AUSTIN, Texas (AP) -- With stunning swiftness, the U.S. Anti-Doping Agency said Thursday night it will strip Lance Armstrong of his unprecedented seven Tour de France titles after he dropped his fight against drug charges that threatened his legacy as one of the greatest cyclists of all time.

Travis Tygart, USADA's chief executive, said Armstrong would also be hit with a lifetime ban on Friday. Under the World Anti-Doping Code, he could lose other awards, event titles and cash earnings while the International Olympic Committee might look at the bronze medal he won in the 2000 Games.

Armstrong, who retired last year, effectively dropped his fight by declining to enter USADA's arbitration process - his last option - because he said he was weary of fighting accusations that have dogged him for years. He has consistently pointed to the hundreds of drug tests he passed as proof of his innocence while piling up Tour titles from 1999 to 2005.

"There comes a point in every man's life when he has to say, `Enough is enough.' For me, that time is now," Armstrong said. He called the USADA investigation an "unconstitutional witch hunt."

"I have been dealing with claims that I cheated and had an unfair advantage in winning my seven Tours since 1999," he said. "The toll this has taken on my family and my work for our foundation and on me leads me to where I am today - finished with this nonsense."

USADA reacted quickly and treated Armstrong's decision as an admission of guilt, hanging the label of drug cheat on an athlete who was a hero to thousands for overcoming life-threatening testicular cancer and for his foundation's support for cancer research.

"It is a sad day for all of us who love sport and athletes," Tygart said. "It's a heartbreaking example of win at all costs overtaking the fair and safe option. There's no success in cheating to win."

Tygart said the agency had the power to strip the Tour titles, though Armstrong disputed that.

"USADA cannot assert control of a professional international sport and attempt to strip my seven Tour de France titles," he said. "I know who won those seven Tours, my teammates know who won those seven Tours, and everyone I competed against knows who won those seven Tours."

Still to be heard from was the sport's governing body, the International Cycling Union, which had backed Armstrong's legal challenge to USADA's authority and in theory could take the case before the international Court of Arbitration for Sport.

Tygart said UCI was "bound to recognize our decision and impose it" as a signer of the World Anti-Doping Code.

"They have no choice but to strip the titles under the code," he said.

USADA maintains that Armstrong has used banned substances as far back as 1996, including the blood-booster EPO and steroids as well as blood transfusions - all to boost his performance.

Armstrong on Thursday night dropped any further challenges to USADA's allegations that he took performance-enhancing drugs to win cycling's premier event from 1999-2005.

【新闻快讯】

美国传奇车手阿姆斯特朗于当地时间周四在个人网站上发表声明,宣布将放弃对自己服用禁药指控的申诉。声明中说“在过去的三年里,我一直在接受调查,这已经影响到了我的家庭,我的工作。”美国反兴奋剂机构(USADA)宣布将剥夺阿姆斯特朗的冠军头衔,对他终身禁赛。

对于他服用禁药的质疑,阿姆斯特朗则是极力否认,辩称美国反兴奋剂组织不具备追究他是否服用禁药的管辖全力,同时声称从美国宪法来看,反兴奋剂机构在仲裁过程中已经侵犯了他的权利。

据来自美联社的最新消息,阿姆斯特朗由于拒绝了美国反兴奋剂机构(USADA)的仲裁要求,USADA表示他们将会提出阿姆斯特朗终身禁赛的判决,并收回其所有的荣誉。

阿姆斯特朗在声明中表示,在经过多年的抗争后,自己已经“受够了”,想不受干扰地投入到为抗癌患者们的工作当中。阿姆斯特朗是一个癌症基金会的创始人,该组织将在今年10月迎来15周年庆典和累计将近5亿美元募捐的里程碑时刻。