EFFECTS OF HYPOTONIC DRINK ON ENDURANCE AND FLUID BALANCE DURING REPEATED EXERCISES IN HEALTHY SUBJECTS

Abstract

Abstract Purpose: This study aimed to determine and compare the effects of sports drinks on endurance and fluid balance during repeated exercise in young healthy subjects. Methods: Eleven healthy young active males, aged between 18-25 years old, randomly participated in 3 experimental trails of three solutions of placebo (PL), isotonic (ID), and hypotonic drinks (HD). Each trails, they were asked to complete two subsequent cycling exercises: 80% and 50% maximal heart rate of high-intensity intermittent cycling (EX1), and the progressive load up to exhaustion cycling (EX2) with the 1-hour recovery duration between. They drank the double-blind assigned sport drink for 150% of weight reduction from EX1. Fluid balance was determined using urine specific gravity (USG), and blood osmolality. Endurance performance was determined as time-to-exhaustion (TTE) during EX2. Moreover, blood biochemistry was also monitored. All variables were statistical analysis by repeated-measure ANOVA at P-value less than 0.05 of significance. Results: The results show no significant difference of TTE, USG, blood electrolyte, lactate, and lipids among drinks. However, blood glucose was significantly increased after ID compared with other drinks. The reductions in triglycerides in HD during Pre- and Post-Ex2 only. Conclusion: It is concluded that hypotonic drinks can regulate endurance and fluid status during repeated exercises as similar as isotonic drink, even though, it contains less sugar which may be useful for those who need low calories drink.