This study shows how mTOR and P70s6K are highly elevated post workout with a protein drink. We know that the effects of BCAA and resistence exercise are additive, however if you note the 48hour mark, there is virtually no difference for P70s6K, although mTOR is still up a bit.
What these results dont show that I think is important is area under curve. Although the cross-sectional area of the protein group was higher when measured.
Interesting to see how protein stopped the myostatin decrease, but it also totally blunted the testosterone response. And we have seen how Testoserone can negatively regulate Myostatin, perhaps this is where the connection is.