Fluid is important to prevent over heating and dehydration. Because muscles heat up during exercise extra fluid is needed to maintain the blood volume so that the circulating fluid can reach into the muscles and carry the heat away to the skin. The heat is released by primarily by sweating . Sweating, without replacement fluids can lead to dehydration. More than any other nutritional factor, too little fluid can effect your young athlete.
Children are particularly vulnerable to the effects of fluid imbalance.
That is because they don't handle heat well, they get hotter during exercise, and their hearts have a lower blood output. Be sure your child drinks water before, during, and after exercise. Supply him with his own water bottle that you can see through. Check regularly to be sure he is drinking. Children may not notice the need for liquid or the signs of overheating.