The Effect of Hypohydration on Anaerobic Exercise Performance

Abstract

Dehydration, a loss of body water, is common during exercise or work, especially under conditions of extreme heat. In the sport or occupational setting, individuals who are hypohydrated are often required to perform anaerobic exercise. Although it is well known that hypohydration impacts negatively on aerobic exercise performance, the impact of hypohydration on anaerobic exercise performance is less well defined. PURPOSE: This study examined the effect of moderate hypohydration on anaerobic exercise performance. METHODS: Eight healthy, athletic, male subjects (age: 19.6 ± 1.3 yrs; height: 180.1 ± 8.6 cm; weight: 82.6 ± 10.8 kg; VO2max: 46.5 ± 3.8 mls/kg/min) completed two iterations of a 30-second Wingate Anaerobic Power Test: EUHY Wingate, in a well-hydrated condition, and HYPOHY Wingate, under conditions of moderate hypohydration (-3.8 ± 0.6 % body weight). The iterations were randomly assigned and separated by 3-10 days. Exercise tests were conducted at the same time of day. Hydration status was determined by urine specific gravity (USG): EUHY 1.016 ± 0.006; HYPOHY 1.027 ± 0.003 and later confirmed by analysis of plasma osmolality: EUHY 273.0 ± 2.83 mOsm/kg; HYPOHY 293 ± 0.2.83 mOsm/kg. RESULTS: Paired t-tests demonstrated no significant differences between treatment conditions (EUHY vs. HYPOHY) in mean power (EUHY: 663.08 ± 90.30 watts vs. HYPOHY: 641.40 ± 70.01 watts) p = 0.52 and in mean power/kg BW (EUHY: 8.37 ± 1.24 watts/kg BW vs. HYPOHY: 8.31 ± 0.95 watts/kg BW) p = 0.89. CONCLUSION: Results indicate that moderate hypohydration does not impair anaerobic exercise performance in young, athletic males.