Sydney Olympic women's marathon gold medalist Naoko Takahashi may have to sit out domestic qualifying races for next year's World Championships after suffering a fractured ankle at a training camp in Colorado.

The 32-year-old, who returned to Japan from her base camp in Boulder on Saturday, said she twisted her right ankle during practice and tests last month revealed she had fractured a bone and would need six to eight weeks to fully recover.

Takahashi, who was overlooked for selection to the Japan team for the Athens Olympics this summer, is expected to be able to start running in two weeks.

However, she may not have sufficiently recovered in time to run in Osaka in January and in Nagoya in March, both of which serve as qualifiers for selection to the Japan team for next year's World Championships in Helsinki.

"When I found out that I'd broken a bone it came as a great shock to me," Takahashi told reporters at Narita airport.

"So many things have happened to me this year. But I've bounced back quickly. If possible, I want to run one (marathon) as soon as I can."

Brazilian eyes Biwa

RIO DE JANEIRO (Kyodo) Brazilian Vanderlei de Lima, who won the bronze medal in the Athens Olympics men's marathon despite being attacked by a defrocked Irish priest, is considering taking part in next year's Lake Biwa Mainichi Marathon in March.