Of the three BCAA's, Leucine plays a special role in skeletal muscle metabolism, in particular by exerting an anti-catabolic and anabolic effect on protein metabolism(3, 5-7, 9).  Leucine metabolites that have been sold as sports (HMB) or animal feed supplements (keto-isocaproate) also exert anabolic effects in humans and growing animals(2, 11).   In fact, Leucine incorporation into skeletal muscle has long been used as a marker of muscle protein synthesis(10) and oxidation(1).  Because leucine so powerfully stimulates muscle protein synthesis, some researchers have suggested Leucine supplementation to combat age-associated loss of skeletal muscle mass (sarcopenia)(3).

The "branched chain" amino acids (BCAA's), Leucine, isoleucine and valine are so called because the side chains of these amino acids (the part of the molecule that differentiates the amino acids) are made up of non-linear (branching) carbon chains.  The BCAA's are essential amino acids, meaning that they must be consumed in the diet (rather than manufactured in the body) and constitute a more than one third of the amino acid composition of skeletal muscle(8).  During high intensity exercise, the BCAA's are oxidized for use as fuel and to maintain oxidative metabolite concentration(4).  Supplementing with BCAA's reduces exercise-induced muscle proteolysis (breakdown)(14) and also stimulates muscle protein synthesis(13).  Daily BCAA supplementation may also reduce muscle damage, promote strength recovery and even enhance blood oxygen carrying capacity(12).

Directions

As a dietary supplement, take 5-10g before extensive exercise. Take an additional 5-10g following workout.

Ingredients

L-Leucine.

Packaging

Packaged in heat-sealed foil pouches.

General Warnings

If you are currently pregnant or nursing, consult a physician prior to use. Keep out of the reach of children.

Allergen Warnings

This product is free from all forms of shell fish, tree nuts, yeast, gluten, salt, preservatives, artificial ingredients, lactose, and soy. This product is manufactured in a facility that handles soy, gluten, and milk products.

Volumetric Measures: 

Use the table below to approximate the gram equivalent weight for a given level measuring spoon (US Standard). Please note that accurate dosing should only be done with a recommended calibrated scale.

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References

1.         Boirie Y, Dangin M, Gachon P, Vasson MP, Maubois JL, and Beaufrere B. Slow and fast dietary proteins differently modulate postprandial protein accretion. Proc Natl Acad Sci U S A 94: 14930-14935, 1997.

2.         Flakoll PJ, VandeHaar MJ, Kuhlman G, and Nissen S. Influence of alpha-ketoisocaproate on lamb growth, feed conversion, and carcass composition. J Anim Sci 69: 1461-1467, 1991.

3.         Fujita S and Volpi E. Amino acids and muscle loss with aging. J Nutr 136: 277S-280S, 2006.

4.         Gibala MJ. Regulation of skeletal muscle amino acid metabolism during exercise. Int J Sport Nutr Exerc Metab 11: 87-108, 2001.

5.         Goldberg AL. Protein synthesis during work-induced growth of skeletal muscle. J Cell Biol 36: 653-658, 1968.

6.         Goldberg AL, Etlinger JD, Goldspink DF, and Jablecki C. Mechanism of work-induced hypertrophy of skeletal muscle. Med SciSports 7: 185-198, 1975.

7.         Goldberg AL and Goodman HM. Amino acid transport during work-induced growth of skeletal muscle. Am J Physiol 216: 1111-1115, 1969.

8.         Harper AE, Miller RH, and Block KP. Branched-chain amino acid metabolism. Annu Rev Nutr 4: 409-454, 1984.

9.         Kimball SR and Jefferson LS. Signaling pathways and molecular mechanisms through which branched-chain amino acids mediate translational control of protein synthesis. J Nutr 136: 227S-231S, 2006.

10.       Nair KS, Halliday D, and Griggs RC. Leucine incorporation into mixed skeletal muscle protein in humans. Am J Physiol 254: E208-213, 1988.

11.       Nissen S, Sharp R, Ray M, Rathmacher JA, Rice D, Fuller JC, Jr., Connelly AS, and Abumrad N. Effect of leucine metabolite beta-hydroxy-beta-methylbutyrate on muscle metabolism during resistance-exercise training. J Appl Physiol 81: 2095-2104, 1996.

12.       Ohtani M, Sugita M, and Maruyama K. Amino acid mixture improves training efficiency in athletes. J Nutr 136: 538S-543S, 2006.

13.       Shimomura Y, Murakami T, Nakai N, Nagasaki M, and Harris RA. Exercise promotes BCAA catabolism: effects of BCAA supplementation on skeletal muscle during exercise. J Nutr 134: 1583S-1587S, 2004.

14.       Tang FC. Influence of branched-chain amino acid supplementation on urinary protein metabolite concentrations after swimming. J Am Coll Nutr 25: 188-194, 2006.