Like slinke said though, 5 hours in the saddle is still crucial. If you can get outside 1 day a week for longer rides, your tushie and other body parts will thank you.

Are your spinning sessions structured? By that I mean taking a class or using Spinervals? You should do more than just sit and spin. Intervals, resistance, cadence changes, standing, one-legged spins, etc., etc., etc.