 Bush began competing as an amateur kickboxer in 1979 and amassed a record of 15–2 with 11 knockouts over the next four years before turning professional in 1983.The highlights of his amateur career include decision wins over Darnell Studavent for the Virginia Welterweight (-67 kg/147 lb) title and Alphonzo Claiborne for the Virginia Super Welterweight (-70 kg/154 lb) belt in 1981 and 1982, respectively.His professional kickboxing debut came on June 11, 1983, in Memphis, Tennessee when he knocked out the previously undefeated Jackie "Hollywood" Dixon 8–0 (5 KO's) in round two of a bout televised nationally on ESPN.