BCAA's on off days

Posted by: @str8flexed

you aren't thinking about this in proper terms, and it's tough unless you've had classes in cell biology or biochemistry (not trying to sound condescending, it's just the truth).  Leucine stimulates protein synthesis, you don't need other amino acids in the mixture because unless you are starving, it's not as if your body is devoid of these amino acids.  Now eventually if you don't take any other EAAs in protein synthesis will be limited.  The point is the body uses leucine as a sensor for total protein intake.  Instead of having a mechanism to moniter the concentrations of every amino acid in the body (which would be energetically expensive) evolution selected for leucine as the marker to tell the body "hey there's enough leucine, so there must be enough total protein" and allows stimulation of protein synthesis.

-Layne

No offense taken, I can admit I'm pretty limited about this stuff. Everything you said makes sense, I guess I was taking "Leucine can stimulate protein synthesis" to literally. Thanks.

Posted by: @str8flexed

How much leucine do you think someone would want to use on off days, assuming the goal is to stave off catabolism?

depends on total protein intake, but i'd say 10g of leucine is plenty (20g of BCAA)

Cool, thanks.

Also, I recall a thread about BCAA's a while back where Zeppelin had a concern about large amounts of leucine competing for absorption with other aminos (isoleucine and valine I think, maybe others). I can see how it wouldn't be a problem during exercise, as you're looking for a specific effect... any issues with supplementing with leucine at other times though?

Posted by: @str8flexed

don't quite see what you are getting at

BCAA's are mostly taken pre-during-post workout. Why is that timing so important?

Posted by: @Drachus

BCAA's are mostly taken pre-during-post workout. Why is that timing so important?

Protein synthesis rates are higher during and immediately after working out; the same applies to insulin sensitivity in the muscles that were used. Supplying extra leucine in this time frame (along with carbohydrates and protein) elevates protein synthesis even more, and I believe leucine also increases the insulin response and prolongs the sensitivity (someone correct me if I'm wrong).

As Layne said, leucine also increases protein synthesis in the absence of exercise, but in the immediate post-workout timeframe, it is synergistic with your body's own hormonal milieu. I would think taking it outside of this window, as before bed or upon waking, would also be beneficial since, as you said, the myofibrils are being repaired for many hours after said window, but it will be most beneficial in the immediate period.

Thanks Thats what I was wondering. I started researching the physiology of protein synthesis to be sure I was wording my question correctly LOL

So I take it ammounts should remain consistent on a daily basis, 10g leucine 5g isoleucine 5g valine every day.