affected markers of skeletal muscle injury in vivo and in vitro. Exercise capacity was measured by an exhaustive swimming test using ICR mice divided into four groups; one group received distilled water (DW) (Control group, n = 10), and the other groups received three different dosages of HX108-CS (10, 50 and 100 mg/kg, n = 10 per group) solution in water orally. Then, for the time-dependent measurements of blood lactate, CK, and LDH, Sprague-Dawley rats were divided into two groups; one received DW (Control group, n = 10), and the other group received HX108-CS (100 mg/kg, n = 10) solution in the same way as mice. Before the exercise test, the animals were given either DW or HX108-CS for 2 weeks. High-intensity treadmill exercise was performed for 30 minutes. Blood samples were collected and analyzed during and after exercise. For the in vitro experiment, C2C12 cells were treated with HX108-CS to examine its effect on lactate production, CK, and LDH activity. Blood lactate concentration was significantly lowered immediately after treadmill exercise in HX108-CS group; however, there were no significant differences in activities of CK and LDH between HX108-CS and control during treadmill exercise and recovery phase. Furthermore, treatment with 100 mg/kg of HX108-CS led to a significant increase in the time to exhaustion in swimming test, and concurrently blood lactate concentration was significantly decreased in 50 and 100 mg/kg treated group. Moreover, our results of in vitro experiment showed that HX108-CS suppressed lactate production, CK, and LDH activity in a dose-dependent manner. These results suggest that supplementation with HX108-CS may enhance exercise capacity by lowering lactate accumulation. This may in part be related to an amelioration of skeletal muscle injury.

Caffeine stimulates voluntary wheel running in mice without increasing aerobic capacity.

PubMed

Claghorn, Gerald C; Thompson, Zoe; Wi, Kristianna; Van, Lindsay; Garland, Theodore

2017-03-01

The "energy drink" Red Bull and the "sports drink" Gatorade are often marketed to athletes, with claims that they cause performance gains. However, both are high in sugars, and also consumed by non-athletes. Few studies have addressed the effects of these drinks or their biologically active components in rodent exercise models. We used three experiments to test effects on both voluntary exercise behavior and maximal aerobic capacity in lines of mice known to differ in "athletic" traits. Mice from four replicate High Runner (HR) lines have been selectively bred for voluntary running on wheels, and run approximately three times as many revolutions per day as do mice from four non-selected Control (C) lines. HR mice also have higher endurance and maximal oxygen consumption (VO 2 max) during forced treadmill exercise. In Experiment 1, we tested the hypothesis that Gatorade or Red Bull might cause or allow mice to increase their voluntary wheel running. On days 5 and 6 of 6days of wheel access, as is used to select breeders, HR mice ran 3.3-fold more than C, and females ran 1.2-fold more than males, with no linetype by sex interaction. On day 7, mice were administered Gatorade, Red Bull or tap water. During the subsequent 19-hour period, Gatorade had no statistical effect on running, but Red Bull significantly increased distance run by both sexes and in both HR and C lines. The increase in distance run caused by Red Bull was attributable to time spent running, not an increase in mean (or maximum) speed. As previous studies have found that sucrose alone does not generally increase wheel running, we tested two other active ingredients in Red Bull, caffeine and taurine, in Experiment 2. With a similar testing protocol, caffeine alone and caffeine+taurine increased running by about half the magnitude of Red Bull. In Experiment 3, we tested the hypothesis that Red Bull or caffeine alone can increase physiological performance ability during aerobic exercise, measured as VO 2 max. In a repeated-measures design spanning 6days, females were housed with water bottles containing Red Bull, caffeine or water in a randomized order, and tested for VO 2 max twice while receiving each fluid (6 total trials). Neither Red Bull nor caffeine significantly affected either VO 2 max or a measure of trial cooperativity (rated on a scale of 1-5), but both treatments significantly reduced tiredness (rated on a scale of 1-3) scored at the end of trials for both HR and C lines. Taken together, our results suggest that caffeine increases voluntary exercise levels of mice by delaying fatigue, rather than increasing aerobic capacity. Copyright © 2017 Elsevier Inc. All rights reserved.

Increasing exercise capacity and quality of life of patients with heart failure through Wii gaming: the rationale, design and methodology of the HF-Wii study; a multicentre randomized controlled trial.

