Well, I attempted to do Kenpo X, today, in spite of my back hurting me. Was not a good idea and just made the back injury worse. I’m not sure if I hurt my back as part of one of the P90X workouts or not, because I have back pain, occasionally, anyway. Likely due to the fact that I’m way too overweight to begin with. 
Regardless, you must listen to your body. There’s a difference between the pain produced from muscle workouts and injury pain. I tried to push too hard with this P90X workout. Now, I’ve pushed too hard and must sit out for one of the daily P90X videos and maybe miss more days. Take it easy! Modify, modify, modify and listen to your body.
Kenpo X is similar to boxing and is one of the more aerobic workouts in P90X. Because of the “boxing” style to the exercises, you end up moving your hips in twisting motions quite a bit and that’s what really started to irritate my back. The pain became worse and worse until I could not stand up, even with modifying the exercises. I knew it was time to quit, as much as I hated to do so.
Now, I have a couple options: (1) Pick back up, tomorrow (not likely) or (2) Take a couple days off and start back where I should in the program to be sure my back has time to recover (the smart thing to do).
I probably should not have done Kenpo X, today, as my back hurt before starting the DVD. However, I was hoping it was just muscle pain and that the workout would help get the kinks out. Unfortunately, the workout made the pain worse. Tomorrow’s a rest day, anyway, so maybe I’ll be ready to go in a couple days. I’ll let you know!
I know this is typically one of the favorites among people doing the program, but I’m not a fan, especially. I like Plyometrics much better.
To get your own copy of P90X: http://bit.ly/P90XTruth