Everything you need to know about glutamine. Controversial, but effective

 Everything you need to know about glutamine. Controversial, but effective

Many myths have arisen about the use of glutamine in sports, in connection with improving the effectiveness of resistance training. Glutamine has long been considered a substance that greatly enhances the growth of muscle mass.

The usefulness of glutamine has been called into question by studies, which have served as fertile ground for deletions and misinterpretation. When is it real? What is glutamine and how does it affect muscle fiber formation, hormones, muscle growth, stamina, endurance and fat burning?

What is glutamine?

Glutamine started getting a lot of buzz in the early '80s and '90s, more or less at the start of the creatine debate. Glutamine is a component of protein, an amino acid that distributes nitrogen in the body. This is especially important for athletes, as nitrogen is one of the protein components responsible for protein metabolism and facilitating muscle building:

When the nitrogen balance is positive, i.e. the body retains more nitrogen than it loses, muscle muscles formed from protein grow (anabolism processes occur)

If the nitrogen balance is negative, the organism undergoes processes of destruction of proteins and muscles (catabolic processes)


By ingesting glutamine, the body not only builds muscle and restores protein, but also produces more amino acids. What changed? In the late 1980s and 1990s, several studies were conducted (MacLennan from 1987, Millward 1989, Hammarqvist 1989, Guoyao and Thompson 1990) which confirmed that glutamine stimulates protein synthesis and inhibits

 their degradation processes. In 1990, Guoyao and Thompson demonstrated in a laboratory study that protein synthesis depends on the concentration of amino acids. For the highest concentration of amino acids, anabolism was increased by more than 58% compared to no concentration.

The impressive research results explain why glutamine increases muscle fiber synthesis and is an excellent supplement for training and protein supplementation.

How does glutamine affect muscle fiber synthesis?

Suspicion was cast on glutamine after the publication of a study by Louise Daldyk in 2008, which concluded that glutamine is a leucine antagonist in the process of the mTOR kinase enzyme. Leucine is an amino acid from the BCAA group, which affects the formation of muscle tissue. The enzyme mTOR kinase acts as a catalyst for protein synthesis in the

 muscles, that is, it stimulates protein growth and is responsible, among other things, for the growth and development of cells. The enzyme begins to work under the influence of anabolic hormones, especially insulin and amino acids such as leucine. Researchers as well as opponents of glutamine believe that it acts against leucine and that it inhibits the formation of proteins,

Where does this belief come from? The enzyme mTOR kinase is formed during the process of phosphorylation, that is, during the process of binding molecules, which in this case are serine molecules (a type of amino acid), with a specific phosphate radical. Dr. Deldicque's study was performed on muscle cells of mature mice, to which were added:

  • Lysine
  • or glutamine
  • or a mixture of both amino acids


When leucine was added to the substrate, the effect of the serine molecule increased by more than 50%, while the effect of the serine molecule increased by 8 times. The addition of glutamine actually reduced the activation of the serine molecule by about 25%. In the latter case - the amino acid mixture increased the phosphorylation of the serine molecule by more than 40%. Activation of the ribosomal protein is important throughout the mTOR process because it is what activates anabolism.


The moment of truth is the measurement of the concentration of contractile proteins in the muscles. And there was a feeling! Under the influence of leucine the concentration was 10% and under the influence of glutamine 40% and the amino acid mixture the concentration increased to 270%. These results indicate that glutamine has significant anabolic properties (four times more than leucine), and if the two ingredients are combined together, there is a 30-fold increase in anabolic properties.

Recent studies (Evans, 2007) prove that if the level of glutamine decreases, the intracellular concentration of leucine also decreases, because glutamine transports leucine within cells. So the more glutamine and leucine, the more muscle growth.

How does glutamine affect hormones and muscle growth?

According to the latest research (such as Li in 2004), glutamine acts as a mediator in the release of insulin from the cells of the pancreas, which is said to be the most powerful anabolic hormone in the body. This is the case for thin and obese but healthy people, as well as for obese and sick people.

Glutamine facilitates insulin secretion and increases its activity, which means that it improves insulin sensitivity. However, it must be added that it is an effective anabolic for:

muscle tissue

and adipose tissue - the effect may be an increase in the amount of fat. On the other hand, there are studies that also show that glutamine can be a fat burner.

