A glutamine guide

Some describe it as a basic supplement that no bodybuilding supplement plan should be without, whereas others say that it does not live up to its hype. This article will therefore take a closer look at the benefits glutamine can actually have for the user.

In the diet, glutamine is found in virtually all animal products and makes up on average over 5% of the amino acids found in animal protein sources such as meat, dairy products and eggs.

Glutamine is the most abundant amino acid in the body, found not only in muscle tissue but virtually everywhere in the body, and plays a myriad of important roles in all sorts of processes in the body. Glutamine is something like the "Jack of all trades" among amino acids.

Intuitively, you would probably think that an amino acid that is so important must be an essential amino acid. However, this is not the case, as the term essential amino acid only refers to amino acids that the body cannot produce itself. However, the body can synthesize glutamine when needed, which is why glutamine is technically only a conditionally essential amino acid. Conditionally essential means that under normal circumstances the body can produce enough glutamine to meet its needs. However, there are situations in which the glutamine requirement is so high that the body's own glutamine production is not sufficient to cover this requirement. In such situations, additional glutamine must be supplied through food.

Glutamine has many supporters as a supplement. However, there are also many skeptics who say that glutamine supplementation is useless unless you are a burn victim recovering from your burns. Below we will look at some of the properties of glutamine and scientific research to help the reader decide whether or not they should supplement with glutamine.

What functions does glutamine have in the body?

Glutamine is formed in the body when the non-essential amino acid glutamic acid is broken down and combines with nitrogenous ammonia molecules. Glutamine can be thought of as a kind of nitrogen sponge that absorbs ammonia and transports nitrogen back and forth between different types of tissue, where it can be used for cell growth, tissue repair and many other functions. It has been calculated that between 30 and 50% of all nitrogen produced by the breakdown of protein is transported in the form of glutamine. In addition to this, glutamine can also be broken down back into glutamic acid, making glutamine a crucial source of ammonia and nitrogen in the body.

About 70% of the glutamine present in the body is produced in skeletal muscle, from where it is transported to the small intestine, kidneys and white blood cells. These are the dominant locations where glutamine is used.

The internal levels of this amino acid vary depending on different factors. Pregnancy and lactation deplete glutamine stores, as do exhaustive exercise, illness, starvation or fasting, rapid growth and development, and states of extreme physiological stress. These are some circumstances where an increase in glutamine intake or the use of a glutamine supplement would be appropriate.

Glutamine is also involved in the regulation of protein synthesis and degradation like no other amino acid. But there is more. Glutamine significantly influences BCAA metabolism, maintenance of the intestinal wall barrier, normal immune function, glucose formation, water transport, nerve impulse transmission and much more.

The kidneys are the primary consumers of glutamine. In the kidneys, ammonia is split off from glutamine to maintain the acid-base balance. Wherever you find ammonia in the body, you will also find glutamine. When metabolic acidosis (acidosis) increases, for example in response to intensive training or a high-protein diet, the uptake of glutamine by the kidneys increases sharply. For example, one study showed that just four days of a high protein and high fat diet was enough to cause a 25% reduction in plasma and muscle glutamine levels.

When consumption from all these competing glutamine uses begins to exceed the body's ability to produce glutamine, symptoms of glutamine deficiency can become apparent, including muscle breakdown, lack of energy and increased susceptibility to infection.

What are the uses of glutamine in sports?

Despite the many different functions of glutamine, there is little evidence that the use of glutamine in normal, healthy people directly results in an increase in muscle mass, a reduction in body fat or gains in strength. However, considering the stress that intense training places on the human body, athletes may derive certain benefits from supplementing with significant amounts of glutamine or combining glutamine with other supplements.

One study found that supplemented glutamine improved exercise performance and increased fluid and electrolyte intake in athletes suffering from mild dehydration when combined with glucose and an electrolyte drink. It has also been shown that glutamine supplementation can increase growth hormone levels in response to cycling training performed to exhaustion.

Extracellular glutamine concentrations have been shown to activate the mTOR signaling pathway, which is responsible for muscle growth by stimulating protein synthesis. In this context, however, it was necessary - as is so often the case - for other factors to be fulfilled in addition to glutamine supplementation. The mTOR signaling pathway appears to additionally require the presence of BCAAs - and leucine in particular - as well as a minimum level of cellular hydration.

In another study, track and field athletes who consumed 4 grams of glutamine per day in conjunction with a creatine loading phase and maintenance dose over an 8-week period showed greater gains in lean body mass than athletes who used creatine alone. This sounds significant, but it is difficult to draw definite conclusions after only eight weeks and such a low dosage. It would be interesting to know whether a higher glutamine dosage and/or a longer study duration would have resulted in significantly better results.

What different forms of glutamine are there and what should you combine glutamine with?

One of the most important factors to consider when choosing a glutamine product is the delivery system. If you are buying a powder, capsules or tablets, then free L-glutamine is the best choice. As creatine is unstable when dissolved in liquid, you should avoid drinks and bars that are supposed to contain glutamine.

If you prefer ready-made drinks or bars, then you should look for products that contain peptide-bound glutamine such as L-alanyl-L-glutamine, glycyl-L-glutamine hydrate or another glutamine peptide, which are significantly more stable than free glutamine. When dosing these products, however, it should be borne in mind that the amount of pure glutamine in such peptide forms is typically only 65 to 70%. In other words, 10 grams of glutamine peptides contain only 6.5 to 7 grams of glutamine.

