L-Glutamine is a naturally occurring amino acid and one of the most abundant amino acids in the body (comprising approximately 30% of amino acids in the plasma).
It is usually classified as a conditionally essential amino acid as it is produced by the body, but during periods of extreme stress or trauma it is released from the body and needs to be replenished.
Glutamine is naturally found in beans, poultry, fish and dairy products. The majority of Glutamine is produced in the skeletal muscle and adipose tissue. Additionally, glutamine is synthesized in the lungs, liver and brain. It is predominately used for fuel by the small intestines, immune system, hair follicles and the gastrointestinal tract.
Glutamine has been found to help mental activities such as concentration and memory associated with the brain. Glutamine reduces lactic acid levels by regulating the acid-base balance in the body. Glutamine also promotes cell volumization, supports the immune system, increases nitrogen retention and stimulates the entry for other amino acids into the cells.
Traditional Use of Glutamine
Glutamine was initially used in the hospital setting to provide support for burn patients and those who had undergone severe trauma. During illness, plasma levels of glutamine are diminished which leads to a suppressed immune system. Glutamine has been found to help enhance stress protein response, improve metabolism of tissues and provide nutrients to enhance recovery. The body requires more glutamine than it can produce during stress or trauma.
Glutamine and Exercise
Building solid muscle takes a lot of hard work and dedication. By not replenishing muscle fuels and getting adequate amounts of rest, the body will become catabolic (muscle tissue will break down). Research has shown low levels of glutamine in the body are associated with muscle loss.
Glutamine ensures the body remains in a state of anabolism. For those who train, supplementing with glutamine ensures the body’s stores of this important amino acid are optimized and skeletal muscle size is maintained. Working out can lead to suppression of the immune system. Intense exercise can quickly deplete glutamine in the muscle cells causing the immune system to weaken and decreases the body’s levels of glutamine. Research has shown that supplementation with glutamine can alleviate the decline of glutamine concentration in the bloodstream following intense exercise.
Glutamine also helps to diminish catabolism caused by an increase in the stress hormone cortisol, which is elevated during exercise. A recent study conducted on glutamine’s effects on the muscle found that glutamine actually blocks the action of cortisol’s interference with muscle protein synthesis and repair. This study shows that glutamine can provide an anti-catabolic effect which is beneficial for athletes and bodybuilders.
Glutamine supplementation has been found to help elevate glutamine levels in the body and produce an anti-catabolic effect. It can minimize the amount of muscle breakdown and can be particularly helpful when consumed after working out; when catabolism is at its peak.
Glutamine for Immune Support
Glutamine supports healthy immune function. Stress to the body such as burns, surgery, overtraining or intense exercise can cause a reduction in plasma levels of glutamine. During illness, glutamine metabolism is increased for antibody production and protein synthesis. The body demands an increase in dietary sources of glutamine when the immune system is suppressed to replenish the stores. Research conducted on glutamine supplementation on athletes has found that it is an important amino acid to elevate the immune system, which is often suppressed in athletes.
Glutamine for Dieters
During dieting when calories and/or carbs are eliminated, glutamine supplementation can also be extremely helpful. The body’s level of glutamine can be diminished and as the body goes through stress, which is often associated with dieting, glutamine can help to maintain lean muscle mass and prevent the body from breaking down.
Glutamine Speeds up Recovery
Glutamine provides the nutrients needed to speed up recovery between workouts. This will allow training at an increased intensity and prevent down time. It can also help to elevate the immune system and prevent the body from becoming run-down. High intensity exercise suppresses the immune system and this can be prevented by supplementing with glutamine.
How to Take Glutamine
Glutamine comes in a tasteless powder form that easily dissolves in liquid. It can be combined with water or mixed in a protein shake. There are two critical times glutamine should be consumed:
- Post Workout – after working out, glutamine levels are diminished. Supplementing with 5 grams of glutamine immediately after working out will ensure glutamine levels are restored.
- Immediately before bed –consume 5 grams of glutamine before bed to ensure the body remains in a state of anabolism during sleep and muscle isn’t broken down.
Glutamine Side Effects and Deficiency
Very few side effects are associated with glutamine. Studies conducted on the short and long-term effects of glutamine supplementation at doses from 0.1 to 0.3 g/kg of body weight found no side effects or toxicity.5 Thus, glutamine supplementation has been confirmed to be relatively safe for normal individuals. However, extremely high amounts of glutamine may be harmful for those with liver or kidney problems.
Glutamine is an extremely beneficial supplement for athletes and bodybuilders. It can help preserve lean muscle mass, keep the immune system elevated and prevent the negative effects associated with overtraining.
- Antonio, J. & Street, C., (1999).Glutamine: A potentially Useful Supplement for Athletes. Can J. Appl. Physiol. 24(1); 1-14.
- Kreider RB (1998). Central fatigue hypothesis and overtraining. Overtraining in Sport (pages 309-31). Champaign, Illinois: Human Kinetics.
- Salehian, B., et al (2006). The Effect of Glutamine on prevention of glucocorticoid-induced skeletal muscle atrophy is associated with myostatin expression. Metabolism, 55: 1239-47.
- Richard B Kreider PhD. Effects of protein and Amino Acid Supplementation on Athletic Performance. sportsci.org 5. Tjader. I.,et al (2007). Exogenous Glutamine – Compensating a shortage? Crit Care Med, Vol:35, No.9: S553-S556.