Amino Vital Endurance Mix & Shake Endurance Drink Mix: To perform your best, your body needs amino power. Amino acids are the building blocks of protein as well as the "construction material" of your body's muscles and vital organs. During exercise, branched-chain amino acids (BCAAs: leucine, isoleucine and valine) are a critical source of energy for muscle exertion. Amino Vital sports scientists have determined the combination of amino acids that best supports greater fitness and higher performance: BCAAs for muscle nourishment plus arginine and glutamine for overall, long-term health and wellbeing. Amino Vital Endurance has amino acids, carbohydrates and a carefully balanced supply of electrolytes to energize your body while reducing fatigue and maintaining focus during your workout.