Effects of Prior Physical Exertion on Tolerance to Hypoxia, Orthostatic Stress, and Physical Fatigue.

摘要

Ten healthy men, 20-35 years old, were tested for tolerance to hypoxia, orthostatic stress, and physical fatigue after a period of rest, and, on another occasion, after a period of physical exertion. Exertion consisted of four 10-min periods of pedal ergometry; each period consisted of a 30-watt (W) load imposed for 2 min, 60 W for 4 min, and 100 W for 4 min. Testing included a 100-min exposure to an oxygen/nitrogen gas mixture equivalent to 3658 m of altitude, 2 min of lower body negative pressure (LBNP) at -40 torr differential pressure, and 6 min of 50 W pedal ergometry. Psychomotor testing was conducted during hypoxic exposure. Although some statistically significant (p < or = 0.05) physiological decrements were associated with prior physical exertion, psychomotor performance and mentation were not significantly affected. In this study, prior physical exertion produced no adverse effects on physiological tolerances, mentation, or psychomotor performance. (Author)