Exercise-Induced Hypoalgesia After Isometric Wall Squat Exercise: A Test-Retest Reliabilty Study.

PubMed

Vaegter, Henrik Bjarke; Lyng, Kristian Damgaard; Yttereng, Fredrik Wannebo; Christensen, Mads Holst; Sørensen, Mathias Brandhøj; Graven-Nielsen, Thomas

2018-05-19

Isometric exercises decrease pressure pain sensitivity in exercising and nonexercising muscles known as exercise-induced hypoalgesia (EIH). No studies have assessed the test-retest reliability of EIH after isometric exercise. This study investigated the EIH on pressure pain thresholds (PPTs) after an isometric wall squat exercise. The relative and absolute test-retest reliability of the PPT as a test stimulus and the EIH response in exercising and nonexercising muscles were calculated. In two identical sessions, PPTs of the thigh and shoulder were assessed before and after three minutes of quiet rest and three minutes of wall squat exercise, respectively, in 35 healthy subjects. The relative test-retest reliability of PPT and EIH was determined using analysis of variance models, Person's r, and intraclass correlations (ICCs). The absolute test-retest reliability of EIH was determined based on PPT standard error of measurements and Cohen's kappa for agreement between sessions. Squat increased PPTs of exercising and nonexercising muscles by 16.8% ± 16.9% and 6.7% ± 12.9%, respectively (P < 0.001), with no significant differences between sessions. PPTs within and between sessions showed moderately strong correlations (r ≥ 0.74) and excellent (ICC ≥ 0.84) within-session (rest) and between-session test-retest reliability. EIH responses of exercising and nonexercising muscles showed no systematic errors between sessions; however, the relative test-retest reliability was low (ICCs = 0.03-0.43), and agreement in EIH responders and nonresponders between sessions was not significant (κ < 0.13, P > 0.43). A wall squat exercise increased PPTs compared with quiet rest; however, the relative and absolute reliability of the EIH response was poor. Future research is warranted to investigate the reliability of EIH in clinical pain populations.

Cardiopulmonary Response to Exercise Testing in People with Chronic Stroke: A Retrospective Study

PubMed Central

Billinger, Sandra A.; Taylor, Jordan M.; Quaney, Barbara M.

2012-01-01

Background and Purpose. This study investigated the cardiopulmonary response and safety of exercise testing at peak effort in people during the chronic stage of stroke recovery. Methods. This retrospective study examined data from 62 individuals with chronic stroke (males: 32; mean (SD); age: (12.0) yr) participating in an exercise test. Results. Both males and females had low cardiorespiratory fitness levels. No significant differences were found between gender for peak HR (P = 0.27), or VO2 peak (P = 0.29). Males demonstrated higher values for minute ventilation, tidal volume, and respiratory exchange ratio. No major adverse events were observed in the exercise tests conducted. Discussion and Conclusion. There are differences between gender that may play a role in exercise testing performance and should be considered when developing exercise programs. The low VO2 peak of this cohort of chronic stroke survivors suggests the need for participation in exercise interventions. PMID:21961083

Patterning of physiological and affective responses in older active adults during a maximal graded exercise test and self-selected exercise.

PubMed

Smith, Ashleigh E; Eston, Roger; Tempest, Gavin D; Norton, Belinda; Parfitt, Gaynor

2015-09-01

The American College of Sports Medicine has highlighted the importance of considering the physiological and affective responses to exercise when setting exercise intensity. Here, we examined the relationship between exercise intensity and physiological and affective responses in active older adults. Eighteen participants (60-74 years; 64.4 ± 3.9; 8 women) completed a maximal graded exercise test (GXT) on a treadmill. Since time to exhaustion in the GXT differed between participants, heart rate (HR), oxygen consumption (VO2), affective valence (affect) and rating of perceived exertion (RPE) were expressed relative to the individually determined ventilatory threshold (%atVT). During the GXT, VO2, HR and RPE increased linearly (all P < 0.01). Affect declined initially (but remained positive) (P = 0.03), stabilised around VT (still positive) (P > 0.05) and became negative towards the end of the test (P < 0.01). In a subsequent session, participants completed a 20-min bout of self-selected exercise (at a preferred intensity). Initially, participants chose to exercise below VT (88.2 ± 17.4 %VO2atVT); however, the intensity was adjusted to work at, or above VT (107.7 ± 19.9 %VO2atVT) after 10 min (P < 0.001), whilst affect remained positive. Together, these findings indicate that exercise around VT, whether administered during an exercise test, or self-selected by the participant, is likely to result in positive affective responses in older adults.

Clinical test responses to different orthoptic exercise regimes in typical young adults.

PubMed

Horwood, Anna; Toor, Sonia

2014-03-01

The relative efficiency of different eye exercise regimes is unclear, and in particular the influences of practice, placebo and the amount of effort required are rarely considered. This study measured conventional clinical measures following different regimes in typical young adults. A total of 156 asymptomatic young adults were directed to carry out eye exercises three times daily for 2 weeks. Exercises were directed at improving blur responses (accommodation), disparity responses (convergence), both in a naturalistic relationship, convergence in excess of accommodation, accommodation in excess of convergence, and a placebo regime. They were compared to two control groups, neither of which were given exercises, but the second of which were asked to make maximum effort during the second testing. Instruction set and participant effort were more effective than many exercises. Convergence exercises independent of accommodation were the most effective treatment, followed by accommodation exercises, and both regimes resulted in changes in both vergence and accommodation test responses. Exercises targeting convergence and accommodation working together were less effective than those where they were separated. Accommodation measures were prone to large instruction/effort effects and monocular accommodation facility was subject to large practice effects. Separating convergence and accommodation exercises seemed more effective than exercising both systems concurrently and suggests that stimulation of accommodation and convergence may act in an additive fashion to aid responses. Instruction/effort effects are large and should be carefully controlled if claims for the efficacy of any exercise regime are to be made. © 2014 The Authors Ophthalmic & Physiological Optics published by John Wiley & Sons Ltd on behalf of The College of Optometrists.

Does Physical Loading Affect The Speed and Accuracy of Tactical Decision-Making in Elite Junior Soccer Players?

PubMed

Frýbort, Pavel; Kokštejn, Jakub; Musálek, Martin; Süss, Vladimír

2016-06-01

A soccer player's capability to control and manage his behaviour in a game situation is a prerequisite, reflecting not only swift and accurate tactical decision-making, but also prompt implementation of a motor task during intermittent exercise conditions. The purpose of this study was to analyse the relationship between varying exercise intensity and the visual-motor response time and the accuracy of motor response in an offensive game situation in soccer. The participants (n = 42) were male, semi-professional, soccer players (M age 18.0 ± 0.9 years) and trained five times a week. Each player performed four different modes of exercise intensity on the treadmill (motor inactivity, aerobic, intermittent and anaerobic activity). After the end of each exercise, visual-motor response time and accuracy of motor response were assessed. Players' motion was captured by digital video camera. ANOVA indicated no significant difference (p = 0.090) in the accuracy of motor response between the four exercise intensity modes. Practical significance (Z-test = 0.31) was found in visual-motor response time between exercise with dominant involvement of aerobic metabolism, and intense intermittent exercise. A medium size effect (Z-test = 0.34) was also found in visual-motor response time between exercise with dominant involvement of aerobic metabolism and exercise with dominant involvement of anaerobic metabolism, which was confirmed by ANOVA (897.02 ± 57.46 vs. 940.95 ± 71.14; p = 0.002). The results showed that different modes of exercise intensity do not adversely affect the accuracy of motor responses; however, high-intensity exercise has a negative effect on visual-motor response time in comparison to moderate intensity exercise. Key pointsDifferent exercise intensity modes did not affect the accuracy of motor response.Anaerobic, highly intensive short-term exercise significantly decreased the visual-motor response time in comparison with aerobic exercise.Further research should focus on the assessment of VMRT from a player's real - field position view rather than a perspective view.

Homocysteine, visceral adiposity-related novel cardiometabolic risk factors, and exaggerated blood pressure response to the exercise treadmill test.

PubMed

Türker Duyuler, Pinar; Duyuler, Serkan; Demir, Mevlüt; Uçar Elalmiş, Özgül; Güray, Ümit; İleri, Mehmet

2017-12-01

Exaggerated blood pressure response to exercise is a risk factor for the development of future hypertension. In this study, we aimed to investigate the association between homocysteine, epicardial fat thickness, nonalcoholic hepatic steatosis, and exaggerated blood pressure response to exercise. We included 44 normotensive and 40 patients with exaggerated blood pressure response to exercise who have normal resting blood pressure and without a previous diagnosis of hypertension. All patients underwent treadmill exercise test and clinical, ultrasonographic, and echocardiographic evaluation. Exaggerated blood pressure response to exercise is defined as peak exercise systolic blood pressure of at least 210 mmHg in men and at least 190 mmHg in women. Homocysteine and other biochemical parameters were determined with standardized automated laboratory tests. Mean age of all participants is 47.9±8.5 years, and 36 of 84 participants were female. The frequency of diabetes mellitus in both groups was similar (P=0.250). Homeostasis model assessment index-insulin resistance had a statistically insignificant trend to be higher in a patient with exercise hypertension (P=0.058). The nonalcoholic fatty liver was more frequent in patients with exercise hypertension (13.6 vs. 47.5%, P=0.002). Epicardial fat thickness was increased in patients with exercise hypertension (5.5±1.5 vs. 7.3±1.1 mm; P=0.001). However, homocysteine levels did not significantly differ between normotensive and exercise hypertensive patients [12.3 μmol/l (5.7-16.9 μmol/l) vs. 13 μmol/l (5.9-28.3 μmol/l); P=0.883]. In our study, homocysteine levels were not associated with exaggerated blood pressure response to exercise; however, fatty liver and epicardial fat thickness as visceral adiposity-related cardiometabolic risk factors were significantly related with exaggerated blood pressure response to exercise in patients without a previous diagnosis of hypertension.

Acute Hematological and Inflammatory Responses to High-intensity Exercise Tests: Impact of Duration and Mode of Exercise.

PubMed

Minuzzi, Luciele G; Carvalho, Humberto M; Brunelli, Diego T; Rosado, Fatima; Cavaglieri, Cláudia R; Gonçalves, Carlos E; Gaspar, Joana M; Rama, Luís M; Teixeira, Ana M

2017-07-01

The purpose of this study was to investigate the hematological and inflammatory responses to 4 maximal high-intensity protocols, considering energy expenditure in each test. 9 healthy volunteers performed 4 high-intensity exercise tests of short [Wingate (WANT); Repeated-sprints (RSA)] and long durations [Continuous VO 2 test (VCONT); intermittent VO 2 test (VINT)] in a cycle-ergometer, until exhaustion. Hematological parameters and IL-6, IL-10 and creatine kinase (CK) levels were determined before (PRE), POST, 30 min, 1, 2, 12 and 24 h after the end of the protocols. Additionally, energy expenditure was determined. Leucocytes, erythrocytes and lymphocytes increased at POST and returned to PRE values at 30 min for all protocols. Lymphocytes had a second decreased at 2 h and granulocytes increased at 2 h when compared to PRE. Both variables returned to PRE values between 12-24 h into recovery. The magnitude of response for IL-6 was greater in VINT and for IL-10 in VCONT. There was no association of energy expenditure within each exercise protocol with the pattern of IL-6, IL-10 and CK responses to the exercise protocols. The present finding support that similar responses after continuous or intermittent acute protocols are observed when exercises are performed to volitional failure, regardless of the duration and mode of exercise. © Georg Thieme Verlag KG Stuttgart · New York.

Active Female Maximal and Anaerobic Threshold Cardiorespiratory Responses to Six Different Water Aerobics Exercises.

PubMed

Antunes, Amanda H; Alberton, Cristine L; Finatto, Paula; Pinto, Stephanie S; Cadore, Eduardo L; Zaffari, Paula; Kruel, Luiz F M

2015-01-01

Maximal tests conducted on land are not suitable for the prescription of aquatic exercises, which makes it difficult to optimize the intensity of water aerobics classes. The aim of the present study was to evaluate the maximal and anaerobic threshold cardiorespiratory responses to 6 water aerobics exercises. Volunteers performed 3 of the exercises in the sagittal plane and 3 in the frontal plane. Twelve active female volunteers (aged 24 ± 2 years) performed 6 maximal progressive test sessions. Throughout the exercise tests, we measured heart rate (HR) and oxygen consumption (VO2). We randomized all sessions with a minimum interval of 48 hr between each session. For statistical analysis, we used repeated-measures 1-way analysis of variance. Regarding the maximal responses, for the peak VO2, abductor hop and jumping jacks (JJ) showed significantly lower values than frontal kick and cross-country skiing (CCS; p < .001; partial η(2) = .509), while for the peak HR, JJ showed statistically significantly lower responses compared with stationary running and CCS (p < .001; partial η(2) = .401). At anaerobic threshold intensity expressed as the percentage of the maximum values, no statistically significant differences were found among exercises. Cardiorespiratory responses are directly associated with the muscle mass involved in the exercise. Thus, it is worth emphasizing the importance of performing a maximal test that is specific to the analyzed exercise so the prescription of the intensity can be safer and valid.

Changes in lipid profile variables in response to submaximal and maximal exercise in trained cyclists.

PubMed

El-Sayed, M S; Rattu, A J

1996-01-01

This study examined the effect of prolonged submaximal exercise followed by a self-paced maximal performance test on cholesterol (T-Chol), triglycerides (TG), and high-density lipoprotein cholesterol (HDLC). Nine trained male athletes cycled at 70 percent of maximal oxygen consumption for 60 min, followed by a self-paced maximal ride for 10 min. Venous blood samples were obtained at rest, at 30 and 60 min during submaximal exercise, and immediately after the performance test. Lactic acid, haematocrit (Hct), haemoglobin (Hb), T-Chol and TG were measured in the blood, while plasma was assayed for HDL-C. Plasma volume changes in response to exercise were calculated from Hct and Hb values and all lipid measurements were corrected accordingly. In order to ascertain the repeatability of lipid responses to exercise, all subjects were re-tested under identical testing conditions and experimental protocols. When data obtained during the two exercise trials were analysed by two-way ANOVA no significant differences (P > 0.05) between tests were observed. Consequently the data obtained during the two testing trials were pooled and analysed by one-way ANOVA. Blood lactic acid increased nonsignificantly (P > 0.05) during the prolonged submaximal test, but rose markedly (P <0.05) following the performance ride. Lipid variables ascertained at rest were within the normal range for healthy subjects. ANOVA showed that blood T-Chol and TG were unchanged (P > 0.05), whereas HDL-C rose significantly (P <0.05) in response to exercise. Post hoc analyses indicated that the latter change was due to a significant rise in HDL-C after the performance ride. It is concluded that apparent favourable changes in lipid profile variables occur in response to prolonged submaximal exercise followed by maximal effort, and these changes showed a good level of agreement over the two testing occasions.

Repeatability and responsiveness of exercise tests in pulmonary arterial hypertension.

PubMed

Mainguy, Vincent; Malenfant, Simon; Neyron, Anne-Sophie; Bonnet, Sébastien; Maltais, François; Saey, Didier; Provencher, Steeve

2013-08-01

Exercise tolerance in pulmonary arterial hypertension (PAH) is most commonly assessed by the 6-min walk test (6MWT). Whether endurance exercise tests are more responsive than the 6MWT remains unknown. 20 stable PAH patients (mean±sd age 53±15 years and mean pulmonary arterial pressure 44±16 mmHg) already on PAH monotherapy completed the 6MWT, the endurance shuttle walk test (ESWT) and the cycle endurance test (CET) before and after the addition of sildenafil citrate 20 mg three times daily or placebo for 28 days in a randomised double-blind crossover setting. Pre- or post-placebo tests were used to assess repeatability of each exercise test, whereas pre- or post-sildenafil citrate tests were used to assess their responsiveness. Sildenafil citrate led to placebo-corrected changes in exercise capacity of 18±25 m (p = 0.02), 58±235 s (p = 0.58) and 29±77 s (p = 0.09) for the 6MWT, the ESWT and the CET, respectively. The 6MWT was associated with a lower coefficient of variation between repeated measures (3% versus 18% versus 13%), resulting in a higher standardised response mean compared with endurance tests (0.72, 0.25 and 0.38 for the 6MWT, the ESWT and the CET, respectively). The 6MWT had the best ability to capture changes in exercise capacity when sildenafil citrate was combined with patients' baseline monotherapy, supporting its use as an outcome measure in PAH.

Central hemodynamic responses during serial exercise tests in heart failure patients using implantable hemodynamic monitors.

PubMed

Ohlsson, A; Steinhaus, D; Kjellström, B; Ryden, L; Bennett, T

2003-06-01

Exercise testing is commonly used in patients with congestive heart failure for diagnostic and prognostic purposes. Such testing may be even more valuable if invasive hemodynamics are acquired. However, this will make the test more complex and expensive and only provides information from isolated moments. We studied serial exercise tests in heart failure patients with implanted hemodynamic monitors allowing recording of central hemodynamics. Twenty-one NYHA Class II-III heart failure patients underwent maximal exercise tests and submaximal bike or 6-min hall walk tests to quantify their hemodynamic responses and to study the feasibility of conducting exercise tests in patients with such devices. Patients were followed for 2-3 years with serial exercise tests. During maximal tests (n=70), heart rate increased by 52+/-19 bpm while S(v)O(2) decreased by 35+/-10% saturation units. RV systolic and diastolic pressure increased 29+/-11 and 11+/-6 mmHg, respectively, while pulmonary artery diastolic pressure increased 21+/-8 mmHg. Submaximal bike (n=196) and hall walk tests (n=172) resulted in S(v)O(2) changes of 80 and 91% of the maximal tests, while RV pressures ranged from 72 to 79% of maximal responses. An added potential value of implantable hemodynamic monitors in heart failure patients may be to quantitatively determine the true hemodynamic profile during standard non-invasive clinical exercise tests and to compare that to hemodynamic effects of regular exercise during daily living. It would be of interest to study whether such information could improve the ability to predict changes in a patient's clinical condition and to improve tailoring patient management.

Hormonal responses in athletes: the use of a two bout exercise protocol to detect subtle differences in (over)training status.

PubMed

Meeusen, R; Piacentini, M F; Busschaert, B; Buyse, L; De Schutter, G; Stray-Gundersen, J

2004-03-01

In overtrained athletes, several signs and symptoms have been associated with the imbalance between training and recovery. However, reliable diagnostic markers for distinguishing between well-trained, overreached (OR) and overtrained (OT) athletes are lacking. A hallmark feature of overtraining syndrome (OTS) is the inability to sustain intense exercise and recover for the next training or competition session. We therefore devised a test protocol utilizing two bouts of maximal work. With this test protocol we tried to establish a difference in hormonal responses between the training status of T and OR athletes. Seven well-trained cyclists participated in this study and were tested before and after a training camp. We also present the data of one OT motocross athlete who was clinically diagnosed as overtrained. All athletes performed two maximal exercise tests separated by 4 h. Blood was analyzed for cortisol, adrenocorticotrophic hormone (ACTH), growth hormone and prolactin (PRL). Performance decreased by 6% between the first and the second exercise test in the OR group and by 11% in the OT subject. Moreover, during the second exercise test there were more marked differences between the T and OR athletes; in particular, the OT subject did not show an increase in some of the hormonal responses. PRL increased only by 14% in the OT subject's second test and there was a 7% decrease in ACTH. The two exercise approach enables us to detect subtle performance decrements that will not be identified by one exercise trigger. The hormonal responses to the second exercise test were different between the T and OR athletes (the increase in the T group was higher than in the OR that was higher than in the OT). The results of the case presentation of an overtrained athlete provide evidence of an altered and dysfunctional hypothalamic-pituitary axis response to two bouts of maximal exercise. These findings can be used to develop markers for diagnosis of OTS and to begin to address the pathologic mechanism operative in the syndrome, as well as providing an outcome measure to evaluate possible therapeutic regimes.

Sprint-based exercise and cognitive function in adolescents.

PubMed

Cooper, Simon B; Bandelow, Stephan; Nute, Maria L; Dring, Karah J; Stannard, Rebecca L; Morris, John G; Nevill, Mary E

2016-12-01

Moderate intensity exercise has been shown to enhance cognition in an adolescent population, yet the effect of high-intensity sprint-based exercise remains unknown and was therefore examined in the present study. Following ethical approval and familiarisation, 44 adolescents (12.6 ± 0.6 y) completed an exercise (E) and resting (R) trial in a counter-balanced, randomised crossover design. The exercise trial comprised of 10 × 10 s running sprints, interspersed by 50 s active recovery (walking). A battery of cognitive function tests (Stroop, Digit Symbol Substitution (DSST) and Corsi blocks tests) were completed 30 min pre-exercise, immediately post-exercise and 45 min post-exercise. Data were analysed using mixed effect models with repeated measures. Response times on the simple level of the Stroop test were significantly quicker 45 min following sprint-based exercise (R: 818 ± 33 ms, E: 772 ± 26 ms; p = 0.027) and response times on the complex level of the Stroop test were quicker immediately following the sprint-based exercise (R: 1095 ± 36 ms, E: 1043 ± 37 ms; p = 0.038), while accuracy was maintained. Sprint-based exercise had no immediate or delayed effects on the number of items recalled on the Corsi blocks test (p = 0.289) or substitutions made during the DSST (p = 0.689). The effect of high intensity sprint-based exercise on adolescents' cognitive function was dependant on the component of cognitive function examined. Executive function was enhanced following exercise, demonstrated by improved response times on the Stroop test, whilst visuo-spatial memory and general psycho-motor speed were unaffected. These data support the inclusion of high-intensity sprint-based exercise for adolescents during the school day to enhance cognition.

The measurement of peripheral blood volume reactions to tilt test by the electrical impedance technique after exercise in athletes

NASA Astrophysics Data System (ADS)

Melnikov, A. A.; Popov, S. G.; Nikolaev, D. V.; Vikulov, A. D.

2013-04-01

We have investigated the distribution of peripheral blood volumes in different regions of the body in response to the tilt-test in endurance trained athletes after aerobic exercise. Distribution of peripheral blood volumes (ml/beat) simultaneously in six regions of the body (two legs, two hands, abdomen, neck and ECG) was assessed in response to the tilt-test using the impedance method (the impedance change rate (dZ/dT). Before and after exercise session cardiac stroke (CSV) and blood volumes in legs, arms and neck were higher in athletes both in lying and standing positions. Before exercise the increase of heart rate and the decrease of a neck blood volume in response to tilting was lower (p <0.05) but the decrease of leg blood volumes was higher (p<0.001) in athletes. The reactions in arms and abdomen blood volumes were similar. Also, the neck blood volumes as percentage of CSV (%/CSV) did not change in the control but increased in athletes (p <0.05) in response to the tilt test. After (10 min recovery) the aerobic bicycle exercise (mean HR = 156±8 beat/min, duration 30 min) blood volumes in neck and arms in response to the tilting were reduced equally, but abdomen (p<0.05) and leg blood volumes (p <0.001) were lowered more significantly in athletes. The neck blood flow (%/CSV) did not change in athletes but decreased in control (p<0.01), which was offset by higher tachycardia in response to tilt-test in controls after exercise. The data demonstrate greater orthostatic tolerance in athletes both before and after exercise during fatigue which is due to effective distribution of blood flows aimed at maintaining cerebral blood flow.

Influence of work clothing on physiological responses and performance during treadmill exercise and the Wildland Firefighter Pack Test.

PubMed

Phillips, Devin B; Ehnes, Cameron M; Welch, Bradley G; Lee, Lauren N; Simin, Irina; Petersen, Stewart R

2018-04-01

This study investigated physiological responses and performance during three separate exercise challenges (Parts I, II, and III) with wildland firefighting work clothing ensemble (boots and coveralls) and a 20.4 kg backpack in four conditions: U-EX (no pack, exercise clothing); L-EX (pack, exercise clothing); U-W (no pack, work clothing); and, L-W (pack and work clothing). Part I consisted of randomly-ordered graded exercise tests, on separate days, in U-EX, L-EX and L-W conditions. Part II consisted of randomly-ordered bouts of sub-maximal treadmill exercise in the four conditions. In Part III, subjects completed, in random-order on separate days, 4.83 km Pack Tests in L-EX or L-W conditions. In Part I, peak oxygen uptake was reduced (p < .05) in L-W. In Part II, mass-specific oxygen uptake was significantly higher in both work clothing conditions. In Part III, Pack Test time was slower (p < .05) in L-W. These results demonstrate the negative impact of work clothing and load carriage on physiological responses to exercise and performance. Copyright © 2017 Elsevier Ltd. All rights reserved.

Controversies in the physiological basis of the 'anaerobic threshold' and their implications for clinical cardiopulmonary exercise testing.

PubMed

Hopker, J G; Jobson, S A; Pandit, J J

2011-02-01

This article reviews the notion of the 'anaerobic threshold' in the context of cardiopulmonary exercise testing. Primarily, this is a review of the proposed mechanisms underlying the ventilatory and lactate response to incremental exercise, which is important to the clinical interpretation of an exercise test. Since such tests are often conducted for risk stratification before major surgery, a failure to locate or justify the existence of an anaerobic threshold will have some implications for clinical practice. We also consider alternative endpoints within the exercise response that might be better used to indicate a patient's capacity to cope with the metabolic demands encountered both during and following major surgery. © 2011 The Authors. Anaesthesia © 2011 The Association of Anaesthetists of Great Britain and Ireland.

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

NASA Technical Reports Server (NTRS)

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

2015-01-01

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

Does Physical Loading Affect The Speed and Accuracy of Tactical Decision-Making in Elite Junior Soccer Players?

PubMed Central

Frýbort, Pavel; Kokštejn, Jakub; Musálek, Martin; Süss, Vladimír

2016-01-01

A soccer player’s capability to control and manage his behaviour in a game situation is a prerequisite, reflecting not only swift and accurate tactical decision-making, but also prompt implementation of a motor task during intermittent exercise conditions. The purpose of this study was to analyse the relationship between varying exercise intensity and the visual-motor response time and the accuracy of motor response in an offensive game situation in soccer. The participants (n = 42) were male, semi-professional, soccer players (M age 18.0 ± 0.9 years) and trained five times a week. Each player performed four different modes of exercise intensity on the treadmill (motor inactivity, aerobic, intermittent and anaerobic activity). After the end of each exercise, visual-motor response time and accuracy of motor response were assessed. Players’ motion was captured by digital video camera. ANOVA indicated no significant difference (p = 0.090) in the accuracy of motor response between the four exercise intensity modes. Practical significance (Z-test = 0.31) was found in visual-motor response time between exercise with dominant involvement of aerobic metabolism, and intense intermittent exercise. A medium size effect (Z-test = 0.34) was also found in visual-motor response time between exercise with dominant involvement of aerobic metabolism and exercise with dominant involvement of anaerobic metabolism, which was confirmed by ANOVA (897.02 ± 57.46 vs. 940.95 ± 71.14; p = 0.002). The results showed that different modes of exercise intensity do not adversely affect the accuracy of motor responses; however, high-intensity exercise has a negative effect on visual-motor response time in comparison to moderate intensity exercise. Key points Different exercise intensity modes did not affect the accuracy of motor response. Anaerobic, highly intensive short-term exercise significantly decreased the visual-motor response time in comparison with aerobic exercise. Further research should focus on the assessment of VMRT from a player’s real - field position view rather than a perspective view. PMID:27274671

Effects of exercise on alterations in redox homeostasis in elite male and female endurance athletes using a clinical point-of-care test.

PubMed

Lewis, Nathan A; Towey, Colin; Bruinvels, Georgie; Howatson, Glyn; Pedlar, Charles R

2016-10-01

Exercise causes alterations in redox homeostasis (ARH). Measuring ARH in elite athletes may aid in the identification of training tolerance, fatigued states, and underperformance. To the best of our knowledge, no studies have examined ARH in elite male and female distance runners at sea level. The monitoring of ARH in athletes is hindered by a lack of reliable and repeatable in-the-field testing tools and by the rapid turnaround of results. We examined the effects of various exercise intensities on ARH in healthy (non-over-reached) elite male and female endurance athletes using clinical point-of-care (POC) redox tests, referred to as the free oxygen radical test (FORT) (pro-oxidant) and the free oxygen radical defence (FORD) (antioxidant). Elite male and female endurance athletes (n = 22) completed a discontinuous incremental treadmill protocol at submaximal running speeds and a test to exhaustion. Redox measures were analyzed via blood sampling at rest, warm-up, submaximal exercise, exhaustion, and recovery. FORD was elevated above rest after submaximal and maximal exercise, and recovery (p < 0.05, d = 0.87-1.55), with only maximal exercise and recovery increasing FORT (p < 0.05, d = 0.23-0.32). Overall, a decrease in oxidative stress in response to submaximal and maximal exercise was evident (p < 0.05, d = 0.46). There were no gender differences for ARH (p > 0.05). The velocity at lactate threshold (vLT) correlated with the FORD response at rest, maximal exercise, and recovery (p < 0.05). Using the clinical POC redox test, an absence of oxidative stress after exhaustive exercise is evident in the nonfatigued elite endurance athlete. The blood antioxidant response (FORD) to exercise appears to be related to a key marker of aerobic fitness: vLT.

Peak Cardiorespiratory Responses of Patients with Subacute Stroke During Land and Aquatic Treadmill Exercise.

PubMed

Lee, Yong Ki; Kim, Bo Ryun; Han, Eun Young

2017-05-01

The aim of this work was to investigate the cardiorespiratory responses of patients with subacute stroke to exercise stress tests with aquatic and land treadmills. Twenty-one consecutive patients who presented with first-ever subacute stroke in 2013-2015. All subjects underwent symptom-limited incremental exercise testing with aquatic and land treadmills. Land treadmill speed started at 1.5 km/h and increased 0.5 km/h every 1 to 2 minutes until maximal tolerable speed was achieved. Thereafter, the grade was elevated by 2% every 2 minutes. In the aquatic treadmill test, subjects were submerged to the xiphoid in 28°C water. Treadmill speed started at 1.5 km/h and was increased 0.5 km/h every 2 minutes thereafter. Cardiorespiratory responses were recorded with aquatic and land treadmills. Compared to land treadmill exercise, aquatic treadmill exercise achieved significantly better peak VO2 (22.0 vs 20.0; P = 0.02), peak metabolic equivalents (6.3 vs 5.8; P = 0.02), and peak rating of perceived exertion (17.6 vs 18.4, P = 0.01). Heart rate and VO2 correlated significantly during both tests (land treadmill: r = 0.96, P < 0.001; aquatic treadmill: r = 0.99, P < 0.001). Aquatic treadmill exercise elicited significantly better peak cardiorespiratory responses than land treadmill exercise and may be as effective for early intensive aerobic training in subacute stroke patients.

Affective response to exercise as a component of exercise motivation: Attitudes, norms, self-efficacy, and temporal stability of intentions

PubMed Central

Kwan, Bethany M.; Bryan, Angela D.

2009-01-01

Problem: A positive affective response is associated with increased participation in voluntary exercise, but the mechanisms by which this occurs are not well known. Consistent with a Theory of Planned Behaviour perspective, we tested whether affective response to exercise leads to greater motivation in terms of attitudes, subjective norms, self-efficacy and intentions to exercise. We were also specifically interested in whether a positive affective response leads to more temporally stable intentions. Method: Participants (N = 127) self-reported Theory of Planned Behaviour constructs and exercise behavior at baseline and three months later, and provided reports of exercise-related affect during a 30-minute bout of moderate intensity treadmill exercise at baseline. Results: We show that participants who experience greater improvements in positive affect, negative affect and fatigue during exercise tended to report more positive attitudes, exercise self-efficacy and intentions to exercise three months later. Affective response was not predictive of subjective norms. As hypothesized, positive affective response was associated with more stable intentions over time. Conclusions: We conclude that a positive affective response to acute bouts of exercise can aid in building and sustaining exercise motivation over time. PMID:20161385

Impact of polyphenol antioxidants on cycling performance and cardiovascular function.

PubMed

Trinity, Joel D; Pahnke, Matthew D; Trombold, Justin R; Coyle, Edward F

2014-03-24

This investigation sought to determine if supplementation with polyphenol antioxidant (PA) improves exercise performance in the heat (31.5 °C, 55% RH) by altering the cardiovascular and thermoregulatory responses to exercise. Twelve endurance trained athletes ingested PA or placebo (PLAC) for 7 days. Consecutive days of exercise testing were performed at the end of the supplementation periods. Cardiovascular and thermoregulatory measures were made during exercise. Performance, as measured by a 10 min time trial (TT) following 50 min of moderate intensity cycling, was not different between treatments (PLAC: 292 ± 33 W and PA: 279 ± 38 W, p = 0.12). Gross efficiency, blood lactate, maximal neuromuscular power, and ratings of perceived exertion were also not different between treatments. Similarly, performance on the second day of testing, as assessed by time to fatigue at maximal oxygen consumption, was not different between treatments (PLAC; 377 ± 117 s vs. PA; 364 ± 128 s, p = 0.61). Cardiovascular and thermoregulatory responses to exercise were not different between treatments on either day of exercise testing. Polyphenol antioxidant supplementation had no impact on exercise performance and did not alter the cardiovascular or thermoregulatory responses to exercise in the heat.

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

NASA Technical Reports Server (NTRS)

Siconolfi, Steven F.; Charles, John B.

1992-01-01

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

Genetic testing for exercise prescription and injury prevention: AIS-Athlome consortium-FIMS joint statement.

PubMed

Vlahovich, Nicole; Hughes, David C; Griffiths, Lyn R; Wang, Guan; Pitsiladis, Yannis P; Pigozzi, Fabio; Bachl, Nobert; Eynon, Nir

2017-11-14

There has been considerable growth in basic knowledge and understanding of how genes are influencing response to exercise training and predisposition to injuries and chronic diseases. On the basis of this knowledge, clinical genetic tests may in the future allow the personalisation and optimisation of physical activity, thus providing an avenue for increased efficiency of exercise prescription for health and disease. This review provides an overview of the current status of genetic testing for the purposes of exercise prescription and injury prevention. As such there are a variety of potential uses for genetic testing, including identification of risks associated with participation in sport and understanding individual response to particular types of exercise. However, there are many challenges remaining before genetic testing has evidence-based practical applications; including adoption of international standards for genomics research, as well as resistance against the agendas driven by direct-to-consumer genetic testing companies. Here we propose a way forward to develop an evidence-based approach to support genetic testing for exercise prescription and injury prevention. Based on current knowledge, there is no current clinical application for genetic testing in the area of exercise prescription and injury prevention, however the necessary steps are outlined for the development of evidence-based clinical applications involving genetic testing.

Cardiorespiratory response to exercise testing in individuals with Alzheimer’s disease

PubMed Central

Billinger, Sandra A.; Vidoni, Eric D.; Honea, Robyn A.; Burns, Jeffrey M.

2011-01-01

Objective To exercise testing in AD and possible disease-related change over time. Though physical activity and fitness are receiving increased attention as a possible adjunct treatment for Alzheimer’s disease (AD), relatively little work has been done characterizing their physiologic response to exercise Design Retrospective assessment of a 2-year, observational study Setting University medical center Participants 50 nondemented individuals and 31 with AD Interventions None Main Outcome Measures Participants underwent a clinical dementia evaluation and performed an incremental exercise test using a treadmill and the modified Bruce protocol at baseline and at a two year follow-up. We examined oxygen consumption, minute ventilation, heart rate and ventilatory equivalents for oxygen and carbon dioxide at submaximal and peak exercise intensities to determine if the measures were different between groups or over time. Results AD and nondemented participants performed similarly at submaximal effort and both groups showed similar change in exercise response over 2 years. However, nondemented individuals had consistently higher values of oxygen consumption (p≤0.02) and minute ventilation at peak effort at baseline (p=0.003). Conclusions Individuals with AD demonstrate physiologic responses to submaximal exercise effort that are not significantly different than individuals without dementia. However, differences are apparent at the extreme of effort. PMID:22133248

Cardiorespiratory response to exercise testing in individuals with Alzheimer's disease.

PubMed

Billinger, Sandra A; Vidoni, Eric D; Honea, Robyn A; Burns, Jeffrey M

2011-12-01

To examine exercise testing response in Alzheimer's disease (AD) and possible disease-related change over time. Retrospective assessment of a 2-year observational study. University medical center. Individuals without dementia (n=50) and with AD (n=31). Not applicable. Participants underwent a clinical dementia evaluation and performed an incremental exercise test using a treadmill and the modified Bruce protocol at baseline and at a 2-year follow-up. We examined oxygen consumption, minute ventilation, heart rate, and ventilatory equivalents for oxygen and carbon dioxide at submaximal and peak exercise intensities to determine whether the measures were different between groups or over time. Participants with AD and those without dementia performed similarly at submaximal effort, and both groups showed similar changes in exercise response over 2 years. However, nondemented individuals had consistently higher values of oxygen consumption (P≤.02) and minute ventilation at peak effort at baseline (P=.003). Individuals with AD demonstrate physiologic responses to submaximal exercise effort that are not significantly different than individuals without dementia. However, differences are apparent at the extreme of effort. Copyright © 2011 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

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.

Pulmonary Artery Wedge Pressure Relative to Exercise Work Rate in Older Men and Women.

PubMed

Esfandiari, Sam; Wright, Stephen P; Goodman, Jack M; Sasson, Zion; Mak, Susanna

2017-07-01

An augmented pulmonary artery wedge pressure (PAWP) response may explain exercise intolerance in some humans. However, routine use of exercise hemodynamic testing is limited by a lack of data from normal older men and women. Our objective was to evaluate the exercise PAWP response and the potential for sexual dimorphism in healthy, nondyspneic older adults. Thirty-six healthy volunteers (18 men [54 ± 7 yr] and 18 women [58 ± 6 yr]) were studied at rest (control) and during two stages of semi-upright cycle ergometry, at heart rates of 100 bpm (light exercise) and 120 bpm (moderate exercise). Right heart catheterization was performed to measure pulmonary pressures. The PAWP response to exercise was assessed in context of exercise work rate and body size. At control, PAWP was similar between men and women. Work rates were significantly smaller in women at comparable HR (P < 0.001). PAWP increased similarly at light exercise, with no further increase at moderate exercise. When indexed to work rate alone or work rate adjusted to body weight and height, the PAWP response at light and moderate exercise was significantly elevated in women compared with men (P < 0.05 condition-sex interaction). The change in PAWP relative to the increase in cardiac output did not exceed 2 mm Hg·L·min in any volunteer at moderate exercise. The similar rise in the PAWP response to submaximal exercise occurs despite lower work rate in healthy older women compared with men, even when adjusted for smaller body size. It is important to consider sex in the development of normal reference ranges for exercise hemodynamic testing.

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.

Voluntary Exercise Produces Antidepressant and Anxiolytic Behavioral Effects in Mice

PubMed Central

Duman, Catharine H.; Schlesinger, Lee; Russell, David S.; Duman, Ronald S.

2008-01-01

Reports of beneficial effects of exercise on psychological health in humans are increasingly supported by basic research studies. Exercise is hypothesized to regulate antidepressant-related mechanisms and we therefore characterized the effects of chronic exercise in mouse behavioral paradigms relevant to antidepressant actions. Mice given free access to running wheels showed antidepressant-like behavior in learned helplessness, forced-swim (FST) and tail suspension paradigms. These responses were similar to responses of antidepressant drug-treated animals. When tested under conditions where locomotor activity was not altered, exercising mice also showed reduced anxiety compared to sedentary control mice. In situ hybridization analysis showed that BDNF mRNA was increased in specific subfields of hippocampus after wheel running. We chose one paradigm, the FST, in which to investigate a functional role for brain-derived neurotrophic factor (BDNF) in the behavioral response to exercise. We tested mice heterozygous for a deletion of the BDNF gene in the FST after wheel-running. Exercising wild-type mice showed the expected antidepressant-like behavioral response in the FST but exercise was ineffective in improving FST performance in heterozygous BDNF knockout mice. A possible functional contribution of a BDNF signaling pathway to FST performance in exercising mice was investigated using the specific MEK inhibitor PD184161 to block the MAPK signaling pathway. Subchronic administration of PD184161 to exercising mice blocked the antidepressant-like behavioral response seen in vehicle-treated exercising mice in the FST. In summary, chronic wheel-running exercise in mice results in antidepressant-like behavioral changes that may involve a BDNF related mechanism similar to that hypothesized for antidepressant drug treatment. PMID:18267317

[Clinical exercise testing and the Fick equation: strategic thinking for optimizing diagnosis].

PubMed

Perrault, H; Richard, R

2012-04-01

This article examines the expected exercise-induced changes in the components of the oxygen transport system as described by the Fick equation with a view to enable a critical analysis of a standard incremental exercise test to identify normal and abnormal patterns of responses and generate hypotheses as to potential physiological and/or pathophysiological causes. The text reviews basic physiological principals and provides useful reminders of standard equations that serve to integrate circulatory, respiratory and skeletal muscle functions. More specifically, the article provides a conceptual and quantitative framework linking the exercise-induced increase in whole body oxygen uptake to central circulatory and peripheral circulatory factors with the view to establish the normalcy of response. Thus, the article reviews the exercise response to cardiac output determinants and provides qualitative and quantitative perspective bases for making assumptions on the peripheral circulatory factors and oxygen use. Finally, the article demonstrates the usefulness of exercise testing as an effective integrative physiological approach to develop clinical reasoning or verify pathophysiological outcomes. Copyright © 2012 SPLF. Published by Elsevier Masson SAS. All rights reserved.

Ventilatory response to the onset of passive and active exercise in human subjects.

PubMed

Miyamura, M; Ishida, K; Yasuda, Y

1992-01-01

Ventilatory responses at the onset of passive and active exercise with different amount of exercising muscle mass were studied in 10 healthy male subjects. Four exercise tests were performed for each subject with appropriate intervals on the same day, i.e., two voluntary exercises of one leg or both legs and two passive exercises of one leg or both legs. Inspiratory minute volume (VI), end-tidal CO2 and O2 partial pressures (PETCO2, PETO2) were measured breath-by-breath using a hot-wire flowmeter, infrared CO2 analyzer, and a rapid O2 analyzer. Average values of VI were obtained from 5 breaths at rest preceding exercise and the first and second breaths after the onset of exercise. The ventilatory response to exercise was calculated as the difference (delta) between the mean of exercise VI and mean of resting VI. In this study, the PETCO2 decreased by about 0.5 Torr in four exercise tests, though the decrement of PETCO2 was not statistically significant. The average values and standard deviation of delta VI were 4.22 +/- 1.63 l/min for the one leg and 6.46 +/- 1.80 l/min for the two legs in the active exercise, and were 2.46 +/- 1.12 l/min for the one leg and 3.44 +/- 1.55 l/min for the two legs in the passive exercise, respectively. These results suggest that in awake conditions, the ventilatory response at the onset of passive or active exercise does not increase additively with the increasing amount of muscle mass being exercised.

33 CFR 154.1125 - Additional response plan requirements.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Sound: (A) Valdez; (B) Tatitlek; (C) Cordova; (D) Whittier; (E) Chenega; and (F) Fish hatcheries located...) Address the responsibilities required in § 154.1035(b)(3)(iii). (2) Exercises. Identification of exercise procedures that must— (i) Provide for two exercises of the oil spill removal organization each year that test...

30 CFR 254.42 - Exercises for your response personnel and equipment.

Code of Federal Regulations, 2012 CFR

2012-07-01

..., DEPARTMENT OF THE INTERIOR OFFSHORE OIL-SPILL RESPONSE REQUIREMENTS FOR FACILITIES LOCATED SEAWARD OF THE... facility or at a corporate location designated in the plan. Records showing that OSRO's and oil spill...) An annual spill management team tabletop exercise. The exercise must test the spill management team's...

30 CFR 254.42 - Exercises for your response personnel and equipment.

Code of Federal Regulations, 2014 CFR

2014-07-01

..., DEPARTMENT OF THE INTERIOR OFFSHORE OIL-SPILL RESPONSE REQUIREMENTS FOR FACILITIES LOCATED SEAWARD OF THE... facility or at a corporate location designated in the plan. Records showing that OSRO's and oil spill...) An annual spill management team tabletop exercise. The exercise must test the spill management team's...

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

PubMed

Tempest, Gavin D; Parfitt, Gaynor

2017-07-01

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

The importance of the function of exercise in the relationship between obligatory exercise and eating and body image concerns.

PubMed

De Young, Kyle P; Anderson, Drew A

2010-01-01

This study tested whether exercising in response to negative affect moderates the association between obligatory exercise and eating and body image psychopathology. Participants (n=226) completed the Eating Disorders Examination-Questionnaire (EDE-Q), Obligatory Exercise Questionnaire (OEQ), and a question assessing whether they ever exercise in response to negative affect. In total, 132 (58.4%) participants endorsed exercising in response to negative affect. Multiple regression analyses revealed significant main effects of negative affect motivated exercise, OEQ total scores, and gender on all four EDE-Q subscales and significant interactions of negative affect motivated exercise and OEQ scores on the Eating Concern, Shape Concern, and Weight Concern scales but not the Restraint scale of the EDE-Q. Obligatory exercisers may not demonstrate elevated eating and body image concerns in the absence of negative affect motivated exercise, providing further support of the importance of the function of exercise.

[Associations of the work duration, sleep duration and number of holidays with an exaggerated blood pressure response during an exercise stress test among workers].

PubMed

Michishita, Ryoma; Ohta, Masanori; Ikeda, Masaharu; Jiang, Ying; Yamato, Hiroshi

2016-01-01

It has been reported that an exaggerated systolic blood pressure (ESBP) response during exercise, even if resting blood pressure is normal, is associated with an increased risk of future hypertension and cardiovascular disease (CVD). This study was designed to investigate the relationships of work duration, sleep duration and number of holidays with blood pressure response during an exercise stress test among normotensive workers. The subjects were 362 normotensive workers (79 males and 283 females; age, 49.1 years). A multi-stage graded submaximal exercise stress test was performed on each subject using an electric bicycle ergometer. The workload was increased every 3 minutes, and blood pressure was measured at rest and during the last 1 minute of each stage. In this study, an ESBP response during exercise was defined according to the criteria of the Framingham Study (peak systolic blood pressure ≥210 mmHg in males, or ≥190 mmHg in females). Working environments, work duration, sleep duration, number of holidays, and physical activity during commuting and work, and leisure time exercise duration were evaluated using a questionnaire. An ESBP response during exercise was observed in 94 (26.0%) workers. The adjusted odds ratio for the prevalence of an ESBP response during exercise was found to be significantly higher with an increase in work duration, decreases in sleep duration and number of holidays (p<0.05, respectively). Moreover, the highest work duration with lowest sleep duration and number of holidays groups had significantly higher adjusted odds ratio for the prevalence of an ESBP response during exercise than the lowest work duration with highest sleep duration and number of holidays groups (p<0.05, respectively). Based on our results, we consider that the assessment of blood pressure response during exercise and daily life are necessary to prevent the incidence of future hypertension, CVD and death due to overwork in workers with long-work duration, short sleep duration and small number of holidays.

Baroreflex-mediated heart rate and vascular resistance responses 24 h after maximal exercise

NASA Technical Reports Server (NTRS)

Convertino, Victor A.

2003-01-01

INTRODUCTION: Plasma volume, heart rate (HR) variability, and stimulus-response relationships for baroreflex control of forearm vascular resistance (FVR) and HR were studied in eight healthy men after and without performing a bout of maximal exercise to test the hypotheses that acute expansion of plasma volume is associated with 1) reduction in baroreflex-mediated HR response, and 2) altered operational range for central venous pressure (CVP). METHODS: The relationship between stimulus (DeltaCVP) and vasoconstrictive reflex response (DeltaFVR) during unloading of cardiopulmonary baroreceptors was assessed with lower-body negative pressure (LBNP, 0, -5, -10, -15, -20 mm Hg). The relationship between stimulus (Deltamean arterial pressure (MAP)) and cardiac reflex response (DeltaHR) during loading of arterial baroreceptors was assessed with steady-state infusion of phenylephrine (PE) designed to increase MAP by 15 mm Hg alone and during application of LBNP (PE+LBNP) and neck pressure (PE+LBNP+NP). Measurements of vascular volume and autonomic baroreflex responses were conducted on two different test days, each separated by at least 1 wk. On one day, baroreflex response was tested 24 h after graded cycle exercise to volitional exhaustion. On another day, measurement of baroreflex response was repeated with no exercise (control). The order of exercise and control treatments was counterbalanced. RESULTS: Baseline CVP was elevated (P = 0.04) from a control value of 10.5 +/- 0.4 to 12.3 +/- 0.4 mm Hg 24 h after exercise. Average DeltaFVR/DeltaCVP during LBNP was not different (P = 0.942) between the exercise (-1.35 +/- 0.32 pru x mm Hg-1) and control (-1.32 +/- 0.36 pru x mm Hg-1) conditions. However, maximal exercise caused a shift along the reflex response relationship to a higher CVP and lower FVR. HR baroreflex response (DeltaHR/DeltaMAP) to PE+LBNP+NP was lower (P = 0.015) after maximal exercise (-0.43 +/- 0.15 beats x min-1 x mm Hg-1) compared with the control condition (-0.83 +/- 0.14 beats x min-1 x mm Hg-1). CONCLUSION: Expansion of vascular volume after acute exercise is associated with altered operational range for CVP and reduced HR response to arterial baroreceptor stimulation.

The influence of α-adducin gene polymorphism on response of blood pressure to exercise in patients with hypertension.

PubMed

Alioğlu, Emin; Ercan, Ertuğrul; Tengiz, Istemihan; Türk, Uğur Onsel; Ergün, Metin; Akgöz, Semra; Işlegen, Cetin; Berdeli, Afig

2010-10-01

Clinical studies have indicated that an excessive response of blood pressure (BP) to exercise predicts risk of cardiovascular mortality. Although the mechanism responsible for the excessive BP response to exercise has not been revealed, there are some plausible mechanisms linking with underlying structural abnormalities in the cardiovascular system. Carriers of the Trp460 allele of the α-adducin Gly460Trp polymorphism have an increased risk of hypertension. The aim of the present study was to examine the influence of α-adducin gene polymorphism on response of BP to exercise in patients with hypertension. The cross-sectional observational study consisted of 49 hypertensive patients (29 women and 20 men; mean age, 53.1±8.8 years). All participants underwent a multistage exercise treadmill test according to the Bruce protocol. Arterial BPs were compared at rest, peak exercise and end of the recovery phase. Patients were classified according to their α-adducin gene polymorphisms; Gly460Gly homozygotes - Group 1 (n=28) and Trp460Trp homozygotes and Gly460Trp heterozygotes - Group 2 (n=21). Statistical analysis was performed using Chi-square, unpaired t, Mann-Whitney U and ANCOVA tests. Mean exercise duration and mean exercise capacity in metabolic equivalents were not different between Group 1 and 2. The major finding of the study was that systolic BP responses at peak exercise and recovery period (3. min) were significantly higher (p=0.036) in hypertensive patients carrying at least one Trp460 allele of the α-adducin gene. Our results suggest that genetic variants that alter renal function and/or vasoreactivity are logical candidates to explain some of the individual variability in the BP response to exercise.

The Effects of Different Training Backgrounds on VO2 Responses to All-Out and Supramaximal Constant-Velocity Running Bouts

PubMed Central

de Aguiar, Rafael Alves; Lisbôa, Felipe Domingos; Turnes, Tiago; Cruz, Rogério Santos de Oliveira; Caputo, Fabrizio

2015-01-01

To investigate the impact of different training backgrounds on pulmonary oxygen uptake (V̇O2) responses during all-out and supramaximal constant-velocity running exercises, nine sprinters (SPRs) and eight endurance runners (ENDs) performed an incremental test for maximal aerobic velocity (MAV) assessment and two supramaximal running exercises (1-min all-out test and constant-velocity exercise). The V̇O2 responses were continuously determined during the tests (K4b2, Cosmed, Italy). A mono-exponential function was used to describe the V̇O2 onset kinetics during constant-velocity test at 110%MAV, while during 1-min all-out test the peak of V̇O2 (V̇O2peak), the time to achieve the V̇O2peak (tV̇O2peak) and the V̇O2 decrease at last of the test was determined to characterize the V̇O2 response. During constant-velocity exercise, ENDs had a faster V̇O2 kinetics than SPRs (12.7 ± 3.0 vs. 19.3 ± 5.6 s; p < 0.001). During the 1-min all-out test, ENDs presented slower tV̇O2peak than SPRs (40.6 ± 6.8 and 28.8 ± 6.4 s, respectively; p = 0.002) and had a similar V̇O2peak relative to the V̇O2max (88 ± 8 and 83 ± 6%, respectively; p = 0.157). Finally, SPRs was the only group that presented a V̇O2 decrease in the last half of the test (-1.8 ± 2.3 and 3.5 ± 2.3 ml.kg-1.min-1, respectively; p < 0.001). In summary, SPRs have a faster V̇O2 response when maximum intensity is required and a high maximum intensity during all-out running exercise seems to lead to a higher decrease in V̇O2 in the last part of the exercise. PMID:26252001

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.

Impaired chronotropic response to physical activities in heart failure patients.

PubMed

Shen, Hong; Zhao, Jianrong; Zhou, Xiaohong; Li, Jingbo; Wan, Qing; Huang, Jing; Li, Hui; Wu, Liqun; Yang, Shungang; Wang, Ping

2017-05-25

While exercise-based cardiac rehabilitation has a beneficial effect on heart failure hospitalization and mortality, it is limited by the presence of chronotropic incompetence (CI) in some patients. This study explored the feasibility of using wearable devices to assess impaired chronotropic response in heart failure patients. Forty patients with heart failure (left ventricular ejection fraction, LVEF: 44.6 ± 5.8; age: 54.4 ± 11.7) received ECG Holter and accelerometer to monitor heart rate (HR) and physical activities during symptom-limited treadmill exercise testing, 6-min hall walk (6MHW), and 24-h daily living. CI was defined as maximal HR during peak exercise testing failing to reach 70% of age-predicted maximal HR (APMHR, 220 - age). The correlation between HR and physical activities in Holter-accelerometer recording was analyzed. Of 40 enrolled patients, 26 were able to perform treadmill exercise testing. Based on exercise test reports, 13 (50%) of 26 patients did not achieve at least 70% of APMHR (CI patients). CI patients achieved a lower % APMHR (62.0 ± 6.3%) than non-CI patients who achieved 72.0 ± 1.2% of APMHR (P < 0.0001). When Holter-accelerometer recording was used to assess chronotropic response, the percent APMHR achieved during 6MHW and physical activities was significantly lower in CI patients than in non-CI patients. CI patients had a significantly shorter 6MHW distance and less physical activity intensity than non-CI patients. The study found impaired chronotropic response in 50% of heart failure patients who took treadmill exercise testing. The wearable Holter-accelerometer recording could help to identify impaired chronotropic response to physical activities in heart failure patients. ClinicalTrials.gov ID NCT02358603 . Registered 16 May 2014.

Naloxone decreases the inhibitory effect of alprazolam on the release of adrenocorticotropin/cortisol induced by physical exercise in man

PubMed Central

Coiro, Vittorio; Volpi, Riccardo; Casti, Amos; Maffei, Maria Ludovica; Stella, Adriano; Volta, Elio; Chiodera, Paolo

2011-01-01

AIMS To establish the possible involvement of alprazolam (ALP) and/or opiates in the mechanism underlying the ACTH/cortisol response to physical exercise. METHODS Tests were carried out under basal conditions (exercise control test), exercise plus ALP (50 µg at time −90 min), naloxone (10 mg at time 0) or ALP plus naloxone. Plasma ACTH and serum cortisol concentrations were evaluated in blood samples taken before, during and after the bicycle ergometer tests. RESULTS ACTH and cortisol concentrations rose significantly after physical exercise. Maximum peak at time 15 min (P≤ 0.01 vs. baseline) for ACTH and at time 30 min (P≤ 0.01 vs. baseline) for cortisol. In the presence of naloxone, the ACTH and cortisol responses were significantly increased (maximum peak at time 20 min, P≤ 0.02 vs. control test for ACTH, and at time 30 min (P≤ 0.01 vs. baseline) for cortisol) whereas they were abolished by ALP. When ALP and naloxone were given together, the inhibitory effect of ALP was partial. CONCLUSIONS These data demonstrate an inhibitory effect of ALP in the regulation of the ACTH/cortisol response to physical exercise in man and suggest that GABAergic receptor activating benzodiazepines and opioids interact in the neuroendocrine secretion of ACTH/cortisol. PMID:21564163

Resistance exercise training and the orthostatic response

NASA Technical Reports Server (NTRS)

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

1997-01-01

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

Physiological responses during exercise with video games in patients with cystic fibrosis: A systematic review.

PubMed

Carbonera, Raquel Pinto; Vendrusculo, Fernanda Maria; Donadio, Márcio Vinícius Fagundes

2016-10-01

Interactive video games are recently being used as an exercise tool in cystic fibrosis (CF). This study aimed to assess the literature describing whether video games generate a physiological response similar to the exercise intensity needed for training in CF. An online search in PubMed, Embase, Cochrane, SciELO, LILACS and PEDro databases was conducted and original studies describing physiological responses of the use of video games as exercise in CF were included. In four, out of five studies, the heart rate achieved during video games was within the standards recommended for training (60-80%). Two studies assessed VO 2 and showed higher levels compared to the six-minute walk test. No desaturation was reported. Most games were classified as moderate intensity. Only one study used a maximum exercise test as comparator. Interactive video games generate a heart rate response similar to the intensity required for training in CF patients. Copyright © 2016 Elsevier Ltd. All rights reserved.

The protective effects of free wheel-running against cocaine psychomotor sensitization persist after exercise cessation in C57BL/6J mice.

PubMed

Lespine, L-F; Tirelli, E

2015-12-03

Previous literature suggests that free access to a running wheel can attenuate the behavioral responsiveness to addictive drugs in rodents. In a few studies, wheel-running cessation accentuated drug responsiveness. Here, we tested whether free wheel-running cessation is followed by (1) an accentuation or (2) an attenuation of cocaine psychomotor sensitization, knowing that no cessation of (continuous) wheel-running is associated with an attenuation of cocaine responsiveness. Male C57BL/6J mice, aged 35 days, were housed singly either with (exercising mice) or without (non-exercising mice) a running wheel. At the end of a period of 36 days, half of the exercising mice were deprived of their wheel whereas the other half of exercising mice kept their wheel until the end of experimentation (which lasted 85 days). The non-exercising mice were housed without wheel throughout experimentation. Testing took place 3 days after exercise cessation. After 2 once-daily drug-free test sessions, mice were tested for initiation of psychomotor sensitization over 13 once-daily injections of 8 mg/kg cocaine. Post-sensitization conditioned activation (saline challenge) and long-term expression of sensitization were assessed 2 or 30 days after the last sensitizing injection (same treatments as for initiation of sensitization), respectively. Exercising mice and mice undergoing wheel-running cessation exhibited comparable degrees of attenuation of all cocaine effects in comparison with the continuously non-exercising mice, which showed the greatest effects. Thus, the efficaciousness of wheel-running at attenuating cocaine sensitization not only resisted to exercise cessation but was also unambiguously persistent (an important effect rarely reported in previous literature). Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

Oxygen Uptake Responses to Submaximal Exercise Loads Do Not Change During Long-Duration Space Flight

NASA Technical Reports Server (NTRS)

Moore, Alan D., Jr.; Evetts, Simon N.; Feiveson, Alan H.; Lee, S. M. C.; McCleary, Frank A.; Platts, Steven H.; Ploutz-Snyder, Lori

2011-01-01

In previous publications we have reported that the heart rate (HR) responses to graded submaximal exercise tests are elevated during long-duration International Space Station (ISS) flights. Furthermore, the elevation in HR appears greater earlier, rather than later, during the missions. A potential confounder in the interpretation of HR results from graded exercise tests on ISS is that the cycle ergometer used (CEVIS) is vibration-isolated from the station structure. This feature causes the CEVIS assembly to sway slightly during its use and debriefing comments by some crewmembers indicate that there is a "learning curve" associated with CEVIS use. Therefore, one could not exclude the possibility that the elevated HRs experienced in the early stages of ISS missions were related to a lowered metabolic efficiency of CEVIS exercise that would raise the submaximal oxygen uptake (VO2) associated with graded exercise testing work rates.

Active Female Maximal and Anaerobic Threshold Cardiorespiratory Responses to Six Different Water Aerobics Exercises

ERIC Educational Resources Information Center

Antunes, Amanda H.; Alberton, Cristine L.; Finatto, Paula; Pinto, Stephanie S.; Cadore, Eduardo L.; Zaffari, Paula; Kruel, Luiz F. M.

2015-01-01

Purpose: Maximal tests conducted on land are not suitable for the prescription of aquatic exercises, which makes it difficult to optimize the intensity of water aerobics classes. The aim of the present study was to evaluate the maximal and anaerobic threshold cardiorespiratory responses to 6 water aerobics exercises. Volunteers performed 3 of the…

Increasing blood flow to exercising muscle attenuates systemic cardiovascular responses during dynamic exercise in humans

PubMed Central

Ichinose-Kuwahara, Tomoko; Kondo, Narihiko; Nishiyasu, Takeshi

2015-01-01

Reducing blood flow to working muscles during dynamic exercise causes metabolites to accumulate within the active muscles and evokes systemic pressor responses. Whether a similar cardiovascular response is elicited with normal blood flow to exercising muscles during dynamic exercise remains unknown, however. To address that issue, we tested whether cardiovascular responses are affected by increases in blood flow to active muscles. Thirteen healthy subjects performed dynamic plantarflexion exercise for 12 min at 20%, 40%, and 60% of peak workload (EX20, EX40, and EX60) with their lower thigh enclosed in a negative pressure box. Under control conditions, the box pressure was the same as the ambient air pressure. Under negative pressure conditions, beginning 3 min after the start of the exercise, the box pressure was decreased by 20, 45, and then 70 mmHg in stepwise fashion with 3-min step durations. During EX20, the negative pressure had no effect on blood flow or the cardiovascular responses measured. However, application of negative pressure increased blood flow to the exercising leg during EX40 and EX60. This increase in blood flow had no significant effect on systemic cardiovascular responses during EX40, but it markedly attenuated the pressor responses otherwise seen during EX60. These results demonstrate that during mild exercise, normal blood flow to exercising muscle is not a factor eliciting cardiovascular responses, whereas it elicits an important pressor effect during moderate exercise. This suggests blood flow to exercising muscle is a major determinant of cardiovascular responses during dynamic exercise at higher than moderate intensity. PMID:26377556

Genetic Influences on Physiological and Subjective Responses to an Aerobic Exercise Session among Sedentary Adults

PubMed Central

Karoly, Hollis C.; Stevens, Courtney J.; Magnan, Renee E.; Harlaar, Nicole; Hutchison, Kent E.; Bryan, Angela D.

2012-01-01

Objective. To determine whether genetic variants suggested by the literature to be associated with physiology and fitness phenotypes predicted differential physiological and subjective responses to a bout of aerobic exercise among inactive but otherwise healthy adults. Method. Participants completed a 30-minute submaximal aerobic exercise session. Measures of physiological and subjective responding were taken before, during, and after exercise. 14 single nucleotide polymorphisms (SNPs) that have been previously associated with various exercise phenotypes were tested for associations with physiological and subjective response to exercise phenotypes. Results. We found that two SNPs in the FTO gene (rs8044769 and rs3751812) were related to positive affect change during exercise. Two SNPs in the CREB1 gene (rs2253206 and 2360969) were related to change in temperature during exercise and with maximal oxygen capacity (VO2 max). The SLIT2 SNP rs1379659 and the FAM5C SNP rs1935881 were associated with norepinephrine change during exercise. Finally, the OPRM1 SNP rs1799971 was related to changes in norepinephrine, lactate, and rate of perceived exertion (RPE) during exercise. Conclusion. Genetic factors influence both physiological and subjective responses to exercise. A better understanding of genetic factors underlying physiological and subjective responses to aerobic exercise has implications for development and potential tailoring of exercise interventions. PMID:22899923

High intensity intermittent games-based activity and adolescents' cognition: moderating effect of physical fitness.

PubMed

Cooper, Simon B; Dring, Karah J; Morris, John G; Sunderland, Caroline; Bandelow, Stephan; Nevill, Mary E

2018-05-08

An acute bout of exercise elicits a beneficial effect on subsequent cognitive function in adolescents. The effect of games-based activity, an ecologically valid and attractive exercise model for young people, remains unknown; as does the moderating effect of fitness on the acute exercise-cognition relationship. Therefore, the aim of the present study was to examine the effect of games-based activity on subsequent cognition in adolescents, and the moderating effect of fitness on this relationship. Following ethical approval, 39 adolescents (12.3 ± 0.7 year) completed an exercise and resting trial in a counterbalanced, randomised crossover design. During familiarisation, participants completed a multi-stage fitness test to predict VO 2 peak. The exercise trial consisted of 60-min games-based activity (basketball), during which heart rate was 158 ± 11 beats∙min - 1 . A battery of cognitive function tests (Stroop test, Sternberg paradigm, trail making and d2 tests) were completed 30-min before, immediately following and 45-min following the basketball. Response times on the complex level of the Stroop test were enhanced both immediately (p = 0.021) and 45-min (p = 0.035) post-exercise, and response times on the five item level of the Sternberg paradigm were enhanced immediately post-exercise (p = 0.023). There were no effects on the time taken to complete the trail making test or any outcome of the d2 test. In particular, response times were enhanced in the fitter adolescents 45-min post-exercise on both levels of the Stroop test (simple, p = 0.005; complex, p = 0.040) and on the three item level of the Sternberg paradigm immediately (p = 0.017) and 45-min (p = 0.008) post-exercise. Games-based activity enhanced executive function and working memory scanning speed in adolescents, an effect particularly evident in fitter adolescents, whilst the high intensity intermittent nature of games-based activity may be too demanding for less fit children.

Cardio-respiratory and plasma lactate responses to exercise with low draught resistances in standardbred trotters.

PubMed

Gottlieb-Vedi, M; Essén-Gustavsson, B; Lindholm, A

1996-12-01

Five Standardbred trotters performed treadmill exercise with incrementally increasing trotting velocities for 2 min intervals in three different tests until fatigue. Each test was performed with draught loads of either 10, 20 or 30 kilopond (kp). Each trotting interval was followed by 2 min periods at a walk without draught load. Recordings were made of heart rate (HR), respiratory rate (RR), plasma lactate (PLA) and stride frequency (SF) at the end of each trotting interval. The HR increased to average values of 191 +/- 10,203 +/- 10 and 214 +/- 7 bpm and PLA increased to 3.8 +/- 0.7, 7.3 +/- 3.8 and 10.8 +/- 6.4 mmol/l at 9 m/s in the three tests, respectively. The HR response to exercise was significantly higher with increasing draught loads, and PLA was significantly higher with 30 kp compared to 10 kp draught resistance. The lowest respiratory rate was seen in the test with 30 kp loading. Peak oxygen uptake (VO2peak) was measured in a separate test on a sloped treadmill with increasing velocities without draught load and averaged 70.4 +/- 9.11/min. Muscle biopsies were taken from the gluteus muscle. Individual variations were seen in VO2peak, muscle fibre composition and HR and PLA responses to exercise. In conclusion, at a certain velocity a small increase in draught resistance from 10 to 30 kp significantly increases both the HR and PLA responses. At comparable work intensities the horses differed in circulatory and metabolic responses to exercise.

Exercise responses in patients with chronically high creatine kinase levels.

PubMed

Cooper, Christopher B; Dolezal, Brett A; Neufeld, Eric V; Shieh, Perry; Jenner, John R; Riley, Marshall

2017-08-01

Elevated serum creatine kinase (CK) is often taken to reflect muscle disease, but many individuals have elevated CK without a specific diagnosis. How elevated CK reflects muscle metabolism during exercise is not known. Participants (46 men, 48 women) underwent incremental exercise testing to assess aerobic performance, cardiovascular response, and ventilatory response. Serum lactate, ammonia, and CK were measured at rest, 4 minutes into exercise, and 2 minutes into recovery. High-CK and control subjects demonstrated similar aerobic capacities and cardiovascular responses to incremental exercise. Those with CK ≥ 300 U/L exhibited significantly higher lactate and ammonia levels after maximal exercise, together with increased ventilatory responses, whereas those with CK ≥200 U/L but ≤ 300 U/L did not. We recommend measurement of lactate and ammonia profiles during a maximal incremental exercise protocol to help identify patients who warrant muscle biopsy to rule out myopathy. Muscle Nerve 56: 264-270, 2017. © 2016 Wiley Periodicals, Inc.

The Effects of Acute Exercise on Memory and Brain-Derived Neurotrophic Factor (BDNF).

PubMed

Etnier, Jennifer L; Wideman, Laurie; Labban, Jeffrey D; Piepmeier, Aaron T; Pendleton, Daniel M; Dvorak, Kelly K; Becofsky, Katie

2016-08-01

Acute exercise benefits cognition, and some evidence suggests that brain-derived neurotrophic factor (BDNF) plays a role in this effect. The purpose of this study was to explore the dose-response relationship between exercise intensity, memory, and BDNF. Young adults completed 3 exercise sessions at different intensities relative to ventilator threshold (Vt) (VO 2max , Vt - 20%, Vt + 20%). For each session, participants exercised for approximately 30 min. Following exercise, they performed the Rey Auditory Verbal Learning Test (RAVLT) to assess short-term memory, learning, and long-term memory recall. Twenty-four hours later, they completed the RAVLT recognition trial, which provided another measure of long-term memory. Blood was drawn before exercise, immediately postexercise, and after the 30-min recall test. Results indicated that long-term memory as assessed after the 24-hr delay differed as a function of exercise intensity with the largest benefits observed following maximal intensity exercise. BDNF data showed a significant increase in response to exercise; however, there were no differences relative to exercise intensity and there were no significant associations between BDNF and memory. Future research is warranted so that we can better understand how to use exercise to benefit cognitive performance.

Health-related variables and predictors of Health-promoting Lifestyle in cardiovascular disease patients.

PubMed

Mohsenipouya, Hossein; Majlessi, Fereshteh; Shojaeizadeh, Davood; Foroushani, Abbas Rahimi; Ghafari, Rahman; Habibi, Vali; Makrani, Azam Seyfi

2016-04-01

The principal cause for death in the world is cardiovascular disease. Poor lifestyle is a contributing element in this regard. The objective of this study was to estimate the effects of health-related variables and lifestyle variables on the results of exercise stress tests in patients with cardiovascular disease in Iran. The study population in this case-control study was 220 patients who were candidates for exercise stress tests in Mazandaran Province (Iran) in 2015. The patients were divided randomly into two groups based on the results of their exercise stress tests, i.e., positive (110 patients) and negative (110 patients). The data collection tool was a standard questionnaire entitled "Health promotion lifestyle profile-II." The data were analyzed using mean, standard deviation, the chi-squared test, and logistic regression by SPSS version 22 software. The risk of a positive exercise stress test increases with age. The age group above 65 was 1.049 times more at risk of a positive exercise stress test than the age group of less than 45. The people with dyslipidemia had 1.635 times greater risk of positive exercise stress tests than the group without dyslipidemia. In addition, patients with hypertension had 1.579 times greater risk of positive exercise stress tests than the group without hypertension. The lack of individual health responsibility (Odds ratio (OR): 1.622), stress management (OR: 1.592), and physical activity (OR: 1.245) contributed more to positive exercise tests than the other risk factors. Educational interventions can improve the responsibility for health, physical activity, and stress management among people with the risk of cardiovascular disease.

Clinical Usefulness of Response Profiles to Rapidly Incremental Cardiopulmonary Exercise Testing

PubMed Central

Ramos, Roberta P.; Alencar, Maria Clara N.; Treptow, Erika; Arbex, Flávio; Ferreira, Eloara M. V.; Neder, J. Alberto

2013-01-01

The advent of microprocessed “metabolic carts” and rapidly incremental protocols greatly expanded the clinical applications of cardiopulmonary exercise testing (CPET). The response normalcy to CPET is more commonly appreciated at discrete time points, for example, at the estimated lactate threshold and at peak exercise. Analysis of the response profiles of cardiopulmonary responses at submaximal exercise and recovery, however, might show abnormal physiologic functioning which would not be otherwise unraveled. Although this approach has long been advocated as a key element of the investigational strategy, it remains largely neglected in practice. The purpose of this paper, therefore, is to highlight the usefulness of selected submaximal metabolic, ventilatory, and cardiovascular variables in different clinical scenarios and patient populations. Special care is taken to physiologically justify their use to answer pertinent clinical questions and to the technical aspects that should be observed to improve responses' reproducibility and reliability. The most recent evidence in favor of (and against) these variables for diagnosis, impairment evaluation, and prognosis in systemic diseases is also critically discussed. PMID:23766901

Translation of incremental talk test responses to steady-state exercise training intensity.

PubMed

Lyon, Ellen; Menke, Miranda; Foster, Carl; Porcari, John P; Gibson, Mark; Bubbers, Terresa

2014-01-01

The Talk Test (TT) is a submaximal, incremental exercise test that has been shown to be useful in prescribing exercise training intensity. It is based on a subject's ability to speak comfortably during exercise. This study defined the amount of reduction in absolute workload intensity from an incremental exercise test using the TT to give appropriate absolute training intensity for cardiac rehabilitation patients. Patients in an outpatient rehabilitation program (N = 30) performed an incremental exercise test with the TT given every 2-minute stage. Patients rated their speech comfort after reciting a standardized paragraph. Anything other than a "yes" response was considered the "equivocal" stage, while all preceding stages were "positive" stages. The last stage with the unequivocally positive ability to speak was the Last Positive (LP), and the preceding stages were (LP-1 and LP-2). Subsequently, three 20-minute steady-state training bouts were performed in random order at the absolute workload at the LP, LP-1, and LP-2 stages of the incremental test. Speech comfort, heart rate (HR), and rating of perceived exertion (RPE) were recorded every 5 minutes. The 20-minute exercise training bout was completed fully by LP (n = 19), LP-1 (n = 28), and LP-2 (n = 30). Heart rate, RPE, and speech comfort were similar through the LP-1 and LP-2 tests, but the LP stage was markedly more difficult. Steady-state exercise training intensity was easily and appropriately prescribed at intensity associated with the LP-1 and LP-2 stages of the TT. The LP stage may be too difficult for patients in a cardiac rehabilitation program.

Acute coordinative exercise improves attentional performance in adolescents.

PubMed

Budde, Henning; Voelcker-Rehage, Claudia; Pietrabyk-Kendziorra, Sascha; Ribeiro, Pedro; Tidow, Günter

2008-08-22

Teachers complain about growing concentration deficits and reduced attention in adolescents. Exercise has been shown to positively affect cognitive performance. Due to the neuronal connection between the cerebellum and the frontal cortex, we hypothesized that cognitive performance might be influenced by bilateral coordinative exercise (CE) and that its effect on cognition might be already visible after short bouts of exercise. One hundred and fifteen healthy adolescents aged 13-16 years of an elite performance school were randomly assigned to an experimental and a control group and tested using the d2-test, a test of attention and concentration. Both groups performed the d2-test after a regular school lesson (pre-test), after 10 min of coordinative exercise and of a normal sport lesson (NSL, control group), respectively (post-test). Exercise was controlled for heart rate (HR). CE and NSL enhanced the d2-test performance from pre- to post-test significantly. ANOVA revealed a significant group (CE, NSL) by performance interaction in the d2-test indicating a higher improvement of CE as compared to NSL. HR was not significantly different between the groups. CE was more effective in completing the concentration and attention task. With the HR being the same in both groups we assume that the coordinative character of the exercise might be responsible for the significant differences. CE might lead to a pre-activation of parts of the brain which are also responsible for mediating functions like attention. Thus, our results support the request for more acute CE in schools, even in elite performance schools.

Increasing blood flow to exercising muscle attenuates systemic cardiovascular responses during dynamic exercise in humans.

PubMed

Ichinose, Masashi; Ichinose-Kuwahara, Tomoko; Kondo, Narihiko; Nishiyasu, Takeshi

2015-11-15

Reducing blood flow to working muscles during dynamic exercise causes metabolites to accumulate within the active muscles and evokes systemic pressor responses. Whether a similar cardiovascular response is elicited with normal blood flow to exercising muscles during dynamic exercise remains unknown, however. To address that issue, we tested whether cardiovascular responses are affected by increases in blood flow to active muscles. Thirteen healthy subjects performed dynamic plantarflexion exercise for 12 min at 20%, 40%, and 60% of peak workload (EX20, EX40, and EX60) with their lower thigh enclosed in a negative pressure box. Under control conditions, the box pressure was the same as the ambient air pressure. Under negative pressure conditions, beginning 3 min after the start of the exercise, the box pressure was decreased by 20, 45, and then 70 mmHg in stepwise fashion with 3-min step durations. During EX20, the negative pressure had no effect on blood flow or the cardiovascular responses measured. However, application of negative pressure increased blood flow to the exercising leg during EX40 and EX60. This increase in blood flow had no significant effect on systemic cardiovascular responses during EX40, but it markedly attenuated the pressor responses otherwise seen during EX60. These results demonstrate that during mild exercise, normal blood flow to exercising muscle is not a factor eliciting cardiovascular responses, whereas it elicits an important pressor effect during moderate exercise. This suggests blood flow to exercising muscle is a major determinant of cardiovascular responses during dynamic exercise at higher than moderate intensity. Copyright © 2015 the American Physiological Society.

A comparison of 2 circuit exercise training techniques for eliciting matched metabolic responses in persons with paraplegia.

PubMed

Nash, Mark S; Jacobs, Patrick L; Woods, Jeffrey M; Clark, James E; Pray, Tanya A; Pumarejo, Alex E

2002-02-01

To test whether acute metabolic (VO(2)), chronotropic (heart rate), and perceptual (rating of perceived exertion; RPE) responses to exercise by persons with paraplegia differ when the exercise is on a multistation isoinertial exercise system (MultiGym) or on a customized system of Thera-Band resistance bands (ElasticGym). Within-subjects comparison of 2 treatments. Academic medical center. Sixteen men and 1 woman with complete paraplegia (T4-L1), as defined by the American Spinal Injury Association. A circuit resistance training (CRT) program for persons with paraplegia was adapted to both a MultiGym and a customized ElasticGym. Exercises used for training and testing used 6 resistance maneuvers at 50% of the 1-repetition maximum (1-RM), with interposed rapid arm spinning. Subjects were habituated to both conditions for 2 weeks before testing on randomized nonconsecutive days. VO(2) (L/min) was measured by portable spirometry, heart rate (beats/min) by a chest strap monitor, and RPE by the Borg Scale of Perceived Exertion (6-20). No significant effects of test condition on average VO(2) or heart rate were observed, with differences between conditions reflecting only .08L/min and 6.4 beats/min, respectively. Average RPE was significantly higher in testing under the ElasticGym condition (P < .05). CRT on a customized ElasticGym system elicited acute metabolic and chronotropic responses that did not differ from responses to exercise on a MultiGym, though RPE was greater with the ElasticGym. Copyright 2002 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation

Utility of the exercise electrocardiogram testing in sudden cardiac death risk stratification.

PubMed

Refaat, Marwan M; Hotait, Mostafa; Tseng, Zian H

2014-07-01

Sudden cardiac death (SCD) remains a major public health problem. Current established criteria identifying those at risk of sudden arrhythmic death, and likely to benefit from implantable cardioverter defibrillators (ICDs), are neither sensitive nor specific. Exercise electrocardiogram (ECG) testing was traditionally used for information concerning patients' symptoms, exercise capacity, cardiovascular function, myocardial ischemia detection, and hemodynamic responses during activity in patients with hypertrophic cardiomyopathy. We conducted a systematic review of MEDLINE on the utility of exercise ECG testing in SCD risk stratification. Exercise testing can unmask suspected primary electrical diseases in certain patients (catecholaminergic polymorphic ventricular tachycardia or concealed long QT syndrome) and can be effectively utilized to risk stratify patients at an increased (such as early repolarization syndrome and Brugada syndrome) or decreased risk of SCD, such as the loss of preexcitation on exercise testing in asymptomatic Wolff-Parkinson-White syndrome. Exercise ECG testing helps in SCD risk stratification in patients with and without arrhythmogenic hereditary syndromes. © 2014 Wiley Periodicals, Inc.

Creatine kinase response to high-intensity aerobic exercise in adult-onset muscular dystrophy.

PubMed

Andersen, Søren P; Sveen, Marie-Louise; Hansen, Regitze S; Madsen, Karen L; Hansen, Jonas B; Madsen, Mads; Vissing, John

2013-12-01

We investigated the effect of high-intensity exercise on plasma creatine kinase (CK) in patients with muscular dystrophies. Fourteen patients with Becker (BMD), facioscapulohumeral (FSHD), or limb-girdle type 2 (LGMD2) muscular dystrophy, and 8 healthy subjects performed 5 cycling tests: an incremental max test, and tests at 65%, 75%, 85%, and 95% of maximal oxygen uptake (VO2max ). Heart rate and oxygen consumption were measured during the tests, and plasma CK was measured before, immediately after, and 24 hours after exercise. All subjects were able to perform high-intensity exercise at the different levels. In patients with LGMD2 and FSHD, CK normalized 24 hours after exercise compared with the pre-exercise value, whereas those with BMD and healthy controls had elevated CK values 24 hours after exercise. The findings suggest that high-intensity exercise is generally well tolerated in patients with LGMD2 and FSHD, whereas those with BMD may be more prone to exercise-induced damage. Copyright © 2013 Wiley Periodicals, Inc.

Could the two-minute step test be an alternative to the six-minute walk test for patients with systolic heart failure?

PubMed

Węgrzynowska-Teodorczyk, Kinga; Mozdzanowska, Dagmara; Josiak, Krystian; Siennicka, Agnieszka; Nowakowska, Katarzyna; Banasiak, Waldemar; Jankowska, Ewa A; Ponikowski, Piotr; Woźniewski, Marek

2016-08-01

The consequence of exercise intolerance for patients with heart failure is the difficulty climbing stairs. The two-minute step test is a test that reflects the activity of climbing stairs. The aim of the study design is to evaluate the applicability of the two-minute step test in an assessment of exercise tolerance in patients with heart failure and the association between the six-minute walk test and the two-minute step test. Participants in this study were 168 men with systolic heart failure (New York Heart Association (NYHA) class I-IV). In the study we used the two-minute step test, the six-minute walk test, the cardiopulmonary exercise test and isometric dynamometer armchair. Patients who performed more steps during the two-minute step test covered a longer distance during the six-minute walk test (r = 0.45). The quadriceps strength was correlated with the two-minute step test and the six-minute walk test (r = 0.61 and r = 0.48). The greater number of steps performed during the two-minute step test was associated with higher values of peak oxygen consumption (r = 0.33), ventilatory response to exercise slope (r = -0.17) and longer time of exercise during the cardiopulmonary exercise test (r = 0.34). Fatigue and leg fatigue were greater after the two-minute step test than the six-minute walk test whereas dyspnoea and blood pressure responses were similar. The two-minute step test is well tolerated by patients with heart failure and may thus be considered as an alternative for the six-minute walk test. © The European Society of Cardiology 2016.

Fibroblast growth factor 21 is required for beneficial effects of exercise during chronic high-fat feeding.

PubMed

Loyd, Christine; Magrisso, I Jack; Haas, Michael; Balusu, Sowmya; Krishna, Radha; Itoh, Nobuyuki; Sandoval, Darleen A; Perez-Tilve, Diego; Obici, Silvana; Habegger, Kirk M

2016-09-01

Exercise is an effective therapy against the metabolic syndrome. However, the molecular pathways underlying the advantageous effects of exercise are elusive. Glucagon receptor signaling is essential for exercise benefits, and recent evidence indicates that a downstream effector of glucagon, fibroblast growth factor 21 (FGF21), is implicated in this response. Therefore, we tested the hypothesis that FGF21 action is necessary in mediating metabolic effects of exercise. We utilized acute exhaustive treadmill exercise in Wistar rats to identify a putative, concomitant increase in plasma glucagon and FGF21 with the increase in glucose and lactate following exercise. To test the necessity of FGF21 action in the exercise response, we exposed FGF21 congenitally deficient mice (Fgf21(-/-)) and their wild-type (Wt) littermates to chronic high-fat (HF) feeding and inoperable (sedentary) or operable (exercise) voluntary running wheels. Physiological tests were performed to assess the role of FGF21 in the beneficial effect of exercise on glucose metabolism. Wt and Fgf21(-/-) littermates exhibited similar running behavior, and exercise was effective in suppressing weight and fat mass gain and dyslipidemia independently of genotype. However, exercise failed to positively affect hepatic triglyceride content and glucose tolerance in HF diet-fed Fgf21(-/-) mice. Furthermore, Fgf21(-/-) mice exhibited an impaired adaptation to exercise training, including reduced AMP-activated protein kinase activity in skeletal muscle. This study demonstrates that FGF21 action is necessary to achieve the full metabolic benefits of exercise during chronic HF feeding. Copyright © 2016 the American Physiological Society.

