Abstract
POSITIVE, PHYSIOLOGICAL STRESS, DYSFUNCTION
Physical performance decrements observed during multi‐stressor military operations may be attributed, in part, to cellular membrane dysfunction, which is quantifiable using phase angle (PhA) derived from bioelectrical impedance analysis (BIA). Positive relationships between PhA and performance have been previously reported in cross‐sectional studies and following longitudinal exercise training programs, but whether changes in PhA are indicative of acute decrements in performance during military operations is unknown. Data from the Optimizing Performance for Soldiers II study, a clinical trial examining the effects of exogenous testosterone administration on body composition and performance during military stress, was used to evaluate changes in PhA and their associations with physical performance. Recreationally active, healthy males (Military operations induce decrements in bioelectrical impedance analysis phase angle, indicating cellular membrane disruption. Phase angle was associated with strength and power performance, but not aerobic capacity, before and in recovery from the operation. However, changes in phase angle measured immediately after the operation were not associated with changes in performance, indicating that phase angle may be related to strength and power in non‐stressed conditions, but not a reliable indicator of performance during severe physiological stress.
Trial registration: 