In the 1920s and 30s, “Daily Dozen” was a household phrase. Some have even heard of it still today, although they may not know its provenance.
The “Daily Dozen” referred to a set of twelve calisthenic exercises that were performed, well, daily, in an attempt to stay healthy and fit.
The famous exercise routine was created by Walter Camp, a former college athlete, successful businessman, and prolific writer of books and articles on sports and the outdoors. As a student at Yale, Camp rowed, boxed, played tennis, and frequented the school’s gymnasium in his spare time. He also ran track for the university and was a varsity baseball and football player. It was that latter sport that constituted his most enduring and ultimately influential interest. First as a player, and then as a coach, Camp introduced so many innovations to the gridiron — including the line of scrimmage and the system of downs — that he became known as the “Father of American Football.”
During WWI, Camp’s athletic know-how was marshaled by the U.S. military, which made him an advisor on physical fitness. Concerned that the old style of calisthenics then employed by the troops was not sufficiently effective in getting them in fighting shape, the brass asked Camp to create a new program of exercise. His answer was the “Daily Dozen” — a short routine of physical movements designed to keep the country’s sailors and soldiers healthy and nimble, without inducing excessive fatigue.