Branched Chain Amino Acids, better known as BCAAs are one of the most overlooked supplements out there. BCAA is a name given to the 3 amino acids Leucine, Isoleucine and Valine, these 3 are classified separately from other amino acids because they are highly prominent in muscle tissue. Considering there are around 20 amino acids, the fact that the BCAAs comprise around 14-18% of the muscles amino acid make-up gives you an idea of their importance in muscle growth and development. These amino acids are key to muscle protein synthesis, and thus muscle strength and size. Interestingly, not all of the BCAAs are proteinogenic i.e. only Leucine directly contributes to muscle protein synthesis, but Isoleucine and Valine both contribute to energy levels within muscle making them glucogenic i.e. an amino acid that can be converted into glucose via gluconeogenesis.
What makes BCAAs unique?
Granted, other amino acids are proteinogenic and could (and do) contribute to muscle protein synthesis, the difference is that Leucine (the main proteinogenic amino acid) has regularly linked with elevated muscle development in athletes. Leucine appears to be the determining factor in muscle growth, so if Leucine levels don’t meet a threshold then muscle growth seems to plateau and taper off. The addition of adequate BCAAs indirectly increase carbohydrate availability, which is why many people purport to feeling energised during a session when they consume a BCAA. A side not of this is that the body doesn’t have to then draw from the muscle for energy, consequently muscle protein is spared and all you get are GAINS!
Are BCAAs the same as protein?
Remember that all proteins are comprised of amino acids, and the wider the range of amino acids in a protein the better the proteins quality (in general). When it comes to supplementing with BCAAs, you’re giving your body the ‘building blocks’ for growth in the same way a whey protein would, only without the added lactose (carbs) and range of other, non-essential amino acids. Many whey proteins deliver roughly the same amino acid profile as milk, and this is great, but a lot of the time you won’t be getting the requisite amount of Leucine, Isoleucine and valine (BCAAs) meaning you may be limiting your growth potential.
Should you be taking a BCAA?
I firmly believe that you can get the most out of your training by combining a BCAA with a whey protein. The reason that I think many people overlook them is because they misunderstand their application, in other words, they think they are just another form of protein. Well this is understandable, but it couldn’t be further from the truth in that they both work via slightly different mechanisms. BCAAs are best consumed before exercise to minimise the catabolic (breakdown) process that is secondary to resistance training. The high Leucine levels mean your muscles potential to spring into growth is maximised after exercise…however, the growth is only possible if your total protein consumption is adequate, meaning a liquid form of protein such as whey protein is ideal within 30-60mins after your gym session.
Llewellyn, W. (2009). Sport Supplement Reference Guide. Branched Chain Amino Acids. FL: Molecular Nutrition.