Water and electrolyte replenishment in the exercising child

Abstract

This article reviews studies, mostly from the authors' laboratory, on children's sweating rates and composition, voluntary drinking patterns during prolonged exercise in the heat, taste perception of beverages, and the importance of fluid flavor and composition in preventing voluntary dehydration. Subjects were children, exposed for 90 to 180 min to intermittent bouts of cycling (45-50% maximal O2 uptake) in a climatic chamber (mostly at 35 degrees C, 40-50% relative humidity). There were five main findings: When given unflavored water ad libitum, children dehydrated progressively and their core temperature increased faster than in adults. When offered drinks with various flavors, children preferred grape to other flavors. When given grape-flavored water during intermittent exercise in the heat, children voluntarily drank 44.5% more than with unflavored water. When given grape-flavored carbohydrate-electrolyte solution, they voluntarily drank 91% more than with unflavored water. Finally, such consumption of carbohydrate-electrolyte solution was sufficient to prevent voluntary dehydration during 180-min intermittent exercise in the heat.