Beverage Content Influences Voluntary Fluid Intake During Exercise

Voluntary fluid intake is known to be impacted by the palatability of fluid. Beverage content, including flavor, nutrient content, and acidity are potential impacting factors of palatability, however it is unknown how these may impact fluid intake. PURPOSE: To describe the influence of beverage content on voluntary fluid consumption during exercise. METHODS: Nine studies were included with adult (>18 y.o.) human subjects (n=190). Experimental beverages with flavor or nutrient content were compared to water and unrestricted consumption during exercise. Cohen’s d effect sizes (ES) were calculated to compare consumption of beverages with various contents differing from plain water, and mean difference (MD) and 95% confidence intervals (CI) were calculated for meta-analysis. RESULTS: A large effect (ES=9.81; p<0.001) represented a 37% greater total fluid consumption of a carbohydrate-electrolyte beverage over water (n=6; MD[CI]=0.54 L [0.43-0.65]). A large effect (ES=11.01; p<0.001) represented a 34% higher fluid consumption rate of a carbohydrate-electrolyte beverage over water was revealed (n=6; MD[CI]=0.26 L/h [0.21-0.30]). A large effect (ES=12.07; p<0.001) represented a 51% lower body mass loss with the consumption of a carbohydrate-electrolyte beverage over water (n=5; MD[CI]=0.41 kg [0.20-0.29]).Various flavors of carbohydrate-electrolyte beverages were preferable to water during exercise (p<0.005), and acidified beverages were less preferable than water during exercise (p<0.05). CONCLUSION: Flavored or nutrient containing beverages, such as sports drinks, are shown to be consumed at both a higher volume and faster rate than plain water during exercise. When fluid consumption needs are high, utilization of a flavored or nutrient containing beverage improves fluid consumption and mitigates dehydration during exercise.