I don't know the answer to this question (I did know a multiple World Champion on the track who did spin classes in the winter.), but if the most common reason for doing something is it is better than not doing anything at all, I consider rather dubious. If I am going to spend time on something with a goal of improvement, I am going make sure that activity to make sure that it will definitely do what I want it to do.
Last edited by colnago62; 01-24-15 at 12:28 PM.