Fibroblast growth factor 21 is required for beneficial effects of exercise during chronic high-fat feeding

PubMed Central

Loyd, Christine; Magrisso, I. Jack; Haas, Michael; Balusu, Sowmya; Krishna, Radha; Itoh, Nobuyuki; Sandoval, Darleen A.; Perez-Tilve, Diego; Obici, Silvana

2016-01-01

Exercise is an effective therapy against the metabolic syndrome. However, the molecular pathways underlying the advantageous effects of exercise are elusive. Glucagon receptor signaling is essential for exercise benefits, and recent evidence indicates that a downstream effector of glucagon, fibroblast growth factor 21 (FGF21), is implicated in this response. Therefore, we tested the hypothesis that FGF21 action is necessary in mediating metabolic effects of exercise. We utilized acute exhaustive treadmill exercise in Wistar rats to identify a putative, concomitant increase in plasma glucagon and FGF21 with the increase in glucose and lactate following exercise. To test the necessity of FGF21 action in the exercise response, we exposed FGF21 congenitally deficient mice (Fgf21−/−) and their wild-type (Wt) littermates to chronic high-fat (HF) feeding and inoperable (sedentary) or operable (exercise) voluntary running wheels. Physiological tests were performed to assess the role of FGF21 in the beneficial effect of exercise on glucose metabolism. Wt and Fgf21−/− littermates exhibited similar running behavior, and exercise was effective in suppressing weight and fat mass gain and dyslipidemia independently of genotype. However, exercise failed to positively affect hepatic triglyceride content and glucose tolerance in HF diet-fed Fgf21−/− mice. Furthermore, Fgf21−/− mice exhibited an impaired adaptation to exercise training, including reduced AMP-activated protein kinase activity in skeletal muscle. This study demonstrates that FGF21 action is necessary to achieve the full metabolic benefits of exercise during chronic HF feeding. PMID:27445299

The effects of a moisture-wicking fabric shirt on the physiological and perceptual responses during acute exercise in the heat.

PubMed

De Sousa, Justin; Cheatham, Christopher; Wittbrodt, Matthew

2014-11-01

This study investigated the effects that a form fitted, moisture-wicking fabric shirt, promoted to have improved evaporative and ventilation properties, has on the physiological and perceptual responses during exercise in the heat. Ten healthy male participants completed two heat stress tests consisting of 45 min of exercise (50% VO2peak) in a hot environment (33 °C, 60% RH). One heat stress test was conducted with the participant wearing a 100% cotton short sleeved t-shirt and the other heat stress test was conducted with the participant wearing a short sleeved synthetic shirt (81% polyester and 19% elastane). Rectal temperature was significantly lower (P < 0.05) in the synthetic condition during the last 15 min of exercise. Furthermore, the synthetic polyester shirt retained less sweat (P < 0.05). As exercise duration increases, the ventilation and evaporation properties of the synthetic garment may prove beneficial in the preservation of body temperature during exercise in the heat. Copyright © 2014 Elsevier Ltd and The Ergonomics Society. All rights reserved.

Naloxone decreases the inhibitory effect of alprazolam on the release of adrenocorticotropin/cortisol induced by physical exercise in man.

PubMed

Coiro, Vittorio; Volpi, Riccardo; Casti, Amos; Maffei, Maria Ludovica; Stella, Adriano; Volta, Elio; Chiodera, Paolo

2011-06-01

• Alprazolam (ALP), a benzodiazepine activating GABAergic receptors, is involved in ACTH secretion. • This study demonstrates a partial opioid influence in the inhibitory effect of ALP on the release of ACTH/cortisol during physical exercise. To establish the possible involvement of alprazolam (ALP) and/or opiates in the mechanism underlying the ACTH/cortisol response to physical exercise. Tests were carried out under basal conditions (exercise control test), exercise plus ALP (50 µg at time -90 min), naloxone (10 mg at time 0) or ALP plus naloxone. Plasma ACTH and serum cortisol concentrations were evaluated in blood samples taken before, during and after the bicycle ergometer tests. ACTH and cortisol concentrations rose significantly after physical exercise. Maximum peak at time 15 min (P ≤ 0.01 vs. baseline) for ACTH and at time 30 min (P ≤ 0.01 vs. baseline) for cortisol. In the presence of naloxone, the ACTH and cortisol responses were significantly increased (maximum peak at time 20 min, P ≤ 0.02 vs. control test for ACTH, and at time 30 min (P ≤ 0.01 vs. baseline) for cortisol) whereas they were abolished by ALP. When ALP and naloxone were given together, the inhibitory effect of ALP was partial. These data demonstrate an inhibitory effect of ALP in the regulation of the ACTH/cortisol response to physical exercise in man and suggest that GABAergic receptor activating benzodiazepines and opioids interact in the neuroendocrine secretion of ACTH/cortisol. © 2011 The Authors. British Journal of Clinical Pharmacology © 2011 The British Pharmacological Society.

Acetylsalicylic acid inhibits the pituitary response to exercise-related stress in humans.

PubMed

Di Luigi, L; Guidetti, L; Romanelli, F; Baldari, C; Conte, D

2001-12-01

Prostaglandins (PGs) modulate the activity of the hypothalamus-pituitary axis, and pituitary hormones are largely involved in the physiological responses to exercise. The purpose of this study was to analyze the effects of acetylsalicylic acid (ASA), an inhibitor of PGs synthesis, in the pituitary responses to physical stress in humans. Adrenocorticotropin (ACTH), beta-endorphin, cortisol, growth hormone (GH), and prolactin (PRL) responses to exercise were evaluated after administration of either placebo or ASA. Blood samples for hormone evaluations before (-30, -15, and 0 pre) and after (0 post, +15, +30, +45, +60, and +90 min) a 30-min treadmill exercise (75% of .VO(2max)) were taken from 12 male athletes during two exercise trials. One tablet of ASA (800 mg), or placebo, was administered two times daily for 3 d before and on the morning of each exercise-test. The results clearly show that, compared with placebo, ASA ingestion significantly blunted the increased serum ACTH, beta-endorphin, cortisol, and GH levels before exercise (anticipatory response) and was associated with reduced cortisol concentrations after exercise. Furthermore, although no differences in the GH response to exercise were shown, a significantly reduced total PRL response to stress condition was observed after ASA. ASA influences ACTH, beta-endorphin, cortisol, GH, and PRL responses to exercise-related stress in humans (preexercise activation/exercise-linked response). Even though it is not possible to exclude direct action for ASA, our data indirectly confirm a role of PGs in these responses. We have to further evaluate the nature of the preexercise endocrine activation and, because of the large use of anti-inflammatory drugs in athletes, whether the interaction between ASA and hormones might positively or negatively influence health status, performance, and/or recovery.

Blood flow dynamics in heart failure

NASA Technical Reports Server (NTRS)

Shoemaker, J. K.; Naylor, H. L.; Hogeman, C. S.; Sinoway, L. I.

1999-01-01

BACKGROUND: Exercise intolerance in heart failure (HF) may be due to inadequate vasodilation, augmented vasoconstriction, and/or altered muscle metabolic responses that lead to fatigue. METHODS AND RESULTS: Vascular and metabolic responses to rhythmic forearm exercise were tested in 9 HF patients and 9 control subjects (CTL) during 2 protocols designed to examine the effect of HF on the time course of oxygen delivery versus uptake (protocol 1) and on vasoconstriction during exercise with 50 mm Hg pressure about the forearm to evoke a metaboreflex (protocol 2). In protocol 1, venous lactate and H+ were greater at 4 minutes of exercise in HF versus CTL (P<0.05) despite similar blood flow and oxygen uptake responses. In protocol 2, mean arterial pressure increased similarly in each group during ischemic exercise. In CTL, forearm blood flow and vascular conductance were similar at the end of ischemic and ambient exercise. In HF, forearm blood flow and vascular conductance were reduced during ischemic exercise compared with the ambient trial. CONCLUSIONS: Intrinsic differences in skeletal muscle metabolism, not vasodilatory dynamics, must account for the augmented glycolytic metabolic responses to moderate-intensity exercise in class II and III HF. The inability to increase forearm vascular conductance during ischemic handgrip exercise, despite a normal pressor response, suggests that enhanced vasoconstriction of strenuously exercising skeletal muscle contributes to exertional fatigue in HF.

Reflective and Non-conscious Responses to Exercise Images

PubMed Central

Cope, Kathryn; Vandelanotte, Corneel; Short, Camille E.; Conroy, David E.; Rhodes, Ryan E.; Jackson, Ben; Dimmock, James A.; Rebar, Amanda L.

2018-01-01

Images portraying exercise are commonly used to promote exercise behavior and to measure automatic associations of exercise (e.g., via implicit association tests). The effectiveness of these promotion efforts and the validity of measurement techniques partially rely on the untested assumption that the images being used are perceived by the general public as portrayals of exercise that is pleasant and motivating. The aim of this study was to investigate how content of images impacted people's automatic and reflective evaluations of exercise images. Participants (N = 90) completed a response time categorization task (similar to the implicit association test) to capture how automatically people perceived each image as relevant to Exercise or Not exercise. Participants also self-reported their evaluations of the images using visual analog scales with the anchors: Exercise/Not exercise, Does not motivate me to exercise/Motivates me to exercise, Pleasant/Unpleasant, and Energizing/Deactivating. People tended to more strongly automatically associate images with exercise if the images were of an outdoor setting, presented sport (as opposed to active labor or gym-based) activities, and included young (as opposed to middle-aged) adults. People tended to reflectively find images of young adults more motivating and relevant to exercise than images of older adults. The content of exercise images is an often overlooked source of systematic variability that may impact measurement validity and intervention effectiveness. PMID:29375419

Reflective and Non-conscious Responses to Exercise Images.

PubMed

Cope, Kathryn; Vandelanotte, Corneel; Short, Camille E; Conroy, David E; Rhodes, Ryan E; Jackson, Ben; Dimmock, James A; Rebar, Amanda L

2017-01-01

Images portraying exercise are commonly used to promote exercise behavior and to measure automatic associations of exercise (e.g., via implicit association tests). The effectiveness of these promotion efforts and the validity of measurement techniques partially rely on the untested assumption that the images being used are perceived by the general public as portrayals of exercise that is pleasant and motivating. The aim of this study was to investigate how content of images impacted people's automatic and reflective evaluations of exercise images. Participants ( N = 90) completed a response time categorization task (similar to the implicit association test) to capture how automatically people perceived each image as relevant to Exercise or Not exercise . Participants also self-reported their evaluations of the images using visual analog scales with the anchors: Exercise / Not exercise, Does not motivate me to exercise / Motivates me to exercise, Pleasant / Unpleasant , and Energizing/Deactivating . People tended to more strongly automatically associate images with exercise if the images were of an outdoor setting, presented sport (as opposed to active labor or gym-based) activities, and included young (as opposed to middle-aged) adults. People tended to reflectively find images of young adults more motivating and relevant to exercise than images of older adults. The content of exercise images is an often overlooked source of systematic variability that may impact measurement validity and intervention effectiveness.

Exercise-induced hypertension among healthy firefighters-a comparison between two different definitions.

PubMed

Leiba, Adi; Baur, Dorothee M; Kales, Stefanos N

2013-01-01

Different studies have yielded conflicting results regarding the association of hypertensive response to exercise and cardiovascular morbidity. We compared two different definitions of exaggerated hypertensive response to exercise and their association with cardio-respiratory fitness in a population of healthy firefighters. We examined blood pressure response to exercise in 720 normotensive male career firefighters. Fitness was measured as peak metabolic equivalent tasks (METs) achieved during maximal exercise treadmill tests. Abnormal hypertensive response was defined either as systolic blood pressure ≥ 200 mm Hg; or alternatively, as responses falling in the upper tertile of blood pressure change from rest to exertion, divided by the maximal workload achieved. Using the simple definition of a 200 mm Hg cutoff at peak exercise less fit individuals (METs ≤ 12) were protected from an exaggerated hypertensive response (OR 0.45, 95%CI 0.30-0.67). However, using the definition of exercise-induced hypertension that corrects for maximal workload, less fit firefighters had almost twice the risk (OR 1.8, 95%CI 1.3-2.47). Blood pressure change corrected for maximal workload is better correlated with cardiorespiratory fitness. Systolic blood pressure elevation during peak exercise likely represents an adaptive response, whereas elevation out of proportion to the maximal workload may indicate insufficient vasodilation and a maladaptive response. Prospective studies are needed to best define exaggerated blood pressure response to exercise. Copyright © 2013 American Society of Hypertension. Published by Elsevier Inc. All rights reserved.

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

PubMed

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

2008-10-01

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

A single bout of resistance exercise can enhance episodic memory performance.

PubMed

Weinberg, Lisa; Hasni, Anita; Shinohara, Minoru; Duarte, Audrey

2014-11-01

Acute aerobic exercise can be beneficial to episodic memory. This benefit may occur because exercise produces a similar physiological response as physical stressors. When administered during consolidation, acute stress, both physical and psychological, consistently enhances episodic memory, particularly memory for emotional materials. Here we investigated whether a single bout of resistance exercise performed during consolidation can produce episodic memory benefits 48 h later. We used a one-leg knee extension/flexion task for the resistance exercise. To assess the physiological response to the exercise, we measured salivary alpha amylase (a biomarker of central norepinephrine), heart rate, and blood pressure. To test emotional episodic memory, we used a remember-know recognition memory paradigm with equal numbers of positive, negative, and neutral IAPS images as stimuli. The group that performed the exercise, the active group, had higher overall recognition accuracy than the group that did not exercise, the passive group. We found a robust effect of valence across groups, with better performance on emotional items as compared to neutral items and no difference between positive and negative items. This effect changed based on the physiological response to the exercise. Within the active group, participants with a high physiological response to the exercise were impaired for neutral items as compared to participants with a low physiological response to the exercise. Our results demonstrate that a single bout of resistance exercise performed during consolidation can enhance episodic memory and that the effect of valence on memory depends on the physiological response to the exercise. Copyright © 2014 Elsevier B.V. All rights reserved.

Prefrontal cortex haemodynamics and affective responses during exercise: a multi-channel near infrared spectroscopy study.

PubMed

Tempest, Gavin D; Eston, Roger G; Parfitt, Gaynor

2014-01-01

The dose-response effects of the intensity of exercise upon the potential regulation (through top-down processes) of affective (pleasure-displeasure) responses in the prefrontal cortex during an incremental exercise protocol have not been explored. This study examined the functional capacity of the prefrontal cortex (reflected by haemodynamics using near infrared spectroscopy) and affective responses during exercise at different intensities. Participants completed an incremental cycling exercise test to exhaustion. Changes (Δ) in oxygenation (O2Hb), deoxygenation (HHb), blood volume (tHb) and haemoglobin difference (HbDiff) were measured from bilateral dorsal and ventral prefrontal areas. Affective responses were measured every minute during exercise. Data were extracted at intensities standardised to: below ventilatory threshold, at ventilatory threshold, respiratory compensation point and the end of exercise. During exercise at intensities from ventilatory threshold to respiratory compensation point, ΔO2Hb, ΔHbDiff and ΔtHb were greater in mostly ventral than dorsal regions. From the respiratory compensation point to the end of exercise, ΔO2Hb remained stable and ΔHbDiff declined in dorsal regions. As the intensity increased above the ventilatory threshold, inverse associations between affective responses and oxygenation in (a) all regions of the left hemisphere and (b) lateral (dorsal and ventral) regions followed by the midline (ventral) region in the right hemisphere were observed. Differential activation patterns occur within the prefrontal cortex and are associated with affective responses during cycling exercise.

Prefrontal Cortex Haemodynamics and Affective Responses during Exercise: A Multi-Channel Near Infrared Spectroscopy Study

PubMed Central

Tempest, Gavin D.; Eston, Roger G.; Parfitt, Gaynor

2014-01-01

The dose-response effects of the intensity of exercise upon the potential regulation (through top-down processes) of affective (pleasure-displeasure) responses in the prefrontal cortex during an incremental exercise protocol have not been explored. This study examined the functional capacity of the prefrontal cortex (reflected by haemodynamics using near infrared spectroscopy) and affective responses during exercise at different intensities. Participants completed an incremental cycling exercise test to exhaustion. Changes (Δ) in oxygenation (O2Hb), deoxygenation (HHb), blood volume (tHb) and haemoglobin difference (HbDiff) were measured from bilateral dorsal and ventral prefrontal areas. Affective responses were measured every minute during exercise. Data were extracted at intensities standardised to: below ventilatory threshold, at ventilatory threshold, respiratory compensation point and the end of exercise. During exercise at intensities from ventilatory threshold to respiratory compensation point, ΔO2Hb, ΔHbDiff and ΔtHb were greater in mostly ventral than dorsal regions. From the respiratory compensation point to the end of exercise, ΔO2Hb remained stable and ΔHbDiff declined in dorsal regions. As the intensity increased above the ventilatory threshold, inverse associations between affective responses and oxygenation in (a) all regions of the left hemisphere and (b) lateral (dorsal and ventral) regions followed by the midline (ventral) region in the right hemisphere were observed. Differential activation patterns occur within the prefrontal cortex and are associated with affective responses during cycling exercise. PMID:24788166

The effects of physical fatigue and altitude on physiological, biochemical, and performance responses.

DOT National Transportation Integrated Search

1982-05-01

Twelve healthy young men were evaluated in each of four experimental conditions involving the possible combinations of two exercise conditions given prior to performance testing (1 h of heavy exercise vs. no exercise) and two altitude conditions (gro...

Exercise blood pressure and the risk of future hypertension.

PubMed

Holmqvist, L; Mortensen, L; Kanckos, C; Ljungman, C; Mehlig, K; Manhem, K

2012-12-01

The aim of this prospective cohort study was to identify which blood pressure measurement during exercise is the best predictor of future hypertension. Further we aimed to create a risk chart to facilitate the evaluation of blood pressure reaction during exercise testing. A number (n=1047) of exercise tests by bicycle ergometry, performed in 1996 and 1997 were analysed. In 2007-2008, 606 patients without hypertension at the time of the exercise test were sent a questionnaire aimed to identify current hypertension. The response rate was 58% (n=352). During the 10-12 years between exercise test and questionnaire, 23% developed hypertension. The strongest predictors of future hypertension were systolic blood pressure (SBP) before exercise (odds ratios (OR) 1.63 (1.31-2.01) for 10 mm Hg difference) in combination with the increase of SBP over time during exercise testing (OR 1.12 (1.01-1.24) steeper increase for every 1 mm Hg min(-1)). A high SBP before exercise and a steep rise in SBP over time represented a higher risk of developing hypertension. A risk chart based on SBP before exercise, increase of SBP over time and body mass index was created. SBP before exercise, maximal SBP during exercise and SBP at 100 W were significant single predictors of future hypertension and the prediction by maximal SBP was improved by adjusting for time/power at which SBP max was reached during exercise testing. Recovery ratio (maximal SBP/SBP 4 min after exercise) was not predictive of future hypertension.

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.

Exercise preconditioning improves behavioral functions following transient cerebral ischemia induced by 4-vessel occlusion (4-VO) in rats.

PubMed

Tahamtan, Mahshid; Allahtavakoli, Mohammad; Abbasnejad, Mehdi; Roohbakhsh, Ali; Taghipour, Zahra; Taghavi, Mohsen; Khodadadi, Hassan; Shamsizadeh, Ali

2013-12-01

There is evidence that exercise decreases ischemia/reperfusion injury in rats. Since behavioral deficits are the main outcome in patients after stroke, our study was designed to investigate whether exercise preconditioning improves the acute behavioral functions and also brain inflammatory injury following cerebral ischemia. Male rats weighing 250-300 g were randomly allocated into five experimental groups. Exercise was performed on a treadmill 30min/day for 3 weeks. Ischemia was induced by 4-vessel occlusion method. Recognition memory was assessed by novel object recognition task (NORT) and step-through passive avoidance task. Sensorimotor function and motor movements were evaluated by adhesive removal test and ledged beam-walking test, respectively. Brain inflammatory injury was evaluated by histological assessment. In NORT, the discrimination ratio was decreased after ischemia (P < 0.05) and exercise preconditioning improved it in ischemic animals. In the passive avoidance test, a significant reduction in response latency was observed in the ischemic group. Exercise preconditioning significantly decreased the response latency in the ischemic rats (P < 0.001). In the adhesive removal test, latency to touch and remove the sticky labels from forepaw was increased following induction of ischemia (all P < 0.001) and exercise preconditioning decreased these indices compared to the ischemic group (all P < 0.001). In the ledged beam-walking test, the slip ratio was increased following ischemia (P < 0.05).  In the ischemia group, marked neuronal injury in hippocampus was observed. These neuropathological changes were attenuated by exercise preconditioning (P < 0.001). Our results showed that exercise preconditioning improves behavioral functions and maintains more viable cells in the dorsal hippocampus of the ischemic brain.

Drinking Water: Experts’ Views on How Future Federal Funding Can Best Be Spent to Improve Security

DTIC Science & Technology

2003-10-01

training to support, among other things, simulation exercises to provide responders with experience in carrying out emergency response plans; specialized...attack. These activities include, among other things, support for simulation exercises to provide responders with experience in carrying out utilities...conducting regional simulation exercises to test emergency response plans, with more than 88 percent (38 of 43) rating this as a high or highest

Cholinergic stimulation with pyridostigmine protects against exercise induced myocardial ischaemia

PubMed Central

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

2004-01-01

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

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.

75 FR 16703 - Safety Zone; Wilson Bay, Jacksonville, NC

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-02

... the safety of the general public and exercise participants from potential hazards associated with low flying helicopters and vessels participating in this multi agency exercise. DATES: Comments and related... multi agency exercise to test response capabilities of water rescue services in a mass casualty scenario...

Exercise Effects on Depressive Symptoms and Self-Worth in Overweight Children: A Randomized Controlled Trial*

PubMed Central

Petty, Karen H.; Tkacz, Joseph; Young-Hyman, Deborah; Waller, Jennifer L.

2009-01-01

Objective To test the dose–response effects of an exercise program on depressive symptoms and self-worth in children. Method Overweight, sedentary children (N = 207, 7–11 years, 58% male, 59% Black) were randomly assigned to low or high dose (20 or 40 min/day) aerobic exercise programs (13 ± 1.6 weeks), or control group. Children completed the Reynolds Child Depression Scale and Self-Perception Profile for Children at baseline and posttest. Results A dose–response benefit of exercise was detected for depressive symptoms. A race × group interaction showed only White children's global self-worth (GSW) improved. There was some evidence that increased self-worth mediated the effect on depressive symptoms. Conclusions This study shows dose–response benefits of exercise on depressive symptoms and self-worth in children. However, Blacks did not show increased GSW in response to the intervention. Results provide some support for mediation of the effect of exercise on depressive symptoms via self-worth. PMID:19223278

Aerobic exercise modulates anticipatory reward processing via the μ-opioid receptor system.

PubMed

Saanijoki, Tiina; Nummenmaa, Lauri; Tuulari, Jetro J; Tuominen, Lauri; Arponen, Eveliina; Kalliokoski, Kari K; Hirvonen, Jussi

2018-06-08

Physical exercise modulates food reward and helps control body weight. The endogenous µ-opioid receptor (MOR) system is involved in rewarding aspects of both food and physical exercise, yet interaction between endogenous opioid release following exercise and anticipatory food reward remains unresolved. Here we tested whether exercise-induced opioid release correlates with increased anticipatory reward processing in humans. We scanned 24 healthy lean men after rest and after a 1 h session of aerobic exercise with positron emission tomography (PET) using MOR-selective radioligand [ 11 C]carfentanil. After both PET scans, the subjects underwent a functional magnetic resonance imaging (fMRI) experiment where they viewed pictures of palatable versus nonpalatable foods to trigger anticipatory food reward responses. Exercise-induced changes in MOR binding in key regions of reward circuit (amygdala, thalamus, ventral and dorsal striatum, and orbitofrontal and cingulate cortices) were used to predict the changes in anticipatory reward responses in fMRI. Exercise-induced changes in MOR binding correlated negatively with the exercise-induced changes in neural anticipatory food reward responses in orbitofrontal and cingulate cortices, insula, ventral striatum, amygdala, and thalamus: higher exercise-induced opioid release predicted higher brain responses to palatable versus nonpalatable foods. We conclude that MOR activation following exercise may contribute to the considerable interindividual variation in food craving and consumption after exercise, which might promote compensatory eating and compromise weight control. © 2018 Wiley Periodicals, Inc.

Oral contraceptives modulate the muscle metaboreflex in healthy young women.

PubMed

Parmar, Hanna R; Sears, Jasmin; Molgat-Seon, Yannick; McCulloch, Cara L; McCracken, Laura A; Brown, Courtney V; Sheel, A William; Dominelli, Paolo B

2018-05-01

There are known sex differences in blood pressure regulation. The differences are related to ovarian hormones that influence β-adrenergic receptors and the transduction of muscle sympathetic nerve activity. Oral contraceptives (OC) modulate the ovarian hormonal profile in women and therefore may alter the cardiovascular response. We questioned if OC would alter the absolute pressor response to static exercise and influence the day-to-day variability of the response. Healthy men (n = 11) and women (n = 19) completed a familiarization day and 2 experimental testing days. Women were divided into those taking (W-OC, n = 10) and not taking (W-NC, n = 9) OC. Each experimental testing day involved isometric handgripping exercise, at 30% of maximal force, followed by circulatory occlusion to isolate the metaboreflex. Experimental days in men were 7-14 days apart. The first experimental testing in W-OC occurred 2-7 days after the start of the active phase of their OC. Women not taking OC were tested during the early and late follicular phase of the menstrual cycle as determined by commercial ovulation monitor. The increase in mean arterial pressure (MAP) during exercise was significantly lower in W-NC (95 ± 4 mm Hg) compared with men (114 ± 4 mm Hg) and W-OC (111 ± 3 mm Hg) (P < 0.05), with the differences preserved during circulatory occlusion. The rise in MAP was significantly correlated between the 2 testing days in men (r = 0.72, P < 0.01) and W-OC (r = 0.77, P < 0.05), but not in W-NC (r = 0.17, P = 0.67), indicating greater day-to-day variation in W-NC. In conclusion, OC modulate the exercise pressor response in women and minimize day-to-day variability in the exercise metaboreflex.

Fitness Level Modulates Intraocular Pressure Responses to Strength Exercises.

PubMed

Vera, Jesús; Jiménez, Raimundo; Redondo, Beatríz; Cárdenas, David; García-Ramos, Amador

2018-06-01

Purpose/Aim: The execution of strength exercises has demonstrated to increase the intraocular pressure (IOP) levels, and it may have a negative impact on the ocular health. We aimed to explore the influence of fitness level on the acute IOP response to strength exercises performed under different loading conditions, as well as to test whether the IOP responses differ between the bench press and jump squat when performed against the same relative loads. Forty military personnel males were divided in two subgroups (20 high-fit and 20 low-fit) based on their relative to body mass one-repetition maximum (1-RM). Participants performed an incremental loading test in the bench press and jump squat exercises, and IOP was assessed before and after each repetition by rebound tonometry. IOP increased immediately after executing both exercises (p < 0.01 in both cases), being the magnitude of the IOP increment positively and linearly associated with the increment of the load in both groups (i.e., high-fit and low-fit) and in both exercises (R 2 range: 0.81-1.00). Higher fitness level attenuated the IOP rise produced by both exercises (p < 0.01 in both cases). The bench press induced higher IOP increments than the jump squat for both groups at relative loads of ~50%1-RM and ~60%1-RM (p < 0.01 in all cases). These data indicate that IOP increases as a consequence of performing strength exercises, being the increment accentuated with the increase of the load and in the bench press compared to the jump squat exercise. Of special importance would be that the IOP responses were significantly reduced in high-fit individuals. These findings should be addressed in glaucoma patients.

Selection for intrinsic endurance modifies endocrine stress responsiveness

PubMed Central

Waters, R Parrish; Renner, Kenneth J; Summers, Cliff H; Watt, Michael L; Forster, Gina L; Koch, Lauren G; Britton, Steven L; Swallow, John G

2010-01-01

Physical exercise dampens an individual’s stress response and decreases symptoms of anxiety and depression disorders. While the extrinsic relationship of exercise and psychological state are established, their intrinsic relationship is unresolved. We investigated the potential intrinsic relationship of exercise with stress responsiveness using NIH rats bidirectionally selected for intrinsic endurance capacity. Selection resulted in two populations, one with high intrinsic endurance (high capacity runners; HCR) and one with low intrinsic endurance (low capacity runners; LCR). Animals from these populations were subjected to the elevated plus maze (EPM) and novel environment to assess levels of anxiety-like behavior, and to restraint stress to determine stress responsiveness. Pre-test plasma corticosterone levels and the response of plasma corticosterone to exposure to the EPM and restraint were analyzed using ELISA. A dexamethasone suppression test was performed to assess negative feedback tone of corticosterone release. Pre-test plasma corticosterone levels were similar between LCR and HCR, and these populations had similar behavioral and corticosterone responses to the EPM. Following restraint, HCR animals exhibited more anxiotypic behavior than LCR animals on the EPM, and exhibited an increase in plasma corticosterone following EPM and restraint that was not observed in LCR animals. HCR animals also exhibited more anxiotypic behavior in the novel environment compared to LCR animals. Plasma corticosterone levels were equally reduced in both populations following dexamethasone administration. Overall, our data suggest a positive genetic relationship between exercise endurance and stress responsiveness, which is at odds with the established extrinsic relationship of these traits. PMID:20682296

75 FR 30706 - Safety Zone; Wilson Bay, Jacksonville, NC

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-02

... the general public and exercise participants from potential hazards associated with low flying helicopters and vessels participating in this multi agency exercise. DATES: This rule is effective from 6 a.m... exercise to test response capabilities of water rescue services in a mass casualty scenario on the waters...

Cortisol levels during prolonged exercise: the influence of menstrual phase and menstrual status.

PubMed

Kanaley, J A; Boileau, R A; Bahr, J M; Misner, J E; Nelson, R A

1992-05-01

The purpose of this study was to determine the influence of menstrual phase and menstrual status on the cortisol response during 90 minutes of treadmill running at 60% VO2max. Eight eumenhorrheic athletes were tested in the early follicular (EF) (day 3-5), late follicular (LF) (day 13-15) and mid-luteal (ML) (day 22-24) phases. Six amenorrheic athletes were tested on two separate occasions. The resting cortisol levels were similar in each menstrual phase and overall a decreasing pattern of cortisol response to exercise was observed in all menstrual phases (P greater than .05). The amenorrheic athletes had a significantly greater (P less than .01) pattern of cortisol response than was observed in eumenorrheic athletes. The net increment in cortisol levels during exercise were distinctly greater (P less than .01) in amenorrheic than eumenorrheic athletes (amenorrheic: 413.8 +/- 113.1, eumenorrheic: EF: -482.8 +/- 88.3, LF: -311.8 +/- 102.1, ML: -386.3 +/- 146.2 nmol.l-1). In conclusion the cortisol levels are independent of menstrual phase. Also a larger cortisol increment is observed in amenorrheic athletes in response to prolonged submaximal exercise. The elevated cortisol levels in amenorrheics at rest and throughout exercise provides further evidence that disturbances in the hypothalamic-pituitary-adrenal function are associated with exercise-induced amenorrhea, although the site(s) of physiological disturbance have not been identified.

Ready or not: analysis of a no-notice mass vaccination field response in Philadelphia.

PubMed

Caum, Jessica; Alles, Steven

2013-12-01

Local health departments typically rely on exercises to test preparedness capacity; however, pre-scripted drills often lack the sense of urgency that a real event would engender. No-notice, unscripted exercises that challenge staff to think critically under pressure may provide a mechanism for a more realistic assessment of preparedness capacity. The very active influenza season of 2012-13 presented the Public Health Preparedness Program at the Philadelphia Department of Public Health with the opportunity to conduct an influenza vaccination clinic at a local boarding school. Program leaders used this opportunity to design a no-notice exercise to test the ability of staff to effectively coordinate an emergency field response while simultaneously delivering a real public health intervention. On the day of the exercise, staff members were given 6 hours to plan and execute a vaccination clinic without any guidance from program leaders. Best practices observed during the exercise included: (1) early identification and mitigation of rate-limiting steps, and (2) successful implementation of a previously untested high-throughput vaccination model. Although the primary intent of the exercise was to assess the ability of staff to respond to a no-notice event, this vaccination clinic also functioned as a microcosm of a larger response, revealing several considerations related to vaccine ordering, staff resources, and throughput rates that have broader implications for public health responses to large-scale biological attacks or pandemics.

Circulatory and muscle metabolic responses to draught work compared to increasing trotting velocities.

PubMed

Gottlieb, M; Essén-Gustavsson, B; Lindholm, A; Persson, S G

1988-11-01

Circulatory and muscle metabolic responses were studied in 10 horses which all performed incremental draught work at a low trotting speed on a treadmill (D-test) and also exercise with gradually increasing velocities (S-test). Exercise was continued until the horses could no longer maintain the weights above the floor or maintain speed trotting without changing gait to a gallop. Muscle biopsies were taken from the gluteus and the semitendinosus muscles before, and immediately after, exercise. The heart rate (HR) increased linearly with both increasing draught resistance and velocity and reached mean values of 212 and 203 beats/min, respectively. Blood lactate levels increased exponentially to mean values of 12.9 and 7.9 mmol/litre in the two tests. Both HR and blood lactate levels were significantly higher at the cessation of work in the D-test compared to the S-test. The relationship between HR and blood lactate response in the S-test was similar to that in the D-test. The red cell volume was determined after a standardised exercise tolerance test and was significantly correlated both to the weightloading and to the velocity, producing a HR of 200 beats/min. The changes seen in muscle glycogen and glucose-6-phosphate were similar in the two tests, whereas significantly higher lactate levels and lower creatine phosphate and adenosine triphosphate levels were seen in the D-test compared to the S-test. It was concluded that high oxidative capacity is of importance both for fast trotting and for draught work.(ABSTRACT TRUNCATED AT 250 WORDS)

Measuring the effects of massage on exercise performance and cardiopulmonary response in children with and without heart disease: a pilot study.

PubMed

Beider, Shay; Boulanger, Karen T; Joshi, Milind; Pan, Yann Ping; Chang, Ruey-Kang R

2010-09-28

Congenital heart disease, a common and serious birth defect, affects 8 per 1000 live-born infants. Decreased exercise capacity and development of obesity is common in this population. These children may benefit from therapies, such as massage therapy, that could enhance cardiovascular and skeletal muscle function when they exercise. A pilot study conducted at the pediatric cardiology clinic of the Mattel Children's Hospital of the University of California-Los Angeles examined the safety and feasibility of measuring the effects of pre-exercise massage on exercise performance and cardiopulmonary response in children with and without heart disease. SIXTEEN CHILDREN (MEAN AGE: 9.2 ± 2.2 years) participated in the study. Ten participants had various forms of heart disease, and six children were healthy. A female certified massage therapist with specialized training in pediatric massage provided a 30-minute massage to the participants. Using a standard protocol, each participant underwent two exercise tests: one test with and one without pre-exercise massage. Heart rate, blood pressure, and oxygen uptake (VO(2)) were measured in the participants. All recruited participants completed the study. No adverse events occurred during any of the exercise tests or massage sessions. Measurements during exercise with or without a preceding massage were compared, and the pre-exercise massage condition yielded a significantly higher heart rate and higher minute ventilation. Measurements during exercise in children with heart disease and in healthy participants showed no significant differences in peak heart rate, blood pressure, peak VO(2), peak work rate, minute ventilation, or respiratory quotient. In this study, peak heart rate, peak VO(2), and peak minute ventilation were higher when children received a massage before exercise testing. Larger studies will be needed to investigate the strength of this finding. Future studies should include measurements of anxiety and psychological factors in addition to cardiopulmonary measures.

Aldosterone response to angiotensin II during hypoxemia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Colice, G.L.; Ramirez, G.

1986-07-01

Exercise stimulates the renin-angiotensin-aldosterone system (RAAS). However, increases in plasma aldosterone concentrations (PAC) are suppressed when exercise is performed at high altitude or under hypoxemic conditions. As the angiotensin-II response to high-altitude exercise is normal, it is speculated that an inhibitor, discharged during hypoxemia, acted to suppress angiotensin-II-mediated aldosterone release. A study was conducted to test this hypothesis, taking into account the measurement of the aldosterone response to exogenous angiotensin II during normoxemia and hypoxemia. It was found that the dose-response curve of PAC to angiotensin II was not significantly inhibited by the considered model of hypoxemia. The hypoxemia-mediated releasemore » of an angiotensin II inhibitor does, therefore, not explain the previous observations of PAC suppression during hypoxemic exercise. 28 references.« less

Sleep Recovery from Physical Exercise: A New Understanding of Brain Responses to Stress

DTIC Science & Technology

2001-03-01

34 response and a "general" stress response. These responses ("diachronic" or "synchronic") are also examined in relation to chronobiological ...34 stress reaction, as evidenced by an increased heart rate during night sleep (43). These results can also be interpreted in terms of chronobiology ...TROPICAL CLIMATE The effects of progressive training were analysed in sedentary subjects (13), using a square wave endurance exercise test performed

Effect of Caffeine on Oxidative Stress During Maximum Incremental Exercise

PubMed Central

Olcina, Guillermo J.; Muñoz, Diego; Timón, Rafael; Caballero, M. Jesús; Maynar, Juan I.; Córdova, Alfredo; Maynar, Marcos

2006-01-01

Caffeine (1,3,7-trimethylxanthine) is an habitual substance present in a wide variety of beverages and in chocolate-based foods and it is also used as adjuvant in some drugs. The antioxidant ability of caffeine has been reported in contrast with its pro- oxidant effects derived from its action mechanism such as the systemic release of catecholamines. The aim of this work was to evaluate the effect of caffeine on exercise oxidative stress, measuring plasma vitamins A, E, C and malonaldehyde (MDA) as markers of non enzymatic antioxidant status and lipid peroxidation respectively. Twenty young males participated in a double blind (caffeine 5mg·kg- 1 body weight or placebo) cycling test until exhaustion. In the exercise test, where caffeine was ingested prior to the test, exercise time to exhaustion, maximum heart rate, and oxygen uptake significantly increased, whereas respiratory exchange ratio (RER) decreased. Vitamins A and E decreased with exercise and vitamin C and MDA increased after both the caffeine and placebo tests but, regarding these particular variables, there were no significant differences between the two test conditions. The results obtained support the conclusion that this dose of caffeine enhances the ergospirometric response to cycling and has no effect on lipid peroxidation or on the antioxidant vitamins A, E and C. Key Points Caffeine ingestion may improve maximal aerobic performance in non trained men. Cellular oxidative damage is not altered by caffeine ingestion in maximal aerobic exercises. Antioxidant response to exercise, vitamins A, E and C, is not modified by caffeine action in maximal aerobic efforts. PMID:24357958

Cross refractoriness between sodium metabisulphite and exercise induced asthma.

PubMed Central

Pavord, I.; Lazarowicz, H.; Inchley, D.; Baldwin, D.; Knox, A.; Tattersfield, A.

1994-01-01

BACKGROUND--Exercise and inhaled sodium metabisulphite are thought to cause bronchoconstriction in asthma through different mechanisms. The response to both stimuli becomes refractory with repeat challenge. The mechanism of refractoriness is unclear, although depletion of mast cell derived mediators or neurotransmitters has been suggested. Recent studies suggest a common mechanism involving release of inhibitory prostaglandins. If this is true, exercise and sodium metabisulphite induced bronchoconstriction should show cross refractoriness. METHODS--Thirteen subjects with mild asthma and previously established exercise and sodium metabisulphite induced bronchoconstriction performed two sodium metabisulphite challenges (giving a single dose previously shown to cause a 20% fall in FEV1) on one study day, and two exercise tests on another. The second challenge proceeded after recovery (FEV1 > 95% baseline) from the first. Subjects then attended on two further occasions when an exercise test was performed after sodium metabisulphite and a sodium metabisulphite challenge after exercise. RESULTS--When expressed as the percentage reduction in the area under the change in percentage FEV1 curve over 20 minutes (AUC) the response to exercise was reduced by a mean 62.3% (95% CI 46.5% to 78.1%) following a first exercise challenge, and by 50.7% (95% CI 27.8% to 73.6%) following a sodium metabisulphite challenge. The response to a sodium metabisulphite challenge was reduced by a mean of 80.2% (95% CI 68.9% to 91.5%) when it followed a sodium metabisulphite challenge, and by 37.3% (95% CI 15.1% to 59.5%) following an exercise challenge. CONCLUSION--This study shows some cross refractoriness between exercise and sodium metabisulphite induced bronchoconstriction, in keeping with a partially shared mechanism of refractoriness. PMID:8202881

A single bout of high-intensity aerobic exercise facilitates response to paired associative stimulation and promotes sequence-specific implicit motor learning

PubMed Central

Mang, Cameron S.; Snow, Nicholas J.; Campbell, Kristin L.; Ross, Colin J. D.

2014-01-01

The objectives of the present study were to evaluate the impact of a single bout of high-intensity aerobic exercise on 1) long-term potentiation (LTP)-like neuroplasticity via response to paired associative stimulation (PAS) and 2) the temporal and spatial components of sequence-specific implicit motor learning. Additionally, relationships between exercise-induced increases in systemic brain-derived neurotrophic factor (BDNF) and response to PAS and motor learning were evaluated. Sixteen young healthy participants completed six experimental sessions, including the following: 1) rest followed by PAS; 2) aerobic exercise followed by PAS; 3) rest followed by practice of a continuous tracking (CT) task and 4) a no-exercise 24-h retention test; and 5) aerobic exercise followed by CT task practice and 6) a no-exercise 24-h retention test. The CT task included an embedded repeated sequence allowing for evaluation of sequence-specific implicit learning. Slope of motor-evoked potential recruitment curves generated with transcranial magnetic stimulation showed larger increases when PAS was preceded by aerobic exercise (59.8% increase) compared with rest (14.2% increase, P = 0.02). Time lag of CT task performance on the repeated sequence improved under the aerobic exercise condition from early (−100.8 ms) to late practice (−75.2 ms, P < 0.001) and was maintained at retention (−79.2 ms, P = 0.004) but did not change under the rest condition (P > 0.16). Systemic BDNF increased on average by 3.4-fold following aerobic exercise (P = 0.003), but the changes did not relate to neurophysiological or behavioral measures (P > 0.42). These results indicate that a single bout of high-intensity aerobic exercise can prime LTP-like neuroplasticity and promote sequence-specific implicit motor learning. PMID:25257866

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

Maximising the clinical use of exercise gaseous exchange testing in children with repaired cyanotic congenital heart defects: the development of an appropriate test strategy.

PubMed

McManus, A; Leung, M

2000-04-01

Implicit in deciding upon an exercise test strategy to elucidate cardiopulmonary function in children with congenital heart disease are appropriate application of gas exchange techniques and the significance of the data collected to the specific congenital heart disorder. Post-operative cardiopulmonary responses to exercise in cyanotic disorders are complex and, despite a large body of extant literature in paediatric patients, there has been much difficulty in achieving quality and consistency of data. Maximal oxygen uptake is widely recognised as the best single indicator of cardiopulmonary function and has therefore been the focus of most clinical exercise tests in children. Many children with various heart anomalies are able to exercise to maximum without adverse symptoms, and it is essential that test termination is based on the same criteria for these children. Choosing appropriate, valid indicators of maximum in children with congenital heart disease is beset by difficulties. Such maximal intensity exercise testing procedures have been challenged on the grounds that they do not give a good indication of cardiopulmonary function that is relevant to real life situations. Furthermore, they are prone to much interindividual variability and error in the definition of maximal exertion. Alternative strategies have been proposed which focus upon dynamic submaximal and kinetic cardiopulmonary responses, which are thought to be less dependent on maximal voluntary effort and more suited to the daily activity patterns of children. These methods are also not without problems. Variability in anaerobic threshold measurements and controversy regarding its physiological meaning have been debated. It is recommended that an appropriate cardiopulmonary exercise gas exchange test strategy, which provides clinically useful information for children with cyanotic congenital heart disease, should include both maximal and submaximal data. The inclusion of oxygen uptake kinetics and ventilatory data are encouraged, since they may allow the distinction between a pulmonary, cardiovascular or inactivity related exercise limitation.

Hemodynamic changes after static and dynamic exercises and treadmill stress test; different patterns in patients with primary benign exertional headache?

PubMed

Kordi, Ramin; Mazaheri, Reza; Rostami, Mohsen; Mansournia, Mohammad Ali

2012-01-01

The pathophysiology of primary benign exertional headache (EH) is not still clearly defined. Some researchers have suggested an impaired vascular response as the etiology of this disorder. In this study we investigated whether there are any differences in blood pressure (BP) and heart rate (HR) of the subjects in course of the static and dynamic exercises and the treadmill stress test between those with and without EH. From university students, 22 patients with EH (mean age: 19.8 ± 2.10, Female to Male: 7:15) and 20 normal subjects (mean age: 19.3 ± 1.97, Female: Male: 8:12) were recruited. All the subjects performed the static and dynamic exercises at 30 and 20 percent of the maximal voluntary contraction (MVC) and Bruce treadmill stress test according to the standard protocols. HR and BP of all the cases at the baseline and during and immediately after each test were measured. No significant difference was found between the mean rise of HR, systolic and diastolic BP of the subjects with and without EH in static and dynamic exercises and also treadmill stress test. It seems that between those with and without EH, there is no significant difference in rise of HR and BP response to static and dynamic exercises and treadmill stress test. Further studies are required to find the pathophysiology and risk factors of EH.

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

Measurement properties of maximal cardiopulmonary exercise tests protocols in persons after stroke: A systematic review.

PubMed

Wittink, Harriet; Verschuren, Olaf; Terwee, Caroline; de Groot, Janke; Kwakkel, Gert; van de Port, Ingrid

2017-11-21

To systematically review and critically appraise the literature on measurement properties of cardiopulmonary exercise test protocols for measuring aerobic capacity, VO2max, in persons after stroke. PubMed, Embase and Cinahl were searched from inception up to 15 June 2016. A total of 9 studies were identified reporting on 9 different cardiopulmonary exercise test protocols. VO2max measured with cardiopulmonary exercise test and open spirometry was the construct of interest. The target population was adult persons after stroke. We included all studies that evaluated reliability, measurement error, criterion validity, content validity, hypothesis testing and/or responsiveness of cardiopulmonary exercise test protocols. Two researchers independently screened the literature, assessed methodological quality using the COnsensus-based Standards for the selection of health Measurement INstruments checklist and extracted data on measurement properties of cardiopulmonary exercise test protocols. Most studies reported on only one measurement property. Best-evidence synthesis was derived taking into account the methodological quality of the studies, the results and the consistency of the results. No judgement could be made on which protocol is "best" for measuring VO2max in persons after stroke due to lack of high-quality studies on the measurement properties of the cardiopulmonary exercise test.

Adolescent voluntary exercise attenuated hippocampal innate immunity responses and depressive-like behaviors following maternal separation stress in male rats.

PubMed

Sadeghi, Mahsa; Peeri, Maghsoud; Hosseini, Mir-Jamal

2016-09-01

Early life stressful events have detrimental effects on the brain and behavior, which are associated with the development of depression. Immune-inflammatory responses have been reported to contribute in the pathophysiology of depression. Many studies have reported on the beneficial effects of exercise against stress. However, underlying mechanisms through which exercise exerts its effects were poorly studied. Therefore, it applied maternal separation (MS), as a valid animal model of early-life adversity, in rats from postnatal day (PND) 2 to 14 for 180min per day. At PND 28, male Wistar albino rats were subjected to 5 experimental groups; 1) controls 2) MS rats 3) MS rats treated with fluoxetine 5mg/kg to PND 60, 4) MS rats that were subjected to voluntary running wheel (RW) exercise and 5) MS rats that were subjected to mandatory treadmill (TM) exercise until adulthood. At PND 60, depressive-like behaviors were assessed by using forced swimming test (FST), splash test, and sucrose preference test (SPT). Our results revealed that depressive-like behaviors following MS stress were associated with an increase in expression of toll-like receptor 4 (Tlr-4) and its main signaling protein, Myd88, in the hippocampal formation. Also, we found that voluntary (and not mandatory) physical exercise during adolescence is protected against depressant effects of early-life stress at least partly through mitigating the innate immune responses in the hippocampus. Copyright © 2016. Published by Elsevier Inc.

Sinusoidal high-intensity exercise does not elicit ventilatory limitation in chronic obstructive pulmonary disease.

PubMed

Porszasz, Janos; Rambod, Mehdi; van der Vaart, Hester; Rossiter, Harry B; Ma, Shuyi; Kiledjian, Rafi; Casaburi, Richard

2013-06-01

During exercise at critical power (CP) in chronic obstructive pulmonary disease (COPD) patients, ventilation approaches its maximum. As a result of the slow ventilatory dynamics in COPD, ventilatory limitation during supramaximal exercise might be escaped using rapid sinusoidal forcing. Nine COPD patients [age, 60.2 ± 6.9 years; forced expiratory volume in the first second (FEV(1)), 42 ± 17% of predicted; and FEV(1)/FVC, 39 ± 12%] underwent an incremental cycle ergometer test and then four constant work rate cycle ergometer tests; tolerable duration (t(lim)) was recorded. Critical power was determined from constant work rate testing by linear regression of work rate versus 1/t(lim). Patients then completed fast (FS; 60 s period) and slow (SS; 360 s period) sinusoidally fluctuating exercise tests with mean work rate at CP and peak at 120% of peak incremental test work rate, and one additional test at CP; each for a 20 min target. The value of t(lim) did not differ between CP (19.8 ± 0.6 min) and FS (19.0 ± 2.5 min), but was shorter in SS (13.2 ± 4.2 min; P < 0.05). The sinusoidal ventilatory amplitude was minimal (37.4 ± 34.9 ml min(-1) W(-1)) during FS but much larger during SS (189.6 ± 120.4 ml min(-1) W(-1)). The total ventilatory response in SS reached 110 ± 8.0% of the incremental test peak, suggesting ventilatory limitation. Slow components in ventilation during constant work rate and FS exercises were detected in most subjects and contributed appreciably to the total response asymptote. The SS exercise was associated with higher mid-exercise lactate concentrations (5.2 ± 1.7, 7.6 ± 1.7 and 4.5 ± 1.3 mmol l(-1) in FS, SS and CP). Large-amplitude, rapid sinusoidal fluctuation in work rate yields little fluctuation in ventilation despite reaching 120% of the incremental test peak work rate. This high-intensity exercise strategy might be suitable for programmes of rehabilitative exercise training in COPD.

Acute aerobic exercise helps overcome emotion regulation deficits.

PubMed

Bernstein, Emily E; McNally, Richard J

2017-06-01

Although colloquial wisdom and some studies suggest an association between regular aerobic exercise and emotional well-being, the nature of this link remains poorly understood. We hypothesised that aerobic exercise may change the way people respond to their emotions. Specifically, we tested whether individuals experiencing difficulties with emotion regulation would benefit from a previous session of exercise and show swifter recovery than their counterparts who did not exercise. Participants (N = 80) completed measures of emotion response tendencies, mood, and anxiety, and were randomly assigned to either stretch or jog for 30 minutes. All participants then underwent the same negative and positive mood inductions, and reported their emotional responses. Analyses showed that more perceived difficulty generating regulatory strategies and engaging in goal-directed behaviours after the negative mood induction predicted more intense and persistent negative affect in response to the stressor, as would be expected. Interactions revealed that aerobic exercise attenuated these effects. Moderate aerobic exercise may help attenuate negative emotions for participants initially experiencing regulatory difficulties. This study contributes to the literature on aerobic exercise's therapeutic effects with experimental data, specifically in the realm of emotional processing.

Acute exercise performed close to the anaerobic threshold improves cognitive performance in elderly females.

PubMed

Córdova, C; Silva, V C; Moraes, C F; Simões, H G; Nóbrega, O T

2009-05-01

The objective of the present study was to compare the effect of acute exercise performed at different intensities in relation to the anaerobic threshold (AT) on abilities requiring control of executive functions or alertness in physically active elderly females. Forty-eight physically active elderly females (63.8 +/- 4.6 years old) were assigned to one of four groups by drawing lots: control group without exercise or trial groups with exercise performed at 60, 90, or 110% of AT (watts) and submitted to 5 cognitive tests before and after exercise. Following cognitive pretesting, an incremental cycle ergometer test was conducted to determine AT using a fixed blood lactate concentration of 3.5 mmol/L as cutoff. Acute exercise executed at 90% of AT resulted in significant (P < 0.05, ANOVA) improvement in the performance of executive functions when compared to control in 3 of 5 tests (verbal fluency, Tower of Hanoi test (number of movements), and Trail Making test B). Exercising at 60% of AT did not improve results of any tests for executive functions, whereas exercise executed at 110% of AT only improved the performance in one of these tests (verbal fluency) compared to control. Women from all trial groups exhibited a remarkable reduction in the Simple Response Time (alertness) test (P = 0.001). Thus, physical exercise performed close to AT is more effective to improve cognitive processing of older women even if conducted acutely, and using a customized exercise prescription based on the anaerobic threshold should optimize the beneficial effects.

Changes in extracellular muscle volume affect heart rate and blood pressure responses to static exercise

NASA Astrophysics Data System (ADS)

Baum, K.; Essfeld, D.; Stegemann, J.

To investigate the effect of μg-induced peripheral extracellular fluid reductions on heart rate and blood pressure during isometric exercise, six healthy male subjects performed three calf ergometer test with different extracellular volumes of working muscles. In all tests, body positions during exercise were identical (supine with the knee joint flexed to 900). After a pre-exercise period of 25 min, during which calf volumes were manipulated, subjects had to counteract an external force of 180 N for 5 min. During the pre-exercise period three different protocols were applied. Test A: Subjects rested in the exercise position; test B: Body position was the same as in A but calf volume was increased by venous congestion (cuffs inflated to 80 mm Hg); test C: Calf volumes were decreased by a negative hydrostatic pressure (calves about 40 cm above heart level with the subjects supine). To clamp the changed calf volumes in tests B and C, cuffs were inflated to 300 mm Hg 5 min before the onset of exercise. This occlusion was maintained until termination of exercise. Compared to tests A and B, the reduced volume of test C led to significant increases in heart rate and blood pressure during exercise. Oxygen uptake did not exceed resting levels in B and C until cuffs were deflated, indicating that exclusively calf muscles contributed to the neurogenic peripheral drive. It is concluded that changes in extracellular muscle volume have to be taken into account when comparing heart rate and blood pressure during lg- and μg- exercise.

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

PubMed

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

2015-07-01

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

Aerobic exercise modulation of mental stress-induced responses in cultured endothelial progenitor cells from healthy and metabolic syndrome subjects.

PubMed

Rocha, Natalia G; Sales, Allan R K; Miranda, Renan L; Silva, Mayra S; Silva, Jemima F R; Silva, Bruno M; Santos, Aline A; Nóbrega, Antonio C L

2015-02-15

Numerous studies have demonstrated that exercise acutely prevents the reduction in flow-mediated dilation induced by mental stress in subjects with metabolic syndrome (MetS). However, it is unknown whether a similar effect occurs in endothelial progenitors cells (EPCs). This study investigated whether exercise protects from the deleterious effect of mental stress on cultured EPCs in healthy subjects and those with MetS. Ten healthy subjects (aged 31±2) and ten subjects with MetS (aged 36±2) were enrolled. Subjects underwent a mental stress test, followed immediately by either 40 min of leg cycling or rest across two randomized sessions: mental stress+non-exercise control (MS) and mental stress+exercise (MS+EXE). The Stroop Color-Word Test was used to elicit mental stress. Blood samples were drawn at baseline and following sessions to isolate mononuclear cells. These cells were cultured in fibronectin-coated plates for seven days, and EPCs were identified by immunofluorescence (acLDL(+)/ UEA-I Lectin(+)). All subjects presented similar increases in mean blood pressure and heart rate during the mental stress test (P<0.01) in both the MS and MS+EXE sessions. Number of EPCs was not different between groups at baseline in both sessions (P>0.05). The EPC response to MS and MS+EXE was increased in healthy subjects, whereas it was decreased in subjects with MetS (P<0.04). In healthy subjects, the EPC response to MS+EXE was greater than the response to MS alone (P=0.03). An exercise session increased EPCs in healthy subjects but did not prevent the EPC reduction induced by mental stress among subjects with MetS. © 2015.

Comparison of cardiorespiratory responses during aquatic and land treadmill exercise in patients with coronary artery disease.

PubMed

Choi, Jun Hwan; Kim, Bo Ryun; Joo, Seung Jae; Han, Eun Young; Kim, Song Yi; Kim, Sun Mi; Lee, So Young; Yoon, Ho Min

2015-01-01

To investigate cardiorespiratory responses during exercise stress tests using an aquatic treadmill and a land-based treadmill in patients with coronary artery disease (CAD). Twenty-one stable CAD patients were enrolled. All patients participated in 2 symptom-limited incremental exercise tests, using both an aquatic and a land treadmill. For the aquatic treadmill protocol, patients were submerged to the upper waist in 28°C water. The treadmill speed started at 2.0 km/h and increased 0.5 km/h every minute thereafter. For the land treadmill protocol, the speed and gradient were started at 2.4 km/h and 1.5%, respectively. The speed was increased by 0.3 km/h and grade by 1% every minute thereafter. Oxygen consumption ((Equation is included in full-text article.)O2), heart rate (HR), and respiratory exchange ratio were measured continuously and peak values recorded. Rating of perceived exertion, percentage of age-predicted maximal HR, and total exercise duration were also recorded. Peak cardiorespiratory responses during both protocols were compared. The peak (Equation is included in full-text article.)O2 and peak HR did not show any significant differences. The peak respiratory exchange ratio was significantly greater using the land treadmill than the aquatic treadmill protocol. Rating of perceived exertion, age-predicted maximal HR percentage, and total exercise duration were similar for both protocols. There was a significant linear relationship between HR and (Equation is included in full-text article.)O2 with both protocols. This study demonstrated that aquatic treadmill exercise elicits similar peak cardiorespiratory responses compared with land treadmill exercise, suggesting that aquatic treadmill exercise may be effective for CAD patients in cardiac rehabilitation.

Inflight exercise affects stand test responses after space flight

NASA Technical Reports Server (NTRS)

Lee, S. M.; Moore, A. D. Jr; Fritsch-Yelle, J. M.; Greenisen, M. C.; Schneider, S. M.

1999-01-01

PURPOSE: The purpose of this study was to determine whether exercise performed by Space Shuttle crew members during short-duration space flights (9-16 d) affects the heart rate (HR) and blood pressure (BP) responses to standing within 2-4 h of landing. METHODS: Thirty crew members performed self-selected inflight exercise and maintained exercise logs to monitor their exercise intensity and duration. Two subjects participated in this investigation during two different flights. A 10-min stand test, preceded by at least 6 min of quiet supine rest, was completed 10-15 d before launch (PRE) and within 4 h of landing (POST). Based upon their inflight exercise records, subjects were grouped as either high (HIex: > or = 3 times/week, HR > or = 70% HRmax, > or = 20 min/session, N = 11), medium (MEDex: > or = 3 times/week, HR < 70% HRmax, > or = 20 min/session, N = 10), or low (LOex: < or = 3 times/week, HR and duration variable, N = 11) exercisers. HR and BP responses to standing were compared between groups (ANOVA, P < or = 0.05). RESULTS: There were no PRE differences between the groups in supine or standing HR and BP. Although POST supine HR was similar to PRE, all groups had an increased standing HR compared with PRE. The increase in HR upon standing was significantly greater after flight in the LOex group (36 +/- 5 bpm) compared with HIex or MEDex groups (25 +/- 1 bpm; 22 +/- 2 bpm). Similarly, the decrease in pulse pressure (PP) from supine to standing was unchanged after space flight in the MEDex and HIex groups but was significantly greater in the LOex group (PRE: -9 +/- 3; POST: -19 +/- 4 mm Hg). CONCLUSIONS: Thus, moderate to high levels of inflight exercise attenuated HR and PP responses to standing after space flight.

Leptin, gastrointestinal and stress hormones in response to exercise in fasted or fed subjects and before or after blood donation.

PubMed

Sliwowski, Z; Lorens, K; Konturek, S J; Bielanski, W; Zoładź, J A

2001-03-01

Leptin, an ob gene product of adipocytes, plays a key role in the control of food intake and energy expenditure but little is known about leptin response to strenuous exercise in fasted and fed subjects or before and after blood donation. This study was designed to determine the immediate effects of strenuous exercise in healthy volunteers under fasting or fed conditions and before and one day after blood donation (450 ml) on plasma levels of leptin and gut hormones [gastrin, cholecystokinin (CCK), pancreatic polypeptide (PP) and insulin], as well as on "stress" hormones (cortisol, catecholamines and growth hormone. Two groups (A and B) of healthy non-smoking male volunteers were studied. All subjects performed incremental exercise tests until exhaustion (up to maximal oxygen uptake--VO2max), followed by 2 h of rest session. Group A perfomed the tests on a treadmill, while group B on a cycloergometer. In group A, one exercise was performed under fasting conditions and the second following ingestion of a standard liquid meal. In group B, one exercise test was performed as a control test and the second 24 h after blood donation (450 ml). Blood samples were withdrawn 5 min before the start of the test, at the VO2max, and 2 h after finishing the exercise. No significant change in plasma teptin were observed both immediately and 2 h after the exercise in fasted subjects, but after the meal the plasma leptin at VO2max and 2 h after the test was significantly higher, while after blood donation was significantly reduced. The postprandial rise in plasma leptin was accompanied by a marked increment in gut hormones; gastrin, CCK and PP and stress hormones such as norepinephrine, cortisol and GH. These hormonal changes could contribute to the postprandial rise in plasma leptin concentrations, while the fall of leptin after blood donation could be attributed to the inadequate response of stress hormones and autonomic nervous system to exhausting exercise. We conclude that strenuous physical exercise; 1) fails to affect plasma leptin level but when performed after meal but not after blood withdrawal it results in an increase and fall in plasma leptin, and 2) the release of gut hormones (gastrin, CCK and PP) and stress hormones (norepinephrine, cortisol, GH) increase immediately after exercise independently of feeding or blood donation and 3) following blood donation the strenuous exercise resulted in a marked reduction in the plasma leptin, cortisol and GH concentrations, possibly due to the impairment in the autonomic nervous control of these hormones.

Exercise electrocardiogram tests in manual workers with and without antibodies to Trypanosoma cruzi: a population-based study.

PubMed

Zicker, F; Zicker, E M; Oliveira, J J; Netto, J C; Oliveira, R M; Smith, P G

1990-01-01

Blood pressure, heart rate and electrocardiographic responses to exercise were compared in a group of 125 subjects with antibodies to Trypanosoma cruzi and in 153 seronegative subjects, randomly selected from persons with no evidence of heart disease in a resting electrocardiogram during a cross-sectional survey among apparently healthy manual workers. The mean heart rates and diastolic and systolic blood pressures of those in each group did not differ statistically at different phases of the exercise test and there was no evidence of a difference in physical fitness between those in the 2 groups. An abnormal test was recorded in 26.2% of seropositive, and in 16.1% of seronegative, subjects (odds ratio adjusted for age, sex and body mass index [OR] = 2.0, 95% confidence interval [95% CI] = 1.1-3.8). No significant difference was observed between the 2 groups in the occurrence of hypertensive response to exercise (6.4% among seropositives and 5.9% among seronegatives), ST depression greater than 1 mm (0.8% and 2.0%), supraventricular premature beats (4.8% and 2.6%) or conduction defects (0.8% and 1.3%). Complex ventricular premature beats were recorded more often in seropositive subjects (12.8% and 3.9%; OR = 3.7, 95% CI = 1.4-9.8, P less than 0.01). The risk of an abnormal test increased with age in both groups. A history of cardiovascular symptoms, gender and body mass was not associated with the risk of an abnormal response in the test. The findings suggest that exercise testing might be a routine procedure when subjects with antibodies to T. cruzi are being assessed for participation in potentially high risk activities, such as heavy manual work.

Pulmonary rehabilitation improves cardiovascular response to exercise in COPD.

PubMed

Ramponi, Sara; Tzani, Panagiota; Aiello, Marina; Marangio, Emilio; Clini, Enrico; Chetta, Alfredo

2013-01-01

Pulmonary rehabilitation (PR) has emerged as a recommended standard of care in symptomatic COPD. We now studied whether PR may affect cardiovascular response to exercise in these patients. Twenty-seven patients (9 females aged 69 ± 8 years) with moderate-to-severe airflow obstruction admitted to a 9-week PR course performed a pre-to-post evaluation of lung function test and symptom-limited cardiopulmonary exercise test (CPET). Oxygen uptake (VO2), tidal volume (V(T)), dyspnea and leg fatigue scores were measured during CPET. Cardiovas-cular response was assessed by means of oxygen pulse (O2Pulse), the oxygen uptake efficiency slope and heart rate recovery at the 1st min. A significant increase in peak VO2 and in all cardiovascular parameters (p < 0.05) was found following PR when compared to baseline. Leg fatigue (p < 0.05), but not dyspnea, was significantly reduced after PR. When assessed at metabolic and ventilatory iso levels [% VCO2max and % minute ventilation (VEmax)], O2Pulse and V(T) were significantly higher (p < 0.05) at submaximal exercise (75 and 50% of VCO2max and VEmax) after PR when compared to baseline. V(T) percent changes at 75% VCO2max and 75% VEmax after PR significantly correlated with corresponding changes in O2Pulse (p < 0.01). In COPD patients, a PR training program improved the cardiovascular response during exercise at submaximal exercise independent of the external workload. This change was associated with an enhanced ventilatory function during exercise. Copyright © 2013 S. Karger AG, Basel.

Acute aerobic exercise differentially alters acylated ghrelin and perceived fullness in normal-weight and obese individuals.

PubMed

Heden, Timothy D; Liu, Ying; Park, Youngmin; Dellsperger, Kevin C; Kanaley, Jill A

2013-09-01

Adiposity alters acylated ghrelin concentrations, but it is unknown whether adiposity alters the effect of exercise and feeding on acylated ghrelin responses. Therefore, the purpose of this study was to determine whether adiposity [normal-weight (NW) vs. obese (Ob)] influences the effect of exercise and feeding on acylated ghrelin, hunger, and fullness. Fourteen NW and 14 Ob individuals completed two trials in a randomized counterbalanced fashion, including a prior exercise trial (EX) and a no exercise trial (NoEX). During the EX trial, the participants performed 1 h of treadmill walking (55-60% peak O2 uptake) during the evening, 12 h before a 4-h standardized mixed meal test. Frequent blood samples were taken and analyzed for acylated ghrelin, and a visual analog scale was used to assess perceived hunger and fullness. In NW individuals, EX, compared with NoEX, reduced fasting acylated ghrelin concentrations by 18% (P = 0.03), and, in response to feeding, the change in acylated ghrelin (P = 0.02) was attenuated by 39%, but perceived hunger and fullness were unaltered. In Ob individuals, despite no changes in fasting or postprandial acylated ghrelin concentrations with EX, postprandial fullness was attenuated by 46% compared with NoEX (P = 0.05). In summary, exercise performed the night before a meal suppresses acylated ghrelin concentrations in NW individuals without altering perceived hunger or fullness. In Ob individuals, despite no changes in acylated ghrelin concentrations, EX reduced the fullness response to the test meal. Acylated ghrelin and perceived fullness responses are differently altered by acute aerobic exercise in NW and Ob individuals.

The emerging role of exercise testing and stress echocardiography in valvular heart disease.

PubMed

Picano, Eugenio; Pibarot, Philippe; Lancellotti, Patrizio; Monin, Jean Luc; Bonow, Robert O

2009-12-08

Exercise testing has an established role in the evaluation of patients with valvular heart disease and can aid clinical decision making. Because symptoms may develop slowly and indolently in chronic valve diseases and are often not recognized by patients and their physicians, the symptomatic, blood pressure, and electrocardiographic responses to exercise can help identify patients who would benefit from early valve repair or replacement. In addition, stress echocardiography has emerged as an important component of stress testing in patients with valvular heart disease, with relevant established and potential applications. Stress echocardiography has the advantages of its wide availability, low cost, and versatility for the assessment of disease severity. The versatile applications of stress echocardiography can be tailored to the individual patient with aortic or mitral valve disease, both before and after valve replacement or repair. Hence, exercise-induced changes in valve hemodynamics, ventricular function, and pulmonary artery pressure, together with exercise capacity and symptomatic responses to exercise, provide the clinician with diagnostic and prognostic information that can contribute to subsequent clinical decisions. Nevertheless, there is a lack of convincing evidence that the results of stress echocardiography lead to clinical decisions that result in better outcomes, and therefore large-scale prospective randomized studies focusing on patient outcomes are needed in the future.

Effects of a 6-month exercise program pilot study on walking economy, peak physiological characteristics, and walking performance in patients with peripheral arterial disease.

PubMed

Crowther, Robert G; Leicht, Anthony S; Spinks, Warwick L; Sangla, Kunwarjit; Quigley, Frank; Golledge, Jonathan

2012-01-01

The purpose of this study was to examine the effects of a 6-month exercise program on submaximal walking economy in individuals with peripheral arterial disease and intermittent claudication (PAD-IC). Participants (n = 16) were randomly allocated to either a control PAD-IC group (CPAD-IC, n = 6) which received standard medical therapy, or a treatment PAD-IC group (TPAD-IC; n = 10) which took part in a supervised exercise program. During a graded treadmill test, physiological responses, including oxygen consumption, were assessed to calculate walking economy during submaximal and maximal walking performance. Differences between groups at baseline and post-intervention were analyzed via Kruskal-Wallis tests. At baseline, CPAD-IC and TPAD-IC groups demonstrated similar walking performance and physiological responses. Postintervention, TPAD-IC patients demonstrated significantly lower oxygen consumption during the graded exercise test, and greater maximal walking performance compared to CPAD-IC. These preliminary results indicate that 6 months of regular exercise improves both submaximal walking economy and maximal walking performance, without significant changes in maximal walking economy. Enhanced walking economy may contribute to physiological efficiency, which in turn may improve walking performance as demonstrated by PAD-IC patients following regular exercise programs.

Acute Physiological Responses to Short- and Long-Stage High-Intensity Interval Exercise in Cardiac Rehabilitation: A Pilot Study

PubMed Central

Tschakert, Gerhard; Kroepfl, Julia M.; Mueller, Alexander; Harpf, Hanns; Harpf, Leonhard; Traninger, Heimo; Wallner-Liebmann, Sandra; Stojakovic, Tatjana; Scharnagl, Hubert; Meinitzer, Andreas; Pichlhoefer, Patriz; Hofmann, Peter

2016-01-01

Despite described benefits of aerobic high-intensity interval exercise (HIIE), the acute responses during different HIIE modes and associated health risks have only been sparsely discovered in heart disease patients. Therefore, the aim of this study was to investigate the acute responses for physiological parameters, cardiovascular and inflammatory biomarkers, and catecholamines yielded by two different aerobic HIIE protocols compared to continuous exercise (CE) in phase III cardiac rehabilitation. Eight cardiac patients (7 with coronary heart disease, 1 with myocarditis; 7 males, 1 female; age: 63.0 ± 9.4 years; height: 1.74 ± 0.05 m; weight: 83.6 ± 8.7 kg), all but one treated with ß-blocking agents, performed a maximal symptom-limited incremental exercise test (IET) and three different exercise tests matched for mean load (Pmean) and total duration: 1) short HIIE with a peak workload duration (tpeak) of 20 s and a peak workload (Ppeak) equal to the maximum power output (Pmax) from IET; 2) long HIIE with a tpeak of 4 min, Ppeak was corresponding to the power output at 85 % of maximal heart rate (HRmax) from IET; 3) CE with a target workload equal to Pmean of both HIIE modes. Acute metabolic and peak cardiorespiratory responses were significantly higher during long HIIE compared to short HIIE and CE (p < 0.05) except HRpeak which tended to be higher in long HIIE than in short HIIE (p = 0.08). Between short HIIE and CE, no significant difference was found for any parameter. Acute responses of cardiovascular and inflammatory biomarkers and catecholamines didn’t show any significant difference between tests (p > 0.05). All health-related variables remained in a normal range in any test except NT-proBNP, which was already elevated at baseline. Despite a high Ppeak particularly in short HIIE, both HIIE modes were as safe and as well tolerated as moderate CE in cardiac patients by using our methodological approach. Key points High-intensity interval exercise (HIIE) with short peak workload durations (tpeak) induce a lower acute metabolic and peak cardiorespiratory response compared to intervals with long tpeak despite higher peak workload intensities and identical mean load. No significant difference for any physiological parameter was found between short HIIE and CE. Between short HIIE, long HIIE, and CE, no significant difference was found in the increase (or decrease, respectively,) of health related markers such as cardiovascular biomarkers, catecholamines, or inflammatory parameters during exercise. During all exercise modes, all risk markers remained in a normal range except for NT-proBNP which was, however, already elevated at baseline. Short HIIE, long HIIE, and CE were safely performed by patients with CHD or myocarditis in cardiac rehabilitation by using our methodological approach to exercise prescription. This approach included the prescription of exercise intensities with respect to LTP1, LTP2, and Pmax as well as a conscious setting of Pmean at a moderate level (80 % of PLTP2). Importantly, all exercise modes were matched for Pmean and exercise duration in order to enable a comparison of the three protocols. PMID:26957930

A Conceptual Framework to Measure Systems’ Performance during Emergency Preparedness Exercises

PubMed Central

Savoia, Elena; Agboola, Foluso; Biddinger, Paul D.

2014-01-01

Large-scale public health emergencies require a sophisticated, coordinated response involving multiple entities to protect health and minimize suffering. However, the rarity of such emergencies presents a barrier to gathering observational data about the effectiveness of the public health response before such events occur. For this reason, public health practitioners increasingly have relied on simulated emergencies, known as “exercises” as proxies to test their emergency capabilities. However, the formal evaluation of performance in these exercises, historically has been inconsistent, and there is little research to describe how data acquired from simulated emergencies actually support conclusions about the quality of the public health emergency response system. Over the past six years, we have designed and evaluated more than seventy public health emergency exercises, collaborating with public health agencies, hospitals and others to test a wide variety of systems and their capabilities. Using the data and experience that we gathered, we have developed a conceptual framework that describes the essential elements necessary to consider when applying performance measurement science to public health emergency exercises. We suggest that this framework may assist practitioners and researchers who wish to better measure performance in exercises and to improve public health emergency preparedness. PMID:25233015

Exercise training alters effect of high-fat feeding on the ACTH stress response in pigs.

PubMed

Jankord, Ryan; Ganjam, Venkataseshu K; Turk, James R; Hamilton, Marc T; Laughlin, M Harold

2008-06-01

Eating and physical activity behaviors influence neuroendocrine output. The purpose of this study was to test, in an animal model of diet-induced cardiovascular disease, the effects of high-fat feeding and exercise training on hypothalamo-pituitary-adrenocortical (HPA) axis activity. We hypothesized that a high-fat diet would increase circulating free fatty acids (FFAs) and decrease the adrenocorticotropic hormone (ACTH) and cortisol response to an acute stressor. We also hypothesized that exercise training would reverse the high-fat diet-induced changes in FFAs and thereby restore the ACTH and cortisol response. Pigs were placed in 1 of 4 groups (normal diet, sedentary; normal diet, exercise training; high-fat diet, sedentary; high-fat diet, exercise training; n = 8/group). Animals were placed on their respective dietary and activity treatments for 16-20 weeks. After completion of the treatments animals were anesthetized and underwent surgical intubation. Blood samples were collected after surgery and the ACTH and cortisol response to surgery was determined and the circulating concentrations of FFAs, glucose, cholesterol, insulin, and IGF-1 were measured. Consistent with our hypothesis, high-fat feeding increased FFAs by 200% and decreased the ACTH stress response by 40%. In exercise-trained animals, the high-fat diet also increased FFA; however, the increase in FFA in exercise-trained pigs was accompanied by a 60% increase in the ACTH response. The divergent effect of high-fat feeding on ACTH response was not expected, as exercise training alone had no effect on the ACTH response. Results demonstrate a significant interaction between diet and exercise and their effect on the ACTH response. The divergent effects of high-fat diet could not be explained by changes in weight gain, blood glucose, insulin, or IGF-1, as these were altered by high-fat feeding, but unaffected by exercise training. Thus, the increase in FFA with high-fat feeding may explain the blunted ACTH response to an acute stressor in sedentary animals, but cannot explain the exaggerated response in exercise trained animals.

Exercise training alters effect of high-fat feeding on the ACTH stress response in pigs

PubMed Central

Jankord, Ryan; Ganjam, Venkataseshu K.; Turk, James R.; Hamilton, Marc T.; Laughlin, M. Harold

2009-01-01

Eating and physical activity behaviors influence neuroendocrine output. The purpose of this study was to test, in an animal model of diet-induced cardiovascular disease, the effects of high-fat feeding and exercise training on hypothalamo–pituitary–adrenocortical (HPA) axis activity. We hypothesized that a high-fat diet would increase circulating free fatty acids (FFAs) and decrease the adrenocorticotropic hormone (ACTH) and cortisol response to an acute stressor. We also hypothesized that exercise training would reverse the high-fat diet-induced changes in FFAs and thereby restore the ACTH and cortisol response. Pigs were placed in 1 of 4 groups (normal diet, sedentary; normal diet, exercise training; high-fat diet, sedentary; high-fat diet, exercise training; n = 8/group). Animals were placed on their respective dietary and activity treatments for 16–20 weeks. After completion of the treatments animals were anesthetized and underwent surgical intubation. Blood samples were collected after surgery and the ACTH and cortisol response to surgery was determined and the circulating concentrations of FFAs, glucose, cholesterol, insulin, and IGF-1 were measured. Consistent with our hypothesis, high-fat feeding increased FFAs by 200% and decreased the ACTH stress response by 40%. In exercise-trained animals, the high-fat diet also increased FFA; however, the increase in FFA in exercise-trained pigs was accompanied by a 60% increase in the ACTH response. The divergent effect of high-fat feeding on ACTH response was not expected, as exercise training alone had no effect on the ACTH response. Results demonstrate a significant interaction between diet and exercise and their effect on the ACTH response. The divergent effects of high-fat diet could not be explained by changes in weight gain, blood glucose, insulin, or IGF-1, as these were altered by high-fat feeding, but unaffected by exercise training. Thus, the increase in FFA with high-fat feeding may explain the blunted ACTH response to an acute stressor in sedentary animals, but cannot explain the exaggerated response in exercise trained animals. PMID:18461098

Dynamic exercise training prevents exercise pressor reflex overactivity in spontaneously hypertensive rats

PubMed Central

Iwamoto, Gary A.; Vongpatanasin, Wanpen; Mitchell, Jere H.; Smith, Scott A.

2015-01-01

Cardiovascular responses to exercise are exaggerated in hypertension. We previously demonstrated that this heightened cardiovascular response to exercise is mediated by an abnormal skeletal muscle exercise pressor reflex (EPR) with important contributions from its mechanically and chemically sensitive components. Exercise training attenuates exercise pressor reflex function in healthy subjects as well as in heart failure rats. However, whether exercise training has similar physiological benefits in hypertension remains to be elucidated. Thus we tested the hypothesis that the EPR overactivity manifest in hypertension is mitigated by exercise training. Changes in mean arterial pressure (MAP) and renal sympathetic nerve activity (RSNA) in response to muscle contraction, passive muscle stretch, and hindlimb intra-arterial capsaicin administration were examined in untrained normotensive Wistar-Kyoto rats (WKYUT; n = 6), exercise-trained WKY (WKYET; n = 7), untrained spontaneously hypertensive rats (SHRUT; n = 8), and exercise-trained SHR (SHRET; n = 7). Baseline MAP after decerebration was significantly decreased by 3 mo of wheel running in SHRET (104 ± 9 mmHg) compared with SHRUT (125 ± 10 mmHg). As previously reported, the pressor and renal sympathetic responses to muscle contraction, stretch, and capsaicin administration were significantly higher in SHRUT than WKYUT. Exercise training significantly attenuated the enhanced contraction-induced elevations in MAP (SHRUT: 53 ± 11 mmHg; SHRET: 19 ± 3 mmHg) and RSNA (SHRUT: 145 ± 32%; SHRET: 57 ± 11%). Training produced similar attenuating effects in SHR during passive stretch and capsaicin administration. These data demonstrate that the abnormally exaggerated EPR function that develops in hypertensive rats is significantly diminished by exercise training. PMID:26163445

Evaluation of Exercise Response in a Young, High Risk Population: Submaximal Invasive Cardiopulmonary Exercise Testing (ICPET) in Active Duty Soldiers

DTIC Science & Technology

2017-03-17

Submaximal Invasive Cardiopulmonary Exercise Testing iCPET in AD Soldiers presented at/published to American College of Cardiology’s 661h Annual...disclaimer statement for research involving animals . as required by AFMAN 40-401 IP : " The experiments reported herein were conducted according to the...principles set forth in the National Institute of Health Publication No. 80-23, Guide for the Care and Use of Laboratory Animals and the Animal

Effects of Multicomponent Exercise on Functional and Cognitive Parameters of Hypertensive Patients: A Quasi-Experimental Study

PubMed Central

Feriani, Daniele Jardim; Gonçalves, Ivan de Oliveira; Asano, Ricardo Yukio; Aguiar, Samuel da Silva; Uchida, Marco Carlos

2017-01-01

Purpose. The present study aimed to investigate the impact of a 6-month multicomponent exercise program (MCEP) on physical function and cognitive parameters of normotensive (NTS) and hypertensive (HTS) older patients and verify if age can influence the adaptations in response to the exercise. Methods. A total of 218 subjects, 101 NTS and 117 HTS, were recruited and underwent functional and cognitive evaluations before and after six months of a MCEP. The program of exercise was performed twice a week, for 26 weeks. The physical exercises were thought to mimic the activities of daily living and, therefore, aggregated functional and walking exercises. Exercise sessions were performed at moderate intensity. Results. Data indicated that HTS and NST patients showed a similar increase in the performance of walking speed test and one-leg stand test after the MCEP. Regarding age, results did not show differences in the magnitude of adaptations between old and young HTS and NTS patients. Conclusions. Data of the present study indicated that a 6-month MCEP was able to increase equally balance and mobility in NTS and HTS patients. Moreover, data demonstrated that aging did not seem to impair the capacity to adapt in response to exercise in both groups. PMID:28409030

Testing of neuroendocrine function in astronauts as related to fluid shifts

NASA Astrophysics Data System (ADS)

Sauseng-Fellegger, G.; König, E. M.; Hinghofer-Szalkay, H.; Jezová, D.; Vigas, M.

We addressed the question of optimal conditions for neuroendocrine and cardiovascular testing in astronauts. We tested stress reactions during LBNP of ≤-50 mm Hg. There was a mild transient elevation of plasma GH concentration and a nonsignificant rise of plasma ACTH, while PRL, insulin and glucose remained unchanged. Aldosterone was decreased 5 and 10 min after beginning of LBNP, thereafter rose significantly, and displayed a further significant concentration increase 5 min post-LBNP. The endocrine and cardiovascular responses to submaximal exercise were tested at 8.00 am and 8.00 pm. Exercise-induced changes of heart rate and blood pressure remained unchanged with daytime whereas plasma concentrations of epinephrine, GH and PRL in response to work load were significantly higher in the evening than in the morning. As expected, basal resting values of plasma cortisol were significantly lower in the evening than in the morning but were similar one hour after cessation of exercise. Our findings demonstrate the importance of frequent sampling in case of transient physiological phenomena, and contribute to existing knowledge on circadian influences upon neuroendocrine stress responses.

Locomotor Muscle Fatigue Does Not Alter Oxygen Uptake Kinetics during High-Intensity Exercise.

PubMed

Hopker, James G; Caporaso, Giuseppe; Azzalin, Andrea; Carpenter, Roger; Marcora, Samuele M

2016-01-01

The [Formula: see text] slow component ([Formula: see text]) that develops during high-intensity aerobic exercise is thought to be strongly associated with locomotor muscle fatigue. We sought to experimentally test this hypothesis by pre-fatiguing the locomotor muscles used during subsequent high-intensity cycling exercise. Over two separate visits, eight healthy male participants were asked to either perform a non-metabolically stressful 100 intermittent drop-jumps protocol (pre-fatigue condition) or rest for 33 min (control condition) according to a random and counterbalanced order. Locomotor muscle fatigue was quantified with 6-s maximal sprints at a fixed pedaling cadence of 90 rev·min -1 . Oxygen kinetics and other responses (heart rate, capillary blood lactate concentration and rating of perceived exertion, RPE) were measured during two subsequent bouts of 6 min cycling exercise at 50% of the delta between the lactate threshold and [Formula: see text] determined during a preliminary incremental exercise test. All tests were performed on the same cycle ergometer. Despite significant locomotor muscle fatigue ( P = 0.03), the [Formula: see text] was not significantly different between the pre-fatigue (464 ± 301 mL·min -1 ) and the control (556 ± 223 mL·min -1 ) condition ( P = 0.50). Blood lactate response was not significantly different between conditions ( P = 0.48) but RPE was significantly higher following the pre-fatiguing exercise protocol compared with the control condition ( P < 0.01) suggesting higher muscle recruitment. These results demonstrate experimentally that locomotor muscle fatigue does not significantly alter the [Formula: see text] kinetic response to high intensity aerobic exercise, and challenge the hypothesis that the [Formula: see text] is strongly associated with locomotor muscle fatigue.

Patients with a hypertensive response to exercise have impaired left ventricular diastolic function.

PubMed

Takamura, Takeshi; Onishi, Katsuya; Sugimoto, Tadafumi; Kurita, Tairo; Fujimoto, Naoki; Dohi, Kaoru; Tanigawa, Takashi; Isaka, Naoki; Nobori, Tsutomu; Ito, Masaaki

2008-02-01

An exaggerated increase in systolic blood pressure prolongs myocardial relaxation and increases left ventricular (LV) chamber stiffness, resulting in an increase in LV filling pressure. We hypothesize that patients with a marked hypertensive response to exercise (HRE) have LV diastolic dysfunction leading to exercise intolerance, even in the absence of resting hypertension. We recruited 129 subjects (age 63+/-9 years, 64% male) with a preserved ejection fraction and a negative stress test. HRE was evaluated at the end of a 6-min exercise test using the modified Bruce protocol. Patients were categorized into three groups: a group without HRE and without resting hypertension (control group; n=30), a group with HRE but without resting hypertension (HRE group; n=25), and a group with both HRE and resting hypertension (HTN group; n=74). Conventional Doppler and tissue Doppler imaging were performed at rest. After 6-min exercise tests, systolic blood pressure increased in the HRE and HTN groups, compared with the control group (226+/-17 mmHg, 226+/-17 mmHg, and 180+/-15 mmHg, respectively, p<0.001). There were no significant differences in LV ejection fraction, LV end-diastolic diameter, and early mitral inflow velocity among the three groups. However, early diastolic mitral annular velocity (E') was significantly lower and the ratio of early diastolic mitral inflow velocity (E) to E' (E/E') was significantly higher in patients of the HRE and HTN groups compared to controls (E': 5.9+/-1.6 cm/s, 5.9+/-1.7 cm/s, 8.0+/-1.9 cm/s, respectively, p<0.05). In conclusion, irrespective of the presence of resting hypertension, patients with hypertensive response to exercise had impaired LV longitudinal diastolic function and exercise intolerance.

