Paula Radcliffe, the marathon world record-holder, has confirmed that she will race at the Olympics “unless my leg breaks down”.

The Briton fractured a femur in the build-up to the Games and was told by doctors that it would be impossible for her to compete.

Radcliffe never lost hope, however, and is determined to complete a remarkable recovery with victory in the marathon in Beijing.

"I'm racing unless my leg breaks down," Radcliffe said. "The aim has always been to start the race. Everyday I go out and plan to start the race. I'm getting more and more confident because every day you run more on it and it gets stronger."

"I feel good. I feel happier even to be at this stage. I know from the stuff that I've done that I'm in good enough shape to be on the start line."

Radcliffe dropped out of the marathon at the 2004 Athens Games, but she won the world championship title in the event a year later in Helsinki, Finland.

In February, she won the Laureus award for World Comeback of the Year for winning the New York Marathon after two years away from competition following childbirth.

She set the world record of 2 hours, 15 minutes, 25 seconds at the London Marathon in 2003. She also won the London race in 2002 and '05.

"I don't know but I guess I'm probably not in 2:12 shape, but I think if you put yourself on the start line, you're in with a chance," Radcliffe added.

After arriving in Macau to join up with some of the Team GB athletes today, Radcliffe faces 11 days of acclimatisation that will prove to her and her coach, husband Gary Lough, whether she is ready to compete.