 Coyle boxed as an amateur winning the Irish welterweight title in 2003 after beating James Moore in the final at the National Boxing Stadium in Dublin.In July 2006, Coyle won gold in boxing at the World Military Games in South Africa.He then turned professional and had his first pro fight in March 2007, which he won at Madison Square Garden, New York on the "Erin Go Brawl" bill in which Coyle beat fellow debutant Jason Collazo by knockout in the first round on a card that included John Duddy, Andy Lee, Maureen Shea and Anthony Bonsante.