Ask JB: Branched Chain Amino Acids (BCAA)
James,
I’ve just been reading about Branched Chain Amino Acid supplements.
Any relevance to ‘normal’ people like me?
Andy
Thanks for your question Andy! Firstly, in order to understand and examine their usefulness as a supplement, we need to take a look at what BCAAs actually are.
Branched chain amino acids or BCAAs, consist of three amino acids: leucine, isoleucine and valine. Each individual amino acid plays a role, with leucine responsible for muscle protein synthesis, isoleucine helps get glucose (and therefore energy) to cells whilst valine is a stimulant and aids muscle repair, although not much decent research has been carried out on valine in particular.
When we exercise, BCAA levels decrease in our bodies. This has a knock on increase in tryptophan and serotonin levels in the brain. These chemicals are responsible for inducing tiredness and fatigue, reducing our performance.
In light of this, it stands to reason that supplementing with BCAAs will improve performance then right?
Not necessarily.
BCAAs are already abundant in animal protein sources, so providing you get adequate levels of protein in your diet (AT LEAST 1g protein per kg of bodyweight, depending on your goals and activity level) then you are unlikely to receive any performance benefit from them and therefore there is no need to supplement with BCAAs.
There are always exceptions however! They may be of some use to people who fast, for example those doing intermittent fasting type diets, such as the ‘5:2 Diet’ or ‘Leangains’ due to the effects on increasing muscle protein synthesis, thus helping prevent muscle breakdown without calorie containing ‘food’ passing your lips!
For this purpose I would take 20g of BCAAs during the fasting window, ideally before you train, or if it’s on a non-training day then whenever suits you best.
Supplementing BCAAs at a dosage of 10-20g may help reduce fatigue and increase time to exhaustion by a small amount, but this effect most likely only occurs in untrained or novice athletes/exercisers.
Fat oxidation may also be increased when BCAAs are supplemented with. The effect however is only minor and would only have an effect on body fat reduction if we were eating in a calorie deficit, so if fat loss is your goal, focus on that first!!
A very reasonable thing to take into consideration when deciding whether or not to supplement with BCAAs is that they are very expensive, especially when taken towards the higher end of the recommended dosage, of around 20g. At the time of writing, 1kg of BCAAs costs around £40 whereas 1kg whey protein, a rich source of BCAAs costs about £15!
Finally, BCAAs taste absolutely revolting!! They tend to be sold in powder form that is supposed to be mixed with liquid. The problem is that it doesn’t mix… instead when you mix in a shaker, BCAAs don’t tend to dissolve and instead form a frothy scum at the top of your chosen liquid. Some supplement manufacturers recognise this and try to get round it by putting it into capsules or tablets but this would require taking 10-20 horse pill sized tablets per dose and further adds to the expense!
After looking at all the evidence my verdict is save your money, focus more on diet as a whole and buy yourself a nice protein- and BCAA-rich sirloin steak instead!
Source:
http://examine.com/supplements/Branched+Chain+Amino+Acids/#main_clinical_results
