When Tour de France champion Floyd Landis's second test came back showing higher-than-allowable levels of testosterone, he immediately denied that he had used any banned substance.
He's hardly the first athlete to deny using -- rather than own up to -- steroids.
Baseball's Rafael Palmeiro denied it, though a positive test later led to ballpark boos and retirement.
Track and field's Marion Jones was banned from some track meets because her coach dabbled in steroids.
"I'm an athlete that has always been drug free," Jones said. "I am right now, and I will always be."
Why do athletes rarely confess when confronted with hard lab evidence that they were caught cheating? Sports commentator Frank Deford says it is because high-achieving competitive athletes are used to battling and winning.
"It's easier to put the process on trial than to put yourself on trial," Deford said. " 'The laboratory's wrong. They must have gotten it wrong. The newspapers leaked it. That's not fair. Uh, the French don't like us.' "
The excuses are sometimes creative.
Barry Bonds said he thought he was using flaxseed oil, not steroids.
Olympic sprinter Dennis Mitchell claimed beer, whiskey and repeated sex with his wife the night before a race resulted in extra testosterone.
Floyd Landis blamed it on alcohol, but didn't mention sex.
"The level I have had during the Tour and all my career are absolutely natural and produced by my own organism," he said.
Cyclist Tyler Hamilton had to explain why somebody else's blood was in his veins. He claimed a vanished twin, absorbed by his body in the womb. The courts didn't buy it.
Deford says the denials will continue because athletes stick together and then the fans forget. So there is little downside for athletes who cheat and then lie about it.
"If you've got all your colleagues essentially behind you, if the public really doesn't come down as hard on cheaters as they do as, say on gamblers, on people who fix games -- as long as that is the case, then it's better to maintain your innocence," he said.