PubMed

Jaarsma, Tiny; Klompstra, Leonie; Ben Gal, Tuvia; Boyne, Josiane; Vellone, Ercole; Bäck, Maria; Dickstein, Kenneth; Fridlund, Bengt; Hoes, Arno; Piepoli, Massimo F; Chialà, Oronzo; Mårtensson, Jan; Strömberg, Anna

2015-07-01

Exercise is known to be beneficial for patients with heart failure (HF), and these patients should therefore be routinely advised to exercise and to be or to become physically active. Despite the beneficial effects of exercise such as improved functional capacity and favourable clinical outcomes, the level of daily physical activity in most patients with HF is low. Exergaming may be a promising new approach to increase the physical activity of patients with HF at home. The aim of this study is to determine the effectiveness of the structured introduction and access to a Wii game computer in patients with HF to improve exercise capacity and level of daily physical activity, to decrease healthcare resource use, and to improve self-care and health-related quality of life. A multicentre randomized controlled study with two treatment groups will include 600 patients with HF. In each centre, patients will be randomized to either motivational support only (control) or structured access to a Wii game computer (Wii). Patients in the control group will receive advice on physical activity and will be contacted by four telephone calls. Patients in the Wii group also will receive advice on physical activity along with a Wii game computer, with instructions and training. The primary endpoint will be exercise capacity at 3 months as measured by the 6 min walk test. Secondary endpoints include exercise capacity at 6 and 12 months, level of daily physical activity, muscle function, health-related quality of life, and hospitalization or death during the 12 months follow-up. The HF-Wii study is a randomized study that will evaluate the effect of exergaming in patients with HF. The findings can be useful to healthcare professionals and improve our understanding of the potential role of exergaming in the treatment and management of patients with HF. NCT01785121. © 2015 The Authors. European Journal of Heart Failure © 2015 European Society of Cardiology.

Nutrition for sports performance: issues and opportunities.

PubMed

Maughan, Ronald J; Shirreffs, Susan M

2012-02-01

Diet can significantly influence athletic performance, but recent research developments have substantially changed our understanding of sport and exercise nutrition. Athletes adopt various nutritional strategies in training and competition in the pursuit of success. The aim of training is to promote changes in the structure and function of muscle and other tissues by selective modulation of protein synthesis and breakdown in response to the training stimulus. This process is affected by the availability of essential amino acids in the post-exercise period. Athletes have been encouraged to eat diets high in carbohydrate, but low-carbohydrate diets up-regulate the capacity of muscle for fat oxidation, potentially sparing the limited carbohydrate stores. Such diets, however, do not enhance endurance performance. It is not yet known whether the increased capacity for fat oxidation that results from training in a carbohydrate-deficient state can promote loss of body fat. Preventing excessive fluid deficits will maintain exercise capacity, and ensuring adequate hydration status can also reduce subjective perception of effort. This latter effect may be important in encouraging exercise participation and promoting adherence to exercise programmes. Dietary supplement use is popular in sport, and a few supplements may improve performance in specific exercise tasks. Athletes must be cautious, however, not to contravene the doping regulations. There is an increasing recognition of the role of the brain in determining exercise performance: various nutritional strategies have been proposed, but with limited success. Nutrition strategies developed for use by athletes can also be used to achieve functional benefits in other populations.

Aerobic Capacity Following Long Duration International Spaces Station (ISS) Missions: Preliminary Results

NASA Technical Reports Server (NTRS)

Moore, Alan D.; Lee, S.M.C.; Everett, M.E.; Guined, J.R.; Knudsen, P.

2010-01-01

Maximum oxygen uptake (VO2max) is reduced immediately following space flights lasting <15 d, but has not been measured following long-duration missions. The purpose of this study is to measure VO2max and maximum work rate (WRmax) data from astronauts following ISS flights (91 to 188 d). Methods: Five astronauts [3 M, 2 F: 47+/-6 yr, 174+/-6 cm, 71.9+/-10.9 kg (mean +/- SD)] have participated in the study. Subjects performed upright cycle exercise tests to symptom-limited maximum. An initial test was done approx.270 d before flight to establish work rates for subsequent tests. Subsequent tests, conducted approx.45 d before flight and repeated on the first or second day (R+1/2) and at approx.10 d (R+10) following landing, consisted of 3 5 min stages designed to elicit 25%, 50%, and 75% of preflight VO2max, followed by 25 W(dot)/min increases. VO2, WR, and heart rate (HR) were measured using the ISS Portable Pulmonary Function System [Damec, Odense, DK]. Descriptive statistics are reported. Results: On R+1/2 mean VO2max decreased compared to preflight (Pre: 2.98+/-0.99, R+1/2: 2.63+/-0.56 L(dot)/min); 4 of 5 subjects demonstrated a loss of > 6%. WRmax also decreased on R+1/2 compared to preflight (Pre: 245+/-69, R+1/2: 210+/-45 W). On R+10, VO2max was 2.86+/-0.62 L(dot)/min, with 2 subjects still demonstrating a loss of > 6% from preflight. WRmax on R+10 was 240+/-49 W. HRmax did not change from pre to post-flight. Conclusions: These preliminary results, from the first 5 of 12 planned subjects of an ongoing ISS study, suggest that the majority of astronauts will experience a decrease in VO2max after long-duration space-flight. Interestingly, the two astronauts with the highest preflight VO2max had the greatest loss on R+1/2, and the astronaut with the lowest preflight VO2max increased by 13%. Thus, maintenance of VO2max may be more difficult in astronauts who have a high aerobic capacity, perhaps requiring more intense in-flight exercise countermeasure prescriptions.

