Armstrong Comes Clean: Admits Doping Throughout Career

Lance Armstrong Admits Drug Use, Bullying; 'It's a Major Flaw' (Chicago Tribune News)

Lance Armstrong finally confessed his doping sins to talk show host Oprah Winfrey on Thursday but the United States Anti-Doping Agency (USADA) has now challenged the disgraced cyclist to do the same under oath.

USADA, who exposed the seven-times Tour de France winner as a drug cheat, said in a statement that Armstrong's admission to a worldwide television audience was a good first step but that the 41-year-old needed to do more.

In this handout photo provided by the Oprah Winfrey Network, Oprah Winfrey speaks with Lance Armstrong during an interview regarding the controversy surrounding his cycling career January 14, 2013 in Austin, Texas.

"Tonight, Lance Armstrong finally acknowledged that his cycling career was built on a powerful combination of doping and deceit," said USADA chief Travis Tygart in a statement released shortly after the gripping 90-minute interview.

"His admission that he doped throughout his career is a small step in the right direction.

"But if he is sincere in his desire to correct his past mistakes, he will testify under oath about the full extent of his doping activities."

Armstrong, who has been stripped of his seven Tour wins and a bronze medal from the 2000 Sydney Olympics, took Winfrey's quickfire, probing questions head on, owning up to the type of drug use that has tainted the sport he said he loves.