Lance Armstrong has been stripped of his seven Tour de France titles and handed a lifetime ban by the United States Anti-Doping Agency.
Earlier, Armstrong issued a statement indicating he would not challenge USADA's charges that he had doped throughout his career, although he continues to deny he ever used performance-enhancing drugs.
While USADA can remove Armstrong's titles, such a decision could ultimately rest with the Court of Arbitration for Sport in Lausanne, Switzerland, should the International Cycling Union challenge the USADA's ruling.
But weary from years of denial, legal battles, skirmishes with former-team mates and anti-doping chiefs, it is a fight Armstrong says he no longer has the stomach for.
In a letter to Armstrong, USADA says it has blood samples from 2009 and 2010 that are fully consistent with doping.
The World Anti-doping Agency chief, John Fahey, says that Armstrong's decision not to contest the allegations adds up to nothing more than an admission of guilt.