L-glutamine – bodybuilding and endurance benefits

By Kim Crawford, M.D. Last updated: May 8, 2019

L-glutamine for endurance and bodybuilding:

What is L-Glutamine?

kelzyme is good for muscles L-Glutamine is an amino acid produced in your body. It is the most common amino acid in your muscles, making up a whopping 61% of your skeletal tissue.

It isn’t one the “essential” amino acids, but it can become  essential in times of intense athletic training.

It can affect amino acid metabolism and nitrogen balance in your muscles.


Glutamine is important in a number of metabolic processes related to muscle recovery after any exercise. Because of this, it has been used as a nutritional supplement for bodybuilders and athletes seeking to gain muscle size and increased strength.

The Benefits Of L-Glutamine!

Glutamine is a carbon and nitrogen donor. It helps restore glycogen which restores energy. Glutamine is the most important component of muscle protein. It helps repair and build muscle. Here’s a list of glutamine benefits and then I’ll delve into details:Glutamine is closely linked to protein synthesis. It prevents your muscle from being catabolized (eaten up) in order to provide glutamine for other cells in the body.

Glutamine helps maintain cellular volume and hydration. It speeds up wound and burn healing.

Glutamine supplementation replenishes declining glutamine levels during intense workouts.

Research has shown Glutamine can help you produce growth hormone levels. A study has shown 2 grams of L-Glutamine increased human growth hormone  levels by over 400%.

However HGH is short lived and to really have an impact on human growth hormone levels you would need to supplement all day.

Since 40 grams is the absolute maximal dosage of l-glutamine you can take it would be possible with high doses to actually affect HGH levels. Otherwise, as real bodybuilders know…not.

Glutamine may serve to boost your immune system. For bodybuilders, this is important since heavy workouts tend to greatly deplete glutamine levels. (Glutamine is an important and even primary energy source for your immune system.)

Glutamine is one of the most important nutrients for your intestines. It has the ability to help “repair a leaky gut” and restore  perfect GI function by maintaining the structural integrity of the bowels.


L-glutamine Assists Muscle Growth

Research suggests that Glutamine is the most important amino acid for bodybuilders.

It provides a component in muscle metabolism and cellular support not shared by any other single amino acid.

The most common use of this supplement is for muscle growth by all athletes including bodybuilders.

Supplementing our diet when working out can greatly assist with protein synthesis.

When the body is depleted of this amino acid during intense workouts, actual cellular muscle wasting can occur.

This can cause tiredness and slower recovery periods.

Supplementation with l-glutamine allows the recovery period to be reduced enhancing the athlete’s strength program by helping to repair the muscles more quickly.


L-Glutamine in Muscle Repair for Bodybuilders:

Injured muscles need large amounts of glutamine to repair them. Bodybuilding is a series of micro-injured muscles which then repair and grow.

Growing muscles need glutamine to build new fibers to give the muscle greater strength and bulk. If you work out only occasionally you don’t need l-glutamine supplementation.

Bodybuilders are often “pushing to the limit” and don’t give their muscles the “full recovery time”.

If they did, even THEY likely wouldn’t need l-glutamine supplementation. But since the “nature of the sport” is such that recovery time is incomplete, they are considered in the group of people who exercise so often they don’t give their muscles time to recover. Hence, the recommendation to supplement for this population of athletes.

Especially the pros.


When there is not enough glutamine in the bloodstream to repair injured muscles, the body shifts glutamine from the production of white blood cells (the cells that fight infection) to injured muscle.

This is one of the principal reasons athletes involved in intense competitions or training tend to get colds and flu.

Over-training syndrome is a condition that results from exercising more intensely and frequently than your body is capable of handling.

It is associated with fatigue, and phrases such as “I need help falling asleep” and “I can’t stay asleep” are commonly heard by doctors like myself.

Of course over-training causes decreased muscle strength but a “strange” often initial tell-tale sign is an increased heart rate.

Bodybuilders may be more susceptible to over-training than other athletes.

Glutamine supplementation may reduce the effects of over-training syndrome by increasing the rate of muscle recovery following exercise due to an increase in the rate of protein synthesis in your muscles.

And role in repair for Non-bodybuilders:

Role in weight control:

Extremely obese persons who are both exercising and following a diet may experience many metabolic changes.