Products containing n-acetyl-L-glutamine or alpha-ketoisocaproyl glutamine (aka aKIC glutamine) are best avoided. Even though these two forms of glutamine appear to be stable, there is evidence that they are poor glutamine suppliers.

Regardless of the glutamine form, up to 90% of orally supplied glutamine is eliminated during the so-called first pass by the liver, by the cells of the digestive tract or by the immune cells in the digestive system. This means that only a fraction of the glutamine consumed will ultimately reach the bloodstream.

After choosing a form of glutamine, it's time to think about what you can combine glutamine with to enhance its effects and/or take advantage of synergies. Most important is the intake of adequate amounts of sodium and electrolytes, as glutamine transport occurs using a sodium-dependent mechanism. Glutamine has been shown to significantly increase cell volume, electrolyte uptake and hydration. This can be beneficial for both endurance athletes and strength athletes. An increase in cell volume is particularly interesting for strength athletes, as a larger cell volume is one of the aspects that promotes muscle hypertrophy. In addition, a reduction in cell volume can inhibit the mTOR signaling pathway, which is essential for stimulating protein synthesis and muscle building.

Other active ingredients or supplements that can be combined with glutamine include the following:

• BCAAs: There are two reasons why combining glutamine with branched-chain amino acids (BCAAs) can promote greater gains in muscle mass and a greater increase in performance. The first is the ammonia concentration that can be influenced by glutamine, which means that glutamine has a direct effect on BCAA metabolism. The second reason is that the activation of the mTOR signaling pathway by extracellular glutamine first requires the intake of BCAAs and primarily leucine.

• Citrulline: Glutamine acts as a precursor for arginine and nitric oxide synthesis by transporting citrulline back and forth between tissue types. The use of glutamine in combination with citrulline may increase the ability of citrulline to stimulate nitric oxide production, which may lead to better oxygen and nutrient delivery to the muscles. A better supply of nutrients and oxygen to the muscles may mean better recovery and faster muscle growth.

• Alpha Ketoglutarate: Like glutamine, alpha ketoglutarate (AKG) serves as a precursor for glutamic acid and AKG has been shown to reduce glutamine degradation in a dose-dependent manner while increasing mTOR pathway activity and glutathione activity. This means that the combination of glutamine and AKG can increase the potential for muscle growth and the production of the body's most powerful antioxidant - glutathione.

• Glucose: When the body lacks glucose, it reduces glutamine uptake and impairs cell growth.

• N-acetylglucosamine: When following a low-carbohydrate diet, the glycoprotein N-acetylglucosamine appears to be able to restore glutamine uptake and glutamine metabolism impaired by glucose deficiency, potentially improving regeneration and cell function.

How should I take glutamine and does glutamine have any side effects?

In order to achieve a significant increase in glutamine plasma concentrations, the daily glutamine intake must be relatively high and should be at least 20 to 30 grams of glutamine per day.

As a comparison, it should be mentioned that critically ill patients usually receive a constant intravenous infusion of 20 to 30 grams of glutamine per day, whereby the bioavailability of glutamine in the form of an infusion is 100%. In comparison, the bioavailability of orally administered glutamine is only 30%. In order to obtain the amount of glutamine that seriously ill patients receive, one would therefore have to take around 70 to 100 grams of glutamine orally per day.

The recommended amount of 20 to 30 grams of glutamine per day should be divided into several evenly spaced doses throughout the day, preferably consumed with meals or snacks containing carbohydrates to support glutamine uptake and utilization.

On training days, glutamine should be consumed before or during training and after training to support hydration, electrolyte transport, BCAA metabolism and recovery. You can either take 10 grams of glutamine before, during and after training or reduce these doses to 5 grams of glutamine each and take the remaining 15 grams of glutamine throughout the day in the hours before and after training.

On non-training days, you should take 5 grams of glutamine every 2 to 3 hours at regular intervals to maintain an increased glutamine plasma concentration.

A cyclical intake with intake-free phases is not necessary with glutamine. Rather, there is evidence to support the need for continuous glutamine use during periods of heavy exercise.

As far as potential side effects of glutamine are concerned, there are numerous studies that have shown no undesirable side effects with glutamine doses of up to 30 grams per day. A recent toxicity study over a period of 13 weeks concluded that no side effects were observed in male and female rats, even with the highest amount of glutamine used. Converted to humans, the glutamine dosages used in this study correspond to 0.6776 grams per kilogram of body weight, which would correspond to 54 grams of glutamine per day for an 80-kilogram athlete.

Summary

Glutamine plays a key role in a variety of processes and bodily functions that have a dramatic impact on the ability to maintain overall good health and achieve individual fitness goals. However, if you rely solely on glutamine or don't use enough glutamine, then you may well be disappointed.

As with all supplements, you have to use your head with glutamine to maximize its effects. If you don't train hard, then your body will probably be able to meet its glutamine requirements without the support of supplements. However, if you are one of those exercisers who regularly push themselves to their limits, then the right use of glutamine can help to get your performance to a high level and keep it there.

Source: http://www.bodybuilding.com/fun/all-about-glutamine-your-expert-guide.html