Russia formally challenges WADA doping ban Russia contests a four-year ban from major sporting events over doping violations. The formal disagreement with World Anti-Doping Agency (WADA) will trigger an appeal process against the ban at the Lausanne-based Court of Arbitration for Sport (CAS). The head of RUSADA anti-doping agency, Yuri Ganus, warns that the legal challenge could backfire. IMAGES AND SOUNDBITES