The branched-chain amino acids (BCAAs) include the three main amino acids – valine, leucine and isoleucine – which help prevent the breakdown of your cells. When taken with exercise they reduce muscle soreness and lessen mental fatigue and in doing so boost your immune system.

However, unlike most amino acids, which are the building blocks of protein and metabolized in the liver, BCAAs are directly metabolized in your skeletal muscle. Yes, that’s right, in the heart of your biceps. That means they’re most potent when taken during exercise, when muscle glycogen levels are low and your body can burn them for energy.


They’re everywhere

On average, the whole foods you consume, such as chicken, beef and fish, already contain 15–20% BCAAs per 100g. Whey has 23–25% BCAAs per 100g, while casein sports 18–20% BCAAs per 100g.

Having read that, you might think it means supplementing with BCAAs is unnecessary, given you’re probably getting enough in your pre-workout shake. However, they are most beneficial prior to and during exercise because they won’t leave you feeling too full to do cardio exercise.


Don’t get too much of a good thing

The benefits of BCAAs are numerous – including muscle retention, reduced soreness, reduction in perceived effort during exercise, abating the reduction of testosterone while training and muscle protein synthesis.

However, consuming too much of them can elicit ammonia production which leads to fatigue.

The upper threshold appears to be 136mg/lb or 300mg/kg of bodyweight. So taking any more than this might see you slumped over the treadmill rather than running on it. Save your cash and ration them out.


optimum nutrition bcaa tub


Watch your ratios

Sometimes you’ll see some BCAA supplements which exceed the science-backed ratio of 2:1:1 for leucine, valine and isoleucine. That’s because leucine is the key activator of protein synthesis.

But that doesn’t mean taking more leucine is good for you. In fact, an increase in leucine without an increase in the other two could result in a decrease in protein synthesis.

Take home message: give these supplements a wide berth and stick with those that offer the 2:1:1 ratio.


Absorb more with B6

Vitamin B6 is critical for the proper utilization of BCAAs because your levels of this vitamin actually get diminished when you consume too many BCAAs.

It is worth noting that taking in too much B6 vitamin can also have adverse effects – except when consumed from food sources such as sunflower seeds, pistachio nuts, fish, bananas and avocados.

This doesn’t mean you should try to increase your intake of these foods. Rather, avoid taking too many BCAAs in the first place as that can cause fatigue and decrease your levels of important nutrients. Less is more.

There’s no denying the benefits of supplementing with BCAAs. However, most studies use participants who are protein-deficient so their benefits tend to be more pronounced than they would be for a normal person.

So if you are taking in enough protein already, you won’t need them as much as a person who is dieting for fat loss. But, again, that doesn’t mean BCAA supplements aren’t useful if you’re dieting, or before and during training, because there’s a place for everything and everything in its place.


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