Exendine played for Pop Warner's Carlisle Indians from 1902 to 1907. Though never having played the game before arriving at the institute, Exendine was named to Walter Camp's third-team All-American team in 1906. From 1914 to 1922, Exendine coached at Georgetown and compiled a 55–21–3 record. His tenure there included a 9–1 season in 1916 and an 8–1 season in 1921. From 1923 to 1925, he coached at Washington State, tallying a mark of 6–13–4. From 1934 to 1935, he coached at Oklahoma A&M, where he compiled a 7–12–1 record.