Branched chain amino Acids better known as BCAAs are one of the most talked about supplement in sports nutrition. Primarily used by individuals involved in resistance training, many swear by it as a panacea for muscle growth. However, is the scientific evidence regarding BCAAs and muscle growth strong? BCAAs have also been claimed to help in faster recovery and relieving muscle soreness. Additionally , it has also been marketed as improving cognitive function of athletes post exercise and increased muscle protein synthesis. The evidence to the aforementioned claims is not always convincing.
The efficacy of BCAAs might vary from athlete to athlete. Endurance athletes seldom benefit from them while bodybuilders and powerlifters strongly endorse them. Supplements have their own set of risks, and one needs to have a proper strategy to maximize their benefits. One can check out my earlier blog post on the same .
Before I go into the details of the claimed benefits of BCAAs and their effectiveness, let us learn a bit more about BCAAs and how they work.
What are BCAAs?
Amino acids are organic compounds containing carbon, hydrogen, nitrogen and oxygen as the main elements. Amino acids combine to form proteins, one of the three major macronutrients required for healthy functioning of the human body. 20 different amino acids form the basis of many different proteins in our body. Out of these 20 amino acids , 9 amino acids are essential . The body can make the remaining 11 amino acids if the 9 essential amino acids are available to the body from one’s diet.
As can be seen from Fig 1, BCAAs consist of three amino acids Leucine, isoleucine and valine . They are termed as “Branched chain” because these are the only three amino acids which have a branch off the main body of the molecule. BCAAs cannot be synthesized in our body , hence must be obtained through our diet. Thus BCAAs are essential amino acids.
However, does supplementation help with performance, or can it be obtained through our diet if we meet our total protein intake? Some of the commonly made claims regarding BCAAs are
- BCAAs reduce muscle damage
- They help in exercise performance
- They spare muscle glycogen, a critical factor for endurance athletes
- BCAA supplementation increases protein synthesis
- BCAA can act as a fuel during exercise
Though BCAAs are an essential part of our diet , studies have not always established a strong link between BCAA supplementation and the aforementioned claims.
Does BCAA supplementation help in muscle growth?
One of the most common claims made by BCAA supplements is that helps in muscle protein synthesis. However, this is a highly misleading claim to make. The metabolic mechanism for the growth of muscle is net muscle protein balance. Protein synthesis , i,e muscle protein synthesis must be greater than muscle protein breakdown for muscle growth to occur. Indeed BCAAs help in the process, but so do other essential amino acids. It is often claimed that BCAA’s can enhance protein synthesis by stimulating the signaling pathways in the contracted protein muscles. However this can just as easily be achieved with consumption of protein through diet or a protein drink. Without an increased intake of protein there will be no muscle protein growth.
As explained earlier, for protein growth to occur the muscle protein synthesis must be greater than the breakdown. BCAA alone will not suffice for this purpose we need all the nine essential amino acids. Essential amino acids are necessary to simulate the signaling pathways for protein synthesis and to act as building blocks. The in-vitro studies (studies which are carried out in human cells) and animal studies claiming the effectiveness of BCAA supplementation for muscle growth, have not been replicated in healthy gym going adults . Thus one cannot come to a definitive conclusion that BCAA supplementation can enhance muscle growth in humans.
Additionally, let us take a closer look at the amount of each acid per dosage , from a leading brand:
Let us compare the BCAA supplement above with 100 gm chicken breast.
|Amino Acid||Supplement per serving||Chicken Breast (100 gm)|
|Leucine||500 mg||656 mg|
|Iso -Leucine||250 mg||375 mg|
|Valine||250 mg||470 mg|
Based on Table 1, one can conclude chicken breast provides far superior amounts of BCAAs than supplements. This raises a major red flag . Why would you want to buy a supplement when you can get better results from your food? Peanuts are also rich in BCAAs. 60 gm of peanut would contain the equivalent of 5 servings or 10 tablets of the aforementioned brand of BCAA supplement. Hence, one must look towards quality dietary protein to meet their BCAAs requirement.
However, one should bear in mind that currently there is evidence to suggest BCAA supplementation can help reduce muscle soreness after heavy bouts of exercise. It should be noted that though significant improvements in muscle soreness was observed by Jackman , Jeukendrup and colleagues , BCAA supplementation was not found to change the exercise induced decrements in muscle function. Hence, it would depend on the athlete to decide for competitions if BCAA supplementation can provide some relief.
Does BCAA help in improving performance
A study carried out by Blomstrand et al 1997 , compared flavored water solution with a BCAA infused solution in seven endurance trained cyclists who cycled for 20 minutes followed by 1 hour of exercise . The researchers did not find any improvement in their exercise performance. In a controlled study performed by Dr Van Hall et al , when a 6% sucrose solution administered to athletes was compared with 6% sucrose plus both a low and high dose of BCAA (6 gm/L and 18 gm/L respectively), there was no difference in performance. The time to exhaustion remained the same between the athletes who consumed the sucrose solution and those who consumed the BCAA infused solution.
Many other studies carried out on the effect of BCAA administration (oral, with carbohydrates, liquid etc ) failed to establish an improvement in exercise performance among endurance athletes. Endurance athletes are more likely to benefit from nitrates, especially beetroot juice for improved performance.
At present there does not seem to be enough high quality evidence to suggest BCAA supplementation . If you are an elite body-builder you could possibly benefit from BCAAs to reduce muscle soreness. However, more often than not one comes across regular gym goers whose primary goal is to stay fit and maintain a reasonable amount of muscle mass consuming BCAAs. Definitely such individuals will not benefit from BCAA supplementation. Needless to say BCAA does not help endurance athletes much . Hence without strong evidence the use of BCAA for endurance athletes is questionable .
Athletes should rely on a high quality protein rich diet which meets their total protein requirements and contains all essential amino acids. A nutritious high quality diet will play a greater role in recovery, exercise performance and muscle growth than relying on supplementation.