Amino acids promote protein synthesis after training

The branched-chain amino acids(BCAAs) include leucine, isoleucine and valine. These amino acids are essential amino acids, which means that they must be supplied through food. They make up 33 percent of skeletal muscle and are rapidly metabolized during training. Branched-chain amino acids are also essential for muscle protein synthesis. Many bodybuilders and other athletes use BCAA supplements to promote protein synthesis and regeneration after training. BCAAs serve as building blocks of protein and activate signaling proteins in the muscles that initiate protein synthesis and increase the size of muscle fibers.

Chemicals called ribosomal protein S6 kinase and mTor (target of rapamycin) are important signaling molecules for protein synthesis. They are sensitive to BCAAs (especially leucine) and work like biological computer programs to string together the amino acids needed to build new muscle tissue.

Bodybuilders should take carbohydrate amino acid supplements rich in BCAAs before and after training to maximize protein synthesis. These supplements activate signaling pathways within the cells that promote protein synthesis in the muscles and modify muscle protein breakdown and muscle remodeling and repair. While BCAA supplements promote recovery and immune function, they do not appear to enhance athletic performance or serve as a significant source of energy during exercise.
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