Amino acids and endurance exercise

Although skeletal muscle is capable of oxidizing selected amino acids, exer cise in the fed and carbohydrate-replete condition results in only a small increase in amino acid utilization. Nevertheless, it may be important to in crease the dietary protein requirements of active individuals. There is ong oing debate as to whether the amino acids for oxidation are derived from th e free amino acid pool, from net protein breakdown, or a combination of bot h. There has been interest in the potential ergogenic benefits of amino aci d ingestion; however, BCAA ingestion does not appear to affect fatigue duri ng prolonged exercise, there is little support from controlled studies to r ecommend glutamine ingestion for enhanced immune function, and although glu tamine stimulates muscle glycogen synthesis, its addition to carbohydrate s upplements provides no additional benefit over ingestion of carbohydrate al one.