I really think it's all about trial and error, not only warm-up, but everything involved in weightlifting as stated above. I used to be stuck on the Max-OT program, but I didn't really see any size gains at all. Now I do the 5x5, and getting great results, but I tweaked my warmup a little myself, I do:1st set 12 reps, 2nd set 10 reps, 3rd set 6 reps, and last warmup set3 reps. I used to do the one, but zi don't think it works for me, I need my last set to be a rep type set, instead of only one. But that's just me, I'm far from an expert.