Water and electrolyte replenishment in the exercising child

Area of Science:

• Exercise Physiology
• Pediatric Sports Medicine
• Environmental Physiology

Background:

• Children exhibit different hydration and thermoregulation responses compared to adults during exercise.
• Voluntary fluid intake is crucial for preventing dehydration and maintaining performance in heat.

Purpose of the Study:

• To investigate children's fluid intake, taste preferences, and hydration status during prolonged exercise in heat.
• To determine the impact of fluid flavor and composition on voluntary drinking patterns in children.
• To assess the effectiveness of flavored carbohydrate-electrolyte solutions in preventing dehydration in exercising children.

Main Methods:

• Children performed intermittent cycling exercise (45-50% maximal O2 uptake) for 90-180 minutes in a climatic chamber (35°C, 40-50% RH).
• Fluid intake was measured with ad libitum access to unflavored water, flavored water, or flavored carbohydrate-electrolyte solutions.
• Beverage palatability and preference (e.g., grape flavor) were assessed.

Main Results:

• Children dehydrated progressively and experienced faster core temperature increases when drinking unflavored water compared to adults.
• Children preferred grape flavor over other tested flavors.
• Voluntary fluid intake increased by 44.5% with grape-flavored water and 91% with grape-flavored carbohydrate-electrolyte solution compared to unflavored water.
• Consumption of the carbohydrate-electrolyte solution prevented voluntary dehydration during 180 minutes of exercise.

Conclusions:

• Fluid flavor significantly enhances voluntary fluid intake in children during exercise in the heat.
• Grape-flavored carbohydrate-electrolyte solutions are effective in promoting adequate hydration and preventing dehydration in exercising children.
• These findings highlight the importance of palatable and appropriately composed fluids for pediatric hydration during physical activity in warm environments.