EAA’s VS BCAA’s: The Truth About Amino Acids

EAA’s VS BCAA’s: The Truth About Amino Acids

Attachment 76802

When we think intra-workout supplementation, we often find ourselves thinking BCAA, BCAA, BCAA, but what about Essential Amino Acids (EAAs)? For years we’ve been led to believe that BCAAs are all you need for intra-workout supplementation, but research shows that isn’t the case [1].
BCAA use has been promoted in various manners:

All day sipping, which turned out to blunt MPS (muscle protein synthesis) signaling. This is counterproductive to muscle growth and recovery, and thus should not be promoted as a way to flavor your water.
Intra-workout usage. This is not helpful since it takes all of the EAAs to reap the benefits of intra-workout use (see article below).
Using BCAA’s between meals to signal muscle protein synthesis. This would be beneficial for those in a caloric deficit as an “anti-catabolic” agent, but once again does not work (see reference 1). Dieter et al. (2016) found that the usage of BCAAs does not lead to an increase of fat-free index in those dieting while supplementing with BCAAs [1]. This is a finding consistent with lots of BCAA studies [2].

Essentially BCAAs are not the Holy Grail we’ve been led to believe by supplement companies.
What does Leucine do?

Leucine itself is a tricky beast. Leucine can increase MPS by 30%. Leucine, in theory, works because it is a rate-limiting step in protein synthesis. By supplementing Leucine, you get around the rate-limiting step. Rate limiting step, in this case, refers to the means in which a process is limited (i.e. without more leucine, MPS rates are limited). This is due to an intracellular anabolic signaling, which is increased when leucine is supplemented. Leucine, however, is not the only important component of this process as it does require the other Essential Amino Acids to work best. A major limitation in these studies is that in humans skeletal muscle is a small amount of your total body mass [2].
What about EAA’s?

A 2011 study performed by the US military (meaning these are very fit individuals) studied the effects of EAA supplementation during endurance exercise; they were interested to see the effects of EAA supplementation on postexercise skeletal muscle metabolism. This study examined the effects of 10 g of EAAs in two different groups: a 3.5g Leucine group or a 1.87g Leucine group [3]. Subjects performed one hour of slow steady state (endurance) exercise while consuming their BCAA/EAA mixture over the course of two weeks.
The interesting finding of this study was that muscle protein synthesis (MPS) was as much as 33% greater in the 3.5g Leucine group than the 1.87 g leucine group. This shows that leucine amount is key to activating MPS. They also found that whole body protein breakdown was lower. So you may be thinking to yourself, well that’s pretty common sense, leucine activates MPS so what makes this study unique?

This study was done by the US Military, so there is no inherent bias from the funding source.
This study shows the importance of Leucine and shows that the ratio of BCAA’s is not important. For years, people have touted the so-called “2:1:1” ratio as best (oddly enough, a majority of research is actually not using the so-called “2:1:1” ratio that is being touted as best [4]), but this study shows that ratio does not matter. The high Leucine group in this study used essentially a 4:1:1 ratio (refer to figure 1). This study shows as long as you get enough EAA’s, Leucine content is what’s most important, not the ratio. This study also highlights the importance of EAA’s during endurance exercise; an area of research that BCAA’s alone have been unable to do so far.

The lack of Carbohydrates. A large number of studies investigating the effects of BCAA’s confound the research findings by including Carbohydrates with their BCAA or EAA mixture. Not all athletes consume carbohydrates during exercise, making the findings of those studies difficult to extrapolate into real-world results. We currently live in an industry that is petrified of carbohydrates even though they have lots of ergogenic potential.

Figure 1 Why are these findings important? Unlike resistance exercise, endurance exercise is truly catabolic. Endurance exercise results in lower rates of MPS and plasma Leucine concentration [3]. This means when you are performing endurance exercise, not only are you deficient in plasma Leucine content in your bloodstream, but you are also deficient in stimulating muscle protein synthesis as well. This one-two combination can have a major catabolic effect on your body. The data from the US military study indicates that increasing Leucine availability during endurance exercise promotes skeletal muscle protein anabolism and spares endogenous protein. This prevents the catabolic effects of endurance exercise.
What about protein?

According to the U.S. Dairy Council, Whey Protein offers the highest concentration of BCAAs of any dietary source of Protein at about 26 g of BCAAs per 100g of Protein. Whey protein itself has a multitude of benefits and has the optimal amount of BCAA’s/EAA’s one would use when using an intra-workout product. This means if you are simply low on money, Whey Protein is your best chance to make sure you are getting an increase in muscle protein synthesis rate (refer to figure 2). It is important to note that BCAA & EAA products provide “free form” amino acids, so they do not count towards your daily protein intake, and that they do contain calories unlike what you see on most supplement facts for most Amino products.

Take Home Message

So what’s the take-home message? Well, if you are going to take additional amino acids in your diet through a supplement, there are only two things you really should look for:

Leucine content. Know how much you are consuming. Take at least 2.5 g or more.
Take Leucine with additional EAAs. Also make sure you take the full 10 grams, which does include the Leucine content.

Do not just take BCAAs, because if you are going to be supplementing, you should supplement what is needed…Essential Amino acids with a high Leucine content. Anyone selling an EAA product with a proprietary blend under 10 grams is not doing you any favors.