Between 1979 and 1987 I ran quite a few marathons, with the odd shorter races, and a few ultras scattered in. Since the fall of 1987, I've run exactly two races, a 5K each of the last two years. My fitness goes back and forth, but I've seldom failed to keep running on the weekends, and taking long walks.

My experience with over training was that it gave signals that could be ignored only willfully.