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

Exercise is impaired in hot, compared to moderate, conditions. The development of hyperthermia is strongly linked to the impairment and as a result, many different strategies have been investigated to combat this. This meta-analysis focused on one of the most popular strategies: cooling. Pre-cooling has received the most attention but more recently cooling applied during the bout of exercise has also been investigated and both were reviewed. We conducted a literature search and retrieved twenty-eight articles which investigated the effect of cooling administered either prior to (n=23) or during (n=5) an exercise test in hot (WBGT >26°C) conditions. Mean and weighted effect sizes (Cohen’s d) were calculated. Overall, pre-cooling has a moderate (d=0.73) effect on subsequent performance but the magnitude of the effect is dependent upon the nature of the test. Sprint performance is impaired (d=-0.26) but intermittent performance and prolonged exercise are both improved following cooling (d=0.47 and d=1.91 respectively). Cooling during exercise also has a positive effect on performance and capacity (d=0.76). Improvements were observed in studies with and without cooling-induced physiological alterations and the literature supports the suggestion of a dose-response relationship between cooling, thermal strain and improvements in performance and capacity. In summary, pre-cooling can improve subsequent intermittent and prolonged exercise performance and capacity in a hot environment but sprint performance is impaired. Cooling during exercise also has a positive effect on exercise performance and capacity in a hot environment

From catastrophe to complexity: a novel model of integrative central neural regulation of effort and fatigue during exercise in humans

It is a popular belief that exercise performance is limited by metabolic changes in the exercising muscles, so called peripheral fatigue. Exercise terminates when there is a catastrophic failure of homoeostasis in the exercising muscles. A revolutionary theory is presented that proposes that exercise performance is regulated by the central nervous system specifically to ensure that catastrophic physiological failure does not occur during normal exercise in humans

The Effect of UNH Undergraduate Student Exercise on Academic Achievement

A number of existing studies focus on the effect exercise and dietary habits have on social relationships; however, few studies examine the relationship between exercise and academic performance on college students. In this study, surveys were administered to 202 students at the University of New Hampshire. Although the data presented no statistically significant findings to prove a correlation between exercise and academic performance, students who never exercised were shown to be more likely to do poorly rather than excel academically. Future research should consist of a larger sample using a random sampling method for better reliability and validity in determining a relationship between student exercise and academic performance

The effects of sago supplementation for exercise in a warm-humid environment : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Health (Sport & Exercise) at Massey University, Manawatu, New Zealand

Content from Appendix B removed due to copyright restriction: Che Jusoh, M. R., Morton, R. H., Stannard, S. R., & Mündel, T. (2015). A reliable preloaded cycling time trial for use in conditions of significant thermal stress. Scandinavian Journal of Medicine & Science in Sports, 25(S1), 296Whilst carbohydrate (CHO) ingestion during exercise with heat stress theoretically has some benefits for performance there is a lack of evidence on the effects of complex-CHO on exercise and recovery in warm-humid (tropical) conditions. The aims of this thesis were to investigate the effects of sago feeding on exercise performance, some physiological parameters, substrate metabolism, and thermoregulatory responses in the condition of exercise with thermal stress. The initial experimental study investigated the reliability of two novel laboratory-based cycling protocols in the presence of significant thermal stress. These protocols would then be employed in the second part of this thesis. The data indicate that the 15 min time-trial pre-loaded with 45 min fixed-intensity (Chapter 5, Study A) and 15 min time-trial pre-loaded with 15 min incremental warm-up (Chapter 5, Study B) were highly reliable when using trained, familiarized males under warm-humid environmental conditions. The second part of this thesis describes experiments which investigated the efficacy of an alternative Malaysian-based CHO, sago, on exercise in conditions which replicate the Malaysian environment (warm and humid). Chapter 6 describes a study investigating the effect of sago supplementation before and during exercise in a warm-humid environment. The data collected from this study revealed that pre- and during-sago feeding has no differential effects on exercise performance though sago feeding produced a higher glycaemic response during the hour prior to exercise. However, feeding sago before exercise attenuated the rise in core temperature during exercise compared to the control condition, whilst there was a smaller reduction in plasma volume found when consuming sago during steady-state exercise through reduced whole-body sweating, with a concomitant higher plasma sodium concentration. Heart rate was also higher when sago was ingested either before or during exercise compared to control. Then, Chapter 7 further investigated the utility of sago ingestion as a recovery meal on a subsequent exercise bout in a warm-humid environment. In terms of performance, sago ingestion during short-term recovery seemed to sustain time-trial performance on the second bout of exercise compared to a control condition (no food) where exercise performance degraded. However, no attenuation of physiological, metabolic and thermoregulatory responses was apparent. C

