Health experts agree that proper fluid intake during exercise can reduce the risk of heat-related illnesses.  But parents should be mindful of what their children are drinking.  As children’s activity level increases, so does loss of essential body fluids.  Even when children are thirsty, they might not drink enough because the taste of plain water can be unappealing.  As a result, parents may turn to flavored sports drinks.  However, some sport drinks or energy enhancers may do more harm than good because they contain unhealthy amounts of sugar and caffeine.  Water should be the beverage of choice because it is the main body fluid initially lost during exercise.

Via the American Academy of Pediatrics