What I love most about the OTF workout is that it is constantly changing and challenging your cardio output as well as all of your different muscle groups to be sure that you get a whole body workout. I've found myself going from a walker to hitting 9mph 30 second all-outs when I thought I'd never run again! (In 3 months of faithfully taking 2 classes per week.) I love the creatively themed classes and playlists too! It's just FUN! The feedback of the screen and HR monitors keep you honest! Positive feedback on real time, love it!
That it's slightly different every time, that you keep track of effort/output and that I can decide what's a push/all out given how I feel on a particular day (coaches aren't yelling at me to go behind my capabilities)