Post-exercise Rehydration: Potassium-rich Drinks vs. Water and a Sports Drink

Abstract

Fluid retention, thirst quenching, tolerance, and palatability of different drinks were assessed. On four different days, 12 healthy, physically active volunteers (24.4 ± 3.2 years old, 74.75 ± 11.36 kg body mass (mean ± S.D)), were dehydrated to 2.10 ± 0.24% BM by exercising in an environmental chamber (32.0 ± 0.4 ºC db, 53.8 ± 5.2% rh). Each day they drank one of four beverages, in random order: fresh coconut water (FCW), bottled water (W), sports drink (SD) or potassium-rich drink (NEW); volume was 120% of weight loss. Urine was collected and perceptions self-reported for three hours. Urine output was higher (p < 0.05) for W (894 ± 178 mL) than SD (605 ± 297 mL) and NEW (599 ± 254 mL). FCW (686 ± 250 mL) was not different from any other drink (p > 0.05). Fluid retention was higher for SD than W (68.2 ± 13.0% vs. 51.3 ± 12.6%, p = 0.013), but not for FCW and NEW (62.5 ± 15.4% and 65.9 ± 15.4%, p > 0.05). All beverages were palatable and well tolerated; none maintained a positive net fluid balance after three hours, but deficit was greater in W vs. SD (p = 0.001). FCW scored higher for sweetness (p = 0.03). Thirst increased immediately after exercise but returned to baseline after drinking a small volume (p < 0.0005). In conclusion, additional potassium in FCW and NEW did not result in additional rehydration benefits over those already found in a conventional sports drink with sodium.