Out of the nine essential amino acids, three are key to gaining and maintaining muscle: leucine, isoleucine, and valine. These important amino acids are the building blocks of protein, and they are given the title “Branched Chain Amino Acids,” or BCAAs. These amino acids can be consumed through food and further from supplementation. BCAAs increase protein synthesis, reduce protein breakdown, and allow for a better workout.
Firstly, BCAAs can directly increase the rate of the metabolic process of protein synthesis. In doing so, they also reduce protein breakdown. An increased BCAA level will decrease the expression of several complexes involved in protein breakdown through decreasing the amount of mRNA produced for that task. These two factors are key to muscle gain through hypertrophy: increasing synthesis and decreasing breakdown of proteins.
Second, amino acid supplementation has also proven to provide a more intense workout. Branched-chain amino acids reduce the amount of tryptophan released to the brain. Tryptophan gets converted to serotonin which makes people feel more fatigued. Due to the decrease of serotonin production, BCAAs may allow for a more intense and drawn-out resistance training session. This effect in confirmed by a study titled, “Daily L-leucine supplementation in novice trainees during a 12-week weight training program.” In the study, it was found that four grams of L-leucine per day enhances strength performance during a 12-week resistance training program of initially untrained male participants.
Third, branched-chain amino acids regulate glucose. With sufficient BCAA levels, glucose uptake and insulin sensitivity can be improved. They produce most of the blood sugar during workouts. Proper BCAA supplementation can result in an insulin response that helps transport aminos into cells to repair muscle damage and build muscle tissue.