United States Anti-Doping Agency Chief Executive Officer Travis Tygart, right, during a subcommittee hearing on drug use in sports in 2008. Susan Walsh/AP hide caption

itoggle caption Susan Walsh/AP

Lance Armstrong, wearing the yellow jersey that identifies the leader in the Tour de France, during the race in 2003. He won that year and six other times. Joel Saget /AFP/Getty Images hide caption

itoggle caption Joel Saget /AFP/Getty Images

Lance Armstrong grimaces prior to the start of the third stage of the Tour de France cycling race in Wanze, Belgium, on July 6, 2010. Armstrong said Thursday he is finished fighting charges from the U.S. Anti-Doping Agency that he used performance-enhancing drugs during his unprecedented cycling career. Christophe Ena/AP hide caption

itoggle caption Christophe Ena/AP