Amino Acids BCAA in Bodybuilding: Scientific Reviews of Their Effectiveness for Muscle Gain, Weight Loss, Side Effects | PRO7fitness.com

BCAA (Branched-Chain Amino Acids) are widely used today in bodybuilding and fitness: they mysteriously peek out from the gym bags of Instagram fitness enthusiasts and are confidently consumed by professional bodybuilders to fuel their inhuman physical workloads.

BCAA is one of the most popular types of sports nutrition, alongside protein and creatine… although it is quite controversial.

Doubts arise about some properties of this supplement, which are often touted by marketers or human imagination, prone to glorifying anything that is beneficial. You will understand what is meant as you study the results of scientific research on the effectiveness of BCAA.

Below, we will explain what BCAA amino acids are and why they are needed in bodybuilding, as well as present some scientific studies that have led to the widespread fascination in the world of bodybuilding and fitness with the mysterious abbreviation “BCAA”.

What are the “BCAA amino acids”?

BCAA (Branch Chain Amino Acids) are three of the nine essential amino acids that are vital for the human body and must be regularly obtained from food.

They include: valine, leucine, isoleucine.

The importance of BCAAs for the human body is highlighted by the following figures: 35% of essential amino acids in our muscles are BCAAs, and 40% of the essential amino acids necessary for humans (in quantitative terms) are attributed to them ¹⁵.

Advantages of BCAA in Sports and Bodybuilding

The popularity and benefits of BCAAs in sports are most often explained as follows:

• they are the building material for muscle cells, i.e., they directly participate in muscle growth and recovery;
• BCAAs delay the feeling of fatigue during training;
• they are beneficial for weight loss/fat burning;
• BCAAs also help regulate blood sugar levels and improve carbohydrate metabolism.

Next, we will go through each of these points and provide some scientific facts for (or against). How convincing they are – you will decide for yourself.

Important note: from a practical point of view, the significant question is not “what are BCAAs needed for?”, but “is it worth taking them as a sports supplement or is regular protein sufficient?” As you read the article, look for the answer to this question.

We recommend: How to take BCAA amino acids and is it worth it? Maybe protein is better?

1 BCAA amino acids are beneficial for gaining muscle mass

If we were to ask the question “what are BCAAs needed for?” to representatives of bodybuilding, the overwhelming majority would answer that they play a colossal role in muscle growth.

And this is indeed the case.

When protein from food enters the body, it is broken down during digestion into individual amino acids (including BCAAs), which enter the bloodstream and are transported to the muscles, providing them with building material.

If we take amino acids in the form of supplements, they almost immediately enter the bloodstream, as they do not require digestion.

A sufficient presence of amino acids in the blood is one of the most important conditions for anabolism (muscle growth and recovery). See Proper nutrition for gaining muscle mass: 7 recommendations from experts.

Leucine – one of the three BCAA amino acids – is considered the most (anabolic), i.e., important for maintaining and increasing muscle mass ¹¹.

It directly stimulates muscle protein synthesis and acts as a kind of trigger for the process of connecting individual amino acids into molecules of muscle proteins.

Leucine also raises insulin levels – one of the anabolic hormones in our body (along with growth hormone and testosterone).

(The mechanism of action of insulin is the basis for a type of sports supplement known as gainers for muscle mass gain.)

Another mechanism of action of BCAA amino acids for muscle mass gain in bodybuilding is that they stimulate the increase of growth hormone levels.

A sufficient amount of amino acids in the diet is one of the natural factors for its increase, as amino acids are structural components from which hormone molecules are synthesized in our body.

The benefits of BCAA amino acids for muscle mass gain are explained by the fact that they include one of the most powerful amino acids for muscle growth – leucine.

Recommended: Powerful and deadly.. The mechanism of action of insulin in bodybuilding for muscle mass gain and weight loss.

Scientific research on the benefits of BCAA in bodybuilding for muscle mass gain

Benefits of BCAA for untrained men

Adding 4 grams of isolated leucine to the diet of untrained men (protein intake – 0.90 g/kg), training for 12 weeks, led to a 40.8% increase in strength, while those who did not take it had a 31.0% increase; at the same time, muscle mass and body fat percentage did not change ²⁵.

Not a very indicative result.. in terms of mass gain.

