Many people are surprised to discover that glutamine is the most abundant amino acid present in the human body. More than 70% of amino acid content found in muscle cells comprises of glutamine, and it is in fact present in virtually every single animal-based food you consume.
Under normal circumstances, the body is able to produce enough of the glutamate required to maintain vital processes, making this amino acid semi-essential at best. However, athletes are not considered normal members of the population by any stretch of the imagination, so it should come as no surprise that increased levels of physical activity mandates more of this amino acid.
Supports Proper Nutrient Uptake
In order for muscles to directly benefit from the many nutrients you supply, absorption of these must be on point. For most people, this is taken for granted as they just assume that whatever they consume is automatically shuttled to muscle.
However, in reality this is far from the case, as a not-insignificant proportion of adults suffer from digestive disorders of one form or the other. One of the most noteworthy is leaky gut syndrome, which can lead to a cycle of impaired absorption, otherwise known as malabsorption.
Supplementation of glutamine can help reduce the impact of leaky gut syndrome on your nutritional status, since glutamine forms an integral part of the structural cell wall linings along the digestive tract. Greater structural integrity means reduced permeability[ii] that would allow nutrients to leak out of the digestive tract.
Helps Preserve Muscle Mass In Sedentary Individuals
Starting an exercise program if you’ve never been part of one before induces acute metabolic changes that include severe muscle loss. Indeed, after a brief adaptation period the status quo is changed, but initially you can lose much more than you are gaining.
This is in large part due to glutamine catabolism to help fuel the intensity of the work that you are now getting accustomed to. This effect is even more significant in obese people that are also on a calorie restricted diet. This is another reason why muscle loss is to be carefully monitored on a calorie restricted diet.
Promotes Recovery After Endurance Activity
Bodybuilders and strength athletes aren’t known for performing endurance type activities very often, but if you are a marathon runner or a triathlete, then you’re very likely to experience extreme muscle breakdown during, and especially the weeks to months after the activity. Yes, you read that correctly. Accelerated rate of muscle loss may continue unabated for an extended period of time after the activity, which is also why such athletes are more prone to injuries than others.
Supplementation of glutamine before, during, and especially after such activities can mitigate the degree of muscle loss experienced.
Supports Muscle Protein Synthesis
It is important to state that glutamine itself does not have a major role on muscle protein synthesis, but at the same time, any acute stressor that reduces the net amount of glutamine in the body will impair the same.
Studies have shown that consuming glutamine post workout can support optimal protein synthesis, so that cells of the immune system which would have become stimulated; especially those found in the intestines, do not leech necessary glutamine from muscle cells for recovery.
Stimulates Growth Hormone Synthesis
While glutamine itself is not considered a very potent anabolic amino acid, it does have a very exciting benefit by virtue of enhancing the amount of circulating growth hormone[iii]. To take advantage of this benefit, glutamine needs to be taken on an empty stomach.
This makes before bed ideal. A 2 g serving taken at this time can support muscle growth and the usage of fat for fuel while you sleep, since this also coincides with the period of time at which growth hormone levels are the highest.
Supports Cell Volumization
Volumization is a poorly understood principle by athletes, but one that has significant implications. To put it simply, it refers to the level of muscle hydration, and is achieved by ensuring adequate fluid and electrolyte balance during your workout.
You may have heard that even very mild dehydration can impair athletic performance to an exponential degree, but what you may not have heard is that a little bit of supplemental glutamine can help to suppress the effect of mild dehydration on the body[iv], especially when using in conjunction with a beverage containing glucose and other electrolytes.
This makes such a combination a smart intra-workout beverage, one that will help keep performance up so you can complete what you set out to do.
By itself, glutamine may seem insignificant. However, its potential benefits are amplified many times over when combined with other well-timed nutrients/supplements. For instance, a combination of glutamine and BCAAs increase mTOR signalling that has a net effect of enhancing protein synthesis.
Combined with creatine, it can also help enhance its ability to increase strength and muscle size fast, since creatine requires a high degree of muscle cell hydration to work best. Glutamine help support this state, leading to more rapid increases in the gym than you would experience from using creatine alone.
Even though glutamine is technically semi essential, you can see how it can rise to the status of being essential in athletes. Yes, it will not lead to significant steroid like gains, but when you’ve been training for a number of years every little bit counts.
Also, of note is the fact that athletes who train less frequently may experience greater benefits from glutamine supplementation since the degree of muscle damage is greater per training interval. You don’t need to go bonkers with glutamine supplementation; if you decide to take 5 g three times daily that would be more than sufficient to top up muscle stores and ensure that all other cells which require it are well taken care of.
[i] Demling RH. Nutrition, anabolism, and the wound healing process: an overview. Eplasty. 2009;9:e9.
[ii] Rao R, Samak G. Role of Glutamine in Protection of Intestinal Epithelial Tight Junctions. J Epithel Biol Pharmacol. 2012;5(Suppl 1-M7):47–54. doi:10.2174/1875044301205010047
[iv] Coqueiro AY, Rogero MM, Tirapegui J. Glutamine as an Anti-Fatigue Amino Acid in Sports Nutrition. Nutrients. 2019;11(4):863. Published 2019 Apr 17. doi:10.3390/nu11040863