Branch Chain Amino Acids are essential amino acids for humans. This means that our bodies do not synthesize these amino acids naturally, and they have to be consumed through our diet. The 3 BCAAs L-Leucine, Isoleucine, and L-Valine all contribute to protein synthesis. L-Leucine has been shown to be the most important. As the body repairs itself, it uses amino acids to build the protein molecules that make muscle fiber.  By supplementing BCAAs you are keeping your body anabolic instead growth and repair state.*