But he expects any he accepts now to be motivated to be healthy -- and to stay that way.
As a doctor who has worked closely with athletes -- including the University of Western Ontario's men's soccer team, the national rowing team and "weekend warriors" -- Shin encourages physical activity in his family practice, too.
He sometimes gives patients pedometers to record running or walking distances -- and he monitors their activity.
"I guess you could say I'm aggressive in my encouragement," he said.