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BCAAs are everywhere. Powders,
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pre-workouts, energy drinks, and
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depending on who you ask, they're either
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essential for muscle growth or
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completely overrated. Let's talk about
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>> In this video, I'll explain what
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branched-chain amino acids are, what
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they do in the body, how they relate to
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muscle growth and recovery, and whether
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you actually need to supplement them.
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So, what actually are branched-chain
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amino acids? Well, protein is made up of
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amino acids, and of the 20 amino acids
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used by the human body, nine are
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essential, meaning we have to get them
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from our diet. Three of those essential
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amino acids are known as branched-chain
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amino acids or BCAAs.
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Leucine, isoleucine, and valine. These
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are called branched-chain amino acids
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because of their chemical structure, as
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they've got branches coming off from the
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center of the amino acid. More
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importantly, they play a big role in a
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lot of different processes around the
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body, like protein metabolism, muscle
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tissue signaling, insulin and energy
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regulation, and nervous system function.
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BCAAs are absolutely essential nutrients
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that your body needs to function
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properly. The real question is whether
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you need to take BCAAs as a supplement.
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First, let's talk about how muscle
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growth works and where leucine, one of
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those BCAAs, fits in. Your muscle mass
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is constantly being regulated by two
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opposing processes. On one side, you've
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got muscle protein synthesis or MPS,
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which is building muscle. And on the
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other side, you've got muscle protein
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breakdown or MPB, which is breaking
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muscle [music] down. If muscle protein
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synthesis is greater than muscle protein
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breakdown, over time, muscle grows. Now,
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two main things stimulate muscle protein
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synthesis. The most important signal, by
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far, is resistance exercise. Without
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that initial signal from exercise,
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muscle has no reason to grow. The second
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important signal is eating protein. And
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this provides both a signal and the
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building blocks needed to build new
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[music] muscle tissue. One of the BCAAs,
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leucine, plays a really important role
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here. Leucine acts as a trigger for
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muscle protein synthesis by activating a
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key signaling pathway called mTOR that
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helps start the muscle building process.
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You can think of leucine as the switch
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that turns muscle protein synthesis on.
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But, and this is a really important
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point, leucine on its own does not build
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muscle. Once muscle protein synthesis is
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switched on, your body still needs all
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the essential amino acids to actually
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build new muscle tissue. Without them,
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the whole process quickly comes to a
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halt. So, while BCAAs, especially
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leucine, are essential for signaling,
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they're not enough for muscle growth on
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And this is why having a high protein
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diet is so important for building
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muscle. So, do you need to take [music]
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BCAA supplements to get this effect?
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This is where a lot of the confusion
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comes in. If leucine and other BCAAs
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help trigger muscle protein synthesis,
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does that mean you need to supplement
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BCAAs directly? For the majority of
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people, the answer is no. Because if you
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already have plenty of high-quality
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protein in your diet, you're already
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getting plenty of BCAAs. Proteins like
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whey, milk, meat, fish, eggs,
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microprotein, and soy naturally contain
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all three BCAAs, including a high dose
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of leucine. And they all contain all the
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other essential amino acids needed for
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muscle growth. And even if you're
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consuming a lower-quality protein like
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rice protein, for example, all you need
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to do is eat more of it to get all the
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essential amino acids that you need for
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building muscle. So, when you eat enough
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protein, you're getting the signal to
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start muscle protein synthesis and the
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raw materials needed to actually build
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muscle. This is why studies consistently
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show that taking enough protein, like
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whey, milk, or soy around training, has
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the following effects. It strongly
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stimulates muscle protein synthesis and
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it supports muscle repair and recovery.
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There is a lot of research to show that
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BCAAs help stimulate muscle protein
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synthesis and recovery, but in practical
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terms, you can get the same effect, or
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even better effects, actually, just by
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eating enough high-quality protein. This
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doesn't mean BCAAs aren't important.
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They are essential amino acids with key
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roles in muscle growth.
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But, it does mean that for most people,
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you're getting all the BCAAs you need
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through a normal high-protein diet,
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without the need to take a separate
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supplement. So, that begs the question,
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when might BCAAs be useful? Well, there
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might be a couple of situations where
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BCAA supplementation could make sense.
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The first one is if someone struggles to
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eat enough protein overall, or per meal.
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Adding BCAAs could help stimulate muscle
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protein synthesis, but increasing their
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total protein intake would usually be
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the most effective approach. The second
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case would be if someone had a
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relatively low intake of lower-quality
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proteins. Some plant-based proteins, for
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example, are lower in leucine and
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certain essential amino acids. In these
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cases, adding leucine, or BCAAs, could
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help enhance the muscle protein
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synthesis response. But, again,
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increasing the total protein that person
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is eating, even if they are
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lower-quality proteins, would help them
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get enough BCAAs. And finally, during
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prolonged endurance exercise, like
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cycling or running, adding BCAAs to a
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carbohydrate drink may help to reduce
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markers of muscle damage, and to reduce
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Although, the same could be achieved by
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adding some extra protein to a
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carbohydrate drink, too. So, what's the
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BCAAs are essential amino acids that
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play important roles in muscle
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metabolism. For most people, if you get
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enough protein, spread across meals and
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around training, that'll provide all the
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BCAAs you need [music] to support muscle
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growth and recovery. There are a couple
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of situations where BCAA supplements
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could theoretically be useful, like when
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protein intake and protein quality are
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But, increasing protein intake would be
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the best way to deal with that. So,
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All you need to know about BCAA
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If you have any questions, drop them in
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the comments below, and remember to like
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and subscribe to Myprotein YouTube
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channel for more great, evidence-based
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nutrition information.
