Taken from a P.E. book from 1855:
"For every step tresses a new tide of blood from the great central organs to the extremities and overspreads and penatrates the entire system with fresh importations of strength and vivacity. Let the poor student, half dead from poring over his books, get up and spend 30 minutes in vigorous and various movements of the arms, feet and trunk and he will already gain so much more quickness of mind, that he will be more than compensated for any loss of time."