I just did Basic Step for the first time, and though I'm not a stepper, I am an advanced exerciser. Using an 8" step I had no problem getting into and staying in my cardio target zone. I decimated my calves though. Forgot to stretch them, and I've been limping for days. :-( If Basic Step were a little longer, without so much warm-up, I would consider it to be a perfectly good cardio workout.