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.
To understand just how important BCAAs are to muscle building and recovery you need to know what a metabolic pathway is. Put simply, a metabolic pathway is a chain of chemical reactions that takes place within a cell (in this case, a muscle tissue cell). When adequate amounts of BCAAs are ingested they create their own metabolic pathway which results in increased protein production. This means more muscle tissue will be grown and muscles will be repaired faster.
Generally, after a session of resistance training the body is in a catabolic (the breaking down of muscle tissue) state, with a protein synthesis deficit. This is because post exercise the MAPK signaling pathway (the body’s own way to signal muscle growth) is activated. While this is a pathway that will increase protein synthesis, it is not as effective as when combined with the BCAA signaling cascade.
The two pathways act independent of each other. Because of this, when adequate amounts of BCAAs are ingested post workout (usually in the form of a post-workout drink) the body is placed in a greater state of hypertrophy with a positive amount of protein synthesis. This is extremely important for athletes because it will decrease recovery time as it increases the rate at which lean body mass is gained.