Once a year, for 22 days, the world's greatest cyclists sweat and toil over 2,286 miles in France, competing for the honour of the yellow jersey which signifies victory in the toughest of all sporting events.

The man who wears that yellow jersey on the race's final day, as he sweeps gracefully through the jubilant throng on the Champs Elysees, has overcome almost unbelievable levels of physical pressures to grab the trophy which will make him famous.

For Lance Armstrong, though, Tour victory means much more.

The physical exertion pales into insignificance when compared to his bigger fight: the fight for life itself.

``It's ironic,'' Armstrong said after his maiden Tour win in 1999.

``I used to ride my bike to make a living.

"Now, I just want to live so that I can ride my bike.''

Armstrong is now targeting gold in Sydney after repeating his 1999 Tour victory by cruising home first in this Olympic year.

That he is here to compete at all is the miracle: in October 1996, he discovered he had an advanced form of testicular cancer.

It had spread to his lungs, where he had 11 golf ball-sized tumours, and to his brain.

His chances of survival were 50-50. His racing career was surely over.

Lance Armstrong, born in the small Texas town of Plano on September 18 1971, was always going to be a special athlete.

The first discipline which he embraced with characteristic ease was the triathlon.

He won an Iron Kids event when he was just 13, and a professional tournament 16 years later.

Then cycling took over. In 1989 Armstrong qualified for the junior world championships in Moscow, and two years later he capped his meteoric rise by becoming US National Amateur champion.

In his first Olympics, in Barcelona in 1992, Armstrong finished 14th and was tempted to turn professional. There he was hit by rare failure.

On his paid debut in a race in San Sebastian, Spain, Armstrong finished 27 minutes behind the winner and, worse, he finished last.

Twelve months later he was the world champion. In 1995, he won that same San Sebastian race.

He went into 1996 as the world number one.

Then came the bombshell. Forced eventually to climb off his bike and visit a doctor with excruciating pain, headaches and vomiting, Armstrong learned the awful truth.

Typically, Armstrong fought his illness in the only way he knew: head-on.

He underwent a particularly fierce programme of chemotherapy. His weight dropped and he was severely weakened.

Yet within five months of the treatment starting, he clambered back onto his bike.

In 1998, Armstrong capped his recovery by winning the prestigious Tour of Spain.

More importantly, he was seeing money flood in to the Lance Armstrong Foundation, which he had set up while in hospital to raise funds for research and awareness.

Armstrong's Tour win in 1999, only three years after his race against death itself, was simply mind-boggling.

So mind-boggling, in fact, that some fellow riders and journalists falsely accused Armstrong of taking performance-enhancing drugs.

Otherwise, what they had witnessed was not possible.

He had won the Tour by seven minutes and 37 seconds.

This year, with the world's best back in tow after the doping scandal which had marred the race in 1999, Armstrong proved himself again.

Who will bet against him in Sydney?

``If there's one thing I say to those who use me as an example, it's that if you ever get a second chance in life, you've got to go all the way.''