Glutamine also increases the level of IGF-1, in short: the growth factor that is secreted under the influence of growth hormone. Glutamine can maintain a high level for a long time, even up to 70%. Positive effects were observed for both the young group and the elderly group.

In 2007, Sharp conducted an experiment on eight athletes who train intensely. He separated them into two groups, in which they performed intense strength exercises for 4 consecutive weeks. The first group received 2 grams of glutamine and 4 grams of BCAAs per day and the second a placebo. For the first group, the value of the ratio of testosterone to cortisol,

 which indicates the anabolic ability of the body of an athlete performing strength exercises, increased by more than 7 times. Most importantly, glutamine not only reduces the amount of cortisol in an athlete's body, but also prevents cortisol catabolic processes, that is, the breakdown.

However, it should be noted that glutamine has the ability to inhibit cortisol, but only when used as a supplement and not as amino acids found in dietary protein.

Another catabolic hormone is TNF-alpha factor, which stimulates the production of myostatin in the muscles. Glutamine reduces muscle myostatin levels by about 130%. Most TNF-alpha is formed during anaerobic exercise, which often damages muscle fibers. For example during bodybuilding training.

How does glutamine increase the body's immunity and endurance?

Glutamine is not only an ideal anabolic agent that reduces the activity of catabolic hormones, but also improves the body's immunity.

One researcher (Carroll, 2004) gave a natural blend of nutrients to dozens of critically ill patients and another rich in glutamine. In the placebo group, he noted an improvement in protein balance by up to 120%.

Glutamine improves immunity and prevents muscle damage caused by bacterial infections. Glutamine is also useful in cases of severe muscle fatigue (cachexia) associated with the development of a serious and serious disease, such as cancer. After Maya's trial in 2002, a

 group of patients received a combination of one amino acid and another (experimental) 14g of glutamine, along with arginine and HMB. Muscle mass in the glutamine group increased by 1.12 kg during 4 weeks, while it decreased in the other group by 1.34 kg.

The use of glutamine increases the concentration of glycogen in the muscles, allowing the athlete to train for longer and with a heavier load, because their muscles are larger and stronger. Although the use of glutamine can improve strength by only 1%, for an athlete of 100 kg, this means an increase of 1 kg per bar. If the muscle mass increases by 0.3%, it seems small, but in fact it gives about 150 grams of additional muscle, which gives an increase of 1.2 kg per year. To achieve such a result is not easy for a bodybuilder.

Incredible results were also achieved in bodybuilding with the Hakimi trial in 2012. The researcher divided 30 students into two groups, each of whom completed an intense 8-week workout. The former consumed 25 grams of glutamine per day or an equivalent amount of starch. Comparing the results with the control group resulted in very positive hormonal

 changes: growth hormone - an increase of 303%; testosterone - 128% increase; IGF-1 - 115% increase; Cortisol - 433% lower. This was translated during training as: bench exercises - placebo - score improved 3.53, glutamine - score improved 6.25, squat - placebo

 - score improved 3.54, glutamine - score improved 6.02; muscle mass - placebo - 0.9 increase, glutamine - 2.9 increase; Adipose tissue - placebo - 0.2 reduction, glutamine - 0.6 kg reduction. As you can see, significant changes are observed in the hormonal sphere and not with exercises ...


Does glutamine help reduce fat?

Glutamine is also used when we are cutting carbs and looking for a good weight-burning agent. It is found in nutrients to increase mass.

On the one hand, glutamine has an effect similar to carbohydrates, but on the other hand it reduces weight while maintaining all the required properties. Plus, we save time - according to studies, six weeks of taking a glutamine supplement increases strength by 6% and muscle growth by 2%.

Obviously, glutamine perfectly complements strength and fitness training. It is not only a tonic, but also a fat burner - it promotes the reduction of adipose tissue. Important is the synergistic effect of glutamine (a nutrient for gaining muscle mass), with creatine and BCAA (leucine, isoleucine, valine). If we want to increase muscle mass and strength, a

 small dose of glutamine is sufficient. For excellent results and muscle fiber synthesis, it is important to remember to combine glutamine, creatine and BCAAs. It is not necessary to use high doses, it is enough to take 2-14 g. So we gain efficiency, at a lower price and benefit from the base of bodybuilding and fitness sports.

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