BCAAs (Branched-Chain Amino Acids) are branched-chain amino acids consisting of leucine, isoleucine, and valine, which the body cannot produce itself and must obtain through food. BCAAs play an important role in stimulating protein synthesis in the muscles themselves and therefore contribute to muscle mass building. They are also important during physical exertion, as they can be broken down in our muscles and thus serve as an energy source. But they can do even more – since the body uses them to produce proteins, they are essential for bones, muscles, and the immune system and regulate energy supply and blood sugar levels.