Some studies indicate this "window of opportunity" can even be extended to 2 hours after the training session.
However, Alan Aragon found that the pre- and post workout meal ideally shouldn't be separated with more than 4 hours. Lean body mass x 0.4-0.5 grams of protein in both meals for maximum anabolic effect.
I don't take a post workout shake either.
Im guessing kg, 1g/lb in a 4 hour window is a lot.