Locomotor Muscle Fatigue Does Not Alter Oxygen Uptake Kinetics during High-Intensity Exercise

PubMed Central

Hopker, James G.; Caporaso, Giuseppe; Azzalin, Andrea; Carpenter, Roger; Marcora, Samuele M.

2016-01-01

The V˙O2 slow component (V˙O2sc) that develops during high-intensity aerobic exercise is thought to be strongly associated with locomotor muscle fatigue. We sought to experimentally test this hypothesis by pre-fatiguing the locomotor muscles used during subsequent high-intensity cycling exercise. Over two separate visits, eight healthy male participants were asked to either perform a non-metabolically stressful 100 intermittent drop-jumps protocol (pre-fatigue condition) or rest for 33 min (control condition) according to a random and counterbalanced order. Locomotor muscle fatigue was quantified with 6-s maximal sprints at a fixed pedaling cadence of 90 rev·min−1. Oxygen kinetics and other responses (heart rate, capillary blood lactate concentration and rating of perceived exertion, RPE) were measured during two subsequent bouts of 6 min cycling exercise at 50% of the delta between the lactate threshold and V˙O2max determined during a preliminary incremental exercise test. All tests were performed on the same cycle ergometer. Despite significant locomotor muscle fatigue (P = 0.03), the V˙O2sc was not significantly different between the pre-fatigue (464 ± 301 mL·min−1) and the control (556 ± 223 mL·min−1) condition (P = 0.50). Blood lactate response was not significantly different between conditions (P = 0.48) but RPE was significantly higher following the pre-fatiguing exercise protocol compared with the control condition (P < 0.01) suggesting higher muscle recruitment. These results demonstrate experimentally that locomotor muscle fatigue does not significantly alter the V˙O2 kinetic response to high intensity aerobic exercise, and challenge the hypothesis that the V˙O2sc is strongly associated with locomotor muscle fatigue. PMID:27790156

Impaired pituitary hormonal response to exhaustive exercise in overtrained endurance athletes.

PubMed

Urhausen, A; Gabriel, H H; Kindermann, W

1998-03-01

The aim of the present prospective longitudinal study was to investigate the hormonal response in overtrained athletes at rest and during exercise consisting of a short-term exhaustive endurance test on a cycle ergometer at an intensity 10% above the individual anaerobic threshold. Over a period of 19+/-1 months, 17 male endurance athletes (cyclists and triathletes; age 23.4+/-1.6 yr; VO2max. 61.2+/-1.8 mL x min(-1) x kg(-1); means+/-SEM) were examined five times on two separate days under standardized conditions. Short-term overtraining states (OT, N=15) were primarily induced by an increase of frequency of high-intensive bouts of exercise or competitions without increase of the total amount of training. OT was compared with normal training states intraindividually (NS, N=62). During OT, the time to exhaustion of the exercise test was significantly decreased by 27% on average. At rest and during exercise, the concentrations in plasma and the nocturnal excretion in urine of free epinephrine and norepinephrine were not significantly changed during OT. At physical rest, the concentrations of (free) testosterone, cortisol, luteinizing hormone, follicle-stimulating hormone, adrenocorticotropic hormone, growth hormone, and insulin during OT were comparable with those during NS. A significantly (P < 0.025) lower maximal exercise-induced increase of the adrenocorticotropic hormone and growth hormone, as well as a trend for a decrease of cortisol (P=0.060) and insulin (P=0.036), was measured. The response of free catecholamines as well as the ergometric performance of an all-out 30-s test was unchanged. Serum urea, uric acid, ferritin, and activity of creatine kinase showed no differences between conditions. In conclusion, the results confirm the hypothesis of a hypothalamo-pituitary dysregulation during OT expressed by an impaired response of pituitary hormones to exhaustive short-endurance exercise.

Exaggerated blood pressure response to exercise in athletes: dysmetabolism or altered autonomic nervous system modulation?

PubMed

Turmel, Julie; Bougault, Valérie; Boulet, Louis-Philippe; Poirier, Paul

2012-10-01

The importance of exercise-induced exaggerated blood pressure (BP) response in endurance athletes is not known. To assess the hemodynamic parameters and metabolic profile in athletes with an exaggerated BP response to exercise. Forty-four endurance athletes underwent a maximal exercise test, a 24-h ambulatory blood pressure monitoring, a 24-h Holter assessment, and sampling of blood on two occasions: (a) during intense training and (b) following 3 weeks without training. During the training period, 11 athletes showed an exaggerated BP response to exercise, whereas seven of these 11 athletes also showed an exaggerated BP response during the resting period. Elevation in systolic BP was greater in athletes with an exaggerated BP response than athletes with a normal BP response to exercise (resting: 84 ± 22 vs. 60 ± 18 mmHg, P = 0.02; training: 100 ± 21 vs. 70 ± 18 mmHg, P = 0.004). During the training period, athletes with an exaggerated BP response to exercise showed higher systolic BP values on 24-h ambulatory blood pressure monitoring (136 ± 15 vs. 118 ± 8 mmHg, P = 0.02). During the resting period, athletes with an exaggerated BP response to exercise had lower apolipoprotein-A1 (1.3 ± 0.1 vs. 1.5 ± 0.2 g/l, P = 0.009), and higher SDNN (259 ± 47 vs. 209 ± 52 ms, P = 0.03) and pNN50 (0.4 ± 0.1 vs. 0.3 ± 0.1%, P = 0.05). These observations may represent the first sign of a slight metabolic disturbance associated with vascular wall abnormalities, although the parameters remain within normal values.

Exaggerated blood pressure response to exercise and late-onset hypertension in young adults.

PubMed

Yzaguirre, Ignasi; Grazioli, Gonzalo; Domenech, Mónica; Vinuesa, Antonio; Pi, Ramon; Gutierrez, Josep; Coca, Antonio; Brugada, Josep; Sitges, Marta

2017-12-01

Exaggerated blood pressure response (EBPR) during exercise has been associated with an increased risk of incidental systemic hypertension and cardiovascular morbidity; however, there is no consensus definition of EBPR. We aimed to determine which marker best defines EBPR during exercise and to predict the long-term development of hypertension in individuals younger than 50 years. We reviewed 107 exercise tests performed in 1992, applied several reported methods to define EBPR at moderate and maximum exercise, and contacted the patients by telephone 20 years after the test to verify hypertension status. Finally, we determined which definition best predicted incidental hypertension at 20-year follow-up. The mean age of the participants at the time of exercise testing was 25.7±11.1 years. Logistic regression showed a significant association of diastolic blood pressure of more than 95 mmHg at peak exercise and systolic pressure more than 180 mmHg at moderate exercise with new-onset hypertension at 20-year follow-up [odds ratio: 6.3 (2.09-18.9) and odds ratio: 7.09 (2.31-21.7), respectively]. If EBPR was present, as defined by at least one of these parameters, the probability of incidental later onset hypertension was 70%. In our population, diastolic blood pressure of more than 95 mmHg at maximum exercise or systolic blood pressure more than 180 mmHg at moderate-intensity exercise (100 W) were the best predictors of new-onset hypertension at long-term follow-up. Individuals with EBPR according to these criteria should be monitored closely to detect the early development of hypertension.

Stress responses during aerobic exercise in relation to motivational dominance and state.

PubMed

Thatcher, Joanne; Kuroda, Yusuke; Legrand, Fabien D; Thatcher, Rhys

2011-02-01

We examined the hypothesis that congruence between motivational dominance and state results in optimal psychological responses and performance during exercise. Twenty participants (10 telic dominant and 10 paratelic dominant) rated their stress at 5 min intervals as they cycled on an ergometer at gas exchange threshold for 30 min in both telic and paratelic state manipulated conditions. Participants then performed a test to exhaustion at a resistance equivalent to 110% of VO(2max). The hypothesized interaction between condition and dominance was significant for internal tension stress, as paratelic dominants were more stressed than telic dominants when exercising in the telic state and telic dominants were more stressed than paratelic dominants when exercising in the paratelic state. Similarly, the condition × dominance interaction for internal stress discrepancy was significant, as paratelic dominants reported greater internal stress discrepancy exercising in the telic compared with the paratelic state. Findings are discussed in relation to the application of reversal theory for understanding stress responses during aerobic exercise.

Exercise performance, core temperature, and metabolism after prolonged restricted activity and retraining in dogs

NASA Technical Reports Server (NTRS)

Nazar, K.; Greenleaf, J. E.; Pohoska, E.; Turlejska, E.; Kaciuba-Uscilko, H.; Kozlowski, S.

1992-01-01

Physiological effects of restricted activity (RA) and subsequent retraining have been studied. Ten male mongrel dogs performed a submaximal exercise endurance test on a treadmill during kennel control, after 8 weeks of cage confinement and after eight weeks of retraining using the same treadmill protocol 1 h/d for 6 d/week. Data obtained show that RA reduces exercise endurance, the effectiveness of exercise thermoregulation, muscle glycogen stores, and the lipolytic response to exercise and to noradrenaline stimulation.

Time course of vasodilatory responses in skeletal muscle arterioles: role in hyperemia at onset of exercise

NASA Technical Reports Server (NTRS)

Wunsch, S. A.; Muller-Delp, J.; Delp, M. D.

2000-01-01

At the onset of dynamic exercise, muscle blood flow increases within 1-2 s. It has been postulated that local vasodilatory agents produced by the vascular endothelium or the muscle itself contribute to this response. We hypothesized that only vasodilators that act directly on the vascular smooth muscle could produce vasodilation of skeletal muscle arterioles in <2 s. To test this hypothesis, we determined the time course of the vasodilatory response of isolated skeletal muscle arterioles to direct application of potassium chloride, adenosine, acetylcholine, and sodium nitroprusside. Soleus and gastrocnemius muscles were dissected from the hindlimbs of male Sprague-Dawley rats. First-order arterioles (100-200 microm) were isolated, cannulated on micropipettes, and pressurized to 60 cmH(2)O in an organ bath. Vasodilatory agents were added directly to the bath, and diameter responses of the arterioles were recorded in real time on a videotape recorder. Frame-by-frame analysis of the diameter responses indicated that none of the vasodilator agents tested produced significant diameter increases in <4 s in either soleus or gastrocnemius muscle arterioles. These results indicate that, although these local vasodilators produce significant vasodilation of skeletal muscle resistance arterioles, these responses are not rapid enough (within 1-2 s) to contribute to the initiation of the exercise hyperemic response at the onset of dynamic exercise.

Effects of 14 days of head-down tilt bed rest on cutaneous vasoconstrictor responses in humans

NASA Technical Reports Server (NTRS)

Wilson, Thad E.; Shibasaki, Manabu; Cui, Jian; Levine, Benjamin D.; Crandall, Craig G.

2003-01-01

This study tested the hypothesis that head-down tilt bed rest (HDBR) reduces adrenergic and nonadrenergic cutaneous vasoconstrictor responsiveness. Additionally, an exercise countermeasure group was included to identify whether exercise during bed rest might counteract any vasoconstrictor deficits that arose during HDBR. Twenty-two subjects underwent 14 days of strict 6 degrees HDBR. Eight of these 22 subjects did not exercise during HDBR, while 14 of these subjects exercised on a supine cycle ergometer for 90 min a day at 75% of pre-bed rest heart rate maximum. To assess alpha-adrenergic vasoconstrictor responsiveness, intradermal microdialysis was used to locally administer norepinephrine (NE), while forearm skin blood flow (SkBF; laser-Doppler flowmetry) was monitored over microdialysis membranes. Nonlinear regression modeling was used to identify the effective drug concentration that caused 50% of the cutaneous vasoconstrictor response (EC(50)) and minimum values from the SkBF-NE dose-response curves. In addition, the effects of HDBR on nonadrenergic cutaneous vasoconstriction were assessed via the venoarteriolar response of the forearm and leg. HDBR did not alter EC(50) or the magnitude of cutaneous vasoconstriction to exogenous NE administration regardless of whether the subjects exercised during HDBR. Moreover, HDBR did not alter the forearm venoarteriolar response in either the control or exercise groups during HDBR. However, HDBR significantly reduced the magnitude of cutaneous vasoconstriction due to the venoarteriolar response in the leg, and this response was similarly reduced in the exercise group. These data suggest that HDBR does not alter cutaneous vasoconstrictor responses to exogenous NE administration, whereas cutaneous vasoconstriction of the leg due to the venoarteriolar response is reduced after HDBR. It remains unclear whether attenuated venoarteriolar responses in the lower limbs contribute to reduced orthostatic tolerance after bed rest and spaceflight.

Impact of sympathetic nervous system activity on post-exercise flow-mediated dilatation in humans.

PubMed

Atkinson, Ceri L; Lewis, Nia C S; Carter, Howard H; Thijssen, Dick H J; Ainslie, Philip N; Green, Daniel J

2015-12-01

Transient reduction in vascular function following systemic large muscle group exercise has previously been reported in humans. The mechanisms responsible are currently unknown. We hypothesised that sympathetic nervous system activation, induced by cycle ergometer exercise, would contribute to post-exercise reductions in flow-mediated dilatation (FMD). Ten healthy male subjects (28 ± 5 years) undertook two 30 min sessions of cycle exercise at 75% HR(max). Prior to exercise, individuals ingested either a placebo or an α1-adrenoreceptor blocker (prazosin; 0.05 mg kg(-1)). Central haemodynamics, brachial artery shear rate (SR) and blood flow profiles were assessed throughout each exercise bout and in response to brachial artery FMD, measured prior to, immediately after and 60 min after exercise. Cycle exercise increased both mean and antegrade SR (P < 0.001) with retrograde SR also elevated under both conditions (P < 0.001). Pre-exercise FMD was similar on both occasions, and was significantly reduced (27%) immediately following exercise in the placebo condition (t-test, P = 0.03). In contrast, FMD increased (37%) immediately following exercise in the prazosin condition (t-test, P = 0.004, interaction effect P = 0.01). Post-exercise FMD remained different between conditions after correction for baseline diameters preceding cuff deflation and also post-deflation SR. No differences in FMD or other variables were evident 60 min following recovery. Our results indicate that sympathetic vasoconstriction competes with endothelium-dependent dilator activity to determine post-exercise arterial function. These findings have implications for understanding the chronic impacts of interventions, such as exercise training, which affect both sympathetic activity and arterial shear stress. © 2015 The Authors. The Journal of Physiology © 2015 The Physiological Society.

Contribution of autonomic dysfunction to abnormal exercise blood pressure in type 2 diabetes mellitus.

PubMed

Weston, Kassia S; Sacre, Julian W; Jellis, Christine L; Coombes, Jeff S

2013-01-01

The purpose of this study was to compare the presence and severity of autonomic dysfunction in type 2 diabetes mellitus patients, with and without exaggerated blood pressure responses to exercise. We performed a cross-sectional analysis of 98 patients with type 2 diabetes mellitus (aged 59±9). Both time (standard deviation of RR intervals, root-mean-square of successive RR interval differences) and frequency (total spectral power, high frequency, low frequency, very low frequency) domains of heart rate variability were analysed in a 5 min recording at rest and 20 min after a maximal treadmill test. An exaggerated blood pressure response to exercise was identified by peak blood pressure ≥190/105 mmHg (women) or ≥210/105 mmHg (men). Each group of either exaggerated exercise blood pressure response or normal blood pressure response consisted of 49 patients. At rest there were no significant differences between groups for all time and frequency domain parameters of heart rate variability. Post-exercise, there was a significant (p<0.05) reduction in the SDNN, RMSSD and TP in the exaggerated exercise blood pressure group. Independent correlates (p<0.01) of exercise systolic blood pressure included post-exercise TP, resting systolic blood pressure, cardiac autonomic neuropathy and beta-blockers (beta=-0.28, adj. R² = 0.32, p<0.001). Reduced post-exercise heart rate variability in patients with type 2 diabetes mellitus, with an exaggerated exercise blood pressure response suggests preclinical autonomic dysfunction characterized by impaired vagal modulation. Copyright © 2012 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Genetic polymorphisms of beta1 adrenergic receptor and their influence on the cardiovascular responses to metoprolol in a South Indian population.

PubMed

Mahesh Kumar, Koratagere Nagaraju; Ramu, Periasamy; Rajan, Subramanian; Shewade, Deepak Gopal; Balachander, Jayaraman; Adithan, Chandrasekaran

2008-11-01

Beta-blockers show interindividual and interethnic variability in their response. Such variability might be due to the polymorphic variations in the beta1 adrenergic receptor genes viz, Ser49Gly and Arg389Gly. The study evaluated the influence of Ser49Gly and Arg389Gly polymorphisms on the cardiovascular responses to metoprolol in a South Indian population. Forty-one genetically prescreened healthy male volunteers participated in the study. They were divided on the basis of genotype of each polymorphism: Ser49Ser, Ser49Gly, and Gly49Gly and Arg389Arg, Arg389Gly, and Gly389Gly. They were also grouped into combination genotypes viz, S49S R389R, S49G R389R, G49G R389R, S49S R389G, S49S G389G, and S49G R389G. They were subjected to treadmill exercise testing, and cardiovascular parameters were measured before and after metoprolol administration. Metoprolol concentration was determined by reversed phase high-performance liquid chromatography method. The diastolic blood pressure (DBP) was significantly lower in S49S/G389G group when compared to S49S/A389A group. The cardiac parameters were significantly increased in all the genotype groups during treadmill exercise test done for a period of 9 minutes. During predrug treadmill exercise at the end of third and sixth minute, Gly49Gly showed a higher increase in heart rate and volume of oxygen consumption compared to Ser49Ser. Same group showed a higher increase of volume of oxygen consumption at the end of ninth minute of exercise compared to the Ser49Ser. Systolic and diastolic blood pressures were not different between Ser49Gly polymorphisms. However, there was no statistical difference between the genotype groups of both polymorphisms at any stage of post-drug treadmill exercise. The analysis of combination of genotypes showed no significant difference during predrug and postdrug exercise testing. The increase in cardiac responses to treadmill test was influenced by Ser49Gly polymorphism. Nevertheless, the above polymorphisms did not alter the beta-blocker response during treadmill exercise in South Indian population.

Effects of Three-Day Bed Rest on Physiological Responses to Graded Exercise in Endurance Athletes, Body Builders and Sedentary Men

NASA Technical Reports Server (NTRS)

Smorawinski, J.; Nazar, K.; Kaciuza-Uscilko; Kaminska, E.; Kodrzycka, A.; Bicz, B.; Greenleaf, J. E.

2001-01-01

To test the hypotheses that short-term bed rest (BR) deconditioning influences metabolic, cardiorespiratory and neurohormonal responses to exercise and that these effects depend on the subjects' training status, 12 sedentary men, and 10 endurance- and 10 strength-trained athletes were submitted to three-day BR. Before and after BR they performed incremental exercise tests until volitional exhaustion. Respiratory gas exchange and HR were recorded continuously and stroke volume (SV) was measured at submaximal loads. Blood was taken for lactate [LA], adrenaline [A], noradrenaline [NA], renin activity (PRA), growth hormone [hGH], testosterone and cortisol determination. Reduction of peak oxygen uptake (V02peak) after BR was greater in the endurance athletes than in the remaining groups (17 % vs. 10%). Decrements in VO2peak correlated positively with the initial values (r = 0.73, p is less than 0.001). Resting and exercise respiratory exchange ratios were increased in athletes. Cardiac output was unchanged by BR in all groups, but exercise HR was increased and SV diminished in the sedentary subjects. The submaximal [LA] and [LA] thresholds were decreased the in endurance athletes from 71 to 60% V02 peak (p is less than0.001), they also had an earlier increase in [NA], an attenuated increase in [hGH], and accentuated PRA and cortisol elevations during exercise. These effects were insignificant in the remaining subjects. In conclusion: reduction of exercise performance and modifications in neurohormonal response to exercise after BR depend on the previous level and mode of physical training, being the most pronounced in the endurance athletes.

Effects of Three-Day Bed Rest on Physiological Responses to Graded Exercise in Endurance Athletes, Body Builders and Sedentary Men

NASA Technical Reports Server (NTRS)

Smorawinski, J.; Nazar, K.; Kaciuza-Uscilko, H.; Kaminska, E.; Cybulski, G.; Kodrzycka, A.; Bice, B.; Greenleaf, J. E.; Sun, Sid (Technical Monitor)

2001-01-01

To test the hypotheses that short-term bed rest (BR) deconditioning influences metabolic, cardiorespiratory and neurohormonal responses to exercise and that these effects depend on the subjects' training status 12 sedentary men, and 10 endurance- and 10 strength-trained athletes were submitted to three-day BR. Before and after BR they performed incremental exercise test until volitional exhaustion. Respiratory gas exchange and HR were recorded continuously and stroke volume (SV) was measured at submaximal loads. Blood was taken for lactate [LA], adrenaline [A], noradrenaline, [NA], renting activity (PRA), growth hormone [hGH], testosterone and cortisol determination. Reduction of peak oxygen uptake (VO2peak) after BR was greater in the endurance athletes (than in the remaining groups (17 % vs. 100%). Decrements in VO2peak correlated positively with the initial values (r = 0.73, p less than 0.001). Resting and exercise respiratory exchange ratios were increased in athletes. Cardiac output was unchanged by BR in all groups, but exercise HR was increased and SV diminished in the sedentary subjects. The submaximal [LA] and [LA] thresholds were decreased the in endurance athletes from 71 to 60 %VO2 peak (p less than 0.001); they also had an earlier increase in [NA], and an attenuated increase in [hGH), and accentuated PRA and cortisol elevations during exercise. These effects were insignificant in the remaining subjects. In conclusion: reduction of exercise performance and modifications in neurohormonal response to exercise after BR depend on the previous level and mode of physical training, being the most pronounced in the endurance athletes.

Effects of 3-day bed rest on physiological responses to graded exercise in athletes and sedentary men

NASA Technical Reports Server (NTRS)

Smorawinski, J.; Nazar, K.; Kaciuba-Uscilko, H.; Kaminska, E.; Cybulski, G.; Kodrzycka, A.; Bicz, B.; Greenleaf, J. E.

2001-01-01

To test the hypotheses that short-term bed-rest (BR) deconditioning influences metabolic, cardiorespiratory, and neurohormonal responses to exercise and that these effects depend on the subjects' training status, 12 sedentary men and 10 endurance- and 10 strength-trained athletes were submitted to 3-day BR. Before and after BR they performed incremental exercise test until volitional exhaustion. Respiratory gas exchange and heart rate (HR) were recorded continuously, and stroke volume (SV) was measured at submaximal loads. Blood was taken for lactate concentration ([LA]), epinephrine concentration ([Epi]), norepinephrine concentration ([NE]), plasma renin activity (PRA), human growth hormone concentration ([hGH]), testosterone, and cortisol determination. Reduction of peak oxygen uptake (VO(2 peak)) after BR was greater in the endurance athletes than in the remaining groups (17 vs. 10%). Decrements in VO(2 peak) correlated positively with the initial values (r = 0.73, P < 0.001). Resting and exercise respiratory exchange ratios were increased in athletes. Cardiac output was unchanged by BR in all groups, but exercise HR was increased and SV diminished in the sedentary subjects. The submaximal [LA] and [LA] thresholds were decreased in the endurance athletes from 71 to 60% VO(2 peak) (P < 0.001); they also had an earlier increase in [NE], an attenuated increase in [hGH], and accentuated PRA and cortisol elevations during exercise. These effects were insignificant in the remaining subjects. In conclusion, reduction of exercise performance and modifications in neurohormonal response to exercise after BR depend on the previous level and mode of physical training, being the most pronounced in the endurance athletes.

Effects of 3-day bed rest on physiological responses to graded exercise in athletes and sedentary men.

PubMed

Smorawiński, J; Nazar, K; Kaciuba-Uscilko, H; Kamińska, E; Cybulski, G; Kodrzycka, A; Bicz, B; Greenleaf, J E

2001-07-01

To test the hypotheses that short-term bed-rest (BR) deconditioning influences metabolic, cardiorespiratory, and neurohormonal responses to exercise and that these effects depend on the subjects' training status, 12 sedentary men and 10 endurance- and 10 strength-trained athletes were submitted to 3-day BR. Before and after BR they performed incremental exercise test until volitional exhaustion. Respiratory gas exchange and heart rate (HR) were recorded continuously, and stroke volume (SV) was measured at submaximal loads. Blood was taken for lactate concentration ([LA]), epinephrine concentration ([Epi]), norepinephrine concentration ([NE]), plasma renin activity (PRA), human growth hormone concentration ([hGH]), testosterone, and cortisol determination. Reduction of peak oxygen uptake (VO(2 peak)) after BR was greater in the endurance athletes than in the remaining groups (17 vs. 10%). Decrements in VO(2 peak) correlated positively with the initial values (r = 0.73, P < 0.001). Resting and exercise respiratory exchange ratios were increased in athletes. Cardiac output was unchanged by BR in all groups, but exercise HR was increased and SV diminished in the sedentary subjects. The submaximal [LA] and [LA] thresholds were decreased in the endurance athletes from 71 to 60% VO(2 peak) (P < 0.001); they also had an earlier increase in [NE], an attenuated increase in [hGH], and accentuated PRA and cortisol elevations during exercise. These effects were insignificant in the remaining subjects. In conclusion, reduction of exercise performance and modifications in neurohormonal response to exercise after BR depend on the previous level and mode of physical training, being the most pronounced in the endurance athletes.

Hemodynamic exercise testing. A valuable tool in the selection of cardiac transplantation candidates.

PubMed

Chomsky, D B; Lang, C C; Rayos, G H; Shyr, Y; Yeoh, T K; Pierson, R N; Davis, S F; Wilson, J R

1996-12-15

Peak exercise oxygen consumption (Vo2), a noninvasive index of peak exercise cardiac output (CO), is widely used to select candidates for heart transplantation. However, peak exercise Vo2 can be influenced by noncardiac factors such as deconditioning, motivation, or body composition and may yield misleading prognostic information. Direct measurement of the CO response to exercise may avoid this problem and more accurately predict prognosis. Hemodynamic and ventilatory responses to maximal treadmill exercise were measured in 185 ambulatory patients with chronic heart failure who had been referred for cardiac transplantation (mean left ventricular ejection fraction, 22 +/- 7%; mean peak Vo2, 12.9 +/- 3.0 mL. min-1.kg-1). CO response to exercise was normal in 83 patients and reduced in 102. By univariate analysis, patients with normal CO responses had a better 1-year survival rate (95%) than did those with reduced CO responses (72%) (P < .0001). Survival in patients with peak Vo2 of > 14 mL.min-1.kg-1 (88%) was not different from that of patients with peak Vo2 of < or = 14 mL.min-1.kg-1 (79%) (P = NS). However, survival was worse in patients with peak Vo2 of < or = 10 mL.min-1.kg-1 (52%) versus those with peak Vo2 of > 10 mL.min-1.kg-1 (89%) (P < .0001). By Cox regression analysis, exercise CO response was the strongest independent predictor of survival (risk ratio, 4.3), with peak Vo2 dichotomized at 10 mL. min-1.kg-1 (risk ratio, 3.3) as the only other independent predictor. Patients with reduced CO responses and peak Vo2 of < or = 10 mL.min-1.kg-1 had an extremely poor 1-year survival rate (38%). Both CO response to exercise and peak exercise Vo2 provide valuable independent prognostic information in ambulatory patients with heart failure. These variables should be used in combination to select potential heart transplantation candidates.

Road transport and diet affect metabolic response to exercise in horses.

PubMed

Connysson, M; Muhonen, S; Jansson, A

2017-11-01

This study investigated the effects of transport and diet on metabolic response during a subsequent race-like test in Standardbred horses in training fed a forage-only diet and a 50:50 forage:oats diet. Six trained and raced Standardbred trotter mares were used. Two diets, 1 forage-only diet (FONLY) and 1 diet with 50% of DM intake from forage and 50% from oats (FOATS), were fed for two 29-d periods in a crossover design. At Day 21, the horses were subjected to transport for 100 km before and after they performed an exercise test (transport test [TT]). At Day 26, the horses performed a control test (CT), in which they were kept in their stall before and after the exercise test. Blood samples were collected throughout the study, and heart rate and water intake were recorded. Heart rate and plasma cortisol, glucose, and NEFA concentrations were greater for the TT than for the CT ( = 0.008, = 0.020, = 0.010, and = 0.0002, respectively) but were not affected by diet. Plasma acetate concentration was lower during the TT than during the CT ( = 0.034) and greater for the FONLY than for the FOATS ( = 0.003). There were no overall effects of the TT compared with the CT on total plasma protein concentration (TPP), but TPP was lower with the FONLY than with the FOATS ( = 0.016). There was no overall effect of the TT compared with the CT on water intake, but water intake was greater with the FONLY than the FOATS ( = 0.011). There were no overall effects of transport or diet on BW, plasma lactate, or plasma urea concentration. It was concluded that both transport and diet affect metabolic response during exercise in horses. Aerobic energy supply was most likely elevated by transportation and by the FONLY. The FONLY also decreased exercise-induced effects on extracellular fluid regulation. These results highlight the importance of experimental design in nutrition studies. If the aim is to examine how a diet affects exercise response in competition horses, transport should preferably be included in the experimental design, because horses are likely to be transported before a competition.

Effects of acute aerobic exercise on neural correlates of attention and inhibition in adolescents with bipolar disorder

PubMed Central

Metcalfe, A W S; MacIntosh, B J; Scavone, A; Ou, X; Korczak, D; Goldstein, B I

2016-01-01

Executive dysfunction is common during and between mood episodes in bipolar disorder (BD), causing social and functional impairment. This study investigated the effect of acute exercise on adolescents with BD and healthy control subjects (HC) to test for positive or negative consequences on neural response during an executive task. Fifty adolescents (mean age 16.54±1.47 years, 56% female, 30 with BD) completed an attention and response inhibition task before and after 20 min of recumbent cycling at ~70% of age-predicted maximum heart rate. 3 T functional magnetic resonance imaging data were analyzed in a whole brain voxel-wise analysis and as regions of interest (ROI), examining Go and NoGo response events. In the whole brain analysis of Go trials, exercise had larger effect in BD vs HC throughout ventral prefrontal cortex, amygdala and hippocampus; the profile of these effects was of greater disengagement after exercise. Pre-exercise ROI analysis confirmed this 'deficit in deactivation' for BDs in rostral ACC and found an activation deficit on NoGo errors in accumbens. Pre-exercise accumbens NoGo error activity correlated with depression symptoms and Go activity with mania symptoms; no correlations were present after exercise. Performance was matched to controls and results survived a series of covariate analyses. This study provides evidence that acute aerobic exercise transiently changes neural response during an executive task among adolescents with BD, and that pre-exercise relationships between symptoms and neural response are absent after exercise. Acute aerobic exercise constitutes a biological probe that may provide insights regarding pathophysiology and treatment of BD. PMID:27187236

Bed rest attenuates sympathetic and pressor responses to isometric exercise in antigravity leg muscles in humans.

PubMed

Kamiya, Atsunori; Michikami, Daisaku; Shiozawa, Tomoki; Iwase, Satoshi; Hayano, Junichiro; Kawada, Toru; Sunagawa, Kenji; Mano, Tadaaki

2004-05-01

Although spaceflight and bed rest are known to cause muscular atrophy in the antigravity muscles of the legs, the changes in sympathetic and cardiovascular responses to exercises using the atrophied muscles remain unknown. We hypothesized that bed rest would augment sympathetic responses to isometric exercise using antigravity leg muscles in humans. Ten healthy male volunteers were subjected to 14-day 6 degrees head-down bed rest. Before and after bed rest, they performed isometric exercises using leg (plantar flexion) and forearm (handgrip) muscles, followed by 2-min postexercise muscle ischemia (PEMI) that continues to stimulate the muscle metaboreflex. These exercises were sustained to fatigue. We measured muscle sympathetic nerve activity (MSNA) in the contralateral resting leg by microneurography. In both pre- and post-bed-rest exercise tests, exercise intensities were set at 30 and 70% of the maximum voluntary force measured before bed rest. Bed rest attenuated the increase in MSNA in response to fatiguing plantar flexion by approximately 70% at both exercise intensities (both P < 0.05 vs. before bed rest) and reduced the maximal voluntary force of plantar flexion by 15%. In contrast, bed rest did not alter the increase in MSNA response to fatiguing handgrip and had no effects on the maximal voluntary force of handgrip. Although PEMI sustained MSNA activation before bed rest in all trials, bed rest entirely eliminated the PEMI-induced increase in MSNA in leg exercises but partially attenuated it in forearm exercises. These results do not support our hypothesis but indicate that bed rest causes a reduction in isometric exercise-induced sympathetic activation in (probably atrophied) antigravity leg muscles.

Dose-Response Effects of Aerobic Exercise on Quality of Life in Postmenopausal Women: Results from the Breast Cancer and Exercise Trial in Alberta (BETA).

PubMed

Courneya, Kerry S; McNeil, Jessica; O'Reilly, Rachel; Morielli, Andria R; Friedenreich, Christine M

2017-06-01

Exercise generally improves quality of life (QoL) and psychosocial functioning in adult populations but few randomized trials have examined dose-response effects. The purpose of the present study was to report the QoL and psychosocial outcomes from the Breast Cancer and Exercise Trial in Alberta (BETA). Healthy but inactive postmenopausal women at risk for breast cancer were randomized to a year-long aerobic exercise intervention consisting of either 150 min/week (moderate volume group, n = 200) or 300 min/week (high volume group, n = 200). QoL was assessed at baseline and 1 year using the short form-36 health survey. Sleep quality, depression, anxiety, stress, self-esteem, and happiness were also assessed. Participant preference for group assignment (i.e., exercise volume) was assessed at baseline and tested as a moderator. There were no statistically significant dose-response effects of aerobic exercise on any QoL, sleep quality, or psychosocial outcome. Participant preference for group assignment did not moderate any QoL, sleep quality, or psychosocial responses. Marital status was a significant moderator (p for interaction = 0.01) and obesity showed a trend towards being a moderator (p for interaction = 0.08) of the dose-response effects of aerobic exercise on global sleep quality such that unmarried and obese women improved sleep quality with the higher volume of aerobic exercise. A higher volume of aerobic exercise, approximately double the minimum public health guideline, did not provide additional QoL or psychosocial benefits compared to the minimum public health guideline in inactive postmenopausal women, even for women who preferred the higher volume of exercise at baseline. Trial Registration clinicaltrials.gov identifier: NCT1435005.

Effects of acute aerobic exercise on neural correlates of attention and inhibition in adolescents with bipolar disorder.

PubMed

Metcalfe, A W S; MacIntosh, B J; Scavone, A; Ou, X; Korczak, D; Goldstein, B I

2016-05-17

Executive dysfunction is common during and between mood episodes in bipolar disorder (BD), causing social and functional impairment. This study investigated the effect of acute exercise on adolescents with BD and healthy control subjects (HC) to test for positive or negative consequences on neural response during an executive task. Fifty adolescents (mean age 16.54±1.47 years, 56% female, 30 with BD) completed an attention and response inhibition task before and after 20 min of recumbent cycling at ~70% of age-predicted maximum heart rate. 3 T functional magnetic resonance imaging data were analyzed in a whole brain voxel-wise analysis and as regions of interest (ROI), examining Go and NoGo response events. In the whole brain analysis of Go trials, exercise had larger effect in BD vs HC throughout ventral prefrontal cortex, amygdala and hippocampus; the profile of these effects was of greater disengagement after exercise. Pre-exercise ROI analysis confirmed this 'deficit in deactivation' for BDs in rostral ACC and found an activation deficit on NoGo errors in accumbens. Pre-exercise accumbens NoGo error activity correlated with depression symptoms and Go activity with mania symptoms; no correlations were present after exercise. Performance was matched to controls and results survived a series of covariate analyses. This study provides evidence that acute aerobic exercise transiently changes neural response during an executive task among adolescents with BD, and that pre-exercise relationships between symptoms and neural response are absent after exercise. Acute aerobic exercise constitutes a biological probe that may provide insights regarding pathophysiology and treatment of BD.

Estrogen attenuates the cardiovascular and ventilatory responses to central command in cats.

PubMed

Hayes, Shawn G; Moya Del Pino, Nicolas B; Kaufman, Marc P

2002-04-01

Static exercise is well known to increase heart rate, arterial blood pressure, and ventilation. These increases appear to be less in women than in men, a difference that has been attributed to an effect of estrogen on neuronal function. In decerebrate male cats, we examined the effect of estrogen (17beta-estradiol; 0.001, 0.01, 0.1, and 1.0 microg/kg iv) on the cardiovascular and ventilatory responses to central command and the exercise pressor reflex, the two neural mechanisms responsible for evoking the autonomic and ventilatory responses to exercise. We found that 17beta-estradiol, in each of the three doses tested, attenuated the pressor, cardioaccelerator, and phrenic nerve responses to electrical stimulation of the mesencephalic locomotor region (i.e., central command). In contrast, none of the doses of 17beta-estradiol had any effect on the pressor, cardioaccelerator, and ventilatory responses to static contraction or stretch of the triceps surae muscles. We conclude that, in decerebrate male cats, estrogen injected intravenously attenuates cardiovascular and ventilatory responses to central command but has no effect on responses to the exercise pressor reflex.

Neurovascular control during exercise in acute coronary syndrome patients with Gln27Glu polymorphism of β2-adrenergic receptor

PubMed Central

Ferreira-Santos, Larissa; Martinez, Daniel G.; Nicolau, José Carlos; Moreira, Humberto G.; Alves, Maria Janieire; Pereira, Alexandre C.; Trombetta, Ivani C.; Negrão, Carlos Eduardo

2017-01-01

Background Gln27Glu (rs1042714) polymorphism of the β2-adrenergic receptor (ADRB2) has been association with cardiovascular functionality in healthy subjects. However, it is unknown whether the presence of the ADRB2 Gln27Glu polymorphism influences neurovascular responses during exercise in patients with acute coronary syndromes (ACS). We tested the hypothesis that patients with ACS homozygous for the Gln allele would have increased muscle sympathetic nerve activity (MSNA) responses and decreased forearm vascular conductance (FVC) responses during exercise compared with patients carrying the Glu allele (Gln27Glu and Glu27Glu). In addition, exercise training would restore these responses in Gln27Gln patients. Methods and results Thirty-days after an ischemic event, 61 patients with ACS without ventricular dysfunction were divided into 2 groups: (1) Gln27Gln (n = 35, 53±1years) and (2) Gln27Glu+Glu27Glu (n = 26, 52±2years). MSNA was directly measured using the microneurography technique, blood pressure (BP) was measured with an automatic oscillometric device, and blood flow was measured using venous occlusion plethysmography. MSNA, mean BP, and FVC were evaluated at rest and during a 3-min handgrip exercise. The MSNA (P = 0.02) and mean BP (P = 0.04) responses during exercise were higher in the Gln27Gln patients compared with that in the Gln27Glu+Glu27Glu patients. No differences were found in FVC. Two months of exercise training significantly decreased the MSNA levels at baseline (P = 0.001) and in their response during exercise (P = 0.02) in Gln27Gln patients, but caused no changes in Gln27Glu+Glu27Glu patients. Exercise training increased FVC responses in Gln27Glu+Glu27Glu patients (P = 0.03), but not in Gln27Gln patients. Conclusion The exaggerated MSNA and mean BP responses during exercise suggest an increased cardiovascular risk in patients with ACS and Gln27Gln polymorphism. Exercise training emerges as an important strategy for restoring this reflex control. Gln27Glu polymorphism of ADRB2 influences exercise-induced vascular adaptation in patients with ACS. PMID:28235084

Neurovascular control during exercise in acute coronary syndrome patients with Gln27Glu polymorphism of β2-adrenergic receptor.

PubMed

Ferreira-Santos, Larissa; Martinez, Daniel G; Nicolau, José Carlos; Moreira, Humberto G; Alves, Maria Janieire; Pereira, Alexandre C; Trombetta, Ivani C; Negrão, Carlos Eduardo; Rondon, Maria Urbana P B

2017-01-01

Gln27Glu (rs1042714) polymorphism of the β2-adrenergic receptor (ADRB2) has been association with cardiovascular functionality in healthy subjects. However, it is unknown whether the presence of the ADRB2 Gln27Glu polymorphism influences neurovascular responses during exercise in patients with acute coronary syndromes (ACS). We tested the hypothesis that patients with ACS homozygous for the Gln allele would have increased muscle sympathetic nerve activity (MSNA) responses and decreased forearm vascular conductance (FVC) responses during exercise compared with patients carrying the Glu allele (Gln27Glu and Glu27Glu). In addition, exercise training would restore these responses in Gln27Gln patients. Thirty-days after an ischemic event, 61 patients with ACS without ventricular dysfunction were divided into 2 groups: (1) Gln27Gln (n = 35, 53±1years) and (2) Gln27Glu+Glu27Glu (n = 26, 52±2years). MSNA was directly measured using the microneurography technique, blood pressure (BP) was measured with an automatic oscillometric device, and blood flow was measured using venous occlusion plethysmography. MSNA, mean BP, and FVC were evaluated at rest and during a 3-min handgrip exercise. The MSNA (P = 0.02) and mean BP (P = 0.04) responses during exercise were higher in the Gln27Gln patients compared with that in the Gln27Glu+Glu27Glu patients. No differences were found in FVC. Two months of exercise training significantly decreased the MSNA levels at baseline (P = 0.001) and in their response during exercise (P = 0.02) in Gln27Gln patients, but caused no changes in Gln27Glu+Glu27Glu patients. Exercise training increased FVC responses in Gln27Glu+Glu27Glu patients (P = 0.03), but not in Gln27Gln patients. The exaggerated MSNA and mean BP responses during exercise suggest an increased cardiovascular risk in patients with ACS and Gln27Gln polymorphism. Exercise training emerges as an important strategy for restoring this reflex control. Gln27Glu polymorphism of ADRB2 influences exercise-induced vascular adaptation in patients with ACS.

Insulin and glucose responses during bed rest with isotonic and isometric exercise

NASA Technical Reports Server (NTRS)

Dolkas, C. B.; Greenleaf, J. E.

1977-01-01

The effects of daily intensive isotonic (68% maximum oxygen uptake) and isometric (21% maximum extension force) leg exercise on plasma insulin and glucose responses to an oral glucose tolerance test (OGTT) during 14-day bed-rest (BR) periods were investigated in seven young healthy men. The OGTT was given during ambulatory control and on day 10 of the no-exercise, isotonic, and isometric exercise BR periods during the 15-wk study. The subjects were placed on a controlled diet starting 10 days before each BR period. During BR, basal plasma glucose concentration remained unchanged with no exercise, but increased (P less 0.05) to 87-89 mg/100 ml with both exercise regimens on day 2, and then fell slightly below control levels on day 13. The fall in glucose content during BR was independent of the exercise regimen and was an adjustment for the loss of plasma volume. The intensity of the responses of insulin and glucose to the OGTT was inversely proportional to the total daily energy expenditure during BR. It was estimated that at least 1020 kcal/day must be provided by supplemental exercise to restore the hyperinsulinemia to control levels.

Muscle metabolic and neuromuscular determinants of fatigue during cycling in different exercise intensity domains

PubMed Central

Black, Matthew I.; Jones, Andrew M.; Blackwell, Jamie R.; Bailey, Stephen J.; Wylie, Lee J.; McDonagh, Sinead T. J.; Thompson, Christopher; Kelly, James; Sumners, Paul; Mileva, Katya N.; Bowtell, Joanna L.

2017-01-01

Lactate or gas exchange threshold (GET) and critical power (CP) are closely associated with human exercise performance. We tested the hypothesis that the limit of tolerance (Tlim) during cycle exercise performed within the exercise intensity domains demarcated by GET and CP is linked to discrete muscle metabolic and neuromuscular responses. Eleven men performed a ramp incremental exercise test, 4–5 severe-intensity (SEV; >CP) constant-work-rate (CWR) tests until Tlim, a heavy-intensity (HVY; GET) CWR test until Tlim, and a moderate-intensity (MOD; 0.05) muscle metabolic milieu (i.e., low pH and [PCr] and high [lactate]) was attained at Tlim (approximately 2–14 min) for all SEV exercise bouts. The muscle metabolic perturbation was greater at Tlim following SEV compared with HVY, and also following SEV and HVY compared with MOD (all P < 0.05). The normalized M-wave amplitude for the vastus lateralis (VL) muscle decreased to a similar extent following SEV (−38 ± 15%), HVY (−68 ± 24%), and MOD (−53 ± 29%), (P > 0.05). Neural drive to the VL increased during SEV (4 ± 4%; P < 0.05) but did not change during HVY or MOD (P > 0.05). During SEV and HVY, but not MOD, the rates of change in M-wave amplitude and neural drive were correlated with changes in muscle metabolic ([PCr], [lactate]) and blood ionic/acid-base status ([lactate], [K+]) (P < 0.05). The results of this study indicate that the metabolic and neuromuscular determinants of fatigue development differ according to the intensity domain in which the exercise is performed. NEW & NOTEWORTHY The gas exchange threshold and the critical power demarcate discrete exercise intensity domains. For the first time, we show that the limit of tolerance during whole-body exercise within these domains is characterized by distinct metabolic and neuromuscular responses. Fatigue development during exercise greater than critical power is associated with the attainment of consistent “limiting” values of muscle metabolites, whereas substrate availability and limitations to muscle activation may constrain performance at lower intensities. PMID:28008101

Exercise capacity is associated with endothelin-1 release during emotional excitement in coronary artery disease patients.

PubMed

Tulppo, Mikko P; Piira, Olli-Pekka; Hautala, Arto J; Kiviniemi, Antti M; Miettinen, Johanna A; Huikuri, Heikki V

2014-08-01

Endothelin-1 (ET-1), a potent vasoconstrictor, IL-6, and catecholamines are increased and heart rate variability [SD of normal to normal R-R intervals (SDNN)] decreased during emotional excitement, but individual responses vary. We tested the hypothesis that exercise capacity is associated with physiological responses caused by real-life emotional excitement. We measured the plasma levels of ET-1, IL-6, catecholamines, heart rate, and SDNN in enthusiastic male ice hockey spectators (n = 51; age, 59 ± 9 years) with stable coronary artery disease (CAD) at baseline and during the Finnish National Ice Hockey League's final play-off matches. Maximal exercise capacity (METs) by bicycle exercise test and left ventricular ejection fraction (LVEF) were measured on a separate day. ET-1 response from baseline to emotional excitement correlated with maximal METs (r = -0.30; P = 0.040). In a linear stepwise regression analysis age, body mass index (BMI), METs, LVEF, basal ET-1, and subjective experience of excitement were entered the model as independent variables to explain ET-1 response. This model explained 27% of ET-1 response (P = 0.003). Maximal METs were most strongly correlated with ET-1 response (β = -0.45; partial correlation r = -0.43; P = 0.002), followed by BMI (β = -0.31; partial correlation r = -0.31; P = 0.033) and LVEF (β = -0.30; partial correlation r = -0.33; P = 0.023). Exercise capacity may protect against further cardiovascular events in CAD patients, because it is associated with reduced ET-1 release during emotional excitement. Copyright © 2014 the American Physiological Society.

Mental stress-induced ischemia in patients with coronary artery disease: echocardiographic characteristics and relation to exercise-induced ischemia.

PubMed

Stepanovic, Jelena; Ostojic, Miodrag; Beleslin, Branko; Vukovic, Olivera; Djordjevic-Dikic, Ana; Dikic, Ana Djordjevic; Giga, Vojislav; Nedeljkovic, Ivana; Nedeljkovic, Milan; Stojkovic, Sinisa; Vukcevic, Vladan; Dobric, Milan; Petrasinovic, Zorica; Marinkovic, Jelena; Lecic-Tosevski, Dusica

2012-09-01

The aims of this study were to investigate the incidence and parameters associated with myocardial ischemia during mental stress (MS) as measured by echocardiography and to evaluate the relation between MS-induced and exercise-induced myocardial ischemia. Study participants were 79 patients (63 men; mean [M] [standard deviation {SD}] age = 52 [8] years) with angiographically confirmed coronary artery disease and previous positive exercise test result. The MS protocol consisted of mental arithmetic and anger recall task. The patients performed a treadmill exercise test 15 to 20 minutes after the MS task. Data of post-MS exercise were compared with previous exercise stress test results. The frequency of echocardiographic abnormalities was 35% in response to the mental arithmetic task, compared with 61% with anger recall and 96% with exercise (p < .001, exercise versus MS). Electrocardiogram abnormalities and chest pain were substantially less common during MS than were echocardiographic abnormalities. Independent predictors of MS-induced myocardial ischemia were: wall motion score index at rest (p = .02), peak systolic blood pressure (p = .005), and increase in rate-pressure product (p = .004) during MS. The duration of exercise stress test was significantly shorter (p < .001) when MS preceded the exercise and in the case of earlier exercise (M [SD] = 4.4 [1.9] versus 6.7 [2.2] minutes for patients positive on MS and 5.7 [1.9] versus 8.0 [2.3] minutes for patients negative on MS). Echocardiography can be successfully used to document myocardial ischemia induced by MS. MS-induced ischemia was associated with an increase in hemodynamic parameters during MS and worse function of the left ventricle. MS may shorten the duration of subsequent exercise stress testing and can potentiate exercise-induced ischemia in susceptible patients with coronary artery disease.

Does repeated and heavy exercise impair blood rheology in carriers of sickle cell trait?

PubMed

Tripette, Julien; Hardy-Dessources, Marie-Dominique; Sara, Fagnété; Montout-Hedreville, Mona; Saint-Martin, Christian; Hue, Olivier; Connes, Philippe

2007-11-01

To determine if the time courses of hemorheologic parameters are different between carriers of sickle cell trait (SCT) and subjects with normal hemoglobin in response to exercise. Observational and comparative study. Testing was conducted in a laboratory of exercise physiology. Nine carriers of sickle cell trait (SCT group) and 7 subjects with normal hemoglobin (CONT group) performed an exercise protocol of the repetition of 3 successive maximal ramp exercise tests. Blood was sampled at rest (TR), at the end of each of the 3 tests (T1, T2, T3), and during the immediate (T2h) and late (T24h, T48h) recovery periods. Blood and plasma viscosity (etab and etap, respectively), hematocrit (Hct), and red blood cell (RBC) rigidity (Tk and k indexes) were determined. In both groups, etab significantly increased in response to exercise but the SCT group had significantly higher etab at T3 and T2h. etab then returned to baseline value at T2h in the CONT group and at T24h in the SCT group. Tk and k were not changed by exercise but significantly increased above baseline value in both groups at T24h and T48h. The increase in Tk and k during late recovery was higher in the SCT group than in the CONT group, indicating that SCT carriers had significantly higher RBC rigidity than the CONT group at that time. The hemorheologic changes induced by exercise in the SCT carriers could trigger microcirculatory disorders during the recovery.

Long-term effects of cardiac rehabilitation in elderly individuals with stable coronary artery disease.

PubMed

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

2016-01-01

To compare exercise capacity and cardiovascular response to exercise in elderly individuals with coronary artery disease (CAD) who attend ongoing community-based maintenance cardiac rehabilitation (CR) versus age- and gender-matched healthy "very active" (HVA; ≥ 2000 kcal/week) and healthy "less active" (HLA; <2000 kcal/week) individuals. Sixty-three participants (age: 72.3 ± 5.1 years; 62% men; n = 21 per group) completed the following assessments: (1) symptom-limited graded exercise test with expired gas analysis and bioimpedance assessment of cardiovascular function during exercise; (2) walking tests; (3) physical function; (4) anthropometry and (5) 12-month physical activity recall. The CR group achieved 98% (range: 73-154%) of age- and gender-predicted peak oxygen consumption for healthy individuals. Peak oxygen consumption was lower in CR compared to HVA but not HLA group (VO2peak: CR: 19.0 ± 4.5, HVA: 23.7 ± 2.9, HLA: 20.7 ± 4.7 ml ·kg(-1)ċmin(-1), p = 0.001 versus HVA; p = 0.390 versus HLA). Peak heart rate was lower in CR compared to both HVA and HLA. Walking test results and cardiovascular and physical function were not different between the groups. Elderly individuals with CAD participating in maintenance CR have similar exercise capacity and cardiorespiratory response to exercise compared to their age- and gender-matched less active healthy peers. The findings support referral of elderly patients to community-based CR. Fitness benefits of long-term maintenance cardiac rehabilitation (CR) programs remain unknown. Elderly individuals with coronary artery disease participating in maintenance CR have exercise capacity and cardiorespiratory response to exercise similar to their less active healthy peers. Maintenance CR may play an important role prolonging independent living in elderly individuals.

Effect of ageing on hypoxic exercise cardiorespiratory, muscle and cerebral oxygenation responses in healthy humans.

PubMed

Puthon, Lara; Bouzat, Pierre; Robach, Paul; Favre-Juvin, Anne; Doutreleau, Stéphane; Verges, Samuel

2017-04-01

What is the central question of this study? This study aimed to determine the effect of ageing on cardiorespiratory and tissue oxygenation responses to hypoxia during maximal incremental exercise. What is the main finding and its importance? Older healthy subjects had preserved hypoxic cardiorespiratory and tissue oxygenation responses at rest and during moderate exercise. At maximal exercise, they had a reduced hypoxic ventilatory response but similar maximal power output reduction compared with young individuals. This study suggests that until moderate exercise, hypoxic responses are preserved until the age of 70 years and therefore that ageing is not a contraindication for high-altitude sojourn. This study assessed the effects of ageing on cardiorespiratory and tissue oxygenation responses to hypoxia both at rest and during incremental maximal exercise. Sixteen young (20-30 years old) and 15 older healthy subjects (60-70 years old) performed two maximal incremental cycling tests in normoxia and hypoxia (inspiratory oxygen fraction 12%). Cardiorespiratory responses, prefrontal cortex and quadriceps tissue oxygenation (near-infrared spectroscopy) were measured during exercise as well as during hypercapnia at rest. The hypoxic ventilatory response was similar in young compared with older individuals at rest and during moderate-intensity exercise (50% maximal power output: young 0.9 ± 0.2 versus older 1.1 ± 0.8 l min -1  % -1 ; P > 0.05) but larger in young subjects during high-intensity exercise (maximal power output: 2.2 ± 0.8 versus 1.8 ± 1.1 l min -1  % -1 ; P < 0.05). The hypoxic cardiac response did not differ between groups both at rest and during exercise. During exercise in hypoxia, young subjects showed greater deoxygenation than older subjects, at both the prefrontal cortex and quadriceps levels. The hypoxia-induced reduction in maximal power output (young -32 ± 5% versus older -30 ± 6%; P > 0.05) and the hypercapnic responses did not differ between groups. Older healthy and active individuals below the age of 70 years have cardiorespiratory and tissue oxygenation responses to hypoxia similar to young individuals both at rest and during moderate-intensity exercise. Despite a lower hypoxic ventilatory response at maximal exercise, older individuals have similar oxygen desaturation and maximal power output reduction compared with young subjects. © 2017 The Authors. Experimental Physiology © 2017 The Physiological Society.

The Positive Effects of Priming Exercise on Oxygen Uptake Kinetics and High-Intensity Exercise Performance Are Not Magnified by a Fast-Start Pacing Strategy in Trained Cyclists

PubMed Central

Caritá, Renato Aparecido Corrêa; Greco, Camila Coelho; Denadai, Benedito Sérgio

2014-01-01

The purpose of this study was to determine both the independent and additive effects of prior heavy-intensity exercise and pacing strategies on the VO2 kinetics and performance during high-intensity exercise. Fourteen endurance cyclists (VO2max  = 62.8±8.5 mL.kg−1.min−1) volunteered to participate in the present study with the following protocols: 1) incremental test to determine lactate threshold and VO2max; 2) four maximal constant-load tests to estimate critical power; 3) six bouts of exercise, using a fast-start (FS), even-start (ES) or slow-start (SS) pacing strategy, with and without a preceding heavy-intensity exercise session (i.e., 90% critical power). In all conditions, the subjects completed an all-out sprint during the final 60 s of the test as a measure of the performance. For the control condition, the mean response time was significantly shorter (p<0.001) for FS (27±4 s) than for ES (32±5 s) and SS (32±6 s). After the prior exercise, the mean response time was not significantly different among the paced conditions (FS = 24±5 s; ES = 25±5 s; SS = 26±5 s). The end-sprint performance (i.e., mean power output) was only improved (∼3.2%, p<0.01) by prior exercise. Thus, in trained endurance cyclists, an FS pacing strategy does not magnify the positive effects of priming exercise on the overall VO2 kinetics and short-term high-intensity performance. PMID:24740278

Battery of Candidate Physical Tests for Consideration as Occupational Physical Selection Standards for Canadian Forces Trades,

DTIC Science & Technology

1981-07-01

causes a response of the cardio-pulmonary functions similar to that induced by treadmill and bicycle ergometer exercise (89,90). Therefore, a measure of...Flow, and the Blood Pressure and Heart Rate Response to Isometric Exercise . Saint Louis Uni., AFOSR- TR-75-0086, 1974. 51. T.M. PRINTY. A...relationship between the muscle or muscle group and the corresponding lever system responsible for a given movement. Second, the restrictions of the

Evaluation of aortic elastic properties in patients with exaggerated systolic blood pressure response to exercise testing.

PubMed

Kilicaslan, Baris; Eren, Nihan Kahya; Nazlı, Cem

2015-01-01

We aimed to evaluate the aortic elastic properties in subjects with hypertensive response to exercise stress test (HRE). Sixty-six patients were divided into two groups (33 patients in HRE group and 33 patients in normotensive group). Baseline demographic characteristics were similar. The mean aortic stiffness index (ASI) was significantly higher (p=0.001) whereas aortic distensibility (AD) was significantly lower (p=0.029) in patients suggesting HRE. The C-reactive protein levels of patients with HRE was higher in the HRE group (p=0.03). AD was significantly correlated with age (r=-0.406, p<0.001), pre-test systolic blood presure (SBP) (r=-0.427, p<0.001), peak exercise SBP (r=-0.307, p=0.01), peak exercise diastolic blood presure (DBP) (r=-0.315, p=0.008), and recovery time (3 min) SBP (r=-0.497, p=0.004). Age (β=-0.506, p=0.003) and peak DBP (β=-0.322, p=0.049) were independent predictors of decreased AD. In conclusion, we found a deterioration in arterial elastic properties in patients with HRE.

Voluntary exercise offers anxiolytic potential and amplifies galanin gene expression in the locus coeruleus of the rat

PubMed Central

Sciolino, Natale R.; Dishman, Rodney K.; Holmes, Philip V.

2012-01-01

Although exercise improves anxiety in humans, it is controversial whether exercise is anxiolytic in rodents. We tested the hypothesis that stress influences the effect of exercise on anxiety-like and defensive behaviors. To explore the neurobiological mechanisms of exercise, we also examined whether exercise alters gene expression for the stress-related peptide galanin. Rats were housed in the presence or absence of a running wheel for 21 d. A subset of these rats were (1) not injected or received a single high, dose of the β-carboline FG7142 (inverse agonist at the benzodiazepine receptor site) immediately prior to testing or (2) were injected repeatedly with vehicle or FG7142 during the last 10 d of exercise. On day 22, anxiety-like and defensive behaviors were measured in the elevated plus maze, shock probe defensive burying, and defensive withdrawal tests. Locus coeruleus prepro-galanin mRNA was measured by in situ hybridization. Exercise and sedentary rats that were not injected exhibited similar behavior in all tests, whereas FG7142 injected immediately prior to the test battery produced intense avoidance and immobility consistent with an anxiety-like response. However, exercise produced anxiolytic-like and active defensive behaviors in the test battery relative to the sedentary condition in rats injected repeatedly with vehicle or FG7142. Exercise also increased prepro-galanin mRNA in the locus coeruleus relative to sedentary controls. These data suggest that the emergence of enhanced adaptive behavior after chronic voluntary exercise is influenced by stress. Our data support a role for galanin in the beneficial consequences of wheel running. PMID:22580167

Knee-joint proprioception during 30-day 6 degrees head-down bed rest with isotonic and isokinetic exercise training

NASA Technical Reports Server (NTRS)

Bernauer, E. M.; Walby, W. F.; Ertl, A. C.; Dempster, P. T.; Bond, M.; Greenleaf, J. E.

1994-01-01

To determine if daily isotonic exercise or isokinetic exercise training coupled with daily leg proprioceptive training, would influence leg proprioceptive tracking responses during bed rest (BR), 19 men (36 +/- SD 4 years, 178 +/- 7 cm, 76.8 +/- 7.8 kg) were allocated into a no-exercise (NOE) training control group (n = 5), and isotonic exercise (ITE, n = 7) and isokinetic exercise (IKE, n = 7) training groups. Exercise training was conducted during BR for two 30-min periods.d-1, 5 d.week-1. Only the IKE group performed proprioceptive training using a new isokinetic procedure with each lower extremity for 2.5 min before and after the daily exercise training sessions; proprioceptive testing occurred weekly for all groups. There were no significant differences in proprioceptive tracking scores, expressed as a percentage of the perfect score of 100, in the pre-BR ambulatory control period between the three groups. Knee extension and flexion tracking responses were unchanged with NOE during BR, but were significantly greater (*p < 0.05) at the end of BR in both exercise groups when compared with NOE responses (extension: NOE 80.7 +/- 0.7%, ITE 82.9* +/- 0.6%, IKE 86.5* +/- 0.7%; flexion: NOE 77.6 +/- 1.5%, ITE 80.0 +/- 0.8% (NS), IKE 83.6* +/- 0.8%). Although proprioceptive tracking was unchanged during BR with NOE, both isotonic exercise training (without additional proprioceptive training) and especially isokinetic exercise training when combined with daily proprioceptive training, significantly improved knee proprioceptive tracking responses after 30 d of BR.

Knee-joint proprioception during 30-day 6 degrees head-down bed rest with isotonic and isokinetic exercise training.

PubMed

Bernauer, E M; Walby, W F; Ertl, A C; Dempster, P T; Bond, M; Greenleaf, J E

1994-12-01

To determine if daily isotonic exercise or isokinetic exercise training coupled with daily leg proprioceptive training, would influence leg proprioceptive tracking responses during bed rest (BR), 19 men (36 +/- SD 4 years, 178 +/- 7 cm, 76.8 +/- 7.8 kg) were allocated into a no-exercise (NOE) training control group (n = 5), and isotonic exercise (ITE, n = 7) and isokinetic exercise (IKE, n = 7) training groups. Exercise training was conducted during BR for two 30-min periods.d-1, 5 d.week-1. Only the IKE group performed proprioceptive training using a new isokinetic procedure with each lower extremity for 2.5 min before and after the daily exercise training sessions; proprioceptive testing occurred weekly for all groups. There were no significant differences in proprioceptive tracking scores, expressed as a percentage of the perfect score of 100, in the pre-BR ambulatory control period between the three groups. Knee extension and flexion tracking responses were unchanged with NOE during BR, but were significantly greater (*p < 0.05) at the end of BR in both exercise groups when compared with NOE responses (extension: NOE 80.7 +/- 0.7%, ITE 82.9* +/- 0.6%, IKE 86.5* +/- 0.7%; flexion: NOE 77.6 +/- 1.5%, ITE 80.0 +/- 0.8% (NS), IKE 83.6* +/- 0.8%). Although proprioceptive tracking was unchanged during BR with NOE, both isotonic exercise training (without additional proprioceptive training) and especially isokinetic exercise training when combined with daily proprioceptive training, significantly improved knee proprioceptive tracking responses after 30 d of BR.

Knee-Joint Proprioception During 30-Day 6 deg Head-Down Bed Rest with Isotonic and Isokinetic Exercise Training

NASA Technical Reports Server (NTRS)

Bernauer, E. M.; Walby, W. F.; Ertl, A. C.; Dempster, P. T.; Bond, M.; Greenleaf, J. E.

1994-01-01

To determine if daily isotonic exercise or isokinetic exercise training coupled with daily log proprioceptive training, would influence log proprioceptive tracking responses during Bed Rest (BR), 19 men (36 +/- SD 4 years, 178 +/- 7 cm, 76.8 +/- 7.8 kg) were allocated into a NO-Exercise (NOE) training control group (n = 5), and IsoTanic Exercise (ITE, n = 7) and IsoKinetic Exercise (IKE, n = 7) training groups. Exercise training was conducted during BR for two 30-min period / d, 5 d /week. Only the IKE group performed proprioceptive training using a now isokinetic procedure with each lower extremity for 2.5 min before and after the daily exercise training sessions; proprioceptive testing occurred weekly for all groups. There were no significant differences in proprioceptive tracking scores, expressed as a percentage of the perfect score of 100, in the pro-BR ambulatory control period between the three groups. Knee extension and flexion tracking responses were unchanged with NOE during BR, but were significantly greater (*p less than 0.05) at the end of BR in both exercise groups when compared with NOE responses (extension: NOE 80.7 +/- 0.7%, ITE 82.9 +/- 0.6%, IKE 86.5* +/- 0.7%; flexion: NOE 77.6 +/- 1.50, ITE 80.0 +/- 0.8% (NS), IKE 83.6* +/- 0.8%). Although proprioceptive tracking was unchanged during BR with NOE, both lsotonic exercise training (without additional propriaceptive training) and especially isokinetic exercise training when combined with daily proprioceptive training, significantly improved knee proprioceptive tracking responses after 30 d of BR.

Long-term moderate treadmill exercise promotes stress-coping strategies in male and female rats.

PubMed

Lalanza, Jaume F; Sanchez-Roige, Sandra; Cigarroa, Igor; Gagliano, Humberto; Fuentes, Silvia; Armario, Antonio; Capdevila, Lluís; Escorihuela, Rosa M

2015-11-05

Recent evidence has revealed the impact of exercise in alleviating anxiety and mood disorders; however, the exercise protocol that exerts such benefit is far from known. The current study was aimed to assess the effects of long-term moderate exercise on behavioural coping strategies (active vs. passive) and Hypothalamic-Pituitary-Adrenal response in rats. Sprague-Dawley male and female rats were exposed to 32-weeks of treadmill exercise and then tested for two-way active avoidance learning (shuttle-box). Two groups were used as controls: a non-handled sedentary group, receiving no manipulation, and a control group exposed to a stationary treadmill. Female rats displayed shorter escape responses and higher number of avoidance responses, reaching criterion for performance earlier than male rats. In both sexes, exercise shortened escape latencies, increased the total number of avoidances and diminished the number of trials needed to reach criterion for performance. Those effects were greater during acquisition in female rats, but remained over the shuttle-box sessions in treadmill trained male rats. In females, exercise did not change ACTH and corticosterone levels after shuttle-box acquisition. Collectively, treadmill exercise improved active coping strategies in a sex-dependent manner. In a broader context, moderate exercise could serve as a therapeutic intervention for anxiety and mood disorders.

Long-term moderate treadmill exercise promotes stress-coping strategies in male and female rats

PubMed Central

Lalanza, Jaume F.; Sanchez-Roige, Sandra; Cigarroa, Igor; Gagliano, Humberto; Fuentes, Silvia; Armario, Antonio; Capdevila, Lluís; Escorihuela, Rosa M.

2015-01-01

Recent evidence has revealed the impact of exercise in alleviating anxiety and mood disorders; however, the exercise protocol that exerts such benefit is far from known. The current study was aimed to assess the effects of long-term moderate exercise on behavioural coping strategies (active vs. passive) and Hypothalamic-Pituitary-Adrenal response in rats. Sprague-Dawley male and female rats were exposed to 32-weeks of treadmill exercise and then tested for two-way active avoidance learning (shuttle-box). Two groups were used as controls: a non-handled sedentary group, receiving no manipulation, and a control group exposed to a stationary treadmill. Female rats displayed shorter escape responses and higher number of avoidance responses, reaching criterion for performance earlier than male rats. In both sexes, exercise shortened escape latencies, increased the total number of avoidances and diminished the number of trials needed to reach criterion for performance. Those effects were greater during acquisition in female rats, but remained over the shuttle-box sessions in treadmill trained male rats. In females, exercise did not change ACTH and corticosterone levels after shuttle-box acquisition. Collectively, treadmill exercise improved active coping strategies in a sex-dependent manner. In a broader context, moderate exercise could serve as a therapeutic intervention for anxiety and mood disorders. PMID:26538081

Exercise testing in asymptomatic severe aortic stenosis.

PubMed

Magne, Julien; Lancellotti, Patrizio; Piérard, Luc A

2014-02-01

The management and the clinical decision making in asymptomatic patients with aortic stenosis are challenging. An "aggressive" management, including early aortic valve replacement, is debated in these patients. However, the optimal timing for surgery remains controversial due to the lack of prospective data on the determinants of aortic stenosis progression, multicenter studies on risk stratification, and randomized studies on patient management. Exercise stress testing with or without imaging is strictly contraindicated in symptomatic patients with severe aortic stenosis. Exercise stress test is now recommended by current guidelines in asymptomatic patients and may provide incremental prognostic value. Indeed, the development of symptoms during exercise or an abnormal blood pressure response are associated with poor outcome and should be considered as an indication for surgery, as suggested by the most recently updated European Society of Cardiology 2012 guidelines. Exercise stress echocardiography may also improve the risk stratification and identify asymptomatic patients at higher risk of a cardiac event. When the test is combined with imaging, echocardiography during exercise should be recommended rather than post-exercise echocardiography. During exercise, an increase >18 to 20 mm Hg in mean pressure gradient, absence of improvement in left ventricular ejection fraction (i.e., absence of contractile reserve), and/or a systolic pulmonary arterial pressure >60 mm Hg (i.e., exercise pulmonary hypertension) are suggestive signs of advanced stages of the disease and impaired prognosis. Hence, exercise stress test may identify resting asymptomatic patients who develop exercise abnormalities and in whom surgery is recommended according to current guidelines. Exercise stress echocardiography may further unmask a subset of asymptomatic patients (i.e., without exercise stress test abnormalities) who are at high risk of reduced cardiac event free survival. In these patients, early surgery could be beneficial, whereas regular follow-up seems more appropriate in patients without echocardiographic abnormalities during exercise. Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Exercise hemodynamics in Parkinson's disease and autonomic dysfunction.

PubMed

Low, David A; Vichayanrat, Ekawat; Iodice, Valeria; Mathias, Christopher J

2014-05-01

To clarify the characteristics of hemodynamic responses to exercise and orthostasis in Parkinson's disease patients, especially those with autonomic failure. Clinical audit of supine cycling exercise test data (with active standing tests pre- and post-exercise) of Parkinson's patients with autonomic dysfunction. 23 patients (71 ± 7 yr, 7 females) with a confirmed diagnosis of Parkinson's were identified. Group mean systolic blood pressure (SBP) fell during pre-exercise standing (-39 ± 29 mmHg, P < 0.001, 17 patients had orthostatic hypotension (OH)), while heart rate (HR) increased (+13 ± 7 beats min(-1), P < 0.001). SBP (P < 0.001) increased during exercise with a wide variation in responses. SBP increased in 13 patients (INC; +30 ± 14 mmHg) and either did not change or decreased in 10 patients (DEC -12 ± 11 mmHg, P < 0.001 vs INC). The increase in HR was not different between sub-groups (30 ± 12 vs 25 ± 10 beats min(-1), INC vs. DEC, P = 0.29). The size of the pre-exercise stand SBP reduction was greater in DEC vs INC (-64 ± 23 (10 out of 10 had OH) vs -19 ± 16 mmHg (7 out of 13 had OH), respectively, P < 0.001). The HR elevation was not different between sub-groups (13 ± 8 vs 13 ± 4 beats min(-1), DEC vs INC, P = 0.94). Post-exercise SBP/DBP were lower for both sub-groups compared to pre-exercise and the standing SBP reduction post-exercise was not greater relative to pre-exercise in either sub-group. Exercise-induced hypotension can occur in Parkinson's disease patients with autonomic failure with the magnitude of the exercise response being related to the severity of autonomic dysfunction. Exercise does not appear to worsen OH in this sample of Parkinson's patients. Copyright © 2014 Elsevier Ltd. All rights reserved.

Muscle sympathetic nerve responses to physiological changes in prostaglandin production in humans

NASA Technical Reports Server (NTRS)

Doerzbacher, K. J.; Ray, C. A.

2001-01-01

Previous studies suggest that prostaglandins may contribute to exercise-induced increases in muscle sympathetic nerve activity (MSNA). To test this hypothesis, MSNA was measured at rest and during exercise before and after oral administration of ketoprofen, a cyclooxygenase inhibitor, or placebo. Twenty-one subjects completed two bouts of graded dynamic and isometric handgrip to fatigue. Each exercise bout was followed by 2 min of postexercise muscle ischemia. The second exercise bouts were performed after 60 min of rest in which 11 subjects were given ketoprofen (300 mg) and 10 subjects received a placebo. Ketoprofen significantly lowered plasma thromboxane B(2) in the drug group (from 36 +/- 6 to 22 +/- 3 pg/ml, P < 0.04), whereas thromboxane B(2) in the placebo group increased from 40 +/- 5 to 61 +/- 9 pg/ml from trial 1 to trial 2 (P < 0.008). Ketoprofen and placebo did not change sympathetic and cardiovascular responses to dynamic handgrip, isometric handgrip, and postexercise muscle ischemia. There was no relationship between thromboxane B(2) concentrations and MSNA or arterial pressure responses during both exercise modes. The data indicate that physiological increases or decreases in prostaglandins do not alter exercise-induced increases in MSNA and arterial pressure in humans. These findings suggest that contraction-induced metabolites other than prostaglandins mediate MSNA responses to exercise in humans.

Planning and executing complex large-scale exercises.

PubMed

McCormick, Lisa C; Hites, Lisle; Wakelee, Jessica F; Rucks, Andrew C; Ginter, Peter M

2014-01-01

Increasingly, public health departments are designing and engaging in complex operations-based full-scale exercises to test multiple public health preparedness response functions. The Department of Homeland Security's Homeland Security Exercise and Evaluation Program (HSEEP) supplies benchmark guidelines that provide a framework for both the design and the evaluation of drills and exercises; however, the HSEEP framework does not seem to have been designed to manage the development and evaluation of multiple, operations-based, parallel exercises combined into 1 complex large-scale event. Lessons learned from the planning of the Mississippi State Department of Health Emergency Support Function--8 involvement in National Level Exercise 2011 were used to develop an expanded exercise planning model that is HSEEP compliant but accounts for increased exercise complexity and is more functional for public health. The Expanded HSEEP (E-HSEEP) model was developed through changes in the HSEEP exercise planning process in areas of Exercise Plan, Controller/Evaluator Handbook, Evaluation Plan, and After Action Report and Improvement Plan development. The E-HSEEP model was tested and refined during the planning and evaluation of Mississippi's State-level Emergency Support Function-8 exercises in 2012 and 2013. As a result of using the E-HSEEP model, Mississippi State Department of Health was able to capture strengths, lessons learned, and areas for improvement, and identify microlevel issues that may have been missed using the traditional HSEEP framework. The South Central Preparedness and Emergency Response Learning Center is working to create an Excel-based E-HSEEP tool that will allow practice partners to build a database to track corrective actions and conduct many different types of analyses and comparisons.

Using implicit attitudes of exercise importance to predict explicit exercise dependence symptoms and exercise behaviors.

PubMed

Forrest, Lauren N; Smith, April R; Fussner, Lauren M; Dodd, Dorian R; Clerkin, Elise M

2016-01-01

"Fast" (i.e., implicit) processing is relatively automatic; "slow" (i.e., explicit) processing is relatively controlled and can override automatic processing. These different processing types often produce different responses that uniquely predict behaviors. In the present study, we tested if explicit, self-reported symptoms of exercise dependence and an implicit association of exercise as important predicted exercise behaviors and change in problematic exercise attitudes. We assessed implicit attitudes of exercise importance and self-reported symptoms of exercise dependence at Time 1. Participants reported daily exercise behaviors for approximately one month, and then completed a Time 2 assessment of self-reported exercise dependence symptoms. Undergraduate males and females (Time 1, N = 93; Time 2, N = 74) tracked daily exercise behaviors for one month and completed an Implicit Association Test assessing implicit exercise importance and subscales of the Exercise Dependence Questionnaire (EDQ) assessing exercise dependence symptoms. Implicit attitudes of exercise importance and Time 1 EDQ scores predicted Time 2 EDQ scores. Further, implicit exercise importance and Time 1 EDQ scores predicted daily exercise intensity while Time 1 EDQ scores predicted the amount of days exercised. Implicit and explicit processing appear to uniquely predict exercise behaviors and attitudes. Given that different implicit and explicit processes may drive certain exercise factors (e.g., intensity and frequency, respectively), these behaviors may contribute to different aspects of exercise dependence.

Using implicit attitudes of exercise importance to predict explicit exercise dependence symptoms and exercise behaviors

PubMed Central

Forrest, Lauren N.; Smith, April R.; Fussner, Lauren M.; Dodd, Dorian R.; Clerkin, Elise M.

2015-01-01

Objectives ”Fast” (i.e., implicit) processing is relatively automatic; “slow” (i.e., explicit) processing is relatively controlled and can override automatic processing. These different processing types often produce different responses that uniquely predict behaviors. In the present study, we tested if explicit, self-reported symptoms of exercise dependence and an implicit association of exercise as important predicted exercise behaviors and change in problematic exercise attitudes. Design We assessed implicit attitudes of exercise importance and self-reported symptoms of exercise dependence at Time 1. Participants reported daily exercise behaviors for approximately one month, and then completed a Time 2 assessment of self-reported exercise dependence symptoms. Method Undergraduate males and females (Time 1, N = 93; Time 2, N = 74) tracked daily exercise behaviors for one month and completed an Implicit Association Test assessing implicit exercise importance and subscales of the Exercise Dependence Questionnaire (EDQ) assessing exercise dependence symptoms. Results Implicit attitudes of exercise importance and Time 1 EDQ scores predicted Time 2 EDQ scores. Further, implicit exercise importance and Time 1 EDQ scores predicted daily exercise intensity while Time 1 EDQ scores predicted the amount of days exercised. Conclusion Implicit and explicit processing appear to uniquely predict exercise behaviors and attitudes. Given that different implicit and explicit processes may drive certain exercise factors (e.g., intensity and frequency, respectively), these behaviors may contribute to different aspects of exercise dependence. PMID:26195916

Enhanced carotid-cardiac baroreflex response and elimination of orthostatic hypotension 24 hours after acute exercise in paraplegics

NASA Technical Reports Server (NTRS)

Engelke, K. A.; Shea, J. D.; Doerr, D. F.; Convertino, V. A.

1992-01-01

To test the hypothesis that an acute bout of maximal exercise can ameliorate orthostatic hypotension consequent to prolonged wheelchair confinement, we evaluated heart rate (HR), systolic (SBP) and diastolic (DBP) blood pressure responses during 15 minutes of 70 degrees head-up tilt (HUT) in 10 paraplegic subjects 24 hours after arm crank exercise designed to elicit maximal effort, and during a control (no exercise) conditions. Additionally, the carotid baroreceptor stimulus-cardiac response relationship was determined by measurement of R-R interval during external application of graded pressures to the carotid sinuses. One week separated the treatment conditions. The maximum slope of the carotid-cardiac baroreflex response was increased (p = 0.049) by exercise (6.2 +/- 1.7 msec/mmHg) compared to control (3.3 +/- 0.6). During control HUT, HR increased from 61 +/- 1 to 90 +/- 7 bpm (p = 0.001) while SBP decreased from 118 +/- 5 to 106 +/- 9 mmHg (p = 0.025). During HUT 24 hours after exercise, HR increased from 60 +/- 2 to 90 +/- 4 bpm (p = 0.001), but the reduction in SBP was essentially eliminated (116 +/- 5 to 113 +/- 5 mmHg).

Divers revisited: The ventilatory response to carbon dioxide in experienced scuba divers.

PubMed

Earing, Christopher Matthew Norton; McKeon, Damian John; Kubis, Hans-Peter

2014-05-01

To investigate the ventilatory response to CO2 in hyperoxia, hypoxia, and during exercise amongst experienced scuba divers and matched controls. Two studies were performed. The first investigated the CO2 sensitivity in rest and exercise using CO2 rebreathing in hyperoxia at a workload typical for diving with divers (n = 11) and controls (n = 11). The second study examined the respiratory drive of divers (n = 10) and controls (n = 10) whilst breathing four different gas mixtures balanced with N2 (ambient air; 25% O2/6% CO2; 13% O2; 13% O2/6% CO2) to assess the combined response to hypercapnia and moderate hypoxia. Exercise at a load typical for diving was found to have no effect on the ventilatory sensitivity to CO2 in divers (rest: 1.49 ± 0.33; exercise: 1.22 ± 0.55 [l/min × mmHg(-1)]) and controls (rest: 2.08 ± 0.71; exercise: 2.05 ± 0.98 [l/min × mmHg(-1)]) while differences in sensitivity remained between the groups. Inhalation of the four gas mixtures revealed the tested oxygen pressures caused no significant alteration in the ventilatory sensitivity to CO2 in divers and controls. Experienced divers possess a lower ventilatory response to CO2 which was not affected by exercise or the tested oxygen pressures suggesting a dominant adaptation of central CO2 sensitivity. Copyright © 2014 Elsevier Ltd. All rights reserved.

Students’ Perception of Self-Efficacy Following Medicinal Chemistry Skills Laboratory Exercises

PubMed Central

Roche, Victoria F.; Qi, Yongyue

2016-01-01

Objective. To analyze student perceptions of self-efficacy in meeting medicinal chemistry course related educational outcomes and skills following a medicinal chemistry skills laboratory. Methods. Four activities were implemented in a pharmacy skills laboratory (PSL) for second-year pharmacy students. Students (n=121) worked individually on exercises for three of the four activities. Pre/post-laboratory surveys on self-efficacy were administered. The McNemar test was performed to evaluate students’ self-efficacy above 70% related to course outcomes before and after the exercises in each activity. An independent t test was conducted to compare the mean of students’ responses on meeting course outcomes based on the 70% anchor for the perspective confidence on meeting course outcomes. Results. The post-PSL scores on all self-efficacy questions improved. The majority of students reported skill development in all exercises. Students and clinical faculty qualitative responses indicated they felt exercises were effective. Conclusion. A PSL can serve as a valuable opportunity to address course related educational outcomes and specific skill development and can help students assess their self-efficacy in meeting them. PMID:27402979

Students' Perception of Self-Efficacy Following Medicinal Chemistry Skills Laboratory Exercises.

PubMed

Alsharif, Naser Z; Roche, Victoria F; Qi, Yongyue

2016-06-25

Objective. To analyze student perceptions of self-efficacy in meeting medicinal chemistry course related educational outcomes and skills following a medicinal chemistry skills laboratory. Methods. Four activities were implemented in a pharmacy skills laboratory (PSL) for second-year pharmacy students. Students (n=121) worked individually on exercises for three of the four activities. Pre/post-laboratory surveys on self-efficacy were administered. The McNemar test was performed to evaluate students' self-efficacy above 70% related to course outcomes before and after the exercises in each activity. An independent t test was conducted to compare the mean of students' responses on meeting course outcomes based on the 70% anchor for the perspective confidence on meeting course outcomes. Results. The post-PSL scores on all self-efficacy questions improved. The majority of students reported skill development in all exercises. Students and clinical faculty qualitative responses indicated they felt exercises were effective. Conclusion. A PSL can serve as a valuable opportunity to address course related educational outcomes and specific skill development and can help students assess their self-efficacy in meeting them.

Exercise limitation, exercise testing and exercise recommendations in sickle cell anemia.

PubMed

Connes, Philippe; Machado, Roberto; Hue, Olivier; Reid, Harvey

2011-01-01

Sickle cell anemia (SCA or SS homozygous sickle cell disease) is an inherited blood disorder caused by single nucleotide substitution in the β-globin gene that renders their hemoglobin (HbS) much less soluble than normal hemoglobin (HbA) when deoxygenated. The polymerization of HbS upon deoxygenation is the basic pathophysiologic event leading to RBC sickling, hemolysis, vasoocclusion and ultimately to chronic organ damage. The metabolic changes imposed by exercise may initiate sickling and vaso-occlusive episodes. Further, in patients with SCA, exercise limitation may be related to anemia or chronic complications such as pulmonary vascular disease, congestive heart failure and chronic parenchymal lung disease. Few studies have investigated the cardiorespiratory responses of patients with SCA during either symptom-limited maximal exercise test on cyclo-ergometer or during a six minute walk test. Therefore, patients are advised to start exercise slowly and progressively, to maintain adequate hydration during and after exercise, to avoid cold exposure or sudden change in temperature, and to avoid sports associated with mechanical trauma. There are, however, lack of evidence to allow practitioners to prescribe an exercise program for patients with SCA, and individuals are usually encouraged to exercise on a symptom-limited basis. Finally, this review will also highlight the basic principles that are often used for exercise practice and could be used for exercise prescription and rehabilitation in patients with sickle cell anemia.

Influence of muscle mass and work on post-exercise glucose and insulin responses in young untrained subjects.

