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The Importance of BCAAs

BCAAs, or Branch Chain Amino Acids are a becoming more and more popular in the fitness industry. They were never a supplement of choice for me starting off, admittedly I didn’t know much about them until I reached my twenties and hence refused to take them. Ironically, BCAAs are now the one thing I wont leave my house without. BCAA powders are generally made from three essential amino acids called Leucine, Isoleucine and Valine that scientists have been combining for years in a 2:1:1, 4:1:1 or even 8:1:1 ratios to supplement the high protein diet of athletes and/or gym goers. BCAA supplements are basically small molecules that make up protein. Including them in your diet in this free form has been shown to help promote muscle mass, recovery and support the immune system during periods of intense training.


Making sure we get adequate amounts of amino acids is difficult for those of us who exercise regularly. Exercise burns amino acids rapidly and failure to replenish the body with proper amino acids can cause people who work out vigorously to make little or no progress. The important thing to note here is that BCAAs do not require digestion and therefore go almost immediately into the bloodstream and can be used faster by our muscle cells.


What are the functions of BCAAs?

Not a lot of people know this but BCAAs act as nitrogen carriers, assisting the muscles in synthesizing other amino acids that are needed for anabolic muscle action. Basically, it combines simpler amino acids to form a complex of whole muscle tissue [1]. Therefore BCAAs actually stimulate the production of insulin to some degree, allowing circulating blood sugar to be taken up by the muscle cells and used as an energy source. In addition to this, that same insulin response promotes amino acid uptake by the muscle.


BCAAs are both anabolic and anti-catabolic because of their ability to significantly increase protein synthesis, facilitate the release of hormones such as growth hormone (GH), IGF-1, and insulin, and help maintain a favorable testosterone to cortisol ratio [1].


As mentioned above, BCAAs are an excellent anti-catabolic. They help prevent protein breakdown and muscle loss, significantly important to most of us who exercise, from the average gym-goer to those on pre-contest diets. During times of low caloric intake, the use of BCAAs is strongly recommended because there is an increased risk of muscle loss due to a decrease in the rate of protein synthesis and an increase of proteolysis, Proteolysis for those of you who don’t know is the hydrolytic breakdown of proteins into simpler soluble substances such as peptides, amino acids etc. that occurs during digestion [3].

Biochemistry behind BCAAs

To delve a little deeper into the three essential amino acids that make up BCAAs in the required ratios, 2:1:1, 4:1:1 and 8:1:1 (I’ve even seen 16:1:1, which is ridiculous, by far the most optimal in my opinion is 4:1:1) I have put my biochemistry hat back on to go into a little more detail for those of you like myself who are keen to get down to the molecular level:



Valine is an aliphatic amino acid that is quite closely related to both leucine and isoleucine in structure and in function. These amino acids are extremely hydrophobic (the opposite being hydrophilic) and are therefore almost always found on the interior of proteins peptides. Valine molecules are seldom useful in routine biochemical reactions, but are extremely important in determining the three-dimensional structure of proteins due to their hydrophobic nature [6]. Important food sources that contain valine include soy flour, cottage cheese, fish, meats, and vegetables. Valine is incorporated into proteins and enzymes at the molar rate of 6.9% when compared to the other amino acids [4].




Leucine, like its structural cousin's isoleucine and valine, is also a hydrophobic amino acid that is found as a structural element on the interior of proteins and enzymes. There appears to be no other significant metabolic role for these amino acids, but they are essential and because they are not synthesized by mammalian tissues and must be taken in via the diet [4].


Leucine ties with glycine for the second most common amino acid found in proteins, 7.5% on a molar basis compared to the other amino acids [2]. Leucine provides ingredients for the production of other essential biochemical components in the body. Some of these are utilized for the production of energy or stimulants to the upper brain and therefore helping you to be more alert [5].




As with valine and leucine, isoleucine is a member of the aliphatic side-chain amino acid family that is composed of extremely hydrophobic biochemicals that are found principally in the interior of proteins and enzymes. The take away message here is like with any essential amino acids, isoleucine is not synthesized by mammalian tissues and therefore is vital that we get ENOUGH of this in our diet [4]. Sometimes amino acids that we supplement are also made by mammalian tissue and therefore we can sometimes get away with not looking after them so much in our diets. This is not the case here and makes BCAAs supplementation even more crucial.  


