A Comparison of Hyperhydration Versus Ad Libitum Fluid Intake Strategies on Measures of Oxidative Stress, Thermoregulation, and Performance

Abstract

Dehydration has been shown to augment cellular stress. Glycerol hyperhydration can delay dehydration, which may decrease the level of pre- and post-exercise oxidative stress. This study aimed to compare the effects of glycerol (G) or water (W) hyperhydration with no hyperhydration (C) on oxidative stress, thermoregulation, and cycle performance. Seven trained males consumed 1.2 g of glycerol·kg⁻¹ body mass (BM) in 26 ml·kg⁻¹ BM water or equal volume water to achieve hyperhydration followed by a 90 min time trial. Total glutathione increased post exercise (PE) in all trials (p < 0.01), while oxidized glutathione (p < 0.05) and protein carbonyl concentrations (p < 0.001) were increased PE for the C trial only. Mean body temperature and heart rate increased with exercise but were not different between interventions. Total distance covered and power outputs were not different between interventions. Fluid intake attenuated oxidative stress but did not enhance thermoregulation or performance.

Keywords:

• fluid balance
• glutathione
• protein carbonyl

Acknowledgments

The authors thank the subjects for their enthusiasm and participation.