Dear Lollie,
These are the cardio combinations I do with the CTX series: 1. I do all the cardio on All Step + all the cardio on Step & Intervals & 2. I do all the cardio on 10-10-10 + all the cardio, etc. on Power Circuits. I just got a DVD player & these workouts on DVD, but I haven't gotten too fancy with the workouts. These combinations suit me really well, though. I hope this helps!
Jeni