WADA president John Fahey told The Associated Press in a telephone interview Friday that Armstrong's assertion in the Oprah Winfrey television program that he wasn't cheating when he took part in doping through his seven Tour de France wins “gives him no credibility.''

Armstrong said he "looked up the definition of cheat ... and the definition is to gain an advantage on a rival or foe. I didn't view it that way. I viewed it as a level playing field.''

Fahey said that excuse was not plausible.

“He was wrong, he cheated and there was no excuse for what he did,'' Fahey told The AP. “If he was looking for redemption, he didn't succeed in getting that.''

The WADA chief said that there was no doubt that drug-testing had improved markedly since Armstrong won the Tour de France from 1999 to 2005. Armstrong retired for two years before making a comeback in 2009, and the WADA code for drug testing adopted by most countries was instituted just before the 2004 Athens Olympics.

“Some of them (drug tests) may have been ineffective back then, but that has changed,'' Fahey said.

During the TV interview, Armstrong said ``there are people who will hear this and never forgive me, I understand that. I do.''

Fahey said Armstrong didn't appear to be remorseful.

“My feeling after watching the interview is that he indicated that he probably would not have gotten caught if he hadn't returned to the sport,'' Fahey said.