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.

Improved Arterial–Ventricular Coupling in Metabolic Syndrome after Exercise Training

PubMed Central

Fournier, Sara B.; Donley, David A.; Bonner, Daniel E.; DeVallance, Evan; Olfert, I. Mark; Chantler, Paul D.

2014-01-01

Purpose The metabolic syndrome (MetS) is associated with a three-fold increase risk of cardiovascular (CV) morbidity and mortality, which is in part, due to a blunted CV reserve capacity, reflected by a reduced peak exercise left ventricular contractility and aerobic capacity, and a blunted peak arterial-ventricular coupling. To date, no study has examined whether aerobic exercise training in MetS can reverse the peak exercise CV dysfunction. Further, examining how exercise training alters CV function in a group of individuals with MetS prior to the development of diabetes and/or overt CVD, can provide insights into whether some of the pathophysiological changes to the CV can be delayed/reversed, lowering their CV risk. The objective of this study was to examine the effects of 8 weeks of aerobic exercise training in individuals with MetS on resting and peak exercise CV function. Methods Twenty MetS underwent either 8 weeks of aerobic exercise training (MetS-ExT; n=10) or remained sedentary (MetS-NonT; n=10) during this time period. Resting and peak exercise CV function was characterized using Doppler echocardiography and gas exchange. Results Exercise training did not alter resting left ventricular diastolic or systolic function and arterial-ventricular coupling in MetS. In contrast, at peak exercise an increase in LV contractility (40%, p<0.01), cardiac output (28%, p<0.05) and aerobic capacity (20%, p<0.01), while a reduction in vascular resistance (30%, p<0.05) and arterial-ventricular coupling (27%, p<0.01), were noted in the MetS-ExT but not the MetS-NonT group. Further, an improvement in Lifetime Risk Score was also noted in the MetS-ExT group. Conclusions These findings have clinical importance as they provide insight that some of the pathophysiological changes associated with MetS can be improved and lower the risk of CVD. PMID:24870568

Improved arterial-ventricular coupling in metabolic syndrome after exercise training: a pilot study.

PubMed

Fournier, Sara B; Donley, David A; Bonner, Daniel E; Devallance, Evan; Olfert, I Mark; Chantler, Paul D

2015-01-01

The metabolic syndrome (MetS) is associated with threefold increased risk of cardiovascular (CV) morbidity and mortality, which is partly due to a blunted CV reserve capacity, reflected by a reduced peak exercise left ventricular (LV) contractility and aerobic capacity and a blunted peak arterial-ventricular coupling. To date, no study has examined whether aerobic exercise training in MetS can reverse peak exercise CV dysfunction. Furthermore, examining how exercise training alters CV function in a group of individuals with MetS before the development of diabetes and/or overt CV disease can provide insights into whether some of the pathophysiological CV changes can be delayed/reversed, lowering their CV risk. The objective of this study was to examine the effects of 8 wk of aerobic exercise training in individuals with MetS on resting and peak exercise CV function. Twenty participants with MetS underwent either 8 wk of aerobic exercise training (MetS-ExT, n = 10) or remained sedentary (MetS-NonT, n = 10) during this period. Resting and peak exercise CV function was characterized using Doppler echocardiography and gas exchange. Exercise training did not alter resting LV diastolic or systolic function and arterial-ventricular coupling in MetS. In contrast, at peak exercise, an increase in LV contractility (40%, P < 0.01), cardiac output (28%, P < 0.05), and aerobic capacity (20%, P < 0.01), but a reduction in vascular resistance (30%, P < 0.05) and arterial-ventricular coupling (27%, P < 0.01), were noted in the MetS-ExT but not in the MetS-NonT group. Furthermore, an improvement in lifetime risk score was also noted in the MetS-ExT group. These findings have clinical importance because they provide insight that some of the pathophysiological changes associated with MetS can be improved and can lower the risk of CV disease.

Effect of dance therapy on blood pressure and exercise capacity of individuals with hypertension: A systematic review and meta-analysis.

