Isoleucine is an essential amino acid that along with leucine and valine makeup the branched chain amino acids (BCAA). This amino acid cannot be manufactured in the body, and needs to be supplied in the diet. Isoleucine is thought to play the biggest role in increasing endurance and helping heal, repair and grow muscle tissue damaged from injury and strenuous exercise and training. Isoleucine is especially important to serious athletes and body builders because of its role in boosting energy production and assisting the body recover from strenuous physical activity.
Isoleucine, together with the other two branched-chain-amino-acids promote muscle recovery after physical exercise and on its own it is needed for the formation of hemoglobin as well as assisting with regulation of blood sugar levels as well as energy levels. It is also involved in blood-clot formation.
Therapeutic doses of isoleucine may be very helpful in preventing muscle wasting and promoting tissue repair after surgery or trauma. Substantial evidence in the literature supports the anabolic effects of branched-chain amino acids on muscle protein synthesis. Supplementation with isoleucine may, therefore, have a positive effect on increasing muscle protein in those who are suffering from muscle protein loss. Amen and Yoshumira have presented evidence which indicates that isoleucine, leucine, and valine are important for stimulating anabolic function in humans. Isoleucine is also converted in the liver to blood sugar; therefore, it can be helpful in maintaining proper blood glucose levels. Therapeutic doses of isoleucine range between 200 to 2,000 mg per day.