Glutamine is one of the body's most abundant amino acids, and is an amino acid known as, “conditionally essential.” This means that while the body is capable of producing it under normal physiological conditions, it may require additional dietary sources under certain conditions such as athletic training or stress. In these conditions, glutamine takes on a critical role in the metabolism of muscular protein, in the volumization of cells, and the reduction of cell catabolism (particularly in stressful or traumatic situations). Glutamine has additionally been demonstrated to be immunoprotective in stressful situations, meaning that supplementation with glutamine may help to maintain immune system function.