The results of the following experiment are interesting:

Benefits of BCAA for mass gain in bodybuilding and weight loss

In trained men, taking 14 grams of BCAA per day for 8 weeks along with resistance training led to a 2.2% reduction in fat mass and a increase in muscle mass by 4.2 kg – this is better than taking 28 grams of whey protein throughout the day (2.1 kg of muscle mass and 1.2% body fat) or 28 grams of carbohydrates (1.4 kg of muscle mass and 0.6% fat) ²⁶.

The result is impressive and deserves special attention. A thorough examination reveals the following facts:

• The exact diet was not documented or controlled (it is unclear what the athletes ate besides BCAA);
• The BCAA supplement used contained glutamine (5 grams), Citrulline malate (2 g), and vitamin B6;
• The study itself was funded by the sports nutrition manufacturer – Scivation, and it used their BCAA supplement known as “Xtend”;
• The author of the study, Jim Stoppani, is a “guru” of bodybuilding, “playing” simultaneously for the well-known online sports nutrition store bodybuilding.com (as an author of “scientific” articles) and for Scivation.

There are quite a few studies on the benefits of BCAA amino acids for muscle mass gain, and most of them confirm a certain positive effect. We have provided only two to demonstrate the controversy.

The specificity of most experiments is that they are often conducted under conditions of dietary restriction, where participants consume insufficient protein and calories…

In such a state, muscles will grow even on carbohydrates. We discussed this issue in detail in the material about how to take BCAA and whether it is worth it.

Let us remind you that according to the principles of proper nutrition for muscle mass gain in bodybuilding, a necessary condition for muscle growth is not only the adequate intake of all amino acids from protein but also its overall caloric content, which is provided by fats and carbohydrates.

Scientific research on the effectiveness of BCAA for muscle mass gain is contradictory; overall, they confirm their effectiveness, but the problem is that they are often conducted under conditions of caloric and protein intake restriction in the diet.

2 BCAA amino acids allow for longer training sessions, delaying the onset of fatigue

The feature of BCAA amino acids is that when they enter the body, they are transported directly to the muscles, while most other amino acids first go to the liver, which “decides” what to do with them: either use them as fuel or direct them to tissue building and recovery.

This property explains another reason why BCAA are needed in bodybuilding: during training, they help supply energy to the working muscles, and afterward, they serve as building material for creating new or repairing damaged muscle cells.

That is why it is important to have an adequate presence of these amino acids in the blood both during and after training.

The longer and more intense the training, the greater the likelihood of using BCAA amino acids as fuel.

The primary source of energy for working muscles is carbohydrates, specifically – glucose and glycogen. When carbohydrates are insufficient or their stores are depleted during prolonged training, amino acids can be used for energy.

This is not very good.

The situation can be compared to heating a house with bricks (if they could burn) instead of firewood. Naturally, this is expensive. To prevent this from happening, it is primarily important to control the adequacy of carbohydrate intake from food. This is why pre-workout complexes were invented, but there is nothing specific about them.

The only justified situation when scientists recommend taking BCAA is during calorie-restricted diets, inadequate nutrition, when there is a high risk of muscle tissue breakdown. In particular – during “cutting” in bodybuilding.

Scientists and experts from Examine.com ³⁵ note that some athletes (not all, mainly beginners) find that taking BCAA really helps them feel more energetic and train with greater intensity.

Why specifically beginners? Probably because they do not yet understand how to eat properly and simply do not provide the necessary caloric intake, substituting the lack of carbohydrates with BCAA supplements.

BCAA amino acids delay the onset of mental and physical fatigue, as they can be used for energy. This is not an advantage, but rather indicates inadequate nutrition.

We recommend: Proper nutrition for gaining muscle mass: 7 recommendations from experts and How to gain muscle mass: a guide for beginners

The effect of BCAA intake among endurance runners

A study published in the Journal of Sports Science and Medicine ² confirms the effect of BCAA intake in combating fatigue during strength training among endurance runners.

Scientists provided the following explanation: it is likely that BCAA intake slows down the production of serotonin in the brain, the increased level of which is one of the factors contributing to the feeling of fatigue during physical exercise.

The intake of BCAA by runners led to a reduction in central nervous system fatigue over two consecutive days of competition, allowing them to run faster at the same perceived mental and physical exertion.

