Research shows that milk is one of the best beverages for hydration, even better than water or sports drinks. Researchers credit milk’s natural electrolytes, carbohydrates, and protein for its effectiveness.
Seven healthy men exercised to dehydration three different times and then drank fat-free milk, a carbohydrate-based sports drink or water. The research team found that the fat-free milk replenishes lost electrolytes and helped them rehydrate more effectively compared to water or sports drinks — in part due to milk’s natural protein and other essential nutrients.1
Researchers developed a beverage hydration index, comparing the hydration effect of 13 beverages among 72 healthy, physically active men, and they found fat-free and full-fat milk were among the top-ranked beverages with fat-free milk being ranked first. Both types of milk improved hydration status and kept the men hydrated longer compared to other beverages including water and a sports drink. Researchers attributed milk’s beneficial hydration effect to the combination of its macronutrient and electrolyte levels.2
According to one study, drinking lowfat or fat-free milk after exercise could restore hydration better than other popular post-exercise beverages. The study compared the rehydration effectiveness of four beverages: lowfat milk, lowfat milk with added sodium, water and a sports drink. After exercise in a warm climate, participants were given one of the four test beverages and the researchers measured hydration status. While all beverages restored hydration status equally, the researchers found that milk may be more effective than water or sports drinks at maintaining normal hydration status after exercise, likely due to milk’s electrolyte content and energy density.3
1. A Metered Intake of Milk Following Exercise and Thermal Dehydration Restores Whole-Body Net Fluid Balance Better Than a Carbohydrate–Electrolyte Solution Or Water in Healthy Young Men. British Journal of Nutrition.