It seems that the bulk of the rationale for supplementing free form BCAA's relates to and it's role in stimulating muscle protein synthesis. Because of this, retailers have begun to sell BCAAs in a 4:1:1 ratio instead of the classic 2:1:1. Why not just get pure Leucine? Is there any reason to supplement Isoleucine and Valine? Do we not get enough of these to meet metabolic demands from a high protein diet consisting of lots of egg, meat, whey, casein, etc.?
I have noticed that bulk Leucine is cheaper than bulk 4:1:1 BCAAs so if it is both more effective (in theory) and cheaper ($12.34 vs. $16.90 per lb from TP). Why not just supplement with the pure stuff?