PubMed

Conceição, Lino Sergio Rocha; Neto, Mansueto Gomes; do Amaral, Mayra Alves Soares; Martins-Filho, Paulo Ricardo Saquete; Oliveira Carvalho, Vitor

2016-10-01

Dance therapy is a less conventional modality of physical activity in cardiovascular rehabilitation. We performed a systematic review and meta-analysis to investigate the effects of dance therapy in hypertensive patients. Pubmed, Scopus, LILACS, IBECS, MEDLINE and SciELO via Virtual Health Library (Bireme) (from the earliest data available to February 2016) for controlled trials that investigated the effects of dance therapy on exercise capacity, systolic (SBP) and diastolic (DBP) blood pressure in hypertensive patients. Weighted mean differences (WMD) and 95% confidence intervals (CIs) were calculated, and heterogeneity was assessed using the I(2) test. Four studies met the eligibility criteria. Dance therapy resulted in a significant reduction in systolic blood pressure (WMD -12.01mmHg; 95% CI: -16.08, -7.94mmHg; P<0.0001) when compared with control subjects. Significant reduction in diastolic blood pressure were also found (WMD -3.38mmHg; 95% CI: -4.81, -1.94mmHg; P<0.0001), compared with control group. Exercise capacity showed a significant improvement (WMD 1.31; 95% CI: 0.16, 2.47; P<0.03). A moderate to high heterogeneity was observed in our analysis: I(2)=92% to SBP, I(2)=55% to DBP, and I(2)=82% to exercise capacity. Our meta-analysis showed a positive effect of dance therapy on exercise capacity and reduction of SBP and DBP in individuals with hypertension. However, the moderate to high heterogeneity found in our analysis limits a pragmatic recommendation of dance therapy in individuals with hypertension. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

[Effect of disease severity on upper extremity muscle strength, exercise capacity, and activities of daily living in individuals with pulmonary arterial hypertension].

PubMed

Özcan Kahraman, Buse; Özsoy, İsmail; Acar, Serap; Özpelit, Ebru; Akdeniz, Bahri; Sevinç, Can; Savcı, Sema

2017-07-01

Pulmonary arterial hypertension (PAH) is a rare disease. Although muscle strength, exercise capacity, quality of life, and activities of daily living of patients with PAH are affected, it is not known how they are affected by disease severity. The purpose of the present study was to investigate effects of disease severity on upper extremity muscle strength, exercise capacity, and performance of activities of daily living in patients with PAH. Twenty-five patients with disease severity classified according to the New York Heart Association (NYHA) as functional class II (n=14) or class III (n=11) were included in the study. Upper-extremity exercise capacity and limitations in performing activities of daily living were assessed with 6-minute pegboard and ring test (6PBRT) and the Milliken activities of daily living scale (MAS), respectively. Shoulder flexion, elbow extension, elbow flexion muscle strength, and handgrip strength were measured with dynamometer. There were no significant differences in age, gender, body mass index, or mean pulmonary artery pressure between groups (p>0.05). The 6PBRT, MAS, and elbow flexion (right) and grip strength (right and left) results were significantly lower in NYHA III group than in NYHA II group (p=0.004, p=0.002, p=0.043, p=0.002 and p=0.003, respectively). There was no significant difference in shoulder flexion, elbow flexion (left), or elbow extension between groups (p>0.05). Results suggest that upper extremity exercise capacity, elbow flexion muscle strength (right), and handgrip strength decrease and that limitations in activities of daily living grow as disease severity increases in patients with PAH. When planning rehabilitation programs, disease severity should be considered and evaluations and treatments for the upper extremities should be included.

Resistance Training Improves Muscle Function and Cardiometabolic Risks But Not Quality of Life in Older People With Type 2 Diabetes Mellitus: A Randomized Controlled Trial.

