From what I've read, you should be in "P90X ready" shape to get the most out of the program. I thought about it but then read Beachbody info and found out that most simple test is "Can you make 3 good form pull up (1 for female)". I couldn't do more then 1 or 2. Information says that you can certainly go through the program and there are alternative moves just that requirements help to get best results.
So, I decided to start with Power half-hour. Did 5 weeks of "Upper body" program. Now it's Power 90, about 1/4 in at this point. Power 90 does get a bit repetitive, there are 2 work outs for Phase 1 and 2 others for later. I like what I see in the mirror, though. And, most importantly, what I feel. I've lost a bit of weight. Like 12Lb (it was my "quit smoking" fat) 200Lb now, drop in a bucket for my 6'2" large frame. But jeans that used to fit tight when I was 200Lb before are VERY loose now, belt is adjusted an inch shorter then ever before and shirts start getting tights in shoulder/arm area. In other words, my body is clearly changing shape. I use supplements that are recommended for Power 90 (2 supplements, I don't remember the name) and watch what I eat, probably not as tight as I should. For a full disclosure, on top of the program I'm also going through Couch-to-5K running program, now in week 3. I swim in the pool of local gym VERY occasionally, not anywhere as often as I should...
Damn, things people would do to marginally lower their SAC
Few more month of this and I'll get a dive people get on an 80 with my slightly overfilled LP95