No Effect of Moderate Hypohydration or Hyperthermia on Anaerobic Exercise Performance

Med Sci Sports Exerc. 2006 Jun;38(6):1093-7. doi: 10.1249/01.mss.0000222838.74015.15.

Abstract

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 at three time points after passive heat exposure to include immediately (0 min), 30 min, and 60 min after in a temperate environment (22 degrees C). Rectal temperature (Tc) was measured throughout the experiment.

Results: HYP reduced body mass (2.7+/-0.7%) (P<0.05) but had no effect on any WAnT performance measure. Passive heat exposure elicited moderate hyperthermia in both trials (EUH: 0.6 degrees C; HYP: 1.0 degrees C) 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 affect anaerobic exercise performance in a temperate environment.

MeSH terms

  • Adult
  • Anaerobic Threshold / physiology*
  • Body Temperature / physiology
  • Body Weight / physiology
  • Climate
  • Cross-Over Studies
  • Dehydration / physiopathology*
  • Environmental Exposure
  • Exercise Test
  • Fatigue / physiopathology
  • Follow-Up Studies
  • Heat Stress Disorders / physiopathology*
  • Hot Temperature
  • Humans
  • Humidity
  • Male
  • Rehydration Solutions / administration & dosage
  • Single-Blind Method
  • Time Factors

Substances

  • Rehydration Solutions