Amino Acid Supplements Explained


Amino acids are the building blocks of muscle-building protein - but what are the best sources for them and are you getting enough?

Sam Rider
19 Jan 2015

Ah, protein. Giver of life, maker of muscles. It's easy to lump every source - powder, meat, yoghurt, that weird water that cottage cheese comes in - as the same thing, but in reality, not every protein is created equal. The key? Amino acids, the building blocks of life. And knowing what you're getting - and what you aren't - could be key to your progress inside the gym. 

The essential mix

There are two types of amino acids: essential and non-essential. 'Essential' amino acids can't be synthesised by your body, so they have to come via food – for anyone taking notes, they include isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan and valine. Non-essential amino acids can be synthesised by our body - and so they aren't quite as important. These include glutamate, alanine, aspartate, glutamine, arginine, proline, serine, tyrosine, cysteine, taurine and glycine. Got that? Well done.

Before you learn the amino acid memory song (no, not really), a couple of caveats. Firstly, histidine's status as the ninth essential amino acid is hotly debated, because the body occasionally struggles to make sufficient amounts. Secondly, the definition of non-essential amino acids is oversimplified. Often, the body has the potential to manufacture them but environmental factors, such as being exposed to large quantities of toxins and pollutants, can inhibit the body's ability to produce them. Therefore, it's wise to consider all the amino acids as equally important and worth finding space for in your diet. 

Below we've explained the supplements and food sources that will help you keep your amino acid levels up.

Whey protein

Will supplements help?

Most whey protein shakes will include several of the 21 amino acids mentioned above but three are especially worth remembering when physically training. Leucine, isoleucine and valine are the only ones defined as BCAA (branched-chain amino acid).

Crucially, they are the only ones that are oxidised for energy during exercise, nullifying their highly anabolic (muscle-building) qualities. That's why taking BCAA supplements when training can have such positive effects. Together, these three essential amino acids can comprise up to one-third of your total muscle protein.

What do BCAAs do?

The theory is that they can help prevent the breakdown of muscle tissue during intense exercise. They also increase the release of human growth hormone.

Who should take them?

‘BCAAs should be taken by anyone who weight trains,’ says strength coach Gregg Marsh, ‘preferably in capsule form rather than tablet or liquid.’ There's little evidence that BCAAs will improve performance among endurance athletes, though, and unless you’re training seriously hard it’s possible you can get enough BCAAs from a recovery drink to make a separate supplement unnecessary.

How much should I take?

‘Anything less than 20 capsules per workout is a waste of time,’ says Marsh. ‘Many professional rugby and football clubs have seen huge improvements in performance, using 40 caps of BCAAs every workout.’ Nutrition expert Anita Bean is more conservative: 'Doses of 6-15g may help improve your recovery during hard training periods.'

When should I take them?

‘They have positive benefits before, during and after a workout,’ says Marsh. ‘Studies have shown that taking BCAA supplements during and after exercise can reduce muscle breakdown, while taking them before resistance training reduces delayed onset muscle soreness [DOMS].’ They might also be beneficial if taken last thing at night - but the evidence here is sketchier.

Taking BCAAs before exercise causes the breakdown of leucine, isoleucine and valine in the liver, directing it to your muscles for muscle protein synthesis. Just make sure you don’t train on an empty stomach or you may experience some discomfort. The best combination is to ingest BCAAs before and during exercise, followed by whey protein after the gym session. 

On page two find out if amino acids will help with recovery, what foods you'll find them in and how vegetarians can make sure they get enough.

This content is from the experts at Men's Fitness magazine.

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