About a decade ago I met some 80+ cyclists (club name "The Wobblies") and they advised me, "Don't ever stop." At 62, I intend to keep following that advice.
All those decades of bike commuting, those trips in harsh weather and many winters of night cycling both ways, I never considered the long-term benefits I'm seeing now. I just did it because it was better than driving.
My best tour ever (so far) was at age 55. I think I finally figured a lot of things out, including the concept of "delayed gratification."
Unfortunately, diseases affect many of us, at all ages. Do what you can with what you have.