Unlike many dietary supplements that offer one kind of support to the body, glutamine offers several benefits. Glutamine is an important amino acid that contributes to almost all body structures as well as to energy generation. Over 60% of all free-floating amino acid in our muscle tissue is composed of L-glutamine. Our bodies usually produce enough glutamine for our needs, but during times of added stress, glutamine production may not be sufficient and our immune system can become depressed. When this happens, we need to find ways to get glutamine through our diet.
Exercise is considered a stress to the body. Regular exercise combined with life's usual stresses (financial, work-related, sleep deprivation, etc) can result in immune system suppression due to insufficient glutamine production - and as we all know, getting sick can easily throw us off the track of our fitness program and goals. A lack of glutamine can also result in decreases in strength, stamina, and recovery. Endurance athletes can be particularly prone to deficiencies in glutamine, but even strength athletes need to be careful that they help their bodies recover properly from exercise stress.
Glutamine is used as an energy source in the gastrointestinal tract, which is the greatest consumer of glutamine in the body. Glutamine supports the GI tract lining and may prevent toxins from entering the bloodstream through this route. Some evidence points to the idea that diseases such as ulcerative colitis and Crohn's disease may be related to glutamine deficiencies, but more research is needed on the benefits of taking glutamine supplements to relieve these conditions. Glutamine is also used as an aid in healing after surgical procedures. Research has shown that recovery times after abdominal surgery are reduced by taking glutamine supplements, and that post-operative patients who take glutamine have better amino acid profiles than those who do not. Glutamine has not been shown to have any side effects.
Frequent exercisers may not be able to recover their glutamine levels between exercise sessions, and they may notice they have higher frequencies of colds or allergies. High-intensity or anaerobic exercise particularly depletes glutamine. Since muscle tissue supplies the most glutamine in the body, it is important to allow muscles to recover between exercise sessions or supplement the diet with glutamine. Glutamine aids in weight loss while retaining muscle tissue. Glutamine can also help the body recover glycogen levels between exercise sessions.
Dietary glutamine can be found in beans, beef, pork, poultry, milk, yoghurt, ricotta cheese, cottage cheese, raw spinach, raw parsley, and cabbage. Another good source is whey protein. Most people get about 3.5 to 7 grams of glutamine per day in their regular diet. For people who do not exercise, this amount is usually sufficient and supplementation may not provide any noticeable benefits. However, for regular exercises, a supplement of 2 to 5 grams per day (after prolonged exercise sessions) may give you excellent results. Strength athletes such as bodybuilders and endurance athletes may take up to 10 grams per day. Higher amounts have not been shown to provide additional benefits to generally healthy individuals. The research on the effectiveness of glutamine supplementation is somewhat controversial - there are studies that show that supplements do indeed restore depleted glutamine levels, and studies that do not show any change. However, glutamine supplements are relatively inexpensive and have not been show to do any harm or have any side effects. Therefore it is safe and you can try supplementation to see what kind of results you get.