One thing to know is that there are spinning instructors that have never ridden outside of the spinning room. Seriously. Our instructor is one of the founders of the cycling club in town. He tries to make spinning relevant to cycling on the road. And, he does a good job. It's not as good as actual road riding but it's very worthwhile for staying in shape when combined with a weightlifting regimen. I use both to maintain muscle tone and general health.