p90x will kick your ass! I am in good shape and at first i could not keep up with the dvds pace. You will love it though once you get the hang of it and get into the routine. I couldn’t get the ab ripper the first two times i did it, but the next attempts i was successful. I did not keep up with the whole routine once i was able to do all of the exercises at their pace. It is basically a system a guy created that anyone else really could if you understand exercise/muscle confusion/resting periods, etc. I stopped because I did not want to pay for something I already have a lot of knowledge about. I ordered it and sent it back just to see what the big deal was. Do not get me wrong, it is a great system and there is no doubt in my mind you’ll feel great and look a lot better after completing it.
I just feel that you can make an exercise routine on your own. The problem is keeping yourself motivated. With a dvd like this though, it is easy to follow and keep yourself motivated so I would recommend it in that aspect. As far as muscle development, you will get really tone, not necessarily a lot of muscular hypertrophy (growth). If you are looking to get buff, this is not the program for you because there are a lot of repetitions performed with short rest bouts.