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In this blog, I'll be sharing posts on BCAAs including from knowledge and experience worldwide.

From http://jn.nutrition.org/content/134/6/1583S.full.pdf

Furthermore, BCAA supplementation before and after exercise has beneficial effects for decreasing exercise-induced muscle damage and promoting muscle-protein synthesis; this suggests the possibility that BCAAs are a useful supplement in relation to exercise and sports.

The branched-chain amino acids (BCAAs) 3 leucine, iso-leucine, and valine are among the nine essential amino acids for humans and account for ;35% of the essential amino acids in muscle proteins and ;40% of the preformed amino acids required by mammals (1). Because animal and human cells have a tightly controlled enzymatic system for BCAA degradation, BCAAs that are ingested in excess are quickly disposed of (2). Although BCAAs are absolutely required for protein synthesis, some intermediates formed in their catabo-lism [e.g., branched-chain a-keto acids (BCKA)] can be toxic at high concentrations (1). Therefore, the disposal of excess BCAAs is critically important for maintaining normal body conditions.

It is known that BCAAs can be oxidized in skeletal muscle, whereas other essential amino acids are catabolized [ca·tab·o·lism (k -t b -l z m). n. The metabolic breakdown of complex molecules into simpler ones, often resulting in a release of energy] mainly in liver (3). Exercise greatly increases energy expenditure and promotes oxidation of BCAAs (3). It is believed that BCAAs contribute to energy metabolism during exercise as energy sources and substrates to expand the pool of citric acid–cycle intermediates (anaplerosis) and for gluconeogenesis. In contrast, leucine is special among the BCAAs, because it promotes muscle-protein synthesis in vivo when orally administered to animals (4).

As a consequence of these findings, BCAAs are receiving considerable attention as potentially helpful dietary supplements for individuals who enjoy exercise and participate in sports.

Toxicity of BCAA. Acute and subacute toxicity studies of BCAAs using mice and rats (30) and a chronic toxicity study using rats (31) were reported. The BCAA composition used in these studies was a 2.1:1:1.2 leucine : isoleucine : valine ratio. No animals died from the single dose of 10 g of BCAA/kg body wt in the acute toxicity study, and the half-maximal lethal dose was estimated as .10 g/kg body wt. No toxic effects of BCAAs were observed at a dose of 2.5 g/kg/day for 3 mo or 1.25 g/kg/day for 1 y. There are no reports concerning BCAA toxicity in relation to exercise and sports.

It is clear that exercise promotes degradation of BCAAs. Promotion of fatty acid oxidation appears to be associated with greater rates of BCAA oxidation, which suggests that fatty acids may be regulators of BCAA oxidation. Furthermore, muscle-protein synthesis is enhanced after exercise. From these findings, it may be concluded that the BCAA requirement is increased by exercise.

BCAA supplementation before and after exercise has beneficial effects for decreasing exercise-induced muscle damage and promoting muscle-protein synthesis; this suggests that BCAAs may be a useful supplement in relation to exercise and sports.

Although in many human exercise studies, a dose of .5 g of BCAA was used as a supplement, the minimum dose to produce the beneficial effects of BCAA supplementation remains to be established.

Furthermore, the most effective ratio of the three BCAAs is unclear. Toxicity studies of BCAAs using animals showed that BCAAs are quite safe amino acids when the three BCAAs are provided in a ratio similar to that of animal protein (e.g., a 2:1:1 leucine : isoleucine : valine ratio). Although leucine is the most potent amino acid among the BCAAs for stimulating protein synthesis, supplementation of leucine alone may cause BCAA imbalance via the activating effect of its keto acid on the BCKDH complex.

Best!

Shakti