I recently found out I have mild arthritis in both knees, and the ortho recommended exercise. As in either a stationary bike, or elliptical, and as I am a former competitive swimmer, swimming. So I looked at the Y near my house, and the one near my office, to see how much, what they offer, etc.
The driving me up the wall part is the majority of the aqua and other fitness classes are held during the day, with very few after working hours. Now if there were enough offered, at times that would work for me, I might have joined and made the effort. But as there aren't, I'm back to square one. I have 2 jobs and work about 60 hours a week, so I have limited time as it is, which also makes it tough.