L-Isoleucine is an essential alpha-amino acid that is considered both, a ketogenic and a glucogenic amino acid. Since that L-Isoleucine is an essential amino acid, it cannot be synthesized by the body, therefore it needs to be ingested. The primary source of L-Isoleucine is as a component of proteins. It has become a prominent component of nutritional supplements, mostly with the body building and similar athletic communities, where it is believed that L-Isoleucine has the capability to increase endurance, but also to repair muscle tissue. It has been observed that L-Isoleucine ingestion allows power athletes to recover easier from very tough trainings and exhausting activities. This branched chain amino acid is one of the three main BCAA in the body, the other ones being valine and leucine.

L-Leucine is useful in conjunction with L-Valine and L-Isoleucine as an amino acid supplement. L-Leucine is an amino acid that a body cannot produce on its own. It is expected to be received externally from food sources such as brown rice and nuts or even through some of the dietary supplementation. L-Leucine is showing numerous advantages in the athletic qualities. Within six week of training with L-Leucine in association, a person is able to maximize the aerobic power. In the six weeks the strength and power in the upper body increases. However, research and studies is limited carried on the athletic performance. L-Leucine incorporated into the muscle protein in continuation with two weeks exercise regime will give adequate resistance and the muscle protein synthesis will certainly show an increase. L-Leucine is a preservative of the muscles, but is as well a supplement that enhances the capabilities of muscle building owing to the enhanced protein synthesis rate.

L-Valine is the third branched chain amino acid and is required for muscle metabolism, repairs and regenerates tissue, and maintains the body's nitrogen level. It also is used as a muscle energy source and preserves the use of glucose.