 As a reaction to the discovery that so many World War I recruits were unfit for service, he initiated at Harvard one of the first collegiate fitness programs in 1919.He was Professor of Hygiene from 1914 to 1924 and later served as a member of the Harvard Corporation from 1931 to 1954.He played a prominent role in several medical organizations, notably as President of the American Medical Association in 1945-46.