Written by Simon Cushman
Should I Be Consuming BCAAs?
Energy balancing is not only a hard concept to grasp, but even harder to put into practice, especially with the amount of advice being put up on the internet and some of the tests required to measure the likes of resting metabolic rate and movement efficiency.
If energy is in a negative balance, you will lose energy stores in one form or another. This will start with fat and carbohydrate metabolism but can also reach to the breakdown of muscle tissue, and in turn, liberate amino acids to be used as energy (catabolism) in a calorie deficit.
Catabolism will lead to a lower movement metabolism, so you will burn fewer calories when using your body, and also lead to a lower rate of protein synthesis (Apro & Blomsrad, 2010). This means that basically, you won’t build as much muscle, AND you will be losing a small percentage of muscle at the same time.
Why Use BCAAs?
During and after resistance training your body automatically triggers different messenger molecules that convey information to specific cells from DNA and help your muscles to adapt to a training stimulus (Phillips, 2014). These processes can be adapted to the type of training you undertake including the intensity and duration of your session as well as your nutrition around training (Schoenfeld, 2010).
The relative concentration of branch chain amino acids (BCAA) in the human body is relatively small compared to the proportion of muscle mass we have (Shimomura et al., 2006).
It would appear that after resistance training, this concentration of BCAA increases, suggesting a catabolism of muscle tissue in response to the external load, it is accepted that after supplementing with BCAA, the concentration increases naturally and doesn’t increase to the same extent post resistance training (Blomstrand, 2006). This has led to the belief that BCAA reduces the catabolism of resistance training in a multi-faceted way.
What Are BCAAs?
Branch chain amino acids (BCAA) are made up of the amino acids; leucine, isoleucine and valine. They can help change the protein pathway around workouts by increasing the amount of mTOR and decreasing the amount of mRNA (two messenger molecules to synthesise or break down muscle tissue respectively) (Apro & Blomstrand, 2010; Blomstrand, et al., 2006).
In particular, leucine is heralded as offering the anabolic and anti-catabolic benefits and is also partially converted into HMB which leads to a prevention of muscle catabolism (Mero, 1999). If using BCAAs can provide a building and protective mechanism for muscles you may effectively be able to use these as an alternative to whole source protein to see a similar effect, thus lowering your calorie intake while still maintaining muscle and performance and increasing lipid oxidation (Gualano et al., 2011).
Recent research found that young women (age 21-24) suffered significantly less muscle soreness the day after a squat protocol when BCAA was consumed immediately prior (Shimomura et al., 2006). Further to this, an increase in protein uptake in women when on a calorie restricted diet stabilised blood glucose and reduces the effects of a meal on insulin response (Layman et al., 2001). This was linked to an increase in blood BCAA concentration in the protein group.
In a performance setting, the use of BCAA is suggested to reduce the effects of mental fatigue from a training session or a 30 km cross-country race by reducing the uptake of tryptophan by the brain (Gualano et al., 2011; Blomstrand, 2006).
Now the heavy stuff is out of the way, what will it mean for you…? Well; the main effect of BCAA seems to be on a calorie controlled diet when there is a need to preserve muscle and promote protein synthesis. This will help to burn through more fat during exercise and maintain muscle mass and strength.
BCAA is also useful to use during periods of intense training or those lasting more the 45 min especially when mental fatigue might set in during a match or competition (or even a team meeting).
While BCAA's are found in protein sources, these can differ substantially in amounts depending on the sources you use. It is therefore recommended to supplement with BCAA to maintain blood concentrations and promote lean muscle gain and fat loss while on a calorie-controlled diet.
Using BCAA immediately prior to or during training has a positive effect on training performance and metabolism. Coupled with the ingestion at least once more per day seems to yield the best results in protein synthesis and body composition.
Check out our favourite BCAA recipes:
Apro, W. & Blomstrand, E. (2010) Influence of supplementation with branched-chain amino acids in combination with resistance exercise on p70S6 kinase phosphorylation in resting and exercising human skeletal muscle. Acta Physiol. 200. 237-248.
Blomstrand, E. (2006) A Role for Branched-Chain Amino Acids in Reducing Central Fatigue. Journal of Nutrition. 136. 544-547.
Blomstrand, E., Eliasson, J., Karlsson, H. & Kohne, R. (2006) Branched-Chain Amino Acids Activate Key Enzymes in Protein Synthesis after Physical Exercise. Am Soc for Nutr. 136. 269-273.
Gualano et al. (2011). Branched-chain amino acids supplementation enhances exercise capacity and lipid oxidation during endurance exercise after muscle glycogen depletion. J Sports Med Phys Fitness. 51(1). 82-88.
Mero, A. (1999) Leucine supplementation and intensive training. Sports Med. 27 (6). 347-358.
Philips, S. (2014) A Brief Review of Critical Processes in Exercise-Induced Muscular Hypertrophy. Sports Med. 44. S71-77.
Schoenfeld, B. (2010) The mechanisms of muscle hypertrophy and their application to resistance training. J Strength Cond Res. 24 (10). 2857-2872.