BCAA: What it is and why it is important for muscle growth | Xcore Nutrition

You may be on the fence with some sports nutrition products, but BCAA should not be one of them. In this article, I’ll explain what these extraordinary amino acids are and what they can do for your muscles.

What is BCAA?

BCAA (essential amino acids) for muscle growth

You have undoubtedly heard the sentence “proteins are the building blocks of the muscles.” It may sound cliché, but it’s true, nonetheless. The human body does use protein to build muscle tissue. It’s the basis of the anabolic process, where the body uses a simple element, protein, and metabolizes it into a more complex material, muscle tissue.

The proteins we eat are made of individual amino acids. Among them, you’ll find a group called essential amino acids, which the body cannot produce by itself, so you must obtain them through your diet. There are nine essential amino acids: Histidine, Isoleucine, Leucine, Lysine, Methionine, Phenylalanine, Tryptophan, and Valine.

Within the essential amino acids group, you have the BCAA — Branched-Chain Amino Acids — a special group of three specific amino acids, Leucine, Isoleucine, and Valine, that, as the name suggests, are molecularly chained together.

The three BCAA are fundamental to the human body, comprising roughly one-third of the amino acids within muscle tissue, so if muscle growth is your goal, BCAA are crucial.

  • Leucine is a hydrophobic amino acid, and it can be found as a structural element on the interior of proteins and enzymes. It provides ingredients for the manufacturing of other essential biochemical components in the body.
  • Isoleucine is a member of the aliphatic side-chain amino acid family. Just like Leucine, it provides the components for the synthesis of other essential elements in the body.
  • Valine is what is called an aliphatic amino acid, and it is closely related to Leucine and Isoleucine, both in structure and function.

Why is BCAA important for muscle growth?

Intense exercise and/or dieting are two especially catabolic activities that most athletes go through. High-intensity sports subject the body to extreme muscle stress, causing damage to its cells. In a way, muscle is destroyed while you train. Concerning dieting, the leaner an individual tries to get, the harder it is to keep their muscle mass intact. As fat stores become depleted, the body turns to muscle, breaking down lean tissue to use as energy.

This muscle breakdown process occurs to release the amino acids in the tissues, which are then converted into usable fuel. To revert this process, you must promote muscle synthesis. Failing to achieve this means you will be breaking down more muscle than what you can build. In other words, you will get smaller.

This is where BCAA come in, as they are incredibly effective at promoting protein synthesis, making sure you gain more muscle than what you burn.

BCAA for muscle growth - essential amino acids

How does BCAA work?

BCAA supplementation can enhance the anabolic environment in the body while preventing catabolism in athletes at the same time. In other words, BCAA have a positive dual effect, helping you gain muscle faster and retain more of your existing muscle tissue at the same time.

Another great reason to take BCAA is when you take time off due to injury since it limits the amount of muscle loss and fat gain. BCAA work as the fuel to preserve muscle in the body, whether you are training or not.

BCAA also signals the mammalian target of rapamycin, known as the mTOR pathway, a biological mechanism that regulates energy and lean tissue production.

The mTOR is responsible for detecting an excess of amino acids. When you take BCAA and activate the mTOR, it’s as if you’re telling your body there are plenty of amino acids flowing through the plasma, and that this mechanism should start using more of them to synthesize muscle tissue.

Combined with resistance training, it sends messages that control growth right at the cellular level. So, again, it’s hypertrophy times two: on the one hand, you’re working out to develop your muscles with training, and, on the other hand, you’re optimizing your body’s metabolic response to amino acids.

Taking BCAA vs. Whey Protein

Some would argue that you can find the sufficient BCAA dosage in complete proteins, which is true. But as a matter of fact, the three BCAA together are metabolized differently from the other amino acids. Complete proteins, such as whey protein, are peptide bounded, which means you must digest them to release the amino acids that compose them.

Taking a free-form BCAA supplement enables you to use Leucine, Isoleucine, and Valine immediately, shooting it straight through the digestive tract and into your bloodstream very rapidly.

Aim for a BCAA dosage between 3 and 5 g per day, preferably through a free-form BCAA supplement, and take before, during and after training.


BCAA supplementation is exceptionally effective in enhancing muscle building, both by triggering hypertrophy and by preventing catabolism. The evidence supporting these effects is solid, making BCAA one of the most trustworthy supplements in the sports nutrition industry.

If you train to enhance muscle mass, or are worried about losing the muscle tissue you have – for instance, while dieting – BCAA should be one of the first products to have in your supplement stack.


paulo fernandes xcore nutrition athlete

Paulo Fernandes


I have always been an extremely competitive person. I had competed in several sports until I discovered the bodybuilding. In my first bodybuilding competition, I won the national champion title, and I had prepared for the challenge all by myself. Since then, I have been raising my own goals. I…

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