Taking a glutamine supplement will help your body replace the most abundant amino acid in your body. Replacement is needed due to depletion resulting from intense exercise, illness, personal stress and lack of sleep. Really, any situation where your body is not "in a happy place" can lead to glutamine deficiency.
Let's take a look at what a glutamine supplement can do for our body.
L-glutamine is the most abundant amino acid in our bodies. It is primarily stored in the muscle tissue. When our bodies are put under stress due to illness, intense physical activity (like you are going through) & mental stress from work or personal challenges the stored glutamine is released to the digestive system to maintain balance there and allow proper nutritional absorption to fuel your body (1).
When your body is not in it's steady-state, glutamine is one of the first amino acids it looks for as fuel to keep going. Here is a sample of what it does for the body.
Muscle Growth & Recovery
When we are under stress, the body releases cortisol (the stress hormone). This puts the body in a catabolic state (muscle and other tissues are broken down) as opposed to an anabolic state (muscles are being built up). Adding glutamine immediately after an intense workout helps improve glycogen synthesis in the body thereby reducing recovery time (2,3). Faster recovery helps your next workout be more effective, burning more fat and building more muscle.
Weight Loss Support
This benefit is particularly important to readers of this site. It's why you are here, right? A study of glutamine use among over-weight women showed a significant decrease in body weight and waist size among the study's participants (4). Even though this study was on women, there is little doubt that it will have a similar impact on men.
Immune System Support
I mentioned, above, that when we are ill, our glutamine supplies are depleted. The glutamine stores tend to stay low for and extended period of time, too. This will have a negative impact on your recovery from illness let alone the effectiveness of any exercise you undertake while ill. The results of a study show that supplementation of glutamine alone and with a carbohydrate during exercise found increased glutamine levels in the bloodstream. More glutamine means quicker recovery.
There are two primary sources for manufacturing l-glutamine. Most commonly it is chemically synthesized in a lab. You can also get L-Glutamine that has been fermented from vegetables. It is usually more expensive and there are fewer available suppliers, but it is a better, more pure product in my opinion.
Glutamine is available from a variety of manufacturers at any sports nutrition store. You will save a money by purchasing it online, however. Just plan ahead to make sure you don't run out. Just as an aside, glutamine and its precursor glutamic acid is often included in meal replacement powders. Pure glutamine is a better supplement. However, if your budget is a bit tight, pick an MRP that contains glutamine.