The efficacy of inspiratory muscle training (IMT) has been the subject of considerable controversy in terms of whether it is beneficial to endurance athletes and because a convincing physiological rationale has not been identified to explain its mechanism of action. Early studies suggested that IMT was an ineffectual intervention for gains in either maximal aerobic power or endurance-specific performance. More rigorous recent research supports the observation that maximal aerobic power is not receptive to IMT; however, closer evaluation of both early and contemporary research indicates that responses to endurance-specific performance tests are sensitive to IMT. As the aim of endurance training is to improve endurance performance rather than maximal aerobic power, it is plausible that IMT may be useful in specific performance-related circumstances. Performance adaptations following IMT appear to be connected with post training reports of attenuated effort sensations, but this common observation has tended to be overlooked by researchers in preference for a reductionist explanation. This commentary examines the pertinent research and practical performance implications of IMT from the holistic perspective of complex central metabolic control.
Andrew M. Edwards and Raewyn E. Walker
David B. Pyne, Joshua H. Guy, and Andrew M. Edwards
Heat and immune stress can affect athletes in a wide range of sports and environmental conditions. The classical thermoregulatory model of heat stress has been well characterized, as has a wide range of practical strategies largely centered on cooling and heat-acclimation training. In the last decade evidence has emerged of an inflammatory pathway that can also contribute to heat stress. Studies are now addressing the complex and dynamic interplay between hyperthermia, the coagulation cascade, and a systemic inflammatory response occurring after transient damage to the gastrointestinal tract. Damage to the intestinal mucosal membrane increases permeability, resulting in leakage of endotoxins into the circulation. Practical strategies that target both thermoregulatory and inflammatory causes of heat stress include precooling; short-term heat-acclimation training; nutritional countermeasures including hydration, energy replacement, and probiotic supplementation; pacing strategies during events; and postevent cooling measures. Cooperation between international, national, and local sporting organizations is required to ensure that heat-management policies and strategies are implemented effectively to promote athletes’ well-being and performance.
Marcus B. Stone, Jeffrey E. Edwards, Catherine L. Stemmans, Christopher D. Ingersoll, Riann M. Palmieri, and B. Andrew Krause
Despite recent evidence to suggest that exercise-associated muscle cramps (EAMC) might be primarily of neuromuscular origin, the authors surmise that most information available to certified athletic trainers (ATCs) emphasizes the role of dehydration and electrolyte imbalance in EAMC.
To investigate ATCs' perceptions of EAMC.
7-question, Web-based, descriptive, cross-sectional survey.
Main Outcome Measures:
Responses to 7 questions regarding the cause, treatment, and prevention of EAMC.
Responders indicated humidity, temperature, training, dehydration, and electrolyte imbalance as causative factors of EAMC. Fluid replacement and stretching the involved muscle were identified as very successful in treating and preventing EAMC. Proper nutrition and electrolyte replacement were also perceived as extremely successful prevention strategies.
ATCs' perceptions of the cause, treatment, and prevention of EAMC are primarily centered on dehydration and electrolyte imbalance. Other prominent ideas concerning EAMC should be implemented in athletic training education.
Nicholas W. Baumgartner, Anne M. Walk, Caitlyn G. Edwards, Alicia R. Covello, Morgan R. Chojnacki, Ginger E. Reeser, Andrew M. Taylor, Hannah D. Holscher, and Naiman A. Khan
Background: Physical inactivity and excess adiposity are thought to be detrimental to physical and cognitive health. However, implications of these interrelated health factors are rarely examined together; consequently, little is known regarding the concomitant contribution of physical activity and adiposity to cognition. Methods: Bivariate correlations and hierarchical linear regressions were conducted among a sample of adults between 25 and 45 years (N = 65). Attentional inhibition was assessed using an Eriksen Flanker task. Whole-body percent body fat (%Fat) was assessed using dual-energy X-ray absorptiometry. Daily percent time spent in moderate to vigorous physical activity (%MVPA) was monitored using an accelerometer (7 d). Results: After adjusting for significant covariates, %MVPA was a positive predictor of accuracy in the incongruent task (β = 0.31, P = .03). Individuals who engaged in greater %MVPA exhibited superior attentional inhibition. Additionally, there was an interaction effect of %Fat and %MVPA on attentional inhibition (β = 0.45, P = .04). Conclusion: The positive influence of MVPA on cognitive control persists following the adjustment of significant covariates and adiposity. Additionally, interactive effects between %Fat and %MVPA suggest that individuals with lower activity and greater adiposity exhibited poorer attentional inhibition. These findings have relevance for public health given the elevated rates of physical inactivity and obesity.