Amino Acids / BCAAs sports supplements and bodybuilding nutrition products are the building blocks of protein and so essential for protein synthesis (muscle building). Especially important are the Branched Chain Amino Acids (BCAAs) - leucine, isoleucine and valine - the three aminos that make up 1/3rd of muscle tissue in the body. Supplementation with BCAAS pre and/or post-workout helps to speed up recovery, reduce exercise-induced catabolism (muscle wasting) and improve hypertrophic response to training.