I think the more basic point to make is that an awful lot of pilots are quite evidently less than healthy. Only a few do any exercise. Many have blood pressure issues bad enough to require permanent medication, for example.
One needs to stay reasonably healthy just to pass the medical, and good health pays dividends all the way down the line.
Things don't get any easier as one gets older; the joints get increasingly creaky, and the longer one can stay fit the better.
I haven't had a chocolate cake at the airport for many months (takes a lot of willpower)
