The Leucine Trigger By Stuart Phillips, Ph.D. and Co-Author of the International Olympic Committee’s consensus statement on dietary supplements

Kickstart muscle recovery with the amino acid that counts

Imagine you’re building a wall that is repeating pattern containing 20 bricks. We need delivery of 9 of those bricks, but we can make the other 11 ourselves. But one brick gets the whole process going, and without it, nothing happens. Now imagine that the wall is the proteins that make up your muscles, and that wall gets damaged every time we exercise. But in recovery, we rebuild and repair that wall and make it better than it was before (1). Enhanced Recovery™ contains an unprecedented combination of ingredients and one critical ingredient, the amino acid leucine.

The bricks that are used to build our muscles, connective tissues, and even our bones are called amino acids, and there are 9 of them that we need to have. We call these nine amino acids “essential” or “indispensable amino acids,” meaning that we need to have them in our diets from the proteins we consume (2). The protein in our diet provides these nine essential amino acids so we can repair damaged proteins and build new ones. Every time they train, athletes create a situation where there is increased damage to proteins and especially in their muscles (1). The good news is that the damage gets repaired (3), and that’s where Enhanced Recovery™ comes in because it contains a blend of proteins and is enriched with leucine. This protein-leucine blend is a potent combination that provides a dose of leucine to switch on a process known as Muscle Protein Synthesis or MPS. When MPS is turned on, it’s the natural repair process that our muscles use to replace damaged proteins with new ones (4). It’s like a constant repair mechanism for your muscle, but the amino acid that drives MPS is leucine (2). Leucine triggers a series of complex molecular events that are akin to firing up the repair crew and getting all of the other amino acids into the proteins to make new proteins that form your muscles (4).  

Chain of amino acids in a protein. The amino acids shown are: Phe – phenylalanine, Leu – leucine, Ser – serine, and Cys – Cysteine (

Research has shown that just feeding people leucine alone can stimulate MPS (5), but you need all the other amino acids to make new proteins (6). In fact, even very low doses of protein can be made to be more potent by adding leucine (7), and low-quality proteins can also be made to be more effective in stimulating MPS when leucine is added (8).

The rise in leucine inside the muscle after exercise acts as a trigger to stimulate MPS. The higher the leucine the greater the stimulation of MPS. Adapted from (2), with permission.

When it comes to repairing damaged muscle in recovery from exercise, protein is what your body needs to turn on MPS and leucine is the primary amino acid that triggers the whole process. That’s why Enhanced Recovery™ has a blend of whey, collagen, and sunflower seed protein with leucine to get recovery going right away. But, Enhanced Recovery™ is more than just protein; it contains omega-3 lipids that can enhance the effectiveness of protein (9). Enhanced Recovery™ is simply an unbeatable combination of ingredients to support recovery!

Molecular structure of leucine (


1.            Churchward-Venne TA, Burd NA, Phillips SM. Nutritional regulation of muscle protein synthesis with resistance exercise: strategies to enhance anabolism. Nutrition & Metabolism 2012;9. doi: 10.1186/1743-7075-9-40.

2.            Phillips SM. The impact of protein quality on the promotion of resistance exercise-induced changes in muscle mass. Nutr Metab (Lond) 2016;13:64. doi: 10.1186/s12986-016-0124-8.

3.            Damas F, Phillips S, Vechin FC, Ugrinowitsch C. A Review of Resistance Training-Induced Changes in Skeletal Muscle Protein Synthesis and Their Contribution to Hypertrophy. Sports Medicine 2015;45(6):801-7. doi: 10.1007/s40279-015-0320-0.

4.            Stokes T, Hector AJ, Morton RW, McGlory C, Phillips SM. Recent Perspectives Regarding the Role of Dietary Protein for the Promotion of Muscle Hypertrophy with Resistance Exercise Training. Nutrients 2018;10(2). doi: 10.3390/nu10020180.

5.            Wilkinson DJ, Hossain T, Hill DS, Phillips BE, Crossland H, Williams J, Loughna P, Churchward-Venne TA, Breen L, Phillips SM, et al. Effects of leucine and its metabolite beta-hydroxy-beta-methylbutyrate on human skeletal muscle protein metabolism. J Physiol 2013;591(Pt 11):2911-23.

6.            Volpi E, Kobayashi H, Sheffield-Moore M, Mittendorfer B, Wolfe RR. Essential amino acids are primarily responsible for the amino acid stimulation of muscle protein anabolism in healthy elderly adults. AmJClinNutr 2003;78(2):250-8.

7.            Churchward-Venne TA, Breen L, Di Donato DM, Hector AJ, Mitchell CJ, Moore DR, Stellingwerff T, Breuille D, Offord EA, Baker SK, et al. Leucine supplementation of a low-protein mixed macronutrient beverage enhances myofibrillar protein synthesis in young men: a double-blind, randomized trial. American Journal of Clinical Nutrition 2014;99(2):276-86. doi: 10.3945/ajcn.113.068775.

8.            Gorissen SH, Horstman AM, Franssen R, Crombag JJ, Langer H, Bierau J, Respondek F, van Loon LJ. Ingestion of Wheat Protein Increases In Vivo Muscle Protein Synthesis Rates in Healthy Older Men in a Randomized Trial. J Nutr 2016;146(9):1651-9. doi: 10.3945/jn.116.231340.

9.            Phillips SM. Nutritional supplements in support of resistance exercise to counter age-related sarcopenia. AdvNutr 2015;6(4):452-60.