L-Glutamine FAQ

1. What is it and where does it come from?

The extremely popular amino acid L-Glutamine can be found in protein powders, beans, meats, fish, poultry, dairy products, and of course, L-Glutamine supplements from Bodybuilding.com.

2. What does it do and what scientific studies give evidence to support this?

Glutamine is highly in demand throughout the body. It is used in the gut and immune system extensively to maintain optimal performance. 60% of free-form amino acids floating in skeletal muscles is L-glutamine. L-glutamine plays a very important role in protein metabolism, and it appears to be a very important nutrient for body builders. When supplemented, it may help body builders reduce the amount of muscle deterioration that occurs because other tissues that need glutamine will not rob the glutamine stored in the muscle cells.

Research shows that after intensely working out, glutamine levels in the body are reduced by as much as 50%. Since the body relies on glutamine as cellular fuel for the immune system, scientific studies have shown that glutamine supplementation can minimize the breakdown of muscle tissue and improve protein metabolism. Its effects on replenishing the body after stress or trauma have been shown in Europe where it is commonly given to patients in hospitals. Glutamine's cell-volumizing effects have also been shown in several studies. No conclusive studies have been done to evaluate the effects of L-glutamine supplementation on weight-training adults; however, a recent study showed up to a 400% increase in growth-hormone levels when as little as 2 grams of free-form L-glutamine supplement was consumed!

3. Who needs it and what are some symptoms of deficiency?

Bodybuilders can particularly gain from the intake of glutamine. Since bodybuilders use a lot of their glutamine when working out, they are more susceptible to health related problems, as the immune system relies heavily on this amino acid.

Catabolism or muscle break down can occur if the body robs muscles of glutamine for use elsewhere such as nitrogen transport or maintaining the immune system. Glutamine supplementation is certainly important in keeping muscles building--not deteriorating.

4. How much should be taken? Are there any side effects?

Bodybuilders can benefit by taking ten grams of L-glutamine per day, although clinical studies have not determined a precise amount for muscle metabolism optimization.

There are no side effects associated with L-glutamine, because it is a nutrient naturally occurring in the body. Reports of an upset stomach are associated with ingesting a great deal of glutamine, using smaller doses is recommended if this occurs.

Preserve Lean Muscle Mass with Glutamine

Preserve Lean Muscle Mass with Glutamine

What Is L-Glutamine?
L-Glutamine the most abundant amino acid in muscle cells. It is released from the muscle during times of stress (such as hard weight training workouts) and dieting. This amino acid not only has been shown to be a great anti-catabolic agent (protects the muscle from the catabolic activities of the hormone cortisol), to be a contributor to muscle cell volume, and to have immune system enhancing properties but also to help in the following ways:

• Regulation of protein synthesis (this is one of the ways in which steroids exert their muscle building effects).
• Accelerating glycogen synthesis after a workout.
• Sparing the use of the glycogen stored in the muscle cell (recall that the glycogen stored in the muscle cell is what gives the cell the healthy volume and firmness that you seek).
• Faster recuperation from weight training workouts.

How To Use It
Due to its anti-catabolic properties and the fact that it accelerates glycogen synthesis after a workout, glutamine is best taken 20-30 minutes after a workout with a protein shake. On days that you don't workout, just take it with your last protein shake of the day. While there is much debate amongst experts as far as dosage is concerned, I always like to remain on the conservative side. Therefore, I feel that 3-5 grams is a sufficient dosage to start with and as your stomach gets used to it you can increase it to as much as 10-15 grams.

As far as cycling this supplement, there is no evidence that suggests cycling would improve its efficacy.

Side Effects
As far as side effects we only experienced a slight stomach discomfort during the first week of use (I took the straight powder form). Other than that, I did not experience any other side effects and I have not found any literature that links its use to anything bad.

As usual, I recommend that you start with a low dosage (such as only 3 grams a day) in order to assess your tolerance. From there you can build up to 10-15 grams split in 2-3 servings per day (1 in the morning, 1 after the workout and another one before bed). I would reserve the highest dosage schedule for periods of extremely hard training such as pre-contest training.

By looking at the effects that this supplement can provide you with, along with the fact that these days it can be purchased for a very cheap price, we wonder why more athletes don't use it. This is especially important during dieting, as a way to protect the muscle from being cannibalized by the effects of cortisol.

Good Brands
On a final note, please remember that like any supplement you need to stick to high quality brands.

Good brands of Glutamine that I have used are:

• Prolab
• EAS
• Champion Nutrition
• Beverly International
• Met-Rx
• Labrada

Glutamine Guide

You are probably reading this guide because you are wondering if glutamine will work for you. If it will be of any benefit to you. So really you have a problem that needs a solution. The goal of this guide will be to determine, based on the results you are seeking, if your money will be best spent on glutamine or on another product. So first you need to know what results you are seeking from possibly taking glutamine. What do you want from it? Once you have that in your head, we must answer the following question...

What will glutamine do for you?

There’s nothing fancy about glutamine. It’s not a miracle supplement (there's no such thing) and using it won’t bring results overnight (again, no such thing). With that said, it really is a tremendous supplement with one major benefit that we all need. It's this: glutamine will help maintain your muscle. Glutamine prevents your muscle from being eaten away by catabolic effects. You don't have to persuade anyone that to preserve the muscle you've worked so hard to acquire is a big deal. First you acquire, then you preserve. Two very important factors. Next question we have is...

Does science support glutamine?

In all my product guides I've been completely honest and I've built up a level of trust with many you that I don't take for granted. For me it's easy... glutamine works. And I know many of you would take my word on that. But there is science to back it up. Let's start at the beginning. Glutamine is the most abundant amino acid found in muscle tissue. Studies have shown glutamine supplementation can prevent up to 70% of the muscle lost as the result of cortisol in the body (American Journal of Physiology 33:E 912-E917, 1996). Cortisol, as some of you may know, is a catabolic hormone that is often responsible for muscle tissue breakdown. Catabolic is in many ways the opposite of anabolic. Something that is anabolic helps build muscle tissue; something that's catabolic breaks down muscle tissue. Cortisol is catabolic. So it's important for people interested in developing and maintaining muscle mass to keep their cortisol levels in check. That's where glutamine comes in. So the final question to ask is...

Which brand of glutamine should you use?

With over twenty different choices, which one should you go with? Really, they are all the same. Every manufacturer gets their raw product from the same few factories. It’s a level playing field. Then it’s up to the marketing folks to try and convince us of the benefit of their product over the others. I think the question of which product to buy is an economical one. That is, which product will 1) last the longest and 2) be the least expensive per serving.

Check out the comparison chart below of the top five glutamine brands:

Top Five Brands Size Cost Servings Cost Per Serving IST Pure Glutamine 500 grams $24.95 100 $0.25 Optimum Nutrition 300 grams $17.99 67 $0.27 Prolab Glutamine 400 grams $18.00 90 $0.20 Beverly Glutamine Select 552 grams $37.00 60 $0.62 AST GL3 600 grams $29.97 60 $0.50