I've been occasionally doing spinning since I joined a gym, which was just before the turn of the year. I don't know if I was "sold" so much as I joined a gym that had it, I tried it, I like it enough to continue to do it once in a while. However I've found that it can impact my lifting schedule so I don't do it very often. Also, the gym is near the GF's place (an hour away from my place) because I have all the lifting gear needed at my place - therefore I am not always near the gym to go to the spinning class. My HRM was counting until I got into the car after class and stretching today... total count was 1018 kcal. More than 800 in class. Crazy.