Lance Armstrong will never win an Olympic gold medal.

The American has stood on the winner's podium five times at the Tour de France, yet in three visits to the Games he has taken just one medal home, a bronze four years ago.

On Thursday Armstrong announced he will not compete in his fourth Olympics in Athens so he could spend more time with his children.

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Speaking during his attempt to win an unprecedented sixth Tour, the 32-year-old said: "I've done the Olympics many times and if I don't have 100 percent motivation for a very important event, I don't want to take somebody else's spot."

Armstrong has been clear for the past 12 months that the Tour was his main objective this year and going home, rather than to Greece, has a lot to do with the timing of the Olympics.

The Tour finishes on July 25 and the Athens road race takes place on August 14, giving him no time to wind down.

"If you said 'OK, pick the worst day for you after the Tour de France', I might say 21 days later," Armstrong said in an interview last September.

"This year it was ungodly hot in Europe... I mean, after the Tour, you just get worn out."

Worn out or not, the fierce competitor in Armstrong will have regrets about unfinished business.

The Olympics in Barcelona were a learning experience for the Texan who finished 14th in the road race in 1992, the same year he turned professional.

In his "home" Games in Atlanta four years later, he finished 12th in the race and sixth in the time trial. Weeks later, the reason for his disappointing results became clear when he was diagnosed with testicular cancer.

Given a 50-50 chance of survival, Armstrong came through an aggressive form of chemotherapy and the rest is history. After returning to professional racing in 1998 he won the first of his five Tours the following year.

Shortly before the 2000 Sydney Olympics he broke a neck vertebra after colliding with a car during training, yet he was still favourite to take home gold in the time trial.

"In the Tour de France, the strongest man wins. The Olympic road race -- I'm sorry, but it's a lottery," he said in 2000.

"It will be much smarter for me to concentrate my training on the Olympic time trial which I think I have a good chance to win."

Armstrong finished 13th in the road race and had to make do with bronze in the time trial behind surprise gold medallist Viacheslav Ekimov of Russia, a team mate at U.S. Postal.

"If I said I wasn't surprised, I'd be lying," Armstrong said after the race. "I have a feeling this will be my last Olympics."