although in all fairness the only Cathe cardio I own is the High Step workouts, BodyMax and her kickboxing. (got rid of the rest 'cause it hurt my knees all the time?!)
Okay, I admit I'm a wimp since I have no interest in Imax 3. They all make me drip buckets, but so far the worst is Power Max. It's like a non-stop jog-a-thon on a step.