After his running career, Hahn became a coach and wrote the classic book How to Sprint. He coached track and number of other Sports at Pacific University in Forest Grove, Oregon, Monmouth College in Monmouth, Illinois, Whitman College, Brown University, Michigan, Princeton University, and the University of Virginia. At Virginia he led the Cavaliers to 12 state championships in 13 years. He died in 1955, in Charlottesville, Virginia.