Their bodies experience the same changes in their muscles after moderate exercise (even walking around the block sometimes) as fit persons experience in extreme sports.

Glutamine may be helpful for them to gain metabolism boosting muscle if they adhere to anti inflammatory diets, and eat foods that give you energy as well as foods that speed up metabolism. That includes nutritional ketosis diet plans as well.

Obviously, supplements, too.

Role in endurance performance:

If you are involved in high-intensity extreme sports, then glutamine supplementation is for you too.

Cross-country bike races, cross-country running, marathons, biathlons, triathlons, long distance cross-country skiing  and high-altitude sports can cause extreme muscle breakdown.

People who climb Mt. Everest, for example, suffer muscle weakness for months or even years after the event.

It has long been suggested that these individuals will regain energy faster if they were to supplement with l-glutamine amongst other things.

L-glutamine helps with cellular hydration:

When you undergo intense and strenuous physical exercise, your cells become deprived of water.

By taking l- glutamine supplements, your cells stay more hydrated, thereby, reducing the time required to recover from any sort of  injury.

In the sport of bodybuilding injury is thought of as the tearing down and building up of muscle tissue.

But you can have a muscle tear, ligament tear or small sprains in the course of intense  exercise. The supplement helps in reducing the effects of the stresses and strains on your body but making your cells stay more hydrated and malleable.

Energy Production

Glutamine has the ability to create muscle glycogen from blood glucose, which increases energy availability and  production during exercise.

Increasing the availability of glucose to your skeletal muscles during exercise may increase exercise performance, intensity, and recovery.

L-glutamine also assists in the removal of amino acids, pyruvate, lactic acid and other byproducts of energy metabolism in your muscles, thereby shortening your recovery time between exercise sets.

L-Glutamine as an “Alkalizer”

The kidneys use glutamine to keep the pH of the bloodstream almost constant by transforming glutamate into glutamine and then back again.

When there is not enough glutamine or glutamate, the kidneys can also use calcium from bone.

That is the reason “acidifying” diets are associated with osteoporosis and therefore not good for you.

The body transforms glutamine into glutamate when it needs to alkalinize the blood by removing ammonia from the blood.

This process requires an enzyme called glutaminase.

This enzyme transforms glutamine into glutamate in the kidneys so they can excrete ammonia.

This action detoxifies the blood and normalizes the pH by removing excess ammonia which is an acid waste product from the body’s use of amino acids.

The kidneys just have to manage these two amino acids to keep the blood at the right pH with tolerable levels of ammonia released as the body uses amino acids to make proteins.

Glutamine requires the least energy of all the amino acids that could be used for this purpose.

Gastrointestinal health:

Our intestines (believe it or not) use the maximum amount of glutamine in the body.

Glutamine is often recommended for those with  diverticulitis and research shows it has a role in the healing of ulcers and a truly major role in healing leaky gut.

We know it helps maintain the intestinal lining. We also know that under conditions of intense training, bloodflow to the gut is “cut off” for the most part.

Bodybuilders report improved GI functioning as yet another benefit of l-glutamine supplementation.

How Much L-glutamine do you need?

Bodybuilders should ingest 10 to 15 grams of L-Glutamine per day – supplementing it 2 to 3 times daily, with each serving at around 2 grams during normal training and 4 grams pre-contest.

You should also know that you may already be getting some L-Glutamine in your diet from other supplements you’re taking.

Many protein supplements already have some L-Glutamine mixed into it, so read the labels to know for sure.

The optimal times to take L-Glutamine is in the morning, after a workout, and at night before bed time.

I personally recommend some L-glutamine prior to a work-out and our newly reformulated branched chain amino acids product, BCAA’s and l-glutamine  contains L-glutamine and should be taken pre-work-out… so that covers that! Note that if you have leaky gut- you can put the powdered form of l-glutamine in your “leaky gut” drink and I recommend a heaping tsp 2x/day.


1 Comment

  1. I need to add L-Glutamine to my daily supplements. I go to the gym six days a week and I know I’m not allowing my muscles the chance to recover from my daily workouts. I have also noticed lately that I can not fall asleep like I use to.
    Thank you for the information, I will definitely be purchasing this!

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