question about leucine supplement

[gerasimos]

hello.i am a olympic style weightlifter and i want to start a cycle with creatine and leucine.when is the besr time to take these supplements and is better to take leucine from bcaa?

 

[Michael Scally MD]

hello.i am a olympic style weightlifter and i want to start a cycle with creatine and leucine.when is the besr time to take these supplements and is better to take leucine from bcaa?

I have never heard of a leucine cycle. It really makes no sense, particularly since leucine is an essential amino acid. [ame="http://en.wikipedia.org/wiki/Leucine"]Leucine - Wikipedia, the free encyclopedia@@AMEPARAM@@/wiki/File:L-leucine-skeletal.png" class="image"><img alt="" src="http://upload.wikimedia.org/wikipedia/commons/thumb/2/29/L-leucine-skeletal.png/120px-L-leucine-skeletal.png"@@AMEPARAM@@commons/thumb/2/29/L-leucine-skeletal.png/120px-L-leucine-skeletal.png[/ame] Overall, I have never found the logic of the BCAA supplement. If you are not getting enough BCAA in your diet, you are not getting anywhere enough protein! Here are some articles on BCAA.



Rennie MJ, Bohe J, Smith K, Wackerhage H, Greenhaff P. Branched-Chain Amino Acids as Fuels and Anabolic Signals in Human Muscle. J Nutr 2006;136(1):264S-8.

During exercise, there is an increase in amino acid (AA) oxidation accompanied by a depression in whole-body protein synthesis and an increase in protein breakdown. Leucine oxidation increases in proportion to energy expenditure, but the total contribution of BCAA to fuel provision during exercise is minor and insufficient to increase dietary protein requirements. When investigating the effects of AA on the control of muscle protein synthesis (MPS), we showed that increased availability of mixed AAs caused a rise in human MPS to about the same extent as complete meals. Leucine alone (and to some extent other essential, but not nonessential, AAs) can stimulate MPS for a short period, suggesting that leucine acts as a signal as well as a substrate. MPS stimulation by infused AAs shows tachyphylaxis, returning to basal rates after 2 h, possibly explaining why chronically elevated leucine delivery does not elevate MPS clinically. Increased availability of essential amino acids (EAAs) results in dose-related responses of MPS, but, in elderly subjects, there is blunted sensitivity and responsiveness associated with decreased total RNA and mRNA for signaling proteins and signaling activity. Increases of MPS due to EAAs are associated with elevation of signaling activity in the mammalian target of rapamycin (mTOR)/p70 ribosomal subunit S6 kinase eukaryotic initiation factor 4 binding protein 1 pathway, without requiring rises of plasma insulin availability above 10 {micro}U/mL. However, at insulin of <5 {micro}U/mL, AAs appear to stimulate MPS without increasing mTOR signaling. Further increasing availability of insulin to postprandial values increases signaling activity, but has no further effect on MPS.


Shimomura Y, Yamamoto Y, Bajotto G, et al. Nutraceutical Effects of Branched-Chain Amino Acids on Skeletal Muscle. J Nutr 2006;136(2):529S-32.

BCAA catabolism in skeletal muscle is regulated by the branched-chain {alpha}-keto acid dehydrogenase (BCKDH) complex, located at the second step in the BCAA catabolic pathway. The activity of the BCKDH complex is regulated by a phosphorylation/dephosphorylation cycle. Almost all of BCKDH complex in skeletal muscle under normal and resting conditions is in an inactive/phosphorylated state, which may contribute to muscle protein synthesis and muscle growth. Exercise activates the muscle BCKDH complex, resulting in enhanced BCAA catabolism. Therefore, exercise may increase the BCAA requirement. It has been reported that BCAA supplementation before exercise attenuates the breakdown of muscle proteins during exercise in humans and that leucine strongly promotes protein synthesis in skeletal muscle in humans and rats, suggesting that a BCAA supplement may attenuate muscle damage induced by exercise and promote recovery from the damage. We have examined the effects of BCAA supplementation on delayed-onset muscle soreness (DOMS) and muscle fatigue induced by squat exercise in humans. The results obtained showed that BCAA supplementation prior to squat exercise decreased DOMS and muscle fatigue occurring for a few days after exercise. These findings suggest that BCAAs may be useful for muscle recovery following exercise.