PubMed

Brambrink, J K; Fluckey, J D; Hickey, M S; Craig, B W

1997-11-01

The 18 h post-exercise glucose and insulin responses of six male and six female subjects were measured following one- or two-leg cycling to determine the influence of muscle mass involvement and work. Each subject performed three exercise trials on a Cybex Met 100 cycle ergometer: (1) two-leg exercise for 30 min at 60% of the two-leg VO2 max; (2) one-leg exercise for 30 min at 60% of one-leg VO2 max; and (3) one-leg exercise (one-leg TW) at 60% of the one-leg VO2 max with the total work performed equal to that of the two-leg trial (duration approximately 50 min). These trials were preceded by 2 days of inactivity and followed by an 18 h post-exercise 75 g oral glucose tolerance test (OGTT). The glucose response during the baseline OGTT demonstrated that the subjects had normal glucose tolerance with fasting serum glucose levels of 5.1 mM, and 1 and 2 h serum glucose less than 7.8 mM, respectively. The 18 h post-exercise glucose responses were significantly lower following the two-leg trial (P < 0.05), with the area under the curve values being 129.9 mM h-1 less than the resting control level. The 18 h post-exercise insulin AUC response of the two-leg trial was significantly lower than either of the one-leg responses (14.7 pM below the one-leg and 5.0 pM below the one-leg TW) but was not associated with a change in C-peptide. The 18 h post-exercise insulin levels of the one-leg and one-leg TW trials were above or near the resting control values, but were not accompanied by a significant change in C-peptide. In conclusion, the data presented here show that the amount of muscle tissue utilized during an exercise bout can influence both the glucose and insulin responses, whereas the amount of total work employed during the exercise had no effect on either of these parameters.

Reactive hyperemia is not responsible for stimulating muscle protein synthesis following blood flow restriction exercise

PubMed Central

Gundermann, David M.; Fry, Christopher S.; Dickinson, Jared M.; Walker, Dillon K.; Timmerman, Kyle L.; Drummond, Micah J.; Volpi, Elena

2012-01-01

Blood flow restriction (BFR) to contracting skeletal muscle during low-intensity resistance exercise training increases muscle strength and size in humans. However, the mechanism(s) underlying these effects are largely unknown. We have previously shown that mammalian target of rapamycin complex 1 (mTORC1) signaling and muscle protein synthesis (MPS) are stimulated following an acute bout of BFR exercise. The purpose of this study was to test the hypothesis that reactive hyperemia is the mechanism responsible for stimulating mTORC1 signaling and MPS following BFR exercise. Six young men (24 ± 2 yr) were used in a randomized crossover study consisting of two exercise trials: low-intensity resistance exercise with BFR (BFR trial) and low-intensity resistance exercise with sodium nitroprusside (SNP), a pharmacological vasodilator infusion into the femoral artery immediately after exercise to simulate the reactive hyperemia response after BFR exercise (SNP trial). Postexercise mixed-muscle fractional synthetic rate from the vastus lateralis increased by 49% in the BFR trial (P < 0.05) with no change in the SNP trial (P > 0.05). BFR exercise increased the phosphorylation of mTOR, S6 kinase 1, ribosomal protein S6, ERK1/2, and Mnk1-interacting kinase 1 (P < 0.05) with no changes in mTORC1 signaling in the SNP trial (P > 0.05). We conclude that reactive hyperemia is not a primary mechanism for BFR exercise-induced mTORC1 signaling and MPS. Further research is necessary to elucidate the cellular mechanism(s) responsible for the increase in mTOR signaling, MPS, and hypertrophy following acute and chronic BFR exercise. PMID:22362401

Reactive hyperemia is not responsible for stimulating muscle protein synthesis following blood flow restriction exercise.

PubMed

Gundermann, David M; Fry, Christopher S; Dickinson, Jared M; Walker, Dillon K; Timmerman, Kyle L; Drummond, Micah J; Volpi, Elena; Rasmussen, Blake B

2012-05-01

Blood flow restriction (BFR) to contracting skeletal muscle during low-intensity resistance exercise training increases muscle strength and size in humans. However, the mechanism(s) underlying these effects are largely unknown. We have previously shown that mammalian target of rapamycin complex 1 (mTORC1) signaling and muscle protein synthesis (MPS) are stimulated following an acute bout of BFR exercise. The purpose of this study was to test the hypothesis that reactive hyperemia is the mechanism responsible for stimulating mTORC1 signaling and MPS following BFR exercise. Six young men (24 ± 2 yr) were used in a randomized crossover study consisting of two exercise trials: low-intensity resistance exercise with BFR (BFR trial) and low-intensity resistance exercise with sodium nitroprusside (SNP), a pharmacological vasodilator infusion into the femoral artery immediately after exercise to simulate the reactive hyperemia response after BFR exercise (SNP trial). Postexercise mixed-muscle fractional synthetic rate from the vastus lateralis increased by 49% in the BFR trial (P < 0.05) with no change in the SNP trial (P > 0.05). BFR exercise increased the phosphorylation of mTOR, S6 kinase 1, ribosomal protein S6, ERK1/2, and Mnk1-interacting kinase 1 (P < 0.05) with no changes in mTORC1 signaling in the SNP trial (P > 0.05). We conclude that reactive hyperemia is not a primary mechanism for BFR exercise-induced mTORC1 signaling and MPS. Further research is necessary to elucidate the cellular mechanism(s) responsible for the increase in mTOR signaling, MPS, and hypertrophy following acute and chronic BFR exercise.

A Pilot Study of Women’s Affective Responses to Common and Uncommon Forms of Aerobic Exercise

PubMed Central

Stevens, Courtney J.; Smith, Jane Ellen; Bryan, Angela D.

2015-01-01

Objective To test the extent to which participants exposed to an uncommon versus common exercise stimulus would result in more favourable affect at post task. Design Experimental design. Participants, (N = 120) American women aged 18–45 years, were randomly assigned to complete 30-minutes of either the uncommon (HOOP; n = 58) or common (WALK; n = 62) exercise stimulus. Main Outcome Measures Self-reported affect and intentions for future exercise were measured before and after the 30-minute exercise bout. Results Analyses of covariance (ANCOVA) were run to compare post-task affect across the HOOP and WALK conditions. At post-task, participants assigned to HOOP reported more positively valenced affect, higher ratings of positive activated affect, lower ratings of negative deactivated affect, and stronger intentions for future aerobic exercise compared to participants assigned to WALK. Conclusions Participants who completed an uncommon bout of aerobic exercise (HOOP) reported more favourable affect post-exercise, as well as stronger intentions for future exercise, compared to participants who completed a common bout of aerobic exercise (WALK). Future work using a longitudinal design is needed to understand the relationships between familiarity with an exercise stimulus, affective responses to exercise, motivation for future exercise behaviour, and exercise maintenance over time. PMID:26394246

Blood pressure and plasma catecholamine responses to various challenges during exercise-recovery in man.

PubMed

Péronnet, F; Massicotte, D; Paquet, J E; Brisson, G; de Champlain, J

1989-01-01

The purpose of this study was to assess the effects of a 2 h cycle exercise (50% VO2max) on heart rate (HR) and blood pressure (BP), and on plasma epinephrine (E) and norepinephrine (NE) concentrations, during the recovery period in seven normotensive subjects. Measurements were made at rest in supine (20 min) and standing (10 min) positions, during isometric exercise (hand-grip, 3 min, 25% maximal voluntary, contraction), in response to a mild psychosocial challenge (Stroop conflicting color word task) and during a 5-min period of light exercise (42 +/- 3% VO2max). Data were compared to measurements taken on another occasion under similar experimental conditions, without a previous exercise bout (control). The results showed HR to be slightly elevated in all conditions following the exercise bout. However, diastolic and systolic BP during the recovery period following exercise were not significantly different from the values observed in the control situation. Plasma NE concentrations in supine position and in response to the various physiological and/or psychosocial challenges were similar in the control situation and during the recovery period following exercise. On the other hand plasma E (nmol.1-1) was about 50% lower at rest (0.11 +/- 0.03 vs 0.23 +/- 0.04) as well as in response to hand-grip (0.21 +/- 0.04 vs 0.41 +/- 0.20) and the Stroop-test (0.21 +/- 0.05 vs 0.41 +/- 0.15) following the exercise bout.(ABSTRACT TRUNCATED AT 250 WORDS)

Abnormal heart rate recovery and chronotropic incompetence on exercise in chronic obstructive pulmonary disease.

PubMed

Gupta, Mansi; Bansal, Vishal; Chhabra, Sunil K

2013-08-01

Chronotropic incompetence (CI; failure to reach the targeted heart rate (HR) on exercise) and a delayed HR recovery (HRR; ≤12 beats decline within the first minute after cessation) reflect autonomic dysfunction (AD) and predict adverse cardiac prognosis. As chronic obstructive pulmonary disease (COPD) is known to be associated with AD, we hypothesized that these patients may manifest these responses on exercise. The prevalence and predictors of these responses in COPD and their association with its severity have not been evaluated. Normoxemic, stable male patients with COPD (n = 39) and 11 healthy controls underwent lung function testing and incremental leg ergometry. HR responses were monitored during exercise and recovery to compute the HRR and CI. Of all the patients, 33 (84.6%) had at least one of the two exercise responses as abnormal, with the majority (23, 58.9%) having both an abnormal HRR and CI. The frequency of abnormal responses increased with increasing Global Initiative for Chronic Obstructive Lung Disease stage and body mass index, airflow obstruction, dyspnoea and exercise capacity index. After adjusting for smoking history and post-bronchodilator forced expiratory volume in 1 second, only a reduced diffusion capacity for carbon monoxide predicted abnormal HRR, though weakly. We concluded that abnormal HRR and CI are common in patients with COPD. These responses are observed with increasing frequency as the severity of disease increases.

Maximal exercise increases mucosal associated invariant T cell frequency and number in healthy young men.

PubMed

Hanson, Erik D; Danson, Eli; Nguyen-Robertson, Catriona V; Fyfe, Jackson J; Stepto, Nigel K; Bartlett, David B; Sakkal, Samy

2017-11-01

Mucosal associated invariant T (MAIT) cells have properties of the innate and acquired immune systems. While the response to vigorous exercise has been established for most leukocytes, MAIT cells have not been investigated. Therefore, the purpose was to determine if MAIT cell lymphocytosis occurs with acute maximal aerobic exercise and if this response is influenced by exercise duration, cardiovascular fitness, or body composition. Twenty healthy young males with moderate fitness levels performed an extended graded exercise test until volitional fatigue. Peripheral blood mononuclear cells were isolated from venous blood obtained prior and immediately after exercise and were labeled to identify specific T cell populations using flow cytometry. The percentage of MAIT cells relative to total T cells significantly increased from 3.0 to 3.8% and absolute MAIT cell counts increased by 2.2-fold following maximal exercise. MAIT cell subpopulation proportions were unchanged with exercise. Within cytotoxic T lymphocytes (CTL), MAIT cells consisted of 8% of these cells and this remained constant after exercise. MAIT cell counts and changes with exercise were not affected by body composition, VO 2peak , or exercise duration. Maximal exercise doubled MAIT cell numbers and showed preferential mobilization within total T cells but the response was not influenced by fitness levels, exercise duration, or body composition. These results suggest that acute exercise could be used to offset MAIT cell deficiencies observed with certain pathologies. MAIT cells also make up a substantial proportion of CTLs, which may have implications for cytotoxicity assays using these cells.

Validation of the Social Exercise and Anxiety Measure (SEAM): Assessing fears, avoidance, and importance of social exercise

PubMed Central

Levinson, Cheri A.; Rodebaugh, Thomas L.; Menatti, Andrew R.; Weeks, Justin W.

2012-01-01

In two studies (N = 416; N = 118) examining responses from undergraduates, we developed the Social Exercise and Anxiety Measure (SEAM) and tested its factorial, convergent, and divergent validity. Our results demonstrate that the SEAM exhibits an excellent three factor structure consisting of the following subscales: Social Exercise Self-efficacy, Gym Avoidance, and Exercise Importance. In both studies, Social Exercise Self-efficacy correlated negatively and Gym Avoidance correlated positively with social interaction anxiety, fear of scrutiny, and fear of negative evaluation. Exercise Importance correlated positively with frequency of exercise and frequency of public exercise. Implications for the mental and physical health of individuals with high levels of social anxiety are discussed. PMID:24244069

Effects of air ventilation during stationary exercise testing.

PubMed

Van Schuylenbergh, R; Vanden Eynde, B; Hespel, P

2004-07-01

The impact of air ventilation on performance and physiological responses during stationary exercise in the laboratory was studied. Fourteen well-trained cyclists performed three exercise tests on a cycle ergometer, each separated by a 1-week interval. The first test was a graded test to determine the power output corresponding with the 4-mmol l(-1) lactate level. Tests 2 and 3 were 30-min constant-load tests at a power output corresponding with this 4-mmol l(-1) lactate threshold. One constant-load test was performed in the absence (NAV), whilst the other was performed in the presence (AV) of air ventilation (3 m s(-1)). During the constant-load tests, heart rate, tympanic temperature, blood lactate concentration and oxygen uptake (VO2) were measured at 10-min intervals and at the end of the test. Differences between the two test conditions were evaluated using paired t-tests. During NAV, 12 subjects interrupted the test due to premature exhaustion (exercise duration <30 min), versus only seven in AV ( P<0.05). At the end of the test tympanic temperature was 35.9 (0.2) degrees C in AV and was higher in NAV [36.7 (0.2) degrees C, P<0.05]. Exercise heart rate increased at a faster rate during NAV [+2.2 (0.3) beats min(-1)] than during AV [+1.5 (0.2) beats min(-1), P<0.05]. Blood lactate concentration and VO2 were similar between conditions. Air ventilation is essential to prevent an upward shift in the lactate:heart rate as well as the power output:heart rate relationship during laboratory exercise testing and indoor exercise training.

Reliability of an incremental exercise test to evaluate acute blood lactate, heart rate and body temperature responses in Labrador retrievers.

PubMed

Ferasin, Luca; Marcora, Samuele

2009-10-01

Thirteen healthy Labrador retrievers underwent a 5-stage incremental treadmill exercise test to assess its reliability. Blood lactate (BL), heart rate (HR), and body temperature (BT) were measured at rest, after each stage of exercise, and after a 20-min recovery. Reproducibility was assessed by repeating the test after 7 days. Two-way MANOVAs revealed significant differences between consecutive stages, and between values at rest and after recovery. There was also a significant reduction in physiological strain between the first and second trial (learning effect). Test reliability expressed as typical error (BL = 0.22 mmol/l, HR = 9.81 bpm, BT = 0.22 degrees C), coefficient of variation (BL = 19.3%, HR = 7.9% and BT = 0.6%) and test-retest correlation (BL = 0.89, HR = 0.96, BT = 0.95) was good. Results support test reproducibility although the learning effect needs to be controlled when investigating the exercise-related problems commonly observed in this breed.

The planning, execution, and evaluation of a mass prophylaxis full-scale exercise in cook county, IL.

PubMed

Kilianski, Andy; O'Rourke, Amy T; Carlson, Crystal L; Parikh, Shannon M; Shipman-Amuwo, Frankie

2014-01-01

Increasing threats of bioterrorism and the emergence of novel disease agents, including the recent international outbreaks of H7N9 influenza and MERS-CoV, have stressed the importance and highlighted the need for public health preparedness at local, regional, and national levels. To test plans that were developed for mass prophylaxis scenarios, in April 2013 the Cook Country Department of Public Health (CCDPH) and the Triple Community (TripCom) Medical Reserve Corps (MRC) executed a full-scale mass prophylaxis exercise in response to a simulated anthrax bioterrorism attack. The exercise took place over 2 days and included the TripCom Point-of-Dispensing (POD) Management Team, volunteers from the TripCom MRC, and neighboring public health departments and MRCs. Individuals from the community volunteered as actors during the exercise, while local municipal, police, and fire personnel coordinated their responses to create the most realistic simulation possible. The exercise was designed to test the capacity of TripCom and CCDPH to implement plans for organizing municipal staff and volunteers to efficiently distribute prophylaxis to the community. Based on results from POD clinic flow, accuracy of prophylaxis distribution, and observations from evaluators, the exercise was successful in demonstrating areas that were operationally efficient as well as identifying areas that can be improved on. These include improvements to the just-in-time training for POD staff, the health screening and consent forms handed out to patients, the physical setup of the POD, and the command structure and communication for the management of POD operations. This article demonstrates the need for full-scale exercises and identifies gaps in POD planning that can be integrated into future plans, exercises, and emergency response.

Effect of In-Flight Exercise and Extravehicular Activity on Postflight Stand Tests

NASA Technical Reports Server (NTRS)

Lee, Stuart M. C.; Moore, Alan D., Jr.; Fritsch-Yelle, Janice; Greenisen, Michael; Schneider, Suzanne M.; Foster, Philip P.

2000-01-01

The purpose of this study was to determine whether exercise performed by Space Shuttle crewmembers during short-duration spaceflights (9-16 days) affects the heart rate (HR) and blood pressure (BP) responses to standing within 2-4 hr of landing. Thirty crewmembers performed self-selected in-flight exercise and maintained exercise logs to monitor their exercise intensity and duration. A 10min stand test, preceded by at least 6 min of quiet supine rest, was completed 10- 15 d before launch (PRE) and within four hours of landing (POST). Based upon their in-flight exercise records, subjects were grouped as either high (HIex: = 3x/week, HR = 70% ,HRMax, = 20 min/session, n = 11), medium (MEDex: = 3x/week, HR = 70% HRmax, = 20 min/session, n = 10), or low (LOex: = 3x/week, HR and duration variable, n = 11) exercisers. HR and BP responses to standing were compared between groups (ANOVA, or analysis of variance, P < 0.05). There were no PRE differences between the groups in supine or standing HR and BP. Although POST supine HR was similar to PRE, all groups had an increased standing HR compared to PRE. The increase in HR upon standing was significantly greater after flight in the LOex group (36+/-5 bpm) compared to HIex or MEDex groups (25+/-1bpm; 22+/-2 bpm). Similarly, the decrease in pulse pressure (PP) from supine to standing was unchanged after spaceflight in the MEDex and HIex groups, but was significantly less in the LOex group (PRE: -9+/- 3, POST: -19+/- 4 mmHg). Thus, moderate to high levels of in-flight exercise attenuated HR and PP responses to standing after spaceflight compared.

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.

Oxygen uptake during peak graded exercise and single-stage fatigue tests of wheelchair propulsion in manual wheelchair users and the able-bodied.

PubMed

Keyser, R E; Rodgers, M M; Gardner, E R; Russell, P J

1999-10-01

To determine if a single-stage, submaximal fatigue test on a wheelchair ergometer would result in higher than expected energy expenditure. An experimental survey design contrasting physiologic responses during peak graded exercise tests and fatigue tests. A rehabilitation science laboratory that included a prototypical wheelchair ergometer, open-circuit spirometry system, and heart rate monitor. Nine able-bodied non-wheelchair users (the NWC group: 6 men and 3 women, mean +/- SD age 30 +/- 7yrs) and 15 manual wheelchair users (the WC group: 12 men and 3 women, age 40 +/- 9yrs, time in wheelchair 16 +/- 9yrs). No subject had any disease, medication regimen, or upper body neurologic, orthopedic, or other condition that would limit wheelchair exercise. Peak oxygen uptake (VO2) for graded exercise testing and during fatigue testing, using a power output corresponding to 75% peak aerobic capacity on graded exercise test. In the WC group, VO2 at 6 minutes of fatigue testing was not significantly different from peak VO2. In the NWC group, VO2 was similar to the expected level throughout fatigue testing. Energy expenditure was higher than expected in the WC group but not in the NWC group. Fatigue testing may provide a useful evaluation of cardiorespiratory status in manual wheelchair users.

Lack of endogenous pain inhibition during exercise in people with chronic whiplash associated disorders: an experimental study.

PubMed

Van Oosterwijck, Jessica; Nijs, Jo; Meeus, Mira; Van Loo, Michel; Paul, Lorna

2012-03-01

A controlled experimental study was performed to examine the efficacy of the endogenous pain inhibitory systems and whether this (mal)functioning is associated with symptom increases following exercise in patients with chronic whiplash-associated disorders (WAD). In addition, 2 types of exercise were compared. Twenty-two women with chronic WAD and 22 healthy controls performed a submaximal and a self-paced, physiologically limited exercise test on a cycle ergometer with cardiorespiratory monitoring on 2 separate occasions. Pain pressure thresholds (PPT), health status, and activity levels were assessed in response to the 2 exercise bouts. In chronic WAD, PPT decreased following submaximal exercise, whereas they increased in healthy subjects. The same effect was established in response to the self-paced, physiologically limited exercise, with exception of the PPT at the calf which increased. A worsening of the chronic WAD symptom complex was reported post-exercise. Fewer symptoms were reported in response to the self-paced, physiologically limited exercise. These observations suggest abnormal central pain processing during exercise in patients with chronic WAD. Submaximal exercise triggers post-exertional malaise, while a self-paced and physiologically limited exercise will trigger less severe symptoms, and therefore seems more appropriate for chronic WAD patients. The results from this exercise study suggest impaired endogenous pain inhibition during exercise in people with chronic WAD. This finding highlights the fact that one should be cautious when evaluating and recommending exercise in people with chronic WAD, and that the use of more individual, targeted exercise therapies is recommended. Copyright © 2012 American Pain Society. Published by Elsevier Inc. All rights reserved.

Radiological/Nuclear Human Monitoring Tabletop Exercise: Recommendations and Lessons Identified.

PubMed

Chauhan, Vinita; Duncan, Devin; Wilkins, Ruth C

2017-06-01

Health Canada is the lead department for coordinating the federal response to a Canadian nuclear emergency event. The framework to manage a radiological consequence is outlined in the Federal Nuclear Emergency Plan (FNEP). In 2014, a full scale exercise (FSX) was held to test the capacity of the federal government to handle a nuclear facility emergency disaster in Canada. The FSX provided a means to demonstrate the integration of various departments and agencies in response to such an event, and although a number of task teams within FNEP were tested, the capacity to monitor humans for exposure post-event was not played out fully. To address this, a table top exercise (TTX) was held in 2015 that brought together experts from human monitoring groups (HMGs) in partnership with Provincial and Municipal emergency response organizations. The TTX took the form of a facilitated discussion centered around two types of radiological/nuclear (RN) emergency scenarios that commenced post-release. The purpose of the exercise was to integrate these communities and identify knowledge gaps in policies and concepts of operations pertaining to the human monitoring aspects of RN events including biodosimetry, bioassay, portal monitors, whole body counting, and the provision of personal dosimetry. It also tested the interoperability between first responders/receivers and Federal, Provincial, and Municipal emergency response organizations. The end outcome was the identification of clear knowledge gaps in existing and newly developed concepts of operation in the human population monitoring response to an RN emergency in Canada; these and possible recommendations are captured in this report.

Rosiglitazone lowers resting and blood pressure response to exercise in men with type 2 diabetes: A 1-year randomized study.

PubMed

Piché, Marie-Eve; Laberge, Anne-Sophie; Brassard, Patrice; Arsenault, Benoit J; Bertrand, Olivier F; Després, Jean-Pierre; Costerousse, Olivier; Poirier, Paul

2018-07-01

We aimed to determine the effect of 1-year treatment with the insulin sensitizer peroxisome proliferator-activated receptor (PPAR)-γ agonist rosiglitazone on exercise capacity and blood pressure (BP) response to exercise in men with coronary artery disease (CAD) and type 2 diabetes (T2D). A total of 116 men (age, 64 ± 7 years; body mass index, 30.0 ± 4.4 kg/m 2 ) with CAD and T2D were randomized to receive rosiglitazone or placebo for 1 year. Exercise capacity (VO 2peak ) and BP response to exercise were assessed with a maximal treadmill test, prior to the intervention and at 1-year follow-up. Exercise-induced hypertension (EIH) was defined as maximal systolic BP ≥ 220 mm Hg and/or diastolic BP ≥ 100 mm Hg. PPAR-γ agonist-treated patients showed improvements in fasting glucose, HbA1c and insulin sensitivity (Homeostasis model assessment of insulin resistance [HOMA-IR]) (all P < .05). Resting BPs, maximal exercise diastolic BP and resting rate-pressure product (RPP) were all reduced in the PPAR-γ agonist group (P < .05). Maximal exercise duration was unchanged. T2D patients who displayed the greatest improvement in insulin sensitivity (HOMA-IR) under PPAR-γ agonist treatment experienced a greater reduction in exercise BP and RPP (P < .05). The proportion of men with EIH decreased in the PPAR-γ agonist group during follow-up (39.00% ± 0.06% vs 21.00% ± 0.05%). In the subgroup with EIH that was treated with a PPAR-γ agonist, resting and exercise diastolic BP, as well as resting RPP, were all reduced at 1-year follow-up (P < .05). The insulin sensitizer rosiglitazone has a beneficial effect on resting and BP response to exercise in men with CAD and T2D, especially in those with an exaggerated BP response to exercise. © 2018 John Wiley & Sons Ltd.

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

PubMed Central

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

2015-01-01

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

Specificity Elicits Higher Maximal and Submaximal Cardiorespiratory Responses During a New Taekwondo Aerobic Test.

PubMed

Hausen, Matheus; Soares, Pedro Paulo; Araujo, Marcus Paulo; Esteves, Débora; Julio, Hilbert; Tauil, Roberto; Junca, Marcus; Porto, Flávia; Franchini, Emerson; Bridge, Craig Alan; Gurgel, Jonas

2018-05-10

The purpose of the present study was to propose and validate new taekwondo-specific cardiopulmonary exercise tests. Twelve male national-level taekwondo athletes (age 20 ± 2 yrs; body mass 67.5 ± 5.7 kg; height 175 ± 8 cm; training experience 7 ± 3 yrs) performed three separate exercise tests in a randomized counterbalanced order: 1) a Treadmill Running Cardiopulmonary Exercise Test (CPET); 2) Continuous and 3) Interval Taekwondo Cardiopulmonary Exercise Tests (cTKDet and iTKDet, respectively). The CPET was administered using an individualized ramp protocol. Taekwondo tests comprised sequences of turning kicks performed upon a stationary target. The impacts were recorded via an electronic scoring sensor used in official competition. Stages on the cTKDet and iTKDet lasted 1-min and progressively reduced the kick interval duration. These were guided by a sound signal, starting with 4.6s between kicks and reducing by 0.4s every minute until the test ended. Oxygen uptake (V̇O 2 ), heart rate (HR), capillary blood lactate and ratings of perceived exertion were measured. Modest differences were identified in V̇O 2MAX between the tests (F 2,22 =3.54; p=0.046; ES=0.16). HR MAX was higher during both taekwondo tests (F 2,22 =14.3; p=0.001; ES=1.14) compared with CPET. Specific tests also yielded higher responses in the 1 st ventilatory threshold V̇O 2 (F 2,22 =6.5; p=0.04; ES=0.27) and HR (F 2,22 =12.3; p<0.001; ES=1.06), and HR at the 2 nd ventilatory threshold (F 2,22 =5.7; p=0.02; ES=0.72). Taekwondo-specific cardiopulmonary tests enhance the validity of some cardiopulmonary responses, and might therefore be considered to optimise routine diagnostic testing and training prescription for this athletic group.

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.

Computer model of cardiovascular control system responses to exercise

NASA Technical Reports Server (NTRS)

Croston, R. C.; Rummel, J. A.; Kay, F. J.

1973-01-01

Approaches of systems analysis and mathematical modeling together with computer simulation techniques are applied to the cardiovascular system in order to simulate dynamic responses of the system to a range of exercise work loads. A block diagram of the circulatory model is presented, taking into account arterial segments, venous segments, arterio-venous circulation branches, and the heart. A cardiovascular control system model is also discussed together with model test results.

Planning and preparing for public health threats at airports.

PubMed

Martin, Greg; Boland, Mairin

2018-03-07

The ever-increasing speed and scope of human mobility by international air travel has led to a global transport network for infectious diseases with the potential to introduce pathogens into non-endemic areas, and to facilitate rapid spread of novel or mutated zoonotic agents.Robust national emergency preparedness is vital to mitigate the transmission of infectious diseases agents domestically and to prevent onward spread to other countries. Given the complex range of stakeholders who respond to an infectious disease threat being transmitted through air travel, it is important that protocols be tested and practised extensively in advance of a real emergency. Simulation exercises include the identification of possible scenarios based on the probability of hazards and the vulnerability of populations as a basis for planning, and provide a useful measure of preparedness efforts and capabilities.In October 2016, a live simulation exercise was conducted at a major airport in Ireland incorporating a public health threat for the first time, with the notification of a possible case of MERS-CoV aboard an aircraft plus an undercarriage fire. Strengths of the response to the communicable disease threat included appropriate public health risk assessment, case management, passenger information gathering, notification to relevant parties, and communication to passengers and multiple agencies.Lessons learned include:o Exercise planning should not be overly ambitious. In testing too many facets of emergency response, the public health response could be deprioritised.o The practical implementation of communication protocols in a real-time exercise of this scope proved challenging. These protocols should continue to be checked and tested by desk-top exercises to ensure that all staff concerned are familiar with them, especially in the context of staff turn-over.o The roles and responsibilities of the various agencies must be clear to avoid role confusion.o Equipment and infrastructure capacities must be considered and in place in advance of an actual incident or test, for example whether or not cell phone signals require boosting during a major event.Importantly, exercises bring together individuals representing organisations with different roles and perspectives allowing identification of capabilities and limitations, and problem solving about how to address the gaps and overlaps in a low-threat collaborative setting.

Effects of heat acclimation on time perception.

PubMed

Tamm, Maria; Jakobson, Ainika; Havik, Merle; Timpmann, Saima; Burk, Andres; Ööpik, Vahur; Allik, Jüri; Kreegipuu, Kairi

2015-03-01

Cognitive performance is impaired during prolonged exercise in hot environment compared to temperate conditions. These effects are related to both peripheral markers of heats stress and alterations in CNS functioning. Repeated-exposure to heat stress results in physiological adaptations, and therefore improvement in exercise capacity and cognitive functioning are observed. The objective of the current study was to clarify the factors contributing to time perception under heat stress and examine the effect of heat acclimation. 20 young healthy male subjects completed three exercise tests on a treadmill: H1 (at 60% VO(2)peak until exhaustion at 42°C), N (at 22°C; duration equal to H1) and H2 (walk until exhaustion at 42°C) following a 10-day heat acclimation program. Core temperature (T(C)) and heart rate (HR), ratings of perceived fatigue and exertion were obtained continuously during the exercise, and blood samples of hormones were taken before, during and after the exercise test for estimating the prolactin, growth hormone and cortisol response to acute exercise-heat stress. Interval production task was performed before, during and after the exercise test. Lower rate of rise in core temperature, heart rate, hormone response and subjective ratings indicated that the subjects had successfully acclimated. Before heat acclimation, significant distortions in produced intervals occurred after 60 minutes of exercise relative to pre-trial coefficients, indicating speeded temporal processing. However, this effect was absent after in acclimated subjects. Blood prolactin concentration predicted temporal performance in both conditions. Heat acclimation slows down the increase in physiological measures, and improvement in temporal processing is also evident. The results are explained within the internal clock model in terms of the pacemaker-accumulator functioning. Copyright © 2014 Elsevier B.V. All rights reserved.

Association between angiotensin-converting enzyme gene polymorphisms and exercise performance in patients with COPD.

PubMed

Zhang, Xiaolei; Wang, Chen; Dai, Huaping; Lin, Yingxiang; Zhang, Jun

2008-09-01

Recent studies have shown that polymorphisms of the angiotensin-converting enzyme (ACE) gene are closely associated with pulmonary disorders. The ACE gene is involved in the regulation of inflammatory reactions to lung injury, respiratory drive, erythropoiesis and tissue oxygenation. The hypothesis for this study was that the ACE gene may be associated with the ventilatory response to exercise and the aerobic work efficiency of skeletal muscle in patients with COPD. Sixty-one Chinese Han COPD patients and 57 healthy control subjects performed incremental cardiopulmonary exercise testing on a cycle ergometer. ACE genotypes were determined using PCR amplification. Resting lung function and blood gas index were not significantly different among the three ACE genotype COPD groups. Similarly, there were no significant differences in AT, maximal O(2) uptake, maximal O(2) pulse, maximal dyspnoea index, ventilatory response (DeltaVE/DeltaVCO(2)), O(2) cost of ventilation (VO(2)/W/VE), end-tidal partial pressure of carbon dioxide at maximal exercise and maximal SaO(2) among the three ACE genotype COPD patients. Maximal work load and aerobic work efficiency were higher in the COPD group with the II genotype than in those with the ID or DD genotype. There were no significant differences in resting lung function and cardiopulmonary exercise testing parameters among the three ACE genotype control groups. The ACE gene may be involved in the regulation of skeletal muscle aerobic work efficiency, but is not associated with the ventilatory responses to exercise in COPD patients.

The Relation of Arm Exercise Peak Heart Rate to Stress Test Results and Outcome.

PubMed

Xian, Hong; Liu, Weijian; Marshall, Cynthia; Chandiramani, Pooja; Bainter, Emily; Martin, Wade H

2016-09-01

Arm exercise is an alternative to pharmacologic stress testing for >50% of patients unable to perform treadmill exercise, but no data exist regarding the effect of attained peak arm exercise heart rate on test sensitivity. Thus, the purpose of this investigation was to characterize the relationship of peak arm exercise heart rate responses to abnormal stress test findings, coronary revascularization, and mortality in patients unable to perform leg exercise. From 1997 until 2002, arm cycle ergometer stress tests were performed in 443 consecutive veterans age 64.1 yr (11.0 yr) (mean (SD)), of whom 253 also underwent myocardial perfusion imaging (MPI). Patients were categorized by frequency distributions of quartiles of percentage age-predicted peak heart rate (APPHR), heart rate reserve (HRR), and peak heart rate-systolic blood pressure product (PRPP). Exercise-induced ST-segment depression, abnormal MPI findings, coronary revascularization, and 12.0-yr (1.3 yr) Kaplan-Meier all-cause and cardiovascular mortality plots were then characterized by quartiles of APPHR, HRR, and PRPP. A reduced frequency of abnormal arm exercise ECG results was associated only with the lowest quartile of APPHR (≤69%) and HRR (≤43%), whereas higher frequency of abnormal MPI findings exhibited an inverse relationship trend with lower APPHR (P = 0.10) and HRR (P = 0.12). There was a strong inverse association of APPHR, HRR, and PRPP with all-cause (all P ≤ 0.01) and cardiovascular (P < 0.05) mortality. The frequency of coronary revascularization was unrelated to APPHR or HRR. Arm exercise ECG stress test sensitivity is only reduced at ≤69% APPHR or ≤43% HRR, whereas arm exercise MPI sensitivity and referral for coronary revascularization after arm exercise stress testing are not adversely affected by even a severely blunted peak heart rate. However, both all-cause mortality and cardiovascular mortality are strongly and inversely related to APPHR and HRR.

Dose-Response Effects of Exercise Duration and Recovery on Cognitive Functioning.

PubMed

Crush, Elizabeth A; Loprinzi, Paul D

2017-12-01

We examined the effects of different acute exercise durations and recovery periods on cognitive function in a counterbalanced, cross-over randomized controlled experiment. We placed 352 participants, aged 18 to 35 years into one of 16 experimental groups. Each participant visited the laboratory twice, separated by a 1-week washout period. Either Visit 1 or 2 consisted of an acute bout of moderate-intensity treadmill exercise (10, 20, 30, 45, or 60 minutes) followed by a period of rest (5, 15, or 30 minutes) before taking a set of five cognitive tests; the other visit consisted only of completing the cognitive tests (no exercise). Cognitive tests sampled multiple cognitive parameters, including reasoning, concentration, memory, attention, and planning. We found that a short recovery period (i.e., 5 minutes) may have a less favorable effect on planning ability but may be beneficial for memory. In addition, for various exercise durations and recovery periods, a Group × Time × Resting (nonexercise) A cognitive interaction effect was observed such that for both memory and inhibitory cognitive ability, acute exercise (vs. no exercise) had an enhancement effect for those with lower resting cognitive functioning. The length of the acute exercise recovery period and resting cognitive ability most influenced the association between exercise and cognitive function.

Plasma renin activity, aldosterone and catecholamine levels when swimming and running.

PubMed

Guezennec, C Y; Defer, G; Cazorla, G; Sabathier, C; Lhoste, F

1986-01-01

The purpose of this study was to determine the response of plasma renin activity (PRA), plasma aldosterone concentration (PAC) and catecholamines to two graded exercises differing by posture. Seven male subjects (19-25 years) performed successively a running rest on a treadmill and a swimming test in a 50-m swimming pool. Each exercise was increased in severity in 5-min steps with intervals of 1 min. Oxygen consumption, heart rate and blood lactate, measured every 5 min, showed a similar progression in energy expenditure until exhaustion, but there was a shorter time to exhaustion in the last step of the running test. PRA, PAC and catecholamines were increased after both types of exercise. The PRA increase was higher after the running test (20.9 ng AngI X ml-1 X h-1) than after swimming (8.66 ng AngI X ml-1 X h-1). The PAC increase was slightly greater after running (123 pg X ml-1) than swimming (102 pg X ml-1), buth the difference was not significant. Plasma catecholamine was higher after the swimming test. These results suggest that the volume shift induced by the supine position and water pressure during swimming decreased the PRA response. The association after swimming compared to running of a decreased PRA and an enhanced catecholamine response rule out a strict dependence of renin release under the effect of plasma catecholamines and is evidence of the major role of neural pathways for renin secretion during physical exercise.

Control Group Paradigms in Studies Investigating Acute Effects of Exercise on Cognitive Performance-An Experiment on Expectation-Driven Placebo Effects.

PubMed

Oberste, Max; Hartig, Philipp; Bloch, Wilhelm; Elsner, Benjamin; Predel, Hans-Georg; Ernst, Bernhard; Zimmer, Philipp

2017-01-01

Introduction: Many studies report improvements in cognitive performance following acute endurance exercise compared to control group treatment. These cognitive benefits are interpreted as a result of a physiological response to exercise. However, it was also hypothesized that expectation-driven placebo effects account for these positive effects. The purpose of this study was to investigate the differences between expectations for cognitive benefits toward acute endurance exercise and multiple control group treatments. Methods: Healthy individuals ( N = 247, 24.26 ± 3.88 years) were randomized to eight different groups watching videos of a moderate, a vigorous exercise treatment or one control group treatment (waiting, reading, video-watching, stretching, myofascial release workout, and very light exercise). Then, they were introduced to three commonly used cognitive test procedures in acute exercise-cognition research (Stroop-test, Trail-Making-test, Free-recall-task). Participants rated the effect they would expect on their performance in those tasks, if they had received the treatment shortly before the task, on an 11-point Likert scale. Results: No significantly different expectations for cognitive benefits toward acute moderate exercise and control group treatments could be revealed. Participants expected significantly worse performance following vigorous exercise compared to following waiting and stretching for all cognitive tests. Significantly worse performance after vigorous exercise compared to after very light exercise was expected for Stroop and Free-recall. For Free-recall, participants expected worse performance after vigorous exercise compared to myofascial release training as well. Conclusion: Our results indicate that expectation-driven placebo effects are unlikely to cause the reported greater cognitive improvements following acute moderate and vigorous endurance exercise compared to following common control group treatments.

Control Group Paradigms in Studies Investigating Acute Effects of Exercise on Cognitive Performance–An Experiment on Expectation-Driven Placebo Effects

PubMed Central

Oberste, Max; Hartig, Philipp; Bloch, Wilhelm; Elsner, Benjamin; Predel, Hans-Georg; Ernst, Bernhard; Zimmer, Philipp

2017-01-01

Introduction: Many studies report improvements in cognitive performance following acute endurance exercise compared to control group treatment. These cognitive benefits are interpreted as a result of a physiological response to exercise. However, it was also hypothesized that expectation-driven placebo effects account for these positive effects. The purpose of this study was to investigate the differences between expectations for cognitive benefits toward acute endurance exercise and multiple control group treatments. Methods: Healthy individuals (N = 247, 24.26 ± 3.88 years) were randomized to eight different groups watching videos of a moderate, a vigorous exercise treatment or one control group treatment (waiting, reading, video-watching, stretching, myofascial release workout, and very light exercise). Then, they were introduced to three commonly used cognitive test procedures in acute exercise-cognition research (Stroop-test, Trail-Making-test, Free-recall-task). Participants rated the effect they would expect on their performance in those tasks, if they had received the treatment shortly before the task, on an 11-point Likert scale. Results: No significantly different expectations for cognitive benefits toward acute moderate exercise and control group treatments could be revealed. Participants expected significantly worse performance following vigorous exercise compared to following waiting and stretching for all cognitive tests. Significantly worse performance after vigorous exercise compared to after very light exercise was expected for Stroop and Free-recall. For Free-recall, participants expected worse performance after vigorous exercise compared to myofascial release training as well. Conclusion: Our results indicate that expectation-driven placebo effects are unlikely to cause the reported greater cognitive improvements following acute moderate and vigorous endurance exercise compared to following common control group treatments. PMID:29276483

Importance of heart rate during exercise for response to cardiac resynchronization therapy.

PubMed

Maass, Alexander H; Buck, Sandra; Nieuwland, Wybe; Brügemann, Johan; van Veldhuisen, Dirk J; Van Gelder, Isabelle C

2009-07-01

Cardiac resynchronization therapy (CRT) is an established therapy for patients with severe heart failure and mechanical dyssynchrony. Response is only achieved in 60-70% of patients. To study exercise-related factors predicting response to CRT. We retrospectively examined consecutive patients in whom a CRT device was implanted. All underwent cardiopulmonary exercise testing prior to implantation and after 6 months. The occurrence of chronotropic incompetence and heart rates exceeding the upper rate of the device, thereby compromising biventricular stimulation, was studied. Response was defined as a decrease in LVESV of 10% or more after 6 months. We included 144 patients. After 6 months 86 (60%) patients were responders. Peak VO2 significantly increased in responders. Chronotropic incompetence was more frequently seen in nonresponders (21 [36%] vs 9 [10%], P = 0.03), mostly in patients in SR. At moderate exercise, defined as 25% of the maximal exercise tolerance, that is, comparable to daily life exercise, nonresponders more frequently went above the upper rate of the device (13 [22%] vs 2 [3%], P < 0.0001), most of whom were patients in permanent AF. Multivariate analysis revealed heart rates not exceeding the upper rate of the device during moderate exercise (OR 15.8 [3.3-76.5], P = 0.001) and nonischemic cardiomyopathy (OR 2.4 [1.0-5.7], P = 0.04) as predictive for response. Heart rate exceeding the upper rate during moderate exercise is an independent predictor for nonresponse to CRT in patients with AF, whereas chronotropic incompetence is a predictor for patients in SR.

Exercise training and weight loss, not always a happy marriage: single blind exercise trials in females with diverse BMI.

PubMed

Jackson, Matthew; Fatahi, Fardin; Alabduljader, Kholoud; Jelleyman, Charlotte; Moore, Jonathan P; Kubis, Hans-Peter

2018-04-01

Individuals show high variability in body weight responses to exercise training. Expectations and motivation towards effects of exercise on body weight might influence eating behaviour and could conceal regulatory mechanisms. We conducted 2 single-blind exercise trials (4 weeks (study 1) and 8 weeks (study 2)) with concealed objectives and exclusion of individuals with weight loss intention. Circuit exercise training programs (3 times a week (45-90 min), intensity 50%-90% peak oxygen uptake for 4 and 8 weeks) were conducted. Thirty-four females finished the 4-week intervention and 36 females the 8-week intervention. Overweight/obese (OV/OB) and lean female participants' weight/body composition responses were assessed and fasting and postprandial appetite hormone levels (PYY, insulin, amylin, leptin, ghrelin) were measured before and after the intervention for understanding potential contribution to individuals' body weight response to exercise training (study 2). Exercise training in both studies did not lead to a significant reduction of weight/body mass index (BMI) in the participants' groups; however, lean participants gained muscle mass. Appetite hormones levels were significantly (p < 0.05) altered in the OV/OB group, affecting fasting (-24%) and postprandial amylin (-14%) levels. Investigation of individuals' BMI responses using multiple regression analysis revealed that levels of fasting leptin, postprandial amylin increase, and BMI were significant predictors of BMI change, explaining about 43% of the variance. In conclusion, tested exercise training did not lead to weight loss in female participants, while a considerable proportion of variance in body weight response to training could be explained by individuals' appetite hormone levels and BMI.

Relationships of the systolic blood pressure response during exercise with insulin resistance, obesity, and endurance fitness in men with type 2 diabetes mellitus.

PubMed

Kumagai, S; Kai, Y; Hanada, H; Uezono, K; Sasaki, H

2002-10-01

The purpose of the present study was to investigate the relationships among the resting systolic (SBP) and diastolic blood pressure (DBP) or SBP response during exercise with insulin resistance evaluated by a homeostasis model (HOMA-IR), abdominal fat accumulation (visceral fat area [VFA], subcutaneous fat area [SFA]) by computed tomography (CT), and an estimation of the maximal oxygen uptake (V*O2max) in 63 Japanese middle-aged male patients with type 2 diabetes mellitus (type 2 DM). Body mass index (BMI) and waist-to-hip ratio (WHR) in type 2 DM subjects were significantly higher than in age-matched healthy male control subjects (n = 135) with normal glucose tolerance. Resting SBP (127.7 +/- 16.2 mm Hg v 119.4 +/- 13.0 mm Hg) and DBP (82.2 +/- 11.9mmHg v 76.8 +/- 9.4 mm Hg) levels, and the percentage of hypertension (20.6% v 1.5%) in type 2 DM subjects were significantly higher than in the control subjects (P <.05). According to a multiple regression analysis for resting blood pressure in type 2 DM, VFA was found to be an independent predictor of SBP, while V*O2max and HOMA-IR were independent predictors of DBP. In the controls, however, HOMA-IR was not found to be a significantly independent predictor for either resting SBP or resting DBP. Measurement of the SBP response during graded exercise using a ramp test was performed by an electrical braked cycle ergometer in 54 patients with type 2 DM only. The SBP was measured at 15-second intervals during exercise. The exercise intensity at the double product breaking point (DPBP), which strongly correlated with the exercise intensity at the lactate threshold, was used as an index for the SBP response to standardized exercise intensity. The SBP corresponding to exercise intensity at DPBP (SBP@DPBP) was evaluated as an index of the SBP response to standardized exercise intensity. The change in SBP (deltaSBP = SBP@DPBP - resting SBP) was significantly and positively associated with log area under the curve for glucose (log AUCPG) during a 75-g oral glucose tolerance test (OGTT). In addition, deltaSBP significantly and negatively correlated with the log area under the curve for insulin (log AUCIRI) and log AUCIRI/log AUCPG. Based on these results, insulin resistance was suggested to be independently associated with the resting DBP and SBP response to standardized exercise intensity in type 2 DM patients. Copyright 2002, Elsevier Science (USA). All rights reserved.

U.S. Coast Guard SARSAT Final Evaluation Report. Volume II. Appendices.

DOT National Transportation Integrated Search

1987-03-01

Contents: Controlled Tests; Controlled Test Error Analysis, Processing of Westwind Data; Exercises and Homing Tests; Further Analysis of Controlled Tests; Sar Case Analysis Tables; Narratives of Real Distress Cases; RCC Response Scenarios; Workload A...

Correlation of exercise response in repaired coarctation of the aorta to left ventricular mass and geometry.

PubMed

Krieger, Eric V; Clair, Mathieu; Opotowsky, Alexander R; Landzberg, Michael J; Rhodes, Jonathan; Powell, Andrew J; Colan, Steven D; Valente, Anne Marie

2013-02-01

The role of exercise testing to risk stratify patients with repaired coarctation of the aorta (CoA) is controversial. Concentric left ventricular (LV) hypertrophy, defined as an increase in the LV mass-to-volume ratio (MVR), is associated with a greater incidence of adverse cardiovascular events. The objective of the present study was to determine whether a hypertensive response to exercise (HRE) is associated with increased LVMVR in patients with repaired CoA. Adults with repaired CoA who had a symptom-limited exercise test and cardiac magnetic resonance imaging examination within 2 years were identified. A hypertensive response to exercise was defined as a peak systolic blood pressure >220 mm Hg during a symptom-limited exercise test. The LV mass and volume were measured using cardiac magnetic resonance by an investigator who was unaware of patient status. We included 47 patients (median age 27.3 years, interquartile range 19.8 to 37.3), who had undergone CoA repair at a median age of 4.6 years (interquartile range 0.4 to 15.7). Those with (n = 11) and without (n = 36) HRE did not differ in age, age at repair, body surface area, arm-to-leg systolic blood pressure gradient, gender, or peak oxygen uptake with exercise. Those with a HRE had a greater mean systolic blood pressure at rest (146 ± 18 vs 137 ± 18 mm Hg, p = 0.04) and greater median LVMVR (0.85, interquartile range 0.7 to 1, vs 0.66, interquartile range 0.6 to 0.7; p = 0.04) than those without HRE. Adjusting for systolic blood pressure at rest, age, age at repair, and gender, the relation between HRE and LVMVR remained significant (p = 0.001). In conclusion, HRE was associated with increased LVMVR, even after adjusting for multiple covariates. Copyright © 2013 Elsevier Inc. All rights reserved.

Exercise capacity in young adults with hypertension and systolic blood pressure difference between right arm and leg after repair of coarctation of the aorta.

PubMed

Instebø, Arne; Norgård, Gunnar; Helgheim, Vegard; Røksund, Ola Drange; Segadal, Leidulf; Greve, Gottfried

2004-10-01

Coarctation of the aorta represents 5-7% of congenital heart defects. Symptoms and prognosis depend on the degree of stenosis, age at surgery, surgical method and the presence of other heart defects. Postoperative complications are hypertension, restenosis and an abnormal blood pressure response during exercise. This study includes 41 patients, 15-40 years old, operated in the period 1975-1996. All were exercised on a treadmill until maximal oxygen consumption was achieved. Blood pressure was measured in the right arm and leg before and immediately after exercise, and in the right arm during exercise. Oxygen consumption was monitored and we defined an aerobic phase, an isocapnic buffering phase and a hypocapnic hyperventilation phase. The resting systolic blood pressure correlates with the resting systolic blood pressure difference between right arm and leg. A resting systolic blood pressure difference between the right arm and leg of 0.13 kPa (1 mmHg) to 2.67 kPa (20 mmHg) corresponds with a slight increase in resting systolic blood pressure. This rise in blood pressure increases the aerobic phase of the exercise test, helping the patients to achieve higher maximal oxygen consumption. A resting systolic blood pressure difference of more than 2.67 kPa (20 mmHg) corresponds with severe hypertension and causes reduction in the aerobic phase and maximal oxygen consumption. Resting systolic blood pressure and resting systolic blood pressure difference between the right arm and leg are not indicators for blood pressure response during exercise. Exercise testing is important to reveal exercise-induced hypertension and to monitor changes in transition from aerobic to anaerobic exercise and limitation to exercise capacity.

Effect of exercise training on ventilatory efficiency in patients with heart disease: a review.

PubMed

Prado, D M L; Rocco, E A; Silva, A G; Rocco, D F; Pacheco, M T; Furlan, V

2016-06-20

The analysis of ventilatory efficiency in cardiopulmonary exercise testing has proven useful for assessing the presence and severity of cardiorespiratory diseases. During exercise, efficient pulmonary gas exchange is characterized by uniform matching of lung ventilation with perfusion. By contrast, mismatching is marked by inefficient pulmonary gas exchange, requiring increased ventilation for a given CO2 production. The etiology of increased and inefficient ventilatory response to exercise in heart disease is multifactorial, involving both peripheral and central mechanisms. Exercise training has been recommended as non-pharmacological treatment for patients with different chronic cardiopulmonary diseases. In this respect, previous studies have reported improvements in ventilatory efficiency after aerobic exercise training in patients with heart disease. Against this background, the primary objective of the present review was to discuss the pathophysiological mechanisms involved in abnormal ventilatory response to exercise, with an emphasis on both patients with heart failure syndrome and coronary artery disease. Secondly, special focus was dedicated to the role of aerobic exercise training in improving indices of ventilatory efficiency among these patients, as well as to the underlying mechanisms involved.

Stress reactivity to and recovery from a standardised exercise bout: a study of 31 runners practising relaxation techniques.

PubMed

Solberg, E E; Ingjer, F; Holen, A; Sundgot-Borgen, J; Nilsson, S; Holme, I

2000-08-01

To compare the efficacy in runners of two relaxation techniques with regard to exercise reactivity and recovery after exercise. Thirty one adult male runners were studied prospectively for six months in three groups practising either meditation (n = 11) or autogenic training (n = 11) or serving as controls (n = 10). Before and after the six months relaxation intervention, indicators of reactivity to exercise and metabolism after exercise (blood lactate concentration, heart rate (HR), and oxygen consumption (VO2)), were tested immediately after and 10 minutes after exercise. Resting HR was also assessed weekly at home during the trial. State anxiety was measured before and after the intervention. After the relaxation training, blood lactate concentration after exercise was significantly (p<0.01) decreased in the meditation group compared with the control group. No difference was observed in lactate responses between the autogenic training group and the control group. There were no significant differences among the groups with regard to HR, VO2, or levels of anxiety. Meditation training may reduce the lactate response to a standardised exercise bout.

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.

Right ventricular pressure response to exercise in adults with isolated ventricular septal defect closed in early childhood.

PubMed

Moller, Thomas; Lindberg, Harald; Lund, May Brit; Holmstrom, Henrik; Dohlen, Gaute; Thaulow, Erik

2018-06-01

We previously demonstrated an abnormally high right ventricular systolic pressure response to exercise in 50% of adolescents operated on for isolated ventricular septal defect. The present study investigated the prevalence of abnormal right ventricular systolic pressure response in 20 adult (age 30-45 years) patients who underwent surgery for early ventricular septal defect closure and its association with impaired ventricular function, pulmonary function, or exercise capacity. The patients underwent cardiopulmonary tests, including exercise stress echocardiography. Five of 19 patients (26%) presented an abnormal right ventricular systolic pressure response to exercise ⩾ 52 mmHg. Right ventricular systolic function was mixed, with normal tricuspid annular plane systolic excursion and fractional area change, but abnormal tricuspid annular systolic motion velocity (median 6.7 cm/second) and isovolumetric acceleration (median 0.8 m/second2). Left ventricular systolic and diastolic function was normal at rest as measured by the peak systolic velocity of the lateral wall and isovolumic acceleration, early diastolic velocity, and ratio of early diastolic flow to tissue velocity, except for ejection fraction (median 53%). The myocardial performance index was abnormal for both the left and right ventricle. Peak oxygen uptake was normal (mean z score -0.4, 95% CI -2.8-0.3). There was no association between an abnormal right ventricular systolic pressure response during exercise and right or left ventricular function, pulmonary function, or exercise capacity. Abnormal right ventricular pressure response is not more frequent in adult patients compared with adolescents. This does not support the theory of progressive pulmonary vascular disease following closure of left-to-right shunts.

A Scoping Review of Physical Performance Outcome Measures Used in Exercise Interventions for Older Adults With Alzheimer Disease and Related Dementias.

PubMed

McGough, Ellen L; Lin, Shih-Yin; Belza, Basia; Becofsky, Katie M; Jones, Dina L; Liu, Minhui; Wilcox, Sara; Logsdon, Rebecca G

2017-11-28

There is growing evidence that exercise interventions can mitigate functional decline and reduce fall risk in older adults with Alzheimer disease and related dementias (ADRD). Although physical performance outcome measures have been successfully used in older adults without cognitive impairment, additional research is needed regarding their use with individuals who have ADRD, and who may have difficulty following instructions regarding performance of these measures. The purpose of this scoping review was to identify commonly used physical performance outcome measures, for exercise interventions, that are responsive and reliable in older adults with ADRD. Ultimately, we aimed to provide recommendations regarding the use of outcome measures for individuals with ADRD across several domains of physical performance. A scoping review was conducted to broadly assess physical performance outcome measures used in exercise interventions for older adults with ADRD. Exercise intervention studies that included at least 1 measure of physical performance were included. All physical performance outcome measures were abstracted, coded, and categorized into 5 domains of physical performance: fitness, functional mobility, gait, balance, and strength. Criteria for recommendations were based on (1) the frequency of use, (2) responsiveness, and (3) reliability. Frequency was determined by the number of studies that used the outcome measure per physical performance domain. Responsiveness was assessed via calculated effect size of the outcome measures across studies within physical performance domains. Reliability was evaluated via published studies of psychometric properties. A total of 20 physical performance outcome measures were extracted from 48 articles that met study inclusion criteria. The most frequently used outcome measures were the 6-minute walk test, Timed Up and Go, repeated chair stand tests, short-distance gait speed, the Berg Balance Scale, and isometric strength measures. These outcome measures demonstrated a small, medium, or large effect in at least 50% of the exercise intervention studies. Good to excellent reliability was reported in samples of older adults with mild to moderate dementia. Fitness, functional mobility, gait, balance, and strength represent important domains of physical performance for older adults. The 6-minute walk test, Timed Up and Go, repeated chair stand tests, short-distance gait speed, Berg Balance Scale, and isometric strength are recommended as commonly used and reliable physical performance outcome measures for exercise interventions in older adults with mild to moderate ADRD. Further research is needed on optimal measures for individuals with severe ADRD. The results of this review will aid clinicians and researchers in selecting reliable measures to evaluate physical performance outcomes in response to exercise interventions in older adults with ADRD.

Acute Effects of Classroom Exercise Breaks on Executive Function and Math Performance: A Dose-Response Study.

PubMed

Howie, Erin K; Schatz, Jeffrey; Pate, Russell R

2015-01-01

The purpose of this study was to determine the acute dose-response relationship of classroom exercise breaks with executive function and math performance in 9- to 12-year-old children by comparing 5-min, 10-min, or 20-min classroom exercise breaks to 10 min of sedentary classroom activity. This study used a within-subjects experimental design conducted in the spring of 2012. Ninety-six 4th- and 5th-grade students in 5 classrooms in South Carolina were randomized to receive each of 4 treatments: 5-min, 10-min, or 20-min exercise breaks or 10 min of a sedentary lesson led by research staff. Students completed the Trail-Making Test, an Operational Digit Recall test, and a math fluency test immediately before and after each condition. Planned linear contrasts were used to compare posttest scores between conditions using a repeated-measures mixed model, adjusted for gender, classroom, and the time-varying pretest scores. Potential effect modifiers were added as interaction terms. Math scores were higher after the 10-min and 20-min exercise breaks compared with the sedentary condition (d = 0.24, p = .04, and d = 0.27, p = .02, respectively), and an interaction was observed with gender, IQ, aerobic fitness, and lower engagement in some of the conditions. There were no improvements in executive function tasks. A 10-min and 20-min classroom exercise break moderately improved math performance in students compared with a seated classroom lesson.

Exercise enhances creativity independently of mood

PubMed Central

Steinberg, Hannah; Sykes, Elizabeth A; Moss, Tim; Lowery, Susan; LeBoutillier, Nick; Dewey, Alison

1997-01-01

Objectives It has been widely accepted in the literature that various forms of physical exercise, even in a single session, enhance positive mood. It has also been shown that physical exercise may sometimes enhance creative thinking, but the evidence is inconclusive. Positive moods can favour creative thinking, but the opposite has also been reported and these relations are unclear. There is a large anecdotal literature suggesting that creative people sometimes use bodily movement to help overcome “blocks”. The aim of this study was to establish whether post-exercise creative thinking was attributable to improved mood. Methods The responses of 63 participants to an exercise (aerobic workout or aerobic dance) and a “neutral” video watching condition were compared. Mood was measured using an adjective list, and creative thinking was tested by three measures of the Torrance test. Results Analysis of variance showed a large and significant increase in positive mood after exercise (P<0.001) and a significant decrease in positive mood after video watching (P<0.001). A significant increase between the creative thinking scores of the two conditions was found on the flexibility (variety of responses) measure (P<0.05). A multifactorial analysis of all data failed to show a significant covariance of creative thinking with the two measures of mood (P>0.05). Conclusions These results suggest that mood and creativity were improved by physical exercise independently of each other. ImagesFigure 1Figure 2 PMID:9298561

Effects of the oral contraceptive pill cycle on physiological responses to hypoxic exercise

NASA Technical Reports Server (NTRS)

Sandoval, Darleen A.; Matt, Kathleen S.

2003-01-01

To test whether the oral contraceptive pill cycle affects endocrine and metabolic responses to hypoxic (fraction of inspired oxygen = 13%, P(IO2): 95 mmHg; H) versus normoxic (P(IO2):153 mmHg; N) exercise, we examined eight women (28 +/- 1.2 yr) during the third (PILL) and placebo (PLA) weeks of their monthly oral contraceptive pill cycle. Cardiopulmonary, metabolic, and neuroendocrine measurements were taken before, during, and after three 5-min consecutive workloads at 30%, 45%, and 60% of normoxic V(O2peak) in H and N trials. Heart rate response to exercise was greater in H versus N, but was not different between PILL and PLA. Lactate levels were significantly greater during exercise, and both lactate and glucose levels were significantly greater for 30 min after exercise in H versus N (p < 0.0001). When expressed relative to baseline, lactate levels were lower in PILL versus PLA, but glucose was greater in PILL versus PLA (p < 0.001). Cortisol levels were also significantly greater in PILL versus PLA (p < 0.001). Norepinephrine levels were significantly increased during exercise (p < 0.0001) and in H versus N (p < 0.0001). However, epinephrine levels were not different over time or with trial. Thus, the presence of circulating estradiol and progesterone during the PILL phase reduces glucose and lactate responses to hypoxic exercise.

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.

Eating in response to exercise cues: Role of self-control fatigue, exercise habits, and eating restraint.

PubMed

Stein, Aliza T; Greathouse, Lee J; Otto, Michael W

2016-01-01

Identifying moderators of compensatory eating is important for understanding the failure of many people to lose weight in response to increased exercise levels. A previous study demonstrated that individuals shown action words (e.g., "active" or "go") were primed by these words to increase energy intake. Further studies have demonstrated that individual differences (e.g. differences in body mass) affect susceptibility to relevant priming cues. Based on these findings, this study examined individual differences, including exercise habits, tendencies toward compensatory eating, dietary restraint, and body mass that may serve as moderators of compensatory eating in the context of conceptual priming. A 2 × 2 design was utilized to analyze the effects of both priming and a self-control task on energy intake. Participants were presented with several snack foods under the guise of a taste test, with energy intake (kcal) during this taste test as the primary outcome variable. Results of this study indicate that, among those with higher baseline levels of exercise, lower energy intake was found for those exposed to exercise cues relative to those who did not receive these cues. In addition, the influence of the self-control fatigue condition was dependent on body mass index. Copyright © 2015 Elsevier Ltd. All rights reserved.

Chronotropic Incompetence and Risk of Atrial Fibrillation: The Henry Ford ExercIse Testing (FIT) Project.

PubMed

O'Neal, Wesley T; Qureshi, Waqas T; Blaha, Michael J; Dardari, Zeina A; Ehrman, Jonathan K; Brawner, Clinton A; Soliman, Elsayed Z; Al-Mallah, Mouaz H

2016-11-01

To examine the association between chronotropic incompetence and incident atrial fibrillation (AF). Patients with inadequate heart rate response during exercise may have abnormalities in sinus node function or autonomic tone that predispose to the development of AF. We examined the association between heart rate response and incident AF in 57,402 (mean age=54±13 years, 47% female, 64% white) patients free of baseline AF who underwent exercise-treadmill stress testing from the Henry Ford ExercIse Testing (FIT) Project. Age-predicted maximum heart rate (pMHR) values <85% and chronotropic index values <80% were used to define chronotropic incompetence. Cox regression, adjusting for demographics, cardiovascular risk factors, medications, coronary heart disease, heart failure, and metabolic equivalent of task achieved, was used to compute hazard ratios (HR) and 95% confidence intervals (CI) for the association between chronotropic incompetence and incident AF. Over a median follow-up of 5.0 years (25 th -75 th percentiles=2.6, 7.8), a total of 3,395 (5.9%) participants developed AF. pMHR values <85% were associated with an increased risk for AF development (HR=1.33, 95%CI=1.22, 1.44). Chronotropic index values <80% also were associated with an increased risk of AF (HR=1.28, 95%CI=1.19, 1.38). The associations of pMHR and chronotropic index with AF remained significant with varying cut-off points to define chronotropic incompetence. Our analysis suggests that patients with inadequate heart rate response during exercise have an increased risk for developing AF.

Positive "alveolar" responses to antigen inhalation provocation tests: their validity and recognition.

PubMed Central

Hendrick, D J; Marshall, R; Faux, J A; Krall, J M

1980-01-01

The validity of inhalation tests in the investigation of extrinsic allergic alveolitis was assessed from the results of 144 antigen and control tests in 31 subjects. A definitive pattern of positive late responses was observed. Reactions to nebulised bird serum and droppings in subjects with bird fancier's lung were identical to reactions after "natural" exposures in aviaries or lofts, and to reactions after "occupational" challenges in subjects with farmer's lung and mushroom worker's lung. In general, positive tests were easily recognised subjectively from symptoms and signs appropriate to an influenza-like illness and undue respiratory effort on exercise. They were associated with significant changes in six readily available objective monitoring measurements--exercise minute ventilation (greater than or equal to +15%), body temperature (> 37.2 degrees C), circulating neutrophils (greater than or equal to +2500/mm3), exercise respiratory frequency (greater than or equal to +25%), circulating lymphocytes (greater than ore equal to -500/mm3 with lymphopenia), and forced vital capacity (greater than or equal to -15%). These confirmatory monitoring tests had specificities of approximately 95% and sensitivities of 85-48%. Measurement of diffusing capacity, lung volume subdivisions, or resting minute ventilation/respiratory frequency proved to be too insensitive to be useful, as did auscultation and chest radiography. We conclude that responses that do provoke significant changes in these less sensitive tests are unnecessarily distressing and, presumable, unnecessarily hazardous. PMID:7434297

Workload differences across command levels and emergency response organizations during a major joint training exercise.

PubMed

Prytz, Erik G; Rybing, Jonas; Jonson, Carl-Oscar

2016-01-01

This study reports on an initial test using a validated workload measurement method, the NASA Task Load Index (TLX), as an indicator of joint emergency exercise effectiveness. Prior research on emergency exercises indicates that exercises must be challenging, ie, result in high workload, to be effective. However, this is often problematic with some participants being underloaded and some overloaded. The NASA TLX was used to test for differences in workload between commanders and subordinates and among three different emergency response organizations during a joint emergency exercise. Questionnaire-based evaluation with professional emergency responders. The study was performed in conjunction with a large-scale interorganizational joint emergency exercise in Sweden. A total of 20 participants from the rescue services, 12 from the emergency medical services, and 12 from the police participated in the study (N=44). Ten participants had a command-level role during the exercise and the remaining 34 were subordinates. The main outcome measures were the workload subscales of the NASA TLX: mental demands, physical demands, temporal demands, performance, effort, and frustration. The results showed that the organizations experienced different levels of workload, that the commanders experienced a higher workload than the subordinates, and that two out of three organizations fell below the twenty-fifth percentile of average workload scores compiled from 237 prior studies. The results support the notion that the NASA TLX could be a useful complementary tool to evaluate exercise designs and outcomes. This should be further explored and verified in additional studies.

Effects of Almond- and Olive Oil-Based Docosahexaenoic- and Vitamin E-Enriched Beverage Dietary Supplementation on Inflammation Associated to Exercise and Age

PubMed Central

Capó, Xavier; Martorell, Miquel; Sureda, Antoni; Riera, Joan; Drobnic, Franchek; Tur, Josep Antoni; Pons, Antoni

2016-01-01

n-3-polyunsaturated fatty acids and polyphenols are potential key factors for the treatment and prevention of chronic inflammation associated to ageing and non-communicable diseases. The aim was to analyse effects of an almond and olive oil beverage enriched with α-tocopherol and docosahexaenoic, exercise and age on inflammatory plasma markers, and immune gene expression in peripheral blood mononuclear cells (PBMCs). Five young and five senior athletes who were supplemented for five weeks with a functional beverage performed a stress test under controlled conditions before and after beverage supplementation. Blood samples were taken immediately before and 1 h after each test. Plasma, erythrocytes and PBMCs were isolated. Beverage supplementation increased plasmatic Tumour Necrosis Factor α (TNFα) levels depending on age and exercise. Exercise increased plasma non esterified fatty acids (NEFAs), soluble Intercellular adhesion molecule 3 (sICAM3) and soluble L-selectin (sL-Selectin), and this increase was attenuated by the supplementation. Exercise increased PGE2 plasma levels in supplemented young and in senior placebo athletes. Exercise increased NFkβ-activated levels in PBMCs, which are primed to a pro-inflammatory response increasing pro-inflammatory genes expression after the exercise mainly in the young group after the supplementation. The functional beverage supplementation to young athletes enhances a pro-inflammatory circulating environment in response to the exercise that was less evident in the senior group. PMID:27735833

Effects of Almond- and Olive Oil-Based Docosahexaenoic- and Vitamin E-Enriched Beverage Dietary Supplementation on Inflammation Associated to Exercise and Age.

PubMed

Capó, Xavier; Martorell, Miquel; Sureda, Antoni; Riera, Joan; Drobnic, Franchek; Tur, Josep Antoni; Pons, Antoni

2016-10-09

n -3-polyunsaturated fatty acids and polyphenols are potential key factors for the treatment and prevention of chronic inflammation associated to ageing and non-communicable diseases. The aim was to analyse effects of an almond and olive oil beverage enriched with α-tocopherol and docosahexaenoic, exercise and age on inflammatory plasma markers, and immune gene expression in peripheral blood mononuclear cells (PBMCs). Five young and five senior athletes who were supplemented for five weeks with a functional beverage performed a stress test under controlled conditions before and after beverage supplementation. Blood samples were taken immediately before and 1 h after each test. Plasma, erythrocytes and PBMCs were isolated. Beverage supplementation increased plasmatic Tumour Necrosis Factor α (TNFα) levels depending on age and exercise. Exercise increased plasma non esterified fatty acids (NEFAs), soluble Intercellular adhesion molecule 3 (sICAM3) and soluble L-selectin (sL-Selectin), and this increase was attenuated by the supplementation. Exercise increased PGE2 plasma levels in supplemented young and in senior placebo athletes. Exercise increased NFkβ-activated levels in PBMCs, which are primed to a pro-inflammatory response increasing pro-inflammatory genes expression after the exercise mainly in the young group after the supplementation. The functional beverage supplementation to young athletes enhances a pro-inflammatory circulating environment in response to the exercise that was less evident in the senior group.

Exaggerated gonadotropin response to luteinizing hormone-releasing hormone in amenorrheic runners.

PubMed

Yahiro, J; Glass, A R; Fears, W B; Ferguson, E W; Vigersky, R A

1987-03-01

Most studies of exercise-induced amenorrhea have compared amenorrheic athletes (usually runners) with sedentary control subjects. Such comparisons will identify hormonal changes that develop as a result of exercise training but cannot determine which of these changes play a role in causing amenorrhea. To obviate this problem, we assessed reproductive hormone status in a group of five amenorrheic runners and compared them to a group of six eumenorrheic runners matched for body fatness, training intensity, and exercise performance. Compared to the eumenorrheic runners, the amenorrheic runners had lower serum estradiol concentrations, similar basal serum luteinizing hormone and follicle-stimulating hormone concentrations, and exaggerated responses of serum gonadotropins after administration of luteinizing hormone-releasing hormone (100 micrograms intravenous bolus). Serum prolactin levels, both basally and after thyrotropin-releasing hormone administration (500 micrograms intravenous bolus) or treadmill exercise, was similar in the two groups, as were serum thyroid function tests (including thyrotropin response to thyrotropin-releasing hormone). Changes in serum cortisol levels after short-term treadmill exercise were similar in both groups, and serum testosterone levels increased after exercise only in the eumenorrheic group. In neither group did such exercise change serum luteinizing hormone, follicle-stimulating hormone, or thyrotropin levels. We concluded that exercise-induced amenorrhea is not solely related to the development of increased prolactin output after exercise training. The exaggerated gonadotropin response to luteinizing hormone-releasing hormone seen in amenorrheic runners in comparison with matched eumenorrheic runners is consistent with a hypothalamic etiology for the menstrual dysfunction, analogous to that previously described in "stress-induced" or "psychogenic" amenorrhea.

CK-MM and ACE genotypes and physiological prediction of the creatine kinase response to exercise.

PubMed

Heled, Yuval; Bloom, Michael S; Wu, T John; Stephens, Quiona; Deuster, Patricia A

2007-08-01

Exertional rhabdomyolysis (ERB) is a syndrome of severe skeletal muscle breakdown. Blood levels of creatine kinase (CK) are widely used as a marker to reflect muscle breakdown. Some individuals exhibit extreme increases in blood CK after exercise and have been characterized as high responders (HR), but no clinical definition of HR exists and reasons for the HR phenomenon are not understood. This study investigated possible associations between the magnitude of the CK response to exercise and polymorphisms of two genes: muscle-specific creatine kinase (CK-MM) NcoI and angiotensin-converting enzyme (ACE) I/D. An exercise test for defining HR was also investigated. Participants (n = 88) underwent an exercise test that included stepping up and down two stairs for 5 min followed by 15 squats while wearing a backpack weighted at 30% of their body weight. CK levels were measured before, immediately after, and 48 and 72 h after the test. Nine participants (10.2%) were defined as HR. Participants with the CK-MM NcoI AA genotype had a sixfold higher risk of being HR compared with GG and AG genotypes (P = 0.031). No significant differences were found for the ACE I/D polymorphism. Percent body fat was an independent predictor of being a HR. We conclude that the CK-MM AA genotype and percent body fat may be part of the constellation of mechanisms that explain susceptibility to ERB. A physiological test that may assist in predicting ERB is also presented.

Exaggerated blood pressure response to early stages of exercise stress testing and presence of hypertension.

PubMed

Schultz, Martin G; Picone, Dean S; Nikolic, Sonja B; Williams, Andrew D; Sharman, James E

2016-12-01

Exaggerated exercise blood pressure (EEBP) recorded during exercise testing at moderate-intensity is independently associated with cardiovascular mortality. It is hypothesized that EEBP may be indicative of underlying hypertension unnoticed by standard clinic (resting) BP measures (thus explaining increased mortality risk), but this has never been confirmed by association with hypertension defined using ambulatory BP monitoring, which was the aim of this study. Cross-sectional study. 100 consecutive patients free from coronary artery disease (aged 56±9 years, 72% male) underwent clinically indicated exercise stress testing. Exercise BP was recorded at each stage of the Bruce protocol. Presence of hypertension was defined as 24-hour systolic BP ≥130mmHg or daytime systolic BP ≥135mmHg. Exercise systolic BP at stage 1 and 2 of the test was significantly associated with the presence of hypertension (P<0.05), with the strongest association observed between stage 1 exercise systolic BP and 24-h systolic BP >130mmHg (AUC=0.752, 95% CI's 0.649-0.846, P<0.001). 79% of participants achieving systolic BP ≥150mmHg at stage 1 of the test were classified as having hypertension, with systolic BP >150mmHg predicting hypertension independently of age, sex and in-clinic hypertension status (OR=4.83, 95% CI's 1.62-14.39, P=0.005). Irrespective of resting BP, systolic BP ≥150mmHg during early stages of the Bruce exercise stress test is associated with presence of hypertension. EEBP should be a warning signal to health/exercise professionals on the presence of hypertension and the need to provide follow up care to reduce cardiovascular risk. Copyright © 2016 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

The Effect of Estrogen Usage on Eccentric Exercise-Induced Damage in Rat Testes

PubMed Central

Can, Serpil; Selli, Jale; Buyuk, Basak; Aydin, Sergulen; Kocaaslan, Ramazan; Guvendi, Gulname Findik

2015-01-01

Background: Recent years, lots of scientific studies are focused on the possible mechanism of inflammatory response and oxidative stress which are the mechanism related with tissue damage and exercise fatigue. It is well-known that free oxygen radicals may be induced under invitro conditions as well as oxidative stress by exhaustive physical exercise. Objectives: The aim of this study was to investigate the effects of anabolic steroids in conjunction with exercise in the process of spermatogenesis in the testes, using histological and stereological methods. Materials and Methods: Thirty-six male Sprague Dawley rats were divided to six groups, including the control group, the eccentric exercise administered group, the estrogen applied group, the estrogen applied and dissected one hour after eccentric exercise group, the no estrogen applied and dissected 48 hours after eccentric exercise group and the estrogen applied and dissected 48 hours after eccentric exercise group. Eccentric exercise was performed on a motorized rodent treadmill and the estrogen applied groups received daily physiological doses by subcutaneous injections. Testicular tissues were examined using specific histopathological, immunohistochemical and stereological methods. Sections of the testes tissue were stained using the TUNEL method to identify apoptotic cells. Apoptosis was calculated as the percentage of positive cells, using stereological analysis. A statistical analysis of the data was carried out with one-way analysis of variance (ANOVA) for the data obtained from stereological analysis. Results: Conventional light microscopic results revealed that testes tissues of the eccentric exercise administered group and the estrogen supplemented group exhibited slight impairment. In groups that were both eccentrically exercised and estrogen supplemented, more deterioration was detected in testes tissues. Likewise, immunohistochemistry findings were also more prominent in the eccentrically exercised and estrogen supplemented groups. Conclusions: The findings suggest that estrogen supplementation increases damage in testicular tissue due to eccentric exercise. PMID:26023337

Exercise Training During +Gz Acceleration

NASA Technical Reports Server (NTRS)

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

1999-01-01

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

Study in Parkinson Disease of Exercise (SPARX): Translating high-intensity exercise from animals to humans

PubMed Central

Moore, Charity G.; Schenkman, Margaret; Kohrt, Wendy M.; Delitto, Anthony; Hall, Deborah A.; Corcos, Daniel

2013-01-01

A burgeoning literature suggests that exercise has a therapeutic benefit in persons with Parkinson disease (PD) and in animal models of PD, especially when animals exercise at high intensity. If exercise is to be prescribed as “first-line” or “add-on” therapy in patients with PD, we must demonstrate its efficacy and dose-response effects through testing phases similar to those used in the testing of pharmacologic agents. The SPARX Trial is a multicenter, randomized, controlled, single-blinded, Phase II study that we designed to test the feasibility of using high-intensity exercise to modify symptoms of PD and to simultaneously test the nonfutility of achieving a prespecified change in patients’ motor scores on the Unified Parkinson Disease Rating Scale (UPDRS). The trial began in May 2102 and is in the process of screening, enrolling, and randomly assigning 126 patients with early-stage PD to 1 of 3 groups: usual care (wait-listed controls), moderate-intensity exercise (4 days/week at 60%–65% maximal heart rate [HRmax]), or high-intensity exercise (4 days/week at 80%–85% HRmax). At 6-month follow-up, the trial is randomly reassigning usual care participants to a moderate-intensity or high-intensity exercise group for the remaining 6 months. The goals of the Phase II trial are to determine if participants can exercise at moderate and high intensities; to determine if either exercise yields benefits consistent with meaningful clinical change (nonfutility); and to document safety and attrition. The advantage of using a non-futility approach allows us to efficiently determine if moderate- or high-intensity exercise warrants further large-scale investigation in PD. PMID:23770108

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

Muscle fibre characteristics and lactate responses to exercise in chronic fatigue syndrome.

PubMed

Lane, R J; Barrett, M C; Woodrow, D; Moss, J; Fletcher, R; Archard, L C

1998-03-01

To examine the proportions of type 1 and type 2 muscle fibres and the degree of muscle fibre atrophy and hypertrophy in patients with chronic fatigue syndrome in relation to lactate responses to exercise, and to determine to what extent any abnormalities found might be due to inactivity. Quadriceps needle muscle biopsies were obtained from 105 patients with chronic fatigue syndrome and the proportions of type 1 and 2 fibres and fibre atrophy and hypertrophy factors were determined from histochemical preparations, using a semiautomated image analysis system. Forty one randomly selected biopsies were also examined by electron microscopy. Lactate responses to exercise were measured in the subanaerobic threshold exercise test (SATET). Inactivity would be expected to result in a shift to type 2 fibre predominance and fibre atrophy, but type 1 predominance (23%) was more common than type 2 predominance (3%), and fibre atrophy was found in only 10.4% of cases. Patients with increased lactate responses to exercise did have significantly fewer type 1 muscle fibres (p<0.043 males, p<0.0003 females), but there was no evidence that this group was less active than the patients with normal lactate responses. No significant ultrastructural abnormalities were found. Muscle histometry in patients with chronic fatigue syndrome generally did not show the changes expected as a result of inactivity. However, patients with abnormal lactate responses to exercise had a significantly lower proportion of mitochondria rich type 1 muscle fibres.

Exaggerated exercise blood pressure response in middle-aged men as a predictor of future blood pressure: a 10-year follow-up.

PubMed

Ito, Katsuyuki; Iwane, Masataka; Miyai, Nobuyuki; Uchikawa, Yukiko; Mugitani, Koichi; Mohara, Osamu; Shiba, Mitsuru; Arita, Mikio

The prognostic value of an exaggerated exercise systolic blood pressure response (EESBPR) remains controversial. This study was designed to assess whether an EESBPR is associated with the predictor of future blood pressure. From an initial population of 1,534 male-subjects with normal BP or no medication who underwent ergometric exercise, 733 subjects (mean age: 41 years old) at baseline to follow-up BP after an average of 10 years were selected. A 12-min exercise tolerance test with three phases of estimated load from predictive maximum oxygen intake was performed at baseline, and exercise BP was measured. Exercise BP response was classified by three group: Low group (G) (exercise SBP < 180 mmHg), Middle G (exercise BP:180-199 mmHg), High G (exercise BP:200 mmHg ≦). BP after 10 years in Low G was 123 ± 12/79 ± 7 mmHg, in Middle G:127 ± 13/81 ± 8 mmHg, in High G :134 ± 15/84 ± 10 mmHg. Compared with in Low G, BP after 10 years in High G significantly increased (p < 0.05). Multiple regression analysis was carried out to clarify the relationship of exercise SBP at baseline to BP after 10 years. In multivariate-adjusted models, the relationship of SBP at follow-up was stronger to exercise SBP (β = 0.271, P < 0.001) than to resting SBP (β = 0.148, P < 0.001). Maximum oxygen intake (β = -0.193, P = 0.003) and resting SBP correlated with SBP after 10 years. In middle-aged men, exercise SBP would be a stronger predictor of future SBP, DBP rather than BP at rest. In optimal of classification of BP (SBP < 120 mmHg), exercise BP response was clearly associated with BP after 10 years.

Exercise Experiences and Changes in Affective Attitude: Direct and Indirect Effects of In Situ Measurements of Experiences

PubMed Central

Sudeck, Gorden; Schmid, Julia; Conzelmann, Achim

2016-01-01

Objectives: The purpose of this study was to examine the relationship between exercise experiences (perceptions of competence, perceived exertion, acute affective responses to exercise) and affective attitudes toward exercise. This relationship was analyzed in a non-laboratory setting during a 13-weeks exercise program. Materials and Methods: 56 women and 49 men (aged 35–65 years; Mage = 50.0 years; SD = 8.2 years) took part in the longitudinal study. Affective responses to exercise (affective valence, positive activation, calmness) as well as perceptions of competence and perceived exertion were measured at the beginning, during, and end of three exercise sessions within the 13-weeks exercise program. Affective attitude toward exercise were measured before and at the end of the exercise program. A two-level path analysis was conducted. The direct and indirect effects of exercise experiences on changes in affective attitude were analyzed on the between-person level: firstly, it was tested whether perceptions of competence and perceived exertion directly relate to changes in affective attitude. Secondly, it was assessed whether perceptions of competence and perceived exertion indirectly relate to changes in affective attitudes—imparted via the affective response during exercise. Results and Conclusion: At the between-person level, a direct effect on changes in affective attitude was found for perceptions of competence (β = 0.24, p < 0.05). The model revealed one significant indirect pathway between perceived exertion and changes in affective attitude via positive activation: on average, the less strenuous people perceive physical exercise to be, the more awake they will feel during exercise (β = -0.57, p < 0.05). Those people with higher average levels of positive activation during exercise exhibit more improvements in affective attitudes toward exercise from the beginning to the end of the 13-weeks exercise program (β = 0.24, p < 0.05). Main study results have revealed that in situ experiences predicted changes in affective attitude during multi-week exercise programs. These relevant in situ experiences encompass cognitive factors, the sensation of interoceptive cues, and affective responses to exercise. Considering the predictive role of affective attitudes for exercise behavior, these findings suggest that exercise interventions should put greater emphasis on specific exercise experiences. PMID:27378992

Regular physical exercise improves cardiac autonomic and muscle vasodilatory responses to isometric exercise in healthy elderly.

