I work with a personal trainer and he has incorporated some elements of P90X into my work outs. I haven’t lost all the weight I want to lose, but I have trimmed down considerably and can tell that I now have muscles. It is hard work but it does the trick, especially if you can deal with the diet part of it (I’m not so good at that). The gym bought the whole DVD set so the various trainers can watch them without having to each pay big bucks for them all.