I just have to say that I LOVE spin class. I am a member at Goodlife Fitness and in January I decided that I was going to start doing Cycling class to cross train. I didn't expect it to deliver so many results. I am in-love with the intensity and the fact that the sweat just pours off you has to be a good sign. I leave feeling awesome! The results I see are the fact that hills, (which have always been a struggle for me are getting more bearable and I see physical results as well- BONUS!!. I like to do the Spin classes in the morning (6am) so I can still run in the evening.
Also added just before 2011 is Body Pump which is a class with weights. Since I have a back injury that I need to be careful about and I am not supposed to lift anything over 10lbs. Body Pump is perfect. It is low weight and a full body workout.
All in all I am trying to do two Spin Classes a week and 2 Body pump classes combined with my normal running routine. So far so good!