PubMed

Hsieh, Ping-Lun; Tseng, Chin-Hsiao; Tseng, Yufeng Jane; Yang, Wei-Shiung

In older people with type 2 diabetes mellitus (T2DM), the effects of aging and T2DM may compromise the function of skeletal muscle, deteriorate metabolic status, and jeopardize physical performance, aerobic capacity, and quality of life (QoL). The purpose of this study was to investigate the effects of 12 weeks of resistance training (RT) on muscle function, physical performance, cardiometabolic risks, and QoL in older people with T2DM. This study was a randomized controlled trial that employed block randomization, assessor blinding, and the intention-to-treat principle. Thirty people 65 years or older with a diagnosis of T2DM were randomly assigned to either an exercise group or a control group and were further stratified by gender. The exercise group performed 8 RT exercises in 3 sets of 8 to 12 repetitions at 75% 1-repetition maximum (1-RM) 3 times per week for 12 weeks. The control group received usual care and maintained their daily activities and lifestyle. Muscle function (1-RM and muscle oxygenation responses), physical performance (5-repetition sit-to-stand test and Timed Up and Go test), cardiometabolic risks (aerobic capacity, blood pressure, body composition, glycemic control, lipids levels, and high-sensitivity C-reactive protein levels), and QoL (Audit of Diabetes-Dependent Quality of Life 19) were assessed at baseline (week 0) and after the 12-week interventions (week 12). The 1-RM chest-press and leg-press strength and physical performance in 5-repetition sit-to-stand test were significantly improved in the exercise group compared with the controls after the interventions. The exercise group had significantly lower resting systolic blood pressure (by -12.1 mm Hg, P = 0.036) than did the controls after 12 weeks of RT, without any significant within-group change in either group after intervention. The waist circumference, fasting glucose levels, and peak diastolic blood pressure tended to favor RT over usual care after the interventions. Twelve weeks of RT increased the maximal strength in chest-press and leg-press tests, and improved 5-repetition sit-to-stand performance in older people with T2DM. Our study demonstrated that supervised, structured RT was able to promote muscle function and alleviate cardiometabolic risks in people with T2DM 65 years or older.

Impact of exercise on the functional capacity and pain of patients with knee osteoarthritis: a randomized clinical trial.

PubMed

Oliveira, Aline Mizusaki Imoto de; Peccin, Maria Stella; Silva, Kelson Nonato Gomes da; Teixeira, Lucas Emmanuel Pedro de Paiva; Trevisani, Virgínia Fernandes Moça

2012-12-01

Muscle weakness, especially of the quadriceps muscle, is one of the major musculoskeletal effects of knee osteoarthritis. Exercises are considered one of the main interventions in the conservative treatment of those patients. To assess the effectiveness of quadriceps strengthening exercises on functional capacity and symptoms related of knee osteoarthritis by use of the Timed Up and Go test (TUG), the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and the Lequesne Index. One hundred patients were randomized into two groups: 1) Exercise Group (n = 50), which included stationary bicycle, hamstrings stretching, and quadriceps strengthening; 2) Instruction Group (n = 50), which received a manual with information about knee osteoarthritis and instructions on how to deal with knee symptoms in daily activities. The manual did not include exercise instructions. The Exercise Group showed statistically significant improvement regarding the TUG test, the WOMAC aspects of pain, function, and stiffness, and the Lequesne Index, as compared with the Instruction Group. Quadriceps strengthening exercises for eight weeks are effective to improve pain, function, and stiffness in patients with knee osteoarthritis.

Statins Affect Skeletal Muscle Performance: Evidence for Disturbances in Energy Metabolism.

PubMed

Allard, Neeltje A E; Schirris, Tom J J; Verheggen, Rebecca J; Russel, Frans G M; Rodenburg, Richard J; Smeitink, Jan A M; Thompson, Paul D; Hopman, Maria T E; Timmers, Silvie

2018-01-01

Statin myopathy is linked to disturbances in mitochondrial function and exercise intolerance. To determine whether differences exist in exercise performance, muscle function, and muscle mitochondrial oxidative capacity and content between symptomatic and asymptomatic statin users, and control subjects. Cross-sectional study. Department of Physiology, Radboud University Medical Center. Long-term symptomatic and asymptomatic statin users, and control subjects (n = 10 per group). Maximal incremental cycling tests, involuntary electrically stimulated isometric quadriceps-muscle contractions, and biopsy of vastus lateralis muscle. Maximal exercise capacity, substrate use during exercise, muscle function, and mitochondrial energy metabolism. Peak oxygen uptake, maximal work load, and ventilatory efficiency were comparable between groups, but both statin groups had a depressed anaerobic threshold compared with the control group (P = 0.01). Muscle relaxation time was prolonged in both statin groups compared with the control group and rate of maximal force rise was decreased (Ptime×group < 0.001 for both measures). Mitochondrial activity of complexes II and IV was lower in symptomatic statin users than control subjects and tended to be lower for complex (C) III (CII: P = 0.03; CIII: P = 0.05; CIV: P = 0.04). Mitochondrial content tended to be lower in both statin groups than in control subjects. Statin use attenuated substrate use during maximal exercise performance, induced muscle fatigue during repeated muscle contractions, and decreased muscle mitochondrial oxidative capacity. This suggests disturbances in mitochondrial oxidative capacity occur with statin use even in patients without statin-induced muscle complaints. Copyright © 2017 Endocrine Society