Mr. Schlubb, the pear-shaped PE teacher, sent us all out to run half a dozen laps around a preposterously enormous cinder track. For the Greenwood kids - all of us white, marshmallowy, innately unphysical, squinting unfamiliarly in the bright sunshine - it was a shock to the system of an unprecedented order.
Typically, people who exercise, start eating better and becoming more productive at work. They smoke less and show more patience with colleagues and family. They use their credit cards less frequently and say they feel less stressed. Exercise is a keystone habit that triggers widespread change.