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Position Stand: BCAA Supplementation

In this review, Luke, Owner of Shift to Strength, expresses the company’s current position on BCAA, or Branch Chain Amino Acid supplementation. The supplement will be critically reviewed to help answer the following questions:

  1. What are BCAAs, how are they different from other amino acids, and what is their role in skeletal muscle repair?

  2. Are they worth supplementing?

  3. Who should be taking them?


It is the Position of Shift to Strength that Branch Chain Amino Acid (BCAA) supplementation, in the vast majority of cases, is not necessary to supplement for optimal results. Instead, the total amount of high-quality protein sources consumed should be emphasized. This is because consuming a high protein diet of ~1.6g/kg/day offsets the need to consume BCAAs as essential amino acid profiles become proficient at this point to maximize results (1,2,3).

What are BCAAs, how are they different from other amino acids and what is their role in skeletal muscle repair?

BCAAs are three amino acids that, along with the other six Essential Amino Acids, or EAAs, are not created by the body and, therefore, must be consumed by dietary or supplemental means.

A close-up of quinoa seeds.

This is in contrast to non-essential amino acids, which the body can create internally. Both essential and non-essential amino acids make up the protein macronutrient in varying degrees, depending on the specific source. For example, a “complete” protein includes all essential amino acids, including BCAAs:

  • All animal proteins: meat, poultry, fish, eggs and dairy

  • Quinoa

  • Buckwheat

  • Hempseed

  • Blue-green algae

  • Soybeans

A farmer's market booth of vegetables.

In contrast, an “incomplete” source of protein does not include all essential amino acids and, therefore, it becomes more important to combine different sources to meet your body’s protein needs:

  • Nuts

  • Seeds

  • Whole grains

  • Vegetables

  • Legumes

Why is this important in the context of BCAA supplementation? Recall that branch chain amino acids are three specific essential amino acids found in varying degrees in the above foods. The question is if they are already found in whole foods, why supplement them?

Branch chain amino acids have been studied since the 1980’s when it was first observed that three specific amino acids, leucine, isoleucine and valine, were found to break down in skeletal muscle as opposed to the liver with the other essential amino acids (2). This led researchers to hypothesize that the branch chain amino acids play a predominant role in muscle growth and repair.

A molecular breakdown of Leucine.

Since then, multiple lines of evidence support that when BCAAs are supplemented in a diet, they outperform controls (2,3). More specifically, it appears that leucine is the most important amino acid for muscle growth and repair. Several studies have shown that adding leucine to a protein led to greater muscle growth and repair than without (1,2,3,4,5,6).

Are they worth supplementing?

At first glance, it may seem like supplementing BCAAs is well worth it. The current literature supports the notion that branch-chain amino acids play a significant role in muscle growth, so why not supplement them to maximize muscle growth and recovery?

It’s the company’s position that although it is true that BCAAs are the prime amino acids responsible for muscle growth and repair, when protein content is consistently held between groups, the benefits of BCAAs disappear; therefore, BCAA supplementation is not required when a high-protein diet is consumed (1,5,6). The company makes this position stand based on the following evidence.

Firstly, most studies looking at the effectiveness of BCAAs compare the supplement to a placebo. In these studies, the investigations aimed to see the isolated effects the supplement had on the body. A better real-world analysis of the supplement’s effectiveness would be to compare BCAAs directly to protein powder, a similar protein source or control for protein in the diet. Churchward-Venne and colleges did just that.