I think people can handle 150 to 200 miles a week. But something has to give somewhere. If he's a student, how's he going to study? He may be at the age of chasing and courtship, and that's an important form of sport and recreation, too.
A teacher is never too smart to learn from his pupils.
It's easier to beg forgiveness than ask permission.
God determines how fast you're going to run; I can help only with the mechanics.
Everything you need is already inside.
I still bother with runners I call hamburgers. They're never going to run any record times. But they can fulfill their own potential.