i've heard his running form is absolutely flawless, which is a big part of his longevity. unlike the retarded joggers you see flailing down the street in the morning like headless chickens who shock their entire body with each step.
he also orders pizzas ahead of time to certain intersections and times it so he'll pick it up right when he makes it there. then eats it while he's running. also running 50 miles a day would require about 8,000 more calories above your BMR