Gentlemen,
First off, obviously your not doing a powerlifting routine as if you were, there is no such thing as back and legs on the same day (unless you consider deadlift and squat) dead's may be considered back also. But in generla froma weightlifting or bodybuilding workout standpoint you are absolutely kidding yourself. I question your intensity and just how your working. After a squat session I am totally spent no f*cking way can I do a big muscle group like back. And if you do back first, then your kidding yourself again, because no way will you give your all on your squat work.
Cubanito, I didn't say 2 main muscle groups I said 2 large muscles groups, I do not consider shoulders or even chest to be as large as back or legs. split up back and legs thats all I'm saying.
I'm not flaming anyone, I'm just saying I truly question your intensity. Powerlifting aside , you would not make it through a squat workout with me and I do not over-train either. IN fact after a squat workout with me the only back work you'll do is your back laying in a pool of your own vomit.
Think gentlemen, think talk to any bodybuilder, powerlifter or even fitness trainer and tell them back and legs in the same workout they will probably laugh in your face.
Love,
Mike