PubMed

Sarmento, Adriana de Oliveira; Santos, Amilton da Cruz; Trombetta, Ivani Credidio; Dantas, Marciano Moacir; Oliveira Marques, Ana Cristina; do Nascimento, Leone Severino; Barbosa, Bruno Teixeira; Dos Santos, Marcelo Rodrigues; Andrade, Maria do Amparo; Jaguaribe-Lima, Anna Myrna; Brasileiro-Santos, Maria do Socorro

2017-01-01

The objective of this study was to evaluate cardiac autonomic control and muscle vasodilation response during isometric exercise in sedentary and physically active older adults. Twenty healthy participants, 10 sedentary and 10 physically active older adults, were evaluated and paired by gender, age, and body mass index. Sympathetic and parasympathetic cardiac activity (spectral and symbolic heart rate analysis) and muscle blood flow (venous occlusion plethysmography) were measured for 10 minutes at rest (baseline) and during 3 minutes of isometric handgrip exercise at 30% of the maximum voluntary contraction (sympathetic excitatory maneuver). Variables were analyzed at baseline and during 3 minutes of isometric exercise. Cardiac autonomic parameters were analyzed by Wilcoxon and Mann-Whitney tests. Muscle vasodilatory response was analyzed by repeated-measures analysis of variance followed by Tukey's post hoc test. Sedentary older adults had higher cardiac sympathetic activity compared to physically active older adult subjects at baseline (63.13±3.31 vs 50.45±3.55 nu, P =0.02). The variance (heart rate variability index) was increased in active older adults (1,438.64±448.90 vs 1,402.92±385.14 ms, P =0.02), and cardiac sympathetic activity (symbolic analysis) was increased in sedentary older adults (5,660.91±1,626.72 vs 4,381.35±1,852.87, P =0.03) during isometric handgrip exercise. Sedentary older adults showed higher cardiac sympathetic activity (spectral analysis) (71.29±4.40 vs 58.30±3.50 nu, P =0.03) and lower parasympathetic modulation (28.79±4.37 vs 41.77±3.47 nu, P =0.03) compared to physically active older adult subjects during isometric handgrip exercise. Regarding muscle vasodilation response, there was an increase in the skeletal muscle blood flow in the second (4.1±0.5 vs 3.7±0.4 mL/min per 100 mL, P =0.01) and third minute (4.4±0.4 vs 3.9±0.3 mL/min per 100 mL, P =0.03) of handgrip exercise in active older adults. The results indicate that regular physical activity improves neurovascular control of muscle blood flow and cardiac autonomic response during isometric handgrip exercise in healthy older adult subjects.

Regular physical exercise improves cardiac autonomic and muscle vasodilatory responses to isometric exercise in healthy elderly

PubMed Central

Sarmento, Adriana de Oliveira; Santos, Amilton da Cruz; Trombetta, Ivani Credidio; Dantas, Marciano Moacir; Oliveira Marques, Ana Cristina; do Nascimento, Leone Severino; Barbosa, Bruno Teixeira; Dos Santos, Marcelo Rodrigues; Andrade, Maria do Amparo; Jaguaribe-Lima, Anna Myrna; Brasileiro-Santos, Maria do Socorro

2017-01-01

The objective of this study was to evaluate cardiac autonomic control and muscle vasodilation response during isometric exercise in sedentary and physically active older adults. Twenty healthy participants, 10 sedentary and 10 physically active older adults, were evaluated and paired by gender, age, and body mass index. Sympathetic and parasympathetic cardiac activity (spectral and symbolic heart rate analysis) and muscle blood flow (venous occlusion plethysmography) were measured for 10 minutes at rest (baseline) and during 3 minutes of isometric handgrip exercise at 30% of the maximum voluntary contraction (sympathetic excitatory maneuver). Variables were analyzed at baseline and during 3 minutes of isometric exercise. Cardiac autonomic parameters were analyzed by Wilcoxon and Mann–Whitney tests. Muscle vasodilatory response was analyzed by repeated-measures analysis of variance followed by Tukey’s post hoc test. Sedentary older adults had higher cardiac sympathetic activity compared to physically active older adult subjects at baseline (63.13±3.31 vs 50.45±3.55 nu, P=0.02). The variance (heart rate variability index) was increased in active older adults (1,438.64±448.90 vs 1,402.92±385.14 ms, P=0.02), and cardiac sympathetic activity (symbolic analysis) was increased in sedentary older adults (5,660.91±1,626.72 vs 4,381.35±1,852.87, P=0.03) during isometric handgrip exercise. Sedentary older adults showed higher cardiac sympathetic activity (spectral analysis) (71.29±4.40 vs 58.30±3.50 nu, P=0.03) and lower parasympathetic modulation (28.79±4.37 vs 41.77±3.47 nu, P=0.03) compared to physically active older adult subjects during isometric handgrip exercise. Regarding muscle vasodilation response, there was an increase in the skeletal muscle blood flow in the second (4.1±0.5 vs 3.7±0.4 mL/min per 100 mL, P=0.01) and third minute (4.4±0.4 vs 3.9±0.3 mL/min per 100 mL, P=0.03) of handgrip exercise in active older adults. The results indicate that regular physical activity improves neurovascular control of muscle blood flow and cardiac autonomic response during isometric handgrip exercise in healthy older adult subjects. PMID:28721030

Endogenous pain modulation in response to exercise in patients with rheumatoid arthritis, patients with chronic fatigue syndrome and comorbid fibromyalgia, and healthy controls: a double-blind randomized controlled trial.

PubMed

Meeus, Mira; Hermans, Linda; Ickmans, Kelly; Struyf, Filip; Van Cauwenbergh, Deborah; Bronckaerts, Laura; De Clerck, Luc S; Moorken, Greta; Hans, Guy; Grosemans, Sofie; Nijs, Jo

2015-02-01

Temporal summation (TS) of pain, conditioned pain modulation (CPM), and exercise-induced analgesia (EIA) are often investigated in chronic pain populations as an indicator for enhanced pain facilitation and impaired endogenous pain inhibition, respectively, but interactions are not yet clear both in healthy controls and in chronic pain patients. Therefore, the present double-blind randomized placebo-controlled study evaluates pains cores, TS, and CPM in response to exercise in healthy controls, patients with chronic fatigue syndrome and comorbid fibromyalgia (CFS/FM), and patients with rheumatoid arthritis (RA), both under placebo and paracetamol condition. Fifty-three female volunteers - of which 19 patients with CFS/FM, 16 patients with RA, and 18 healthy controls - underwent a submaximal exercise test on a bicycle ergometer on 2 different occasions (paracetamol vs. placebo), with an interval of 7 days. Before and after exercise, participants rated pain intensity during TS and CPM. Patients with rheumatoid arthritis showed decreased TS after exercise, both after paracetamol and placebo (P < 0.05). In patients with CFS/FM, results were less univocal. A nonsignificant decrease in TS was only observed after taking paracetamol. CPM responses to exercise are inconclusive, but seem to worsen after exercise. No adverse effects were seen. This study evaluates pain scores, TS, and CPM in response to submaximal exercise in 2 different chronic pain populations and healthy controls. In patients with RA, exercise had positive effects on TS, suggesting normal EIA. In patients with CFS/FM, these positive effects were only observed after paracetamol and results were inconsistent. © 2014 World Institute of Pain.

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.

Predicting short and long-term exercise intentions and behaviour in patients with coronary artery disease: A test of protection motivation theory.

PubMed

Tulloch, Heather; Reida, Robert; D'Angeloa, Monika Slovinec; Plotnikoff, Ronald C; Morrina, Louise; Beatona, Louise; Papadakisa, Sophia; Pipe, Andrew

2009-03-01

The purpose of this study was to examine the utility of protection motivation theory (PMT) in the prediction of exercise intentions and behaviour in the year following hospitalisation for coronary artery disease (CAD). Patients with documented CAD (n = 787), recruited at hospital discharge, completed questionnaires measuring PMT's threat (i.e. perceived severity and vulnerability) and coping (i.e. self-efficacy, response efficacy) appraisal constructs at baseline, 2 and 6 months, and exercise behaviour at baseline, 6 and 12 months post-hospitalisation. Structural equation modelling showed that the PMT model of exercise at 6 months had a good fit with the empirical data. Self-efficacy, response efficacy, and perceived severity predicted exercise intentions, which, in turn predicted exercise behaviour. Overall, the PMT variables accounted for a moderate amount of variance in exercise intentions (23%) and behaviour (20%). In contrast, the PMT model was not reliable for predicting exercise behaviour at 12 months post-hospitalisation. The data provided support for PMT applied to short-term, but not long-term, exercise behaviour among patients with CAD. Health education should concentrate on providing positive coping messages to enhance patients' confidence regarding exercise and their belief that exercise provides health benefits, as well as realistic information about disease severity.

The higher exercise intensity and the presence of allele I of ACE gene elicit a higher post-exercise blood pressure reduction and nitric oxide release in elderly women: an experimental study.

PubMed

Santana, Hugo A P; Moreira, Sérgio R; Neto, Willson B; Silva, Carla B; Sales, Marcelo M; Oliveira, Vanessa N; Asano, Ricardo Y; Espíndola, Foued S; Nóbrega, Otávio T; Campbell, Carmen S G; Simões, Herbert G

2011-12-02

The absence of the I allele of the angiotensin converting enzyme (ACE) gene has been associated with higher levels of circulating ACE, lower nitric oxide (NO) release and hypertension. The purposes of this study were to analyze the post-exercise salivary nitrite (NO2-) and blood pressure (BP) responses to different exercise intensities in elderly women divided according to their ACE genotype. Participants (n = 30; II/ID = 20 and DD = 10) underwent three experimental sessions: incremental test - IT (15 watts workload increase/3 min) until exhaustion; 20 min exercise 90% anaerobic threshold (90% AT); and 20 min control session without exercise. Volunteers had their BP and NO2- measured before and after experimental sessions. Despite both intensities showed protective effect on preventing the increase of BP during post-exercise recovery compared to control, post-exercise hypotension and increased NO2- release was observed only for carriers of the I allele (p < 0.05). Genotypes of the ACE gene may exert a role in post-exercise NO release and BP response.

Effects of Performance Versus Game-Based Mobile Applications on Response to Exercise.

PubMed

Gillman, Arielle S; Bryan, Angela D

2016-02-01

Given the popularity of mobile applications (apps) designed to increase exercise participation, it is important to understand their effects on psychological predictors of exercise behavior. This study tested a performance feedback-based app compared to a game-based app to examine their effects on aspects of immediate response to an exercise bout. Twenty-eight participants completed a 30-min treadmill run while using one of two randomly assigned mobile running apps: Nike + Running, a performance-monitoring app which theoretically induces an associative, goal-driven state, or Zombies Run!, an app which turns the experience of running into a virtual reality game, theoretically inducing dissociation from primary exercise goals. The two conditions did not differ on primary motivational state outcomes; however, participants reported more associative attentional focus in the performance-monitoring app condition compared to more dissociative focus in the game-based app condition. Game-based and performance-tracking running apps may not have differential effects on goal motivation during exercise. However, game-based apps may help recreational exercisers dissociate from exercise more readily. Increasing the enjoyment of an exercise bout through the development of new and innovative mobile technologies is an important avenue for future research.

Endurance- and Resistance-Trained Men Exhibit Lower Cardiovascular Responses to Psychosocial Stress Than Untrained Men.

PubMed

Gröpel, Peter; Urner, Maren; Pruessner, Jens C; Quirin, Markus

2018-01-01

Evidence shows that regular physical exercise reduces physiological reactivity to psychosocial stress. However, previous research mainly focused on the effect of endurance exercise, with only a few studies looking at the effect of resistance exercise. The current study tested whether individuals who regularly participate in either endurance or resistance training differ from untrained individuals in adrenal and cardiovascular reactivity to psychosocial stress. Twelve endurance-trained men, 10 resistance-trained men, and 12 healthy but untrained men were exposed to a standardized psychosocial stressor, the Trier Social Stress Test. Measurements of heart rate, free salivary cortisol levels, and mood were obtained throughout the test and compared among the three groups. Overall, both endurance- and resistance-trained men had lower heart rate levels than untrained men, indicating higher cardiac performance of the trained groups. Trained men also exhibited lower heart rate responses to psychosocial stress compared with untrained men. There were no significant group differences in either cortisol responses or mood responses to the stressor. The heart rate results are consistent with previous studies indicating reduced cardiovascular reactivity to psychosocial stress in trained individuals. These findings suggest that long-term endurance and resistance trainings may be related to the same cardiovascular benefits, without exhibiting strong effects on the cortisol reactivity to stress.

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.

Using exercises to improve public health preparedness in Asia, the Middle East and Africa

PubMed Central

2014-01-01

Background Exercises are increasingly common tools used by the health sector and other sectors to evaluate their preparedness to respond to public health threats. Exercises provide an opportunity for multiple sectors to practice, test and evaluate their response to all types of public health emergencies. The information from these exercises can be used to refine and improve preparedness plans. There is a growing body of literature about the use of exercises among local, state and federal public health agencies in the United States. There is much less information about the use of exercises among public health agencies in other countries and the use of exercises that involve multiple countries. Results We developed and conducted 12 exercises (four sub-national, five national, three sub-regional) from August 2006 through December 2008. These 12 exercises included 558 participants (average 47) and 137 observers (average 11) from 14 countries. Participants consistently rated the overall quality of the exercises as very good or excellent. They rated the exercises lowest on their ability to identifying key gaps in performance. The vast majority of participants noted that they would use the information they gained at the exercise to improve their organization’s preparedness to respond to an influenza pandemic. Participants felt the exercises were particularly good at raising awareness and understanding about public health threats, assisting in evaluating plans and identifying priorities for improvement, and building relationships that strengthen preparedness and response across sectors and across countries. Participants left the exercises with specific ideas about the most important actions that they should engage in after the exercise such as improved planning coordination across sectors and countries and better training of health workers and response personnel. Conclusions These experiences suggest that exercises can be a valuable, low-burden tool to improve emergency preparedness and response in countries around the world. They also demonstrate that countries can work together to develop and conduct successful exercises designed to improve regional preparedness to public health threats. The development of standardized evaluation methods for exercises may be an additional tool to help focus the actions to be taken as a result of the exercise and to improve future exercises. Exercises show great promise as tools to improve public health preparedness across sectors and countries. PMID:25063987

Resistance Exercise Attenuates High-Fructose, High-Fat-Induced Postprandial Lipemia

PubMed Central

Wilburn, Jessie R; Bourquin, Jeffrey; Wysong, Andrea; Melby, Christopher L

2015-01-01

INTRODUCTION Meals rich in both fructose and fat are commonly consumed by many Americans, especially young men, which can produce a significant postprandial lipemic response. Increasing evidence suggests that aerobic exercise can attenuate the postprandial increase in plasma triacylglycerols (TAGs) in response to a high-fat or a high-fructose meal. However, it is unknown if resistance exercise can dampen the postprandial lipemic response to a meal rich in both fructose and fat. METHODS Eight apparently healthy men (Mean ± SEM; age = 27 ± 2 years) participated in a crossover study to examine the effects of acute resistance exercise on next-day postprandial lipemia resulting from a high-fructose, high-fat meal. Participants completed three separate two-day conditions in a random order: (1) EX-COMP: a full-body weightlifting workout with the provision of additional kilocalories to compensate for the estimated net energy cost of exercise on day 1, followed by the consumption of a high-fructose, high-fat liquid test meal the next morning (day 2) (~600 kcal) and the determination of the plasma glucose, lactate, insulin, and TAG responses during a six-hour postprandial period; (2) EX-DEF: same condition as EX-COMP but without exercise energy compensation on day 1; and (3) CON: no exercise control. RESULTS The six-hour postprandial plasma insulin and lactate responses did not differ between conditions. However, the postprandial plasma TAG concentrations were 16.5% and 24.4% lower for EX-COMP (551.0 ± 80.5 mg/dL × 360 minutes) and EX-DEF (499.4 ± 73.5 mg/dL × 360 minutes), respectively, compared to CON (660.2 ± 95.0 mg/dL × 360 minutes) (P < 0.05). CONCLUSIONS A single resistance exercise bout, performed ~15 hours prior to a high-fructose, high-fat meal, attenuated the postprandial TAG response, as compared to a no-exercise control condition, in healthy, resistance-trained men. PMID:26508874

Resistance Exercise Attenuates High-Fructose, High-Fat-Induced Postprandial Lipemia.

PubMed

Wilburn, Jessie R; Bourquin, Jeffrey; Wysong, Andrea; Melby, Christopher L

2015-01-01

Meals rich in both fructose and fat are commonly consumed by many Americans, especially young men, which can produce a significant postprandial lipemic response. Increasing evidence suggests that aerobic exercise can attenuate the postprandial increase in plasma triacylglycerols (TAGs) in response to a high-fat or a high-fructose meal. However, it is unknown if resistance exercise can dampen the postprandial lipemic response to a meal rich in both fructose and fat. Eight apparently healthy men (Mean ± SEM; age = 27 ± 2 years) participated in a crossover study to examine the effects of acute resistance exercise on next-day postprandial lipemia resulting from a high-fructose, high-fat meal. Participants completed three separate two-day conditions in a random order: (1) EX-COMP: a full-body weightlifting workout with the provision of additional kilocalories to compensate for the estimated net energy cost of exercise on day 1, followed by the consumption of a high-fructose, high-fat liquid test meal the next morning (day 2) (~600 kcal) and the determination of the plasma glucose, lactate, insulin, and TAG responses during a six-hour postprandial period; (2) EX-DEF: same condition as EX-COMP but without exercise energy compensation on day 1; and (3) CON: no exercise control. The six-hour postprandial plasma insulin and lactate responses did not differ between conditions. However, the postprandial plasma TAG concentrations were 16.5% and 24.4% lower for EX-COMP (551.0 ± 80.5 mg/dL × 360 minutes) and EX-DEF (499.4 ± 73.5 mg/dL × 360 minutes), respectively, compared to CON (660.2 ± 95.0 mg/dL × 360 minutes) (P < 0.05). A single resistance exercise bout, performed ~15 hours prior to a high-fructose, high-fat meal, attenuated the postprandial TAG response, as compared to a no-exercise control condition, in healthy, resistance-trained men.

Neurovascular Response during Exercise and Mental Stress in Anabolic Steroid Users.

PubMed

Porello, Rafael Armani; Dos Santos, Marcelo Rodrigues; DE Souza, Francis Ribeiro; DA Fonseca, Guilherme Wesley Peixoto; Sayegh, Ana Luiza Carrari; DE Oliveira, Tiago Franco; Akiho, César Abreu; Yonamine, Maurício; Pereira, Rosa Maria Rodrigues; Negrão, Carlos Eduardo; Alves, Maria-Janieire DE Nazaré Nunes

2018-03-01

Increased resting muscle sympathetic nerve activity (MSNA) and lower forearm blood flow (FBF) were observed in young men who use anabolic androgenic steroids (AAS). However, the response of MSNA and FBF in AAS users triggered by muscle mechanoreflex and central command has never been tested. In addition, we evaluated the blood pressure (BP) and heart rate (HR) responses during these maneuvers. Nineteen AAS users (AASU) 31 ± 6 yr of age and 18 AAS nonusers (AASNU) 29 ± 4 yr of age were recruited. All participants were involved in strength training. AAS use was determined using a urine test (liquid chromatography with tandem mass spectrometry). MSNA was measured using the microneurography technique. FBF was measured by using venous occlusion plethysmography. BP was measured using an automatic oscillometric device. HR was recorded continuously through ECG. Isometric handgrip exercise was performed at 30% of the maximal voluntary contraction for 3 min, and mental stress was elicited by the Stroop color-word test for 4 min. The MSNA and FBF responses during exercise were similar between AASU and AASNU, with a trend toward higher MSNA (bursts per minute; P = 0.084) and lower forearm vascular conductance (FVC; units; P = 0.084) in AASU than in AASNU. During mental stress, AASU showed a significantly higher MSNA (P < 0.05) and lower FBF (P < 0.05) compared with AASNU. During both maneuvers, HR and BP increased linearly in both groups; however, AASU showed a significantly higher HR compared with AASNU. During muscle mechanoreflex activation (isometric exercise), AASU have normal MSNA and FBF responses, whereas during central command (mental stress) stimulation, AASU have exacerbated MSNA and blunted vasodilation. Therefore, mental stress seems to exacerbate neurovascular control throughout stress reaction situations in AASU.

Absence of resting cardiovascular dysfunction in middle-aged endurance-trained athletes with exaggerated exercise blood pressure responses.

PubMed

Currie, Katharine D; Sless, Ryan T; Notarius, Catherine F; Thomas, Scott G; Goodman, Jack M

2017-08-01

Untrained individuals with exaggerated blood pressure (EBP) responses to graded exercise testing are characterized as having resting dysfunction of the sympathetic and cardiovascular systems. The purpose of this study was to determine the resting cardiovascular state of endurance-trained individuals with EBP through a comparison of normotensive athletes with and without EBP. EBP was defined as a maximal systolic blood pressure (SBP) at least 190 mmHg and at least 210 mmHg for women and men respectively, in response to a graded exercise test. Twenty-two life-long endurance-trained athletes (56 ± 5 years, 16 men) with EBP (EBP+) and 11 age and sex-matched athletes (55 ± 5 years, eight men) without EBP (EBP-) participated in the study. Sympathetic reactivity was assessed using BP responses to a cold pressor test, isometric handgrip exercise, and postexercise muscle ischemia. Resting left ventricular structure and function was assessed using two-dimensional echocardiography, whereas central arterial stiffness was assessed using carotid-to-femoral pulse wave velocity. Calf vascular conductance was measured at rest and peak postexercise using strain-gauge plethysmography. All sympathetic reactivity, left ventricular, and arterial stiffness indices were similar between groups. There was no between-group difference in resting vascular conductance, whereas peak vascular conductance was higher in EBP+ relative to EBP- (1.81 ± 0.65 vs. 1.45 ± 0.32 ml/100 ml/min/mmHg, P < 0.05). Findings from this study suggest that athletes with EBP do not display the resting cardiovascular state typically observed in untrained individuals with EBP. This response in athletes, therefore, is likely a compensatory mechanism to satisfy peripheral blood-flow demands rather than indicative of latent dysfunction.

Dose-response effects of aerobic exercise on estrogen among women at high risk for breast cancer: a randomized controlled trial.

PubMed

Schmitz, Kathryn H; Williams, Nancy I; Kontos, Despina; Domchek, Susan; Morales, Knashawn H; Hwang, Wei-Ting; Grant, Lorita L; DiGiovanni, Laura; Salvatore, Domenick; Fenderson, Desire'; Schnall, Mitchell; Galantino, Mary Lou; Stopfer, Jill; Kurzer, Mindy S; Wu, Shandong; Adelman, Jessica; Brown, Justin C; Good, Jerene

2015-11-01

Medical and surgical interventions for elevated breast cancer risk (e.g., BRCA1/2 mutation, family history) focus on reducing estrogen exposure. Women at elevated risk may be interested in less aggressive approaches to risk reduction. For example, exercise might reduce estrogen, yet has fewer serious side effects and less negative impact than surgery or hormonal medications. Randomized controlled trial. Increased risk defined by risk prediction models or BRCA mutation status. Eligibility: Age 18-50, eumenorrheic, non-smokers, and body mass index (BMI) between 21 and 50 kg/m(2). 139 were randomized. Treadmill exercise: 150 or 300 min/week, five menstrual cycles. Control group maintained exercise <75 min/week. Area under curve (AUC) for urinary estrogen. Secondary measures: urinary progesterone, quantitative digitized breast dynamic contrast-enhanced magnetic resonance imaging background parenchymal enhancement. Mean age 34 years, mean BMI 26.8 kg/m(2). A linear dose-response relationship was observed such that every 100 min of exercise is associated with 3.6 % lower follicular phase estrogen AUC (linear trend test, p = 0.03). No changes in luteal phase estrogen or progesterone levels. There was also a dose-response effect noted: for every 100 min of exercise, there was a 9.7 % decrease in background parenchymal enhancement as measured by imaging (linear trend test, p = 0.009). Linear dose-response effect observed to reduce follicular phase estrogen exposure measured via urine and hormone sensitive breast tissue as measured by imaging. Future research should explore maintenance of effects and extent to which findings are repeatable in lower risk women. Given the high benefit to risk ratio, clinicians can inform young women at increased risk that exercise may blunt estrogen exposure while considering whether to try other preventive therapies.

Aspirin enhances the induction of type I allergic symptoms when combined with food and exercise in patients with food-dependent exercise-induced anaphylaxis.

PubMed

Harada, S; Horikawa, T; Ashida, M; Kamo, T; Nishioka, E; Ichihashi, M

2001-08-01

We examined the effect of aspirin as a substitute for exercise in inducing urticaria/anaphylaxis in three patients with food-dependent exercise-induced anaphylaxis (FDEIA). Two of the patients had specific IgE antibodies to wheat and the other had antibodies to shrimp. Administration of aspirin before ingestion of food allergens induced urticaria in one patient and urticaria and hypotension in another, while aspirin alone or food alone elicited no response. The third patient developed urticaria only when he took all three items, i.e. aspirin, food and additional exercise, whereas provocation with any one or or two of these did not induce any symptoms. These findings suggest that aspirin upregulates type I allergic responses to food in patients with FDEIA, and further shows that aspirin synergizes with exercise to provoke symptoms of FDEIA. This is the first report of a synergistic effect of aspirin in inducing urticaria/anaphylaxis, which was confirmed using challenge tests in patients with FDEIA.

Prospective evaluation of a new protocol for the provisional use of perfusion imaging with exercise stress testing.

PubMed

Duvall, W Lane; Savino, John A; Levine, Elliot J; Hermann, Luke K; Croft, Lori B; Henzlova, Milena J

2015-02-01

Previous literature suggests that myocardial perfusion imaging (MPI) adds little to the prognosis of patients who exercise >10 metabolic equivalents (METs) during stress testing. With this in mind, we prospectively tested a provisional injection protocol in emergency department (ED) patients presenting for the evaluation of chest pain in which a patient would not receive an injection of radioisotope if adequate exercise was achieved without symptoms and a negative ECG response. All patients who presented to the ED over a 5-year period who were referred for stress testing as part of their ED evaluation were included. Patients considered for a provisional protocol were: exercise stress, age <65 years, no known coronary artery disease, and an interpretable rest ECG. Criteria for not injecting included a maximal predicted heart rate ≥85%, ≥10 METs of exercise, no anginal symptoms during stress, and no ECG changes. Groups were compared based on stress test results, all-cause and cardiac mortality, follow-up cardiac testing, subsequent revascularization, and cost. A total of 965 patients were eligible with 192 undergoing exercise-only and 773 having perfusion imaging. After 41.6 ± 19.6 months of follow-up, all-cause mortality was similar in the exercise-only versus the exercise plus imaging group (2.6% vs. 2.1%, p = 0.59). There were no cardiac deaths in the exercise-only group. At 1 year there was no difference in the number of repeat functional stress tests (1.6% vs. 2.1%, p = 0.43), fewer angiograms (0% vs. 4.0%, p = 0.002), and a significantly lower cost ($65 ± $332 vs $506 ± $1,991, p = 0.002; values are in US dollars) in the exercise-only group. The radiation exposure in the exercise plus imaging group was 8.4 ± 2.1 mSv. A provisional injection protocol has a very low mortality, few follow-up diagnostic tests, and lower cost compared to standard imaging protocols. If adopted it would decrease radiation exposure, save time and decrease health-care costs without jeopardizing prognosis.

Prevalence and prognostic value of exercise-induced ventricular arrhythmias.

PubMed

Partington, Sara; Myers, Jonathan; Cho, Shaun; Froelicher, Victor; Chun, Sung

2003-01-01

The purpose of this study was to determine the prevalence and prognostic significance of exercise-induced ventricular arrhythmias (EIVAs) in patients referred for exercise testing, considering the arrhythmic substrate and exercise-induced ischemia. EIVAs are frequently observed during exercise testing, but their prognostic significance is uncertain. The design of this study was a retrospective analysis of prospectively collected data, and it took place in 2 university-affiliated Veterans Affairs Medical Centers. Patients comprised 6213 consecutive males referred for exercise tests. We measured clinical exercise test responses and all-cause mortality after a mean follow-up of 6 +/- 4 years. EIVAs were defined as frequent premature ventricular contractions (PVCs) constituting >10% of all ventricular depolarizations during any 30 second electrocardiogram recording, or a run of > or =3 consecutive PVCs during exercise or recovery. A total of 1256 patients (20%) died during follow-up. EIVAs occurred in 503 patients (8%); the prevalence of EIVAs increased in older patients and in those with cardiopulmonary disease, resting PVCs, and ischemia during exercise. EIVAs were associated with mortality irrespective of the presence of cardiopulmonary disease or exercise-induced ischemia. In those without cardiopulmonary disease, mortality differed more so later in follow up than earlier. In those without resting PVCs, EIVAs were also predictive of mortality, but in those with resting PVCs, poorer prognosis was not worsened by the presence of EIVAs. Exercise induced ischemia does not affect the prognostic value of EIVAs, whereas the arrhythmic substrate does. EIVAs and resting PVCs are both independent predictors of mortality after consideration of other clinical and exercise-test variables. These findings are of limited clinical significance because of the modest change in risk and the lack of any established intervention. However, they explain some of the previous controversy and highlight the need to consider resting PVCs and follow-up duration in assessing the clinical implications of EIVAs.

Deconditioning-induced exercise responses as influenced by heat acclimation

NASA Technical Reports Server (NTRS)

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

1979-01-01

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

Comparison of forearm blood flow responses to incremental handgrip and cycle ergometer exercise: relative contribution of nitric oxide

PubMed Central

Green, Daniel J; Bilsborough, William; Naylor, Louise H; Reed, Chris; Wright, Jeremy; O'Driscoll, Gerry; Walsh, Jennifer H

2005-01-01

The contribution of endothelium-derived nitric oxide (NO) to exercise hyperaemia remains controversial. Disparate findings may, in part, be explained by different shear stress stimuli as a result of different types of exercise. We have directly compared forearm blood flow (FBF) responses to incremental handgrip and cycle ergometer exercise in 14 subjects (age ± s.e.m.) using a novel software system which calculates conduit artery blood flow continuously across the cardiac cycle by synchronising automated edge-detection and wall tracking of high resolution B-mode arterial ultrasound images and Doppler waveform envelope analysis. Monomethyl arginine (l-NMMA) was infused during repeat bouts of each incremental exercise test to assess the contribution of NO to hyperaemic responses. During handgrip, mean FBF increased with workload (P < 0.01) whereas FBF decreased at lower cycle workloads (P < 0.05), before increasing at 120 W (P < 0.001). Differences in these patterns of mean FBF response to different exercise modalities were due to the influence of retrograde diastolic flow during cycling, which had a relatively larger impact on mean flows at lower workloads. Retrograde diastolic flow was negligible during handgrip. Although mean FBF was lower in response to cycling than handgrip exercise, the impact of l–NMMA was significant during the cycle modality only (P < 0.05), possibly reflecting the importance of an oscillatory antegrade/retrograde flow pattern on shear stress-mediated release of NO from the endothelium. In conclusion, different types of exercise present different haemodynamic stimuli to the endothelium, which may result in differential effects of shear stress on the vasculature. PMID:15513940

The Effects of Caffeine Supplementation on Physiological Responses to Submaximal Exercise in Endurance-Trained Men.

PubMed

Glaister, Mark; Williams, Benjamin Henley; Muniz-Pumares, Daniel; Balsalobre-Fernández, Carlos; Foley, Paul

2016-01-01

The aim of this study was to evaluate the effects of caffeine on physiological responses to submaximal exercise, with a focus on blood lactate concentration ([BLa]). Using a randomised, single-blind, crossover design; 16 endurance-trained, male cyclists (age: 38 ± 8 years; height: 1.80 ± 0.05 m; body mass: 76.6 ± 7.8 kg; [Formula: see text]: 4.3 ± 0.6 L∙min-1) completed four trials on an electromagnetically-braked cycle ergometer. Each trial consisted of a six-stage incremental test (3 minute stages) followed by 30 minutes of passive recovery. One hour before trials 2-4, participants ingested a capsule containing 5 mg∙kg-1 of either caffeine or placebo (maltodextrin). Trials 2 and 3 were designed to evaluate the effects of caffeine on various physiological responses during exercise and recovery. In contrast, Trial 4 was designed to evaluate the effects of caffeine on [BLa] during passive recovery from an end-exercise concentration of 4 mmol∙L-1. Relative to placebo, caffeine increased [BLa] during exercise, independent of exercise intensity (mean difference: 0.33 ± 0.41 mmol∙L-1; 95% likely range: 0.11 to 0.55 mmol∙L-1), but did not affect the time-course of [BLa] during recovery (p = 0.604). Caffeine reduced ratings of perceived exertion (mean difference: 0.5 ± 0.7; 95% likely range: 0.1 to 0.9) and heart rate (mean difference: 3.6 ± 4.2 b∙min-1; 95% likely range: 1.3 to 5.8 b∙min-1) during exercise, with the effect on the latter dissipating as exercise intensity increased. Supplement × exercise intensity interactions were observed for respiratory exchange ratio (p = 0.004) and minute ventilation (p = 0.034). The results of the present study illustrate the clear, though often subtle, effects of caffeine on physiological responses to submaximal exercise. Researchers should be aware of these responses, particularly when evaluating the physiological effects of various experimental interventions.

The 894G>T endothelial nitric oxide synthase genetic polymorphism affects hemodynamic responses to mental stress performed before and after exercise.

PubMed

Rocha, Natália Galito; Neves, Fabricia Junqueira; Silva, Bruno Moreira; Sales, Allan Robson Kluser; Nóbrega, Antonio Claudio

2012-03-01

Nitric oxide is the primary mediator of vasodilation during mental stress. Since genetic polymorphisms in the nitric oxide synthase (eNOS) gene seem to impair the production of NO, this study aimed to evaluate the effect of an exercise bout on hemodynamic responses to mental stress in subjects with the 894G>T polymorphism of eNOS. Subjects without (wild-type group; n = 16) or with (polymorphic-type group; n = 19) the 894G>T polymorphism underwent a mental stress challenge before and after a maximal cardiopulmonary exercise test. Blood pressure was measured by auscultation and forearm blood flow by venous occlusion plethysmography. The groups were similar regarding anthropometric, metabolic, resting blood pressure and exercise variables. Before exercise, systolic blood pressure response during mental stress was higher in the polymorphic-type group (∆wild-type: 8.0 ± 2.0% vs. ∆polymorphic-type: 12.5 ± 1.8%, P = 0.01), while the increase in forearm vascular conductance was similar between the groups (∆wild-type 90.8 ± 26.4% vs. ∆polymorphic-type: 86.3 ± 24.1%, P = 0.44). After exercise, the systolic blood pressure at baseline and during mental stress was lower than before exercise in the whole group (P < 0.05), but the pressure response during mental stress was still higher in the polymorphic-type group (∆wild-type: 5.8 ± 1.5% vs. ∆polymorphic-type: 10.2 ± 1.4%, P = 0.01). The increase in forearm vascular conductance was inhibited only in the polymorphic-type group (∆before exercise 86.3 ± 24.1% vs. ∆after exercise: 41.5 ± 12.6%, P = 0.04). In conclusion, these results suggest the 894G>T eNOS polymorphism is associated with altered hemodynamic responses to mental stress both before and after a single bout of dynamic exercise with potential clinical implications.

Dispositional Mindfulness Predicts Adaptive Affective Responses to Health Messages and Increased Exercise Motivation

PubMed Central

O’Donnell, Matthew Brook; Strecher, Victor J.; Falk, Emily B.

2016-01-01

Feelings can shape how people respond to persuasive messages. In health communication, adaptive affective responses to potentially threating messages constitute one key to intervention success. The current study tested dispositional mindfulness, characterized by awareness of the present moment, as a predictor of adaptive affective responses to potentially threatening health messages and desirable subsequent health outcomes. Both general and discrete negative affective states (i.e., shame) were examined in relation to mindfulness and intervention success. Individuals (n=67) who reported less than 195 weekly minutes of exercise were recruited. At baseline, participants’ dispositional mindfulness and exercise outcomes were assessed, including self-reported exercise motivation and physical activity. A week later, all participants were presented with potentially threatening and self-relevant health messages encouraging physical activity and discouraging sedentary lifestyle, and their subsequent affective response and exercise motivation were assessed. Approximately one month later, changes in exercise motivation and physical activity were assessed again. In addition, participants’ level of daily physical activity was monitored by a wrist worn accelerometer throughout the entire duration of the study. Higher dispositional mindfulness predicted greater increases in exercise motivation one month after the intervention. Importantly, this effect was fully mediated by lower negative affect and shame specifically, in response to potentially threatening health messages among highly mindful individuals. Baseline mindfulness was also associated with increased self-reported vigorous activity, but not with daily physical activity as assessed by accelerometers. These findings suggest potential benefits of considering mindfulness as an active individual difference variable in theories of affective processing and health communication. PMID:28344683

Dispositional Mindfulness Predicts Adaptive Affective Responses to Health Messages and Increased Exercise Motivation.

PubMed

Kang, Yoona; O'Donnell, Matthew Brook; Strecher, Victor J; Falk, Emily B

2017-04-01

Feelings can shape how people respond to persuasive messages. In health communication, adaptive affective responses to potentially threating messages constitute one key to intervention success. The current study tested dispositional mindfulness, characterized by awareness of the present moment, as a predictor of adaptive affective responses to potentially threatening health messages and desirable subsequent health outcomes. Both general and discrete negative affective states (i.e., shame) were examined in relation to mindfulness and intervention success. Individuals (n=67) who reported less than 195 weekly minutes of exercise were recruited. At baseline, participants' dispositional mindfulness and exercise outcomes were assessed, including self-reported exercise motivation and physical activity. A week later, all participants were presented with potentially threatening and self-relevant health messages encouraging physical activity and discouraging sedentary lifestyle, and their subsequent affective response and exercise motivation were assessed. Approximately one month later, changes in exercise motivation and physical activity were assessed again. In addition, participants' level of daily physical activity was monitored by a wrist worn accelerometer throughout the entire duration of the study. Higher dispositional mindfulness predicted greater increases in exercise motivation one month after the intervention. Importantly, this effect was fully mediated by lower negative affect and shame specifically, in response to potentially threatening health messages among highly mindful individuals. Baseline mindfulness was also associated with increased self-reported vigorous activity, but not with daily physical activity as assessed by accelerometers. These findings suggest potential benefits of considering mindfulness as an active individual difference variable in theories of affective processing and health communication.

Repeated bouts of exhaustive exercise increase circulating cell free nuclear and mitochondrial DNA without development of tolerance in healthy men

PubMed Central

Stawski, Robert; Walczak, Konrad; Kosielski, Piotr; Meissner, Pawel; Budlewski, Tomasz; Padula, Gianluca; Nowak, Dariusz

2017-01-01

Objective Acute single strenuous exercise increases circulating cell free DNA (cf DNA). We tested whether three repeated bouts of exhaustive exercise induced the cf DNA response without development of tolerance in healthy men. Methods Eleven average-trained men (age 34.0±5.2 years, body mass index 26.2±3.1 kg/m2, maximal oxygen consumption—VO2max 49.6±4.5 ml/kg*min) performed three treadmill exercise tests to exhaustion at speed corresponding to 70% VO2max separated by 72 hours of resting. Blood was collected before and after each bout of exercise for determination of cell free nuclear and mitochondrial DNA (cf n-DNA, cf mt-DNA) by real-time PCR, selected markers of muscle damage, and blood cell count. Results Each bout induced the increase (p<0.05) in plasma cf n-DNA: from 3.4±1.4 to 38.5±27.5, from 4.1±3.3 to 48.5±26.2, and 3.1±1.6 to 53.8±39.9 ng/mL after the first, second, and third exercise, respectively. In a congruent way, cf mt-DNA rose significantly after the second (from 229±216 to 450±228*103 GE/mL) and third bout of exercise (from 173±120 to 462±314*103 GE/mL). Pre-exercise cf mt-DNA decreased (p<0.05) by 2-times (from 355±219 before the first bout to 173±120*103 GE/mL before the third bout) over the study period and were accompanied by significant increase in white blood cells, platelets, creatine kinase, creatinine and lactate after each bout. However, the exercise induced percentage increment of cf n-DNA was always many times higher than corresponding increments of the afore-mentioned markers at any occasion. Conclusions Repeated bouts of exhaustive exercise induced remarkable increase in circulating cf n-DNA without signs of tolerance development. Baseline cf mt-DNA decreased in response to series of strenuous exercise. Since percentage increments of cf n-DNA in response to exercise were many times higher than those observed for other markers, measurement of circulating cf n-DNA could be a sensitive tool for monitoring acute exercise effects in human body. PMID:28542490

Increased response of diastolic blood pressure to exercise in patients with coronary artery disease: an index of latent ventricular dysfunction?

PubMed Central

Paraskevaidis, I A; Kremastinos, D T; Kassimatis, A S; Karavolias, G K; Kordosis, G D; Kyriakides, Z S; Toutouzas, P K

1993-01-01

OBJECTIVE--To determine whether an abnormal response of diastolic blood pressure during treadmill exercise stress testing correlated with the number of obstructed vessels and with left ventricular systolic function in patients with coronary artery disease. DESIGN--Diastolic blood pressure was measured invasively during exercise stress testing and coronary angiograms and left ventriculograms were obtained at rest in patients with coronary artery disease. The abnormal (> or = 15 mm Hg) diastolic blood pressure response was compared with the number of obstructed coronary arteries and with left ventricular systolic function. SETTING--Two tertiary referral centres. PATIENTS--50 consecutive patients (mean age 57 years) with coronary artery disease. MAIN OUTCOME MEASURES--The increase in diastolic blood pressure during exercise and its correlation with the appearance and disappearance of ST segment deviation, resting left ventricular systolic function, and the number of obstructed coronary arteries. RESULTS--Group 1: 10 (20%) patients (three with one, four with two, and three with three vessel coronary artery disease) (mean (SD) age 54.7 (12) years) had an abnormal diastolic blood pressure response that appeared 1.2 (0.3) min before ST segment deviation and became normal 0.9 (0.3) min after the ST segment returned to normal. Group 2: 40 (80%) patients (12 with one, 16 with two, and 12 with three vessel coronary arteries disease) (aged 56.8 (8.2) years) had a normal diastolic blood pressure response to stress testing. The ejection fraction (46.3 (5)%) and cardiac index (2.6 (0.1) 1/min/m2) in group 1 were less than in group 2 (61.6 (4.2)% and 3.8 (0.3) 1/min/m2 respectively, p < or = 0.001). The end systolic volume was greater in group 1 than in group 2: 38.7 (0.7 ml/m2 v 28.2 (2.1) ml/m2, p < or = 0.001. CONCLUSION--In patients with coronary artery disease an abnormal increase in diastolic blood pressure during exercise stress testing correlated well with left ventricular systolic function at rest but not with the number of obstructed coronary arteries. The abnormal response of diastolic blood pressure probably reflects deterioration of myocardial function. Images PMID:8343317

Differential effects of aging and exercise on intra-abdominal adipose arteriolar function and blood flow regulation

PubMed Central

Davis, Robert T.; Stabley, John N.; Dominguez, James M.; Ramsey, Michael W.; McCullough, Danielle J.; Lesniewski, Lisa A.; Delp, Michael D.

2013-01-01

Adipose tissue (AT), which typically comprises an increased percentage of body mass with advancing age, receives a large proportion of resting cardiac output. During exercise, an old age-associated inability to increase vascular resistance within the intra-abdominal AT may compromise the ability of the cardiovascular system to redistribute blood flow to the active musculature, contributing to the decline in exercise capacity observed in this population. We tested the hypotheses that 1) there would be an elevated perfusion of AT during exercise with old age that was associated with diminished vasoconstrictor responses of adipose-resistance arteries, and 2) chronic exercise training would mitigate the age-associated alterations in AT blood flow and vascular function. Young (6 mo; n = 40) and old (24 mo; n = 28) male Fischer 344 rats were divided into young sedentary (YSed), old sedentary (OSed), young exercise trained (YET), or old exercise trained (OET) groups, where training consisted of 10-12 wk of treadmill exercise. In vivo blood flow at rest and during exercise and in vitro α-adrenergic and myogenic vasoconstrictor responses in resistance arteries from AT were measured in all groups. In response to exercise, there was a directionally opposite change in AT blood flow in the OSed group (∼150% increase) and YSed (∼55% decrease) vs. resting values. Both α-adrenergic and myogenic vasoconstriction were diminished in OSed vs. YSed AT-resistance arteries. Exercise training resulted in a similar AT hyperemic response between age groups during exercise (YET, 9.9 ± 0.5 ml·min−1·100−1 g; OET, 8.1 ± 0.9 ml·min−1·100−1 g) and was associated with enhanced myogenic and α-adrenergic vasoconstriction of AT-resistance arteries from the OET group relative to OSed. These results indicate that there is an inability to increase vascular resistance in AT during exercise with old age, due, in part, to a diminished vasoconstriction of AT arteries. Furthermore, the results indicate that exercise training can augment vasoconstriction of AT arteries and mitigate age-related alterations in the regulation of AT blood flow during exercise. PMID:23349454

Oxidative stress and inflammation: liver responses and adaptations to acute and regular exercise.

PubMed

Pillon Barcelos, Rômulo; Freire Royes, Luiz Fernando; Gonzalez-Gallego, Javier; Bresciani, Guilherme

2017-02-01

The liver is remarkably important during exercise outcomes due to its contribution to detoxification, synthesis, and release of biomolecules, and energy supply to the exercising muscles. Recently, liver has been also shown to play an important role in redox status and inflammatory modulation during exercise. However, while several studies have described the adaptations of skeletal muscles to acute and chronic exercise, hepatic changes are still scarcely investigated. Indeed, acute intense exercise challenges the liver with increased reactive oxygen species (ROS) and inflammation onset, whereas regular training induces hepatic antioxidant and anti-inflammatory improvements. Acute and regular exercise protocols in combination with antioxidant and anti-inflammatory supplementation have been also tested to verify hepatic adaptations to exercise. Although positive results have been reported in some acute models, several studies have shown an increased exercise-related stress upon liver. A similar trend has been observed during training: while synergistic effects of training and antioxidant/anti-inflammatory supplementations have been occasionally found, others reported a blunting of relevant adaptations to exercise, following the patterns described in skeletal muscles. This review discusses current data regarding liver responses and adaptation to acute and regular exercise protocols alone or combined with antioxidant and anti-inflammatory supplementation. The understanding of the mechanisms behind these modulations is of interest for both exercise-related health and performance outcomes.

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

Consensus on measurement properties and feasibility of performance tests for the exercise and sport sciences: a Delphi study.

PubMed

Robertson, Sam; Kremer, Peter; Aisbett, Brad; Tran, Jacqueline; Cerin, Ester

2017-12-01

Performance tests are used for multiple purposes in exercise and sport science. Ensuring that a test displays an appropriate level of measurement properties for use within a population is important to ensure confidence in test findings. The aim of this study was to obtain subject matter expert consensus on the measurement and feasibility properties that should be considered for performance tests used in the exercise and sport sciences and how these should be defined. This information was used to develop a checklist for broader dissemination. A two-round Delphi study was undertaken including 33 exercise scientists, academics and sport scientists. Participants were asked to rate the importance of a range of measurement properties relevant to performance tests in exercise and sport science. Responses were obtained in binary and Likert-scale formats, with consensus defined as achieving 67% agreement on each question. Consensus was reached on definitions and terminology for all items. Ten level 1 items (those that achieved consensus on all four questions) and nine level 2 items (those achieving consensus on ≥2 questions) were included. Both levels were included in the final checklist. The checklist developed from this study can be used to inform decision-making and test selection for practitioners and researchers in the exercise and sport sciences. This can facilitate knowledge sharing and performance comparisons across sub-disciplines, thereby improving existing field practice and research methodological quality.

The protective effects of acute cardiovascular exercise on the interference of procedural memory.

PubMed

Jo, J S; Chen, J; Riechman, S; Roig, M; Wright, D L

2018-04-10

Numerous studies have reported a positive impact of acute exercise for procedural skill memory. Previous work has revealed this effect, but these findings are confounded by a potential contribution of a night of sleep to the reported exercise-mediated reduction in interference. Thus, it remains unclear if exposure to a brief bout of exercise can provide protection to a newly acquired motor memory. The primary objective of the present study was to examine if a single bout of moderate-intensity cardiovascular exercise after practice of a novel motor sequence reduces the susceptibility to retroactive interference. To address this shortcoming, 17 individuals in a control condition practiced a novel motor sequence that was followed by test after a 6-h wake-filled interval. A separate group of 17 individuals experienced practice with an interfering motor sequence 45 min after practice with the original sequence and were then administered test trials 6 h later. One additional group of 12 participants was exposed to an acute bout of exercise immediately after practice with the original motor sequence but prior to practice with the interfering motor sequence and the subsequent test. In comparison with the control condition, increased response times were revealed during the 6-h test for the individuals that were exposed to interference. The introduction of an acute bout of exercise between the practice of the two motor sequences produced a reduction in interference from practice with the second task at the time of test, however, this effect was not statistically significant. These data reinforce the hypothesis that while there may be a contribution from exercise to post-practice consolidation of procedural skills which is independent of sleep, sleep may interact with exercise to strengthen the effects of the latter on procedural memory.

Feasibility of cardiopulmonary exercise testing and training using a robotics-assisted tilt table in dependent-ambulatory stroke patients.

PubMed

Saengsuwan, Jittima; Huber, Celine; Schreiber, Jonathan; Schuster-Amft, Corina; Nef, Tobias; Hunt, Kenneth J

2015-09-26

We evaluated the feasibility of an augmented robotics-assisted tilt table (RATT) for incremental cardiopulmonary exercise testing (CPET) and exercise training in dependent-ambulatory stroke patients. Stroke patients (Functional Ambulation Category ≤ 3) underwent familiarization, an incremental exercise test (IET) and a constant load test (CLT) on separate days. A RATT equipped with force sensors in the thigh cuffs, a work rate estimation algorithm and real-time visual feedback to guide the exercise work rate was used. Feasibility assessment considered technical feasibility, patient tolerability, and cardiopulmonary responsiveness. Eight patients (4 female) aged 58.3 ± 9.2 years (mean ± SD) were recruited and all completed the study. For IETs, peak oxygen uptake (V'O2peak), peak heart rate (HRpeak) and peak work rate (WRpeak) were 11.9 ± 4.0 ml/kg/min (45 % of predicted V'O2max), 117 ± 32 beats/min (72 % of predicted HRmax) and 22.5 ± 13.0 W, respectively. Peak ratings of perceived exertion (RPE) were on the range "hard" to "very hard". All 8 patients reached their limit of functional capacity in terms of either their cardiopulmonary or neuromuscular performance. A ventilatory threshold (VT) was identified in 7 patients and a respiratory compensation point (RCP) in 6 patients: mean V'O2 at VT and RCP was 8.9 and 10.7 ml/kg/min, respectively, which represent 75 % (VT) and 85 % (RCP) of mean V'O2peak. Incremental CPET provided sufficient information to satisfy the responsiveness criteria and identification of key outcomes in all 8 patients. For CLTs, mean steady-state V'O2 was 6.9 ml/kg/min (49 % of V'O2 reserve), mean HR was 90 beats/min (56 % of HRmax), RPEs were > 2, and all patients maintained the active work rate for 10 min: these values meet recommended intensity levels for bouts of training. The augmented RATT is deemed feasible for incremental cardiopulmonary exercise testing and exercise training in dependent-ambulatory stroke patients: the approach was found to be technically implementable, acceptable to the patients, and it showed substantial cardiopulmonary responsiveness. This work has clinical implications for patients with severe disability who otherwise are not able to be tested.

Heart Rate and VO[subscript 2] Responses to Cycle Ergometry in White and African American Men

ERIC Educational Resources Information Center

Vehrs, Pat R.; Fellingham, Gilbert W.

2006-01-01

The validity of estimates of peak oxygen consumption (VO[subscript 2]peak) using submaximal exercise tests may be compromised when the participants being tested are not similar to the participants used to develop the test. This study compared ethnic differences in the heart rate (HR) and oxygen consumption (VO[subscript 2]) responses to submaximal…

Acute dietary nitrate supplementation enhances compensatory vasodilation during hypoxic exercise in older adults.

PubMed

Casey, Darren P; Treichler, David P; Ganger, Charles T; Schneider, Aaron C; Ueda, Kenichi

2015-01-15

We have previously demonstrated that aging reduces the compensatory vasodilator response during hypoxic exercise due to blunted nitric oxide (NO) signaling. Recent evidence suggests that NO bioavailability can be augmented by dietary nitrate through the nitrate-nitrite pathway. Thus we tested the hypothesis that acute dietary nitrate supplementation increases the compensatory vasodilator response to hypoxic exercise, particularly in older adults. Thirteen young (25 ± 1 yr) and 12 older (64 ± 2 yr) adults performed rhythmic forearm exercise at 20% of maximum voluntary contraction during normoxia and hypoxia (∼80% O2 saturation); both before (control) and 3 h after beetroot juice (BR) consumption. Forearm vascular conductance (FVC; ml·min(-1)·100 mmHg(-1)) was calculated from forearm blood flow (ml/min) and blood pressure (mmHg). Compensatory vasodilation was defined as the relative increase in FVC due to hypoxic exercise (i.e., % increase compared with respective normoxic exercise trial). Plasma nitrite was determined from venous blood samples obtained before the control trials and each of the exercise trials (normoxia and hypoxia) after BR. Consumption of BR increased plasma nitrite in both young and older adults (P < 0.001). During the control condition, the compensatory vasodilator response to hypoxic exercise was attenuated in older compared with young adults (3.8 ± 1.7% vs. 14.2 ± 1.2%, P < 0.001). Following BR consumption, compensatory vasodilation did not change in young (13.7 ± 3.3%, P = 0.81) adults but was substantially augmented in older adults (11.4 ± 2.1%, P < 0.01). Our data suggest that acute dietary nitrate supplementation increases the compensatory vasodilator response to hypoxic exercise in older but not young adults. Copyright © 2015 the American Physiological Society.

Effects of γ-Aminobutyric Acid A Receptor Activation on Counterregulatory Responses to Subsequent Exercise in Individuals With Type 1 Diabetes

PubMed Central

Hedrington, Maka S.; Mikeladze, Maia; Tate, Donna B.; Younk, Lisa M.; Davis, Ian

2016-01-01

The effects of γ-aminobutyric acid (GABA) A receptor activation on physiologic responses during next-day exercise in type 1 diabetes are unknown. To test the hypothesis that GABA A activation with the benzodiazepine alprazolam would blunt counterregulatory responses during subsequent exercise, 29 (15 male, 14 female) individuals with type 1 diabetes (HbA1c 7.8 ± 1%) were studied during separate 2-day protocols. Day 1 consisted of morning and afternoon 2-h euglycemic or 2.9 mmol/L hypoglycemic clamps with or without 1 mg alprazolam given 30 min before each clamp. Day 2 consisted of a 90-min euglycemic cycling exercise at 50% VO2max. Tritiated glucose was used to measure glucose kinetics. Despite equivalent day 2 insulin (93 ± 6 pmol/L) and glucose levels (5.3 ± 0.1 mmol/L), plasma epinephrine, norepinephrine, glucagon, cortisol, and growth hormone responses were similarly reduced after alprazolam or day 1 hypoglycemia compared with euglycemic control. Endogenous glucose production, lipolysis (glycerol, nonesterified fatty acid), and glycogenolysis (lactate) were also reduced during day 2 exercise after day 1 GABA A activation. We conclude that activation of GABA A receptors with alprazolam can result in widespread neuroendocrine, autonomic nervous system, and metabolic counterregulatory failure during subsequent submaximal exercise and may increase the risk of exercise-associated hypoglycemia in individuals with type 1 diabetes. PMID:27217489

Effect of maternal exercises on biophysical fetal and maternal parameters: a transversal study

PubMed Central

dos Santos, Caroline Mombaque; dos Santos, Wendel Mombaque; Gallarreta, Francisco Maximiliano Pancich; Pigatto, Camila; Portela, Luiz Osório Cruz; de Morais, Edson Nunes

2016-01-01

ABSTRACT Objective To evaluate the acute effects of maternal and fetal hemodynamic responses in pregnant women submitted to fetal Doppler and an aerobic physical exercise test according to the degree of effort during the activity and the impact on the well-being. Methods Transversal study with low risk pregnant women, obtained by convenience sample with gestational age between 26 to 34 weeks. The participants carry out a progressive exercise test. Results After the exercise session, reduced resistance (p=0.02) and pulsatility indices (p=0.01) were identified in the umbilical artery; however, other Doppler parameters analyzed, in addition to cardiotocography and fetal biophysical profile did not achieve significant change. Maternal parameters obtained linear growth with activity, but it was not possible to establish a standard with the Borg scale, and oxygen saturation remained stable. Conclusion A short submaximal exercise had little effect on placental blood flow after exercise in pregnancies without complications, corroborating that healthy fetus maintains homeostasis even in situations that alter maternal hemodynamics. PMID:28076590

Operation Windshield and the simplification of emergency management.

PubMed

Andrews, Michael

2016-01-01

Large, complex, multi-stakeholder exercises are the culmination of years of gradual progression through a comprehensive training and exercise programme. Exercises intended to validate training, refine procedures and test processes initially tested in isolation are combined to ensure seamless response and coordination during actual crises. The challenges of integrating timely and accurate situational awareness from an array of sources, including response agencies, municipal departments, partner agencies and the public, on an ever-growing range of media platforms, increase information management complexity in emergencies. Considering that many municipal emergency operations centre roles are filled by staff whose day jobs have little to do with crisis management, there is a need to simplify emergency management and make it more intuitive. North Shore Emergency Management has accepted the challenge of making emergency management less onerous to occasional practitioners through a series of initiatives aimed to build competence and confidence by making processes easier to use as well as by introducing technical tools that can simplify processes and enhance efficiencies. These efforts culminated in the full-scale earthquake exercise, Operation Windshield, which preceded the 2015 Emergency Preparedness and Business Continuity Conference in Vancouver, British Columbia.

Stress reactivity to and recovery from a standardised exercise bout: a study of 31 runners practising relaxation techniques

PubMed Central

Solberg, E; Ingjer, F; Holen, A; Sundgot-Borgen, J; Nilsson, S; Holme, I

2000-01-01

Objective—To compare the efficacy in runners of two relaxation techniques with regard to exercise reactivity and recovery after exercise. Methods—Thirty one adult male runners were studied prospectively for six months in three groups practising either meditation (n = 11) or autogenic training (n = 11) or serving as controls (n = 10). Before and after the six months relaxation intervention, indicators of reactivity to exercise and metabolism after exercise (blood lactate concentration, heart rate (HR), and oxygen consumption (VO2)), were tested immediately after and 10 minutes after exercise. Resting HR was also assessed weekly at home during the trial. State anxiety was measured before and after the intervention. Results—After the relaxation training, blood lactate concentration after exercise was significantly (p<0.01) decreased in the meditation group compared with the control group. No difference was observed in lactate responses between the autogenic training group and the control group. There were no significant differences among the groups with regard to HR, VO2, or levels of anxiety. Conclusion—Meditation training may reduce the lactate response to a standardised exercise bout. Key Words: autogenic training; lactate; meditation; recovery; relaxation; psychology PMID:10953899

A maximal incremental effort alters tear osmolarity depending on the fitness level in military helicopter pilots.

PubMed

Vera, Jesús; Jiménez, Raimundo; Madinabeitia, Iker; Masiulis, Nerijus; Cárdenas, David

2017-10-01

Fitness level modulates the physiological responses to exercise for a variety of indices. While intense bouts of exercise have been demonstrated to increase tear osmolarity (Tosm), it is not known if fitness level can affect the Tosm response to acute exercise. This study aims to compare the effect of a maximal incremental test on Tosm between trained and untrained military helicopter pilots. Nineteen military helicopter pilots (ten trained and nine untrained) performed a maximal incremental test on a treadmill. A tear sample was collected before and after physical effort to determine the exercise-induced changes on Tosm. The Bayesian statistical analysis demonstrated that Tosm significantly increased from 303.72 ± 6.76 to 310.56 ± 8.80 mmol/L after performance of a maximal incremental test. However, while the untrained group showed an acute Tosm rise (12.33 mmol/L of increment), the trained group experienced a stable Tosm physical effort (1.45 mmol/L). There was a significant positive linear association between fat indices and Tosm changes (correlation coefficients [r] range: 0.77-0.89), whereas the Tosm changes displayed a negative relationship with the cardiorespiratory capacity (VO2 max; r = -0.75) and performance parameters (r = -0.75 for velocity, and r = -0.67 for time to exhaustion). The findings from this study provide evidence that fitness level is a major determinant of Tosm response to maximal incremental physical effort, showing a fairly linear association with several indices related to fitness level. High fitness level seems to be beneficial to avoid Tosm changes as consequence of intense exercise. Copyright © 2017 Elsevier Inc. All rights reserved.

Acute Immune-Inflammatory Responses to a Single Bout of Aerobic Exercise in Smokers; The Effect of Smoking History and Status

PubMed Central

Kastelein, Tegan Emma; Duffield, Rob; Marino, Frank E.

2015-01-01

This study examined the acute immune and inflammatory responses to exercise in smokers compared to non-smokers, and further, the effect of smoking history on these immune-inflammatory responses. Fifty-four recreationally active males who were either smokers (SM; n = 27) or non-smokers (NS; n = 27) were allocated into either young (YSM, YNS) or middle-aged groups (MSM, MNS) based on smoking status. Participants were matched for fitness and smoking habits and following familiarization and baseline testing, undertook an exercise protocol that involved 40 min of cycle ergometry at 50% of VO2peak. Venous blood was obtained pre- and post- (0 min, 1, and 4 h) exercise to measure circulating leukocytes and inflammatory markers interleukin (IL)-6, IL-1β, IL-1ra, and monocyte chemoattractant protein-1 (MCP-1). Compared to MNS, MSM showed elevated basal concentrations of MCP-1, which were increased with a longer smoking history (P < 0.05). In response to exercise, YSM demonstrated an amplified IL-6 response from immediately- to 1 h-post compared to YNS. Furthermore, IL-1ra in YSM was elevated above that of YNS across all time points (P < 0.05). The MSM group had higher IL-1β at baseline when compared to YSM, although IL-1ra was greater for YSM at baseline (P < 0.05). Finally, the post-exercise leukocyte response was greater in MSM compared to YSM and non-smokers (P < 0.05). In conclusion, smoker’s exhibit elevated MCP-1 and IL-1β that seem to be evident with a longer smoking history (~15 years). Furthermore, the differences in exercise-induced inflammatory responses noted in YSM may be indicative tobacco smoke exposure priming circulating leukocytes to amplify inflammatory responses. PMID:26779179

Exercise does not produce hypoalgesia when performed immediately after a painful stimulus.

PubMed

Gajsar, Hannah; Nahrwold, Katharina; Titze, Christina; Hasenbring, Monika I; Vaegter, Henrik B

2018-04-25

Exercise-induced hypoalgesia (EIH) and conditioned pain modulation (CPM) are assumed to reflect descending pain inhibition. Potential interactions between EIH and CPM may be important in the therapy of chronic pain, as reduced CPM and increased pain after exercise are frequently observed. This study compared the EIH response after CPM was activated using a cold pressor task with the EIH response after a control condition. Thirty-one participants (age: 27.7±9.8; 15 female) completed two sessions: a cold pressor task (CPT) session, i.e. testing EIH with preceding CPM activation induced using a 2 min CPT at approximately 2°C, and a control session, i.e. testing EIH after a control condition (2 min of quiet rest). EIH was induced using a 15 min bicycling exercise at a target heart rate corresponding to 75% VO2 max. Repeated measures ANOVAs on pressure pain thresholds (PPTs) at the hand, back and leg were used to determine the effects of exercise after the cold pressor test and control condition. Furthermore, correlations between CPM and EIH, in the CPT session as well as control session, were calculated at each assessment site. A significant time x condition interaction (F(1, 30)=43.61, p<0.001, partial η2=0.59), with Bonferroni-corrected post-hoc t-tests showed that PPTs increased after exercise in the control session (p<0.001), but not in the CPT session (p=0.125). Furthermore, there was a small positive correlation of EIH in the control session and CPM at the hand (r=0.37, p=0.043). There was a moderate negative correlation of EIH in the CPT session and CPM at the hand (r=-0.50, p=0.004), and smaller negative correlations at the back (r=-0.37, p=0.036) and at the leg (r=-0.35, p=0.054). Attenuated EIH after the CPM activation in comparison to a control condition suggests that EIH and CPM may share underlying pain inhibitory mechanisms on a systemic level. This assumption is further supported by the finding of small to moderate significant correlations between EIH and CPM at the hand. The attenuated EIH response furthermore suggests that these mechanisms are exhaustible, i.e. that its effects decline after a certain amount of inhibition. In patients with chronic pain, assessing the current capacity of the descending pain inhibitory system - as indicated by the CPM response - may aid to make better predictions about how patients will respond to exercise with respect to acute pain reduction.

Anterior cerebral blood velocity and end-tidal CO2 responses to exercise differ in children and adults.

PubMed

Ellis, Lindsay A; Ainslie, Philip N; Armstrong, Victoria A; Morris, Laura E; Simair, Ryan G; Sletten, Nathan R; Tallon, Christine M; McManus, Ali M

2017-06-01

Little is known about the response of the cerebrovasculature to acute exercise in children and how these responses might differ with adults. Therefore, we compared changes in middle cerebral artery blood velocity (MCAV mean ), end-tidal Pco 2 ([Formula: see text]), blood pressure, and minute ventilation (V̇e) in response to incremental exercise between children and adults. Thirteen children [age: 9 ± 1 (SD) yr] and thirteen sex-matched adults (age: 25 ± 4 yr) completed a maximal exercise test, during which MCAV mean , [Formula: see text], and V̇e were measured continuously. These variables were measured at rest, at exercise intensities specific to individual ventilatory thresholds, and at maximum. Although MCAV mean was higher at rest in children compared with adults, there were smaller increases in children (1-12%) compared with adults (12-25%) at all exercise intensities. There were alterations in [Formula: see text] with exercise intensity in an age-dependent manner [ F (2.5,54.5) = 7.983, P < 0.001; η 2 = 0.266], remaining stable in children with increasing exercise intensity (37-39 mmHg; P > 0.05) until hyperventilation-induced reductions following the respiratory compensation point. In adults, [Formula: see text] increased with exercise intensity (36-45 mmHg, P < 0.05) until the ventilatory threshold. From the ventilatory threshold to maximum, adults showed a greater hyperventilation-induced hypocapnia than children. These findings show that the relative increase in MCAV mean during exercise was attenuated in children compared with adults. There was also a weaker relationship between MCAV mean and [Formula: see text] during exercise in children, suggesting that cerebral perfusion may be regulated by different mechanisms during exercise in the child. NEW & NOTEWORTHY These findings provide the first direct evidence that exercise increases cerebral blood flow in children to a lesser extent than in adults. Changes in end-tidal CO 2 parallel changes in cerebral perfusion in adults but not in children, suggesting age-dependent regulatory mechanisms of cerebral blood flow during exercise. Copyright © 2017 the American Physiological Society.

Listening to motivational music while walking elicits more positive affective response in patients with cystic fibrosis.

PubMed

Calik-Kutukcu, Ebru; Saglam, Melda; Vardar-Yagli, Naciye; Cakmak, Aslihan; Inal-Ince, Deniz; Bozdemir-Ozel, Cemile; Sonbahar-Ulu, Hazal; Arikan, Hulya; Yalcin, Ebru; Karakaya, Jale

2016-05-01

The purpose of this study was to investigate the effects of motivational and relaxation music on affective responses during exercise in patients with cystic fibrosis (CF). Thirty-seven patients with CF performed the 6-min walk test (6MWT) under three experimental conditions: listening to no music, relaxation music, and motivational music. 6-min distance × body weight product (6MWORK) was calculated for each trial. Patients' affective responses during exercise was evaluated with Feeling Scale (FS). The motivational qualities of music were evaluated with the Brunel Music Rating Inventory-2 (BMRI-2). 6MWORK was significantly lower while listening to relaxation music compared to 6MWORK without music (p < 0.05). FS and BMRI-2 scores were significantly higher during 6MWT with motivational music than 6MWT with relaxation music (p < 0.05). Carefully selected motivational music can lead to positive affective response during exercise and increase the enjoyment of patients from exercises in CF. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effects of polymorphisms in beta1-adrenoceptor and alpha-subunit of G protein on heart rate and blood pressure during exercise test. The Finnish Cardiovascular Study.

PubMed

Nieminen, Tuomo; Lehtimäki, Terho; Laiho, Jarno; Rontu, Riikka; Niemelä, Kari; Kööbi, Tiit; Lehtinen, Rami; Viik, Jari; Turjanmaa, Väinö; Kähönen, Mika

2006-02-01

We tested whether the Arg389Gly and Ser49Gly polymorphisms of the beta1-adrenergic receptor gene ADRB1 and the T393C polymorphism of the G protein alpha-subunit gene GNAS1 modulate heart rate (HR) and blood pressure responses during an exercise stress test. The study population comprised 890 participants (563 men and 327 women, mean age 58.1 +/- 12.6 yr) of the Finnish Cardiovascular Study. Their HR, systolic (SAP), and diastolic arterial pressures (DAP) at rest, during exercise, and 4 min after the test were measured and analyzed by repeated-measurement ANOVA (RANOVA). Genotypes were detected by TaqMan 5' nuclease assay. In all subjects, and in men and women separately, the T393C of GNAS1 was the only polymorphism with genotype x time interaction in HR over the three study phases (P = 0.04, RANOVA). None of the polymorphisms presented genotype x time interaction in SAP or DAP responses (P > 0.10, RANOVA). In all subjects at rest, the Ser49Gly polymorphism of ADRB1 tended (P = 0.06, ANOVA) to differentiate HR. Arg389Gly polymorphism of ADRB1 affected maximal SAP during exercise (P = 0.04, ANOVA) and the change in SAP from rest to maximal (P = 0.03, ANOVA). Arg389 homozygotes, particularly men, were less likely to have ventricular extrasystoles during the exercise (odds ratio = 0.68, 95% confidence interval = 0.51-0.91, P = 0.009, and odds ratio = 0.60, 95% confidence interval = 0.42-0.86, P = 0.006, respectively) than did Gly389 carriers. In conclusion, polymorphisms examined appear to have modulatory effects on hemodynamics in a clinical exercise test setting. However, the effects in absolute numbers were minor and clinically possibly insignificant.

Sex differences in response to maximal eccentric exercise.

PubMed

Sewright, Kimberly A; Hubal, Monica J; Kearns, Amy; Holbrook, Mariko T; Clarkson, Priscilla M

2008-02-01

This study examined sex differences in strength loss, muscle soreness, and serum creatine kinase (CK) and myoglobin (Mb) after high-intensity eccentric exercise of the elbow flexors in a large group of men and women. One hundred participants (58 women, 42 men) performed 50 maximal eccentric contractions of the elbow flexor muscles of their nondominant arm. Maximum isometric voluntary contraction (MVC) was recorded at baseline, immediately after exercise, and at 0.5 (12-14 h), 3, 4, 7, and 10 d after exercise. Blood samples for serum CK activity and Mb were taken at baseline and at 4, 7, and 10 d after exercise. Soreness was evaluated at baseline and at 0.5, 3, 4, 7, and 10 d after exercise. Women experienced significantly greater relative strength loss immediately after exercise (-57.8% +/- 19.1) than men (-50.4% +/- 16.9%) (independent t-test; P < or = 0.05), and a greater percentage of women experienced more than 70% strength loss immediately after exercise compared with men (34.4% of women; 7.1% of men). Men exhibited a larger CK response compared with women (ANCOVA; P < or = 0.05), partly because there were more men who were high responders. There were no significant differences between the sexes for serum Mb or soreness measures. Generally, stronger relationships among CK, soreness, and strength-loss measures were found in men compared with women (r = 0.55-0.59 for men; r = 0.12-0.49 for women). In response to eccentric exercise, women experienced greater immediate strength loss than men and were more likely to be high responders for immediate strength loss; men experienced greater serum CK activity than women and were more likely to be high responders for increased serum CK. Although the explanation for high responders to eccentric exercise remains unknown, we have shown that there are sex-specific differences in CK and strength-loss response after eccentric exercise.

Cardiovascular mortality prediction in veterans with arm exercise vs pharmacologic myocardial perfusion imaging.

PubMed

Martin, Wade H; Xian, Hong; Chandiramani, Pooja; Bainter, Emily; Klein, Andrew J P

2015-08-01

No data exist comparing outcome prediction from arm exercise vs pharmacologic myocardial perfusion imaging (MPI) stress test variables in patients unable to perform treadmill exercise. In this retrospective study, 2,173 consecutive lower extremity disabled veterans aged 65.4 ± 11.0years (mean ± SD) underwent either pharmacologic MPI (1730 patients) or arm exercise stress tests (443 patients) with MPI (n = 253) or electrocardiography alone (n = 190) between 1997 and 2002. Cox multivariate regression models and reclassification analysis by integrated discrimination improvement (IDI) were used to characterize stress test and MPI predictors of cardiovascular mortality at ≥10-year follow-up after inclusion of significant demographic, clinical, and other variables. Cardiovascular death occurred in 561 pharmacologic MPI and 102 arm exercise participants. Multivariate-adjusted cardiovascular mortality was predicted by arm exercise resting metabolic equivalents (hazard ratio [HR] 0.52, 95% CI 0.39-0.69, P < .001), 1-minute heart rate recovery (HR 0.61, 95% CI 0.44-0.86, P < .001), and pharmacologic and arm exercise delta (peak-rest) heart rate (both P < .001). Only an abnormal arm exercise MPI prognosticated cardiovascular death by multivariate Cox analysis (HR 1.98, 95% CI 1.04-3.77, P < .05). Arm exercise MPI defect number, type, and size provided IDI over covariates for prediction of cardiovascular mortality (IDI = 0.074-0.097). Only pharmacologic defect size prognosticated cardiovascular mortality (IDI = 0.022). Arm exercise capacity, heart rate recovery, and pharmacologic and arm exercise heart rate responses are robust predictors of cardiovascular mortality. Arm exercise MPI results are equivalent and possibly superior to pharmacologic MPI for cardiovascular mortality prediction in patients unable to perform treadmill exercise. Published by Elsevier Inc.

Eryptosis and hemorheological responses to maximal exercise in athletes: Comparison between running and cycling.

PubMed

Nader, E; Guillot, N; Lavorel, L; Hancco, I; Fort, R; Stauffer, E; Renoux, C; Joly, P; Germain, M; Connes, P

2018-05-01

We compared the effects of cycling and running exercise on hemorheological and hematological properties, as well as eryptosis markers. Seven endurance-trained subjects randomly performed a progressive and maximal exercise test on a cycle ergometer and a treadmill. Blood was sampled at rest and at the end of the exercise to analyze hematological and blood rheological parameters including hematocrit (Hct), red blood cell (RBC) deformability, aggregation, and blood viscosity. Hemoglobin saturation (SpO2), blood lactate, and glucose levels were also monitored. Red blood cell oxidative stress, calcium content, and phosphatidylserine exposure were determined by flow cytometry to assess eryptosis level. Cycling exercise increased blood viscosity and RBC aggregation whereas it had no significant effect on RBC deformability. In contrast, blood viscosity remained unchanged and RBC deformability increased with running. The increase in Hct, lactate, and glucose concentrations and the loss of weight at the end of exercise were not different between running and cycling. Eryptosis markers were not affected by exercise. A significant drop in SpO2 was noted during running but not during cycling. Our study showed that a progressive and maximal exercise test conducted on a cycle ergometer increased blood viscosity while the same test conducted on a treadmill did not change this parameter because of different RBC rheological behavior between the 2 tests. We also demonstrated that a short maximal exercise does not alter RBC physiology in trained athletes. We suspect that exercise-induced hypoxemia occurring during running could be at the origin of the RBC rheological behavior differences with cycling. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Cardiovascular responses during orthostasis - Effect of an increase in maximal O2 uptake

NASA Technical Reports Server (NTRS)

Convertino, V. A.; Montgomery, L. D.; Greenleaf, J. E.

1984-01-01

A study is described which tests the hypothesis that changes in aerobic activity (increases in maximum oxygen uptake) will reduce the effectiveness of cardiovascular reflexes to regulate blood pressure during orthostasis. The hypothesis was tested by measuring heart rate, blood pressure and blood volume responses in eight healthy male subjects before and after an eight-day endurance regimen. The results of the study suggest that the physiologic responses to orthostasis are dependent upon the rate of plasma volume loss and pooling, and are associated with training-induced hypervolemia. It is indicated that endurance type exercise training enhances cardiovascular adjustments during tilt. The implications of these results for the use of exercise training as a countermeasure and/or therapeutic method for the prevention of cardiovascular instability during orthostatic stress are discussed.

High-Intensity Exercise as a Dishabituating Stimulus Restores Counterregulatory Responses in Recurrently Hypoglycemic Rodents.

PubMed

McNeilly, Alison D; Gallagher, Jennifer R; Huang, Jeffrey T-J; Ashford, Michael L J; McCrimmon, Rory J

2017-06-01

Hypoglycemia is a major adverse effect of insulin therapy for people with type 1 diabetes (T1D). Profound defects in the normal counterregulatory response to hypoglycemia explain the frequency of hypoglycemia occurrence in T1D. Defective counterregulation results to a large extent from prior exposure to hypoglycemia per se, leading to a condition called impaired awareness of hypoglycemia (IAH), the cause of which is unknown. In the current study, we investigate the hypothesis that IAH develops through a special type of adaptive memory referred to as habituation. To test this hypothesis, we used a novel intense stimulus (high-intensity exercise) to demonstrate two classic features of a habituated response, namely dishabituation and response recovery. We demonstrate that after recurrent hypoglycemia the introduction of a novel dishabituating stimulus (a single burst of high-intensity exercise) in male Sprague-Dawley rats restores the defective hypoglycemia counterregulatory response. In addition, the rats showed an enhanced response to the novel stimulus (response recovery). We make the further observation using proteomic analysis of hypothalamic extracts that high-intensity exercise in recurrently hypoglycemic rats increases levels of a number of proteins linked with brain-derived neurotrophic factor signaling. These findings may lead to novel therapeutic approaches for individuals with T1D and IAH. © 2017 by the American Diabetes Association.

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.

Saxagliptin Restores Vascular Mitochondrial Exercise Response in the Goto-Kakizaki Rat

PubMed Central

Keller, Amy C.; Knaub, Leslie A.; Miller, Matthew W.; Birdsey, Nicholas; Klemm, Dwight J.

2015-01-01

Abstract: Cardiovascular disease risk and all-cause mortality are largely predicted by physical fitness. Exercise stimulates vascular mitochondrial biogenesis through endothelial nitric oxide synthase (eNOS), sirtuins, and PPARγ coactivator 1α (PGC-1α), a response absent in diabetes and hypertension. We hypothesized that an agent regulating eNOS in the context of diabetes could reconstitute exercise-mediated signaling to mitochondrial biogenesis. Glucagon-like peptide 1 (GLP-1) stimulates eNOS and blood flow; we used saxagliptin, an inhibitor of GLP-1 degradation, to test whether vascular mitochondrial adaptation to exercise in diabetes could be restored. Goto-Kakizaki (GK) rats, a nonobese, type 2 diabetes model, and Wistar controls were exposed to an 8-day exercise intervention with or without saxagliptin (10 mg·kg−1·d−1). We evaluated the impact of exercise and saxagliptin on mitochondrial proteins and signaling pathways in aorta. Mitochondrial protein expression increased with exercise in the Wistar aorta and decreased or remained unchanged in the GK animals. GK rats treated with saxagliptin plus exercise showed increased expression of mitochondrial complexes, cytochrome c, eNOS, nNOS, PGC-1α, and UCP3 proteins. Notably, a 3-week saxagliptin plus exercise intervention significantly increased running time in the GK rats. These data suggest that saxagliptin restores vascular mitochondrial adaptation to exercise in a diabetic rodent model and may augment the impact of exercise on the vasculature. PMID:25264749

Saxagliptin restores vascular mitochondrial exercise response in the Goto-Kakizaki rat.

PubMed

Keller, Amy C; Knaub, Leslie A; Miller, Matthew W; Birdsey, Nicholas; Klemm, Dwight J; Reusch, Jane E B

2015-02-01

Cardiovascular disease risk and all-cause mortality are largely predicted by physical fitness. Exercise stimulates vascular mitochondrial biogenesis through endothelial nitric oxide synthase (eNOS), sirtuins, and PPARγ coactivator 1α (PGC-1α), a response absent in diabetes and hypertension. We hypothesized that an agent regulating eNOS in the context of diabetes could reconstitute exercise-mediated signaling to mitochondrial biogenesis. Glucagon-like peptide 1 (GLP-1) stimulates eNOS and blood flow; we used saxagliptin, an inhibitor of GLP-1 degradation, to test whether vascular mitochondrial adaptation to exercise in diabetes could be restored. Goto-Kakizaki (GK) rats, a nonobese, type 2 diabetes model, and Wistar controls were exposed to an 8-day exercise intervention with or without saxagliptin (10 mg·kg·d). We evaluated the impact of exercise and saxagliptin on mitochondrial proteins and signaling pathways in aorta. Mitochondrial protein expression increased with exercise in the Wistar aorta and decreased or remained unchanged in the GK animals. GK rats treated with saxagliptin plus exercise showed increased expression of mitochondrial complexes, cytochrome c, eNOS, nNOS, PGC-1α, and UCP3 proteins. Notably, a 3-week saxagliptin plus exercise intervention significantly increased running time in the GK rats. These data suggest that saxagliptin restores vascular mitochondrial adaptation to exercise in a diabetic rodent model and may augment the impact of exercise on the vasculature.

Comparison of standardbred trotters exercising on a treadmill and a race track with identical draught resistances.

PubMed

Gottlieb-Vedi, M; Lindholm, A

1997-05-17

The responses in heart rate, plasma lactate and rectal temperature of standardbred trotters to draught loaded interval exercise on a treadmill and a race track were studied. The horses were exercised with incrementally increasing trotting speeds for two-minute intervals with draught loads of 10, 20 and 30 kilopond (kp) in three different tests. Each trotting interval was followed by two-minute periods at a walk without a draught load. Measurements of heart rate and plasma lactate were made at the end of each interval and the rectal temperature was taken at the end of the exercise. The heart rate and plasma lactate levels were significantly lower on the treadmill than on the track in the tests with 10 kp, but no significant differences were found between the treadmill and track exercise tests with the heavier draught resistances. No differences were observed in rectal temperature between treadmill and track conditions. From these findings it was concluded that the workload was significantly greater on the race track compared to the treadmill when the draught resistance was low (10 kp). Although the workload increased on both the race track and the treadmill as draught resistance increased, at the heavier draught resistances track exercise was no longer more demanding than exercise on the treadmill.

Development and Validation of the Adolescent Psychological Need Support in Exercise Questionnaire.

PubMed

Emm-Collison, Lydia G; Standage, Martyn; Gillison, Fiona B

2016-10-01

Grounded within self-determination theory (SDT; Deci & Ryan, 2000; Ryan & Deci, in press), three studies were conducted to develop and psychometrically test a measure of adolescents' perceptions of psychological need support for exercise (viz., for autonomy, competence, and relatedness): the Adolescent Psychological Need Support in Exercise Questionnaire (APNSEQ). In Study 1, 34 items were developed in collaboration with an expert panel. Through categorical confirmatory factor analysis and item response theory, responses from 433 adolescents were used to identify the best fitting and performing items in Study 2. Here, a three-factor nine-item measure showed good fit to the data. In Study 3, responses from an independent sample of 373 adolescents provided further evidence for the nine-item solution as well as for internal consistency, criterion validity, and invariance across gender and social agent (friends, family, and physical education teacher). The APNSEQ was supported as a measure of adolescents' perceptions of psychological need support within the context of exercise.

Exercise training improves hemodynamic recovery to isometric exercise in obese men with type 2 diabetes but not in obese women.

PubMed

Kanaley, Jill A; Goulopoulou, Styliani; Franklin, Ruth; Baynard, Tracy; Carhart, Robert L; Weinstock, Ruth S; Fernhall, Bo

2012-12-01

Women with type 2 diabetes (T2D) show greater rates of mortality due to ischemic heart disease than men with T2D. We aimed to examine cardiovascular and autonomic function responses to isometric handgrip (IHG) exercise between men and women with T2D, before and after an exercise training program. Hemodynamic responses were measured in 22 men and women with T2D during and following a 3-min IHG test, and before and after 16 wks of aerobic exercise training. Women had a smaller decrease in mean arterial pressure (MAP) and systolic blood pressure (BP) during recovery from IHG (ΔMAP(REC)) than men pre- and post-training (P<0.05). Men showed a greater reduction in diastolic BP during recovery from IHG (P<0.05), and exercise training improved this response in men but not in women (men, pre-training: -13.9±1.8, post-training: -20.5±5.3 mmHg vs. women, pre-training: -10.7±1.7, post-training: -4.1±4.9 mmHg; P<0.05). Men had a greater reduction in sympathetic modulation of vasomotor tone (P<0.05), as estimated by blood pressure variability, following IHG. This response was accentuated after training, while this training effect was not seen in women. Post-training ΔMAP(REC) was correlated with recovery of low frequency component of the BP spectrum (ΔLF(SBPrec), r=0.52, P<0.05). Differences in BP recovery immediately following IHG may be attributed to gender differences in cardiovascular autonomic modulation. An improvement in these responses occurs following aerobic exercise training in obese men, but not in obese women with T2D which reflects a better adaptive autonomic response to exercise training. Copyright © 2012 Elsevier Inc. All rights reserved.

Exaggerated Exercise Blood Pressure Response and Future Cardiovascular Disease.

PubMed

Tzemos, Nikolaos; Lim, Pitt O; Mackenzie, Isla S; MacDonald, Thomas M

2015-11-01

Exaggerated blood pressure (BP) response to exercise predicts future hypertension. However, there is considerable lack of understanding regarding the mechanism of how this abnormal response is generated, and how it relates to the future establishment of cardiovascular disease. The authors studied 82 healthy male volunteers without cardiovascular risk factors. The participants were categorized into two age-matched groups depending on their exercise systolic BP (ExSBP) rise after 3 minutes of exercise using a submaximal step test: exaggerated ExSBP group (hyper-responders [peak SBP ≥ 180 mm Hg]) and low ExSBP responder group (hypo-responders [peak SBP <180 mm Hg]). Forearm venous occlusion plethysmography and intra-arterial infusions of acetylcholine (ACh), N(G)-monomethyl-L-arginine (L-NMMA), sodium nitroprusside (SNP), and norepinephrine (NE) were used to assess vascular reactivity. Proximal aortic compliance was assessed with ultrasound, and neurohormonal blood sampling was performed at rest and during peak exercise. The hyper-responder group exhibited a significantly lower increase in forearm blood flow (FBF) with ACh compared with the hypo-responder group (ΔFBF 215% [14] vs 332.3% [28], mean [standard error of the mean]; P<.001), as well as decreased proximal aortic compliance. The vasoconstrictive response to L-NMMA was significantly impaired in the hyper-responder group in comparison to the hypo-responder group (ΔFBF -40.2% [1.6] vs -50.2% [2.6]; P<.05). In contrast, the vascular response to SNP and NE were comparable in both groups. Peak exercise plasma angiotensin II levels were significantly higher in the hyper-responder group (31 [1] vs 23 [2] pg/mL, P=.01). An exaggerated BP response to exercise is related to endothelial dysfunction, decreased proximal aortic compliance, and increased exercise-related neurohormonal activation, the constellation of which may explain future cardiovascular disease. © 2015 Wiley Periodicals, Inc.

