THE AMAZING MUSCLE BCAA PUNCH BCAA or Branched Chain Amino Acids are the building blocks of protein. Amino acids are necessary for growth and repair of muscles and issues. Without them, protein in the body breaks down, resulting in muscle loss. Branched Chain Amino Acids (BCAAs) Includes L-Leucinie, I-Isoleucine and L-Valine. These amino acids can be taken in supplement form before, during or after workout to help improve exercise performance and endurance in addition to potentially aiding in muscle recovery.