Essential amino acids, what is their role in muscle growth?

When you started bodybuilding, you wondered if your protein intake was sufficient. The label of protein powder boxes actually listed the basic components of these proteins, namely amino acids. As you know, these are the first constituents of a protein . By definition, it is an organic acid linked to an amine base, but that doesn't really tell you anything more. If you were told instead that it is a source of nitrogen (NH3), that would already make more sense. Indeed, to determine the protein content of a food, we measure its nitrogen or nitrogenous base content. In addition, essential amino acids are those that your body cannot synthesize, unlike others, considered non-essential.

Structurally, amine bases (NH2 or 3) and organic acids (COOH) make up the primary skeleton of amino acids. A radical made up of another molecule will be added to this primary structure. Each molecule linked to its radical will give the amino acid its identity. Thus, Glycine is the simplest amino acid because it has no radical. Then, different radicals will attach to this basic structure to form the other amino acids, essential or not. And while nature has hundreds of amino acids, only 21 of them are recognized and used by our genetic code. Of these 21 nitrogenous molecules, eight of them are considered essential.

Essential and non-essential amino acids, a fairly relative classification

What we do know is that each amino acid has a specific structure that gives it its properties. Those we consider essential are not synthesized by our bodies. Some of them are characterized as conditionally essential and others as non-essential. In fact, this kind of definition is quite shaky to begin with. For example, glutamic acid (L-Glutamine) would be considered conditionally essential, depending on the body's needs. However, glutamine requirements vary widely depending on the conditions. For example, glutamine has been used in hospitals for burn victims to reduce the accelerated catabolism of muscle mass after this trauma. This is easily explained since it represents the main nitrogen transporter in the body.

From there, the use of glutamine was extrapolated to bodybuilding, but it first appears that this amino acid is essential for intestinal health in healthy individuals. From this perspective, having healthy intestines is a key condition for the assimilation of amino acids, fatty acids, and carbohydrates, each of which contributes to muscle growth. In any case, L-Glutamine requirements can vary depending on the individual and the circumstances. This is also the case for L-Tyrosine and L-Tryptophan, a precursor of catecholamines on the one hand and serotonin on the other. From there, the notion of essentiality or conditionality becomes relative, to say the least.

Glycine is much more essential than one might think at first glance.

It's a bit the same for glycine. Indeed, we have known for years that glycine intake is clearly insufficient in humans, mainly due to a genetic deficiency. This is a relative deficiency already noted in other mammals by scientific research. Therefore, glycine should also be considered essential. Indeed, glycine is particularly useful for many organic functions. Energy metabolism (glucose and creatine), synthesis of hemoglobin, neurotransmitters or glutathione and collagen cannot be satisfied without glycine.

Being the simplest amino acid structurally speaking, it can be used for the formation of other amino acids such as glutamine and serine for example. From serine, pyruvate will be synthesized to then find the synthesis of glucose and cellular energy. Glycine also participates in the formation of purines, a type of molecule directly linked to our DNA. However, glycine is best known for its role in collagen synthesis. The molecular complexes of collagen are also made up of one glycine molecule for every three amino acids in this chain. We can therefore think that glycine should be one of the highest priority dietary supplements, especially as we age and joint problems become more frequent.

Essential amino acids contribute to muscle growth through different mechanisms

Considered essential, these are specifically histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. Methionine is necessary in the sense that it is in the first position during protein synthesis. This situation would be, according to research, due to genetic coding, without the essential notion of protein stability having prevailed over this choice. Still, we cannot generate proteins without this amino acid. On the other hand, the much-debated question of BCAAs or branched-chain amino acids is a little more complex.

While it is true that leucine, isoleucine, and valine all play a role in protein synthesis in one way or another, taking BCAAs in isolation does not significantly increase muscle growth when other amino acids are not present in the diet. Similarly, taking BCAAs in isolation could create competition for assimilation, particularly for tryptophan. Conversely, tyrosine is classified as non-essential, even though it is essential for the generation of many neurotransmitters such as dopamine, adrenaline, or noradrenaline, for example, as well as for thyroid hormones. Therefore, a tyrosine deficiency is not desirable. It must therefore be admitted that this classification into essential and non-essential is quite relative, especially when we consider that the nutritional needs of athletes in amino acids increase with the intensity of the exercise.

Essential amino acids contribute to muscle growth, but so do others, even indirectly.

Overall, it is important to remember that the notion of amino acid essentiality is only relative, and this is particularly the case for glycine and glutamine. While glycine needs are largely underestimated, glutamine nutritional needs depend greatly on individual conditions and other factors. For these many reasons, YAM Nutrition now offers Bombi because it provides you with the eight essential amino acids as well as taurine rather than just BCAAs. On this subject, many bodybuilders will tell you that BCAAs give them energy during training. However, the primary source of muscle energy remains glucose. When your glycogen stores are at their highest, it is true that BCAAs will also participate in energy release, but this is even more true when all 8 essential amino acids are involved. As for post-exercise recovery, this notion is even more essential since BCAAs alone are not able to sufficiently stimulate muscle hypertrophy.

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