[The effects of fluid ingestion and its composition on uric acid metabolism during high intensity long term exercise]

The purpose of this study was to analyze the effects of fluid ingestion and its composition on uric acid metabolism after exercise. Six healthy males volunteered for the study which was comprised of three different experiments; Exp. 1, Exp. 2, and Exp. 3. In all the experiments, subjects performed treadmill exercise (70%VO2max) for 70 minutes respectively. For seven hours after exercise, subjects ingested mineral water at 10 degrees C ad-lib in Exp. 1, 1.5 times the volume of mineral water consumed in the first experiment in Exp. 2, and the same volume of sports drink as in the first experiment in Exp. 3. No significant differences were observed in oxygen uptake and heart rate during exercise among the three experiments, so it was considered that the produced serum uric acid (SUA) levels in the three experiments were about the same level. However, the decrease in SUA, urinary uric acid excretion (UUA), clearance of uric acid (CUA) and fractional excretion of uric acid (FEUA) in Exp. 3, in which the sports drink was consumed instead of mineral water were higher than in Exp. 1 and Exp. 2. On the other hand, no significant differences were found in Exp. 2 and Exp. 3. A significant relationship between UUA and FEUA was found among the three experiments, while there was no corrleation between UUA and urine volume. These results show that; 1) the sports drink ingestion can increase the efficiency of recovery from high serum uric acid after exercise, 2) the increase in uric volume due to high mineral water intake does not elevate UUA, and 3) the increase in UUA due to sports drink ingestion was associated with the increase of FEUA.