My knees are sore also (had to abandon my running routine for fear I'd really have serious problems). I think you can modify and still keep up with the program. For example, during the alternating knee thrusts of Cardio 2, I take a couple of little steps to adjust the direction of my leg instead of the slide/swivel I see everyone doing on the DVD. Is there is anything you can do comfortably? Since many of the exercises are beginning to combine upper and lower body at this point, you might find a way to adjust and keep the upper body activity going. I know you didn't have much to lose, you'll probably still benefit from most of the toning/strength aspects of the program even if you modify to your comfort level.

I've had to modify several moves. When phase 2 cardio came around, I quickly learned that I would have to do any dvd I have. My knees absolutely couldnot take this kind of pounding 6 days a week. I will say that I have gotten much stronger, so we'll see what phase 3 brings. I did end up getting the new Turbo Fire "fire starter". It doesn't have any jumpimg, but still a very intense w/o.