Branched chain amino acids, better known as BCAAs, have become synonymous with sports nutrition. Yet there appears to be some debate as to whether BCCAs are effective for building muscle; it is argued that essential amino acids should be the go to supplement for bodybuilders.
Proponents of BCAA supplements claim that BCAAs stimulate the mTOR pathway and muscle protein synthesis, while critics of BCAA supplements argue that EAAs are superior because they are the rate-limiting factor of muscle hypertrophy.
This article explains exactly what BCAAs and EAAs are, and evaluates their efficacy for building muscle according to scientific-evidence.
This article also answers the following questions:
- Can you take both BCAA and EAA?
- Should I take BCAA every day?
- Do you need BCAA If you take protein?
So if you are considering using an amino acid supplement, this article is for you.
What are BCAAs?
BCAAs refer to the 3 amino acids; Leucine, Isolecine, and Valine. These amino acids in particular have a clear and distinct branched chain like molecular structure, which is not seen in the other 20 or so amino acids encoded in human genome.
BCAAs are proteinogenic, meaning that they are literally “protein creating”, and also occupy the highest content of amino acids contained in skeletal muscle tissue.
The benefits of BCAA supplements
Branched chain amino acids have a number of benefits, the most commonly known is their ability to trigger a myogenic pathway referred to as mTOR (mammalian target of rapamycin). The significance of mTOR for bodybuilding and muscle hypertrophy, is the equivalent of ammonium perchlorate (rocket fuel) to a rocket.
Simply put, mTOR triggers muscle protein synthesis, which is the process behind the growth of new skeletal muscle tissue.
Furthermore, BCAAs are also noted to prevent the degradation of skeletal muscle tissues during exercise, consequently helping promote post-exercise recovery and attenuate the delayed onset of muscle soreness (DOMS). Paul Jenkins MSc, author at authority sports nutrition blog, dna lean, explains;
“Exercise causes skeletal muscles to release significantly large amounts of the non-essential amino acids, glutamine and alanine. The amount released is dependent on various factors, such as exercise intensity and duration.
Nontheless, glutamine and alanine loss can soon exceed amounts available in the amino acid pool, leading to a deficit of these two amino acids. To compensate for this loss, the body catabolises muscle proteins to release the essential branch chained amino acids, leucine, isoleucine and valine.
BCAAs are then used as a substrate to synthesise the non-essential amino acids, glutamine and alanine, and thus restore the balance”
In fact this study, also confirm the same.
While BCAAs are purported to have other benefits, the above few are by far the most notable.
Related: What Are The Best Supplements For Athletes And Bodybuilders?
Should I take BCAA everyday?
Providing you are consuming an adequate intake of high quality proteins, it isn’t necessary to consume BCAAs every day. Nevertheless, consuming BCAAs on their own, prior to or during exercise is beneficial because of their muscle-sparing properties. Therefore, training frequency should primarily be the deciding factor behind the frequency of BCAA supplementation.
Limitations of BCAAs
Muscle hypertrophy is the overall balance between protein catabolism Vs protein synthesis. Thus, in order for a muscle to grow bigger, more protein tissues must be assimilated than are broken down. However, in order for muscle protein synthesis to occur, all 9 essential amino acids must be present, and in a sufficient enough quantity.
This forms the basis of BCAAs being useless on their own, because in the absence of the other essential amino acids, protein synthesis cannot occur.
What are EAAs?
EAAs is the abbreviation for essential amino acids, to which there are 9, these are:
- Histidine
- Lysine
- Methionine
- Phenylalanine
- Threonine
- Tryptophan
- Leucine (BCAA)
- Isoleucine (BCAA)
- Valine (BCAA)
Essential amino acids are referred to as being “essential” simply because the body cannot endogenously synthesis them. Thus unlike non-essential and conditionally essential amino acids, the body is reliant on EAAs being supplied from food.
Nevertheless, BCAAs are also essential amino acids. As confusing as this may sound, it’s true. This is because BCAAs have been categorised as a sub-class of essential amino acids due to their distinct structure, and are therefore referred to specifically as BCAAs.
The benefits of EAA supplements
A recent study by Robert R Wolfe revealed that muscle protein synthesis, and therefore muscle hypertrophy, cannot occur without a full complement of all 9 essential amino acids. EAAs are therefore a rate limiting factor of muscle growth. In fact, even if the mTOR pathway is triggered through the ingestion of BCAAs, in the absence of the other 6 essential amino acids, protein synthesis will simply not take place.
Because the set of 9 EAA’s include the 3 branched chain amino acids (Leucine, Isoleucine, and Valine), essential amino acids collectively, both trigger and facilitate muscle protein synthesis.
Can you take both BCAA and EAA?
BCAAs and EAAs can absolutely be taken together. In fact, the combination of branched chain amino acids and essential amino acids is optimal for any athlete or bodybuilder because mTOR is triggered and protein synthesis can then fully and properly occur.
Limitations of EAAs
Proteins are complex macromolecule structures comprised of various different combinations and sequences of amino acids. Proteins are complete structures whereas singular free form amino acids are more akin to individual building blocks that give rise to different shaped proteins.
While amino acid supplements do offer several powerful benefits, they cannot and should not be used to replace complete proteins.
Furthermore, proteins generally contain other non-essential amino acids, whereas consuming only BCAAs and EAAs, results in the body having to synthesis other amino acids itself.
Do you need BCAA If you take protein?
Fundamentally, proteins are more important than singular amino acids. While it is not necessary to supplement a diet rich in quality first class proteins with BCAAs, it is advantageous when supplementing with BCAAs prior to or during exercise.
Because amino acids are pre digested proteins they enter the blood stream rapidly, where they immediately take effect and help preserve muscle catabolism, whereas protein digestion takes significantly longer to supply the body with amino acids.
Conclusion
BCAAs consist of the three amino acids, Leucine, Isoleucine, and Valine, and are a sub-class of EAA. BCAAs are anabolic in terms of triggering the mTOR pathway, however protein synthesis is limited by the presence all 9 essential amino acids. BCAAs are also anti catabolic and are best taken pre or intra workout. Amino acid supplements should not be used in place or proteins. BCAAs and EAAs can also be used for added benefit in combination with protein supplements.
