I've gotten to know 2 guys in the past 6 months, both older (60's) and extreme exercisers. Think marathons, Ironman, getting up at 5 every day to run long distances.

But that's all in the past. BOTH of them seem to have really aged very quickly.

This is a pattern that I'm noticing. Extreme exercise does not seem to be linked to better health, in older age.