Branched Chain Amino Acids (BCAAs) is easily one of the best supplements you can take for aiding your fitness goals. One of the biggest reasons to use BCAAs is to improve your physical performance. Scientific evidence shows that they may help build muscles, reduce workout fatigue and decrease muscle soreness after exercise. Studies show that 5-10 grams of BCAA prior to or during your workout helps reduce muscle fatigue, improves muscle recovery, and increases energy levels.