Of all the amino acids that can be taken separately, none come close to generating the potential of L-glutamine. (Don’t let the “L” confuse you – many molecules exist in two forms that are mirror images of one another. Chemists use “L” and “R” to denote left- or right-hand orientation.) L-glutamine is classified as a “semi-essential” or “conditionally essential” amino acid. Under normal circumstances the body can synthesize sufficient L-glutamine from other amino acids to meet physiological demands, but under some conditions the body cannot do so. Recently, L-glutamine has come to be regarded as one of the most important of the amino acids when the body is subjected to stress such as trauma (including surgical trauma), cancer, burns and … intense exercise! Under these conditions, L-glutamine becomes an essential amino acid, and it is therefore very important to consume sufficient amounts to meet the increased physiological demands created by these situations.
L-glutamine is primarily synthesized and stored in skeletal muscle. A closely related amino acid, L-glutamate, is converted to L-glutamine in a reaction catalyzed by the enzyme glutamine synthase. This reaction requires ammonia, ATP and magnesium.
L-glutamine is a very versatile amino acid and participates in many reactions in the body. It is important in the regulation of acid-base balance and allows the kidneys to excrete high acid urine, thus protecting the body against acidosis. For bodybuilders, glutamine’s primary benefit is to keep the body in positive nitrogen balance, as discussed earlier. One simple way to determine if the body is in a state of negative nitrogen balance is to use your nose. Yes that’s right, take a good sniff! If the body is breaking down muscle tissue to be used as a fuel source, one of the byproducts is ammonia. There is no mistaking the smell of ammonia. Next time you see a triathlete or marathon runner at the gym, just keep your nose open as you walk by. Chances are you’ll detect the distinct smell of ammonia in their sweat. You’ll even smell it near pre-contest bodybuilders, as they are often in a catabolic, muscle-wasting state.
Bodybuilder or not, everyone wants to remain healthy, and besides being a necessity in muscle building, glutamine is also a primary ingredient in many of the immune system’s potent germ fighters. Such immune-system cells as monocytes, lymphocytes, and neutrophils are enhanced with glutamine supplementation. As long periods of intense exercise can depress the immune system, athletes would be wise to supplement with glutamine. The fact that the amino acid also boosts muscle-tissue synthesis is a bonus. The normal dosage of glutamine taken by bodybuilders and other athletes is 5 to 10 grams per day. As with creatine supplementation, it makes more sense to take smaller amounts more frequently.