Cardiovascular and perceptual responses to dehydration, oral and intravenous saline rehydration, and subsequent exercise in the heat.

摘要

Athletes strive to maintain adequate hydration during exercise in the heat by drinking, and more recently by saline infusion. The purpose of this investigation was to compare perceptual and cardiovascular responses to oral and intravenous saline rehydration at rest and during subsequent exercise in the heat. Eight unacclimatized males underwent four randomly assigned rehydration treatments following a 2-4 hour exercise-induced dehydration bout to reduce body weight by 4%. Rehydration treatments included 0.9% saline infusion (09IV), 0.45% saline infusion (45IV), no fluid (NF), and 0.45% saline oral ingestion (ORAL). Following rehydration and rest (2 h total), subjects walked at 50% VO2max for 90 min at 36