Adolescents and adults should replace any lost body weight lost during a exercise with equal amounts of fluids. A good indication that you have fully rehydrated is to check to see if your urine is clear. Cool water is the best choice. Drink plenty of water, juice and milk. Avoid caffeine containing beverages.
Caffeine is a diuretic and promotes fluid loss.
Drink plenty of fluid before, during, and after exercise. Changing body weight to improve performance must be done safely and effectively or it may do more harm than good. Maintaining an unrealistically low body weight, rapid weight loss , and unnaturally suppressing weight gain can have negative health effects so it is important to set realistic body weight goals. The Food Guide Pyramid is an excellent resource to ensure adequate food intake to meet vitamin and mineral needs while safely achieving body composition goals.