Photo: Geoff Kabush takes down a Roctane Energy Gel, which delivers almost 1.5 grams of amino acids.
What is the big deal with BCAAs anyway? You may have heard a thing or two about them from your supplement-savvy training partner, but unless you have a background in biochemistry, you might not know why they matter or how to incorporate them into your training and nutrition regimen.
Why Do BCAAs Matter?
Leucine, isoleucine, and valine are the three branched chain amino acids (BCAAs), so named because of their nonlinear (“branched”) carbon atom configuration. Amino acids are the building blocks of proteins, and proteins, as you probably know, make up the structure of the body. Amino acids are either produced in the body (termed, “nonessential”), or they must be supplied from the diet (termed, “essential”).
What Makes Them ‘Essential’
BCAAs are essential amino acids, meaning they are not made in the body, yet they constitute more than one third of the protein found in human muscle tissue! Rich dietary sources of BCAAs include dairy, egg, meat, poultry and fish. Supplemental BCAAs are also widely available and often used within the context of sports nutrition. BCAAs are unique because, unlike most other amino acids, they are primarily metabolized within the muscle itself, as opposed to being broken down by the liver. That has two important implications for performance:
- Rapidly Absorbed: BCAAs enter the bloodstream rapidly, bypass breakdown in the liver, and are readily taken up by active tissues (mainly muscle), and
- More Fuel: BCAAs provide an additional fuel source for working muscle, as BCAA breakdown for energy increases during prolonged exercise (Shimomura et al., 2006). BCAAs also play an important role in overall protein turnover, which is to say they help regulate whether the body is in a recovery (tissue building) or catabolic (tissue breakdown) state.
Of the BCAAs, leucine in particular has been shown to initiate muscle protein synthesis (building) and inhibit protein breakdown (Norton & Layman, 2006). This is key whether you are trying to build muscle, maintain lean body mass during caloric restriction, or simply reduce muscle breakdown during intense and/or long-duration exercise.