People often ask me "Hey, what do you think of P90X? I've seen the infomercial a dozen times and was thinking about getting it."
Well, my personal thoughts on P90X are pretty simple, so I'll try to keep it simple here.
In a nutshell it looks like a pretty good program. I should start by saying I have not purchased P90X but I do have a few friends who have used the program with varying results. Being curious about the structure, I asked a few questions and looked through some of the materials to get a fuller understanding than just what we see on television.
The program works for many of the same reasons any other workout program would work: intense circuit-style cardio program interspersed with full-body resistence training and a fairly clean nutritional approach. Any fitness approach that incorporates these elements will, in a general sense give you success (body fat reduction, increase in personal fitness levels).
The "host" and creator, Tony Horton also ads a lot to the program. He has a high energy level which should keep even the most "motivationally-challenged" people upbeat during the workout. He's also in great shape and to me, I'd have trouble buying into someone's workout advice if they aren't in great shape themselves.
My .02 cents: For those who want to do more than just go jogging once in a while and desire something faster-paced that works their muscles as well as their cardio system, yet don't have a gym or fitness club membership (and don't want one), then P90X is probably a solid investment.