 Born in Portland, Oregon in a Catholic family, Rupp set junior and American high school records, while competing for Portland, Oregon's Central Catholic High School.Originally a soccer player, he caught the eye of American marathon legend Alberto Salazar, who coached him to great high school success, including two Oregon state titles in cross country (2002 and 2003) and three individual championships in track and field (1500 m in 2004 and 3000 m in 2003 and 2004).After winning the Oregon state title in cross country in 2003, he went on to finish second nationally in the 2003 Foot Locker Cross Country Championships.