Similarly to both valine and leucine they appear to have no other significant biological role than incorporation into proteins and enzymes, where their main purpose is to help dictate the tertiary structure of the macromolecules [5].


Isoleucine is incorporated into proteins at a molar rate of 4.6% when compared to the other amino acids [6]. Isoleucine contains ingredients for the manufacturing of other essential biochemical components in the body, some of which are utilized for the production of energy (ATP), stimulants that cross the blood-brain barrier and helping you to stay more alert for longer [7].



When Do You Take BCAA Supplements?

This is something I get asked everyday and the quick answer is “all the time”. There is no time of the day that taking BCAA’s is a bad idea, AT ALL. When is it most optimal? Well, immediately before, during or after training. Believe it or not after training is just as important as before and during exercise. We have a window post exercise in which your muscles need protein to repair and regrow. Research shows that solely relying on a protein shake alone isn’t enough to put significant levels of amino acids into your blood stream. This is because the digestion rate of the protein takes time. BCAA supplements help put amino acids into the body quickly and work with the fully digested protein to enhance the entire recovery process.



How Can You Avoid Breakdown?

I make sure to take BCAAs to increase the rate of protein synthesis after I train, making sure gains are made from each and every workout. Evidence? Well, a study in the journal Medicine and Science in Sport and Exercise found that BCAA supplementation could contribute to an anabolic environment in the body. More importantly which answers a big question I get asked: there is evidence to suggest that there is a dose-dependent response to BCAAs, i.e. meaning the more you take the better the results. For a lot of you athletes, another great reason to take BCAAs is if for some reason you take time off due to an injury, this supplement will limit the amount of muscle loss and fat gain over that period of time. A study done by the European Journal of Applied Physiology found that after giving BCAAs to rats with their hind limbs immobilized actually helped preserve protein synthesis that regulates muscle growth. The moral of the story is that BCAAs sacrifice themselves as fuel in order to preserve muscle in the body, training or not, a high level of BCAAs in your system can do nothing but help your overall body composition.




In the fitness world the supplement industry is huge. Everyone claims to have the next cutting edge product that will make you a super human. The real truth is there are no fast secret to success, only hard work, solid nutrition and a smart approach to supplementation. If BCAAs are not part of your nutrition/supplement stack, you need to have room made for them. No question. Other than creating a fuel source for your body and preventing muscles from breaking down that little bit faster than they need to, BCAAs can help stimulate fat loss, and help you get back in the gym after an illness quicker than expected.


 If you are serious about your training and desperate to get results get yourself some BCAAs and GAURENTEE you will not be sorry!

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  1. Blomstrand et al., Influence of Ingesting a Solution of Branched Chain Amino Acids on Perceived Exertion During Exercise, Clin. Sci.:87, 52, 1994.

  2. Goldberg, A., The Regulation and Significance of Amino Acid Metabolism in Skeletal Muscle, Fed. Proc.: 37, 2301, 1978. [

  3. Goto, Masaru; Miyahara, Ikuko; Hayashi, Hideyuki., Crystal Structures of Branced-Chain Amino Acid Aminotransfease Complexed with Glutamate and Glutarate: True Reaction Intermediate and Double Substrate Recognition of the Enzyme. Biochemistry (American Chemical Society) v. 42 no. 14 (April 8 2003) p. 3725-33.

  4. Mero A, et al. Leucine supplementation and serum amino acids, testosterone, cortisol and growth hormone in male power athletes during training. J.Sports Med Phy Fitness 1997:37(2):137-45

  5. Nellis, Mary M.; Doering, Christopher B.; Kasinski, Andrea. Insulin increases branched-chain a-ketoacid dehydrogenase kinase expression in Clone 9 rat cells. American Journal of Physiology v. 283 no. 4 (October 2002 pt1) p. E853-60.

  6. Plaitakis et al., Pilot Trial of Branched-Chain Amino Acids in Amyotrophic Lateral Sclerosis, Lancet: i., 1015, 1988.

  7. Riazi, Roya; Wykes, Linda J.; Ball, Ronaold O. The Total Branched Chain Amino Acid Requirement in Young Healthy Adult Men Determined by Indicator Amino Acid by Use of L-(1-13C) Phenylalanine. The Journal of Nutrition v. 133 no. 5 (May 2003) p. 1383-9.

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