Effect of Cold vs Temperate Conditions on Physical Performance During Extended Mountain Warfare Training at Moderate Altitude.

This study investigated the effects of environmental conditions on body composition, upper body power, and lower body power during approximately four weeks of military mountain training involving 111 U.S. Infantry Marines. Participants trained under either fall (temperate) or winter (cold, snowy) conditions at moderate altitude (~2100 m), with performance assessed via countermovement jumps and ballistic push-ups at multiple time points before, during, and after training. Results showed that extended military training led to significant declines in explosive lower and upper body performance regardless of season, with no acute effects of altitude detected and only a weak positive correlation between skeletal muscle mass loss and decreased lower body power. The findings suggest that physical power declines during prolonged military training may not fully recover within a month post-training, highlighting the need for targeted recovery strategies and further research into contributing factors such as nutrition, sleep, and cognitive stress.