BCAA’s, Leucine and Its Anabolic Trigger

by DeanMcKillop 8060 views Supplements

BCAA’s, Leucine and Its Anabolic Trigger

We have all seen them, probably tasted them and then often asked ourselves why we even use them, but BCAA’s are fast becoming one of the top selling supplements on the market. Touted as being a recovery product, BCAA’s or less commonly referred to as, Branched Chain Amino Acids, are a combination of 3 essential amino acids that are responsible for muscle growth and repair, glucose uptake and nervous system support.

So what do BCAA’s really do and who will benefit most from them?

The top 2 promoted benefits of using a BCAA supplement are:

Muscle Protein Synthesis stimulation
Reduced risk of muscle loss

Layne Norton is probably one of the most notable promoters of BCAA’s, but more specifically Leucine, with his research focusing on the effects of Leucine on protein metabolism. In a study on adult rats in 2012, Layne Norton and his team of researches concluded that the dietary consumption of Leucine in a meal, or in this case a BCAA product, was one of the primary determinants for achieving maximum muscle protein synthesis (MPS) (1).

In doing so, the researches found that MPS could only be stimulated every 4+ hours from a complete protein source (Food and Whey Protein), as opposed to the commonly suggested 3 hour feeding recommendation. Despite this finding, further research indicated that the consumption of a Leucine rich BCAA formula allowed for mid refractory MPS to be achieved as well.

But what does this all mean?

Well, you can think of MPS as an indicator for a muscle growth response that is maximised by nutrient consumption and the individual’s genetic potential. You can also stimulate an MPS response with exercise, but for the purpose of this article I will solely be referencing amino acid supplementation.

Now, with the primary goal being muscle growth, an individual looking to optimise this should attempt to achieve as many maximal MPS responses in a day as possible, of which it can only be achieved through the consumption of more than 2.5-3g of Leucine in a meal when consumed alongside other amino acids.

Which, when you consider the impossibility of eating a whole protein source during training, utilising an amino acid supplement is a great addition to training nutrition.

muscle protein breakdown

When looking at exercise and its effects on MPS, it is also important to consider MPS in the context of Muscle Protein Breakdown (MPB) as well, as the net gain or loss of muscle protein is the primary determinant for whether an individual is anabolic or catabolic by nature. What research shows, is that, consuming an amino acid supplement around training reduces MPB while stimulating MPS (2,3). Furthermore, the addition of amino acids in the pre, intra or post workout phase, leads to a greater duration of MPS signalling as well (4).

Essentially, a BCAA supplement may help you breakdown less muscle protein and while stimulating more protein synthesis!

You lose less muscle and grow more… awesome.

But that’s not all BCAA’s are good for either.

Perhaps even more interesting is the effect BCAA’s have on perceived mental and physical fatigue, as well as their ability to enhance performance when consumed around training, especially when combined with other synergistic amino acids.

In a review of more than 300 pieces of literature, Salinas-Garcia et al (2014) concluded that within 14 relevant studies on BCAA supplementation and their effect on performance, that BCAA’s, specifically in a 2:1:1 ratio (Leucine:Iso Leucine:Valine), resulted in a reduction of perceived pain, perceived mental fatigue and a reduction in perceived exertion.

Similarly in two comparative studies looking at the effects of simultaneous BCAA and Arginine supplementation around exercise, found that athletes consuming BCAA’s + Arginine performed better in repeat bout efforts than their counterparts who were given no BCAA formula (6,7).

BCAA’s help with preventing muscle loss, more so in times of insufficient protein intake and they enhance performance via the reduction in perceived mental and physical fatigue.

So whether you are looking for performance enhancement or you are attempting to ensure muscle growth and repair are optimised in times of need, BCAA’s may be a great addition to your supplement regime.

It is important to note that the efficacy of BCAA supplementation on muscle growth becomes far more apparent in individuals who are lacking an adequate amount of protein intake from their diet, however their perceived benefits on performance are extremely promising.

For maximum benefits, combine your BCAA’s with Citrulline Malate and consume either pre or during your workout, as this combination will provide both the anti-fatigue effects of BCAA’s and Citrulline Malate, but Citrulline Malate will also enhance blood flow and has great literature on performance as well. 

Recommended Products

Citrulline Malate By Gen-Tec Nutrition

Gen-Tec Nutraceuticals source, blend and package 100% pure pharmaceutical grade Citrulline Malate powder and is ideal for individuals with a goal of incresing endogenous Nitric Oxide levels.

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Revive by Genetix Nutrition

Revive is an advanced BCAA formula and is sugar free. It mixes easily and tastes great. It has been formulated to maximize training intensity and promote optimal muscle protein synthesis whilst you train.

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Norton, L., Wilson, G., Layman, D., Moulton, C. and Garlick, P. (2012). Leucine content of dietary proteins is a determinant of postprandial skeletal muscle protein synthesis in adult rats. Nutrition & Metabolism, 9(1), p.67.

Atherton, P. and Smith, K. (2012). Muscle protein synthesis in response to nutrition and exercise. The Journal of Physiology, 590(5), pp.1049-1057.

Tang, J. and Phillips, S. (2009). Maximizing muscle protein anabolism: the role of protein quality. Current Opinion in Clinical Nutrition and Metabolic Care, 12(1), pp.66-71.

Pennings, B., Koopman, R., Beelen, M., Senden, J., Saris, W. and van Loon, L. (2010). Exercising before protein intake allows for greater use of dietary protein-derived amino acids for de novo muscle protein synthesis in both young and elderly men. American Journal of Clinical Nutrition, 93(2), pp.322-331.

Salinas-Garcia, M.E., et al. (2014). Effects of branched amino acids in endurance sports: a review. Nutricion Hospitalaria 31(2), pp 577-589.

Chen, I., Wu, H., Chen, C., Chou, K. and Chang, C. (2016). Branched-chain amino acids, arginine, citrulline alleviate central fatigue after 3 simulated matches in taekwondo athletes: a randomized controlled trial. J Int Soc Sports Nutr, 13(1).

Chang, C., Chang Chien, K., Chang, J., Huang, M., Liang, Y. and Liu, T. (2015). Branched-Chain Amino Acids and Arginine Improve Performance in Two Consecutive Days of Simulated Handball Games in Male and Female Athletes: A Randomized Trial. PLOS ONE, 10(3), p.e0121866.



Exercise Scientist

I completed my Exercise Science Degree at the University of QLD and have worked in the fitness industry for over 8 years, including a short stint at the Brisbane Broncos in 2010 as a student. I also hold my Level 2 Strength and Conditioning Coach accreditation (ASCA) and have competed in 1 bodybuilding season, placing 2nd at the IFBB u85kg Nationals.

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