BCAAs (branched chain amino acids) are the essential aminos leucine, isoleucine, and valine. The combination of these three amino acids makes up approximately 1/3 of skeletal muscle tissue in the human body. BCAAs play a very important role in protein synthesis (the production of proteins in cells from amino acids to build muscle).
Amino acids are the building blocks of protein. When you eat food containing protein, it gets digested through the intestines and stomach. During this process the protein is broken down into individual amino acids and short chains of amino acids. These amino acids are small enough to be absorbed into the bloodstream.
Once the amino acids are absorbed into the bloodstream they have far reaching effects across the entire body. Amino acids are involved in muscle repair (lean muscle building), essential brain functions and even hair growth just to name a few.