Last updated on January 18th, 2019
Branched Chain Amino Acids – BCAA – are the 3 amino acids, Leucine, Iso-Leucine and Valine.
Their “branched chain” status refers to them being the only amino-acids which have a side chains of carbon atoms.
They are also three of nine “essential” amino acids, meaning that we cannot synthesize them ourselves and therefore absolutely must be gotten from food. In fact, they make up 40% of the pre-formed amino acids we (and other mammals) need.
Dietary protein contains Leucine, Isoleucine and Valine, as do complete whey protein supplements and BCAA supplements.
Another unique aspect of BCAAs is that they account for 35% of muscle proteins and can be used as raw muscle building material, direct energy transfer and as anabolic and anti-catabolic pathway signallers according to research.
They play a key role in the following processes:
- Protein synthesis – for muscle tissue growth and repair
- Anabolic and Anti-catabolic signalling pathways – chiefly Leucine which triggers the anabolic mode in conjunction with resistance training, and Isoleucine for anti-catabolic effects.
- Metabolism of glucose – for both energy and growth pathways
All of this has led us to the current state of the supplements market, where BCAA drink powders hold a virtual monopoly as “intra-workout” supplements, similar to whey protein isolate for post-workout growth, creatine for strength and citrulline malate for the muscle pump.
When you look at what branched chain amino acids do, and how much of our body is actually built from them, it’s hard to believe supplementing them is anything but mandatory for even the moderately interested bodybuilder or strength athlete.
We’re here to have a look at the hard science, and see what that says about BCAAs.
BCAAs for Muscle Building and Performance Enhancement
We’ll cut to the chase. BCAA supplements are overrated, but can be useful for training when taken at specific times.
Basically, every source of protein you eat, or drink (in the case of protein shakes) contains the 3 BCAAs. So if your diet is adequate in terms of dietary protein, your muscle growth goals will be satisfied.
However, BCAAs can be used as a direct energy source within muscle tissue itself. and it’s a relatively short time frame from ingestion to utility. This has caused BCAAs to become the intra-workout (during training) supplement du jour.
That’s the performance enhancement aspect covered.
Additionally, Leucine and Isoleucine are signallers, or triggers, for specific processes. Leucine, in combination with the mechanical action of muscle contractions, signals the mTOR anabolic pathway to kick into a higher gear, and increases insulin secretion for higher metabolic turnover of glucose.
Isoleucine has a lesser impact than Leucine in terms of accelerating muscle protein synthesis, but does increase glucose uptake and use its usage as a source of fuel during exercise.
Valine appears less important than the other two because unlike leucine and isoleucine it does not seem to provide benefits in isolation.
More studies are required with Valine in isolation and combination with the others to determine its true benefit.Did you know: The 3 Branched Chain Amino Acids can be used as a direct fuel source inside muscle tissueClick To Tweet
How To Use BCAAs
As mentioned earlier, it comes down to timing. The only reason to supplement BCAAs as opposed to a complete protein shake, which would contain them anyway, is because it’s tough to stomach a complete protein shake immediately prior to, and/or during, intense exercise.
With that in mind, a BCAA specific product is useful as a pre-workout, or as part of you pre-workout drink, and as an intra-workout drink.
Aerobic exercise sessions or endurance sports lasting longer than 2 hours are a situation where you can take periodic sips of a BCAA mix as you go.
However, it should be noted that between 5 grams and 10 grams of BCAAs together with long distance endurance training/performing can induce stomach disturbances.
Dosage depends on your goal.
Leucine is the most important one of the 3, which is why you will find different ratios in different products. Some supplement companies are using a traditional 2:1:1 ratio of leucine to isoleucine to valine. Others are using a 12:1:1 ratio.
Isoleucine is important too but if it’s half of the Leucine dosage then that’s fine.
Valine – again, we don’t really know how useful valine is but deficiency is certainly a problem, which is why it’s just thrown in to BCAA supplements, and usually at equal weight to isoleucine.
BCAA Side Effects
Too much can upset your stomach. Emergency toilet breaks are not conducive to a decent workout.
Between 10 grams and 20 grams is where this might start happening, especially if you are doing an intense session.
For the limited additional benefit you’ll get, it’s not worth the drama of stomach ache halfway through a set of squats.
If you are more on the novice end of the gym scale then supplementing with branched chain amino acids will have a greater effect than if you are a veteran. Why? Because you are more likely to need the anti-fatigue / direct energy benefit.
Supplement manufacturers sell BCAAs and protein hard, because of the profit margins. If you get a lot of natural protein in your diet then this is by far and away the best source for your body.
Timing is a small factor if your system is enriched with a complete protein profile.
They are vital, no-one is saying different, but you might be able to do without a separate supplement dedicated to BCAAs.
If your pre-workout supplement contains them, then that’s probably good enough combined with your diet and protein shakes.