Studies of hospital patients show that glutamine is useful for countering the catabolic state that leads to loss of lean tissue, mainly muscle. Although glutamine is synthesized in the body from other amino acids, such as the branched-chain aminos, sick people may not be able to produce enough glutamine, so it makes sense to give them the amino acid.The picture isn’t as clear with healthy, young, active people. Some studies show that glutamine may offset some aspects of overtraining. Specifically, overtraining leads to a blunting of immune response, which predisposes people to getting sick if they’re exposed to disease-causing organisms. Since some immune cells use glutamine as a primary fuel source, glutamine may improve immune response by providing energy to immune cells.
Still, glutamine’s true effect on those who exercise is subject to debate. Research presented last year at a meeting of the American College of Sports Medicine examined whether it aids exercise recovery.1 Twelve men, aged 19 to 30, engaged in cycling routines with varying intensity levels during the six-day study. One group received a carbohydrate drink that contained 0.3 grams of L-glutamine per kilogram of bodyweight, while the other group got a straight carbohydrate drink.
Those drinking the glutamine withstood exhaustion significantly longer than those who drank the carb-only beverage. The authors suggest that glutamine does indeed appear to aid recovery from exhaustive exercise.
1 Piattoly, T., et al. (2004). L-glutamine supplementation: effects on recovery from exercise. Med Sci Sports Exerc. 36:(Supp)S127.
