That prerequisite thing is really funny. I have the original copy of the fitness guide. The original version is actually like, ok guys, you have to be in really good shape to get through this and do everything properly, this is intended for people that have already gone through our Power 90 program, consider trying one of our other programs first before P90X because it is really intense and you need some base strength.
Then it started selling really well and they rewrote the manual to make it seem more accessible to everyone, to make mo money basically.
I started doing the Power 90 one this week, I'm on day 5. I wanted to do P90X but I don't have a chinup bar or resistance bands, so I downloaded it anyway and I figured I'd just skip the chinup parts, but then I realized that in a couple of the routines you are pretty much just doing chinups for an hour and a half straight. The Power 90 program requires only a set of dumbbells, which I already have, so I'm just gona try it for a while till I can afford a chin up bar and the other stuff you need for P90X.
Its more of a cardio thing really though, the way the excersizes are set up forces you to lift about half of what you would normally lift. It won't get you "ripped". I just got tired of my normal lifting/jogging routine so I thought it might be fun for a little while.