Abstract:
The purpose of this study was to examine the effects of sports drink intake on endurance performance, in concomitant with cardiorespiratory, blood chemistry, and metabolic variables. Fourteen healthy males with ages ranged from 18-25 years old participated in 3 trials, with 1 week apart. Three consecutive occasions in each trial, including glycogen depletion, recovery period and endurance exercise (cycling at 70%VO2peak), were employed. During 2 hours recovery period, subjects were randomly assigned to three kinds of fluid intake including sports drink (SD, 10สrbohydrate, 0.16%electrolytes, placebo (PL, 10สrbohydrate); and plain water (WT). The time to exhaustion and work done, cardiorespiratory, blood lactate and glucose concentrations and metabolic variables were recorded. The results showed longer time to exhaustion in SD (52.93 ± 6.98 min) than PL (45.05 ± 4.47 min) and WT (37.95 ± 4.92 min), but significant difference was only observed between SD and WT (p<0.05). Significantly higher work done under SD and PL compared with WT, significantly higher ejection fraction (EF) (p<0.05) in SD than WT. Moreover, significantly lower minute ventilation under SD than PL and WT (p<0.05). There was no difference in blood lactate, blood glucose among three groups. It can be concluded that carbohydrate with electrolytes did not affect cardiorespiratory function, as well as blood chemistry profiles. However, additional electrolytes in sports drink tend to exhibit further exhaustive time.