Intrathecal fentanyl abolishes the exaggerated blood pressure response to cycling in hypertensive men

PubMed Central

Barbosa, Thales C.; Vianna, Lauro C.; Fernandes, Igor A.; Prodel, Eliza; Rocha, Helena N. M.; Garcia, Vinicius P.; Rocha, Natalia G.; Secher, Niels H.

2016-01-01

Key points The increase in blood pressure observed during physical activities is exaggerated in patients with hypertension, exposing them to a higher cardiovascular risk.Neural signals from the skeletal muscles appear to be overactive, resulting in this abnormal response in hypertensive patients.In the present study, we tested whether the attenuation of these neural signals in hypertensive patients could normalize their abnormal increase in blood pressure during physical activity.Attenuation of the neural signals from the leg muscles with intrathecal fentanyl injection reduced the blood pressure of hypertensive men during cycling exercise to a level comparable to that of normotensive men.Skeletal muscle afferent overactivity causes the abnormal cardiovascular response to exercise and was reverted in this experimental model, appearing as potential target for treatment. Abstract Hypertensive patients present an exaggerated increase in blood pressure and an elevated cardiovascular risk during exercise. Although controversial, human studies suggest that group III and IV skeletal muscle afferents might contribute to this abnormal response. In the present study, we investigated whether attenuation of the group III and IV muscle afferent signal of hypertensive men eliminates the exaggerated increase in blood pressure occurring during exercise. Eight hypertensive men performed two sessions of 5 min of cycling exercise at 40 W. Between sessions, the subjects were provided with a lumbar intrathecal injection of fentanyl, a μ‐opioid receptor agonist, aiming to attenuate the central projection of opioid‐sensitive group III and IV muscle afferent nerves. The cardiovascular response to exercise of these subjects was compared with that of six normotensive men. During cycling, the hypertensive group demonstrated an exaggerated increase in blood pressure compared to the normotensive group (mean ± SEM: +17 ± 3 vs. +8 ± 1 mmHg, respectively; P < 0.05), whereas the increase in heart rate, stroke volume, cardiac output and vascular conductance was similar (P > 0.05). Fentanyl inhibited the blood pressure response to exercise in the hypertensive group (+11 ± 2 mmHg) to a level comparable to that of the normotensive group (P > 0.05). Moreover, fentanyl increased the responses of vascular conductance and stroke volume to exercise (P < 0.05), whereas the heart rate response was attenuated (P < 0.05) and the cardiac output response was maintained (P > 0.05). The results of the present study show that attenuation of the exercise pressor reflex normalizes the blood pressure response to cycling exercise in hypertensive individuals. PMID:26659384

Peripheral vascular reactivity and serum BDNF responses to aerobic training are impaired by the BDNF Val66Met polymorphism.

PubMed

Lemos, José R; Alves, Cleber R; de Souza, Sílvia B C; Marsiglia, Julia D C; Silva, Michelle S M; Pereira, Alexandre C; Teixeira, Antônio L; Vieira, Erica L M; Krieger, José E; Negrão, Carlos E; Alves, Guilherme B; de Oliveira, Edilamar M; Bolani, Wladimir; Dias, Rodrigo G; Trombetta, Ivani C

2016-02-01

Besides neuronal plasticity, the neurotrophin brain-derived neurotrophic factor (BDNF) is also important in vascular function. The BDNF has been associated with angiogenesis through its specific receptor tropomyosin-related kinase B (TrkB). Additionally, Val66Met polymorphism decreases activity-induced BDNF. Since BDNF and TrkB are expressed in vascular endothelial cells and aerobic exercise training can increase serum BDNF, this study aimed to test the hypotheses: 1) Serum BDNF levels modulate peripheral blood flow; 2) The Val66Met BDNF polymorphism impairs exercise training-induced vasodilation. We genotyped 304 healthy male volunteers (Val66Val, n = 221; Val66Met, n = 83) who underwent intense aerobic exercise training on a running track three times/wk for 4 mo. We evaluated pre- and post-exercise training serum BDNF and proBDNF concentration, heart rate (HR), mean blood pressure (MBP), forearm blood flow (FBF), and forearm vascular resistance (FVR). In the pre-exercise training, BDNF, proBDNF, BDNF/proBDNF ratio, FBF, and FVR were similar between genotypes. After exercise training, functional capacity (V̇o2 peak) increased and HR decreased similarly in both groups. Val66Val, but not Val66Met, increased BDNF (interaction, P = 0.04) and BDNF/proBDNF ratio (interaction, P < 0.001). Interestingly, FBF (interaction, P = 0.04) and the FVR (interaction, P = 0.01) responses during handgrip exercise (HG) improved in Val66Val compared with Val66Met, even with similar responses of HR and MBP. There were association between BDNF/proBDNF ratio and FBF (r = 0.64, P < 0.001) and FVR (r = -0.58, P < 0.001) during HG exercise. These results show that peripheral vascular reactivity and serum BDNF responses to exercise training are impaired by the BDNF Val66Met polymorphism and such responsiveness is associated with serum BDNF concentrations in healthy subjects. Copyright © 2016 the American Physiological Society.

Where does HIT fit? An examination of the affective response to high-intensity intervals in comparison to continuous moderate- and continuous vigorous-intensity exercise in the exercise intensity-affect continuum.

PubMed

Jung, Mary E; Bourne, Jessica E; Little, Jonathan P

2014-01-01

Affect experienced during an exercise session is purported to predict future exercise behaviour. Compared to continuous moderate-intensity exercise (CMI), the affective response to continuous vigorous-intensity exercise (CVI) has consistently been shown to be more aversive. The affective response, and overall tolerability to high-intensity interval training (HIT), is less studied. To date, there has yet to be a comparison between HIT, CVI, and CMI. The purpose of this study was to compare the tolerability and affective responses during HIT to CVI and CMI. This study utilized a repeated measures, randomized, counter-balanced design. Forty-four participants visited the laboratory on four occasions. Baseline fitness testing was conducted to establish peak power output in Watts (W peak). Three subsequent visits involved a single bout of a) HIT, corresponding to 1-minute at ∼ 100% W peak and 1-minute at ∼ 20% W peak for 20 minutes, b) CMI, corresponding to ∼ 40% W peak for 40 minutes, and c) CVI, corresponding to ∼ 80% W peak for 20 minutes. The order of the sessions was randomized. Affective responses were measured before, during and after each session. Task self-efficacy, intentions, enjoyment and preference were measured after sessions. Participants reported greater enjoyment of HIT as compared to CMI and CVI, with over 50% of participants reporting a preference to engage in HIT as opposed to either CMI or CVI. HIT was considered more pleasurable than CVI after exercise, but less pleasurable than CMI at these times. Despite this participants reported being just as confident to engage in HIT as they were CMI, but less confident to engage in CVI. This study highlights the utility of HIT in inactive individuals, and suggests that it may be a viable alternative to traditionally prescribed continuous modalities of exercise for promoting self-efficacy and enjoyment of exercise.

Where Does HIT Fit? An Examination of the Affective Response to High-Intensity Intervals in Comparison to Continuous Moderate- and Continuous Vigorous-Intensity Exercise in the Exercise Intensity-Affect Continuum

PubMed Central

Jung, Mary E.; Bourne, Jessica E.; Little, Jonathan P.

2014-01-01

Affect experienced during an exercise session is purported to predict future exercise behaviour. Compared to continuous moderate-intensity exercise (CMI), the affective response to continuous vigorous-intensity exercise (CVI) has consistently been shown to be more aversive. The affective response, and overall tolerability to high-intensity interval training (HIT), is less studied. To date, there has yet to be a comparison between HIT, CVI, and CMI. The purpose of this study was to compare the tolerability and affective responses during HIT to CVI and CMI. This study utilized a repeated measures, randomized, counter-balanced design. Forty-four participants visited the laboratory on four occasions. Baseline fitness testing was conducted to establish peak power output in Watts (Wpeak). Three subsequent visits involved a single bout of a) HIT, corresponding to 1-minute at ∼100% Wpeak and 1-minute at ∼20% Wpeak for 20 minutes, b) CMI, corresponding to ∼40% Wpeak for 40 minutes, and c) CVI, corresponding to ∼80% Wpeak for 20 minutes. The order of the sessions was randomized. Affective responses were measured before, during and after each session. Task self-efficacy, intentions, enjoyment and preference were measured after sessions. Participants reported greater enjoyment of HIT as compared to CMI and CVI, with over 50% of participants reporting a preference to engage in HIT as opposed to either CMI or CVI. HIT was considered more pleasurable than CVI after exercise, but less pleasurable than CMI at these times. Despite this participants reported being just as confident to engage in HIT as they were CMI, but less confident to engage in CVI. This study highlights the utility of HIT in inactive individuals, and suggests that it may be a viable alternative to traditionally prescribed continuous modalities of exercise for promoting self-efficacy and enjoyment of exercise. PMID:25486273

Epicardial fat gene expression after aerobic exercise training in pigs with coronary atherosclerosis: relationship to visceral and subcutaneous fat.

PubMed

Company, Joseph M; Booth, Frank W; Laughlin, M Harold; Arce-Esquivel, Arturo A; Sacks, Harold S; Bahouth, Suleiman W; Fain, John N

2010-12-01

Epicardial adipose tissue (EAT) is contiguous with coronary arteries and myocardium and potentially may play a role in coronary atherosclerosis (CAD). Exercise is known to improve cardiovascular disease risk factors. The purpose of this study was to investigate the effect of aerobic exercise training on the expression of 18 genes, measured by RT-PCR and selected for their role in chronic inflammation, oxidative stress, and adipocyte metabolism, in peri-coronary epicardial (cEAT), peri-myocardial epicardial (mEAT), visceral abdominal (VAT), and subcutaneous (SAT) adipose tissues from a castrate male pig model of familial hypercholesterolemia with CAD. We tested the hypothesis that aerobic exercise training for 16 wk would reduce the inflammatory profile of mRNAs in both components of EAT and VAT but would have little effect on SAT. Exercise increased mEAT and total heart weights. EAT and heart weights were directly correlated. Compared with sedentary pigs matched for body weight to exercised animals, aerobic exercise training reduced the inflammatory response in mEAT but not cEAT, had no effect on inflammatory genes but preferentially decreased expression of adiponectin and other adipocyte-specific genes in VAT, and had no effect in SAT except that IL-6 mRNA went down and VEGFa mRNA went up. We conclude that 1) EAT is not homogeneous in its inflammatory response to aerobic exercise training, 2) cEAT around CAD remains proinflammatory after chronic exercise, 3) cEAT and VAT share similar inflammatory expression profiles but different metabolic mRNA responses to exercise, and 4) gene expression in SAT cannot be extrapolated to VAT and heart adipose tissues in exercise intervention studies.

Loss of capacity to recover from acidosis on repeat exercise in chronic fatigue syndrome: a case-control study.

PubMed

Jones, David E J; Hollingsworth, Kieren G; Jakovljevic, Djordje G; Fattakhova, Gulnar; Pairman, Jessie; Blamire, Andrew M; Trenell, Michael I; Newton, Julia L

2012-02-01

Chronic fatigue syndrome (CFS) patients frequently describe difficulties with repeat exercise. Here, we explore muscle bioenergetic function in response to three bouts of exercise. A total of 18 CFS (CDC 1994) patients and 12 sedentary controls underwent assessment of maximal voluntary contraction (MVC), repeat exercise with magnetic resonance spectroscopy and cardio-respiratory fitness test to determine anaerobic threshold. Chronic fatigue syndrome patients undertaking MVC fell into two distinct groups: 8 (45%) showed normal PCr depletion in response to exercise at 35% of MVC (PCr depletion >33%; lower 95% CI for controls); 10 CFS patients had low PCr depletion (generating abnormally low MVC values). The CFS whole group exhibited significantly reduced anaerobic threshold, heart rate, VO(2) , VO(2) peak and peak work compared to controls. Resting muscle pH was similar in controls and both CFS patient groups. However, the CFS group achieving normal PCr depletion values showed increased intramuscular acidosis compared to controls after similar work after each of the three exercise periods with no apparent reduction in acidosis with repeat exercise of the type reported in normal subjects. This CFS group also exhibited significant prolongation (almost 4-fold) of the time taken for pH to recover to baseline. When exercising to comparable levels to normal controls, CFS patients exhibit profound abnormality in bioenergetic function and response to it. Although exercise intervention is the logical treatment for patients showing acidosis, any trial must exclude subjects who do not initiate exercise as they will not benefit. This potentially explains previous mixed results in CFS exercise trials. © 2011 The Authors. European Journal of Clinical Investigation © 2011 Stichting European Society for Clinical Investigation Journal Foundation.

Epicardial fat gene expression after aerobic exercise training in pigs with coronary atherosclerosis: relationship to visceral and subcutaneous fat

PubMed Central

Booth, Frank W.; Laughlin, M. Harold; Arce-Esquivel, Arturo A.; Sacks, Harold S.; Bahouth, Suleiman W.; Fain, John N.

2010-01-01

Epicardial adipose tissue (EAT) is contiguous with coronary arteries and myocardium and potentially may play a role in coronary atherosclerosis (CAD). Exercise is known to improve cardiovascular disease risk factors. The purpose of this study was to investigate the effect of aerobic exercise training on the expression of 18 genes, measured by RT-PCR and selected for their role in chronic inflammation, oxidative stress, and adipocyte metabolism, in peri-coronary epicardial (cEAT), peri-myocardial epicardial (mEAT), visceral abdominal (VAT), and subcutaneous (SAT) adipose tissues from a castrate male pig model of familial hypercholesterolemia with CAD. We tested the hypothesis that aerobic exercise training for 16 wk would reduce the inflammatory profile of mRNAs in both components of EAT and VAT but would have little effect on SAT. Exercise increased mEAT and total heart weights. EAT and heart weights were directly correlated. Compared with sedentary pigs matched for body weight to exercised animals, aerobic exercise training reduced the inflammatory response in mEAT but not cEAT, had no effect on inflammatory genes but preferentially decreased expression of adiponectin and other adipocyte-specific genes in VAT, and had no effect in SAT except that IL-6 mRNA went down and VEGFa mRNA went up. We conclude that 1) EAT is not homogeneous in its inflammatory response to aerobic exercise training, 2) cEAT around CAD remains proinflammatory after chronic exercise, 3) cEAT and VAT share similar inflammatory expression profiles but different metabolic mRNA responses to exercise, and 4) gene expression in SAT cannot be extrapolated to VAT and heart adipose tissues in exercise intervention studies. PMID:20947714

Thermoregulation During Spaceflight

NASA Technical Reports Server (NTRS)

Greenleaf, John E.; Fortney, Suzanne M.

1992-01-01

The purpose of this flight proposal is to investigate human thermoregulatory parameters during exercise in microgravity. The hypothesis to be tested is that microgravity-adopted astronauts will exhibit accentuated increases in their core temperature (excess hyperthermia) during exercise because of altered heat loss responses due to reduced sweating and/or accentuated vasodilation. The specific aims are (1) to compare core and skin temperature responses during moderate exercise before flight and inflight; (2) to determine whether the hypothesized inflight excessive hyperthermia is due to increased heat production, reduced, sweating, impaired peripheral vasodilation, or to some combination of these factors; and (3) to determine whether heat production at an exercise load of 60 percent of the maximal working capacity is similar preflight and inflight. It is expected that the astronauts will exhibit excessive hyperthermia during exposure to microgravity which will be caused by decreased sweating and decreased skin blood flow.

Poorer positive affect in response to self-paced exercise among the obese.

PubMed

Elsangedy, Hassan M; Nascimento, Paulo H D; Machado, Daniel G S; Krinski, Kleverton; Hardcastle, Sarah J; DaSilva, Sérgio G

2018-05-15

We aimed to investigate the association between body mass index (BMI) and affective response, ratings of perceived exertion (RPE), and physiological responses during self-paced exercise. Sixty-six women were divided into three groups accordingly with the BMI: obese (n = 22: 33.5 ± 8.5 yr; 34.9 ± 4.1 kg∙m -2 ), overweight (n = 22: 34.8 ± 8.6 yr; 26.4 ± 1.3 kg∙m -2 ), and normal-weight (n = 22: 30.8 ± 9.3 yr; 22.0 ± 1.6 kg∙m -2 ). They underwent a graded exercise test and a 20-min self-paced walking session on a treadmill. Affective responses, RPE, heart rate (HR), and oxygen uptake (VO 2 ) were recorded every 5 min. The women with obesity experienced the lowest affective rates (p < .001), despite similar RPE, HR, and VO 2 to the other normal weight and overweight groups. In addition, a multiple regression model indicated that BMI was a significant predictor of affective responses (p < .001). In conclusion, the results of the present study suggest that obesity is associated with poorer affective responses to exercise even at self-paced intensity, with the same physiological responses and perceived exertion. Therefore, techniques that aim directly to increase pleasure and/or reduce attentional focus and perception of effort in this population are required, such as affect-regulated prescription, shorter bouts of self-paced exercise throughout the day, distraction away from internal cues (e.g. music, group exercise), etc. Copyright © 2018 Elsevier Inc. All rights reserved.

Ultra short-term heart rate recovery after maximal exercise: relations to aerobic power in sportsmen.

PubMed

Ostojic, Sergej M; Stojanovic, Marko D; Calleja-Gonzalez, Julio

2011-04-30

The main aim of the study was to investigate whether different levels of aerobic power influence heart rate (HR) responses during the first minute of recovery following maximal exercise in athletes. Thirty-two young male soccer players were recruited for the study during the final week of their training prior to [corrected] the competition. Following the maximal exercise on treadmill the participants were placed supine for 60 s of HR recording. The time between exercise cessation and the recovery HR measurement was kept as short as possible. At the end of exercise (i.e., the start of recovery), HRs were [corrected] was similar in both trials. At both 10 s and 20 s of recovery period, the players characterized by high aerobic power (> 60 ml/kg/ min) revealed significantly lower HR as compared to their sub-elite counterparts (< 50 ml/kg/min; P < 0.05). No differences between the groups were found at later stages of the analyzed post-exercise HR. The data suggest that the athletes characterized by high aerobic capacity could be better adapted to maximal exercise with faster recovery HR immediately following an exercise test. These results generally suggest that the aerobic power along with autonomic modulation might have played a role in the ultra short-term cardiovascular responses to all-out exercise.

Changes in plasma volume and baroreflex function following resistance exercise

NASA Technical Reports Server (NTRS)

Ploutz, L. L.; Tatro, D. L.; Dudley, G. A.; Convertino, V. A.

1993-01-01

The dynamics of change in plasma volume (PV) and baroreflex responses have been reported over 24 h immediately following maximal cycle exercise. The purpose of this study was to determine if PV and baroreflex showed similar changes for 24 h after resistance exercise. Eight men were studied on 2 test days, 1 week apart. On 1 day, per cent change (% delta) in PV was estimated at 0,3, and 6 h after resistance exercise using haematocrit and haemoglobin. Baseline PV was measured 24 h after exercise using Evans blue dye. The carotid baroreceptor-cardiac reflex response was measured before, and 3, 6, 9, 12, and 24 h post-exercise. Each subject performed six sets of the bench press and leg press with 10 repetitions per set with a load that induced failure within each set. On a control day, the protocol was used without exercise. Plasma volume did not change during the control day. There was a 20% decrease in PV immediately post-exercise; the recovery of the PV was rapid and complete within 3 h. PV was 20% greater 24 h post-exercise than on the control day. There were no differences in any of the baroreflex measurements. Therefore, it is suggested that PV shifts may occur without altering baroreflex sensitivity.

Exploring Outcome Measures for Exercise Intervention in People with Parkinson's Disease

PubMed Central

King, L. A.; Salarian, A.; Mancini, M.; Priest, K. C.; Nutt, J.; Serdar, A.; Wilhelm, J.; Schlimgen, J.; Smith, M.; Horak, F. B.

2013-01-01

Background. It is widely believed that exercise improves mobility in people with Parkinson's disease (PD). However, it is difficult to determine whether a specific type of exercise is the most effective. The purpose of this study was to determine which outcome measures were sensitive to exercise intervention and to explore the effects of two different exercise programs for improving mobility in patients with PD. Methods. Participants were randomized into either the Agility Boot Camp (ABC) or treadmill training; 4x/week for 4 weeks. Outcome measures were grouped by the International Classification of Function/Disability (ICF). To determine the responsiveness to exercise, we calculated the standardized response means. t-tests were used to compare the relative benefits of each exercise program. Results. Four of five variables at the structure/function level changed after exercise: turn duration (P = 0.03), stride velocity (P = 0.001), peak arm speed (P = 0.001), and horizontal trunk ROM during gait (P = 0.02). Most measures improved similarly for both interventions. The only variable that detected a difference between groups was postural sway in ABC group (F = 4.95; P = 0.03). Conclusion. Outcome measures at ICF body structure/function level were most effective at detecting change after exercise and revealing differences in improvement between interventions. PMID:23738230

Development and field test of a responsible alcohol service program. Volume 3, Final results

DOT National Transportation Integrated Search

1988-08-01

A Program of Responsible Alcohol Service was developed to enable servers and managers in establishments selling alcoholic beverages to exercise responsibility in their service of alcohol in order to prevent injury to and by intoxicated patrons. The P...

Development and field test of a responsible alcohol service program. Volume 1, Research findings

DOT National Transportation Integrated Search

1987-03-01

A program of responsible alcohol service was developed to enable servers and managers in establishments selling alcoholic beverages to exercise responsibility in their service of alcohol in order to prevent injury to and by intoxicated patrons. The P...

Physical exercise improves learning in zebrafish, Danio rerio.

PubMed

Luchiari, Ana Carolina; Chacon, Diana Marques Martins

2013-11-01

Zebrafish is an ideal vertebrate model for neuroscience studies focusing on learning and memory. Although genetic manipulation of zebrafish is available, behavioral protocols are often lacking. In this study we tested whether physical activity can facilitate zebrafish's learning process in an associative conditioning task. Learning was inferred by the approach of the feeding area just after the conditioned stimulus (light). Unexercised zebrafish showed conditioning response from the 5th testing day while fish previously submitted to swim against the water current showed learning by the 3rd day of testing. It seems that physical activity may accelerate associative learning response in zebrafish, indicating the benefits of exercise for cognitive processes. We suggest that this preliminary work could be useful for high throughput screening. Copyright © 2013 Elsevier B.V. All rights reserved.

Combined effects of mild-to-moderate obesity and asthma on physiological and sensory responses to exercise.

PubMed

Cortés-Télles, Arturo; Torre-Bouscoulet, Luis; Silva-Cerón, Monica; Mejía-Alfaro, Roberto; Syed, Nafeez; Zavorsky, Gerald S; Guenette, Jordan A

2015-11-01

Despite the close link between asthma and obesity, there are no studies that have evaluated the sensory and physiological responses to exercise in obese asthmatics. We recently demonstrated that normal weight asthmatics with well controlled disease have preserved cardiorespiratory and sensory responses to exercise relative to non-asthmatic controls. However, these similarities may not hold true in patients with combined obesity and asthma. Accordingly, we sought to determine if combined asthma and obesity was associated with deleterious effects on cardiorespiratory fitness, exercise performance, dyspnoea, and physiological responses to exercise. Fourteen well-controlled obese asthmatics and fourteen age-matched normal weight asthmatics performed routine spirometry and underwent an incremental cardiopulmonary cycle test to assess the ventilatory, pulmonary gas exchange, cardiovascular, and sensory responses to exercise. Groups were well matched for age, height, spirometry, and asthma control. Obese asthmatics had a significantly greater body mass index (33 ± 3 vs. 23 ± 1 kg/m(2), p < 0.001) and lower self-reported activity levels by 47 % relative to normal weight asthmatics (p < 0.05). Obese asthmatics had a significantly lower maximal oxygen uptake (VO(2)) (82 ± 14 vs. 92 ± 10 %predicted) and work rate (75 ± 8 vs. 89 ± 13 %predicted) relative to normal weight asthmatics (p < 0.05). The anaerobic threshold occurred at a lower VO(2) in obese asthmatics vs. normal weight asthmatics (54 ± 15 vs. 66 ± 16 %predicted, p < 0.05). Ventilatory responses were superimposed throughout exercise with no evidence of a ventilatory limitation in either group. Cardiovascular responses were normal in both groups. Dyspnoea responses were similar but the obese asthmatics experienced greater leg fatigue ratings at submaximal work rates. In conclusion, obese individuals with well controlled asthma have reduced cardiorespiratory fitness and greater leg fatigue ratings relative to normal weight asthmatics. The relatively reduced cardiorespiratory fitness and exercise performance in obese compared to normal weight asthmatics is most likely driven by their more sedentary lifestyle and resultant deconditioning rather than due to respiratory factors. Copyright © 2015 Elsevier Ltd. All rights reserved.

The Effect of a 20 km Run on Appetite Regulation in Long Distance Runners

PubMed Central

Kojima, Chihiro; Ishibashi, Aya; Ebi, Kumiko; Goto, Kazushige

2016-01-01

The purpose of the present study was to investigate appetite-related hormonal responses and energy intake after a 20 km run in trained long distance runners. Twenty-three male long-distance runners completed two trials: either an exercise trial consisting of a 20 km outdoor run (EX) or a control trial with an identical period of rest (CON). Blood samples were collected to determine plasma acylated ghrelin, peptide YY3-36 (PYY3-36) and other hormonal and metabolite concentrations. Energy intake during a buffet test meal was also measured 30 min after the exercise or rest periods. Although plasma acylated ghrelin concentrations were significantly decreased after the 20 km run (p < 0.05), plasma PYY3-36 did not change significantly following exercise. Absolute energy intake during the buffet test meal in EX (1325 ± 55 kcal) was significantly lower than that in CON (1529 ± 55 kcal), and there was a relatively large degree of individual variability for exercise-induced changes in energy intake (−40.2% to 12.8%). However, exercise-induced changes in energy intake were not associated with plasma acylated ghrelin or PYY3-36 responses. The results demonstrated that a 20 km run significantly decreased plasma acylated ghrelin concentrations and absolute energy intake among well-trained long distance runners. PMID:27792164

Pre- versus post-exercise protein intake has similar effects on muscular adaptations.

PubMed

Schoenfeld, Brad Jon; Aragon, Alan; Wilborn, Colin; Urbina, Stacie L; Hayward, Sara E; Krieger, James

2017-01-01

The purpose of this study was to test the anabolic window theory by investigating muscle strength, hypertrophy, and body composition changes in response to an equal dose of protein consumed either immediately pre- versus post-resistance training (RT) in trained men. Subjects were 21 resistance-trained men (>1 year RT experience) recruited from a university population. After baseline testing, participants were randomly assigned to 1 of 2 experimental groups: a group that consumed a supplement containing 25 g protein and 1 g carbohydrate immediately prior to exercise (PRE-SUPP) ( n  = 9) or a group that consumed the same supplement immediately post-exercise (POST-SUPP) ( n  = 12). The RT protocol consisted of three weekly sessions performed on non-consecutive days for 10 weeks. A total-body routine was employed with three sets of 8-12 repetitions for each exercise. Results showed that pre- and post-workout protein consumption had similar effects on all measures studied ( p  > 0.05). These findings refute the contention of a narrow post-exercise anabolic window to maximize the muscular response and instead lends support to the theory that the interval for protein intake may be as wide as several hours or perhaps more after a training bout depending on when the pre-workout meal was consumed.

Cellular Stress Response Gene Expression During Upper and Lower Body High Intensity Exercises

PubMed Central

Kochanowicz, Andrzej; Sawczyn, Stanisław; Niespodziński, Bartłomiej; Mieszkowski, Jan; Kochanowicz, Kazimierz

2017-01-01

Objectives The aim was to compare the effect of upper and lower body high-intensity exercise on chosen genes expression in athletes and non-athletes. Method Fourteen elite male artistic gymnasts (EAG) aged 20.6 ± 3.3 years and 14 physically active men (PAM) aged 19.9 ± 1.0 years performed lower and upper body 30 s Wingate Tests. Blood samples were collected before, 5 and 30 minutes after each effort to assess gene expression via PCR. Results Significantly higher mechanical parameters after lower body exercise was observed in both groups, for relative power (8.7 ± 1.2 W/kg in gymnasts, 7.2 ± 1.2 W/kg in controls, p = 0.01) and mean power (6.7 ± 0.7 W/kg in gymnasts, 5.4 ± 0.8 W/kg in controls, p = 0.01). No differences in lower versus upper body gene expression were detected for all tested genes as well as between gymnasts and physical active man. For IL-6 m-RNA time-dependent effect was observed. Conclusions Because of no significant differences in expression of genes associated with cellular stress response the similar adaptive effect to exercise may be obtained so by lower and upper body exercise. PMID:28141870

[Cardiovascular resistance to orthostatic stress in athletes after aerobic exercise].

PubMed

Mel'nikov, A A; Popov, S G; Vikulov, A D

2014-01-01

In the paper cardiovascular resistance to orthostatic stress in the athletes in the two-hour recovery period after prolonged aerobic exercise was investigated. The reaction of the cardiac (stroke volume and cardiac output) and peripheral blood volumes in the lower and upper limbs, abdominal and neck regions in response to the tilt-test before and during two hours after exercise (30 min, heart rate = 156 +/- 8 beats/min) was determined by impedance method: It is found that: (1) at baseline distribution of blood flow in favor of the neck-region in response to the tilt-test, in spite of the decrease in cardiac output, was more efficient in athletes, that was due to a large decrease in blood flow to the lower extremities, and increased blood flow in the neck region; (2) after exercise it was established symptoms of potential orthostatic intolerance: postural hypotension and tachycardia, reduced peripheral pulse blood volume, expressed in a standing position, and reduced effectiveness of the distribution of blood flow in the direction of the neck region; (3) the abilityto effectively distribute blood flow in favor of the neck region in athletes after exercise remained elevated, which was due to a large decrease in blood flow in the abdominal region at the beginning, and in the lower limbs at the end of the recovery period.

Muscle performance following an acute bout of plyometric training combined with low or high intensity weight exercise.

PubMed

Beneka, Anastasia G; Malliou, Paraskevi K; Missailidou, Victoria; Chatzinikolaou, Athanasios; Fatouros, Ioannis; Gourgoulis, Vassilios; Georgiadis, Elias

2013-01-01

To determine the time course of performance responses after an acute bout of plyometric exercise combined with high and low intensity weight training, a 3-group (including a control group), repeated-measures design was employed. Changes in performance were monitored through jumping ability by measuring countermovement and squat jumping, and strength performance assessment through isometric and isokinetic testing of knee extensors (at two different velocities). Participants in both experimental groups performed a plyometric protocol consisting of 50 jumps over 50 cm hurdles and 50 drop jumps from a 50 cm plyometric box. Additionally, each group performed two basic weight exercises consisting of leg presses and leg extensions at 90-95% of maximum muscle strength for the high intensity group and 60% of maximum muscle strength for the low intensity group. The results of the study suggest that an acute bout of intense plyometric exercise combined with weight exercise induces time-dependent changes in performance, which are also dependent on the nature of exercise protocol and testing procedures. In conclusion, acute plyometric exercise with weight exercise may induce a substantial decline in jumping performance for as long as 72 hours but not in other forms of muscle strength.

Short-term reliability of inflammatory mediators and response to exercise in the heat.

PubMed

Guy, Joshua H; Edwards, Andrew M; Miller, Catherine M; Deakin, Glen B; Pyne, David B

2017-08-01

Prospective application of serum cytokines, lipopolysaccharide (LPS), and heat shock proteins (eHSPs) requires reliable measurement of these biomarkers that can signify exercise-induced heat stress in hot conditions. To accomplish this, both short-term (7 day) reliability (at rest, n = 12) and the acute responsiveness of each biomarker to exercise in the heat (pre and post 60-min cycling, 34.5°C and 70% RH, n = 20) were evaluated. Serum was analysed for the concentration of C-reactive protein (CRP), interleukin-6 (IL-6), heat shock protein 72 (eHSP72), immunoglobulin M (IgM) and LPS. Test-retest reliability was determined as the coefficient of variation (CV). Biomarkers with the least short-term within-participant variation were IL-6 (19%, ±20%; CV, ±95% confidence limits (CL)) and LPS (23%, ±13%). Greater variability was observed for IgM, eHSP72 and CRP (CV range 28-38%). IL-6 exhibited the largest increase in response to acute exercise (95%, ±11%, P = < 0.001) and although CRP had a modest CV (12%, ±7%), it increased substantially post-exercise (P = 0.02, ES; 0.78). In contrast, eHSP72 and LPS exhibited trivial changes post-exercise. It appears variation of common inflammatory markers after exercise in the heat is not always discernible from short-term (weekly) variation.

A Comparison of Exercise and Meditation in Reducing Physiological Response to Stress.

ERIC Educational Resources Information Center

Sime, Wesley E.

The purpose of this investigation was to compare the effects of brief treadmill exercise and meditation with a placebo-control treatment for reduction in several physiological and psychological measures of stress, anxiety, and tension before and after a written final examination in 48 high-test anxiety subjects. The subjects, 24 men and 24 women,…

Recovery Responses to Maximal Exercise in Healthy-Weight Children and Children with Obesity

ERIC Educational Resources Information Center

Easley, Elizabeth A.; Black, W. Scott; Bailey, Alison L.; Lennie, Terry A.; Sims, Wilma J.; Clasey, Jody L.

2018-01-01

Purpose: The purpose of this study was to examine differences in heart rate recovery (HRRec) and oxygen consumption recovery (VO2 recovery) between young healthy-weight children and children with obesity following a maximal volitional graded exercise test (GXTmax). Method: Twenty healthy-weight children and 13 children with obesity completed body…

Effects of menstrual cycle, oral contraception, and training on exercise-induced changes in circulating DHEA-sulphate and testosterone in young women.

PubMed

Enea, C; Boisseau, N; Ottavy, M; Mulliez, J; Millet, C; Ingrand, I; Diaz, V; Dugué, B

2009-06-01

The objective of this study was to ascertain the effects of menstrual cycle, oral contraception, and training status on the exercise-induced changes in circulating DHEA-sulphate and testosterone in young women. Twenty-eight healthy women were assigned to an untrained group (n = 16) or a trained group (n = 12) depending on their training background. The untrained group was composed of nine oral contraceptive users (OC+) and seven eumenorrheic women (OC-). The trained group was composed of OC+ subjects only. All the OC+ subjects were taking the same low-dose oral contraception. Three laboratory sessions were organised in a randomised order: a prolonged exercise test until exhaustion, a short-term exhaustive exercise test, and a control session. Blood specimens were collected before, during and after the exercise tests and at the same time of the day during the control session. Basal circulating testosterone was significantly lower in trained as compared to untrained subjects. In all subjects, the prolonged exhaustive exercise induced a significant increase in circulating DHEA-s and testosterone. The short-term exercise induced a significant increase in circulating DHEA-s in untrained eumenorrheic and in trained OC users only. Menstrual phases in OC- did not influence the responses. It was found that exhaustive physical exercise induced an increase in circulating DHEA-s and testosterone in young women. Oral contraception may limit short-term exercise-induced changes.

Pyridostigmine bromide does not alter thermoregulation during exercise in cold air

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roberts, D.E.; Sawka, M.N.; Young, A.J.

1994-12-31

This study examined the effects of acute and chronic pyridostigmine bromide (PB) administration on thermoregulatory and metabolic responses to exercise in cold air (5 C). Seven healthy men completed two 7-day trials in a double-blind, crossover experimental design: during one trial they received PB (30 mg three times daily) and during the other trial they received placebo. For each trial, subjects attempted four (3 h) exercise tests: low-intensity exercise (25% Vo2max) and moderate- intensity exercise (-50% Vo2max), on days 2 and 3 and again on days 6 and 7. Metabolic rate, body temperatures, and venous blood samples were obtained beforemore » and during exercise. Red blood cell acerylcholinesterase inhibition induced by PB increased (p < 0.05) from 34% on day I to 43% on days 3-7 Metabolic rate, body temperatures, and regional heat conductance responses were not different between trials. Plasma glucose, glycerol, free fatty acid, lactate, sodium, and potassium concentrations were not different between trials. In addition. differences were not found between acute and chronic experiments for any thermoregulatory or metabolic responses. These findings demonstrate that the PB dosage used by military personnel, as a pharmacological defense against nerve-agent poisoning. should not cause any adverse thermoregulatory or metabolic effects during moderate activity in cold climates.« less

Development of an Online Toolkit for Measuring Performance in Health Emergency Response Exercises.

PubMed

Agboola, Foluso; Bernard, Dorothy; Savoia, Elena; Biddinger, Paul D

2015-10-01

Exercises that simulate emergency scenarios are accepted widely as an essential component of a robust Emergency Preparedness program. Unfortunately, the variability in the quality of the exercises conducted, and the lack of standardized processes to measure performance, has limited the value of exercises in measuring preparedness. In order to help health organizations improve the quality and standardization of the performance data they collect during simulated emergencies, a model online exercise evaluation toolkit was developed using performance measures tested in over 60 Emergency Preparedness exercises. The exercise evaluation toolkit contains three major components: (1) a database of measures that can be used to assess performance during an emergency response exercise; (2) a standardized data collection tool (form); and (3) a program that populates the data collection tool with the measures that have been selected by the user from the database. The evaluation toolkit was pilot tested from January through September 2014 in collaboration with 14 partnering organizations representing 10 public health agencies and four health care agencies from eight states across the US. Exercise planners from the partnering organizations were asked to use the toolkit for their exercise evaluation process and were interviewed to provide feedback on the use of the toolkit, the generated evaluation tool, and the usefulness of the data being gathered for the development of the exercise after-action report. Ninety-three percent (93%) of exercise planners reported that they found the online database of performance measures appropriate for the creation of exercise evaluation forms, and they stated that they would use it again for future exercises. Seventy-two percent (72%) liked the exercise evaluation form that was generated from the toolkit, and 93% reported that the data collected by the use of the evaluation form were useful in gauging their organization's performance during the exercise. Seventy-nine percent (79%) of exercise planners preferred the evaluation form generated by the toolkit to other forms of evaluations. Results of this project show that users found the newly developed toolkit to be user friendly and more relevant to measurement of specific public health and health care capabilities than other tools currently available. The developed toolkit may contribute to the further advancement of developing a valid approach to exercise performance measurement.

Exercise induced bronchospasm in Ghana: differences in prevalence between urban and rural schoolchildren

PubMed Central

Addo, Y; Custovic, A.; Taggart, S. C.; Asafo-Agyei, A. P.; Woodcock, A.

1997-01-01

BACKGROUND: As more developing countries adopt a westernised style of living, an increase in the prevalence of asthma can be expected to occur in these areas. A study was undertaken to establish the normal response to exercise in Ghanaian children and to use these normal values to determine the prevalence of exercise induced bronchospasm (EIB) in urban rich (UR), urban poor (UP), and rural (R) school children. Skin test reactivity to common inhalant allergens in UR, UP, and R children with and without EIB was also investigated. METHODS: Two hundred children aged 9-16 years without a previous history of respiratory symptoms were randomly selected and underwent free running exercise testing. A normal response to exercise was defined as the group mean change in peak expiratory flow rate (PEFR) +/- 2 standard deviations. This value was used to identify the prevalence of EIB in UR, UP, and R schoolchildren. A total of 1095 children from three different schools underwent exercise testing (220 UP, 599 UR, 276 R), after which 916 children underwent skin prick testing to six common inhalant allergens (D farinae, D pteronyssinus, cat, dog, Aspergillus flavus and Candida albicans). RESULTS: From the results of exercise testing in asymptomatic children the normal range was defined as a fall in PEFR of < 12.5% after exercise. Thirty four children were classified as having EIB on the basis of the above definition, giving an overall prevalence of 3.1%. The prevalence of EIB was significantly higher in UR children (4.7%) than in both UP (2.2%; p < 0.05) and R children (1.4%; p < 0.01). However, the prevalence rates in the UP and R children were similar. The prevalence of atopy in the whole population was 4.4%. Of the children with EIB, 10% were skin test positive to at least one of the allergens tested. The prevalence of atopy was significantly higher in UR children (6.55%, 95% confidence interval (CI) 4.5% to 9.2%) than in UP (2.9%, 95% CI 0.9% to 6.7%) and R children (1.5%, 95% CI 0.4% to 3.7%), respectively (p < 0.005). CONCLUSIONS: The prevalence of EIB and atopy is higher in urban rich than in urban poor or rural children suggesting that, in addition to genetic predisposition, social and environmental factors such as wealth, life style, and housing are important determinants of these phenotypes. 


 PMID:9059478

Exercise offers anxiolytic potential: A role for stress and brain noradrenergic-galaninergic mechanisms

PubMed Central

Sciolino, Natale R.; Holmes, Philip V.

2016-01-01

Although physical activity reduces anxiety in humans, the neural basis for this response is unclear. Rodent models are essential to understand the mechanisms that underlie the benefits of exercise. However, it is controversial whether exercise exerts anxiolytic-like potential in rodents. Evidence is reviewed to evaluate the effects of wheel running, an experimental mode of exercise in rodents, on behavior in tests of anxiety and on norepinephrine and galanin systems in neural circuits that regulate stress. Stress is proposed to account for mixed behavioral findings in this literature. Indeed, running promotes an adaptive response to stress and alters anxiety-like behaviors in a manner dependent on stress. Running amplifies galanin expression in noradrenergic locus coeruleus (LC) and suppresses stress-induced activity of the LC and norepinephrine output in LC-target regions. Thus, enhanced galanin-mediated suppression of brain norepinephrine in runners is supported by current literature as a mechanism that may contribute to the stress-protective effects of exercise. These data support the use of rodents to study the emotional and neurobiological consequences of exercise. PMID:22771334

Acute physiological responses to recreational in-line skating in young adults.

PubMed

Orepic, Paula; Mikulic, Pavle; Soric, Maroje; Ruzic, Lana; Markovic, Goran

2014-01-01

We examined the physiological responses to in-line skating exercise at self-selected paces in recreationally trained adults. Seven men and 10 women performed in-line skating exercise during which oxygen uptake (VO2) and heart rate (HR) were recorded continuously. Ratings of perceived exertion (RPE) and blood lactate concentration were also obtained at the end of exercise. Furthermore, subjects' peak VO2, peak HR, RPE and gas-exchange thresholds were determined in laboratory settings. The average exercise intensity during in-line skating was 90% of peak HR, 67% of peak VO2, 84% of HR reserve and 64% of VO2 reserve. When expressed as RPE and as metabolic equivalents (METs), the average exercise intensity was 13.1 RPE and 9.4 METs. Overall, these indicators of exercise intensity categorise in-line skating at self-selected paces as a vigorous physical activity. Notably, at similar VO2 values, significantly higher HR (174 ± 16 vs. 156 ± 6 bpm; p<0.001) and RPE (13.1 ± 1.4 vs. 11.7 ± 1.4; p=0.019) were observed for in-line skating compared with treadmill running. We conclude that 1. recreational in-line skating induces physiological responses that are sufficient for improving and maintaining cardiovascular fitness in healthy adults, 2. HR- and RPE-based methods for quantifying the exercise intensity during in-line skating may overestimate the actual metabolic load and 3. the derivation of exercise prescriptions for in-line skating should be preferably based on specific (i.e. in-line skating) graded exhaustive exercise test.

Effect of resistance exercise intensity on the expression of PGC-1α isoforms and the anabolic and catabolic signaling mediators, IGF-1 and myostatin, in human skeletal muscle.

PubMed

Schwarz, Neil A; McKinley-Barnard, Sarah K; Spillane, Mike B; Andre, Thomas L; Gann, Joshua J; Willoughby, Darryn S

2016-08-01

The purpose of this study was to investigate the acute messenger (mRNA) expression of the peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) isoforms, insulin-like growth factor-1Ea (IGF-1Ea), and myostatin in response to 2 resistance exercise intensities. In a uniform-balanced, crossover design, 10 participants performed 2 separate testing sessions involving a lower body resistance exercise component consisting of a lower intensity (50% of 1-repetition maximum; 1RM) protocol and a higher intensity (80% of 1RM) protocol of equal volumes. Muscle samples were obtained at before exercise, 45 min, 3 h, 24 h, and 48 h postexercise. Resistance exercise did not alter total PGC-1α mRNA expression; however, distinct responses of each PGC-1α isoform were observed. The response of each isoform was consistent between sessions, suggesting no effect of resistance exercise intensity on the complex transcriptional expression of the PGC-1α gene. IGF-1Ea mRNA expression significantly increased following the higher intensity session compared with pre-exercise and the lower intensity session. Myostatin mRNA expression was significantly reduced compared with pre-exercise values at all time points with no difference between exercise intensity. Further research is needed to determine the effects of the various isoforms of PGC-1α in human skeletal muscle on the translational level as well as their relation to the expression of IGF-1 and myostatin.

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

Effects of exercise position on the ventilatory responses to exercise in chronic heart failure.

PubMed

Armour, W; Clark, A L; McCann, G P; Hillis, W S

1998-09-01

Patients with heart failure frequently complain of orthopnoea. The objective was to assess the ventilatory response of patients with chronic heart failure during erect and supine exercise. Maximal incremental exercise testing with metabolic gas exchange measurements in erect and supine positions conducted in random order. Tertiary referral centre for cardiology. Nine patients with heart failure (aged 61.9+/-6.1 years) and 10 age matched controls (63.8+/-4.6). Metabolic gas exchange measurements. The slope of the relation between ventilation and carbon dioxide production. Ratings of perceived breathlessness during exercise. Oxygen consumption (VO2) and ventilation were higher during erect exercise at each stage in each group. Peak VO2 was [mean (SD)] 17.12 ml/kg/min (4.07) erect vs 12.92 (3.61) supine in the patients (P<0.01) and 22.62 (5.03) erect-supine vs 19.16 (3.78) erect (P<0.01) in the controls. Ratings of perceived exertion were higher in the patients at each stage, but unaffected by posture. There was no difference in the slope of the relation between ventilation and carbon dioxide production between erect and supine exercise 36.39 (6.12) erect vs 38.42 (8.89) supine for patients; 30.05 (4.52) vs 28.80 (3.96) for controls. In this group of patients during exercise, there was no change in the perception of breathlessness, nor the ventilatory response to carbon dioxide production with change in posture, although peak ventilation was greater in the erect position. The sensation of breathlessness may be related to the appropriateness of the ventilatory response to exertion rather than to the absolute ventilation.

Hemodynamic responses to a community-based Tai Chi exercise intervention in ethnic Chinese adults with cardiovascular disease risk factors.

PubMed

Taylor-Piliae, Ruth E; Haskell, William L; Froelicher, Erika Sivarajan

2006-06-01

Cardiovascular disease (CVD) is the leading cause of death among older adults worldwide, including Europe, Asia, and North America. In the United States (US), CVD is also the leading cause of death among Asian-Americans. Physical activity has been shown to reduce CVD risk factors. Reduction in blood pressure (BP) in response to Tai Chi (TC) exercise in persons with CVD risk factors have been reported, though not in ethnic Chinese living in the US. Hemodynamic responses to a 12-week community-based TC exercise intervention among ethnic Chinese with CVD risk factors were examined. Quasi-experimental design. Ethnic Chinese > 45 years old with at least 1 major CVD risk factor, living in the San Francisco Bay Area, attended a TC intervention three times a week for 12 weeks. A 2-min step-in-place test assessed aerobic endurance. BP and heart rate were measured at rest, and within 1-min after the step-test. Data were collected at baseline, 6 and 12 weeks. A total of 39 subjects (69% women), 66 +/- 8.3 years old, with hypertension (92%), hypercholesteremia (49%), and/or diabetes (21%), and 1 current smoker participated. Adherence to the intervention was high (87%). Subjects were sedentary at baseline, though had a statistically significant improvement in aerobic endurance over-time (eta2 = 0.39). At baseline, the average BP at rest was 150/86, while BP in response to the step-test was 178/99. Clinically and statistically significant reductions in BP at rest (131/77), and in response to the step-test (164/82) were found over 12 weeks of TC (p < 0.01). No significant change in heart rate was observed. This innovative, culturally relevant, community-based 12-week TC exercise intervention, appealed to Chinese adults with CVD risk factors, with significant reductions in BP and improvement in aerobic endurance. Given the number of persons estimated to have HTN and other CVD risk factors, the identification of new approaches to improve health, combined with risk factor reduction is needed. This is particularly important, given the rise in HTN among adults in the US and the associated public health burden of HTN. TC has the potential to reduce expenditures associated with CVD by facilitating a lifestyle that promotes physical activity, while remaining a low-tech, low-cost alternative to exercise.

Bone marrow fat accumulation accelerated by high fat diet is suppressed by exercise

PubMed Central

Styner, Maya; Thompson, William R.; Galior, Kornelia; Uzer, Gunes; Wu, Xin; Kadari, Sanjay; Case, Natasha; Xie, Zhihui; Sen, Buer; Romaine, Andrew; Pagnotti, Gabriel M.; Rubin, Clinton T.; Styner, Martin A.; Horowitz, Mark C.; Rubin, Janet

2014-01-01

Marrow adipose tissue (MAT), associated with skeletal fragility and hematologic insufficiency, remains poorly understood and difficult to quantify. We tested the response of MAT to high fat diet (HFD) and exercise using a novel volumetric analysis, and compared it to measures of bone quantity. We hypothesized that HFD would increase MAT and diminish bone quantity, while exercise would slow MAT acquisition and promote bone formation. Eight week-old female C57BL/6 mice were fed a regular (RD) or HFD, and exercise groups were provided voluntary access to running wheels (RD-E, HFD-E). Femoral MAT was assessed by μCT (lipid binder osmium) using a semi-automated approach employing rigid co-alignment, regional bone masks and was normalized for total femoral volume (TV) of the bone compartment. MAT was 2.6-fold higher in HFD relative to RD mice. Exercise suppressed MAT in RD-E mice by more than half compared with RD. Running similarly inhibited MAT acquisition in HFD mice. Exercise significantly increased bone quantity in both diet groups. Thus, HFD caused significant accumulation of MAT; importantly running exercise limited MAT acquisition while promoting bone formation during both diets. That MAT is exquisitely responsive to diet and exercise, and its regulation by exercise appears to be inversely proportional to effects on exercise induced bone formation, is relevant for an aging and sedentary population. PMID:24709686

Hypothalamic GABAergic influences on treadmill exercise responses in rats.

PubMed

Overton, J M; Redding, M W; Yancey, S L; Stremel, R W

1994-01-01

Microinjection of GABAergic antagonists in the posterior hypothalamus (PH) produces exercise-like adjustments in cardiovascular function. To test the hypothesis that a hypothalamic GABAergic mechanism within the PH modulates the cardiovascular adjustments to dynamic exercise in conscious animals, Sprague-Dawley rats (n = 10) were instrumented with bilateral guide cannula directed at the pH, an arterial cannula, and Doppler flow probes on the iliac and mesenteric arteries. Saline (100 nl) or the GABAA receptor agonist muscimol (125 ng.100 nl-1) was bilaterally injected into the PH during treadmill exercise (20 m.min-1). Microinjection of saline had no effect on mean arterial pressure (MAP), heart rate (HR), mesenteric vascular resistance (MR), or iliac vascular resistance (IR) during exercise. Microinjection of muscimol during exercise produced no significant changes in MAP (mean change +/- SE; +0 +/- 1 mmHg), HR (+17 +/- 12 b.min-1), or MR (+7 +/- 13%). However, microinjection of muscimol produced a significant increase in IR during exercise (16 +/- 6%). In addition, muscimol significantly decreased treadmill run time (saline = 19.6 +/- 0.4 min; muscimol = 17.8 +/- 0.6 min) and produced behavioral effects (including mild sedation) that were most evident after exercise. The results of these experiments suggest that while the posterior hypothalamic GABAergic system may modulate iliac blood flow during exercise in rats, this system does not modulate HR and MR responses to dynamic exercise.

Endurance exercise modulates levodopa induced growth hormone release in patients with Parkinson's disease.

PubMed

Müller, Thomas; Welnic, Jacub; Woitalla, Dirk; Muhlack, Siegfried

2007-07-11

Acute levodopa (LD) application and exercise release human growth hormone (GH). An earlier trial showed, that combined stimulus of exercise and LD administration is the best provocative test for GH response in healthy participants. Objective was to show this combined effect of LD application and exercise on GH response and to investigate the impact on LD metabolism in 20 previously treated patients with Parkinson's disease (PD). We measured GH- and LD plasma concentrations following soluble 200 mg LD/50 mg benserazide administration during endurance exercise and rest on two separate consecutive days. GH concentrations significantly increased on both days, but GH release was significantly delayed during rest. LD metabolism was not altered due to exercise in a clinical relevant manner. Exercise induced a significant faster LD stimulated GH release in comparison with the rest condition. We did not find the supposed increase of LD induced GH release by endurance exercise. We assume, that only a limited amount of GH is available for GH release in the anterior pituitary following an acute 200 mg LD administration. GH disposal also depends on growth hormone releasing hormone (GHRH), which is secreted into hypothalamic portal capillaries. During the exercise condition, the resulting higher blood pressure supports blood flow and thus GHRH transport towards the GH producing cells in the pituitary. This might additionally have caused the significant faster GH release during exercise.

Feasibility of a 6-month exercise and recreation program to improve executive functioning and memory of individuals with chronic stroke

PubMed Central

Rand, Debbie; Eng, Janice J.; Liu-Ambrose, Teresa; Tawashy, Amira E.

2011-01-01

Background Physical activity has been shown to be beneficial for improving cognitive function in healthy older adults. However there is limited research on the benefits of physical activity on cognitive performance after stroke. Objective To determine if a combined exercise and recreation program can improve the executive functioning and memory in individuals with chronic stroke. Methods 11 ambulatory subjects with chronic stroke (mean age 67±10.8 years) participated in a 6 month program of exercise for 2 hours and recreation for 1 hour weekly. Executive functions and memory were assessed at baseline, 3, and 6 months by a battery of standard neuropsychological tests including response inhibition, cognitive flexibility, dual task (motor plus cognitive) and memory. Motor ability was also assessed. Non-parametric statistics were used to assess the differences between the three assessments. Results At baseline, substantial deficits in all aspects of executive functioning were revealed. From baseline to 3 mo, the mean improvement was 10±14% (χ2=9.3, p=0.0025) for the dual task (Walking while Talking), −3±22% (χ2=2.4, p>0.05) for response inhibition (Stroop test) and 61±69% (χ2=8.0, p=0.04) for memory (Rey Auditory Verbal Learning Test - long delay). From baseline to 6 months, the mean improvement was 7±7.5% (χ2=12.0, p=0.007) for response inhibition (Stroop Test). In addition, knee strength and walking speed improved significantly at 3 months. Conclusions This pilot study suggests that exercise and recreation may improve memory and executive functions of community dwelling individuals with stroke. Further studies require a larger sample size and a control group. PMID:20460494

Endothelium-dependent vasodilatation and exercise hyperaemia in ageing humans: impact of acute ascorbic acid administration

PubMed Central

Kirby, Brett S; Voyles, Wyatt F; Simpson, Carrie B; Carlson, Rick E; Schrage, William G; Dinenno, Frank A

2009-01-01

Age-related increases in oxidative stress impair endothelium-dependent vasodilatation in humans, leading to the speculation that endothelial dysfunction contributes to impaired muscle blood flow and vascular control during exercise in older adults. We directly tested this hypothesis in 14 young (22 ± 1 years) and 14 healthy older men and women (65 ± 2 years). We measured forearm blood flow (FBF; Doppler ultrasound) and calculated vascular conductance (FVC) responses to single muscle contractions at 10, 20 and 40% maximum voluntary contraction (MVC) before and during ascorbic acid (AA) infusion, and we also determined the effects of AA on muscle blood flow during mild (10% MVC) continuous rhythmic handgrip exercise. For single contractions, the peak rapid hyperaemic responses to all contraction intensities were impaired ∼45% in the older adults (all P < 0.05), and AA infusion did not impact the responses in either age group. For the rhythmic exercise trial, FBF (∼28%) and FVC (∼31%) were lower (P= 0.06 and 0.05) in older versus young adults after 5 min of steady-state exercise with saline. Subsequently, AA was infused via brachial artery catheter for 10 min during continued exercise. AA administration did not significantly influence FBF or FVC in young adults (1–3%; P= 0.24–0.59), whereas FBF increased 34 ± 7% in older adults at end-exercise, and this was due to an increase in FVC (32 ± 7%; both P < 0.05). This increase in FBF and FVC during exercise in older adults was associated with improvements in vasodilator responses to acetylcholine (ACh; endothelium dependent) but not sodium nitroprusside (SNP; endothelium independent). AA had no effect on ACh or SNP responses in the young. We conclude that acute AA administration does not impact the observed age-related impairment in the rapid hyperaemic response to brief muscle contractions in humans; however, it does significantly increase muscle blood flow during continuous dynamic exercise in older adults, and this is probably due (in part) to an improvement in endothelium-dependent vasodilatation. PMID:19307300

Change in convergence and accommodation after two weeks of eye exercises in typical young adults

PubMed Central

Horwood, Anna M.; Toor, Sonia S.; Riddell, Patricia M.

2014-01-01

Background Although eye exercises appear to help heterophoria, convergence insufficiency, and intermittent strabismus, results can be confounded by placebo, practice, and encouragement effects. This study assessed objective changes in vergence and accommodation responses in naive young adults after a 2-week period of eye exercises under controlled conditions to determine the extent to which treatment effects occur over other factors. Methods Asymptomatic young adults were randomly assigned to one of two no-treatment (control) groups or to one of six eye exercise groups: accommodation, vergence, both, convergence in excess of accommodation, accommodation in excess of convergence, and placebo. Subjects were tested and retested under identical conditions, except for the second control group, who were additionally encouraged. Objective accommodation and vergence were assessed to a range of targets moving in depth containing combinations of blur, disparity, and proximity/looming cues. Results A total of 156 subjects were included. Response gain improved more for less naturalistic targets where more improvement was possible. Convergence exercises improved vergence for near across all targets (P = 0.035). Mean accommodation changed similarly but nonsignificantly. No other treatment group differed significantly from the nonencouraged control group, whereas encouraging effort produced significantly increased vergence (P = 0.004) and accommodation (P = 0.005) gains in the second control group. Conclusions True treatment effects were small, significantly better only after vergence exercises to a nonaccommodative target, and rarely related to the response they were designed to improve. Exercising accommodation without convergence made no difference to accommodation to cues containing detail. Additional effort improved objective responses the most. PMID:24582466

Effects of Aerobic Exercise on Mild Cognitive Impairment

PubMed Central

Baker, Laura D.; Frank, Laura L.; Foster-Schubert, Karen; Green, Pattie S.; Wilkinson, Charles W.; McTiernan, Anne; Plymate, Stephen R.; Fishel, Mark A.; Stennis Watson, G.; Cholerton, Brenna A.; Duncan, Glen E.; Mehta, Pankaj D.; Craft, Suzanne

2011-01-01

Objectives To examine the effects of aerobic exercise on cognition and other biomarkers associated with Alzheimer disease pathology for older adults with mild cognitive impairment, and assess the role of sex as a predictor of response. Design Six-month, randomized, controlled, clinical trial. Setting Veterans Affairs Puget Sound Health Care System clinical research unit. Participants Thirty-three adults (17 women) with amnestic mild cognitive impairment ranging in age from 55 to 85 years (mean age,70 years). Intervention Participants were randomized either to a high-intensity aerobic exercise or stretching control group. The aerobic group exercised under the supervision of a fitness trainer at 75% to 85% of heart rate reserve for 45 to 60 min/d, 4 d/wk for 6 months. The control group carried out supervised stretching activities according to the same schedule but maintained their heart rate at or below 50% of their heart rate reserve. Before and after the study, glucometabolic and treadmill tests were performed and fat distribution was assessed using dual-energy x-ray absorptiometry. At baseline, month 3, and month 6, blood was collected for assay and cognitive tests were administered. Main Outcome Measures Performance measures on Symbol-Digit Modalities, Verbal Fluency, Stroop, Trails B, Task Switching, Story Recall, and List Learning. Fasting plasma levels of insulin, cortisol, brain-derived neurotrophic factor, insulinlike growth factor-I, and β-amyloids 40 and 42. Results Six months of high-intensity aerobic exercise had sex-specific effects on cognition, glucose metabolism, and hypothalamic-pituitary-adrenal axis and trophic activity despite comparable gains in cardiorespiratory fitness and body fat reduction. For women, aerobic exercise improved performance on multiple tests of executive function, increased glucose disposal during the metabolic clamp, and reduced fasting plasma levels of insulin, cortisol, and brain-derived neurotrophic factor. For men, aerobic exercise increased plasma levels of insulinlike growth factor I and had a favorable effect only on Trails B performance. Conclusions This study provides support, using rigorous controlled methodology, for a potent nonpharma-cologic intervention that improves executive control processes for older women at high risk of cognitive decline. Moreover, our results suggest that a sex bias in cognitive response may relate to sex-based differences in glucometabolic and hypothalamic-pituitary-adrenal axis responses to aerobic exercise. PMID:20065132

Effects of aerobic exercise on mild cognitive impairment: a controlled trial.

PubMed

Baker, Laura D; Frank, Laura L; Foster-Schubert, Karen; Green, Pattie S; Wilkinson, Charles W; McTiernan, Anne; Plymate, Stephen R; Fishel, Mark A; Watson, G Stennis; Cholerton, Brenna A; Duncan, Glen E; Mehta, Pankaj D; Craft, Suzanne

2010-01-01

To examine the effects of aerobic exercise on cognition and other biomarkers associated with Alzheimer disease pathology for older adults with mild cognitive impairment, and assess the role of sex as a predictor of response. Six-month, randomized, controlled, clinical trial. Veterans Affairs Puget Sound Health Care System clinical research unit. Thirty-three adults (17 women) with amnestic mild cognitive impairment ranging in age from 55 to 85 years (mean age, 70 years). Intervention Participants were randomized either to a high-intensity aerobic exercise or stretching control group. The aerobic group exercised under the supervision of a fitness trainer at 75% to 85% of heart rate reserve for 45 to 60 min/d, 4 d/wk for 6 months. The control group carried out supervised stretching activities according to the same schedule but maintained their heart rate at or below 50% of their heart rate reserve. Before and after the study, glucometabolic and treadmill tests were performed and fat distribution was assessed using dual-energy x-ray absorptiometry. At baseline, month 3, and month 6, blood was collected for assay and cognitive tests were administered. Performance measures on Symbol-Digit Modalities, Verbal Fluency, Stroop, Trails B, Task Switching, Story Recall, and List Learning. Fasting plasma levels of insulin, cortisol, brain-derived neurotrophic factor, insulinlike growth factor-I, and beta-amyloids 40 and 42. Six months of high-intensity aerobic exercise had sex-specific effects on cognition, glucose metabolism, and hypothalamic-pituitary-adrenal axis and trophic activity despite comparable gains in cardiorespiratory fitness and body fat reduction. For women, aerobic exercise improved performance on multiple tests of executive function, increased glucose disposal during the metabolic clamp, and reduced fasting plasma levels of insulin, cortisol, and brain-derived neurotrophic factor. For men, aerobic exercise increased plasma levels of insulinlike growth factor I and had a favorable effect only on Trails B performance. This study provides support, using rigorous controlled methodology, for a potent nonpharmacologic intervention that improves executive control processes for older women at high risk of cognitive decline. Moreover, our results suggest that a sex bias in cognitive response may relate to sex-based differences in glucometabolic and hypothalamic-pituitary-adrenal axis responses to aerobic exercise.

Exercise-induced Hypoalgesia in People With Knee Osteoarthritis With Normal and Abnormal Conditioned Pain Modulation.

PubMed

Fingleton, Caitríona; Smart, Keith M; Doody, Catherine M

2017-05-01

Normal efficiency of exercise-induced hypoalgesia (EIH) has been demonstrated in people with knee osteoarthritis (OA), while recent evidence suggests that EIH may be associated with features of pain sensitization such as abnormal conditioned pain modulation (CPM). The aim of this study was to investigate whether people with knee OA with abnormal CPM have dysfunctional EIH compared with those with normal CPM and pain-free controls. Forty peoples with knee OA were subdivided into groups with abnormal and normal CPM, as determined by a decrease/increase in pressure pain thresholds (PPTs) following the cold pressor test. Abnormal CPM (n=19), normal CPM (n=21), and control participants (n=20) underwent PPT testing before, during, and after aerobic and isometric exercise protocols. Between-group differences were analyzed using repeated-measures analysis of variance and within-group differences were analyzed using Wilcoxon signed-rank tests. Significant differences were demonstrated between groups for changes in PPTs postaerobic (F2,55=4.860; P=0.011) and isometric (F2,57=4.727; P=0.013) exercise, with significant decreases in PPTs demonstrated during and postexercise in the abnormal CPM group (P<0.05), and significant increases in PPTs shown during and postexercise in the normal CPM and control groups (P<0.05). Results are suggestive of dysfunctional EIH in response to aerobic and isometric exercise in knee OA patients with abnormal CPM, and normal function of EIH in knee OA patients with an efficient CPM response. Identification of people with knee OA with inefficient endogenous pain modulation may allow for a more individualized and graded approach to exercises in these individuals.

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

PubMed Central

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

2009-01-01

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

Rectus sheath haematoma following exercise testing: a case report

PubMed Central

2009-01-01

Introduction Exercise testing is a safe diagnostic procedure which is widely used in the evaluation of patients suspected of having coronary heart disease or for the assessment of the prognosis in patients with established disease. Its complications are mainly cardiac disorders. Here, we report a rectus sheath haematoma as a complication of this procedure in a patient with acute coronary syndrome. To our knowledge, this is the first case report of rectus sheath haematoma in association with exercise testing. Case presentation A 72-year-old Caucasian woman was admitted for acute coronary syndrome. She received conservative treatment including low molecular weight heparin and anti-platelet agents. On the fifth day of her hospital stay, she underwent an exercise test, where no ischaemic response occurred. Several hours later, she experienced pain in the left side of her abdomen. Subsequent investigations revealed a rectus sheath haematoma. The patient underwent surgical haematoma evacuation. A few days later, re-operation was performed for recurrent bleeding in the abdominal wall. The patient had several characteristics known to increase the risk of bleeding during treatment for acute coronary syndrome. Conclusion Awareness of this possible consequence of exercise testing is important for preventing and treating it correctly. For prevention, an assessment of the bleeding risk of the individual patient is necessary before the test, and excessive anticoagulation must be avoided. PMID:20338023

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.

Consistency in compensatory eating responses following acute exercise in inactive, overweight and obese women.

PubMed

Unick, Jessica L; O'Leary, Kevin C; Dorfman, Leah; Thomas, J Graham; Strohacker, Kelley; Wing, Rena R

2015-04-14

It is often assumed that some individuals reliably increase energy intake (EI) post-exercise ('compensators') and some do not ('non-compensators'), leading researchers to examine the characteristics that distinguish these two groups. However, it is unclear whether EI post-exercise is stable over time. The present study examined whether compensatory eating responses to a single exercise bout are consistent within individuals across three pairs of trials. Physically inactive, overweight/obese women (n 28, BMI 30·3 (SD 2·9) kg/m²) participated in three pairs of testing sessions, with each pair consisting of an exercise (30 min of moderate-intensity walking) and resting testing day. EI was measured using a buffet meal 1 h post-exercise/rest. For each pair, the difference in EI (EIdiff = EIex - EIrest) was calculated, where EIex is the EI of the exercise session and EIrest is the EI of the resting session, and women were classified as a 'compensator' (EIex > EIrest) or 'non-compensator' (EIex ≤ EIrest). The average EI on exercise days (3328·0 (SD 1686·2) kJ) was similar to those on resting days (3269·4 (SD 1582·4) kJ) (P= 0·67). Although EI was reliable within individuals across the three resting days (intraclass correlation coefficient (ICC) 0·75, 95 % CI 0·60, 0·87; P< 0·001) and three exercise days (ICC 0·83, 95 % CI 0·70, 0·91; P< 0·001), the ICC for EIdiff across the three pairs of trials was low (ICC 0·20, 95 % CI -0·02, 0·45; P= 0·04), suggesting that compensatory eating post-exercise is not a stable construct. Moreover, the classification of 'compensators'/'non-compensators' was not reliable (κ = -0·048; P= 0·66). The results were unaltered when 'relative' EI was used, which considers the energy expenditure of the exercise/resting sessions. Acute compensatory EI following an exercise bout is not reliable in overweight women. Seeking to understand what distinguishes 'compensators' from 'non-compensators' based on a single eating episode post-exercise is not justified.

Correlations between plasma noradrenaline concentrations, antioxidants, and neutrophil counts after submaximal resistance exercise in men

PubMed Central

Ramel, A; Wagner, K; Elmadfa, I

2004-01-01

Objectives: To investigate noradrenaline concentrations, neutrophil counts, plasma antioxidants, and lipid oxidation products before and after acute resistance exercise. Methods: 17 male participants undertook a submaximal resistance exercise circuit (10 exercises; 75% of the one repetition maximum; mean (SD) exercise time, 18.6 (1.1) minutes). Blood samples were taken before and immediately after exercise and analysed for plasma antioxidants, noradrenaline, neutrophils, and lipid oxidation products. Wilcoxon's signed-rank test and Pearson's correlation coefficient were used for calculations. Results: Neutrophils, noradrenaline, fat soluble antioxidants, and lipid oxidation products increased after exercise. Noradrenaline concentrations were associated with higher antioxidant concentrations. Neutrophils were related to higher concentrations of conjugated dienes. Conclusions: Submaximal resistance exercise increases plasma antioxidants. This might reflect enhanced antioxidant defence in response to the oxidative stress of exercise, though this is not efficient for inhibiting lipid oxidation. The correlation between noradrenaline concentrations and plasma antioxidants suggests a modulating role of the stress hormone. Neutrophils are a possible source of oxidative stress after resistance exercise. PMID:15388566

Effects of negative air ions on oxygen uptake kinetics, recovery and performance in exercise: a randomized, double-blinded study

NASA Astrophysics Data System (ADS)

Nimmerichter, Alfred; Holdhaus, Johann; Mehnen, Lars; Vidotto, Claudia; Loidl, Markus; Barker, Alan R.

2014-09-01

Limited research has suggested that acute exposure to negatively charged ions may enhance cardio-respiratory function, aerobic metabolism and recovery following exercise. To test the physiological effects of negatively charged air ions, 14 trained males (age: 32 ± 7 years; : 57 ± 7 mL min-1 kg-1) were exposed for 20 min to either a high-concentration of air ions (ION: 220 ± 30 × 103 ions cm-3) or normal room conditions (PLA: 0.1 ± 0.06 × 103 ions cm-3) in an ionization chamber in a double-blinded, randomized order, prior to performing: (1) a bout of severe-intensity cycling exercise for determining the time constant of the phase II response ( τ) and the magnitude of the slow component (SC); and (2) a 30-s Wingate test that was preceded by three 30-s Wingate tests to measure plasma [adrenaline] (ADR), [nor-adrenaline] (N-ADR) and blood [lactate] (BLac) over 20 min during recovery in the ionization chamber. There was no difference between ION and PLA for the phase II τ (32 ± 14 s vs. 32 ± 14 s; P = 0.7) or SC (404 ± 214 mL vs 482 ± 217 mL; P = 0.17). No differences between ION and PLA were observed at any time-point for ADR, N-ADR and BLac as well as on peak and mean power output during the Wingate tests (all P > 0.05). A high-concentration of negatively charged air ions had no effect on aerobic metabolism during severe-intensity exercise or on performance or the recovery of the adrenergic and metabolic responses after repeated-sprint exercise in trained athletes.

Relative contributions of protection motivation theory components in predicting exercise intentions and behavior.

PubMed

Wurtele, S K; Maddux, J E

1987-01-01

A factorial design was employed to test the relative effectiveness of the four cognitive appraisal processes (severity, vulnerability, response efficacy, and self-efficacy) contained in the revised protection motivation theory (PMT). One hundred sixty undergraduate women read persuasive appeals for increasing exercise, which varied on these four dimensions. As predicted, both the vulnerability and self-efficacy variables enhanced intentions to exercise along with similar effects on self-reported exercising. Intentions were predictive of self-reported changes in behavior. The obtained interaction between vulnerability, self-efficacy, and response efficacy suggests that individuals employed a "precaution strategy": They intended to adopt the recommended behavior even though they held weak beliefs about its effectiveness and were not convinced of their at-risk status. These findings are compared to others obtained using the PMT, and the issue of main and interactive effects produced by the model is also addressed.

Physiologic responses during indoor cycling.

PubMed

Battista, Rebecca A; Foster, Carl; Andrew, Jessica; Wright, Glenn; Lucia, Alejandro; Porcari, John P

2008-07-01

During the last decade, there has been active interest in indoor cycling (e.g., spinning) as a method of choreographed group exercise. Recent studies have suggested that exercise intensity during indoor cycling may be quite high and may transiently exceed Vo2max. This study sought to confirm these findings, as the apparent high intensity of indoor cycling has implications for both the efficacy and the risk of indoor cycling as an exercise method. Twenty healthy female students performed an incremental exercise test to define Vo2max and performed 2 videotaped indoor exercise classes lasting 45 minutes and 35 minutes. Vo2, heart rate (HR), and rating of perceived exertion (RPE) were measured during the indoor cycling classes, with Vo2 data integrated in 30-second intervals. The mean %Vo2max during the indoor cycling classes was modest (74 +/- 14% Vo2max and 66 +/- 14%Vo2max, respectively). However, 52% and 35% of the time during the 45- and 35-minute classes was spent at intensities greater than the ventilatory threshold (VT). The HR response indicated that 35% and 38% of the session time was above the HR associated with VT. In 10 of the 40 exercise sessions, there were segments in which the momentary Vo2 exceeded Vo2max observed during incremental testing, and the cumulative time with exercise intensity greater than Vo2max ranged from 0.5 to 14.0 minutes. It can be concluded that although the intensity of indoor cycling in healthy, physically active women is moderate, there are frequent observations of transient values of Vo2 exceeding Vo2max, and a substantial portion of the exercise bouts at intensities greater than VT. As such, the data suggest that indoor cycling must be considered a high-intensity exercise mode of exercise training, which has implications for both efficacy and risk.

Exercise-induced hypertension, cardiovascular events, and mortality in patients undergoing exercise stress testing: a systematic review and meta-analysis.

PubMed

Schultz, Martin G; Otahal, Petr; Cleland, Verity J; Blizzard, Leigh; Marwick, Thomas H; Sharman, James E

2013-03-01

The prognostic relevance of a hypertensive response to exercise (HRE) is ill-defined in individuals undergoing exercise stress testing. The study described here was intended to provide a systematic review and meta-analysis of published literature to determine the value of exercise-related blood pressure (BP) (independent of office BP) for predicting cardiovascular (CV) events and mortality. Online databases were searched for published longitudinal studies reporting exercise-related BP and CV events and mortality rates. We identified for review 12 longitudinal studies with a total of 46,314 individuals without significant coronary artery disease, with total CV event and mortality rates recorded over a mean follow-up of 15.2±4.0 years. After adjustment for age, office BP, and CV risk factors, an HRE at moderate exercise intensity carried a 36% greater rate of CV events and mortality (95% CI, 1.02-1.83, P = 0.039) than that of subjects without an HRE. Additionally, each 10mm Hg increase in systolic BP during exercise at moderate intensity was accompanied by a 4% increase in CV events and mortality, independent of office BP, age, or CV risk factors (95% CI, 1.01-1.07, P = 0.02). Systolic BP at maximal workload was not significantly associated with the outcome of an increased rate of CV, whether analyzed as a categorical (HR=1.49, 95% CI, 0.90-2.46, P = 0.12) or a continuous (HR=1.01, 95% CI, 0.98-1.04, P = 0.53) variable. An HRE at moderate exercise intensity during exercise stress testing is an independent risk factor for CV events and mortality. This highlights the need to determine underlying pathophysiological mechanisms of exercise-induced hypertension.

The effect of exercise intensity and excess postexercise oxygen consumption on postprandial blood lipids in physically inactive men.

PubMed

Littlefield, Laurel A; Papadakis, Zacharias; Rogers, Katie M; Moncada-Jiménez, José; Taylor, J Kyle; Grandjean, Peter W

2017-09-01

Reductions in postprandial lipemia have been observed following aerobic exercise of sufficient energy expenditure. Increased excess postexercise oxygen consumption (EPOC) has been documented when comparing high- versus low-intensity exercise. The contribution of EPOC energy expenditure to alterations in postprandial lipemia has not been determined. The purpose of this study was to evaluate the effects of low- and high-intensity exercise on postprandial lipemia in healthy, sedentary, overweight and obese men (age, 43 ± 10 years; peak oxygen consumption, 31.1 ± 7.5 mL·kg -1 ·min -1 ; body mass index, 31.8 ± 4.5 kg/m 2 ) and to determine the contribution of EPOC to reductions in postprandial lipemia. Participants completed 4 conditions: nonexercise control, low-intensity exercise at 40%-50% oxygen uptake reserve (LI), high-intensity exercise at 70%-80% oxygen uptake reserve (HI), and HI plus EPOC re-feeding (HI+EERM), where the difference in EPOC energy expenditure between LI and HI was re-fed in the form of a sports nutrition bar (Premier Nutrition Corp., Emeryville, Calif., USA). Two hours following exercise participants ingested a high-fat (1010 kcals, 99 g sat fat) test meal. Blood samples were obtained before exercise, before the test meal, and at 2, 4, and 6 h postprandially. Triglyceride incremental area under the curve was significantly reduced following LI, HI, and HI+EERM when compared with nonexercise control (p < 0.05) with no differences between the exercise conditions (p > 0.05). In conclusions, prior LI and HI exercise equally attenuated postprandial triglyceride responses to the test meal. The extra energy expended during EPOC does not contribute significantly to exercise energy expenditure or to reductions in postprandial lipemia in overweight men.

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.

Exercise in claudicants increase or decrease walking ability and the response relates to mitochondrial function.

PubMed

van Schaardenburgh, Michel; Wohlwend, Martin; Rognmo, Øivind; Mattsson, Erney J R

2017-06-07

Exercise of patients with intermittent claudication improves walking performance. Exercise does not usually increase blood flow, but seems to increase muscle mitochondrial enzyme activities. Although exercise is beneficial in most patients, it might be harmful in some. The mitochondrial response to exercise might therefore differ between patients. Our hypothesis was that changes in walking performance relate to changes in mitochondrial function after 8 weeks of exercise. At a subgroup level, negative responders decrease and positive responders increase mitochondrial capacity. Two types of exercise were studied, calf raising and walking (n = 28). We wanted to see whether there were negative and positive responders, independent of type of exercise. Measurements of walking performance, peripheral hemodynamics, mitochondrial respiration and content (citrate synthase activity) were obtained on each patient before and after the intervention period. Multiple linear regression was used to test whether changes in peak walking time relate to mitochondrial function. Subgroups of negative (n = 8) and positive responders (n = 8) were defined as those that either decreased or increased peak walking time following exercise. Paired t test and analysis of covariance was used to test changes within and between subgroups. Changes in peak walking time were related to changes in mitochondrial respiration supported by electron transferring flavoprotein (ETF + CI) P (p = 0.004), complex I (CI + ETF) P (p = 0.003), complex I + complex II (CI + CII + ETF) P (p = 0.037) and OXPHOS coupling efficiency (p = 0.046) in the whole group. Negative responders had more advanced peripheral arterial disease. Mitochondrial respiration supported by electron transferring flavoprotein (ETF + CI) P (p = 0.0013), complex I (CI + ETF) P (p = 0.0005), complex I + complex II (CI + CII + ETF) P (p = 0.011) and electron transfer system capacity (CI + CII + ETF) E (p = 0.021) and OXPHOS coupling efficiency decreased in negative responders (p = 0.0007) after exercise. Positive responders increased citrate synthase activity (p = 0.010). Changes in walking performance seem to relate to changes in mitochondrial function after exercise. Negative responders have more advanced peripheral arterial disease and decrease, while positive responders increase mitochondrial capacity. Trial registration ClinicalTrials.gov ID: NCT023110256.

Summary and results of the joint WMD-DAC/Alameda County bioterrorism response plan exercise.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Manley, Dawn Kataoka; Lipkin, Joel; West, Todd H.

2003-11-01

On June 12,2003, the Alameda County Public Health Department and Sandia National Laboratories/CA jointly conducted an exercise that used a Weapons of Mass Destruction-Decision Analysis Center (WMD-DAC) bioterrorism attack simulation to test the effectiveness of the county's emergency response plan. The exercise was driven by an assumed release (in the vicinity of the Berkeley Marina), and subsequent spread, of a small quantity of aerosolized, weapons-grade anthrax spores. The simulation used several key WMD-DAC capabilities, namely: (1) integration with an atmospheric dispersion model to calculate expected dose levels in the affected areas, (2) a individual-tracking capability for both infected and non-infectedmore » persons as they made decisions, sought treatment, and received prophylaxis drugs, and (3) a user interface that allows exercise participants to affect the scenario evolution and outcome. The analysis of the county's response plan included documenting and reviewing the decisions made by participants during the exercise. Twenty-six local and regional officials representing the health care system, emergency medical services and law enforcement were involved in responding to the simulated attack. The results of this joint effort include lessons learned both by the Alameda County officials regarding implementation of their bioterrorism response plan and by the Sandia representatives about conducting exercises of this type. These observations are reviewed in this report, and they form a basis for providing a better understanding of group/individual decision processes and for identifying effective communication options among decision makers.« less

Cortisol responses to mental stress, exercise, and meals following caffeine intake in men and women.

PubMed

Lovallo, William R; Farag, Noha H; Vincent, Andrea S; Thomas, Terrie L; Wilson, Michael F

2006-03-01

Caffeine elevates cortisol secretion, and caffeine is often consumed in conjunction with exercise or mental stress. The interactions of caffeine and stress on cortisol secretion have not been explored adequately in women. We measured cortisol levels at eight times on days when healthy men and women consumed caffeine (250 mg x 3) and underwent either mental stress or dynamic exercise protocols, followed by a midday meal, in a double blind, placebo-controlled, crossover design. Men and women had similar cortisol levels at the predrug baselines, but they responded differently to mental stress and exercise. The cortisol response to mental stress was smaller in women than in men (p=.003). Caffeine acted in concert with mental stress to further increase cortisol levels (p=.011), the effect was similar in men and women. Exercise alone did not increase cortisol, but caffeine taken before exercise elevated cortisol in both men and women (ps<.05). After a postexercise meal, the women had a larger cortisol response than the men, and this effect was greater after caffeine (p<.01). Cortisol release in response to stress and caffeine therefore appears to be a function of the type of stressor and the sex of the subject. However, repeated caffeine doses increased cortisol levels across the test day without regard to the sex of the subject or type of stressor employed (p<.00001). Caffeine may elevate cortisol by stimulating the central nervous system in men but may interact with peripheral metabolic mechanisms in women.

The creatine kinase response to eccentric exercise with atorvastatin 10 mg or 80 mg.

PubMed

Kearns, Amy K; Bilbie, Cherie L; Clarkson, Priscilla M; White, C Michael; Sewright, Kim A; O'Fallon, Kevin S; Gadarla, Mamatha; Thompson, Paul D

2008-09-01

Hydroxy-methyl-glutaryl co-enzyme A (HMG-CoA) reductase inhibitors or statins are well tolerated by most patients, but can produce a variety of skeletal muscle problems including myalgia, creatine kinase (CK) elevations and clinically important rhabdomyolysis. We have previously demonstrated that the CK response to downhill walking is greater in statin compared to placebo treated subjects. This study examined the CK response to downhill walking in subjects treated with low and high dose of atorvastatin. 79 subjects with LDL cholesterol>100mg/dL were randomly assigned to atorvastatin 10mg (N=42) or 80 mg (N=37) for 5 weeks. Subjects performed a downhill walking exercise during the fifth week of treatment. Leg muscle soreness, plasma CK and CK-MB levels were measured daily for 4 days following the exercise. CK, CK-MB and muscle soreness increased above pre-exercise levels in all subjects after the exercise. There were no differences in the CK, CK-MB or soreness response between the high and low dose treatment groups at any time point. The downhill walking model of muscle injury does not distinguish between high and low dose atorvastatin therapy either because this test is insensitive to differences among statin doses or because there is no difference in muscle injury between these two drug doses with this statin. Clinicians should be aware, however, that exercise can increase CK levels with even low dose statin therapy.

Associations between cardiorespiratory responses to exercise and the C34T AMPD1 gene polymorphism in the HERITAGE Family Study.

