Amino acids is a pain in the ass because it needs to be taken on an empty stomach to be effective. Luke Wood posted that he takes it 45 minutes prior to working out, at that time his stomach needs to be pretty much empty, which means it would be maybe 1-1,5 hour since he had some food... thats 2+ hours witout eating anything before hitting the gym...
So one gotta think about whats more beneficial, the extra energy you get from eating before hitting the gym, or not eating and sap your strength because you wanna use amino acids.