I've done the cardio only on a 10" step and then I've done the workout as is going heavy during the weight segments and using dumbbells when Cathe uses tubing. My favorite way of using this workout is adding power to the cardio whenever possible (side ups instead of side steps, power 3's instead of 3-knee repeaters, run ups instead of basics, etc), then when Cathe and gang go into the weight segments, I do just leg stuff: squats, lunges, plies, etc. at my own pace until they put their weights down and then I go back to cardio. It keeps the heartrate up and I feel more 'worked out' when all is said and done. Hope this helped!