No Effect of Moderate Hypohydration or Hyperthermia on Anaerobic Exercise Performance

摘要

Purpose: This study examined the effects of hypohydration and moderate hyperthermia (core temperature elevation) on anaerobic exercise performance in a temperate environment. Methods: Eight active males completed two passive heat exposure trials (180-min, 45 degrees C, 50%rh) with (EUH) and without (HYP) fluid replacement. A single 15-s Wingate Anaerobic Test (WAnT) was used to assess anaerobic performance (peak power, mean power, and fatigue index) before (-180-min) and again a three time points after passive heat exposure to include immediately after (0-min), 30-min and 60-min post in a temperate environment (22 degrees C). Rectal temperature (Tc ) was measured throughout the experiment. Results: HYP reduced body mass (2.7 plus or minus 0.7%) (P<0.05) but had no effect on any WAnT performance measure. Passive heat exposure elicited moderate hyperthermia in both trials (0.6 degrees C, EUH vs. 1 .0 degree C, HYP) and returned to baseline within 30-60-min following similar decay curves. HYP Tc remained higher (0.4 degrees C) than EUH throughout testing (P<0.05), but moderate hyperthermia itself produced no independent effect on anaerobic exercise performance in either trial. Conclusions: This study demonstrates that neither moderate HYP, nor the moderate hyperthermia accompanying HYP by passive heat exposure, affects anaerobic exercise performance in a temperate environment.