Leucine is one of several Branched chain amino acids (BCAA’s). It is essential for protein synthesis which is stimulated after exhaustive exercise (24) as well as the critical metabolic process in muscle (25, 26). The metabolic roles of Leucine include energy production and the modulator of muscle protein synthesis via the insulin signalling pathway. There is a reason to suggest that it helps maintenance of muscle mass during weight loss (27). Leucine has also been shown to help in the direct maintenance of glucose homeostasis by improving the redistribution of glucose via the glucose – alanine cycle (28).


24 – Tipton, K. D., Ferrando, A. A., Phillips, S. M., Doyle Jr, D., & Wolfe, R. R. (1999). Postexercise net protein synthesis in human muscle from orally administered amino acids. American Journal of Physiology-Endocrinology And Metabolism, 276(4), E628-E634.

25 – Hutson, S. M., & Harris, R. A. (2001). Introduction. Symposium: Leucine as a nutritional signal. The Journal of nutrition, 131(3), 839S-840S.

26 – Layman, D. K. (2002). Role of leucine in protein metabolism during exercise and recovery. Canadian journal of applied physiology, 27(6), 646-662.

27 – Layman, D. K. (2003). The role of leucine in weight loss diets and glucose homeostasis. The Journal of nutrition, 133(1), 261S-267S.

28 – Herman, M. A., & Kahn, B. B. (2006). Glucose transport and sensing in the maintenance of glucose homeostasis and metabolic harmony. The Journal of clinical investigation, 116(7), 1767-1775.