US anti-doping chief gets death threats over Lance Armstrong inquiry

• Usada tightens security after FBI called in over threats• Armstrong files to go to cycling world body this monthThe head of the US Anti-Doping Agency has tightened security within his organisation after receiving death threats during his investigation of Lance Armstrong.The Usada chief executive, Travis Tygart, told L'Equipe he had felt obliged to take stronger security measures since opening investigations into Armstrong and members of the former US Postal team."The Armstrong affa...