So the debate about high-impact exercise bringing on osteoarthritis continues. I am a former long distance jogger/runner. Yet I come down on the side that says some types of running are too much of a good thing. My opinion is based mostly on personal observation. You can find studies to back up your argument, either way. I've read plenty of them. What I see, though, is far too many senior runners with achy joints and who look older than their years. I say exercise until the end of your days. But be smart about it. See below . . .