Kastor going for win

Since Joan Benoit won the inaugural Olympic women's marathon at the 1984 Los Angeles Games, U.S. women have rarely featured in international championships or big city marathons.

Kastor's third place in the searing heat and stifling humidity of the 2004 Athens Games was the first U.S. Olympic women's marathon medal since Benoit's victory in equally demanding conditions and the 33-year-old American is now poised to win her first major race.

World and three-times London champion Radcliffe, who withdrew from this year's race with a foot injury, exploded the myth that African women have an inbuilt genetic advantage over long distances.

Intensive training and an iron will made Radcliffe into a world champion in Helsinki last year after she dropped out of the Athens race with a stomach complaint and Kastor has been following her example.

Kastor set an American record while finishing third in the 2003 London race after winning the world cross-country long-course silver medal for the second consecutive year.

"I have always been an aggressive runner," the 9-4 favourite told a news conference on Thursday. "My aim is to run hard and run a negative split."

After Sunday's race, Kastor plans to concentrate on track running this year although her long-term goal is the 2008 Beijing Olympics.

"I am going to cut down on my running and get some speed back into my legs," she said.

Kastor's rivals on Sunday include former world half-marathon champion Berhane Adere of Ethiopia, an accomplished track runner either outdoors or indoors on the boards.

Adere, 32, will be running her first serious marathon and on Thursday she said she would consider a permanent switch to the roads if she ran well at the weekend.

"If I get a good time on Sunday I will think seriously about the marathon in the future," she said.