Defending Olympic champion Mizuki Noguchi will not run in the women's marathon race at the Beijing Games because of an injury she picked up during recent training, officials of the Japanese Olympic delegation said Tuesday.

The Japanese Olympic Committee has accepted a medical certificate on her injury and a written request from her to withdraw from Sunday's race, noting that the 30-year-old has hurt her left hamstring and groin muscle. There will be no replacement for her, the JOC said.

Noguchi, 30, returned to Japan from altitude training in St. Moritz, Switzerland, on Aug. 4, ahead of her original schedule, citing fatigue.

On Sunday, Noguchi's coaches and JOC officials confirmed that she had complained of pain in St. Moritz on July 25 and efforts had been made to help her recover from the injury as quickly as possible through injections and other treatment since her return to Japan.

Officials close to the situation said she has been recovering gradually from her injury and has resumed workouts.

"It was a result of her vigorous quest for a second straight gold medal, and we can do nothing about it," said Susumu Takano, head coach of the national athletics team. "What we have to do now is to bounce back from this setback and produce results in our campaign here."

In Sunday's race, world bronze medalist Reiko Tosa and up-and-coming Yurika Nakamura will represent Japan.