The Effects of Increased Electrolyte Concentrations on Net Body Fluid

Dehydration during and after exercise is prevalent in athletes. Due to a thirst mechanism that does not entirely replenish total body water lost during exercise, it is crucial to rehydrate efficiently with sufficient fluids and electrolytes to retain fluid intake. The study aimed to observe the effectiveness of rehydration with different commercially available drinks and plain water. The rehydration was assessed over 4 hours after a 2% exercise-induced dehydration in the heat. Rehydration was equal to 150% of fluid loss via exercise and was administered in four equal doses during the first 60 minutes of the rehydration period. The average exercise-induced dehydration was 2.11 ± 0.4%. The high sodium and potassium-containing drink, GoodSport, had significantly better rehydration at the four-hour time point (-0.44 ± .21) than in Gatorade (-0.71 ± 0.16; P = 0.0273), Body Armor (-1.00 ± 0.5; P < 0.0001), and water (-0.88 ± 0.39; P = 0.0015). Similarly, GoodSport resulted in lower urinary output than the other drinks. Results from this study indicate that the intake of a high sodium and potassium-containing sports drink after exercise improves net fluid balance more than drinks with lower electrolyte concentrations.