Branch Chain Amino Acids (BCAA'S)

Branch Chain Amino Acids (BCAA'S)


Branched Chain Amino Acids (BCAAs) are one of the more commonly sold supplements in the entire industry, but unfortunately, in the majority of cases, the evidence fails to live up to the hype.

BCAAs are a supplement comprising of the three amino acids Leucine, Isoleucine, and Valine. Leucine is an amino acid which plays an important role in muscle hypertrophy, by assisting in the stimulation muscle protein synthesis, once a leucine intake threshold has been reached. Isoleucine is useful due to its ability to promote the uptake of glucose into muscle cells. Further evidence is needed to support how valine supports these other 2 amino acids.

The theory of BCAA consumption is that it shall promote muscle protein synthesis, prevent muscle wastage during fasting periods by inducing an anabolic stimulus, and stimulating the uptake of glucose into the muscle cell to aid performance. Let us investigate each of these claims to see if BCAAs are worth the investment.

Effects on Sports Performance and Muscle Hypertrophy

When assessing the evidence regarding BCAAs, most of it is very underwhelming. Multiple studies show that BCAAs produce zero, or negligible, improvements in blood glucose, heart rate, muscle soreness and power output.

When evaluating the effectiveness of BCAAs compared to placebo, there may be marginal increases in muscle hypertrophy and sports performance if the participants are consuming low protein diets.

When individuals consume adequate protein (with “adequate” being as low as 1.2g/kg of bodyweight), BCAAs become practically useless. Given that 1.2g/kg of BW is not a substantial amount of protein — for those looking to optimize or enhance the body composition, at least — it makes far more sense to simply increase the overall amount of protein in the diet, rather than supplementing with BCAAs.

Doing this not only ensures they accrue the benefits linked to muscle protein synthesis, but also the benefits associated with increased satiety from increased protein consumption (especially beneficial when dieting), as well as additional nutrients often found in protein rich foods which are not found in BCAAs.


The benefits of BCAAs are rendered obsolete when adequate protein is being consumed in the diet. In addition to this, they are a highly palatable source of calories which can easily be over-consumed during a dieting phase (resulting in less fat-loss than desired).

If the primary reason for consumption is to add flavour to water, then they may be an effective, albeit expensive tool. Far cheaper alternatives exist, such as sugar free cordials and other low calorie flavour enhancers.


Article written by @aaronhoey_