Protein nutrition for the athlete.

Endurance exercise results in a protein catabolic state characterized by decreased protein synthesis, increased amino acid oxidation, and increased conversion of amino acids to glucose. The adaptive response to performance of strength exercise, on the other hand, results in an anabolic state in hypertrophying muscles, and the accretion of protein is the result of increased protein synthesis. Because of changes in protein metabolism there is an increased dietary requirement for protein in both endurance and strength exercise. However, the normal dietary intake of protein is adequate for athletes as long as the energy intake is sufficient to maintain body weight. There is little scientific evidence that consumption of large protein supplements will have any beneficial effect on muscle hypertrophy, muscular strength, or physical performance.