Lance Armstrong will not fight charges that he used performance enhancing drugs - a decision that could see him stripped of his seven Tour de France titles.
The US Anti-Doping Agency has accused Armstrong of using banned substances dating back to 1996, including the blood-booster EPO and steroids, as well as blood transfusions.
The cyclist sued in a federal court to block the charges but lost.
He has now issued a statement protesting his innocence but confirming he will not fight the charges because of being weary of the doping accusations that have dogged him for years.
Armstrong survived testicular cancer early in his career and went on to win seven consecutive Tour de France titles from 1999 to 2005.
His decision could lead to a lifetime ban from cycling.
He retired after the 2005 Tour de France, but returned in 2009, riding for Astana Cycling and RadioShack before retiring for a second time in February 2011, taking up triathlon earlier this year.