Test-Retest Reliability and Validity of the Plank Exercise

Purpose: The plank exercise is a popular and widely used exercise to increase core strength. We previously established normative values for the plank exercise that may be used for fitness classification to identify gaps in core muscular strength and endurance. Whether the plank exercise can be confidently added to current fitness appraisal protocols will depend on its reliability and validity in the fitness testing environment. This study sought to examine test-retest reliability of the plank exercise and to compare plank performance with established normative values for the curl up test. The role of verbal encouragement cues during plank performance testing was also assessed. Methods: Collegiate male (n=14) and female participants (n=19) performed the plank exercise in two separate sessions separated by a minimum of 72 hr. Participants maintained the plank position until complete fatigue was reached. Verbal cues were given to half of the participants in one of the two sessions. Performance on the curl up exercise was measured in a third, separate session. Results: Intraclass correlation showed that mean time held in the plank position was not significantly different between the two plank testing sessions (108.15 + 49.38 versus 111.39 + 56.87 seconds, p=0.556). Verbal encouragement cues did not improve performance time (between group effect, p=0.940). The curl up test was not significantly correlated with either plank session (r=0.410 and 0.276 for plank session one and two, respectively). Surprisingly, the curl up test was positively correlated with participant height (r=0.578). Conclusion: This study suggests that the plank exercise is a reliable test; plank performance was comparable across testing sessions and not influenced by verbal encouragement. Further testing is needed to confirm validity of the plank exercise as a measure of core muscular endurance. We show here that plank performance was not correlated with the standard curl up test. However, the curl up test may not adequately measure core strength, given that increased body height was associated with higher curl up completion scores

Carbohydrate supplementation and prolonged intermittent, high-intensity exercise in adolescents: research findings, ethical issues and suggestions for the future

In the last decade, research has begun to investigate the efficacy of carbohydrate supplementation for improving aspects of physical capacity and skill performance during sport-specific exercise in adolescent team games players. This research remains in its infancy, and further study would be beneficial considering the large youth population actively involved in team games. Literature on the influence of carbohydrate supplementation on skill performance is scarce, limited to shooting accuracy in adolescent basketball players and conflicting in its findings. Between-study differences in the exercise protocol, volume of fluid and carbohydrate consumed, use of prior fatiguing exercise and timing of skill tests may contribute to the different findings. Conversely, initial data supports carbohydrate supplementation in solution and gel form for improving intermittent endurance running capacity following soccer-specific shuttle running. These studies produced reliable data, but were subject to limitations including lack of quantification of the metabolic response of participants, limited generalization of data due to narrow participant age and maturation ranges, use of males and females within the same sample and non-standardized pre-exercise nutritional status between participants. There is a lack of consensus regarding the influence of frequently consuming carbohydrate-containing products on tooth enamel erosion and the development of obesity or being overweight in adolescent athletes and non-athletes. These discrepancies mean that the initiation or exacerbation of health issues due to frequent consumption of carbohydrate-containing products by adolescents cannot be conclusively refuted. Coupled with the knowledge that consuming a natural, high-carbohydrate diet ∼3–8 hours before exercise can significantly alter substrate use and improve exercise performance in adults, a moral and ethical concern is raised regarding the direction of future research in order to further knowledge while safeguarding the health and well-being of young participants. It could be deemed unethical to continue study into carbohydrate supplementation while ignoring the potential health concerns and the possibility of generating similar performance enhancements using natural dietary interventions. Therefore, future work should investigate the influence of pre-exercise dietary intake on the prolonged intermittent, high-intensity exercise performance of adolescents. This would enable quantification of whether pre-exercise nutrition can modulate exercise performance and, if so, the optimum dietary composition to achieve this. Research could then combine this knowledge with ingestion of carbohydrate-containing products during exercise to facilitate ethical and healthy nutritional guidelines for enhancing the exercise performance of adolescents. This article addresses the available evidence regarding carbohydrate supplementation and prolonged intermittent, high-intensity exercise in adolescent team games players. It discusses the potential health concerns associated with the frequent use of carbohydrate-containing products by adolescents and how this affects the research ethics of the field, and considers directions for future work

Effect of inspiratory pressure support on exercise performance in patients with chronic obstructive pulmonary disease

