Glycine and Leucine

When you talk about amino acids , most coaches, trainers and nutritionists will roughly tell you that we separate those that are essential from those that are not while roughly giving you the basic characteristics of some of them… However, scientific research affirms that two amino acids in particular, Glycine and Leucine, would be particularly useful to amateur and professional bodybuilders and bodybuilders.

While we know that essential amino acids are not synthesized by our bodies, the question is more delicate for non-essential amino acids, or at least for those that are sometimes characterized as conditionally essential. In reality, this means absolutely nothing except to mention that the metabolism of amino acids is particularly complex. Under these conditions, could we isolate one or more amino acids while favoring their nutritional contribution over the others? This is precisely the question we will attempt to answer...

Are Glycine and Leucine Two Different Amino Acids?

In most cases, you will be told about several amino acids forming peptides or proteins, but you will rarely be told about isolated amino acids. However, supplementing with Glycine or Leucine has been proven several times in numerous clinical studies to provide significant nutritional support, particularly in the context of muscle growth and other metabolisms more or less directly related to it.

Glycine is the precursor of phosphocreatine and collagen protein

Glycine is an amino acid that serves as the basis for the synthesis of creatine along with L-Methionine and L-Arginine. Indirectly, taking a Glycine supplement also provides your body with the raw material necessary for the formation of endogenous creatine , regardless of your age . However, Glycine is primarily considered the essential amino acid for the synthesis of a structural protein, the Collagen . Once considered a secondary protein, collagen is present in all tissues of the body, in connective tissues and even in your muscles.

Glycine is essential for the synthesis of collagen in our body and our muscles.

At the level of your ligaments and joints, Glycine, by stimulating collagen synthesis, indirectly plays an improving role in the synthesis of joint tissues and naturally reduces the potential risks of osteoarthritis. Inflammation of joint tissues, osteoarthritis is not only linked to age but can also be due to the intensity of the weight training exercises you have been doing for years. Indirectly, glycine helps reduce these symptoms by stimulating collagen synthesis.

Collagen becomes increasingly essential for muscle growth with age

As we mentioned above, collagen is a structural protein that is also found in muscles. Type I and III collagen is found in muscle mass with which it binds. Scientific field studies also tend to prove that collagen would be increasingly essential as age advances. If it is a protein that is a priori of little significance on the muscle growth At 20, 30, or 40 years old, its influence is significantly greater. Here too, taking glycine or collagen powder could prove beneficial for muscle growth.

The leucine level of a protein will stimulate muscle protein synthesis with more or less intensity

Leucine, the first branched -chain amino acid in terms of metabolic importance, cannot, however, do without L-Isoleucine and L-Valine. Leucine triggers protein synthesis via the mTOR/AKT/p70S6K pathway. In other words, if the leucine level in a protein is insufficient, it will not stimulate muscle growth. Conversely, if the leucine level is too high, gluconeogenesis will be initiated, leading to the use of amino acids for energy purposes. This is easily explained by recalling that leucine is insulinogenic, it plays a similar role to insulin for glucose.

Glycine and Leucine, two amino acids to combat sarcopenia and loss of muscle mass

On the other hand, protein assimilation becomes increasingly difficult over time. Indeed, the intestines will tend to sequester more and more amino acids in order to meet their energy needs, to the detriment of blood amino acid levels. Here too, scientific studies have found that increasing Leucine intake with age stimulates anabolism. Obviously, if you are over 40 or 50 years old, Leucine could be added to your protein , at a rate of 5 to 10 grams per day , depending on your physical activity.

So, even if you're already taking protein powder, adding a few grams of Glycine to a glass of water and a few grams of Leucine to your protein shake could provide a significant benefit to muscle growth, especially if you're in your early 20s.