[QUOTE=Samurai Jack;857110]For what it’s worth, the P90X people I’ve seen look like they put on a bit of muscle. On the other hand, the science of what they do logically runs counter to that, and it could be an illusion brought on by decreased bodyfat.
For example, working out six days a week will not give your body time to build muscle before the next workout as it’s still trying to recuperate from what you did the day before. I know that Horton claims this is bypassed by the variable workouts, but it dosen’t hold up in a lab. It’s well understood that physiologically you can only systemically sustain stressful workouts (dosen’t matter if the source is weights, yoga, cardio etc.) for so long before you start to catabolize muscle.
I know that I can hardly recover between the martial arts and weights that I do now, so I don’t think I could handle P90X on top of it.
Still, I’m curious to see where David goes with it, because he obviously knows what he’s doing…[/QUOTE]
Well, this is not actually the way it is.
you do have extreme variation between cardio light and heavy, to yoga to weight lifting.
you do have recovery weeks at the end of each cycle and combined with the portional recovery of the variation, this does work. I am just finished week five and yes, you gain muscle and lose fat at the same time, like any other rigourous routine will do.
so, you basically have a recovery day every week and a recovery week every month.
Horton does understand that exercise is the architect and rest is the builder. I think he actually puts it in those terms.
Seriously, my only issues with p90x is that Horton talks too much during the sessions, but luckily, you can Mute him! hooray! hahaha.
There is a lot of things in these routines that I will be taking with me into the future.
Best 100 bucks i spent, it’s a cool system and if you commit, it will deliver.
I do not recommend the program for anyone who isn’t already in decent shape, so if you are slightly obese and not really much of an exerciser, this would be a terrible buy for you. It would kill you on day one and then gather dust. lol 
so, keep that in mind if yer gonna give it a go.
I’ve lost 8 lbs in and gained same in muscle. cool eh. 5 weeks girls, 5 weeks! 7 to go and then i’ll cycle into a more rigourous MA cycle that will really tick off my training partners. hahaha.