Japan's Mizuki Noguchi will ignore health fears and return to the mountains of China to prepare for the defence of her Olympic marathon title.

The 29-year-old, who won gold at the 2004 Athens Games, abandoned high altitude training in the mountains of Kunming last month after contracting a mystery rash.

But Noguchi has decided that the potential rewards and the opportunity to become the first woman to win back-to-back Olympic marathon titles outweigh the risks.

"I can't let a rash put me off going," she said. "I'm glad that my speed has returned. I almost feel like I could run track events."

The Olympic champion returned from China last month to undergo blood tests, but the results have proved inconclusive.

Noguchi stormed to gold four years ago, stunning British favourite Paula Radcliffe, who failed to finish the race in the blazing Athens heat.

Similarly hot and humid conditions are predicted in Beijing but Noguchi has been preparing with punishing high altitude training in China.

Reuters