Medicine & Science in Sports & Exercise (original) (raw)
News & Views from the Editor-in-Chief: Andrew M. Jones
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Fitness, fatigue, rehabilitation after illness or injury, exercise testing, and training to enhance function and performance are abiding topics of articles published in MSSE. Accordingly, my highlighted articles this month extend our understanding of the underlying mechanisms and/or provide implications for practice in these important areas.
In “COVID-19's Impact on Athletes: Reduced Cardiorespiratory Fitness after a SARS-CoV-2 Infection," Hasler and colleagues provide compelling evidence of COVID-19's effects on athletic performance using longitudinal data from over 2,300 athletes, including those with and without SARS-CoV-2 infections. Despite infections being only mild to moderate, the study reveals significant declines in cardiorespiratory fitness - such as power output and VO2max - within 60 days post-infection, alongside heart rate changes suggesting cardiopulmonary and vascular impacts. These findings highlight the multifaceted impact of SARS-CoV-2 on athletic performance and the critical need for tailored recovery strategies. This work offers valuable insights for athletes and practitioners, with implications that may extend to understanding and also managing other seasonal febrile diseases.
Females often show greater fatiguability resistance than males during isometric contractions, but evidence on sex differences in the integrative response during dynamic exercise remains limited. In “Mitochondrial Influence on Performance Fatigability: Considering Sex Variability," Giuriato and colleagues explore the interplay between performance fatigability, cardiovascular responses, and muscle metabolism during a single-limb dynamic task-to-exhaustion. The findings reveal a distinct fatiguability pattern in females, characterized by less of a decrease in muscle maximal force and contractility after exercise, despite similar total work and exhaustion times. During the task-to-exhaustion, comparable VO2 was reached, but females relied more on increasing heart rate, suggesting sexual dimorphism in cardiovascular regulation. Notably, mitochondrial complex II activity negatively correlated with fatigability, highlighting its essential role in fatigue development.
The gas exchange threshold (GET) and lactate threshold (LT) are recognized as key markers distinguishing moderate and heavy intensity aerobic training in humans. However, in rats, GET has not been identified, and the physiological roles of these thresholds remain unclear. In “Setting Treadmill Intensity for Rat Aerobic Training Using Lactate and Gas Exchange Thresholds," Inoue and colleagues demonstrate that GET appears synchronously with LT during incremental exercise in rats, and both serve as valid intensity markers that influence training effectiveness. Specifically, these thresholds were observed at 41-66% of maximum oxygen uptake (VO2max). Also, training above, but not below, these thresholds improved both maximal and submaximal aerobic capacities (VO2max, GET, LT). These findings provide useful information for setting exercise intensity in rats and offer a foundation for translating intensity-based exercise research to human exercise prescription.
Andrew M. Jones