Arrogant stupid fool. Life happened, age happened. You can forestall the aging process, but you cannot prevent it.
Tell that to my mom's step dad. At 75 he could still haul feed, lay brick, and turn a wrench with the best of them. He never was much of a runner though.
One of the last things I remember seeing him do was lift a Chevy 350 Turbo transmission from the floor, carry it across his three bay garage and set it on the counter. That same day I saw him load a classic VW Beetle motor on the back of a truck. He did it with no help. (He wouldn't let me help because I had a fever. He was more scared of my germs than the work.)
He was stronger than most men half his age when cancer and a stroke took him at 77. Getting old doesn't mean getting put on the shelf. Over working and over exertion are what do you in. Well, that combined with cigarettes and a bad diet.