The FitX BCAA do this by inhibiting the production of serotonin, which often rises during exercise.Serotonin increases the 'perception of fatigue' which means you will tire more during workouts. BCAAs will prevent this from occurring, giving you more energy. Therefore you can workout for longer, push harder, and lift even more weights! The FitX BCAA supplement can help to reduce tiredness, which can significantly boost your workout. BCAAs (such as leucine) stimulate protein synthesis more than regular dietary protein because they have already been broken done into the necessary amino acids that your body requires to carry out the reaction. Therefore the rate of protein synthesis increases.