PubMed

Rico-Sanz, J; Rankinen, T; Joanisse, D R; Leon, A S; Skinner, J S; Wilmore, J H; Rao, D C; Bouchard, C

2003-07-07

The associations of the C34T polymorphism of the adenosine monophosphate deaminase 1 (AMPD1) gene with cardiorespiratory phenotypes were tested during cycling exercise at absolute and relative power outputs progressing to exhaustion before and after endurance training for 20 wk in the HERITAGE Family Study cohort (n = 779). Since no blacks were mutant homozygotes (TT), only whites were considered for analysis (400 normal homozygotes, CC; 97 heterozygotes, CT; and 6 TT). For sedentary state, cycling at the absolute power output of 50 W resulted in a higher rating of perceived exertion in TT (P < 0.0001). At the relative intensity of 60% of Vo(2 max), stroke volume was lower in TT (P < 0.05). Maximal values for power output, systolic blood pressure, heart rate, Vco(2), and respiratory exchange ratio were lower in TT (P < 0.05). The cardiorespiratory training response at 50 W and at 60% of Vo(2 max) was similar across C34T-AMPD1 genotypes. However, the maximal values for ventilation, Vo(2), and Vco(2) during exercise increased less in TT (P < 0.01). The results indicate that subjects with the TT genotype at the C34T AMPD1 gene have diminished exercise capacity and cardiorespiratory responses to exercise in the sedentary state. Furthermore, the training response of ventilatory phenotypes during maximal exercise is more limited in TT.

Effect of Pharmacologically-Induced Hypovolemia on Aerobic Capacity

NASA Technical Reports Server (NTRS)

Everett, Meghan E.; Lee, S. M. C.; Platts, S. H.

2009-01-01

Decreased peak oxygen consumption (VO2pk) and an elevated exercise heart rate (HR) response are associated with a reduction in plasma volume (PV) after space flight and bed rest, a space flight analog. Reduced VO2pk and submaximal exercise tolerance would negatively impact an astronaut s ability to perform near maximal work that would be required in the event of an emergency. We previously have administered IV furosemide followed by a low salt diet to model PV loss and orthostatic intolerance observed after spaceflight. Purpose: To determine whether a pharmacologically-induced reduction in PV results in decreased VO2pk and elevated exercise HR response. Methods: Six subjects (5M, 1F) performed two graded peak cycle tests (work rate increased by 35 or 50 W every 3 min), once while normovolemic and once while hypovolemic. HR and expired respiratory gases were continuously measured. To induce hypovolemia, subjects were administered a single dose of IV furosemide (0.5 mg.kg-1) 30 hr before exercise testing and then consumed a low-salt diet (10 mEq.d(sup -1)). PV was measured using carbon monoxide rebreathing. Exercise HR and VO2 responses were quantified as the area under the curve (AUC) calculated over each quartile of the peak test, based on test time in the hypovolemia condition. Paired t-tests were used to test for differences in PV, VO2pk, and peak HR between conditions. Repeated-measures ANOVAs were used to test for differences in AUC between conditions. Results: PV (3.32+/-0.12 vs. 2.77+/-0.16 L, p<0.05) and VO2pk (3.30+/-0.67 vs. 2.90+/-0.57 L.min(sup -1), p<0.05) were lower during hypovolemia than during normovolemia, but peak HR was not different (187+/-5 vs. 187+/-5 bpm). The AUC for VO2 and HR was different (p<0.05) between conditions only in the highest quartile: HR was 4% higher and VO2 was 5% lower during the hypovolemia condition. Conclusion: The mean difference in VO2pk (-12%) between normovolemia and hypovolemia was similar to the mean difference in PV (-17%). Similar decreases in PV and VO2pk have been observed following short duration space flight, suggesting that pharmacologically-induced PV loss can be used to model microgravity-induced reductions in VO2pk.

Exercise-Induced Changes in the Cortical Bone of Growing Mice Are Bone and Gender Specific

PubMed Central

Wallace, Joseph M.; Rajachar, Rupak M.; Allen, Matthew R.; Bloomfield, Susan A.; Robey, Pamela G.; Young, Marian F.; Kohn, David H.

2009-01-01

Fracture risk and mechanical competence of bone are functions of bone mass and tissue quality, which in turn are dependent on the bone’s mechanical environment. Male mice have a greater response to non weight-bearing exercise than females, resulting in larger, stronger bones compared with control animals. The aim of this study was to test the hypothesis that short-term weight-bearing running during growth (21 days starting at 8 weeks of age; 30 minutes/day; 12 meters/minute; 5° incline; 7 days/week) would similarly have a greater impact on cross sectional geometry and mechanical competence in the femora and tibiae of male mice versus females. Based on the orientation of the legs during running and the proximity of the tibia to the point of impact, this response was hypothesized to be greatest in the tibia. Exercise-related changes relative to controls were assayed by four-point bending tests, while volumetric bone mineral density and cross-sectional geometry were also assessed. The response to running was bone and gender-specific, with male tibiae demonstrating the greatest effects. In male tibiae, periosteal perimeter, endocortical perimeter, cortical area, medial-lateral width and bending moment of inertia increased versus control mice suggesting that while growth is occurring in these mice between 8 and 11 weeks of age, exercise accelerated this growth resulting in a greater increase in bone tissue over the 3 weeks of the study. Exercise increased tissue-level strain-to-failure and structural post-yield deformation in the male tibiae, but these post-yield benefits came at the expense of decreased yield deformation, structural and tissue-level yield strength and tissue-level ultimate strength. These results suggest that exercise superimposed upon growth accelerated growth-related increases in tibial cross-sectional dimensions. Exercise also influenced the quality of this forming bone, significantly impacting structural and tissue-level mechanical properties. PMID:17240210

A comparative study of two protocols for treadmill walking exercise testing in ambulating subjects with incomplete spinal cord injury.

PubMed

Lundgaard, E; Wouda, M F; Strøm, V

2017-10-01

This is a comparative study of two exercise testing protocols. The objective of this study was to compare maximal oxygen uptake (VO 2 max) and achieved criteria for maximal exercise testing between the Sunnaas Protocol-a newly designed treadmill exercise test protocol-and the Modified Bruce Protocol in persons with incomplete spinal cord injury (SCI). This study was conducted in Sunnaas Rehabilitation Hospital, Norway. Twenty persons (19 men) with incomplete SCI (AIS D) capable of ambulating without assistive devices performed two treadmill walking exercise tests (Sunnaas Protocol and Modified Bruce Protocol) until exhaustion 1-3 days apart. The key differences between the protocols are the smaller increments in speed and shorter duration on each workload in the Sunnaas Protocol. Cardiovascular responses were measured continuously throughout both tests. The subjects exhibited statistically significantly higher VO 2 max when using the Sunnaas Protocol (37.1±9.9 vs 35.4±9.8 ml kg -1  min -1 , P=0.01), with a mean between-test difference of 1.8 ml kg -1  min -1 (95% confidence interval: 0.49-3.16). There was no significant difference in mean maximal heart rate (HR max). Nineteen (95%) subjects achieved at least three of the four criteria for maximal oxygen uptake using the Sunnaas Protocol. Thirteen (65%) subjects achieved at least three of the criteria using a Modified Bruce protocol. The small differences in both VO 2 max and achieved criteria in favor of the Sunnaas Protocol suggest that it could be a useful alternative treadmill exercise test protocol for ambulating persons with incomplete SCI.

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.

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.

Oncology care provider perspectives on exercise promotion in people with cancer: an examination of knowledge, practices, barriers, and facilitators.

PubMed

Nadler, Michelle; Bainbridge, Daryl; Tomasone, Jennifer; Cheifetz, Oren; Juergens, Rosalyn A; Sussman, Jonathan

2017-07-01

Despite the reported benefits of physical activity in alleviating the impact of cancer and its treatments, oncology care providers (OCPs) are not routinely discussing exercise with their patients, suggesting a knowledge to action gap. We sought to determine OCP's knowledge, beliefs, barriers, and facilitators to exercise discussion. A survey was administered to OCPs at the cancer center in Hamilton, Ontario. Questions comprised of demographics, knowledge and beliefs regarding exercise guidelines, and barriers and facilitators to exercise discussion. Analysis of survey responses was descriptive. Pearson's chi-squared test was used to examine select associations. There were 120 respondents (61% response rate) representing a diversity of professions. Approximately, 80% of OCPs were not aware of any exercise guidelines in cancer and self-reported poor knowledge on when, how, and which patients to refer to exercise programs. OCPs who reported meeting Canada's Physical Activity guidelines were significantly more likely to identify correct guidelines (p = 0.023) and to report good knowledge on how to provide exercise counseling (p = 0.014). Across OCP groups, barriers to exercise discussion included poor knowledge, lack of time, and safety concerns. Most felt that educational sessions and having an exercise specialist on the clinical team would be beneficial. OCPs have low knowledge regarding exercise counseling, but believe that discussing exercise is a multidisciplinary task and expressed a desire for further training. Interventions will require a multi-pronged approach including education for OCPs and guidance on assessment for exercise safety.

Altered Blood Flow Response to Small Muscle Mass Exercise in Cancer Survivors Treated With Adjuvant Therapy.

PubMed

Didier, Kaylin D; Ederer, Austin K; Reiter, Landon K; Brown, Michael; Hardy, Rachel; Caldwell, Jacob; Black, Christopher; Bemben, Michael G; Ade, Carl J

2017-02-07

Adjuvant cancer treatments have been shown to decrease cardiac function. In addition to changes in cardiovascular risk, there are several additional functional consequences including decreases in exercise capacity and increased incidence of cancer-related fatigue. However, the effects of adjuvant cancer treatment on peripheral vascular function during exercise in cancer survivors have not been well documented. We investigated the vascular responses to exercise in cancer survivors previously treated with adjuvant cancer therapies. Peripheral vascular responses were investigated in 11 cancer survivors previously treated with adjuvant cancer therapies (age 58±6 years, 34±30 months from diagnosis) and 9 healthy controls group matched for age, sex, and maximal voluntary contraction. A dynamic handgrip exercise test at 20% maximal voluntary contraction was performed with simultaneous measurements of forearm blood flow and mean arterial pressure. Forearm vascular conductance was calculated from forearm blood flow and mean arterial pressure. Left ventricular ejection time index (LVETi) was derived from the arterial pressure wave form. Forearm blood flow was attenuated in cancer therapies compared to control at 20% maximal voluntary contraction (189.8±53.8 vs 247.9±80.3 mL·min -1 , respectively). Forearm vascular conductance was not different between groups at rest or during exercise. Mean arterial pressure response to exercise was attenuated in cancer therapies compared to controls (107.8±10.8 vs 119.2±16.2 mm Hg). LEVTi was lower in cancer therapies compared to controls. These data suggest an attenuated exercise blood flow response in cancer survivors ≈34 months following adjuvant cancer therapy that may be attributed to an attenuated increase in mean arterial pressure. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

Potential neurobiological benefits of exercise in chronic pain and posttraumatic stress disorder: Pilot study.

PubMed

Scioli-Salter, Erica; Forman, Daniel E; Otis, John D; Tun, Carlos; Allsup, Kelly; Marx, Christine E; Hauger, Richard L; Shipherd, Jillian C; Higgins, Diana; Tyzik, Anna; Rasmusson, Ann M

2016-01-01

This pilot study assessed the effects of cardiopulmonary exercise testing and cardiorespiratory fitness on plasma neuropeptide Y (NPY), allopregnanolone and pregnanolone (ALLO), cortisol, and dehydroepiandrosterone (DHEA), and their association with pain sensitivity. Medication-free trauma-exposed participants were either healthy (n = 7) or experiencing comorbid chronic pain/posttraumatic stress disorder (PTSD) (n = 5). Peak oxygen consumption (VO2) during exercise testing was used to characterize cardiorespiratory fitness. Peak VO2 correlated with baseline and peak NPY levels (r = 0.66, p < 0.05 and r = 0.69, p < 0.05, respectively), as well as exercise-induced changes in ALLO (r = 0.89, p < 0.001) and peak ALLO levels (r = 0.71, p < 0.01). NPY levels at the peak of exercise correlated with pain threshold 30 min after exercise (r = 0.65, p < 0.05), while exercise-induced increases in ALLO correlated with pain tolerance 30 min after exercise (r = 0.64, p < 0.05). In contrast, exercise-induced changes in cortisol and DHEA levels were inversely correlated with pain tolerance after exercise (r = -0.69, p < 0.05 and r = -0.58, p < 0.05, respectively). These data suggest that cardiorespiratory fitness is associated with higher plasma NPY levels and increased ALLO responses to exercise, which in turn relate to pain sensitivity. Future work will examine whether progressive exercise training increases cardiorespiratory fitness in association with increases in NPY and ALLO and reductions in pain sensitivity in chronic pain patients with PTSD.

A practical clinical approach to utilize cardiopulmonary exercise testing in the evaluation and management of coronary artery disease: a primer for cardiologists

PubMed Central

Chaudhry, Sundeep; Arena, Ross; Bhatt, Deepak L.; Verma, Subodh; Kumar, Naresh

2018-01-01

Purpose of review There is growing clinical interest for the use of cardiopulmonary exercise testing (CPET) to evaluate patients with or suspected coronary artery disease (CAD). With mounting evidence, this concise review with relevant teaching cases helps to illustrate how to integrate CPET data into real world patient care. Recent findings CPET provides a novel and purely physiological basis to identify cardiac dysfunction in symptomatic patients with both obstructive-CAD and nonobstructive-CAD (NO-CAD). In many cases, abnormal cardiac response on CPET may be the only objective evidence of potentially undertreated ischemic heart disease. When symptomatic patients have NO-CAD on coronary angiogram, they are still at increased risk for cardiovascular events. This problem appears to be more common in women than men and may warrant more aggressive risk factor modification. As the main intervention is lifestyle (diet, smoking cessation, exercise) and medical therapy (statins, angiotensin-converting enzyme inhibitors, beta-blockers), serial CPET testing enables close surveillance of cardiovascular function and is responsive to clinical status. Summary CPET can enhance outpatient evaluation and management of CAD. Diagnostically, it can help to identify physiologically significant obstructive-CAD and NO-CAD in patients with normal routine cardiac testing. CPET may be of particular value in symptomatic women with NO-CAD. Prognostically, precise quantification of improvements in exercise capacity may help to improve long-term lifestyle and medication adherence for this chronic condition. PMID:29240566

Ratings of Perceived Exertion of ACSM Exercise Guidelines in Individuals Varying in Aerobic Fitness

ERIC Educational Resources Information Center

Kaufman, Christopher; Berg, Kris; Noble, John; Thomas, James

2006-01-01

The physiological responses of high (HF) and low fit (LF) individuals at given perceived exercise intensities were compared to ranges provided by the American College of Sports Medicine (ACSM). Participants were 7 LF and 8 HF men between the ages of 22 and 26 years. All participants performed a maximum oxygen uptake and lactate threshold test and…

Acute pulmonary effects of nitrogen dioxide exposure during exercise in competitive athletes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, S.U.; Koenig, J.Q.; Pierson, W.E.

The acute pulmonary responses of athletes after short-term exposure to ambient concentrations of NO{sub 2} during heavy exercise have been examined. Intercollegiate male athletes were screened for history of cardiac disease, respiratory disease, allergic conditions and extensive exposure to pollutants. After completion of serum IgE level determination, exercise tolerance test and methacholine challenge test with normal results, nine healthy subjects 18 to 23 years of age were exposed to filtered air and to 0.18 and 0.30 ppm NO{sub 2} for 30 min on different days while exercising on a treadmill. Pulmonary function parameters were measured before and after each exposure.more » In this study, no statistically significant changes were observed in FEV1, RT PEFR, and Vmax50% after exposure to 0.18 and 0.30 ppm NO{sub 2}. For these selected healthy athletes, short-term exposure to ambient NO{sub 2} levels during heavy exercise does not affect adversely the pulmonary function.« less

Effect of long-term training and acute physical exercise on red cell 2,3-diphosphoglycerate.

PubMed

Remes, K; Vuopio, P; Härkönen, M

1979-11-01

A statistically significant 10% increase (p less than 0.005) in mean red cell 2,3-diphosphoglycerate (2,3-DPG) concentration, concomitantly with a mean 16% increase (p less than 0.001) in the predicted maximal oxygen uptake (VO2max) was observed in 29 recruits, who were studied during 6 months of physical training in military service. The increase in 2,3-DPG was higher, the lower the initial 2,3-DPG and VO2max levels. The mean initial 2,3-DPG level was higher in the subjects with a higher initial VO2max. A strenuous but highly aerobic 21-km marching exercise elicited a mean 9% increase (p less than 0.005) in red cell 2,3-DPG concentration. A significantly greater response of 2,3-DPG to marching exercise was observed in subjects with a lower pre-test VO2max than in those with a higher pre-test VO2max. During another more competitive march 2,3-DPG remained almost unchanged and was associated with a tendency towards a negative correlation with the acccompanying lactate response (r = -0.60, p less than 0.05). Red cell 2,3-DPG response to a standardized exercise is considered to be a suitable indicator for evaluating the effect of training on an individual.

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.

Influence of late-life exposure to environmental enrichmentor exercise on hippocampal function and CA1 senescent physiology

PubMed Central

Kumar, A.; Rani, A.; Tchigranova, Olga; Lee, Wei-Hua; Foster, T.C.

2011-01-01

Aged (20–22 months) male Fischer 344 rats were randomly assigned to sedentary (A-SED), environmentally enriched (A-ENR) or exercise (A-EX) conditions. After 10–12 weeks of differential experience, the three groups of aged rats and young sedentary controls were tested for physical and cognitive function. Spatial discrimination learning and memory consolidation, tested on the water maze, were enhanced in A-ENR compared to A-SED. A-EX exhibited improved and impaired performance on the cue and spatial task, respectively. Impaired spatial learning in A-EX was likely due to a bias in response selection associated with exercise training, as object recognition memory improved for A-EX rats. An examination of senescent hippocampal physiology revealed that enrichment and exercise reversed age-related changes in long-term depression (LTD) and long-term potentiation (LTP). Rats in the enrichment group exhibited an increase in cell excitability compared to the other two groups of aged animals. The results indicate that differential experience biased the selection of a spatial or a response strategy and factors common across the two conditions, such as increased hippocampal activity associated with locomotion, contribute to reversal of senescent synaptic plasticity. PMID:21820213

Influence of a high-intensity interval training session on peripheral and central blood pressure at rest and during stress testing in healthy individuals.

PubMed

Ketelhut, Sascha; Milatz, Florian; Heise, Walter; Ketelhut, Reinhard G

2016-09-01

Regular physical activity is known to reduce arterial pressure (BP). In a previous investigation, we could prove that even a single bout of moderate-intensity continuous exercise (MICE) causes a prolonged reduction in BP. Whether high-intensity interval training (HIIT) has a favourable influence on BP, and therefore may be followed subjects and methods by a prolonged BP reduction, should be examined on the basis of blood pressure response after exercise and during a subsequent stress test. In 39 healthy men (aged 34 ± 8 years, BMI 24 ± 2), peripheral and central BP were measured noninvasively at rest and at the end of a 2-min cold pressor test (CPT) using a Mobil-O-Graph (24 PWA monitor, IEM). Following HIIT (6 x 1 min at 98% of the previously determined maximum wattage, 4-min rest between intervals) BP was measured again throughout 60 min of rest and thereafter during a CPT. The results were compared with those obtained before HIIT. Similar to MICE, peripheral and central BPs were significantly (p < 0.05) lower 45 min after HIIT. When analysing peripheral BP during a CPT before and after exercise, significantly lower systolic (p < 0.001) and diastolic (p = 0.008) pressures were established after HIIT. This was true for systolic (p = 0.002) and diastolic (p = 0.006) central BP as well. Although there were no more significant differences between pressures at rest before and 60 min after exercise, the increase in peripheral systolic pressure due to CPT was significantly slower after HIIT (p = 0.019) when compared with BP during CPT before exercise. This was true for central systolic BP as well (p = 0.017). HIIT leads to a BP reduction, which can still be detected up to 45 min after completion of the training. Even 60 min after exercise, pressures during a CPT showed a reduced augmentation, indicating an attenuated hemodynamic response to stress testing after HIIT.

Exercise reinforcement, stress, and β-endorphins: an initial examination of exercise in anabolic-androgenic steroid dependence.

PubMed

Hildebrandt, Tom; Shope, Sydney; Varangis, Eleanna; Klein, Diane; Pfaff, Donald W; Yehuda, Rachel

2014-06-01

Anabolic-androgenic steroids (AASs) are abused primarily in the context of intense exercise and for the purposes of increasing muscle mass as opposed to drug-induced euphoria. AASs also modulate the HPA axis and may increase the reinforcing value of exercise through changes to stress hormone and endorphin release. To test this hypothesis, 26 adult males drawn from a larger study on AAS use completed a progressive ratio task designed to examine the reinforcing value of exercise relative to financial reinforcer. Sixteen experienced and current users (8 on-cycle, 8 off-cycle) and 10 controls matched on quantity×frequency of exercise, age, and education abstained from exercise for 24 h prior to testing and provided 24-h cortisol, plasma cortisol, ACTH, β-endorphin samples, and measures of mood, compulsive exercise, and body image. Between group differences indicated that on-cycle AAS users had the highest β-endorphin levels, lowest cortisol levels, higher ACTH levels than controls. Conversely, off-cycle AAS users had the highest cortisol and ACTH levels, but the lowest β-endorphin levels. Exercise value was positively correlated with β-endorphin and symptoms of AAS dependence. The HPA response to AASs may explain why AASs are reinforcing in humans and exercise may play a key role in the development of AAS dependence. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

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.

Effects of aerobic training intensity on resting, exercise and post-exercise blood pressure, heart rate and heart-rate variability.

PubMed

Cornelissen, V A; Verheyden, B; Aubert, A E; Fagard, R H

2010-03-01

We aimed to investigate the effects of endurance training intensity (1) on systolic blood pressure (SBP) and heart rate (HR) at rest before exercise, and during and after a maximal exercise test; and (2) on measures of HR variability at rest before exercise and during recovery from the exercise test, in at least 55-year-old healthy sedentary men and women. A randomized crossover study comprising three 10-week periods was performed. In the first and third period, participants exercised at lower or higher intensity (33% or 66% of HR reserve) in random order, with a sedentary period in between. Training programmes were identical except for intensity, and were performed under supervision thrice for 1 h per week. The results show that in the three conditions, that is, at rest before exercise, during exercise and during recovery, we found endurance training at lower and higher intensity to reduce SBP significantly (P<0.05) and to a similar extent. Further, SBP during recovery was, on average, not lower than at rest before exercise, and chronic endurance training did not affect the response of SBP after an acute bout of exercise. The effect of training on HR at rest, during exercise and recovery was more pronounced (P<0.05) with higher intensity. Finally, endurance training had no significant effect on sympathovagal balance. In conclusion, in participants at higher age, both training programmes exert similar effects on SBP at rest, during exercise and during post-exercise recovery, whereas the effects on HR are more pronounced after higher intensity training.

Benefits of pulmonary rehabilitation in patients with COPD and normal exercise capacity.

PubMed

Lan, Chou-Chin; Chu, Wen-Hua; Yang, Mei-Chen; Lee, Chih-Hsin; Wu, Yao-Kuang; Wu, Chin-Pyng

2013-09-01

Pulmonary rehabilitation (PR) is beneficial for patients with COPD, with improvement in exercise capacity and health-related quality of life. Despite these overall benefits, the responses to PR vary significantly among different individuals. It is not clear if PR is beneficial for patients with COPD and normal exercise capacity. We aimed to investigate the effects of PR in patients with normal exercise capacity on health-related quality of life and exercise capacity. Twenty-six subjects with COPD and normal exercise capacity were studied. All subjects participated in 12-week, 2 sessions per week, hospital-based, out-patient PR. Baseline and post-PR status were evaluated by spirometry, the St George's Respiratory Questionnaire, cardiopulmonary exercise test, respiratory muscle strength, and dyspnea scores. The mean FEV1 in the subjects was 1.29 ± 0.47 L/min, 64.8 ± 23.0% of predicted. After PR there was significant improvement in maximal oxygen uptake and work rate. Improvements in St George's Respiratory Questionnaire scores of total, symptoms, activity, and impact were accompanied by improvements of exercise capacity, respiratory muscle strength, maximum oxygen pulse, and exertional dyspnea scores (all P < .05). There were no significant changes in pulmonary function test results (FEV1, FVC, and FEV1/FVC), minute ventilation, breathing frequency, or tidal volume at rest or exercise after PR. Exercise training can result in significant improvement in health-related quality of life, exercise capacity, respiratory muscle strength, and exertional dyspnea in subjects with COPD and normal exercise capacity. Exercise training is still indicated for patients with normal exercise capacity.

Moderate endurance exercise in patients with sickle cell anaemia: effects on oxidative stress and endothelial activation.

PubMed

Faes, Camille; Balayssac-Siransy, Edwige; Connes, Philippe; Hivert, Ludovic; Danho, Clotaire; Bogui, Pascal; Martin, Cyril; Pialoux, Vincent

2014-01-01

Very few studies have investigated the effects of exercise on the biological parameters involved in vaso-occlusive events in sickle cell anaemia (SCA). The aim of this study was to test how a mild-moderate endurance exercise modulates oxidative stress, nitric oxide bioavailability and endothelial activation in SCA patients and healthy individuals. Eleven patients with SCA and 15 healthy subjects completed a 20-min duration submaximal cycling exercise at ≈45 Watts. Plasma markers of oxidative stress, antioxidant activity, endothelial activation and nitric oxide bioavailability were investigated before and after the exercise. Nitric oxide levels, anti-oxidant capacity, soluble (s)E-selectin and sP-selectin did not change in response to this exercise. Except for the malondialdehyde levels, which increased in the two groups, the other markers of oxidative stress remained unchanged in both groups in response to exercise. Soluble vascular cell adhesion molecule 1 levels were increased at the end of exercise in both groups. sL-selectin decreased and soluble intercellular adhesion molecule 1 increased with exercise in SCA patients only. The present data suggest that patients with SCA may undertake mild-moderate physical activities without any acute clinical complications, but care should be taken because oxidative stress and endothelial activation significantly increased in some patients. © 2013 John Wiley & Sons Ltd.

Habitual exercise is associated with cognitive control and cognitive reappraisal success.

PubMed

Giles, Grace E; Cantelon, Julie A; Eddy, Marianna D; Brunyé, Tad T; Urry, Heather L; Mahoney, Caroline R; Kanarek, Robin B

2017-12-01

Habitual exercise is associated with enhanced domain-general cognitive control, such as inhibitory control, selective attention, and working memory, all of which rely on the frontal cortex. However, whether regular exercise is associated with more specific aspects of cognitive control, such as the cognitive control of emotion, remains relatively unexplored. The present study employed a correlational design to determine whether level of habitual exercise was related to performance on the Stroop test measuring selective attention and response inhibition, the cognitive reappraisal task measuring cognitive reappraisal success, and associated changes in prefrontal cortex (PFC) oxygenation using functional near-infrared spectroscopy. 74 individuals (24 men, 50 women, age 18-32 years) participated. Higher habitual physical activity was associated with lower Stroop interference (indicating greater inhibitory control) and enhanced cognitive reappraisal success. Higher habitual exercise was also associated with lower oxygenated hemoglobin (O 2 Hb) in the PFC in response to emotional information. However, NIRS data indicated that exercise was not associated with cognitive control-associated O 2 Hb in the PFC. Behaviorally, the findings support and extend the previous findings that habitual exercise relates to more successful cognitive control of neutral information and cognitive reappraisal of emotional information. Future research should explore whether habitual exercise exerts causal benefits to cognitive control and PFC oxygenation, as well as isolate specific cognitive control processes sensitive to change through habitual exercise.

Proinflammatory cytokines correlate with early exercise attenuating anxiety-like behavior after cerebral ischemia.

PubMed

Zhang, Qi; Zhang, Jingjun; Yan, Yuzhong; Zhang, Pengyue; Zhang, Wei; Xia, Rong

2017-11-01

Stroke may cause neuropsychiatric problems, which have negative effects on cognitive functions and behavior. Exercise plays an important role in reducing the occurrence and development of stroke, the concrete mechanism is not fully clarified. In this study, we attempted to determine whether early treadmill exercise attenuates anxiety-like behavior by regulation of inflammation after brain ischemia. We subjected adult male rats to middle cerebral artery occlusion (MCAO) for 90 min and trained rats started to run on a treadmill from postoperative day 1 to day 14. The effects of treadmill on cognitive functions, anxiety-like behavior, and immune activation were analyzed by Morris water maze test, open field test, elevated plus maze test, and enzyme-linked immunosorbent assay. Early treadmill exercise significantly improved cognitive function, alleviated anxiety-like behavior in ischemic rats model; this improvement was associated with significantly decreased activation of astrocytes and microglia cells and proinflammatory markers (platelet-activating factor [PAF], interleukin-6 [IL-6], tumor necrosis factor-alpha [TNF-α], intercellular adhesion molecule-1 [ICAM-1], and vascular cell adhesion molecule-1 [VCAM-1]). Our results indicated that early treadmill exercise attenuated anxiety-like behavior by decreasing inflammation response, exercise conferred a great benefit of attenuating anxiety-like behavior via anti-inflammatory treatment may prove to be a novel neuroprotective strategy for stroke.

Automatic evaluations and exercise setting preference in frequent exercisers.

PubMed

Antoniewicz, Franziska; Brand, Ralf

2014-12-01

The goals of this study were to test whether exercise-related stimuli can elicit automatic evaluative responses and whether automatic evaluations reflect exercise setting preference in highly active exercisers. An adapted version of the Affect Misattribution Procedure was employed. Seventy-two highly active exercisers (26 years ± 9.03; 43% female) were subliminally primed (7 ms) with pictures depicting typical fitness center scenarios or gray rectangles (control primes). After each prime, participants consciously evaluated the "pleasantness" of a Chinese symbol. Controlled evaluations were measured with a questionnaire and were more positive in participants who regularly visited fitness centers than in those who reported avoiding this exercise setting. Only center exercisers gave automatic positive evaluations of the fitness center setting (partial eta squared = .08). It is proposed that a subliminal Affect Misattribution Procedure paradigm can elicit automatic evaluations to exercising and that, in highly active exercisers, these evaluations play a role in decisions about the exercise setting rather than the amounts of physical exercise. Findings are interpreted in terms of a dual systems theory of social information processing and behavior.

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.

Discriminative validity of metabolic and workload measurements for identifying people with chronic fatigue syndrome.

PubMed

Snell, Christopher R; Stevens, Staci R; Davenport, Todd E; Van Ness, J Mark

2013-11-01

Reduced functional capacity and postexertion fatigue after physical activity are hallmark symptoms of chronic fatigue syndrome (CFS) and may even qualify for biomarker status. That these symptoms are often delayed may explain the equivocal results for clinical cardiopulmonary exercise testing in people with CFS. Test reproducibility in people who are healthy is well documented. Test reproducibility may not be achievable in people with CFS because of delayed symptoms. The objective of this study was to determine the discriminative validity of objective measurements obtained during cardiopulmonary exercise testing to distinguish participants with CFS from participants who did not have a disability but were sedentary. A prospective cohort study was conducted. Gas exchange data, workloads, and related physiological parameters were compared in 51 participants with CFS and 10 control participants, all women, for 2 maximal exercise tests separated by 24 hours. Multivariate analysis showed no significant differences between control participants and participants with CFS for test 1. However, for test 2, participants with CFS achieved significantly lower values for oxygen consumption and workload at peak exercise and at the ventilatory or anaerobic threshold. Follow-up classification analysis differentiated between groups with an overall accuracy of 95.1%. Only individuals with CFS who were able to undergo exercise testing were included in this study. Individuals who were unable to meet the criteria for maximal effort during both tests, were unable to complete the 2-day protocol, or displayed overt cardiovascular abnormalities were excluded from the analysis. The lack of any significant differences between groups for the first exercise test would appear to support a deconditioning hypothesis for CFS symptoms. However, the results from the second test indicated the presence of CFS-related postexertion fatigue. It might be concluded that a single exercise test is insufficient to reliably demonstrate functional impairment in people with CFS. A second test might be necessary to document the atypical recovery response and protracted fatigue possibly unique to CFS, which can severely limit productivity in the home and workplace.

10 CFR 72.32 - Emergency Plan.

Code of Federal Regulations, 2013 CFR

2013-01-01

... emergencies. Radiological/Health Physics, Medical, and Fire drills shall be conducted annually. Semiannual... onsite exercises to test response to simulated emergencies. Radiological/Health Physics, Medical, and...

10 CFR 72.32 - Emergency Plan.

Code of Federal Regulations, 2014 CFR

2014-01-01

... emergencies. Radiological/Health Physics, Medical, and Fire drills shall be conducted annually. Semiannual... onsite exercises to test response to simulated emergencies. Radiological/Health Physics, Medical, and...

10 CFR 72.32 - Emergency Plan.

Code of Federal Regulations, 2011 CFR

2011-01-01

... emergencies. Radiological/Health Physics, Medical, and Fire drills shall be conducted annually. Semiannual... onsite exercises to test response to simulated emergencies. Radiological/Health Physics, Medical, and...

10 CFR 72.32 - Emergency Plan.

Code of Federal Regulations, 2012 CFR

2012-01-01

... emergencies. Radiological/Health Physics, Medical, and Fire drills shall be conducted annually. Semiannual... onsite exercises to test response to simulated emergencies. Radiological/Health Physics, Medical, and...

Biomarkers of peripheral muscle fatigue during exercise

PubMed Central

2012-01-01

Background Biomarkers of peripheral muscle fatigue (BPMFs) are used to offer insights into mechanisms of exhaustion during exercise in order to detect abnormal fatigue or to detect defective metabolic pathways. This review aims at describing recent advances and future perspectives concerning the most important biomarkers of muscle fatigue during exercise. Results BPMFs are classified according to the mechanism of fatigue related to adenosine-triphosphate-metabolism, acidosis, or oxidative-metabolism. Muscle fatigue is also related to an immunological response. impaired calcium handling, disturbances in bioenergetic pathways, and genetic responses. The immunological and genetic response may make the muscle susceptible to fatigue but may not directly cause muscle fatigue. Production of BPMFs is predominantly dependent on the type of exercise. BPMFs need to change as a function of the process being monitored, be stable without appreciable diurnal variations, correlate well with exercise intensity, and be present in detectable amounts in easily accessible biological fluids. The most well-known BPMFs are serum lactate and interleukin-6. The most widely applied clinical application is screening for defective oxidative metabolism in mitochondrial disorders by means of the lactate stress test. The clinical relevance of most other BPMFs, however, is under debate, since they often depend on age, gender, physical fitness, the energy supply during exercise, the type of exercise needed to produce the BPMF, and whether healthy or diseased subjects are investigated. Conclusions Though the role of BPMFs during fatigue is poorly understood, measuring BPMFs under specific, standardised conditions appears to be helpful for assessing biological states or processes during exercise and fatigue. PMID:23136874

Cardiopulmonary Exercise Testing in Adult Congenital Heart Disease.

PubMed

Mantegazza, Valentina; Apostolo, Anna; Hager, Alfred

2017-07-01

Recently, the number of patients with congenital heart diseases reaching adulthood has been progressively increasing in developed countries, and new issues are emerging: the evaluation of their capacity to cope with physical activity and whether this knowledge can be used to optimize medical management. A symptom-limited cardiopulmonary exercise test has proven to be an essential tool, because it can objectively evaluate the functional cardiovascular capacity of these patients, identify the pathological mechanisms of the defect (circulatory failure, shunts, and/or pulmonary hypertension), and help prescribe an individualized rehabilitation program when needed. The common findings on cardiopulmonary exercise testing in patients with congenital heart diseases are a reduced peak [Formula: see text]o 2 , an early anaerobic threshold, a blunted heart rate response, a reduced increase of Vt, and an increased [Formula: see text]e/[Formula: see text]co 2 . All these measures suggest common pathophysiological abnormalities: (1) a compromised exercise capacity from anomalies affecting the heart, vessels, lungs, or muscles; (2) chronotropic incompetence secondary to cardiac autonomic dysfunction or β-blockers and antiarrhythmic therapy; and (3) ventilatory inefficiency caused by left-heart failure with pulmonary congestion, pulmonary hypertension, pulmonary obstructive vascular disease, or cachexia. Most of these variables also have prognostic significance. For these patients, cardiopulmonary exercise testing allows evaluation and decisions affecting lifestyle and therapeutic interventions.

An index for breathlessness and leg fatigue.

PubMed

Borg, E; Borg, G; Larsson, K; Letzter, M; Sundblad, B-M

2010-08-01

The features of perceived symptoms causing discontinuation of strenuous exercise have been scarcely studied. The aim was to characterize the two main symptoms causing the discontinuation of heavy work in healthy persons as well as describe the growth of symptoms during exercise. Breathlessness (b) and leg fatigue (l) were assessed using the Borg CR10 Scale and the Borg CR100 (centiMax) Scale, during a standardized exercise test in 38 healthy subjects (24-71 years). The b/l-relationships were calculated for terminal perceptions (ERI(b/l)), and the growth of symptoms determined by power functions for the whole test, as well as by growth response indexes (GRI). This latter index was constructed as a ratio between power levels corresponding to a very strong and a moderate perception. In the majority (71%) of the test subjects, leg fatigue was the dominant symptom at the conclusion of exercise (P<0.001) and the b/l ratio was 0.77 (CR10) and 0.75 (CR100), respectively. The GRI for breathlessness and leg fatigue was similar, with good correlations between GRI and the power function exponent (P<0.005). In healthy subjects, leg fatigue is the most common cause for discontinuing an incremental exercise test. The growth functions for breathlessness and leg fatigue during work are, however, almost parallel.

Disease resistance is related to inherent swimming performance in Atlantic salmon.

PubMed

Castro, Vicente; Grisdale-Helland, Barbara; Jørgensen, Sven M; Helgerud, Jan; Claireaux, Guy; Farrell, Anthony P; Krasnov, Aleksei; Helland, Ståle J; Takle, Harald

2013-01-21

Like humans, fish can be classified according to their athletic performance. Sustained exercise training of fish can improve growth and physical capacity, and recent results have documented improved disease resistance in exercised Atlantic salmon. In this study we investigated the effects of inherent swimming performance and exercise training on disease resistance in Atlantic salmon.Atlantic salmon were first classified as either poor or good according to their swimming performance in a screening test and then exercise trained for 10 weeks using one of two constant-velocity or two interval-velocity training regimes for comparison against control trained fish (low speed continuously). Disease resistance was assessed by a viral disease challenge test (infectious pancreatic necrosis) and gene expression analyses of the host response in selected organs. An inherently good swimming performance was associated with improved disease resistance, as good swimmers showed significantly better survival compared to poor swimmers in the viral challenge test. Differences in mortalities between poor and good swimmers were correlated with cardiac mRNA expression of virus responsive genes reflecting the infection status. Although not significant, fish trained at constant-velocity showed a trend towards higher survival than fish trained at either short or long intervals. Finally, only constant training at high intensity had a significant positive effect on fish growth compared to control trained fish. This is the first evidence suggesting that inherent swimming performance is associated with disease resistance in fish.

Carotid Baroreflex Function During Prolonged Exercise

NASA Technical Reports Server (NTRS)

Raven, P. B.

1999-01-01

Astronauts are often required to work (exercise) at moderate to high intensities for extended periods while performing extra-vehicular activities (EVA). Although the physiologic responses associated with prolonged exercise have been documented, the mechanisms involved in blood pressure regulation under these conditions have not yet been fully elucidated. An understanding of this issue is pertinent to the ability of humans to perform work in microgravity and complies with the emphasis of NASA's Space Physiology and Countermeasures Program. Prolonged exercise at a constant workload is know to result in a progressive decrease in mean arterial pressure (MAP) concomitant with a decrease in stroke volume and a compensatory increase in heart rate. The continuous decrease in MAP during the exercise, which is related to the thermoregulatory redistribution of circulating blood volume to the cutaneous circulation, raises the question as to whether there is a loss of baroreflex regulation of arterial blood pressure. We propose that with prolongation of the exercise to 60 minutes, progressive increases on central command reflect a progressive upward resetting of the carotid baroreflex (CBR) such that the operating point of the CBR is shifted to a pressure below the threshold of the reflex rendering it ineffectual in correcting the downward drift in MAP. In order to test this hypothesis, experiments have been designed to uncouple the global hemodynamic response to prolonged exercise from the central command mediated response via: (1) continuous maintenance of cardiac filling volume by intravenous infusion of a dextran solution; and (2) whole body surface cooling to counteract thermoregulatory cutaneous vasodialation. As the type of work (exercise) performed by astronauts is inherently arm and upper body dependent, we will also examine the physiologic responses to prolonged leg cycling and arm ergometry exercise in the supine positions with and without level lower body negative pressure (-10 torr) to mimic spaceflight- related decreases in cardiac filling volumes.

Blood Pressure Response to Exercise and Cardiovascular Disease.

PubMed

Schultz, Martin G; La Gerche, Andre; Sharman, James E

2017-10-18

This review aimed to provide a clinical update on exercise blood pressure (BP) and its relationship to cardiovascular disease (CVD), outlining key determinants of abnormal exercise BP responses. We also highlight current evidence gaps that need addressing in order to optimise the relevance of exercise BP as clinical CVD risk factor. Abnormal exercise BP manifests as either exercise hypotension (low BP response) or as exaggerated exercise BP (high BP response). Exercise hypotension is an established sign of existing and likely severe CVD, but exaggerated exercise BP also carries elevated CVD risk due to its association with sub-clinical hypertension. Although exaggerated exercise BP is related to heightened CVD risk at any exercise intensity, recent data suggest that the BP response to submaximal intensity exercise holds greater prognostic and clinical significance than BP achieved at peak/maximal intensity exercise. Cardiorespiratory fitness is a strong modifier of the exercise BP response, and should be taken into consideration when assessing the association with CVD. Both exercise hypotension and exaggerated exercise BP serve as markers that should prompt evaluation for potential underlying CVD. However, the clinical utility of these markers is currently inhibited by the lack of consensus informing the definitions and thresholds for abnormalities in exercise BP.

A randomized controlled crossover trial of the effect of ginseng consumption on the immune response to moderate exercise in healthy sedentary men.

PubMed

Biondo, Patricia D; Robbins, Sarah J; Walsh, Jennifer D; McCargar, Linda J; Harber, Vicki J; Field, Catherine J

2008-10-01

Ginseng is a popular herbal remedy that is reputed to increase resistance to stress and improve immune function. Regular exercise results in acute physiologic stress that affects the immune response. This study was conducted to investigate the effects of daily consumption of a standardized ginsenoside-containing North American ginseng (Panax quinquefolius) extract on immune function before, during, and after a moderate-exercise protocol in healthy sedentary men. Ten healthy males were randomized to receive either ginseng (1125 mg.d-1) or placebo for 35 days. After a 3 month washout period, subjects received the opposite treatment for another 35 days. An exercise test and blood collection were performed at the end of each treatment period. Immune parameters and blood hormone levels were measured before, during, and after the exercise stress protocol. Ginseng treatment reduced the peripheral blood concentration of CD8+ T cells and increased mitogen-stimulated T cell production of interleukin-2 ex vivo. Ginseng had no effect on total white blood cell counts; on concentrations of neutrophils, monocytes, or lymphocytes (CD3+, CD4+, CD16+, CD20+); on lymphocyte proliferation; or on neutrophil oxidative burst. Ginseng did not significantly affect exercise-induced changes in plasma concentrations of lactate, insulin, cortisol, or growth hormone. The consumption of ginseng for 5 weeks had a limited effect on the immune response to an acute exercise protocol.

Blood and muscle metabolic responses to draught work of varying intensity and duration in horses.

PubMed

Gottlieb, M; Essén-Gustavsson, B; Skoglund-Wallberg, H

1989-07-01

Three standardbred trotters performed treadmill exercise at a velocity of 2 m s-1 with a draught load of both 34 kiloponds (kp) (test 1) and 80 kp (test 2), and also at 7 m s-1 with 34 kp (test 3). The heart rate increased to average values of 111 (+/- 5), 157 (+/- 10) and 197 (+/- 7) beats min-1 in tests 1, 2, and 3, respectively. Plasma free fatty acids increased only during tests 1 and 2. Blood lactate and muscle glucose-6-phosphate and lactate concentrations were low after tests 1 and 2, but high after test 3, where also muscle glycogen utilisation was greatest. Muscle creatine phosphate and adenosine triphosphate concentrations decreased after test 3 only. The study indicates that oxidative metabolism is most important for energy supply in muscles when exercise is performed with draught loads of both 34 and 80 kp at a low velocity. Glycogenolysis with lactate accumulation and phosphagen breakdown becomes much more important when, with a draught load of 34 kp, the velocity of exercise increases.

Increased cardiac output elicits higher V̇O2max in response to self-paced exercise.

PubMed

Astorino, Todd Anthony; McMillan, David William; Edmunds, Ross Montgomery; Sanchez, Eduardo

2015-03-01

Recently, a self-paced protocol demonstrated higher maximal oxygen uptake versus the traditional ramp protocol. The primary aim of the current study was to further explore potential differences in maximal oxygen uptake between the ramp and self-paced protocols using simultaneous measurement of cardiac output. Active men and women of various fitness levels (N = 30, mean age = 26.0 ± 5.0 years) completed 3 graded exercise tests separated by a minimum of 48 h. Participants initially completed progressive ramp exercise to exhaustion to determine maximal oxygen uptake followed by a verification test to confirm maximal oxygen uptake attainment. Over the next 2 sessions, they performed a self-paced and an additional ramp protocol. During exercise, gas exchange data were obtained using indirect calorimetry, and thoracic impedance was utilized to estimate hemodynamic function (stroke volume and cardiac output). One-way ANOVA with repeated measures was used to determine differences in maximal oxygen uptake and cardiac output between ramp and self-paced testing. Results demonstrated lower (p < 0.001) maximal oxygen uptake via the ramp (47.2 ± 10.2 mL·kg(-1)·min(-1)) versus the self-paced (50.2 ± 9.6 mL·kg(-1)·min(-1)) protocol, with no interaction (p = 0.06) seen for fitness level. Maximal heart rate and cardiac output (p = 0.02) were higher in the self-paced protocol versus ramp exercise. In conclusion, data show that the traditional ramp protocol may underestimate maximal oxygen uptake compared with a newly developed self-paced protocol, with a greater cardiac output potentially responsible for this outcome.

Cardiac autonomic impairment and chronotropic incompetence in fibromyalgia.

PubMed

da Cunha Ribeiro, Roberta Potenza; Roschel, Hamilton; Artioli, Guilherme Gianini; Dassouki, Thalita; Perandini, Luiz Augusto; Calich, Ana Luisa; de Sá Pinto, Ana Lúcia; Lima, Fernanda Rodrigues; Bonfá, Eloísa; Gualano, Bruno

2011-01-01

We aimed to gather knowledge on the cardiac autonomic modulation in patients with fibromyalgia (FM) in response to exercise and to investigate whether this population suffers from chronotropic incompetence (CI). Fourteen women with FM (age: 46 ± 3 years; body mass index (BMI): 26.6 ± 1.4 kg/m2) and 14 gender-, BMI- (25.4 ± 1.3 kg/m2), and age-matched (age: 41 ± 4 years) healthy individuals (CTRL) took part in this cross-sectional study. A treadmill cardiorespiratory test was performed and heart-rate (HR) response during exercise was evaluated by the chronotropic reserve. HR recovery (deltaHRR) was defined as the difference between HR at peak exercise and at both first (deltaHRR1) and second (deltaHRR2) minutes after the exercise test. FM patients presented lower maximal oxygen consumption (VO2 max) when compared with healthy subjects (22 ± 1 versus CTRL: 32 ± 2 mL/kg/minute, respectively; P < 0.001). Additionally, FM patients presented lower chronotropic reserve (72.5 ± 5 versus CTRL: 106.1 ± 6, P < 0.001), deltaHRR1 (24.5 ± 3 versus CTRL: 32.6 ± 2, P = 0.059) and deltaHRR2 (34.3 ± 4 versus CTRL: 50.8 ± 3, P = 0.002) than their healthy peers. The prevalence of CI was 57.1% among patients with FM. Patients with FM who undertook a graded exercise test may present CI and delayed HR recovery, both being indicative of cardiac autonomic impairment and higher risk of cardiovascular events and mortality.

Evaluation of Dogs with Border Collie Collapse, Including Response to Two Standardized Strenuous Exercise Protocols.

PubMed

Taylor, Susan; Shmon, Cindy; Su, Lillian; Epp, Tasha; Minor, Katie; Mickelson, James; Patterson, Edward; Shelton, G Diane

2016-01-01

Clinical and metabolic variables were evaluated in 13 dogs with border collie collapse (BCC) before, during, and following completion of standardized strenuous exercise protocols. Six dogs participated in a ball-retrieving protocol, and seven dogs participated in a sheep-herding protocol. Findings were compared with 16 normal border collies participating in the same exercise protocols (11 retrieving, five herding). Twelve dogs with BCC developed abnormal mentation and/or an abnormal gait during evaluation. All dogs had post-exercise elevations in rectal temperature, pulse rate, arterial blood pH, PaO2, and lactate, and decreased PaCO2 and bicarbonate, as expected with strenuous exercise, but there were no significant differences between BCC dogs and normal dogs. Electrocardiography demonstrated sinus tachycardia in all dogs following exercise. Needle electromyography was normal, and evaluation of muscle biopsy cryosections using a standard panel of histochemical stains and reactions did not reveal a reason for collapse in 10 dogs with BCC in which these tests were performed. Genetic testing excluded the dynamin-1 related exercise-induced collapse mutation and the V547A malignant hyperthermia mutation as the cause of BCC. Common reasons for exercise intolerance were eliminated. Although a genetic basis is suspected, the cause of collapse in BCC was not determined.

Exercise-mediated vasodilation in human obesity and metabolic syndrome: effect of acute ascorbic acid infusion.

PubMed

Limberg, Jacqueline K; Kellawan, J Mikhail; Harrell, John W; Johansson, Rebecca E; Eldridge, Marlowe W; Proctor, Lester T; Sebranek, Joshua J; Schrage, William G

2014-09-15

We tested the hypothesis that infusion of ascorbic acid (AA), a potent antioxidant, would alter vasodilator responses to exercise in human obesity and metabolic syndrome (MetSyn). Forearm blood flow (FBF, Doppler ultrasound) was measured in lean, obese, and MetSyn adults (n = 39, 32 ± 2 yr). A brachial artery catheter was inserted for blood pressure monitoring and local infusion of AA. FBF was measured during dynamic handgrip exercise (15% maximal effort) with and without AA infusion. To account for group differences in blood pressure and forearm size, and to assess vasodilation, forearm vascular conductance (FVC = FBF/mean arterial blood pressure/lean forearm mass) was calculated. We examined the time to achieve steady-state FVC (mean response time, MRT) and the rise in FVC from rest to steady-state exercise (Δ, exercise - rest) before and during acute AA infusion. The MRT (P = 0.26) and steady-state vasodilator responses to exercise (ΔFVC, P = 0.31) were not different between groups. Intra-arterial infusion of AA resulted in a significant increase in plasma total antioxidant capacity (174 ± 37%). AA infusion did not alter MRT or steady-state FVC in any group (P = 0.90 and P = 0.85, respectively). Interestingly, higher levels of C-reactive protein predicted longer MRT (r = 0.52, P < 0.01) and a greater reduction in MRT with AA infusion (r = -0.43, P = 0.02). We concluded that AA infusion during moderate-intensity, rhythmic forearm exercise does not alter the time course or magnitude of exercise-mediated vasodilation in groups of young lean, obese, or MetSyn adults. However, systemic inflammation may limit the MRT to exercise, which can be improved with AA. Copyright © 2014 the American Physiological Society.

Exercise-mediated vasodilation in human obesity and metabolic syndrome: effect of acute ascorbic acid infusion

PubMed Central

Limberg, Jacqueline K.; Kellawan, J. Mikhail; Harrell, John W.; Johansson, Rebecca E.; Eldridge, Marlowe W.; Proctor, Lester T.; Sebranek, Joshua J.

2014-01-01

We tested the hypothesis that infusion of ascorbic acid (AA), a potent antioxidant, would alter vasodilator responses to exercise in human obesity and metabolic syndrome (MetSyn). Forearm blood flow (FBF, Doppler ultrasound) was measured in lean, obese, and MetSyn adults (n = 39, 32 ± 2 yr). A brachial artery catheter was inserted for blood pressure monitoring and local infusion of AA. FBF was measured during dynamic handgrip exercise (15% maximal effort) with and without AA infusion. To account for group differences in blood pressure and forearm size, and to assess vasodilation, forearm vascular conductance (FVC = FBF/mean arterial blood pressure/lean forearm mass) was calculated. We examined the time to achieve steady-state FVC (mean response time, MRT) and the rise in FVC from rest to steady-state exercise (Δ, exercise − rest) before and during acute AA infusion. The MRT (P = 0.26) and steady-state vasodilator responses to exercise (ΔFVC, P = 0.31) were not different between groups. Intra-arterial infusion of AA resulted in a significant increase in plasma total antioxidant capacity (174 ± 37%). AA infusion did not alter MRT or steady-state FVC in any group (P = 0.90 and P = 0.85, respectively). Interestingly, higher levels of C-reactive protein predicted longer MRT (r = 0.52, P < 0.01) and a greater reduction in MRT with AA infusion (r = −0.43, P = 0.02). We concluded that AA infusion during moderate-intensity, rhythmic forearm exercise does not alter the time course or magnitude of exercise-mediated vasodilation in groups of young lean, obese, or MetSyn adults. However, systemic inflammation may limit the MRT to exercise, which can be improved with AA. PMID:25038148

Cerebral Blood Flow Responses to Aquatic Treadmill Exercise.

PubMed

Parfitt, Rhodri; Hensman, Marianne Y; Lucas, Samuel J E

2017-07-01

Aquatic treadmills are used as a rehabilitation method for conditions such as spinal cord injury, osteoarthritis, and stroke, and can facilitate an earlier return to exercise training for athletes. However, their effect on cerebral blood flow (CBF) responses has not been examined. We tested the hypothesis that aquatic treadmill exercise would augment CBF and lower HR compared with land-based treadmill exercise. Eleven participants completed incremental exercise (crossover design) starting from walking pace (4 km·h, immersed to iliac crest [aquatic], 6 km·h [land]) and increasing 1 km·h every 2 min up to 10 km·h for aquatic (maximum belt speed) or 12 km·h for land. After this, participants completed two 2-min bouts of exercise immersed to midthigh and midchest at constant submaximal speed (aquatic), or were ramped to exhaustion (land; increased gradient 2° every min). Middle cerebral artery blood flow velocity (MCAv) and HR were measured throughout, and the initial 10 min of each protocol and responses at each immersion level were compared. Compared with land-based treadmill, MCAvmean increased more from baseline for aquatic exercise (21% vs 12%, P < 0.001), while being associated with lower overall HR (pooled difference, 11 bpm; P < 0.001). MCAvmean increased similarly during aquatic walking compared with land-based moderate intensity running (~10 cm·s, P = 0.56). Greater water immersion lowered HR (139 vs 178 bpm for midchest vs midthigh), whereas MCAvmean remained constant (P = 0.37). Findings illustrate the potential for aquatic treadmill exercise to enhance exercise-induced elevations in CBF and thus optimize shear stress-mediated adaptation of the cerebrovasculature.

Effect of strenuous exercise and ex vivo TLR3 and TLR4 stimulation on inflammatory gene expression in equine pulmonary leukocytes.

PubMed

Mignot, Clémence C; Pirottin, Dimitri; Farnir, Frédéric; de Moffarts, Brieuc; Molitor, Céline; Lekeux, Pierre; Art, Tatiana

2012-06-30

The effects of strenuous exercise and ex vivo stimulation of TLR3 and TLR4 pathways on the expression of six inflammatory genes in equine pulmonary leukocytes were investigated. The genes tested were interferon-beta (IFN-β), interleukin-1-beta (IL-1β), interleukin-6 (IL-6), interferon gamma-induced protein 10 (IP-10), chemokine (c-c motif) ligand 5 (RANTES) and tumor necrosis factor-alpha (TNF-α). We hypothesized that strenuous exercise would modulate basal gene expression on one hand and modulate the response to bacterial lipopolysaccharide (LPS) and to polyinosinic:polycytidylic acid (Poly IC) on the other hand. Eight young Thoroughbred mares were selected for the experiment. Bronchoalveolar lavages were performed on horses 48 h before and 24h after the completion of treadmill exercise until fatigue. Differential counts were performed on the bronchoalveolar lavage cells. Real-time PCR was used to quantify cytokine expression in pulmonary leukocytes. Target gene expression was normalized to the expression of three housekeeping genes (HKG). There were no significant differences in the mRNA expression of the six cytokines between pre-exercise and post-exercise cells. LPS and Poly IC induced respectively significant increases of TNF-α, IFN-β, IL-6, IL-1β, and TNF-α, IFN-β, IP-10 and RANTES, both before and after exercise. However, exercise induced a significant decrease of the genes response to LPS and Poly IC. These findings may suggest that strenuous treadmill exercise exerts a deleterious effect on part of the pulmonary immune response in horses 24h following an intense physical activity. Copyright © 2012 Elsevier B.V. All rights reserved.

Maximal strength and cortisol responses to psyching-up during the squat exercise.

PubMed

McGuigan, Michael R; Ghiagiarelli, Jamie; Tod, David

2005-07-01

We studied the effect of psyching-up on one-repetition maximum (1-RM) performance and salivary cortisol responses during the squat exercise. Ten men (age 21.6+/-1.4 years; mean+/-s) and ten women (age 22.4+/-2.8 years) with weight training experience of 4.5+/-2.0 years participated in this study. One-repetition maximum squats were performed on a Smith machine during each of two different intervention conditions that were counterbalanced and consisted of a free choice psych-up and a cognitive distraction. Saliva samples were obtained at the beginning of each test session and immediately after the final 1-RM attempt. No significant difference in 1-RM was identified between psyching-up (104+/-50 kg) and cognitive distraction (106+/-52 kg). Performing a 1-RM in the squat exercise significantly increased salivary cortisol concentrations during both conditions (P<0.05). There was no significant difference in salivary cortisol responses between conditions. These results suggest that psyching-up does not increase 1-RM performance during the squat exercise in strength-trained individuals.

Can previously sedentary females use the feeling scale to regulate exercise intensity in a gym environment? an observational study.

PubMed

Hamlyn-Williams, Charlotte C; Tempest, Gavin; Coombs, Sarah; Parfitt, Gaynor

2015-01-01

Recent research suggests that the Feeling Scale (FS) can be used as a method of exercise intensity regulation to maintain a positive affective response during exercise. However, research to date has been carried out in laboratories and is not representative of natural exercise environments. The purpose of this study was to evaluate whether sedentary women can self-regulate their exercise intensity using the FS to experience positive affective responses in a gym environment using their own choice of exercise mode; cycling or treadmill. Fourteen females (24.9 years ± 5.2; height 166.7 ± 5.7 cm; mass 66.3 ± 13.4 kg; BMI 24.1 ± 5.5)) completed a submaximal exercise test and each individual's ventilatory threshold ([Formula: see text]) was identified. Following this, three 20 min gym-based exercise trials, either on a bike or treadmill were performed at an intensity that was self-selected and perceived to correspond to the FS value of +3 (good). Oxygen uptake, heart rate (HR) and ratings of perceived exertion (RPE) were measured during exercise at the participants chosen intensity. Results indicated that on average participants worked close to their [Formula: see text] and increased their exercise intensity during the 20-min session. Participants worked physiologically harder during cycling exercise. Consistency of oxygen uptake, HR and RPE across the exercise trials was high. The data indicate that previously sedentary women can use the FS in an ecological setting to regulate their exercise intensity and that regulating intensity to feel 'good' should lead to individuals exercising at an intensity that would result in cardiovascular gains if maintained.

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

NASA Technical Reports Server (NTRS)

Bennett, C. H.

1981-01-01

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

Essential Hypertension: Cardiovascular Response to Breath Hold Combined with Exercise.

PubMed

Hoffmann, U; Urban, P; Koschate, J; Drescher, U; Pfister, R; Michels, G

2015-07-01

Essential hypertension (EH) is a widespread disease and might be prevalent in apnea divers and master athletes. Little is known about the influence of EH and the antihypertensive drugs (AHD) on cardiovascular reactions to combined breath hold (BH) and exercise. In this pilot study, healthy divers (HCON) were compared with treated hypertensive divers with regard to heart rate (HR) and mean blood-pressure (MAP) responses to BH, exercise and the combination of both. Ten subjects with EH and ten healthy divers were tested. 3 different 20 s stimuli were applied: BH combined with 30 W or 150 W and 150 W without BH. The time-charts during the stress intervals and during recovery were compared. Subjects treated with an angiotensin-converting enzyme (ACE) inhibitor showed higher changes for MAP values if breath hold was performed. HR responses were obviously changed if a β-blocker was part of the medication. One subject showed extreme MAP responses to all stimuli and conspicuous HR if BH was involved. The modulation of HR-/MAP-response in EH subjects depends on the mechanisms of antihypertensive agents. The combination of an ACE inhibitor and a β-blocker may give the best protection. It is recommended to include short apnea tests in the fitness-to-dive examination to individually predict potential endangerment. © Georg Thieme Verlag KG Stuttgart · New York.

Cardiac investigation in patients with diabetes.

PubMed

Tardif, Jean-Claude

2006-02-01

Most patients with type 2 diabetes die from heart disease. Screening for the presence of myocardial ischemia is of clinical importance in the management of this population. The pain response to ischemia can be either absent or blunted in diabetes, resulting in the absence of symptoms or an atypical presentation. Exercise electrocardiogram (ECG) should be the initial test in men who are able to exercise and have a normal resting ECG. Stress cardiac imaging should be the initial test in diabetic men with an abnormal resting ECG or who are not able to exercise. More widespread use of cardiac imaging is probably justified in diabetic women and patients with suspected coronary artery disease. Official guidelines for appropriate and cost-effective cardiac investigation should help physicians manage diabetic patients.

Comparing the effects of two in-flight aerobic exercise protocols on standing heart rates and VO(2peak) before and after space flight

NASA Technical Reports Server (NTRS)

Siconolfi, S. F.; Charles, J. B.; Moore, A. D. Jr; Barrows, L. H.

1994-01-01

The effects of regular aerobic exercise on orthostatic tolerance have been the subject of a long-standing controversy that will influence the use of exercise during space flight. To examine these effects, astronauts performed continuous (CE) aerobic exercise (n = 8), interval (IE) aerobic exercise (n = 4), or no (NE) exercise (n = 5) during flights of 7 to 11 days. Heart rate (HR) responses to an orthostatic challenge (stand test) were measured 10 days before flight and on landing day. VO(2peak) (graded treadmill exercise) was measured 7 to 21 days before and 2 days after flight. No significant differences across the groups were observed in standing HRs before or after flight. However, the within-group mean HRs significantly increased in the NE (71-89 beats/min) and CE (60-85 beats/min) groups after space flight. The HRs for the IE group did not significantly increase (75-86 beats/min) after space flight. VO(2peak) decreased (P < .05) in the NE (-9.5%) group, but did not change in the CE (-2.4%) and IE (1%) groups. The relationship (r = 0.237) between the delta HR and delta VO(2peak) was not significant. These preliminary results indicate that: (1) continuous exercise does not affect the orthostatic HR response after space flight; (2) interval exercise may minimize an increase in the postflight orthostatic HR; and (3) both exercise protocols can maintain VO(2peak).

Sensitizing Undergraduates to Potential Inaccuracies in Projective Test Interpretation.

ERIC Educational Resources Information Center

Barret, Robert L.; Wachowiak, Dale G.

This paper describes a methodology developed to provide undergraduate students with direct experience in the process of impressionistic test interpretation. In the experiential exercise, students were shown Thematic Apperception Test cards and then read the responses given by an anonymous client. A discussion of the process by which the students…

Change in convergence and accommodation after two weeks of eye exercises in typical young adults.

PubMed

Horwood, Anna M; Toor, Sonia S; Riddell, Patricia M

2014-04-01

Although eye exercises appear to help heterophoria, convergence insufficiency, and intermittent strabismus, results can be confounded by placebo, practice, and encouragement effects. This study assessed objective changes in vergence and accommodation responses in naive young adults after a 2-week period of eye exercises under controlled conditions to determine the extent to which treatment effects occur over other factors. Asymptomatic young adults were randomly assigned to one of two no-treatment (control) groups or to one of six eye exercise groups: accommodation, vergence, both, convergence in excess of accommodation, accommodation in excess of convergence, and placebo. Subjects were tested and retested under identical conditions, except for the second control group, who were additionally encouraged. Objective accommodation and vergence were assessed to a range of targets moving in depth containing combinations of blur, disparity, and proximity/looming cues. A total of 156 subjects were included. Response gain improved more for less naturalistic targets where more improvement was possible. Convergence exercises improved vergence for near across all targets (P = 0.035). Mean accommodation changed similarly but nonsignificantly. No other treatment group differed significantly from the nonencouraged control group, whereas encouraging effort produced significantly increased vergence (P = 0.004) and accommodation (P = 0.005) gains in the second control group. True treatment effects were small, significantly better only after vergence exercises to a nonaccommodative target, and rarely related to the response they were designed to improve. Exercising accommodation without convergence made no difference to accommodation to cues containing detail. Additional effort improved objective responses the most. Copyright © 2014 American Association for Pediatric Ophthalmology and Strabismus. Published by Mosby, Inc. All rights reserved.

Effects of a long acting somatostatin analog on pituitary, adrenal, and testicular function during rest and acute exercise: unexpected stimulation of testosterone secretion.

PubMed

Vasankari, T; Kujala, U; Taimela, S; Törmä, A; Irjala, K; Huhtaniemi, I

1995-11-01

The purpose of this study was to delineate the possible endocrine effects of exercise-induced GH secretion. Twelve healthy adult males were studied during short (20 min) and subsequent prolonged (2 h) physical exercise and recovery period (2 h), both after injection of a long acting somatostatin analog [Sandostatin (ST); 0.1 or 0.05 mg, sc] and after a control saline injection. Additional subjects were studied during rest with similar injections of ST (0.1 mg) and saline (n = 7) or using a lower ST dose (0.01 mg; n = 6). Several venous blood samples were taken during the trials and analyzed for selected hormones, monitoring pituitary, testicular, and adrenal functions. ST injection blocked the serum GH response to short term maximal bicycle ergometer exercise, but not to the following prolonged bicycle exercise. No relationship of the exercise-associated GH increase to the concomitant endocrine responses of the adrenals and testes was observed. Unexpectedly, the higher ST doses (0.1 and 0.05 mg) increased the mean levels of serum testosterone by 18-25% in both exercise (P = 0.0017) and rest trials (P < 0.0001), respectively. ST did not affect the levels of LH, FSH, or cortisol. ST slightly increased serum sex hormone-binding globulin (3%; P = 0.021) and albumin (4%; P = 0.017) concentrations, but not that of free testosterone. Because the testosterone response to somatostatin was fast and without a simultaneous increase in LH, it was consistent with a direct testicular response. The explanation for this novel ST effect remains obscure, but it may be due to modulation of some paracrine mechanisms inhibiting testicular steroidogenesis.

Exergaming boxing versus heavy-bag boxing: are these equipotent for individuals with spinal cord injury?

PubMed

Mat Rosly, Maziah; Mat Rosly, Hadi; Hasnan, Nazirah; Davis, Glen M; Husain, Ruby

2017-08-01

Current strategies for increased physical activity and exercise in individuals with spinal cord injury (SCI) face many challenges with regards to maintaining their continuity of participation. Barriers cited often include problems with accessing facilities, mundane, monotonous or boring exercises and expensive equipment that is often not adapted for wheelchair users. To compare the physiological responses and user preferences between conventional heavy-bag boxing against a novel form of video game boxing, known as exergaming boxing. Cross-sectional study. Exercise laboratory setting in a university medical center. Seventeen participants with SCI were recruited, of which sixteen were male and only one female. Their mean age was 35.6±10.2 years. All of them performed a 15-minute physical exercise session of exergaming and heavy-bag boxing in a sitting position. The study assessed physiological responses in terms of oxygen consumption, metabolic equivalent (MET) and energy expenditure between exergaming and heavy-bag boxing derived from open-circuit spirometry. Participants also rated their perceived exertion using Borg's category-ratio ratings of perceived exertion. Both exergaming (MET: 4.3±1.0) and heavy-bag boxing (MET: 4.4±1.0) achieved moderate exercise intensities in these participants with SCI. Paired t-test revealed no significant differences (P>0.05, Cohen's d: 0.02-0.49) in the physiological or perceived exertional responses between the two modalities of boxing. Post session user survey reported all the participants found exergaming boxing more enjoyable. Exergaming boxing, was able to produce equipotent physiological responses as conventional heavy-bag boxing. The intensity of both exercise modalities achieved recommended intensities for health and fitness benefits. Exergaming boxing have the potential to provide an enjoyable, self-competitive environment for moderate-vigorous exercise even at the comfort of their homes.

Sex differences in creatine kinase after acute heavy resistance exercise on circulating granulocyte estradiol receptors.

PubMed

Wolf, Megan R; Fragala, Maren S; Volek, Jeff S; Denegar, Craig R; Anderson, Jeffrey M; Comstock, Brett A; Dunn-Lewis, Courtenay; Hooper, David R; Szivak, Tunde K; Luk, Hui-Ying; Maresh, Carl M; Häkkinen, Keijo; Kraemer, William J

2012-09-01

Previous research has shown reduced tissue disruption and inflammatory responses in women as compared to men following acute strenuous exercise. While the mechanism of this action is not known, estrogen may reduce the inflammatory response through its interaction with granulocytes. The purpose of this study was to determine if estrogen receptor β expression on granulocytes is related to sex differences in tissue disruption in response to an acute heavy resistance exercise protocol. Seven healthy, resistance-trained, eumenorrheic women (23 ± 3 years, 169 ± 9.1 cm, 66.4 ± 10.5 kg) and 8 healthy, resistance-trained men (25 ± 5 years, 178 ± 6.7 cm, 82.3 ± 9.33 kg) volunteered to participate in the study. Subjects performed an acute resistance exercise test consisting of six sets of five squats at 90% of the subject's one repetition maximum. Blood samples were obtained pre-, mid-, post-, and 1-, 6-, and 24-h postexercise. Blood samples were analyzed for 17-β-estradiol by ELISA, creatine kinase by colorimetric enzyme immunoassay, and estradiol receptors on circulating granulocytes through flow cytometry. Men had higher CK concentrations than women at baseline/control. Men had significantly higher CK concentrations at 24-h postexercise than women. No significant changes in estradiol β receptors were expressed on granulocytes after exercise or between sexes. While sex differences occur in CK activity in response to strenuous eccentric exercise, they may not be related to estradiol receptor β expression on granulocytes. Thus, although there are sex differences in CK expression following acute resistance exercise, the differences may not be attributable to estrogen receptor β expression on granulocytes.

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.

Sex impacts the flow-mediated dilation response to acute aerobic exercise in older adults.

PubMed

Yoo, Jeung-Ki; Pinto, Michelle M; Kim, Han-Kyul; Hwang, Chueh-Lung; Lim, Jisok; Handberg, Eileen M; Christou, Demetra D

2017-05-01

There is growing evidence of sex differences in the chronic effect of aerobic exercise on endothelial function (flow-mediated dilation; FMD) in older adults, but whether there are sex differences also in the acute effect of aerobic exercise on FMD in older adults is unknown. The purpose of this study was to test the hypothesis that sex modulates the FMD response to acute aerobic exercise in older adults. Thirteen older men and fifteen postmenopausal women (67±1 vs. 65±2years, means±SE, P=0.6), non-smokers, free of major clinical disease, participated in this randomized crossover study. Brachial artery FMD was measured: 1) prior to exercise; 2) 20min after a single bout of high-intensity interval training (HIIT; 40min; 4×4 intervals 90% peak heart rate (HRpeak)), moderate-intensity continuous training (MICT; 47min 70% HRpeak) and low-intensity continuous training (LICT; 47min 50% HRpeak) on treadmill; and 3) following 60-min recovery from exercise. In older men, FMD was attenuated by 45% following HIIT (5.95±0.85 vs. 3.27±0.52%, P=0.003) and by 37% following MICT (5.97±0.87 vs. 3.73±0.47%, P=0.03; P=0.9 for FMD response to HIIT vs. MICT) and was normalized following 60-min recovery (P=0.99). In postmenopausal women, FMD did not significantly change in response to HIIT (4.93±0.55 vs. 6.31±0.57%, P=0.14) and MICT (5.32±0.62 vs. 5.60±0.68%, P=0.99). In response to LICT, FMD did not change in postmenopausal women nor older men (5.21±0.64 vs. 6.02±0.73%, P=0.7 and 5.70±0.80 vs. 5.55±0.67%, P=0.99). In conclusion, sex and exercise intensity influence the FMD response to acute aerobic exercise in older adults. Copyright © 2017 Elsevier Inc. All rights reserved.

Reliability, agreement, and responsiveness of a 6-minute walk/run test in patients with heart disease.

PubMed

Berghmans, Danielle D; Lenssen, Antoine F; Bastiaenen, Carolien H; Ilhan, Mustafa; Lencer, Nicole H; Roox, George M

2013-02-01

The 6-minute walk test (6 MWT) is widely used to assess exercise tolerance in cardiac rehabilitation (CR). However, previous research shows it to be insufficiently responsive, especially for patients with a relatively high maximal exercise tolerance at baseline. We therefore designed a 6-minute walk/run test (6 MWRT), which has the same duration as the 6 MWT but allows running. The objective of this study was to determine the test-retest reproducibility and responsiveness of this 6 MWRT. Responsiveness was investigated in a prospective cohort study among a group of patients entering CR at Maastricht University Medical Center, with a cross-sectional part to assess the test-retest reproducibility. Test-retest reproducibility (reliability and agreement) was investigated using the intraclass correlation (ICC) and a Bland-Altman plot of two measurements implemented in the first week of rehabilitation. Responsiveness of the 6 MWT and the 6 MWRT was calculated using the standard response mean (SRM) over a 6-week period. The first reproducibility analysis included 34 patients, the second 22 patients. The ICCs were 0.935 and 0.906, respectively, with limits of agreement of ± 79 and ± 61 m. The responsiveness analysis included 27 patients. The SRM values were 0.83 for the 6 MWT and 0.71 for the 6 MWRT. Although the 6 MWRT is a reproducible test in CR, its responsiveness is not superior to that of the 6 MWT. We therefore prefer the conventional 6 MWT as an evaluative measurement in CR and advise against using the 6 MWRT as (evaluative) measurement in CR for this purpose.

Exercise training for intermittent claudication.

PubMed

McDermott, Mary M

2017-11-01

The objective of this study was to provide an overview of evidence regarding exercise therapies for patients with lower extremity peripheral artery disease (PAD). This manuscript summarizes the content of a lecture delivered as part of the 2016 Crawford Critical Issues Symposium. Multiple randomized clinical trials demonstrate that supervised treadmill exercise significantly improves treadmill walking performance in people with PAD and intermittent claudication symptoms. A meta-analysis of 25 randomized trials demonstrated a 180-meter increase in treadmill walking distance in response to supervised exercise interventions compared with a nonexercising control group. Supervised treadmill exercise has been inaccessible to many patients with PAD because of lack of medical insurance coverage. However, in 2017, the Centers for Medicare and Medicaid Services issued a decision memorandum to support health insurance coverage of 12 weeks of supervised treadmill exercise for patients with walking impairment due to PAD. Recent evidence also supports home-based walking exercise to improve walking performance in people with PAD. Effective home-exercise programs incorporate behavioral change interventions such as a remote coach, goal setting, and self-monitoring. Supervised treadmill exercise programs preferentially improve treadmill walking performance, whereas home-based walking exercise programs preferentially improve corridor walking, such as the 6-minute walk test. Clinical trial evidence also supports arm or leg ergometry exercise to improve walking endurance in people with PAD. Treadmill walking exercise appears superior to resistance training alone for improving walking endurance. Supervised treadmill exercise significantly improves treadmill walking performance in people with PAD by approximately 180 meters compared with no exercise. Recent evidence suggests that home-based exercise is also effective and preferentially improves over-ground walking performance, such as the 6-minute walk test. Copyright © 2017 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

The Online Big Blue Test for Promoting Exercise: Health, Self-Efficacy, and Social Support.

PubMed

Gómez-Zúñiga, Beni; Pousada, Modesta; Hernandez, Manny M; Colberg, Sheri; Gabarrón, Elia; Armayones, Manuel

2015-10-01

Recent articles have documented the influence of self-efficacy and social support on exercising. Simultaneously, insulin use is also related to the perception of self-efficacy and social support in patients with diabetes. We combine these two ideas through the Big Blue Test experience in a social networking site and propose to analyze whether a change in blood sugar levels after completion of the Big Blue Test and insulin use are related to the perception of self-efficacy and social support in patients with diabetes. To undergo the Big Blue Test, 3,926 participants voluntarily joined the Diabetes Hands Foundation. Responses were analyzed using descriptive analysis. The participants who reduced their blood glucose after exercise the least were those with lower self-efficacy and also with lower perceived social support. There seems to have been no relationship between changes in blood sugar level and the explicit intention of doing exercise in the future. Insulin-dependent participants demonstrated a lower perception of self-efficacy and social support than non-insulin-dependent participants. Change in blood glucose level or being insulin-dependent or not do not explain completely a health behavior such as exercise. Hence, self-efficacy and social support have an impact on behavioral change such as exercise to become a habit in people with diabetes, and this experience through a social networking site is an important tool for this behavioral change. For exercise to become a habit in people with diabetes, it is necessary to consider not only the crucial physiological variables, but also those psychological variables that clearly have an impact on behavioral change.

Inbred Strain-Specific Effects of Exercise in Wild Type and Biglycan Deficient Mice

PubMed Central

Wallace, Joseph M.; Golcuk, Kurtulus; Morris, Michael D.; Kohn, David H.

2010-01-01

Biglycan (bgn)-deficient mice (KO) have defective osteoblasts which lead to changes in the amount and quality of bone. Altered tissue strength in C57BL6/129 (B6;129) KO mice, a property which is independent of tissue quantity, suggests that deficiencies in tissue quality are responsible. However, the response to bgn-deficiency is inbred strain-specific. Mechanical loading influences bone matrix quality in addition to any increase in bone mass or change in bone formation activity. Since many diseases influence the mechanical integrity of bone through altered tissue quality, loading may be a way to prevent and treat extracellular matrix deficiencies. C3H/He (C3H) mice consistently have a less vigorous response to mechanical loading vs. other inbred strains. It was therefore hypothesized that the bones from both wild type (WT) and KO B6;129 mice would be more responsive to exercise than the bones from C3H mice. To test these hypotheses at 11 weeks of age, following 21 consecutive days of exercise, we investigated cross-sectional geometry, mechanical properties, and tissue composition in the tibiae of male mice bred on B6;129 and C3H backgrounds. This study demonstrated inbred strain-specific compositional and mechanical changes following exercise in WT and KO mice, and showed evidence of genotype-specific changes in bone in response to loading in a gene disruption model. This study further shows that exercise can influence bone tissue composition and/or mechanical integrity without changes in bone geometry. Together, these data suggest that exercise may represent a possible means to alter tissue quality and mechanical deficiencies caused by many diseases of bone. PMID:20033775

AGT M235T and ACE ID polymorphisms and exercise blood pressure in the HERITAGE Family Study.

PubMed

Rankinen, T; Gagnon, J; Pérusse, L; Chagnon, Y C; Rice, T; Leon, A S; Skinner, J S; Wilmore, J H; Rao, D C; Bouchard, C

2000-07-01

We investigated the association between angiotensinogen (AGT) and angiotensin-converting enzyme (ACE) gene polymorphisms and exercise training responses of resting and exercise blood pressure (BP). BP at rest and during submaximal (50 watts) and maximal exercise tests was measured before and after 20 wk of endurance training in 476 sedentary normotensive Caucasian subjects from 99 families. AGT M235T and ACE insertion/deletion polymorphisms were typed with PCR-based methods. Men carrying the AGT MM and MT genotypes showed 3. 7 +/- 0.6 and 3.2 +/- 0.5 (SE) mmHg reductions, respectively, in diastolic BP at 50 watts (DBP(50)), whereas, in the TT homozygotes, the decrease was 0.4 +/- 1.0 mmHg (P = 0.016 for trend, adjusted for age, body mass index, and baseline DBP(50)). Men with the ACE DD genotype showed a slightly greater decrease in DBP(50) (4.4 +/- 0.6 mmHg) than the II and ID genotypes (2.8 +/- 0.7 and 2.4 +/- 0.5 mmHg, respectively, P = 0.050). Furthermore, a significant (P = 0.022) interaction effect between the AGT and ACE genes was noted for DBP(50); the AGT TT homozygotes carrying the ACE D allele showed no response to training. Men with the AGT TT genotype had greater (P = 0.007) diastolic BP (DBP) response to acute maximal exercise at baseline. However, the difference disappeared after the training period. No associations were found in women. These data suggest that, in men, the genetic variation in the AGT locus modifies the responsiveness of submaximal exercise DBP to endurance training, and interactions between the AGT and ACE loci can alter this response.

Effects of chronic nitric oxide synthase inhibition on responses to acute exercise in swine

PubMed Central

McAllister, Richard M.; Newcomer, Sean C.; Pope, Eric R.; Turk, James R.; Laughlin, M. Harold

2012-01-01

Nitric oxide (NO) is potentially involved in several responses to acute exercise. We tested the hypotheses that inhibition of NO formation reduces maximal O2 delivery to muscle, but does not affect O2 utilization by muscle, therefore lowering maximal O2 consumption. To test these hypotheses, swine (~30 kg) drank either tap water (Con, n = 25) or water with NG-nitro-L-arginine methyl ester (8.0 ± 0.4 mg · kg−1 · day−1 for ≥4 wk; LN, n = 24). Treatment efficacy was reflected by higher mean arterial pressure and lower plasma NO metabolite concentration in LN than Con (both P < 0.05). Swine completed two graded treadmill running tests to maximum. In the first test, O2 consumption was determined at rest through maximal exercise intensity. O2 consumption did not differ between groups at rest or at most exercise intensities, including maximum (Con, 40.8 ± 1.8 ml · min−1 · kg−1; LN, 40.4 ± 2.9; not significant). In the second test, tissue-specific blood flows were determined using the radiolabeled-microsphere technique. At rest, blood flows were lower (P < 0.05) in LN compared with Con for a number of tissues, including kidney, adrenal, lung, and several skeletal muscles. During both submaximal and maximal exercise, however, blood flows were similar between Con and LN for all 16 muscles examined; only blood flows to kidney (Con, 99 ± 16 ml · min−1 · 100 g; LN, 55 ± 15; P < 0.05) and pancreas (Con, 25 ± 7; LN, 6 ± 2; P < 0.05) were lower in LN at maximum. Endothelium-dependent, but not -independent, relaxation of renal arterial segments was reduced (P < 0.05) in vitro. These data indicate that exercise-induced increases in muscle blood flows are maintained with chronic inhibition of NO formation and that maximal O2 consumption is therefore preserved. Redundant vasodilatory pathways and/or upregulation of these pathways may underlie these findings. PMID:17975123

Evaluating attentional and affective changes following an acute exercise bout using a modified dot-probe protocol

PubMed Central

BARNES, ROBERT T.; COOMBES, STEPHEN A.; ARMSTRONG, NICOLE B.; HIGGINS, TORRANCE J.; JANELLE, CHRISTOPHER M.

2011-01-01

A large body of literature advocates exercise as a successful intervention for increasing positive affect while also reducing negative affect and anxiety. Questions concerning the mechanisms driving these effects remain unanswered, particularly considering theorized attentional adaptations that may be elicited by acute exercise bouts. We investigated pre- and post-exercise attentional bias to examine possible attentional explanations that may account for these reported changes in affect. On separate visits to the laboratory, 30 high trait anxious participants completed 30 min of exercise on a cycle ergometer at 70% of their heart rate reserve, or completed a 30-min quiet rest protocol. During each intervention, pre-test and post-test modified dot-probe assessments of attentional bias were completed, as were a series of self-report anxiety and affect questionnaires. Attentional bias scores and reaction times were calculated. Post-exercise dot probe performance did not vary significantly as a function of the affective valence of presented stimuli. As hypothesized, however, positive affect and reaction time improved significantly following exercise compared with the pre- and post-rest conditions and the pre-exercise condition, suggesting that exercise facilitates a broadening of attentional scope. Implications of these findings and future directions are discussed within the context of traditional and contemporary theories of dispositional affect and state-specific emotional responses. PMID:20686994

Physiological measures in participants with chronic fatigue syndrome, multiple sclerosis and healthy controls following repeated exercise: a pilot study.

