The formerly defiant Lance Armstrong once said, "As long as I live, I will deny ever doping," but sitting face to face with Oprah Winfrey in an interview broadcast on Thursday, he reversed course.

He lost his icy stare and buried his cutting words. Looking nervous, Armstrong admitted that for most of his cycling career he used a cocktail of drugs, including testosterone, cortisone, human growth hormone and the blood booster EPO.

But Armstrong, 41, called his doping regimen "simple and conservative", rejecting volumes of evidence by the US Anti-Doping Agency (Usada) that the drug programme on his Tour de France-winning teams was "the most sophisticated, organised and professionalised" in the history of cycling.

He justified his actions in the years he won the Tour from 1999 to 2005 on the grounds that doping was then part of the culture of the sport. He did not see it as cheating: "I viewed it as a level playing field."

Armstrong said: "There will be people who hear this and never forgive me. I understand that."

Travis Tygart, Usada's chief executive, called Armstrong's admission "a step in the right direction", but John Fahey, president of the World Anti-Doping Agency, branded it a controlled PR stunt that revealed nothing new. He said Armstrong's assertion that he was not cheating "gives him no credibility".

Former rivals, friends and sporting figures were united in their condemnation.

Robbie McEwen of Australia, a two-time Tour de France stage winner, said he could never forgive Armstrong, adding that he "deceived everybody on the planet".

Christian Bassons, who was hounded by Armstrong at the 1999 Tour for speaking out against doping, said: "He stayed the way I thought he would: cold, hard. He didn't let any sentiment show, even when he spoke of regrets. Well, that's Lance Armstrong. There's always a portion of lies in what he says."

Journalist David Walsh, who led investigations against Armstrong, said: "It didn't go far enough. He has to name names. He is probably the biggest cheat sport has ever known."

The confession strips bare the legend of the cancer survivor turned champion that inspired millions across the world. But not once did Armstrong look into the camera and say, without qualification: "I'm sorry."

The New York Times, Associated Press, Agence France-Presse