Based on this, researchers concluded that BCAA may be particularly beneficial for athletes participating in multi-day competitions.

Experiments involving athletes from sailing ²⁷, cyclists ²³, marathon runners ³³, and football players ³² indicate a reduction in perceived fatigue.

The effect of BCAA intake among cyclists

In trained cyclists taking BCAA (90 mg/kg body weight in a ratio of 40% valine and 35% leucine) during cycling and assessing their feelings of fatigue every 10 minutes, a 7% reduction in physical fatigue and a 15% reduction in mental fatigue were noted, with the effect of BCAA combating fatigue also recorded after the workout ²³.

– Did BCAAs help cyclists ride faster?

No significant improvement in performance was noted among cyclists taking BCAAs: only three said yes, while four said no ²³.

Any improvements were also absent in trained cyclists who took 6-18 grams of BCAAs ³⁴.

Not a very impressive result..

The benefits of BCAAs for marathon runners

The intake of BCAA amino acids by marathon runners was accompanied by a reduction in the feeling of fatigue only in those who ran slower, not in the fast ones ³³.

It seems that in aerobic exercises, such as cycling and football, additional intake of BCAAs in the form of supplements leads to maintaining mental concentration for a longer time and to reducing mental fatigue.

The likelihood that BCAA consumption affects physical performance levels is very low, possibly only in untrained individuals.

The intake of BCAAs helps maintain mental concentration and reduce mental fatigue, but it is unlikely to affect physical performance levels, possibly only in untrained individuals.

3 BCAAs accelerate recovery after strength training

According to studies, when BCAA amino acids are taken in bodybuilding before or after damaging strength training, the concentration of muscle damage markers decreases, and the recovery process is accelerated.

This happens because “BCAA amino acids improve muscle protein synthesis and thus reduce the degree of muscle breakdown during active strength training” ⁶.

The intake of BCAAs leads to a decrease in the levels of two substances (creatine kinase and lactate dehydrogenase), which are associated with muscle breakdown (the higher their concentration, the greater the degree of breakdown) ⁷.

Scientific research indicates the benefits of BCAAs for recovery in sports, as they prevent muscle tissue breakdown during intense training.

4 BCAAs reduce muscle pain during and after bodybuilding training

Despite some controversy in scientific data regarding whether BCAA amino acids help reduce muscle pain after training, it seems that they are indeed effective in this regard.

This is confirmed by an experiment in which untrained women took BCAA amino acids and performed a large number of squats. The next day, they experienced significantly less delayed onset muscle soreness – pain sensations in the muscles that occur several hours or days after intense and unfamiliar physical activity ²⁴.

BCAA amino acids reduce muscle soreness after strength training in bodybuilding, as they prevent the breakdown of muscle cells during exercise.

5 BCAA Amino Acids are Beneficial for Weight Loss

BCAA amino acids are also beneficial for weight loss: their intake has been shown to lead to weight normalization and fat reduction.

Overall, a high-protein diet is beneficial for weight loss and maintaining body weight for women and men of different ages ¹⁸.

In one study involving wrestlers, the intake of BCAA supplements along with a low-calorie diet proved to be much more effective for weight loss than simple calorie restriction ¹⁹; relative mass was measured not only for subcutaneous but also for visceral fat ²⁰.

A possible explanation: when protein synthesis increases, energy levels rise. Additionally, leucine (a protein) is more satiating and reduces feelings of hunger.

BCAA amino acids are beneficial for weight loss, but further research is needed to understand if they have advantages compared to protein.

Conclusion

BCAA amino acids play a colossal role in sports for muscle mass gain, combating fatigue, accelerating recovery, and for weight loss.

However, a logical question arises: if BCAAs are already present in quality protein, is there any point in taking them as supplements, or is it enough to just consume complete protein?

As we noted above, most scientific experiments proving the benefits of BCAAs are conducted under conditions of calorie restriction and limited protein intake. This makes them biased.

We are convinced, and our opinion is supported by many modern scientists, that when the diet contains enough quality protein, there is NO need to take any amino acids, including BCAAs. Those who do so significantly increase the risk of harm and even the occurrence of cancer.

We recommend: Reviews from scientists and doctors on what is better: amino acids (+BCAAs) or protein?.