Title: Effect of inspiratory pressure support on exercise performance in patients with chronic obstructive pulmonary disease. Purpose: This study examined the effects of a non-invasive ventilator on submaximal and maximal exercise performance in patients with chronic obstructive pulmonary disease (COPD). Methods: Fourteen men (66.0 ± 7.4yr) and six women (59.0 ± 7.4yr) with a diagnosis of COPD, a forced expiratory volume! (FEVi) <40%, and the ability to tolerate 12 cmH20 of pressure on a non- invasive ventilator performed two maximal exercise tests on a cycle ergometer, with and without ventilatory assistance prior to exercise. Blood samples, respiratory metabolic measures, heart rate and rating of perceived exertion (RPE) were obtained throughout each exercise test. Results: Peak work rate (W), total exercise time, and respiratory rate were higher (p<0.05) when exercise was preceded by ventilatory support compared to no support. There was no difference in peak oxygen uptake (V02), carbon dioxide (VC02,), heart rate (HR), minute ventilation (VE), tidal volume (VT), blood lactate or RPE between the two experimental conditions. A total of 12 subjects completed at least 5 stages of the exercise protocol, and their physiological response during exercise with NIV and without NIV were compared. RPE was significantly lower during the first 3 min in the NIV condition than the no NIV condition. Circulating levels of blood lactate were lower (p<0.01) during stage 3 in the NIV than the than no NIV condition. There was no difference in RR, VT, HR, %HR, VE, V 0 2and %V02 between the two experimental conditions during sub maximal exercise. Conclusions: Application of non-invasive ventilatory support prior to exercise improves maximal exercise performance, but has no effect on cardio-metabolic response during submaximal exercise in patients with COPD

Exercise-induced respiratory muscle work: Effects on blood flow, fatigue and performance

This is the post print version of this article. The official published version can be obtained from the link below.In healthy subjects, heavy intensity endurance exercise places substantial demands on the respiratory muscles as breathing frequency, ventilation and the work of breathing rise over time. In the highly trained subject working at high absolute work rates, the ventilatory demand often causes varying degrees of expiratory flow limitation, sometimes accompanied by lung hyperinflation and, therefore, increased elastic work of breathing. Time-dependant increases in effort perceptions for both dyspnea and limb discomfort accompany these increased ventilatory demands. Similar responses to endurance exercise but at much lower exercise intensities also occur in patients with COPD and CHF. Note that these responses significantly influence exercise performance times in both health and disease. This effect was demonstrated by the marked reductions in the rate of rise of effort perceptions and the enhanced exercise performance times elicited by unloading the respiratory muscles using pressure support ventilation or proportional assist mechanical ventilation. In healthy fit subjects, unloading the inspiratory work of breathing by about one half increased performance by an average of 14% (Harms et al. 2000), and in CHF and COPD patients performance time more than doubled with respiratory muscle unloading (O’Donnell et al. 2001). Why are effort perceptions of limb discomfort markedly reduced and exercise performance increased when the respiratory muscles are unloaded? Our hypothesis is shown in Fig. 1

Wearing colored glasses can influence the exercise performance and testosterone concentration

Perception of red color is associated with higher testosterone concentration and better human performance. Thus, we evaluated the acute effects of wearing colored-lens glasses on the YoYo intermittent endurance exercise test 2 (YoYoIE2) performance indicators and testosterone concentration. Ten soccer players performed three YoYoIE2 (counterbalanced crossover) wearing colorless (control), blue- or red-lensed glasses (2–4 days of rest in between). YoYoIE2 performance did not differ among the trials (p>0.05), but blood testosterone increased post-exercise in red compared to red baseline (red=14%, effect size=0.75). Analysis showed faster heart rate recovery (p0.05) among the trials. Wearing red-colored lenses during high-intensity intermittent exercise increased testosterone concentration, but do not influence performance

Durability of Benefits From Supervised Treadmill Exercise in People With Peripheral Artery Disease.

Background It is currently unknown whether 6 months of supervised treadmill exercise has a durable benefit on 6-minute walk performance, even after exercise is completed, in people with peripheral artery disease. Methods and Results A total of 156 participants with peripheral artery disease were randomized to 1 of 3 groups: supervised treadmill exercise, supervised resistance training, or attention control. Participants received supervised sessions during months 1 to 6 and telephone contact during months 6 to 12. Primary outcomes were change in 6-minute walk distance and short physical performance battery at 6-month follow-up and have been reported previously. Secondary outcomes were change in 6-minute walk and short physical performance battery at 12-month follow-up and are reported here. A group of 134 participants (86%) completed the 12-month follow-up. At 6-month follow-up, compared with control, 6-minute walk distance improved in the treadmill exercise group (+36.1 m, 95% CI =13.9-58.3, P=0.001). Between 6- and 12-month follow-up, 6-minute walk distance significantly declined (-28.6 m, 95% CI=-52.6 to -4.5, P=0.020) and physical activity declined -272 activity units (95% CI =-546 to +2, P=0.052) in the treadmill exercise group compared with controls. At 12-month follow-up, 6 months after completing supervised treadmill exercise, change in 6-minute walk distance was not different between the treadmill exercise and control groups (+7.5, 95% CI =-17.5 to +32.6, P=0.56). There were no differences in short physical performance battery change between either exercise group and control at 6-month or 12-month follow-up. Conclusions A 6-month supervised treadmill exercise intervention that improved 6-minute walk distance at 6-month follow-up did not have persistent benefit at 12-month follow-up. These results do not support a durable benefit of supervised treadmill exercise in peripheral artery disease. Clinical Trial Registration URL : https://www.clinicaltrials.gov . Identifier: NCT 00106327