Dee ihe na-esote maka paragraf a - Rooney nwere afọ 2011 na-akụda mmụọ, kpochapụrụ na ọkara ikpeazụ nke mita 400 na World Championships na Daegu ma mechie nke asatọ dịka akụkụ nke ndị otu Britain na 4 × 400 m relay. Na 2012 Martyn bidoro nke ọma, na-agba ọsọ 44.92s n'ọnwa Eprel na Mt. SAC Relays na Walnut, California, oge ya kachasị ọsọ kemgbe 2008. Rooney enweghị ike ijigide ụdị ahụ na-aga n'egwuregwu Olimpik nke ụlọ ya, a chụpụrụ ya na ọkara ikpeazụ nke mita 400, na-agba ọsọ 45.31. Na ọsọ ọsọ 4 × 400 mita
N'ikpeazụ, Martyn natara batọn ahụ n'ọnọdụ nke isii wee gbaa ọsọ nke 44.1 nke abụọ, mana ọ nweghị ike ịgafe Deon Lendore nke Trinidad wee bụrụ onye nke anọ.