Whether this is the right choice for fitness for You or not (or perhaps it could be part of a combination of activities), You must keep up the fitness efforts.
Maybe padded cycling shorts might help, too wide if a saddle throws the alignment off. It will become more comfortable the more you do it. In fact I wish there were time to get back to riding again.
I once got a nasty gash on my leg because I missed the pedal in a spin class and the RPMs were high. Still have the scar. Have not taken a spin class since.
