| dc.description.abstract | It is common to find mild to serious dehydration during exercise in hot, humid conditions. To restore euhydration, the literature shows that a fluid volume larger than sweat loss should be ingested post-exercise; ingestion of enough sodium is essential to support retention of the ingested fluid. PURPOSE AND METHODS. The purpose of this study was to compare the effectiveness of three fluids in promoting fluid retention and maintaining euhydration in a warm, humid environment. Nineteen heat-acclimated male athletes, 11-15 years old, drank a volume of water (W), coconut water (C) (0.9 mEqL-1 Na+, 63.3 mEqL-1 K+, 4% CHO), or sports drink (SD) (20.2 mEqL-1 Na+, 3.2 mEqL-1 K+, 6% CHO) equivalent to 125% of body weight loss, after exercise-induced dehydration to 2.3% body mass (BM). Natural wet bulb globe temperature (WBGT) in the shade for both the exercise and recovery periods was 26.5 +- 0.6°C. All subjects performed all trials, in random order, separated by at least 5 days. RESULTS. There were no significant differences (p>0.05) in initial body mass (50.62 +- 7 kg) for the three conditions. Urine production during the three-hour, at-rest follow up was 27.7 +- 16.8% (W), 25.2 +- 13.8% (C), and 22.2 +- 15.4% (SD) of fluid ingested (p>0.05). However, final body mass was significantly lower for W (49.6 +- 7.0 kg) than for either C (49.9 +- 7.1 kg) or SD (49.8 +- 7.0 kg) (p<0.05). After these 3 hours of recovery, hypohydration was worse for W (1.98%BM) than for both C (1.52%BM) and SD (1.46%BM) (p<0.05). CONCLUSIONS. Additional sweat output at rest prevented maintenance of euhydration after three hours of recovery in a warm, humid climate, in spite of ingestion of 125% of the volume lost in sweat during exercise. Water was less effective at fluid retention than either coconut water or a sports drink. | |
