Olympic marathon champion Mizuki Noguchi will lead Japan's gold medal assault at this year's Beijing Games after being named in the country's squad.

The 2004 Athens gold medallist joins Reiko Tosa and Yurika Nakamura in the women's team, the latter selected at the expense of 2000 Sydney champion Naoko Takahashi.

Nakamura won Sunday's Nagoya marathon with Takahashi languishing in 29th place, failing to make the Japanese team for the second successive Olympics after her shock failure in 2004.

Once the darling of Japanese athletics, Takahashi's Nagoya flop has triggered renewed speculation about her future, although the 35-year-old denied she would quit the sport.

Representing Japan in the men's marathon, where they are far less formidable, will be Tsuyoshi Ogata, Atsushi Sato and Satoshi Osaki.

Tosa had clinched an automatic spot for August's Beijing Olympics after taking bronze at last year's world championships in Osaka, while Noguchi's place was never in serious doubt.

"I'm twice as happy to be picked this time round," Noguchi said. "There will be extra pressure on me as defending champion but I'm excited about that challenge."

Japanese selectors steered clear of controversy by picking Nakamura ahead of Takahashi, who never fully recovered from knee surgery last year.

"Four years ago I would never had believed I would be selected for the Olympics," Nakamura said.

"It feels like a dream."

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

Similarly hot and humid conditions are predicted in Beijing but Noguchi has been preparing for her defence with high altitude training in the Chinese mountains of Kunming.

Reuters