BCAA's have been around for a long time. Many people use them in and around their workouts in order to help boost muscle protein synthesis, prevent muscle soreness, and honestly as a great tasting, low-calorie drink. But do they actually work?

Low Down On BCAA's

BCAA's (Branch Chain Amino Acids) are 3 of the 9 EAA's (Essential Amino Acids). Essential Amino acids cannot be produced by your body and must be taken in through diet. The 3 BCAA's are Leucine, Isoleucine and Valine. The primary BCAA is Leucine, which is also known as the anabolic trigger. Leucine has been shown to signal muscle protein synthesis which helps you build muscle. It has generally been thought that Leucine is most effective in the presence of the other two BCAA's, and that the 3 Amino Acids together were enough to stimulate muscle protein synthesis.

Amino Acids & Muscle Growth

In order to understand the effects of Amino Acids, we need to look at muscle growth and specifically muscle protein synthesis (MPS). Our bodies are in a constant state of both muscle protein synthesis and muscle protein breakdown. At a basic level, when muscle protein synthesis is greater than muscle protein breakdown we achieve muscle growth. Cool! But how does this happen?

Muscle protein synthesis is achieved when all 9 Essential Amino Acids are present in sufficient amounts. As we said before, EAA's cannot be produced by your body and must be taken in from your diet. While your body does store EAA's resulting from muscle protein breakdown, it is in small amounts and is likely to be quickly depleted. Logically, if you are constantly in a state of muscle protein breakdown and are only recycling EAA's, your rate of synthesis will never exceed your rate of breakdown.

So what does this mean for BCAA's? Well, as we discussed, all 9 EAA's are needed to achieve a state of muscle protein synthesis. BCAA's contain only 3 of the 9. Since BCAA supplements do contain Leucine, a small spike in muscle protein synthesis can be achieved by utilizing your body's EAA stores. However, these stores will quickly become depleted, thereby stopping muscle protein synthesis.

So What Should I Be Taking?

If you are looking for a good supplement to take in and around your workouts, Essential Amino Acids are the way to go. A good EAA supplement will have a high amount of Leucine to signal MPS, and sufficient amounts of the other 9 EAA's to sustain muscle protein synthesis. Studies have shown that muscle protein synthesis is maximally stimulated by 3.5g of Leucine in a 10g total EAA blend. This stimulates muscle protein synthesis to a rate equivalent to 25g Whey Protein. An example of a good EAA supplement is NutraBio Intra Blast. Intra Blast is the only EAA supplement I'm aware of that contains both 3.5g Leucine and 10g total EAA's.

Protein should also be considered when looking at EAA intake. A high-quality protein source contains all 9 Essential Amino Acids and high amounts of Leucine. Dairy protein, especially whey, is ideal in this aspect and contains higher amounts of Leucine than other forms of protein. Egg and meat protein are also great protein sources.

If you are trying to build muscle, the general guideline is to take in 1g of protein per pound of bodyweight per day. This is also a great guideline for dieters to maintain muscle mass in a caloric deficit. EAA supplements can be supplemented around your workout and between meals in order to stimulate muscle protein synthesis. For dieters, 10g EAA contains roughly half as many calories as the equivalent amount of whey protein isolate (yes amino acids have calories).

In summary, BCAA supplementation alone is next to useless assuming you have adequate protein intake throughout the day. If you are looking for a supplement to take other than protein, Essential Amino Acid supplements containing 3.5g Leucine and 10g total EAA's are the way to go. In regards to supplements, watch out for EAA supplements with proprietary blends (one dosage listed for multiple ingredients) that include non-essential amino acids. In these cases, the company is likely including these in high doses in order to cheapen the product. Ideally, you will find a supplement that lists each ingredient along with its dosage.