Train Harder with Glutamine
Table of Contents
| Glutamine Benefits for Athletes |
L-glutamine is the most abundant amino acid in the bloodstream and it makes up 30-35% of the amino acid nitrogen in your blood. L-glutamine can be found in animal proteins such as meats and dairy, along with plant based protein sources such as beans, raw spinach, parsley and red cabbage. Although, the plant proteins are not as easily digestible as the animal proteins. Skeletal muscle is the major tissue involved in glutamine synthesis and is known to release glutamine into the circulation. Its alleged effects can be classified as anabolic and immunostimulatory. The role of glutamine seems to be more relevant for endurance athletes than for resistance training athletes. Glutamine does not act as an ergogenic for increasing the number of repetitions that can be performed during resistance-training workouts. Chronic glutamine supplementation during periods of resistance training does not lead to greater gains in muscular strength and size in comparison with a placebo. For example, one recent study examined the effect of acute glutamine ingestion on weightlifting performance. This study examined the potential buffering effect of glutamine on lactic acid production during resistance exercise. One hour following glutamine ingestion (0.3g/kg), glycine ingestion (0.3g/kg), or placebo drink ingestion, the trained subjects performed 2 sets each of leg press (@ 200% body weight) and bench press (@ 100% body weight). This would equate to an average of ~23 grams of Glutamine. Each subject consumed one of the three supplements before three separate testing sessions separated by a week. There was no effect of glutamine on number of reps performed compared to glycine or placebo ingestion. These results indicate that a high dose of glutamine ingested before exercise has no positive or negative effects on weightlifting performance in trained subjects. Another study had trained subjects consume either 0.9g/kg lean body mass/day (average of 45 grams of glutamine per day), or a placebo, in 2 divided doses. By the end of the 6-week period, there were no differences in terms of 1Rep Max on squat or bench between the groups. There were also no differences between groups when it came to the gains in lean body mass (i.e. the amount of muscle they put on) during the trial period. This study was well designed and used the highest amount of glutamine ever studied for these purposes, but there were no reported benefits of glutamine for benefits in resistance exercise.
| Glutamine may be beneficial for extended periods of athletic performance involving high-accuracy activity. It may therefore be useful as a pre-competition supplement for endurance exercise. Periods of very heavy training are associated with a chronic reduction in plasma concentrations of glutamine and it has been suggested that this may be partly responsible for the immunodepression apparent in many endurance athletes. The effects of acute exercise on plasma glutamine concentration appear to be largely dependent on the duration and intensity of exercise. One of the major functions of glutamine is to regulate the immune system as its utilization at high rates by leukocytes (particularly lymphocytes) to provide energy and optimal conditions. Prolonged exercise is associated with a decrease in the intramuscular and plasma concentrations of glutamine and it has been hypothesized that this decrease in glutamine availability could impair immune function. The intramuscular concentration of glutamine is known to be related to the rate of net protein synthesis and there is also some evidence for a role for glutamine in promoting glycogen synthesis. However, the mechanisms underlying these alleged anabolic effects of glutamine remain to be elucidated. |
Glutamine and Prolonged Endurance Exercise
The glutamine hypothesis is that a decrease in plasma glutamine concentrations, brought about by heavy exercise and training, limits the availability of glutamine for cells of the immune system that require glutamine for energy and nucleotide biosynthesis. Thus, the glutamine hypothesis provides a mechanism to explain exercise-induced immune impairment and increased susceptibility to infection in endurance athletes. Serious long term endurance exercise can lead to a overtraining and respiratory infections and other negative consequences in which low glutamine may play a role. The resting plasma concentrations of glutamine have been reported to be lower in over-trained (chronically fatigued) athletes compared with healthy well-trained athletes and sedentary individuals. For example, 1 study reported values of 503 μmol/L for plasma glutamine in over-trained athletes compared with a concentration of 550 μmol/L for healthy control athletes (a 9% difference). A 23% reduction in resting plasma glutamine concentration has also been observed after 2 wk of intensified training in elite swimmers. Among chronically fatigued, elite athletes, resting plasma glutamine levels of 330–420 μmol/L have been reported; those suffering from an infection did not differ from those who were not .In contrast to the data for high intensity exercise, there is a consistent body of evidence showing that the plasma glutamine levels fall substantially after very prolonged exercise. Plasma glutamine concentration decreased from 557 μmol/L at rest to 470 μmol/L immediately after 3.75 h of cycling at 50% V̇O2 max. The plasma glutamine concentration reached a minimum of 391 μmol/L after 2 h of recovery and remained depressed at 482 μmol/L after 4.5 h of recovery. Large declines in plasma glutamine level following a marathon race from 592 μmol/L (prerace) to 495 μmol/L immediately postrace were reported in 24 club standard athletes. Thus Glutamine can have many benefits for the athlete performing steady state, long duration cardiovascular activities that can impair immune function and also result in overtraining.
 Dosaging for Glutamine: The recommended glutamine dose for weight trainers or power athletes should be 10 grams daily of L-glutamine powder taken before and after a workout. This is usually consumed within the servings of a protein shakes, as L-glutamine is often an active ingredient along with other amino acids. If you are looking to improve digestive health and heal leaky gut it is recommended you take 5 grams of glutamine powder 2x daily with meals. |
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