Supplementing with BCAA's can result in measurable gains in both strength and muscularity. Taking branch chain amino acid before and during a work out will increase performance and delay fatigue . Since your body can not manufacture BCAA's, they must be supplied through your diet. These amino acids are needed for the maintenance of muscle tissue during physical stress and intense exercise. From the perspective of athletes, BCAA's function as anabolic agents, which allow the body to burn fat and not muscle. Therefore, branch chain amino acids are crucial in your quest for muscle growth.