A high school and college athlete, Yoast turned to coaching as a career. He worked in Sparta, Georgia and Roswell, Georgia before moving to Alexandria, Virginia, where he spent several decades and earned his greatest fame. Yoast coached Hammond to the Northern Virginia regional championship in 1969.
Yoast worked as an assistant to head coach Herman Boone during the 1971 season at T. C. Williams High School. During the season, the team won the state title and took a second-place national ranking.
Yoast and his wife, Betty, had four daughters: Bonnie (1951–2003), Angela (born 1956), Sheryl (1962–1996), and Deidre (born 1968).