Post-Exercise Rehydration in Athletes: Effects of Sodium and Carbohydrate in Commercial Hydration Beverages.

Plain Language Summary

Inadequate fluid intake during sports participation and training can lead to dehydration. Persistent dehydration at or beyond 2% of body mass negatively impacts performance during subsequent efforts and increases the risks of heat illness. Prompt and adequate rehydration between training sessions and competitions is crucial, especially when the period for rehydration is brief before returning to physical and environmental challenges. The study aimed to compare the effects of varying sodium (Na) and carbohydrate (CHO) content in oral rehydration solutions (ORS) and sports drinks (SD) for rehydration following exercise-induced dehydration. This study was a placebo-controlled, randomised, double-blind clinical trial. The study recruited twenty-six athletes who underwent three 90-minute interval training sessions without drinking fluids to induce a 2.6% body mass loss. Results showed that fluid retention was superior in male athletes consuming 100% of fluid needs when beverages contained Na and CHO compared to drinking only water. Varying the CHO and Na within the typical range of sports drinks did not seem to vary for benefit by the end of the 3.5 h period. However, the ORS might be advantageous for earlier rehydration (within 2 h) based on a greater suppression of urine loss detected earlier in the recovery. Authors concluded that the association between fluid retention and Na balance further confirms the role that beverage sodium content can play in rehydration.