Athletes, even body builders, require only small increases over normal needs in order to support muscle growth. Americans already eat more protein than they need, almost two-fold, so protein needs for muscle development are being met before strength training begins. Excess protein is used as energy and can be stored as body fat. Amino acid supplements and excessively high intakes of protein are not recommended. They can increase calcium loss, and put an added burden on the kidneys which are required to filter the excess nitrogen protein provides.
Water is the most important, yet over-looked, nutrient by athletes.
Water and fluids are essential to maintaining good hydration and body temperature. Sweat losses to keep the body cool can exceed several liters in a 1-hour period. 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.