'Don't cry for me', says defiant Lance Armstrong

Lance Armstrong was back on his bike on Saturday, urging his supporters not to 'cry' for him a day after the United States Anti-Doping Agency's (USADA) decision to strip his seven Tour de France titles and ban him for life.

In his first public appearance since announcing he would no longer fight doping charges brought by USADA, Armstrong finished second in a 36-mile mountain bike race in Aspen, Colorado, five minutes behind a 16-year-old rider, Keegan Swirbul.

Wearing sunglasses and black and gold riding gear adorned with sponsors' logos, Armstrong appeared unfussed by the media throng that had travelled to the mountain resort amid concerns his legacy has been irrevocably tarnished.

"Nobody needs to cry for me. I'm going to be great," Armstrong told reporters.

"I have five great kids and a wonderful lady in my life. My foundation is unaffected by all the noise out there.

"I think people understand that we've got a lot of stuff to do going forward. That's what I'm focused on and I think people are supportive of that. It's great to be out here," he said.

Despite giving up the fight against the charges, Armstrong has maintained his innocence and railed against what he says is an unfair witch-hunt.

The Texas-born cyclist, who famously beat cancer and whose foundation Livestrong has raised hundreds of millions of dollars in the fight against the disease, has retained major sponsors and enjoyed the backing of many key cycling figures.

Others, including WADA chief John Fahey, say his failure to contest his charges can only mean he is a drug cheat who has defrauded the cycling tour, his rivals and millions of sports fans for over a decade.

The Armstrong case has yet to rest, with cycling's global governing body, the International Cycling Union, demanding USADA hand over its evidence. The Court of Arbitration for Sport could ultimately have a final say on his guilt or innocence.

The retired Armstrong said he was no longer concerned about racing.

"It's more about staying fit and coming out here and enjoying one of the most beautiful parts of the world, on a beautiful day, on a very hard course," said the 40-year-old.

"Some may say you're a little sick to spend your free time doing stuff like this. I had a good time."

Armstrong remained the 'seven-time Tour champ' to teenager Swirbul. "I'm so psyched right now," he said. "I wanted to win this race so bad."

Donations to his foundation on Friday were up more than 20 times their daily average, Livestrong staff said, and Armstrong received positive crowd support in Colorado.

"The people like the people who are standing around here or on the course, they voiced their opinion in the last 48 hours and are going to support us," Armstrong said, adding that the future of cycling was in good shape.

"It's cool to get your butt kicked by a 16-year-old when you know he has a bright future," he said.

"There are a lot of good young guys. Cycling is going to be fine."