Spinning does help your breathing condition, that what made me stronger, the rest like cadence, climbing and speed comes from training outside, mostly with a group which challenged me. I ride between 100 and 150 miles a week.

In the moment I have to use the gym spin class, it is just to cold outside. The spin instructors we have in our facility are non bikers, so you know what you get, but hey, I can make it as hard as I want, and I can change the excersise... I just like the group dynamic, that's the reason I am there, other wise I would train at home.