PubMed

Hodges, L D; Nielsen, T; Baken, D

2017-08-07

To compare physiological responses of chronic fatigue syndrome (CFS/ME), multiple sclerosis (MS) and healthy controls (HC) following a 24-h repeated exercise test. Ten CFS, seven MS and 17 age- and gender-matched healthy controls (10, CFS HC; and seven, MS HC) were recruited. Each participant completed a maximal incremental cycle exercise test on day 1 and again 24 h later. Heart rate (HR), blood pressure (BP), rating of perceived exertion (RPE), oxygen consumption (V˙O2), carbon dioxide production and workload (WL) were recorded. Data analysis investigated these responses at anaerobic threshold (AT) and peak work rate (PWR). On day 2, both CFS and MS had significantly reduced max workload compared to HC. On day 2, significant differences were apparent in WL between CFS and CFS HC (93 ± 37 W, 132 ± 42 W, P<0·042). CFS workload decreased on day 2, alongside a decrease in HR but with an increase in V˙O2 (ml   kg   min -1 ). This was in comparison with an increase in WL, HR and V˙O2 for CFS HC. MS demonstrated a decreased WL compared to MS HC on both days of the study (D1 81 ± 30 W, 116 ±30 W; D2 84 ± 29 W, 118 ± 36 W); however, patients with MS were able to achieve a higher WL on day 2 alongside MS HC. These results suggest that exercise exhibits a different physiological response in MS and CFS/ME, demonstrating repeated cardiovascular exercise testing as a valid measure for differentiating between fatigue conditions. © 2017 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

A pragmatic randomised controlled trial of hydrotherapy and land exercises on overall well being and quality of life in rheumatoid arthritis

PubMed Central

Eversden, Lis; Maggs, Fiona; Nightingale, Peter; Jobanputra, Paresh

2007-01-01

Background Hydrotherapy is highly valued by people with rheumatoid arthritis yet few studies have compared the benefits of exercises in heated water against exercises on land. In particular, data on quality of life is rarely reported. This is especially important because patients treated with hydrotherapy often report an enhanced sense of well-being. We report a randomised controlled trial in which we compared the effects of hydrotherapy with exercises on land on overall response to treatment, physical function and quality of life in patients with rheumatoid arthritis. Methods One hundred and fifteen patients with RA were randomised to receive a weekly 30-minute session of hydrotherapy or similar exercises on land for 6 weeks. Our primary outcome was a self-rated global impression of change – a measure of treatment effect on a 7-point scale ranging from 1(very much worse) to 7 (very much better) assessed immediately on completion of treatment. Secondary outcomes including EuroQol health related quality of life, EuroQol health status valuation, HAQ, 10 metre walk time and pain scores were collected at baseline, after treatment and 3 months later. Binary outcomes were analysed by Fisher's exact test and continuous variables by Wilcoxon or Mann-Whitney tests. Results Baseline characteristics of the two groups were comparable. Significantly more patients treated with hydrotherapy (40/46, 87%) were much better or very much better than the patients treated with land exercise (19/40, 47.5%), p < 0.001 Fisher's exact test. Eleven patients allocated land exercise failed to complete treatment compared with 4 patients allocated hydrotherapy (p = 0.09). Sensitivity analyses confirmed an advantage for hydrotherapy if we assumed non-completers would all not have responded (response rates 70% versus 38%; p < 0.001) or if we assumed that non-completers would have had the same response as completers (response rates 82% versus 55% p = 0.002). Ten metre walk time improved after treatment in both cases (median pre-treatment time for both groups combined 10.9 seconds, post-treatment 9.1 s, and 3 months later 9.6 s). There was however no difference between treatment groups. Similarly there were no significant differences between groups in terms of changes to HAQ, EQ-5D utility score, EQ VAS and pain VAS. Conclusion Patients with RA treated with hydrotherapy are more likely to report feeling much better or very much better than those treated with land exercises immediately on completion of the treatment programme. This perceived benefit was not reflected by differences between groups in 10-metre walk times, functional scores, quality of life measures and pain scores. PMID:17331241

A pragmatic randomised controlled trial of hydrotherapy and land exercises on overall well being and quality of life in rheumatoid arthritis.

PubMed

Eversden, Lis; Maggs, Fiona; Nightingale, Peter; Jobanputra, Paresh

2007-03-01

Hydrotherapy is highly valued by people with rheumatoid arthritis yet few studies have compared the benefits of exercises in heated water against exercises on land. In particular, data on quality of life is rarely reported. This is especially important because patients treated with hydrotherapy often report an enhanced sense of well-being. We report a randomised controlled trial in which we compared the effects of hydrotherapy with exercises on land on overall response to treatment, physical function and quality of life in patients with rheumatoid arthritis. One hundred and fifteen patients with RA were randomised to receive a weekly 30-minute session of hydrotherapy or similar exercises on land for 6 weeks. Our primary outcome was a self-rated global impression of change--a measure of treatment effect on a 7-point scale ranging from 1(very much worse) to 7 (very much better) assessed immediately on completion of treatment. Secondary outcomes including EuroQol health related quality of life, EuroQol health status valuation, HAQ, 10 metre walk time and pain scores were collected at baseline, after treatment and 3 months later. Binary outcomes were analysed by Fisher's exact test and continuous variables by Wilcoxon or Mann-Whitney tests. Baseline characteristics of the two groups were comparable. Significantly more patients treated with hydrotherapy (40/46, 87%) were much better or very much better than the patients treated with land exercise (19/40, 47.5%), p < 0.001 Fisher's exact test. Eleven patients allocated land exercise failed to complete treatment compared with 4 patients allocated hydrotherapy (p = 0.09). Sensitivity analyses confirmed an advantage for hydrotherapy if we assumed non-completers would all not have responded (response rates 70% versus 38%; p < 0.001) or if we assumed that non-completers would have had the same response as completers (response rates 82% versus 55% p = 0.002). Ten metre walk time improved after treatment in both cases (median pre-treatment time for both groups combined 10.9 seconds, post-treatment 9.1 s, and 3 months later 9.6 s). There was however no difference between treatment groups. Similarly there were no significant differences between groups in terms of changes to HAQ, EQ-5D utility score, EQ VAS and pain VAS. Patients with RA treated with hydrotherapy are more likely to report feeling much better or very much better than those treated with land exercises immediately on completion of the treatment programme. This perceived benefit was not reflected by differences between groups in 10-metre walk times, functional scores, quality of life measures and pain scores.

Evaluation of two cold thermoregulatory models for prediction of core temperature during exercise in cold water.

PubMed

Castellani, John W; O'Brien, Catherine; Tikuisis, Peter; Sils, Ingrid V; Xu, Xiaojiang

2007-12-01

Cold thermoregulatory models (CTM) have primarily been developed to predict core temperature (T(core)) responses during sedentary immersion. Few studies have examined their efficacy to predict T(core) during exercise cold exposure. The purpose of this study was to compare observed T(core) responses during exercise in cold water with the predicted T(core) from a three-cylinder (3-CTM) and a six-cylinder (6-CTM) model, adjusted to include heat production from exercise. A matrix of two metabolic rates (0.44 and 0.88 m/s walking), two water temperatures (10 and 15 degrees C), and two immersion depths (chest and waist) were used to elicit different rates of T(core) changes. Root mean square deviation (RMSD) and nonparametric Bland-Altman tests were used to test for acceptable model predictions. Using the RMSD criterion, the 3-CTM did not fit the observed data in any trial, whereas the 6-CTM fit the data (RMSD less than standard deviation) in four of eight trials. In general, the 3-CTM predicted a rapid decline in core temperature followed by a plateau. For the 6-CTM, the predicted T(core) appeared relatively tight during the early part of immersion, but was much lower during the latter portions of immersion, accounting for the nonagreement between RMSD and SD values. The 6-CTM was rerun with no adjustment for exercise metabolism, and core temperature and heat loss predictions were tighter. In summary, this study demonstrated that both thermoregulatory models designed for sedentary cold exposure, currently, cannot be extended for use during partial immersion exercise in cold water. Algorithms need to be developed to better predict heat loss during exercise in cold water.

The characteristics and effects of motivational music in exercise settings: the possible influence of gender, age, frequency of attendance, and time of attendance.

PubMed

Priest, D L; Karageorghis, C I; Sharp, N C C

2004-03-01

The purpose of the present study was to investigate the characteristics and effects of motivational music in British gymnasia. The secondary purpose was to determine whether the characteristics and effects of motivational music were invariant in relation to gender, age, frequency of gymnasium attendance, and the time of day at which exercise participants attended gymnasia. Participants (n=532) from 29 David Lloyd Leisure exercise facilities across Britain responded to a questionnaire that was designed to assess music preferences during exercise via 2 open-ended questions and 1 scaled-response item. A content analysis of the questionnaire data yielded 45 analytic properties that were grouped into the following categories: specific music factors, general music factors, music programme factors, delivery factors, televisual factors, personal factors, contextual factors, and psychophysical response factors. The relative incidence of these analytic properties across gender groups (male/female), age groups (16-26 y, 27-34 y, 35-45 y, 46+ y), frequency of attendance groups (low, medium, high), and time of attendance groups (morning, afternoon, evening) was tested by use of chi(2) analyses. Of the personal variables tested, age exerted the greatest influence on musical preference during exercise; older participants expressed a preference for quieter, slower, and generally less overtly stimulative music. Music programmes that are prescribed to accompany exercise should be varied in terms of musical idiom and date of release. Such programmes will account for the preferences of different groups of exercise participants that attend gymnasia at different times of the day. Further, the music chosen should be characterised by a strong rhythmical component.

Improvement of insulin sensitivity in response to exercise training in type 2 diabetes mellitus is associated with vascular endothelial growth factor A expression.

PubMed

Wagner, Henrik; Fischer, Helene; Degerblad, Marie; Alvarsson, Michael; Gustafsson, Thomas

2016-09-01

Insulin sensitivity changes in response to exercise training demonstrate a large variation. Vascular endothelial growth factor A could promote increased insulin sensitivity through angiogenesis. We investigated associations between changes in expression of key genes and insulin sensitivity, aerobic capacity and glycaemic control following exercise training in diabetes mellitus type 2. Subjects with diabetes mellitus type 2 underwent 12 weeks of structured exercise. Euglycaemic clamp, exercise test and HbA1c were performed. Muscle biopsies were obtained for mRNA expression. A total of 16 subjects completed the study. Change in vascular endothelial growth factor A expression was positively associated with an increase in insulin sensitivity (p = 0.004) and with a decrease in HbA1c (p = 0.034). Vascular endothelial growth factor A receptor-1 expression showed similar associations. The variation in physical adaptation to exercise training in diabetes mellitus type 2 was associated with changes in expression of vascular endothelial growth factor A in muscle. This difference in induced gene expression could contribute to the variation in exercise training effects on insulin sensitivity. Measures of capillary blood flow need to be assessed in future studies. © The Author(s) 2016.

Energy expenditure and physiological responses during walking on a treadmill and moving on the Torqway vehicle.

PubMed

Maciejczyk, Marcin; Wiecek, Magdalena; Szymura, Jadwiga; Szygula, Zbigniew

2016-01-01

One of the new products which can be used to increase physical activity and energy expenditure is the Torqway vehicle, powered by the upper limbs. The aim of this study was to (1) assess the usefulness and repeatability of the Torqway vehicle for physical exercise, (2) compare energy expenditure and physiological responses during walking on a treadmill and during physical effort while moving on the Torqway at a constant speed. The participants (11 men, aged 20.2 ± 1.3) performed the incremental test and submaximal exercises (walking on the treadmill and moving on the Torqway vehicle at the same speed). Energy expenditure during the exercise on the Torqway was significantly higher (p = 0.001) than during the walking performed at the same speed. The intensity of the exercise performed on the Torqway expressed as %VO2max and %HRmax was significantly ( p < 0.001) higher than during walking (respectively: 35.0 ± 6.0 vs. 29.4 ± 7.4 %VO2max and 65.1 ± 7.3 vs. 47.2 ± 7.4 %HRmax). Exercise on the Torqway vehicle allows for the intensification of the exercise at a low movement speed, comparable to walking. Moving on the Torqway vehicle could be an effective alternative activity for physical fitness and exercise rehabilitation programs.

Association of von Willebrand factor blood levels with exercise hypertension.

PubMed

Nikolic, Sonja B; Adams, Murray J; Otahal, Petr; Edwards, Lindsay M; Sharman, James E

2015-05-01

A hypertensive response to moderate intensity exercise (HRE) is associated with increased cardiovascular risk. The mechanisms of an HRE are unclear, although previous studies suggest this may be due to haemostatic and/or haemodynamic factors. We investigated the relationships between an HRE with haemostatic and hemodynamic indices. Sixty-four participants (57 ± 10 years, 71 % male) with indication for exercise stress testing underwent cardiovascular assessment at rest and during moderate intensity exercise, from which 20 participants developed an HRE (defined as moderate exercise systolic BP ≥ 170 mmHg/men and ≥ 160 mmHg/women). Rest, exercise and post-exercise blood samples were analysed for haemostatic markers, including von Willebrand factor (vWf), and haemodynamic measures of brachial and central blood pressure (BP), aortic stiffness and systemic vascular resistance index (SVRi). HRE participants had higher rest vWf compared with normotensive response to exercise (NRE) participants (1,927 mU/mL, 95 % CI 1,240-2,615, vs. 1,129 mU/mL, 95 % CI 871-1,386; p = 0.016). vWf levels significantly decreased from rest to post-exercise in HRE participants (p = 0.005), whereas vWf levels significantly increased from rest to exercise in NRE participants (p = 0.030). HRE participants also had increased triglycerides, rest BP, aortic stiffness and exercise SVRi (p < 0.05 for all). Rest vWf predicted exercise brachial systolic BP (β = 0.220, p = 0.043; adjusted R (2) = 0.451, p < 0.001) independent of age, sex, body mass index, triglycerides, rest brachial systolic BP and aortic stiffness. Increased rest blood levels of vWf are independently associated with moderate intensity exercise systolic BP. These findings implicate abnormalities in haemostasis as a possible factor contributing to HRE at moderate intensity.

Hormonal responses during a prolonged military field exercise with variable exercise intensity.

PubMed

Kyröläinen, Heikki; Karinkanta, Jari; Santtila, Matti; Koski, Harri; Mäntysaari, Matti; Pullinen, Teemu

2008-03-01

The purpose of the present study was to test the hypothesis that the magnitude of hormonal concentration alterations during a prolonged military field exercise with constant energy intake (EI) is influenced by changes in energy deficit (ED) induced by varying the exercise intensity. Basal serum hormone concentrations were measured in a group of healthy young male volunteers (n = 7) during a 20-day field exercise. During the first week of the exercise, the average ED was 4,000 kcal/day (P-I), in the second week only 450 kcal/day (P-II), and in the last week 1,000 kcal/day (P-III). During the first 5 days of the field exercise, significant increases in cortisol (COR, +32%) and growth hormone (GH, +616%) concentrations were observed, while insulin (INS, -70%), total testosterone (TES, -27%), free testosterone (TES(free), -26%) decreased. However, after these initial responses, COR and GH returned to the pre-exercise level by the beginning of P-II. Also TES and TES(free) recovered to the pre-exercise level by the beginning of P-III, and INS by the end of P-III. The concentration of TES (+29%) increased above the pre-exercise level by the beginning of P-III. Serum thyroxin (T(4)) concentration was significantly lesser (-12%) and urine urea concentration significantly higher (+78%) after the field exercise than before it. Therefore, it can be concluded that the lower levels of ED in the second and third phase (ED <1,000 kcal/day) allowed recovery of hormonal changes observed in the first phase with ED much greater than 1,000 kcal/day.

Psychophysiological Responses to Group Exercise Training Sessions: Does Exercise Intensity Matter?

PubMed

Vandoni, Matteo; Codrons, Erwan; Marin, Luca; Correale, Luca; Bigliassi, Marcelo; Buzzachera, Cosme Franklim

2016-01-01

Group exercise training programs were introduced as a strategy for improving health and fitness and potentially reducing dropout rates. This study examined the psychophysiological responses to group exercise training sessions. Twenty-seven adults completed two group exercise training sessions of moderate and vigorous exercise intensities in a random and counterbalanced order. The %HRR and the exertional and arousal responses to vigorous session were higher than those during the moderate session (p<0.05). Consequently, the affective responses to vigorous session were less pleasant than those during moderate session (p<0.05). These results suggest that the psychophysiological responses to group exercise training sessions are intensity-dependent. From an adherence perspective, interventionists are encouraged to emphasize group exercise training sessions at a moderate intensity to maximize affective responses and to minimize exertional responses, which in turn may positively affect future exercise behavior.

Southeastern Center for Emerging Biologic Threats Tabletop Exercise: Foodborne Toxoplasmosis Outbreak on College Campuses

PubMed Central

Morris, J. Glenn; Greenspan, Allison; Howell, Kelly; Mitchell, Joanne; Jones, Jeffrey L.; Potter, Morris; Isakov, Alexander; Woods, Christopher; Hughes, James M.

2012-01-01

The use of tabletop exercises as a tool in emergency preparedness and response has proven to be an effective means of assessing readiness for unexpected events. Whereas most exercise developers target a population in a defined space (eg, state, county, metropolitan area, hospital), the Southeastern Center for Emerging Biologic Threats (SECEBT) conducted an innovative tabletop exercise involving an unusual foodborne outbreak pathogen, targeting public health agencies and academic institutions in 7 southeastern states. The exercise tested the ability of participants to respond to a simulated foodborne disease outbreak affecting the region. The attendees represented 4 federal agencies, 9 state agencies, 6 universities, 1 nonprofit organization, and 1 private corporation. The goals were to promote collaborative relationships among the players, identify gaps in plans and policies, and identify the unique contributions of each organization—and notably academic institutions—to outbreak recognition, investigation, and control. Participants discussed issues and roles related to outbreak detection and management, risk communication, and coordination of policies and responsibilities before, during, and after an emergency, with emphasis on assets of universities that could be mobilized during an outbreak response. The exercise generated several lessons and recommendations identified by participants and evaluators. Key recommendations included a need to establish trigger points and protocols for information sharing and alerts among public health, academic, and law enforcement; to establish relationships with local, state, and federal stakeholders to facilitate communications during an emergency; and to catalogue and leverage strengths, assets, and priorities of academic institutions to add value to outbreak responses. PMID:22283568

Effects of Arm Ergometry Exercise on the Reaction, Movement and Response Times of the Lower Extremities.

ERIC Educational Resources Information Center

Israel, Richard G.

A study determined the effects of fatigue produced in the upper extremities on the reaction time, movement time, and response time of the lower extremities in 30 male subjects, 19-25 years old. Each subject participated in a 10 trial practice session one day prior to the experiment and immediately preceding the pre-test. The pre-test consisted of…

Stretch-activated ion channel blockade attenuates adaptations to eccentric exercise.

PubMed

Butterfield, Timothy A; Best, Thomas M

2009-02-01

The purpose of this study was to test the hypothesis that stretch-activated ion channel (SAC) function is essential for the repeated bout effect (RBE) in skeletal muscle. Specifically, we investigated if daily injections of streptomycin (a known SAC blocker) would abrogate the muscle's adaptive resistance to the damaging effects of eccentric exercise over a 4-wk period. Furthermore, we hypothesized that the lack of an RBE would be due to the lack of functional adaptations that typically result from repeated bouts of eccentric exercise, including increased peak isometric torque, muscle hypertrophy, and rightward shift of the torque-angle relationship. Twelve New Zealand white rabbits were each subjected to 12 bouts of eccentric exercise over a 4-wk period while receiving either daily injections of streptomycin or sham injections. Although blocking the SAC function completely eliminated the expected adaptive response in biomechanical parameters during the exercise regimen, there remained evidence of an acquired RBE, albeit with an attenuated response when compared with the muscles with intact SAC function. Blocking sarcolemmal SAC eliminates functional adaptations of muscle after eccentric exercise. In the absence of SAC function, muscles subjected to chronic eccentric exercise still exhibit some degree of the RBE. As such, it appears that the signaling cascade that results in functional, biomechanical adaptations associated with the RBE during eccentric exercise is dependent upon intact SAC function.

Noninvasive stress testing - Methodology for elimination of the phonocardiogram

NASA Technical Reports Server (NTRS)

Spodick, D. H.; Lance, V. Q.

1976-01-01

Measurement by systolic time intervals (STI) of cardiac responses requires extremely careful recording during actual stress test performance. Previous work indicated no significant changes in the pulse transmission time (PTT) during exercise and other challenges. Since external STI depend on the carotid pulse offset by the PTT as an aortic curve equivalent, stable PTT implies that timing of the carotid upstroke and the carotid incisura would respectively track the pre-ejection period and the aortic incisura. In ten subjects, STIs were recorded at supine rest, sitting, standing, during prompt and sustained squatting and during isometric and dynamic exercise. The results demonstrated the tracking of both points. Coefficients of correlation and of determination were uniformly high for all challenges except isometric handgrip (IHG). Since left ventricular ejection time is obtained directly from the pulse curve, with the exception of IHG, STI responses during stress testing can be measured without a phonocardiogram.

Trend Extraction in Functional Data of Amplitudes of R and T Waves in Exercise Electrocardiogram

NASA Astrophysics Data System (ADS)

Cammarota, Camillo; Curione, Mario

The amplitudes of R and T waves of the electrocardiogram (ECG) recorded during the exercise test show both large inter- and intra-individual variability in response to stress. We analyze a dataset of 65 normal subjects undergoing ambulatory test. We model the dataset of R and T series in the framework of functional data, assuming that the individual series are realizations of a non-stationary process, centered at the population trend. We test the time variability of this trend computing a simultaneous confidence band and the zero crossing of its derivative. The analysis shows that the amplitudes of the R and T waves have opposite responses to stress, consisting respectively in a bump and a dip at the early recovery stage. Our findings support the existence of a relationship between R and T wave amplitudes and respectively diastolic and systolic ventricular volumes.

Cardiovascular Response to Recreational Hockey in Middle-Aged Men.

PubMed

Goodman, Zack A; Thomas, Scott G; Wald, Robert C; Goodman, Jack M

2017-06-15

The present study examined the hemodynamic response to recreational pick-up hockey relative to maximal exercise testing in middle-aged men. A total of 23 men with a mean age of 53 ± 7 years were studied. Graded exercise testing on a cycle ergometer determined maximal oxygen consumption, blood pressure (BP), and heart rate (HR). Ambulatory BP and Holter electrocardiographic monitoring was performed during one of their weekly hockey games (mean duration = 45 ± 7.2 minutes): for "On-Ice" responses (PLAY; data recorded while standing immediately after a shift; 8.0 ± 1.4 shifts per game) and during seated recovery (BENCH), 15 minutes after the game. On-Ice HRs and BPs were significantly higher than values obtained during maximal cycle exercise, respectively (HR 174 ± 8.9 vs 163 ± 11.0 beats/min) (systolic blood pressure 202 ± 20 vs 173 ± 31 mm Hg; p <0.05). Both systolic and diastolic blood pressures decreased significantly throughout the duration of the game, whereas HR increased from 139 ± 20 to 155 ± 16 beats/min during the game. The myocardial oxygen demand (myocardial time tension index) increased significantly during PLAY concurrent with a decrease in estimated myocardial oxygen supply (diastolic pressure time index), with the endocardial viability ratio during PLAY demonstrating a significant decrease during the third quarter of the game (1.25 ± 0.24) versus the first quarter (1.56 ± 0.30), which remained depressed 15 minutes post-game (p <0.05). In conclusion, recreational pick-up hockey in middle-aged men is an extremely vigorous interval exercise with increasing relative intensity as the game progresses. Hockey elicits peak BPs and HRs that can exceed values observed during maximal exercise testing and is characterized by progressive increases in myocardial oxygen demand and lowered supply during PLAY and BENCH time. Given the progressive and high cardiovascular demands, caution is warranted when estimating the cardiovascular demands of hockey from clinical stress testing, particularly in those whom coronary reserve may be compromised. Copyright © 2017 Elsevier Inc. All rights reserved.

Comparison of myocardial ischemia during intense mental stress using flight simulation in airline pilots with coronary artery disease to that produced with conventional mental and treadmill exercise stress testing.

PubMed

Doorey, Andrew; Denenberg, Barry; Sagar, Vidya; Hanna, Tracy; Newman, Jack; Stone, Peter H

2011-09-01

Mental stress increases cardiovascular morbidity and mortality. Although laboratory mental stress often causes less myocardial ischemia than exercise stress (ES), it is unclear whether mental stress is intrinsically different or differences are due to less hemodynamic stress with mental stress. We sought to evaluate the hemodynamic and ischemic response to intense realistic mental stress created by modern flight simulators and compare this response to that of exercise treadmill testing and conventional laboratory mental stress (CMS) testing in pilots with coronary disease. Sixteen airline pilots with angiographically documented coronary disease and documented myocardial ischemia during ES were studied using maximal treadmill ES, CMS, and aviation mental stress (AMS) testing. AMS testing was done in a sophisticated simulator using multiple system failures as stressors. Treadmill ES testing resulted in the highest heart rate, but AMS caused a higher blood pressure response than CMS. Maximal rate-pressure product was not significantly different between ES and AMS (25,646 vs 23,347, p = 0.08), although these were higher than CMS (16,336, p <0.0001). Despite similar hemodynamic stress induced by ES and AMS, AMS resulted in significantly less ST-segment depression and nuclear ischemia than ES. Differences in induction of ischemia by mental stress compared to ES do not appear to be due to the creation of less hemodynamic stress. In conclusion, even with equivalent hemodynamic stress, intense realistic mental stress induced by flight simulators results in significantly less myocardial ischemia than ES as measured by ST-segment depression and nuclear ischemia. Copyright © 2011 Elsevier Inc. All rights reserved.

The Effects of Acute High-Intensity Interval Training on Hematological Parameters in Sedentary Subjects.

PubMed

Belviranli, Muaz; Okudan, Nilsel; Kabak, Banu

2017-07-19

The objective of the study was to determine the effects of acute high-intensity interval training (HIIT) on hematological parameters in sedentary men. Ten healthy, non-smoker, and sedentary men aged between 18 and 24 years participated in the study. All subjects performed four Wingate tests with 4 min intervals between the tests. Blood samples were collected at pre-exercise, immediately after, 3 and 6 h after the fourth Wingate test. Hematological parameters were analyzed in these samples. The results showed that hematocrit percentage, hemoglobin values, red cell count, mean cell volume, platelet count, total white cell count, and counts of the white cell subgroups increased immediately after the acute HIIT and their values began to return to resting levels 3 h after exercise, and completely returned to resting levels 6 h after exercise. In conclusion, acute HIIT causes an inflammatory response in blood.

Perceiving Cardiac Rehabilitation Staff as Mainly Responsible for Exercise: A Dilemma for Future Self-Management.

PubMed

Flora, Parminder K; McMahon, Casey J; Locke, Sean R; Brawley, Lawrence R

2018-03-01

Cardiac rehabilitation (CR) exercise therapy facilitates patient recovery and better health following a cardiovascular event. However, post-CR adherence to self-managed (SM)-exercise is suboptimal. Part of this problem may be participants' view of CR staff as mainly responsible for help and program structure. Does post-CR exercise adherence for those perceiving high CR staff responsibility suffer as a consequence? Participants in this prospective, observational study were followed over 12 weeks of CR and one month afterward. High perceived staff responsibility individuals were examined for a decline in the strength of adherence-related social cognitions and exercise. Those high and low in perceived staff responsibility were also compared. High perceived staff responsibility individuals reported significant declines in anticipated exercise persistence (d = .58) and number of different SM-exercise options (d = .44). High versus low responsibility comparisons revealed a significant difference in one-month post-CR SM-exercise volume (d = .67). High perceived staff responsibility individuals exercised half of the amount of low responsibility counterparts at one month post-CR. Perceived staff responsibility and CR SRE significantly predicted SM-exercise volume, R 2 adj = .10, and persistence, R 2 adj = .18, one month post-CR. Viewing helpful well-trained CR staff as mainly responsible for participant behavior may be problematic for post-CR exercise maintenance among those more staff dependent. © 2017 The International Association of Applied Psychology.

Older women exhibit greater airway 8-isoprostane responses to strenuous exercise compared with older men and younger controls.

PubMed

Kurti, Stephanie P; Emerson, Sam R; Smith, Joshua R; Rosenkranz, Sara K; Alexander, Samantha A; Lovoy, Garrett M; Harms, Craig A

2018-05-01

Development of late-onset respiratory diseases is associated with elevated 8-isoprostane, a marker of oxidative stress, in the airways. However, sex differences exist in development of these diseases. Using an exhaustive exercise bout as a physiological stressor may elucidate whether there is a sex difference with aging in pre- to postexercise airway 8-isoprostane generation. The purpose of this study was to determine whether older women exhibit a greater airway 8-isoprostane response to exhaustive exercise compared with older men and younger controls. Thirty-six individuals completed the study (12 postmenopausal older women (OW) and 12 age-matched older men (OM), 65 ± 4 years of age; and 12 younger controls (YC), 21 ± 2 years of age). Baseline measurements included exhaled breath condensate (EBC) for assessment of airway 8-isoprostane and standard pulmonary function tests (PFTs) to assess forced expiratory volume in 1-s (FEV 1 ), forced vital capacity (FVC), FEV 1 /FVC, and forced expiratory flow at 25%-75% of FVC. Subjects then performed a peak oxygen uptake test to exhaustion on a cycle ergometer. Immediately postexercise, PFTs and EBC were performed. The generation of airway 8-isoprostane from pre- to postexercise was greater in OW compared with OM and YC (p < 0.01), increasing ∼74% ± 77% in OW, while decreasing in OM (∼12% ± 50%) and YC (∼20.9% ± 30%). The OW exhibited a greater airway 8-isoprostane response to exhaustive exercise compared with OM and YC, which may suggest that sex differences in oxidative stress generation following exhaustive exercise may provide a mechanistic rationale for sex differences in late-onset respiratory diseases.

Force properties of skinned cardiac muscle following increasing volumes of aerobic exercise in rats.

PubMed

Boldt, Kevin Rudi; Rios, Jaqueline Lourdes; Joumaa, Venus; Herzog, Walter

2018-05-03

The positive effects of chronic endurance exercise training on health and performance have been well documented. These positive effects have been evaluated primarily at the structural level, and work has begun to evaluate mechanical adaptations of the myocardium. However, it remains poorly understood how the volume of exercise training affects cardiac adaptation. In order to gain some understanding, we subjected three-month-old Sprague-Dawley rats (N=23) to treadmill running for eleven weeks at one of three exercise volumes (moderate, high, and extra high). Following training, hearts were excised and mechanical testing was completed on skinned trabecular fiber bundles. Performance on a maximal fitness test was dose-dependent upon training volume, where greater levels of training led to greater performance. No differences were observed between animals from any group for active stress production. Heart mass and passive stress increases in a dose-dependent manner for animals in the control, moderate, and high duration groups. However, hearts from animals in the extra high duration group presented with inhibited responses for heart mass and passive stress, despite performing greatest on a graded treadmill fitness test. These results suggest that heart mass and passive stress adapt in a dose-dependent manner, until exercise becomes excessive and adaptation is inhibited. Our findings are in agreement with the beneficial role exercise has in cardiac adaptation. However, excessive exercise comes with risks of maladaptation which must be weighed against the desire to increase performance.

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

PubMed

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

2009-06-01

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

Does a 20-week aerobic exercise training programme increase our capabilities to buffer real-life stressors? A randomized, controlled trial using ambulatory assessment.

PubMed

von Haaren, Birte; Ottenbacher, Joerg; Muenz, Julia; Neumann, Rainer; Boes, Klaus; Ebner-Priemer, Ulrich

2016-02-01

The cross-stressor adaptation hypothesis suggests that regular exercise leads to adaptations in the stress response systems that induce decreased physiological responses to psychological stressors. Even though an exercise intervention to buffer the detrimental effects of psychological stressors on health might be of utmost importance, empirical evidence is mixed. This may be explained by the use of cross-sectional designs and non-personally relevant stressors. Using a randomized controlled trial, we hypothesized that a 20-week aerobic exercise training does reduce physiological stress responses to psychological real-life stressors in sedentary students. Sixty-one students were randomized to either a control group or an exercise training group. The academic examination period (end of the semester) served as a real-life stressor. We used ambulatory assessment methods to assess physiological stress reactivity of the autonomic nervous system (heart rate variability: LF/HF, RMSSD), physical activity and perceived stress during 2 days of everyday life and multilevel models for data analyses. Aerobic capacity (VO2max) was assessed pre- and post-intervention via cardiopulmonary exercise testing to analyze the effectiveness of the intervention. During real-life stressors, the exercise training group showed significantly reduced LF/HF (β = -0.15, t = -2.59, p = .01) and increased RMSSD (β = 0.15, t = 2.34, p = .02) compared to the control group. Using a randomized controlled trial and a real-life stressor, we could show that exercise appears to be a useful preventive strategy to buffer the effects of stress on the autonomic nervous system, which might result into detrimental health outcomes.

Preliminary evidence that exercise dependence is associated with blunted cardiac and cortisol reactions to acute psychological stress.

PubMed

Heaney, Jennifer L J; Ginty, Annie T; Carroll, Douglas; Phillips, Anna C

2011-02-01

Low or blunted cardiovascular and cortisol reactions to acute psychological stress have been shown to characterise those with a tobacco or alcohol dependency. The present study tested the hypothesis that exercise dependency would be similarly associated with blunted reactivity. Young female exercisers (N=219) were screened by questionnaire for exercise dependence. Ten women with probable exercise dependence and 10 non dependent controls were selected for laboratory stress testing. Cardiovascular activity and salivary cortisol were measured at rest and in response to a 10-min mental arithmetic stress task. The exercise dependent women showed blunted cardiac reactions to the stress task and blunted cortisol at 10, 20, and 30 minute post stress exposure. These effects could not be accounted for in terms of group differences in stress task performance, nor could the cardiac effects be attributed to group differences in cardio-respiratory fitness. It would seem that low stress reactivity is characteristic of a wide range of dependencies, and is not confined to substance dependence. Our results offer further support for the hypothesis that blunted stress reactivity may be a peripheral marker of a central motivational dysregulation. Copyright © 2010 Elsevier B.V. All rights reserved.

Exercise training improves function of circulating angiogenic cells in patients with chronic heart failure.

PubMed

Van Craenenbroeck, Emeline M; Hoymans, Vicky Y; Beckers, Paul J; Possemiers, Nadine M; Wuyts, Kurt; Paelinck, Bernard P; Vrints, Christiaan J; Conraads, Viviane M

2010-09-01

Alterations in circulating angiogenic cells (CAC) and endothelial progenitor cells (EPC), known to contribute to endothelial repair, could explain the reversal of endothelial function in response to exercise training. Moreover, training-induced vascular remodeling might affect the acute response of EPC and CAC following a single exercise bout. We studied the impact of exercise training on CAC function and numbers of CD34(+)/KDR(+) EPC in patients with chronic heart failure (CHF) and we assessed the effect of acute exercise on CAC and EPC in sedentary and trained patients. Twenty-one sedentary CHF patients underwent 6-month exercise training and were compared to a non-trained control group (n = 17) and 10 healthy age-matched subjects. At baseline and follow-up, flow-mediated dilation was assessed and graded exercise testing (GXT) was performed. Before and immediately after GXT, CAC migratory capacity was assessed in vitro and circulating CD34(+)/KDR(+) EPC were quantified using flow cytometry. At baseline, CAC migration was significantly impaired in sedentary CHF patients but normalized acutely after GXT. Training corrected endothelial dysfunction, which coincided with a 77% increase in CAC migration (P = 0.0001). Moreover, the GXT-induced improvement detected at baseline was no longer observed after training. Numbers of CD34(+)/KDR(+) EPC increased following 6-month exercise training (P = 0.021), but were not affected by GXT, either prior or post-training. In conclusion, the present findings demonstrate for the first time that exercise training in CHF reverses CAC dysfunction and increases numbers of CD34(+)/KDR(+) EPC, which is accompanied by improvement of peripheral endothelial function. The acute exercise-induced changes in CAC function wane with exercise training, suggesting that repetitive exercise bouts progressively lead to functional endothelial repair.

Systemic Exercise-Induced Hypoalgesia Following Isometric Exercise Reduces Conditioned Pain Modulation.

PubMed

Alsouhibani, Ali; Vaegter, Henrik Bjarke; Hoeger Bement, Marie

2018-04-03

Physically active individuals show greater conditioned pain modulation (CPM) compared with less active individuals. Understanding the effects of acute exercise on CPM may allow for a more targeted use of exercise in the management of pain. This study investigated the effects of acute isometric exercise on CPM. In addition, the between-session and within-session reliability of CPM was investigated. Experimental, randomized crossover study. Laboratory at Marquette University. Thirty healthy adults (19.3±1.5 years, 15 males). Subjects underwent CPM testing before and after isometric exercise (knee extension, 30% maximum voluntary contraction for three minutes) and quiet rest in two separate experimental sessions. Pressure pain thresholds (PPTs) at the quadriceps and upper trapezius muscles were assessed before, during, and after ice water immersions. PPTs increased during ice water immersion (i.e., CPM), and quadriceps PPT increased after exercise (P < 0.05). CPM decreased similarly following exercise and quiet rest (P > 0.05). CPM within-session reliability was fair to good (intraclass correlation coefficient [ICC] = 0.43-0.70), and the between-session reliability was poor (ICC = 0.20-0.35). Due to the variability in the systemic exercise-induced hypoalgesia (EIH) response, participants were divided into systemic EIH responders (N = 9) and nonresponders (N = 21). EIH responders experienced attenuated CPM following exercise (P = 0.03), whereas the nonresponders showed no significant change (P > 0.05). Isometric exercise decreased CPM in individuals who reported systemic EIH, suggesting activation of shared mechanisms between CPM and systemic EIH responses. These results may improve the understanding of increased pain after exercise in patients with chronic pain and potentially attenuated CPM.

Blunted heart rate recovery is improved following exercise training in overweight adults with obstructive sleep apnea.

PubMed

Kline, Christopher E; Crowley, E Patrick; Ewing, Gary B; Burch, James B; Blair, Steven N; Durstine, J Larry; Davis, J Mark; Youngstedt, Shawn D

2013-08-20

Obstructive sleep apnea (OSA) predisposes individuals to cardiovascular morbidity, and cardiopulmonary exercise test (CPET) markers prognostic for cardiovascular disease have been found to be abnormal in adults with OSA. Due to the persistence of OSA and its cardiovascular consequences, whether the cardiovascular adaptations normally conferred by exercise are blunted in adults not utilizing established OSA treatment is unknown. The aims of this study were to document whether OSA participants have abnormal CPET responses and determine whether exercise modifies these CPET markers in individuals with OSA. The CPET responses of 43 sedentary, overweight adults (body mass index [BMI]>25) with untreated OSA (apnea-hypopnea index [AHI]≥ 15) were compared against matched non-OSA controls (n=9). OSA participants were then randomized to a 12-week exercise training (n=27) or stretching control treatment (n=16), followed by a post-intervention CPET. Measures of resting, exercise, and post-exercise recovery heart rate (HRR), blood pressure, and ventilation, as well as peak oxygen consumption (VO(2peak)), were obtained. OSA participants had blunted HRR compared to non-OSA controls at 1 (P=.03), 3 (P=.02), and 5-min post-exercise (P=.03). For OSA participants, exercise training improved VO2 peak (P=.04) and HRR at 1 (P=.03), 3 (P<.01), and 5-min post-exercise (P<.001) compared to control. AHI change was associated with change in HRR at 5-min post-exercise (r=-.30, P<.05), but no other CPET markers. These results suggest that individuals with OSA have autonomic dysfunction, and that exercise training, by increasing HRR and VO2 peak, may attenuate autonomic imbalance and improve functional capacity independent of OSA severity reduction. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Blunted Heart Rate Recovery Is Improved Following Exercise Training in Overweight Adults with Obstructive Sleep Apnea

PubMed Central

Kline, Christopher E.; Crowley, E. Patrick; Ewing, Gary B.; Burch, James B.; Blair, Steven N.; Durstine, J. Larry; Davis, J. Mark; Youngstedt, Shawn D.

2012-01-01

Background Obstructive sleep apnea (OSA) predisposes individuals to cardiovascular morbidity, and cardiopulmonary exercise test (CPET) markers prognostic for cardiovascular disease have been found to be abnormal in adults with OSA. Due to the persistence of OSA and its cardiovascular consequences, whether the cardiovascular adaptations normally conferred by exercise are blunted in adults not utilizing established OSA treatment is unknown. The aims of this study were to document whether OSA participants have abnormal CPET responses and determine whether exercise modifies these CPET markers in individuals with OSA. Methods The CPET responses of 43 sedentary, overweight adults (body mass index [BMI]>25) with untreated OSA (apnea-hypopnea index [AHI]≥15) were compared against matched non-OSA controls (n=9). OSA participants were then randomized to a 12-week exercise training (n=27) or stretching control treatment (n=16), followed by a post-intervention CPET. Measures of resting, exercise, and post-exercise recovery heart rate (HRR), blood pressure, and ventilation, as well as peak oxygen consumption (VO2peak), were obtained. Results OSA participants had blunted HRR compared to non-OSA controls at 1 (P=.03), 3 (P=.02), and 5 min post-exercise (P=.03). For OSA participants, exercise training improved VO2peak (P=.04) and HRR at 1 (P=.03), 3 (P<.01), and 5 min post-exercise (P<.001) compared to control. AHI change was associated with change in HRR at 5-min post-exercise (r=−.30, P<.05), but no other CPET markers. Conclusions These results suggest that individuals with OSA have autonomic dysfunction, and that exercise training, by increasing HRR and VO2peak, may attenuate autonomic imbalance and improve functional capacity independent of OSA severity reduction. PMID:22572632

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

Volcano crisis response at Yellowstone volcanic complex - after-action report for exercise held at Salt Lake City, Utah, November 15, 2011

USGS Publications Warehouse

Pierson, Thomas C.; Driedger, Carolyn L.; Tilling, Robert I.

2013-01-01

A functional tabletop exercise was run on November 14-15, 2011 in Salt Lake City, Utah, to test crisis response capabilities, communication protocols, and decision-making by the staff of the multi-agency Yellowstone Volcano Observatory (YVO) as they reacted to a hypothetical exercise scenario of accelerating volcanic unrest at the Yellowstone caldera. The exercise simulated a rapid build-up of seismic activity, ground deformation, and hot-spring water-chemistry and temperature anomalies that culminated in a small- to moderate-size phreatomagmatic eruption within Yellowstone National Park. The YVO scientific team's responses to the unfolding events in the scenario and to simulated requests for information by stakeholders and the media were assessed by (a) the exercise organizers; (b) several non-YVO scientists, who observed and queried participants, and took notes throughout the exercise; and (c) the participants themselves, who kept logs of their actions during the exercise and later participated in a group debriefing session and filled out detailed questionnaires. These evaluations were tabulated, interpreted, and summarized for this report, and on the basis of this information, recommendations have been made. Overall, the YVO teams performed their jobs very well. The exercise revealed that YVO scientists were able to successfully provide critical hazards information, issue information statements, and appropriately raise alert levels during a fast-moving crisis. Based on the exercise, it is recommended that several measures be taken to increase YVO effectiveness during a crisis: 1. Improve role clarification within and between YVO science teams. 2. Improve communications tools and protocols for data-sharing and consensus-building among YVO scientists, who are geographically and administratively dispersed among various institutions across the United States. 3. Familiarize YVO staff with Incident Command System (ICS) procedures and protocols, and provide more in-depth training to appropriate staff members, as needed. 4. Train all science team members in the use of all analytical and computational tools available to them, in order to maximize effectiveness of teams in tracking and interpreting possible accelerating unrest at Yellowstone. Desirable pre-crisis preparations include: (a) updating a catalog of existing map and information products (and identifying additional products) that would be helpful during a crisis; (b) creating "to do" lists of early-crisis tasks for each scientific team; (c) coordinating radio frequencies among partner agencies; and (d) brief training on and promotion of the internal YVO Web log as a repository for scientific observations, data, photographs, and other material to be shared among YVO scientific teams during a crisis. This exercise was designed as an opportunity to practice response to a fast-developing volcano crisis and to test for organizational and procedural weaknesses that could emerge during a real crisis. This report is based upon the observations of the exercise organizers during the one-day exercise and upon written evaluations by the participants. It does not attempt to evaluate any other aspect of YVO or the scientific expertise of any of the highly competent YVO staff. Participants unanimously found the exercise to be helpful for improving their response capabilities, and it is our hope that the report will be a starting point for internal discussions that will make YVO even better-prepared for some future volcano crisis.

Cardiorespiratory fitness modulates the acute flow-mediated dilation response following high-intensity but not moderate-intensity exercise in elderly men.

PubMed

Bailey, Tom G; Perissiou, Maria; Windsor, Mark; Russell, Fraser; Golledge, Jonathan; Green, Daniel J; Askew, Christopher D

2017-05-01

Impaired endothelial function is observed with aging and in those with low cardiorespiratory fitness (V̇o 2peak ). Improvements in endothelial function with exercise training are somewhat dependent on the intensity of exercise. While the acute stimulus for this improvement is not completely understood, it may, in part, be due to the flow-mediated dilation (FMD) response to acute exercise. We examined the hypothesis that exercise intensity alters the brachial (systemic) FMD response in elderly men and is modulated by V̇o 2peak Forty-seven elderly men were stratified into lower (V̇o 2peak = 24.3 ± 2.9 ml·kg -1 ·min -1 ; n = 27) and higher fit groups (V̇o 2peak = 35.4 ± 5.5 ml·kg -1 ·min -1 ; n = 20) after a test of cycling peak power output (PPO). In randomized order, participants undertook moderate-intensity continuous exercise (MICE; 40% PPO) or high-intensity interval cycling exercise (HIIE; 70% PPO) or no-exercise control. Brachial FMD was assessed at rest and 10 and 60 min after exercise. FMD increased after MICE in both groups {increase of 0.86% [95% confidence interval (CI), 0.17-1.56], P = 0.01} and normalized after 60 min. In the lower fit group, FMD was reduced after HIIE [reduction of 0.85% (95% CI, 0.12-1.58), P = 0.02] and remained decreased at 60 min. In the higher fit group, FMD was unchanged immediately after HIIE and increased after 60 min [increase of 1.52% (95% CI, 0.41-2.62), P < 0.01, which was correlated with V̇o 2peak , r = 0.41; P < 0.01]. In the no-exercise control, FMD was reduced in both groups after 60 min ( P = 0.05). Exercise intensity alters the acute FMD response in elderly men and V̇o 2peak modulates the FMD response following HIIE but not MICE. The sustained decrease in FMD in the lower fit group following HIIE may represent a signal for vascular adaptation or endothelial fatigue. NEW & NOTEWORTHY This study is the first to show that moderate-intensity continuous cycling exercise increased flow-mediated dilation (FMD) transiently before normalization of FMD after 1 h, irrespective of cardiorespiratory fitness level in elderly men. Interestingly, we show increased FMD after high-intensity cycling exercise in higher fit men, with a sustained reduction in FMD in lower fit men. The prolonged reduction in FMD after high-intensity cycling exercise may be associated with future vascular adaptation but may also reflect a period of increased cardiovascular risk in lower fit elderly men. Copyright © 2017 the American Physiological Society.

78 FR 70399 - Paperless Hazard Communications Pilot Program

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-25

..., and airplanes) and during inspection and emergency response simulations. (Note: For purposes of the pilot tests conducted under this project, ``simulation'' refers to planned exercises designed solely to... participants. The scope of the simulations will be defined by project data collection needs for testing...

12 CFR 150.150 - Who is responsible for the exercise of fiduciary powers?

Code of Federal Regulations, 2014 CFR

2014-01-01

... 12 Banks and Banking 1 2014-01-01 2014-01-01 false Who is responsible for the exercise of... and Facilities § 150.150 Who is responsible for the exercise of fiduciary powers? The exercise of your... responsibilities, the board may assign any function related to the exercise of fiduciary powers to any director...

12 CFR 150.150 - Who is responsible for the exercise of fiduciary powers?

Code of Federal Regulations, 2012 CFR

2012-01-01

... 12 Banks and Banking 1 2012-01-01 2012-01-01 false Who is responsible for the exercise of... and Facilities § 150.150 Who is responsible for the exercise of fiduciary powers? The exercise of your... responsibilities, the board may assign any function related to the exercise of fiduciary powers to any director...

12 CFR 550.150 - Who is responsible for the exercise of fiduciary powers?

Code of Federal Regulations, 2011 CFR

2011-01-01

... 12 Banks and Banking 5 2011-01-01 2011-01-01 false Who is responsible for the exercise of... Facilities § 550.150 Who is responsible for the exercise of fiduciary powers? The exercise of your fiduciary... responsibilities, the board may assign any function related to the exercise of fiduciary powers to any director...

12 CFR 550.150 - Who is responsible for the exercise of fiduciary powers?

Code of Federal Regulations, 2012 CFR

2012-01-01

... 12 Banks and Banking 6 2012-01-01 2012-01-01 false Who is responsible for the exercise of... Facilities § 550.150 Who is responsible for the exercise of fiduciary powers? The exercise of your fiduciary... responsibilities, the board may assign any function related to the exercise of fiduciary powers to any director...

12 CFR 150.150 - Who is responsible for the exercise of fiduciary powers?

Code of Federal Regulations, 2013 CFR

2013-01-01

... 12 Banks and Banking 1 2013-01-01 2013-01-01 false Who is responsible for the exercise of... and Facilities § 150.150 Who is responsible for the exercise of fiduciary powers? The exercise of your... responsibilities, the board may assign any function related to the exercise of fiduciary powers to any director...

Attenuation of Exaggerated Exercise Blood Pressure Response in African-American Women by Regular Aerobic Physical Activity

PubMed Central

Bond, Vernon; Millis, Richard M.; Adams, R. George; Oke, Luc M.; Enweze, Larry; Blakely, Raymond; Banks, Marshall; Thompson, Terry; Obisesan, Thomas; Sween, Jennifer C.

2011-01-01

Introduction A hyperreactive blood pressure response to exercise is a predictor of developing hypertension. The present study determined the influence of physical activity on an exaggerated exercise blood pressure response (EEBPR) in normotensive African-American women. Methods We screened 36 women 18–26 years of age for EEBPR defined as a ≥50 mm Hg difference in systolic blood pressure at rest and during exercise at 50% peak oxygen uptake (VO2peak). Seven subjects demonstrated an EEBPR and participated in the study. Study participants trained for eight weeks on a bicycle ergometer at a work intensity of 70% VO2peak. Blood pressure, heart rate, cardiac output (CO), stroke volume (SV), and total peripheral vascular resistance (TPR) were determined at baseline and during submaximal exercise at power outputs of 30 W and 50% VO2peak. Subjects served as their own controls, and data were evaluated by using a paired t test at P<.05. Results Effectiveness of the intervention was shown by a significantly greater VO2peak associated with significant decrements in systolic and mean arterial pressures at power outputs of 30 W and 50% VO2peak. A significant decrement in heart rate was observed during exercise at 30 W. Significant increments in CO and SV and decrement in TPR were found during exercise at 50% VO2peak. Conclusion The reduction in TPR associated with regular aerobic physical activity may attenuate the EEBPR and decrease the risk for hypertension in normotensive, young-adult, African-American women. PMID:16315376

Voluntary exercise increases resilience to social defeat stress in Syrian hamsters.

PubMed

Kingston, Rody C; Smith, Michael; Lacey, Tiara; Edwards, Malcolm; Best, Janae N; Markham, Chris M

2018-05-01

Exposure to social stressors can cause profound changes in an individual's well-being and can be an underlying factor in the etiology of a variety of psychopathologies, such as post-traumatic stress disorder (PTSD). In Syrian hamsters, a single social defeat experience results in behavioral changes collectively known as conditioned defeat (CD), and includes an abolishment of territorial aggression and the emergence of high levels of defensive behaviors. In contrast, voluntary exercise has been shown to promote stress resilience and can also have anxiolytic-like effects. Although several studies have investigated the resilience-inducing effects of voluntary exercise after exposure to physical stressors, such as restraint and electric shock, few studies have examined whether exercise can impart resilience in response to ethologically-based stressors, such as social defeat. In Experiment 1, we tested the hypothesis that voluntary exercise can have anxiolytic-like effects in socially defeated hamsters. In the elevated plus maze, the exercise group exhibited a significant reduction in risk assessment, a commonly used index of anxiety, compared to the no-exercise group. In the open-field test, animals in the exercise group exhibited a significant reduction in locomotor behavior and rearing, also an indication of an anxiolytic-like effect of exercise. In Experiment 2, we examined whether exercise can reverse the defeat-induced potentiation of defensive behaviors using the CD model. Socially defeated hamsters in the exercise group exhibited significantly lower levels of defensive/submissive behaviors compared to the no-exercise group upon exposure to the resident aggressor. Taken together, these results are among the first to suggest that voluntary exercise may promote resilience to social defeat stress in Syrian hamsters. Copyright © 2018 Elsevier Inc. All rights reserved.

Casein protein results in higher prandial and exercise induced whole body protein anabolism than whey protein in chronic obstructive pulmonary disease.

PubMed

Engelen, Mariëlle P K J; Rutten, Erica P A; De Castro, Carmen L N; Wouters, Emiel F M; Schols, Annemie M W J; Deutz, Nicolaas E P

2012-09-01

Exercise is known to improve physical functioning and health status in Chronic Obstructive Pulmonary Disease (COPD). Recently, disturbances in protein turnover and amino acid kinetics have been observed after exercise in COPD. The objective was to investigate which dairy protein is able to positively influence the protein metabolic response to exercise in COPD. 8 COPD patients and 8 healthy subjects performed a cycle test on two days while ingesting casein or whey protein. Whole body protein breakdown (WbPB), synthesis (WbPS), splanchnic amino acid extraction (SPE), and NetWbPS (=WbPS-WbPB) were measured using stable isotope methodology during 20 min of exercise (at 50% peak work load of COPD group). The controls performed a second exercise test at the same relative workload. Exercise was followed by 1 h of recovery. In the healthy group, WbPS, SPE, and NetPS were higher during casein than during whey feeding (P<.01). WbPS and NetPS were higher during exercise, independent of exercise intensity (P<.01). NetPS was higher during casein feeding in COPD due to lower WbPB (P<.05). Higher SPE was found during exercise during casein and whey feeding in COPD (P<.05). Lactate levels during exercise were higher in COPD (P<.05) independent of the protein. Post-exercise, lower NetPS values were found independent of protein type in both groups. Casein resulted in more protein anabolism than whey protein which was maintained during and following exercise in COPD. Optimizing protein intake might be of importance for muscle maintenance during daily physical activities in COPD. Copyright © 2012 Elsevier Inc. All rights reserved.

Plasma Irisin Modestly Increases during Moderate and High-Intensity Afternoon Exercise in Obese Females

PubMed Central

Winn, Nathan C.; Grunewald, Zachary I.; Liu, Ying; Heden, Timothy D.; Nyhoff, Lauren M.; Kanaley, Jill A.

2017-01-01

Background and Purpose Irisin is an exercise-responsive myokine that has been proposed to exert anti-obesity benefits; yet its response during exercise in obese women is not described. This study characterized plasma irisin levels during a single bout of afternoon isocaloric-exercise of different intensities (moderate- vs high-intensity) in obese females. Methods Eleven obese females participated in 3 randomized study days beginning at 1600h: 1) no exercise (NoEx), 2) moderate exercise (ModEx; 55%VO2max) and 3) high intensity interval exercise (IntEx; 4 min (80%VO2max)/3 min (50% VO2max). Frequent blood samples were analyzed for glucose and lactate (whole-blood), and insulin, c-peptide, glucagon, and irisin (plasma) throughout 190 min of testing. Results Plasma irisin increased above baseline during ModEx and IntEx (P<0.05), but not NoEx (P>0.05). Peak irisin levels during ModEx and IntEx exercise were 11.9± 3.4% and 12.3 ± 4.1% relative to baseline (P<0.05), respectively, with no differences between exercise intensities (P>0.05). Irisin levels remained elevated above resting for 125 minutes post-exercise during ModEx, whereas levels returned to baseline within 15 minutes post-exercise during IntEx. Similarly, no associations were found between plasma irisin levels and circulating lactate, glucose, insulin, c-peptide, or glucagon among study days (P>0.05). However, there was an inverse association between basal irisin and lean mass (r = -0.70, P = 0.01). Conclusion A single bout of moderate and high intensity afternoon exercise induces modest increases in circulating irisin concentrations during exercise; however the regulation post-exercise appears to be dimorphic between exercise intensity in obese females. Future studies are needed to compare morning and afternoon exercise on irisin secretion. PMID:28125733

Cardiorespiratory responses during underwater and land treadmill exercise in college athletes.

PubMed

Brubaker, Peter; Ozemek, Cemal; Gonzalez, Alimer; Wiley, Stephen; Collins, Gregory

2011-08-01

Underwater treadmill (UTM) exercise is being used with increased frequency for rehabilitation of injured athletes, yet there has been little research conducted on this modality. To determine the cardiorespiratory responses of UTM vs land treadmill (LTM) exercise, particularly with respect to the relationship between heart rate (HR) and oxygen consumption (VO2). This quantitative original research took place in sports medicine and athletic training facilities at Wake Forest University. 11 Wake Forest University student athletes (20.8 ± 0.6 y, 6 women and 5 men). All participants completed the UTM and LTM exercise-testing protocols in random order. After 5 min of standing rest, both UTM and LTM protocols had 4 stages of increasing belt speed (2.3, 4.9, 7.3, and 9.6 km/h) followed by 3 exercise stages at 9.6 km/h with increasing water-jet resistance (30%, 40%, and 50% of jet capacity) or inclines (1%, 2%, and 4% grade). A Cosmed K4b2 device with Polar monitor was used to collect HR, ventilation (Ve), tidal volume (TV), breathing frequency (Bf), and VO2 every minute. Ratings of perceived exertion (RPE) were also obtained each minute. There was no significant difference between UTM and LTM for VO2 at rest or during any stage of exercise except stage 3. Furthermore, there were no significant differences between UTM and LTM for HR, Ve, Bf, and RPE on any exercise stage. Linear regression of HR vs VO2, across all stages of exercise, indicates a similar relationship in these variables during UTM (r = .94, y = .269x - 10.86) and LTM (r = .95, y = .291x - 12.98). These data indicate that UTM and LTM exercise elicits similar cardiorespiratory responses and that HR can be used to guide appropriate exercise intensity for college athletes during UTM.

Effect of voluntary hypocapnic hyperventilation or moderate hypoxia on metabolic and heart rate responses during high-intensity intermittent exercise.

PubMed

Dobashi, Kohei; Fujii, Naoto; Watanabe, Kazuhito; Tsuji, Bun; Sasaki, Yosuke; Fujimoto, Tomomi; Tanigawa, Satoru; Nishiyasu, Takeshi

2017-08-01

To investigate the effect of voluntary hypocapnic hyperventilation or moderate hypoxia on metabolic and heart rate responses during high-intensity intermittent exercise. Ten males performed three 30-s bouts of high-intensity cycling [Ex1 and Ex2: constant-workload at 80% of the power output in the Wingate anaerobic test (WAnT), Ex3: WAnT] interspaced with 4-min recovery periods under normoxic (Control), hypocapnic or hypoxic (2500 m) conditions. Hypocapnia was developed through voluntary hyperventilation for 20 min prior to Ex1 and during each recovery period. End-tidal CO 2 pressure was lower before each exercise in the hypocapnia than control trials. Oxygen uptake ([Formula: see text]) was lower in the hypocapnia than control trials (822 ± 235 vs. 1645 ± 245 mL min -1 ; mean ± SD) during Ex1, but not Ex2 or Ex3, without a between-trial difference in the power output during the exercises. Heart rates (HRs) during Ex1 (127 ± 8 vs. 142 ± 10 beats min -1 ) and subsequent post-exercise recovery periods were lower in the hypocapnia than control trials, without differences during or after Ex2, except at 4 min into the second recovery period. [Formula: see text] did not differ between the control and hypoxia trials throughout. These results suggest that during three 30-s bouts of high-intensity intermittent cycling, (1) hypocapnia reduces the aerobic metabolic rate with a compensatory increase in the anaerobic metabolic rate during the first but not subsequent exercises; (2) HRs during the exercise and post-exercise recovery periods are lowered by hypocapnia, but this effect is diminished with repeated exercise bouts, and (3) moderate hypoxia (2500 m) does not affect the metabolic response during exercise.

NOS3 Glu298Asp genotype and blood pressure response to endurance training: the HERITAGE family study.

PubMed

Rankinen, T; Rice, T; Pérusse, L; Chagnon, Y C; Gagnon, J; Leon, A S; Skinner, J S; Wilmore, J H; Rao, D C; Bouchard, C

2000-11-01

Endothelium-dependent vasodilation is a mechanism that may affect blood pressure response to endurance training. Because NO plays a central role in this process, the endothelial NO synthase gene is a good candidate for the regulation of exercise blood pressure. We investigated the associations between an endothelial NO synthase gene polymorphism (Glu298Asp) and endurance training-induced changes in resting and submaximal exercise blood pressure in 471 white subjects of the HERITAGE Family Study. Two submaximal exercise tests at 50 W were conducted both before and after a 20-week endurance training program. Steady-state exercise blood pressure was measured twice in each test with an automated unit. The Glu298Asp polymorphism was typed with a PCR-based method and digestion with BAN:II. Both systolic and diastolic blood pressure at 50 W decreased in response to the training program, whereas resting blood pressure remained unchanged. The decrease in diastolic blood pressure at 50 W was greater (P=0.0005, adjusted for age, gender, baseline body mass index, and baseline diastolic blood pressure at 50 W) in the Glu/Glu homozygotes (4.4 [SEM 0.4] mm Hg, n=187) than in the heterozygotes (3.1 [0.4] mm Hg, n=213) and the Asp/Asp homozygotes (1.3 [0.7] mm Hg, n=71). The genotype accounted for 2.3% of the variance in diastolic blood pressure at 50 W training response. Both the Glu298 homozygotes and the heterozygotes had a greater (P=0.013) training-induced reduction in rate-pressure product at 50 W than the Asp298 homozygotes. These data suggest that DNA sequence variation in the endothelial NO synthase gene locus is associated with the endurance training-induced decreases in submaximal exercise diastolic blood pressure and rate-pressure product in sedentary normotensive white subjects.

Influence of inspired oxygen concentration on the dynamics of the exercise hyperpnoea in man.

PubMed Central

Griffiths, T L; Henson, L C; Whipp, B J

1986-01-01

In order to determine the role of the carotid bodies on the ventilatory control characteristics during the non-steady-state phase of exercise in man, six normal males performed cycle ergometry with four repetitions of a 6 min, constant-load work bout at inspired O2 fractions (FI,O2) of 0.12, 0.15, 0.21, 0.30 and 1.00. Each test began with unloaded pedalling; this was followed by a constant load which was 90% of the subject's anaerobic threshold at FI,O2 = 0.12. Ventilation (VE), CO2 output (VCO2) and O2 uptake (VO2) were determined breath-by-breath during the test and the time constants of response (tau VE, tau VCO2 and tau VO2) were established by least-squares techniques, following interpolation (1 s), temporal alignment and averaging of the four responses. In each subject, tau VE and tau VCO2 increased as functions of increasing FI,O2, and were inverse functions of the proportional contribution to VE of peripheral chemoreceptor drive (as estimated from hyperoxic-transition or 'Dejours' tests). tau VE averaged 40 s at FI,O2 = 0.12 and 112 s at FI,O2 = 1.00, each response being well fitted by a single exponential. However, tau VO2 was not significantly affected by the alterations in FI,O2. Although there was no discernible peripheral chemosensitivity at FI,O2 = 0.30 or 1.00, the tau VE increased appreciably between these inspirates. We therefore conclude that the peripheral chemoreceptors are important, but not exclusive determinants of the exponential response characteristics during the non-steady-state phase of the exercise hyperpnoea in man. This supports the contention of a component of the control being humorally mediated even during moderate exercise. PMID:3612567

Oxygen uptake kinetics of constant-load work - Upright vs. supine exercise

NASA Technical Reports Server (NTRS)

Convertino, V. A.; Goldwater, D. J.; Sandler, H.

1984-01-01

Supine and upright positions were used in a comparitive study of the effects of constant load exercise on oxygen uptake (VO2), O2 deficit, steady-state VO2 and VO2 following recovery from constant load work. Ten male subjects (36-40 yr.) performed one submaximal exercise test in the supine and one test in the upright position consisting of 5 min rest and 5 min cycle ergometer exercise at 700 kg/min followed by ten minutes of recovery. It is found that the significant difference in VO2 kinetics during exercise in the upright compared to supine position resulted from changes in oxygen transport and utilization mechanisms rather than changes in mechanical efficiency. To the extent that data measured in the supine position can be used to estimate physiological responses to zero gravity, it is suggested that limitation of systemic O2 consumption may be the result of slow rates of oxygen uptake during transient periods of muscular work. Significant reductions in the rate of steady-state VO2 attainment at submaximal work intensities may produce an onset of muscle fatigue and exhaustion.

The Gravity-Loading countermeasure Skinsuit (GLCS) and its effect upon aerobic exercise performance

NASA Astrophysics Data System (ADS)

Attias, Julia; Philip, A. T. Carvil; Waldie, James; Russomano, Thais; Simon, N. Evetts; David, A. Green

2017-03-01

The Russian Pingvin suit is employed as a countermeasure to musculoskeletal atrophy in microgravity, though its 2-stage loading regime is poorly tolerated. The Gravity-Loading Countermeasure Skinsuit (GLCS) has been devised to comfortably compress the body via incrementally increasing longitudinal elastic-fibre tensions from the shoulders to the feet. We tested whether the Mk III GLCS was a feasible adjunct to sub-maximal aerobic exercise and resulting VO2Max predictions. Eight healthy subjects (5♂, 28±6 yr) performed cycle ergometry at 75% VO2Max (derived from an Astrand-Rhyming protocol) whilst wearing a GLCS and gym clothing (GYM). Ventilatory parameters, heart rate (HR), core temperature (TC), and blood lactate (BL) were recorded along with subjective perceived exertion, thermal comfort, movement discomfort and body control. Physiological and subjective responses were compared over TIME and between GYM and GLCS (ATTIRE) with 2-way repeated measures ANOVA and Wilcoxon tests respectively. Resultant VO2Max predictions were compared with paired t-tests between ATTIRE. The GLCS induced greater initial exercise ventilatory responses which stabilised by 20 min. HR and TC continued to rise from 5 min irrespective of ATTIRE, whereas BL was greater in the GLCS at 20 min. Predicted V O2Max did not differ with ATTIRE, though some observed differences in HR were noteworthy. All subjective ratings were exacerbated in the GLCS. Despite increased perception of workload and initial ventilatory augmentations, submaximal exercise performance was not impeded. Whilst predicted VO2Max did not differ, determination of actual VO2Max in the GLCS is warranted due to apparent modulation of the linear HR-VO2 relationship. The GLCS may be a feasible adjunct to exercise and potential countermeasure to unloaded-induced physiological deconditioning on Earth or in space.

Influence of Exercise Intensity for Improving Depressed Mood in Depression: A Dose-Response Study.

PubMed

Meyer, Jacob D; Koltyn, Kelli F; Stegner, Aaron J; Kim, Jee-Seon; Cook, Dane B

2016-07-01

Exercise effectively improves mood in major depressive disorder (MDD), but the optimal exercise stimulus to improve depressed mood is unknown. To determine the dose-response relationship of acute exercise intensity with depressed mood responses to exercise in MDD. We hypothesized that the acute response to exercise would differ between light, moderate, and hard intensity exercise with higher intensities yielding more beneficial responses. Once weekly, 24 women (age: 38.6±14.0) diagnosed with MDD underwent a 30-minute session at one of three steady-state exercise intensities (light, moderate, hard; rating of perceived exertion 11, 13 or 15) or quiet rest on a stationary bicycle. Depressed mood was evaluated with the Profile of Mood States before, 10 and 30 minutes post-exercise. Exercise reduced depressed mood 10 and 30 minutes following exercise, but this effect was not influenced by exercise intensity. Participants not currently taking antidepressants (n=10) had higher baseline depression scores, but did not demonstrate a different antidepressant response to exercise compared to those taking antidepressants. To acutely improve depressed mood, exercise of any intensity significantly improved feelings of depression with no differential effect following light, moderate, or hard exercise. Pharmacological antidepressant usage did not limit the mood-enhancing effect of acute exercise. Acute exercise should be used as a symptom management tool to improve mood in depression, with even light exercise an effective recommendation. These results need to be replicated and extended to other components of exercise prescription (e.g., duration, frequency, mode) to optimize exercise guidelines for improving depression. Copyright © 2016. Published by Elsevier Ltd.

Corticomotor excitability during a noxious stimulus before and after exercise in women with fibromyalgia.

PubMed

Hoeger Bement, Marie K; Weyer, Andy D; Yoon, Tejin; Hunter, Sandra K

2014-02-01

The purposes of this study were to assess corticomotor excitability in people with fibromyalgia during a noxious stimulus before and after fatiguing exercise and examine associations with pain perception. Fifteen women with fibromyalgia completed three sessions: one familiarization and two experimental. The experimental sessions were randomized and involved measurement of pain perception and motor evoked potentials before and after (1) quiet rest and (2) isometric contraction of the elbow flexor muscles. Motor evoked potential amplitude of brachioradialis muscle was measured following transcranial magnetic stimulation delivered before, during, and after a noxious mechanical stimulus. After quiet rest, there was no change in pain perception. After the submaximal contraction, there was considerable variability in the pain response. Based on the changes in the experimental pain, subjects were divided into three groups (increase, decrease, and no change in pain). There was an interaction between pain response and the pain-induced change in motor evoked potentials. Those individuals who had an increase in motor evoked potentials during the pain test had an increase in pain after exercise. Thus, women with fibromyalgia were classified based on their pain response to exercise, and this response was associated with the change in corticomotor excitability during the application of a noxious stimulus.

Elevated extracellular potassium prior to muscle contraction reduces onset and steady-state exercise hyperemia in humans.

PubMed

Terwoord, Janée D; Hearon, Christopher M; Luckasen, Gary J; Richards, Jennifer C; Joyner, Michael J; Dinenno, Frank A

2018-05-03

The increase in interstitial potassium (K + ) during muscle contractions is thought to be a vasodilatory signal that contributes to exercise hyperemia. To determine the role of extracellular K + in exercise hyperemia, we perfused skeletal muscle with K + prior to contractions such that the effect of any endogenously-released K + would be minimized. We tested the hypothesis that local, intra-arterial infusion of potassium chloride (KCl) at rest would impair vasodilation in response to subsequent rhythmic handgrip exercise in humans. In 11 young adults, we determined forearm blood flow (FBF; Doppler ultrasound) and vascular conductance (FVC; FBF/mean arterial pressure) during 4 minutes of rhythmic handgrip exercise at 10% of maximal voluntary contraction during 1) control conditions (CTRL), 2) infusion of KCl prior to the initiation of exercise, and 3) infusion of sodium nitroprusside (SNP) as a control vasodilator. Infusion of KCl or SNP elevated resting FVC similarly prior to the onset of exercise (CTRL: 39 {plus minus} 6 vs. KCl: 81 {plus minus} 12 and SNP: 82 {plus minus} 13 ml/min/100 mmHg; both P < 0.05 vs. CTRL). Infusion of KCl at rest diminished the hyperemic (Δ FBF) and vasodilatory (Δ FVC) response to subsequent exercise by 22 {plus minus} 5% and 30 {plus minus} 5%, respectively (both P < 0.05 vs. CTRL), whereas SNP did not affect the change in FBF (P = 0.74 vs. CTRL) or FVC (P = 0.61 vs. CTRL) from rest to steady-state exercise. These findings implicate the K + ion as an essential vasodilator substance contributing to exercise hyperemia in humans.

Acute exercise attenuates negative affect following repeated sad mood inductions in persons who have recovered from depression.

PubMed

Mata, Jutta; Hogan, Candice L; Joormann, Jutta; Waugh, Christian E; Gotlib, Ian H

2013-02-01

Identifying factors that may protect individuals from developing Major Depressive Disorder (MDD) in the face of stress is critical. In the current study we experimentally tested whether such a potentially protective factor, engaging in acute exercise, reduces the adverse effects of repeated sad mood inductions in individuals who have recovered from depression. We hypothesized that recovered depressed participants who engage in acute exercise report a smaller increase in negative affect (NA) and a smaller decrease in positive affect (PA) when exposed to a repeated sad mood induction (i.e., habituation), whereas participants who do not exercise show sensitization (i.e., increased NA and decreased PA in response to a repeated adverse stimulus). Forty-one women recovered from MDD and 40 healthy control women were randomly assigned to either exercise for 15 minutes or quiet rest. Afterward, participants were exposed to two sad mood inductions and reported their levels of affect throughout the study. Recovered depressed participants who had not exercised exhibited higher NA after the second sad mood induction, a finding consistent with sensitization. In contrast, both recovered depressed participants who had engaged in acute exercise and healthy control participants showed no increase in NA in response to the repeated sad mood induction. Participants who exercised reported higher PA after the exercise bout; however, our hypothesis concerning reported PA trajectories following the sad mood inductions was not supported. Results suggest that exercise can serve as a protective factor in the face of exposure to repeated emotional stressors, particularly concerning NA in individuals who have recovered from depression. 2013 APA, all rights reserved

Comparison of arterial potassium and ventilatory dynamics during sinusoidal work rate variation in man.

PubMed Central

Casaburi, R; Stringer, W W; Singer, E

1995-01-01

1. The mechanisms underlying the exercise hyperpnoea have been difficult to define. Recently it has been suggested that exercise ventilation (VE) changes in proportion to changes in arterial potassium concentration ([K+]a). Similar VE and [K+]a time courses following work rate changes have been cited as supporting evidence. This study compared [K+]a and VE dynamics during moderate exercise in man. 2. We observed VE and gas exchange responses in five healthy men to sinusoidal work rate variation between 25 and approximately 105 W. Tests of approximately 30 min duration were performed at sinusoidal periods of 9, 6 and 3 min and in the steady state. In each test, during two or three sine periods, arterial blood was sampled (24 per test) and analysed for [K+] and blood gases. Response amplitude and phase (relative to work rate) were determined for each variable. 3. [K+]a fluctuated in response to sinusoidal work rate forcing with mean-to-peak amplitude averaging 0.15 mmol 1(-1). However, among tests, VE amplitude and phase were not highly correlated with [K+]a (r = 0.36 and 0.67, respectively). Further, average [K+]a amplitude in the 9 and 6 min sinusoidal studies tended to exceed the steady-state amplitude, while average VE amplitude fell progressively with increasing forcing frequency. The dissimilar dynamics of [K+]a and VE seem inconsistent with a major role for [K+]a as a proportional controller of ventilation during non-steady state moderate exercise in man. 4. Among tests, VE and CO2 output (VCO2) amplitude and phase were closely correlated (r = 0.87 and 0.94, respectively). Further, arterial CO2 pressure (Pa,CO2) and arterial pH(pHa) did not fluctuate significantly in ten of twenty and thirteen of twenty studies, respectively. In tests where sinusoidal fluctuation was detected, amplitude averaged 1.1 mmHg and 0.008 units, respectively. Thus VE demonstrated a close dynamic coupling to CO2 output, with consequent tight regulation of Pa,CO2 and pHa. PMID:7666376

The Effect of Omega-3 Fatty Acid Supplementation on the Inflammatory Response to eccentric strength exercise.

PubMed

Jouris, Kelly B; McDaniel, Jennifer L; Weiss, Edward P

2011-01-01

Omega-3 fatty acids (omega-3) have anti-inflammatory properties. However, it is not known if omega-3 supplementation attenuates exercise-induced inflammation. We tested the hypothesis that omega-3 supplementation reduces inflammation that is induced by eccentric arm curl exercise. Healthy adult men and women (n=11; 35 ± 10 y) performed eccentric biceps curls on two occasions, once after 14d of dietary omega-3 restriction (control trial) and again after 7d of 3,000 mg/d omega-3 supplementation (omega-3 trial). Before and 48 h after eccentric exercise, signs of inflammation was assessed by measuring soreness ratings, swelling (arm circumference and arm volume), and temperature (infrared skin sensor). Arm soreness increased (p < 0.0001) in response to eccentric exercise; the magnitude of increase in soreness was 15% less in the omega-3 trial (p = 0.004). Arm circumference increased after eccentric exercise in the control trial (p = 0.01) but not in the omega-3 trial (p = 0.15). However, there was no difference between trials (p = 0.45). Arm volume and skin temperature did not change in response to eccentric exercise in either trial. These findings suggest that omega-3 supplementation decreases soreness, as a marker of inflammation, after eccentric exercise. Based on these findings, omega-3 supplementation could provide benefits by minimizing post-exercise soreness and thereby facilitate exercise training in individuals ranging from athletes undergoing heavy conditioning to sedentary subjects or patients who are starting exercise programs or medical treatments such as physical therapy or cardiac rehabilitation. Key pointsDietary supplementation with omega-3 fatty acids has been shown to reduce inflammation in numerous inflammatory diseases such as rheumatoid arthritis, inflammatory bowel disease, and Chrohn's disease.Although strenuous exercise is known to cause acute increases in inflammation, it is not clear if omega-3 fatty acid supplementation attenuates this adverse response to exercise.Our research demonstrates that 3000 mg·d-1 omega-3 fatty acid supplementation minimizes the severe, delayed-onset muscle soreness that results from strenuous eccentric strength exercise.This information, along with a plethora of information showing that omega-3 fatty acid supplementation has other health benefits, demonstrates that a readily available over the counter nutritional supplement (i.e. omega-3 fatty acids) reduces delayed-onset soreness caused by strenuous strength exercise.This information has obvious relevance to athletic populations but also to other groups such as physical therapy patients and newly admitted cardiac rehabilitation patients, as muscle soreness, if left unchecked, can slow the progress in adapting to a new exercise program.Furthermore, as inflammation is known to be involved in the pathogenesis if numerous diseases, including heart disease, cancer, and diabetes, it is likely prudent for individuals to use inflammation-attenuating interventions, such as omega-3 supplementation, to keep inflammatory responses to physical activity at a minimum.

Disease resistance is related to inherent swimming performance in Atlantic salmon

PubMed Central

2013-01-01

Background Like humans, fish can be classified according to their athletic performance. Sustained exercise training of fish can improve growth and physical capacity, and recent results have documented improved disease resistance in exercised Atlantic salmon. In this study we investigated the effects of inherent swimming performance and exercise training on disease resistance in Atlantic salmon. Atlantic salmon were first classified as either poor or good according to their swimming performance in a screening test and then exercise trained for 10 weeks using one of two constant-velocity or two interval-velocity training regimes for comparison against control trained fish (low speed continuously). Disease resistance was assessed by a viral disease challenge test (infectious pancreatic necrosis) and gene expression analyses of the host response in selected organs. Results An inherently good swimming performance was associated with improved disease resistance, as good swimmers showed significantly better survival compared to poor swimmers in the viral challenge test. Differences in mortalities between poor and good swimmers were correlated with cardiac mRNA expression of virus responsive genes reflecting the infection status. Although not significant, fish trained at constant-velocity showed a trend towards higher survival than fish trained at either short or long intervals. Finally, only constant training at high intensity had a significant positive effect on fish growth compared to control trained fish. Conclusions This is the first evidence suggesting that inherent swimming performance is associated with disease resistance in fish. PMID:23336751

Responsiveness to montelukast is associated with bronchial hyperresponsiveness and total immunoglobulin E but not polymorphisms in the leukotriene C4 synthase and cysteinyl leukotriene receptor 1 genes in Korean children with exercise-induced asthma (EIA).

PubMed

Lee, S-Y; Kim, H-B; Kim, J-H; Kim, B-S; Kang, M-J; Jang, S-O; Seo, H-J; Hong, S-J

2007-10-01

As previous studies have shown that cysteinyl leukotrienes are important mediators in exercise-induced bronchoconstriction (EIB), and leukotriene receptor antagonists (LTRAs) such as montelukast have been shown to improve post-exercise bronchoconstrictor responses, we herein investigated whether clinical responsiveness to montelukast was associated with polymorphisms in the genes encoding leukotriene C4 synthase (LTC4S) and cysteinyl leukotriene receptor 1 (CysLTR1) and/or clinical parameters in Korean asthmatic children with EIB. The study population consisted of 100 asthmatic children with EIB. The individuals studied were given exercise challenge tests before and after receiving montelukast (5 mg/day) for 8 weeks. Responders were defined as children showing>10% post-treatment improvement in forced expiratory volume in 1 s (FEV1). The LTC4S A(-444)C and CysLTR1 T(+927)C polymorphisms were genotyped by PCR-restriction fragment length polymorphism analysis. Of 100 enrolled children, 68 were classified as responders and 32 were classified as non-responders. No significant association was observed between montelukast responsiveness and LTC4S or CysLTR1 genotype, either alone or in combination. In contrast, montelukast-induced improvement in FEV(1) after exercise was correlated with higher pre-treatment PC20 (methacholine) values (r=0.210, P=0.036) and lower total IgE levels (r=-0.216, P=0.031). The LTC4S A(-444)C and CysLTR1 T(+927)C genotypes do not appear to be useful for predicting clinical responsiveness to montelukast, whereas bronchial hyperresponsiveness and total IgE appear to predict the degree of montelukast responsiveness in Korean asthmatic children with EIB.

Temporal characteristics of exercise-induced diaphragmatic fatigue.

PubMed

Archiza, Bruno; Welch, Joseph F; Geary, Caitlin M; Allen, Grayson P; Borghi-Silva, Audrey; Sheel, A William

2018-04-01

There is evidence suggesting diaphragmatic fatigue (DF) occurs relatively early during high-intensity exercise; however, studies investigating the temporal characteristics of exercise-induced DF are limited by incongruent methodology. Eight healthy adult males (25 ± 5 yr) performed a maximal incremental exercise test on a cycle ergometer on day 1. A constant-load time-to-exhaustion (TTE) exercise test was conducted on day 2 at 60% delta between the calculated gas exchange threshold and peak work rate. Two additional constant-load exercise tests were performed at the same intensity on days 3 and 4 in a random order to either 50 or 75% TTE. DF was assessed on days 2, 3, and 4 by measuring transdiaphragmatic twitch pressure (P di,tw ) in response to cervical magnetic stimulation. DF was present after 75 and 100% TTE (≥20% decrease in P di,tw ). The magnitude of fatigue was 15.5 ± 5.7%, 23.6 ± 6.4%, and 35.0 ± 12.1% at 50, 75, and 100% TTE, respectively. Significant differences were found between 100 to 75 and 50% TTE (both P < 0.01), and 75 to 50% TTE ( P < 0.01). There was a significant relationship between the magnitude of fatigue and cumulative diaphragm force output ( r = 0.785; P < 0.001). Ventilation, the mechanical work of breathing (WOB), and pressure-time products were not different between trials ( P > 0.05). Our data indicate that exercise-induced DF presents a relatively late onset and is proportional to the cumulative WOB; thus the ability of the diaphragm to generate pressure progressively declines throughout exercise. NEW & NOTEWORTHY The notion that diaphragmatic fatigue (DF) occurs relatively early during exercise is equivocal. Our results indicate that DF occurs during high-intensity endurance exercise in healthy men and its magnitude is strongly related to the amount of pressure and work generated by respiratory muscles. Thus we conclude that the work of breathing is the major determinant of exercise-induced DF.

Upright exercise or supine lower body negative pressure exercise maintains exercise responses after bed rest

NASA Technical Reports Server (NTRS)

Lee, S. M.; Bennett, B. S.; Hargens, A. R.; Watenpaugh, D. E.; Ballard, R. E.; Murthy, G.; Ford, S. R.; Fortney, S. M.

1997-01-01

Adaptation to bed rest or space flight is accompanied by an impaired ability to exercise in an upright position. We hypothesized that a daily, 30-min bout of intense, interval exercise in upright posture or supine against lower body negative pressure (LBNP) would maintain upright exercise heart rate and respiratory responses after bed rest. Twenty-four men (31 +/- 3 yr) underwent 5 d of 6 degree head-down tilt: eight performed no exercise (CON), eight performed upright treadmill exercise (UPex), and eight performed supine treadmill exercise against LBNP at -51.3 +/- 0.4 mm Hg (LBNPex). Submaximal treadmill exercise responses (56, 74, and 85% of VO2peak) were measured pre- and post-bed rest. In CON, submaximal heart rate, respiratory exchange ratio, and ventilation were significantly greater (P < or = 0.05) after bed rest. In UPex and LBNPex, submaximal exercise responses were similar pre- and post-bed rest. Our results indicate that a daily 30-min bout of intense, interval upright exercise training or supine exercise training against LBNP is sufficient to maintain upright exercise responses after 5 d of bed rest. These results may have important implications for the development of exercise countermeasures during space flight.

Concentric and eccentric exercise, glycemic responses to a postexercise meal, and inflammation in women with high versus low waist circumference.

PubMed

Miles, Mary P; Horrigan, Laura C; Jay, Sara E; Brown, Karen M; Porter, Jay W; Steward, Andrea N

2016-12-01

Carbohydrate ingestion and level of concentric versus eccentric muscle activity may alter exercise-induced health benefits for individuals who have high waist circumference as a metabolic risk factor. The purpose of this study was to determine whether metabolic and inflammation responses to an exercise recovery meal differ between women with lower (Lo-WC, <80 cm) compared with higher (Hi-WC) waist circumference when the exercise is primarily concentric (uphill walking; UPHILL) versus primarily eccentric (downhill walking; DOWNHILL). Recreationally active women (age, 18-39 years; body mass index, 19-35.4 m·kg -2 ; Lo-WC, n = 13; Hi-WC, n = 10) completed UPHILL, DOWNHILL, and resting (CONTROL) conditions followed 30 min later by a mixed meal tolerance test (MMTT) with carbohydrates to protein ratio of 4:1, and blood glucose, insulin, and inflammation markers were compared across conditions. Compared with Lo-WC, the Hi-WC group had higher (p < 0.05) (i) insulin during the MMTT in CONTROL (mean ± SE; 48.5 ± 8.2 vs 22.9 ± 2.8 pmol·L -1 ), (ii) baseline (0.7 ± 0.4 vs 2.0 ± 1.7 pg·mL -1 ) interleukin-6 (IL-6), and (iii) IL-6 responses 8 h after UPHILL and CONTROL. Both groups had (i) increases in IL-6 at 0 h after UPHILL and at 8 h after DOWNHILL, and (ii) lower glycemic responses in UPHILL. Women with Hi-WC had higher IL-6 at rest and delayed increases in IL-6 after a high-carbohydrate meal in all conditions. This is consistent with an inflammation response to the meal and or uphill walking exercise. However, both concentrically and eccentrically biased exercises offered benefits to insulin responses to a high carbohydrate meal for Hi-WC.

12 CFR 550.150 - Who is responsible for the exercise of fiduciary powers?

Code of Federal Regulations, 2014 CFR

2014-01-01

... 12 Banks and Banking 6 2014-01-01 2012-01-01 true Who is responsible for the exercise of fiduciary... Facilities § 550.150 Who is responsible for the exercise of fiduciary powers? The exercise of your fiduciary... responsibilities, the board may assign any function related to the exercise of fiduciary powers to any director...