Pro Test 180Getting the most out of your protein As aforementioned, protein source matters since MPS is differentially stimulated in proportion to the EAA content (and specifically L-leucine) of each meal. A conservative estimate, based on extrapolations, is that 30 grams of a leucine-rich protein source (such as most animal proteins and whey protein) is plenty to sufficiently elevate MPS for a good 3-4 hours. (5) Again, this is just a starting point (read: baseline) for active individuals but is by no means a strict rule. http://getmenshealth.com/pro-test-180/