got to say the best cardio is the one that you look forward too. I look forward to karate, tennis, biking, hiking and XC skiing. Just try to keep me home when I can do the things I love. When the hubby wants a workout buddy with the cardio videos from p90x, I do it, dont wanna though. I am a bad girl becasue when I am unable to do my fun stuff, i sometimes skip cardio altogether.