Stick With Protein – Carbs and Alanine Won’t Help You

Researchers compared an essential amino acid supplement with the same supplement combined with either carbohydrate or alanine. Turns out all you really need for muscle synthesis is protein.

Net protein balance is an important aspect of an athlete’s training. Maintaining or building lean mass is good for most athletes, and on occasion sometimes an athlete even needs to lose a little muscle mass. Protein balance is one piece to that puzzle, but how does it work exactly and how can we manipulate it?

As the term implies, there needs to be a change in the balance in order for there to be a change in your musculature. The bigger question here is what is being balanced? The simplest viewpoint is generally the best, so let’s keep it simple. Protein synthesis, which is essentially the development of new muscle, is balanced against muscle protein breakdown, which would be the loss of existing muscle. Both of these processes occur daily in normal people, but they are typically balanced out so there is no net change in total muscle proteins.

Many things we do alter our protein balance, but a recent study in The Journal of Nutrition compared an essential amino acid supplement with the same supplement combined with either carbohydrate or alanine. Why would they compare these things? Well, essential amino acids are those needed in the diet in order for a person to live. They are also the building blocks of protein, and so they support the growth of new muscle. Carbohydrates have also been shown to decrease muscle breakdown and stimulate insulin, which both promotes synthesis of new muscle and inhibits breakdown of existing muscle. Researchers chose alanine for its role in creating new glucose in the liver, taking the stress off of muscle degradation as a means of obtaining energy.

The results were not what you might be thinking. There was very little difference between each group. All three methods of supplementation increased net protein balance in just about the same degree. Although the group that added carbohydrates to their essential amino acids showed a small increase in balance, there was no major difference. The alanine group showed a delay in the response, which makes sense. For the purposes of this study alanine was essentially a time-released carbohydrate.

Because of studies like this, we now know two important things regarding our traditional knowledge of nutrition and muscle building. The first is that carbohydrates are not as critical to total muscle balance as we used to believe. Well, ingesting it isn’t anyway. Each group had an increase in insulin after supplementing, which means that there was glucose present in the blood of those only taking the amino acids. That’s because some of those amino acids were being turned into sugar, which probably completely accounts for the small difference in net protein balance. The second is that good old fashioned protein is about as anabolic as legal supplements get. And we don’t even have to go to the vitamin store to get it. They have it right at the grocery store.

The industry created obsession with consuming a golden ratio of carbs with protein after a workout has got to go. When it comes to muscle building it’s just not as important as we’ve been led to believe. Keep your carbs limited to maintaining your glycogen stores, and let protein take care of the rest.


1. Erin Glynn,, “Addition of Carbohydrate or Alanine to an Essential Amino Acid Mixture Does Not Enhance Human Skeletal Muscle Protein Anabolism,” The Journal of Nutrition, 143:3 (2012)

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