My wife and I exercise a few days a week with a video DVD, simple stretches and balance movements help with aches,,Im 73 and she is 60. Biking helps here osteoarthritis in her knees and she rides now like the wind...
Yeah, stretching is key. I'm doing it daily now, especially the IT band and my piriformis. I'm glad cycling helps your wife's knees. I thought it would be good for mine, but apparently I managed to injure both meniscuses (meniscusii??). The second one seems to have finally healed up and now I'm focused on prevention (which I probably should have been all along, dumb me). I did get a cadence sensor to focus more on easier rotations rather than mashing for speed. The things we learn....even as we get LOTS older, lol. Keep on riding =).