Glutamine (L-glutamine), derived from glutamic acid (glutamate), stands out as the most abundant free amino acid in the body, both intracellularly and extracellularly, as it corresponds to more than half of all the amino acids in cells, making it a precursor to multiple proteins.
It is a non-essential amino acid, which under certain circumstances is essential, which is why it is generally classified as essential with conditions.
The main source of glutamine is found in skeletal muscle, although the lung and brain also contribute to its production. Under normal conditions, the cells of the immune system are one of the main captors; however, in intensive exercise situations, the needs for L-glutamine increase, surpassing the body’s ability to synthesize it from its endogenous sources; therefore, if it is not supplied in sufficient quantities from the diet, the organism increases the catabolism of the tissues, especially the muscle, which increases the release of glutamine into the blood by 3 to 4 times to satisfy the demands of other organs. like the intestine, liver, kidneys and especially the immune system; so skeletal muscle is forced to synthesize and export more glutamine than usual.
L-glutamine helps decrease the use of proteins as an energy source and favors the use of carbohydrates (glucose), which means that, to perform this function, instead of the body using energy from proteins (especially muscle) and these are depleted or worn out, use that of glucose.
During high intensity or resistance exercise, the glutamine concentration decreases significantly up to 20% or more, but it usually recovers after 24 hours. When needs increase, supplementing the diet with L-Glutamine is beneficial, to promote the maintenance or gain of muscle mass, the efficiency of muscle recovery processes, improves muscle glycogen recharges and proper organic function.