Branched-chain amino acids (BCAAs) are best known for their influence on improved muscle growth and exercise performance. They may also help with weight loss and reducing fatigue after exercise. Amino acids are the building blocks of protein in our body. Commonly found in supplement capsules or powder form, BCAAs are made up of the three essential amino acids – leucine, isoleucine, and valine. They are commonly found in protein-rich foods such as meat, dairy, and legumes.