AUSTIN, Texas -- As far as Lance Armstrong is concerned, it's all over.
The stress, the waiting, the whispers about whether he doped during his stellar cycling career, all of it ended when -- after nearly two years -- federal prosecutors closed an investigation of him last week without bringing any charges.
"I'm happy. I'm glad it's behind me," Armstrong told The Associated Press on Thursday in his first interview since prosecutors announced they were dropping the case.
The seven-time Tour de France winner said he remained confident he would not be indicted, but admitted the weight of the long investigation took a toll on him personally.
"It's not a pleasant experience ... It was difficult at times," he said. "But I was confident that we would always end up in this place."
After speaking with the AP, Armstrong participated in a teleconference with media covering this weekend's triathlon in Panama City, Panama, where he is scheduled to compete.
For the now 40-year-old Armstrong, the federal government's decision should put a stop to any allegations or rumors about performance-enhancing drug use during his career.
"It's over," he said. "I'm moving on."
Armstrong maintains he has never failed a drug test, but he nonetheless became the focus of investigators' attention after former teammates Floyd Landis accused him in 2010 of participating in a doping program.
Landis was stripped of his 2006 Tour title after failing a drug test. Armstrong won every Tour from 1999-2005.
A federal grand jury in Los Angeles looked at whether a doping program was established for Armstrong's team while, at least part of the time, it received government sponsorship from the U.S. Postal Service.
U.S. Attorney Andre Birotte Jr. announced last Friday his office had closed the case but did not give a reason.
The World Anti-Doping Agency followed up this week by urging the U.S. government to quickly hand over evidence collected in the investigation. Meanwhile, the U.S. Anti-Doping Agency's investigation into doping in cycling is continuing. When Armstrong's case was closed last week, USADA CEO Travis Tygart said he looked forward to obtaining the information developed during the federal probe.
"I don't want to get bogged down with that. I'm not concerned with that. I'm not going to worry about that," Armstrong said.
Armstrong, who has been known to attack his critics in the media and on Twitter, had only issued a muted written statement in response to the end of the investigation when the decision was first announced.
He was reluctant to talk much more about it on Thursday, but said he had a quiet celebration with his family when the investigation was closed.
"I hugged my kids, hugged my girlfriend and went and opened a cold beer," Armstrong said.
Although Armstrong was convinced that he would not be indicted, the cyclist said he was ready to fight a costly legal battle if he was.
"You had to consider all possibilities," he said.
Armstrong said he'll turn his attention in 2012 to competing in Ironman triathlons and supporting the California Cancer Research Act, a proposal to increase taxes on cigarettes by $1 a pack to raise more than $500 million a year.
He also is the founder of the cancer charity Livestrong.