By JERÉ LONGMAN

Olympic marathon runners are no less obsessed about shoes than the women from “Sex and the City.”
Ryan Hall and Deena Kastor of the United States began testing the latest design from the distance-running equivalent of Manolo Blahnik. Their shoemaker is a Japanese master craftsman whose soles are renowned not for space-age gels or air bladders but for the gripping properties of rice husks.
The racing flats, with husks ground and imbedded in the rubber soles, are designed to absorb water and to provide up to 10 percent better traction along the 26.2-mile marathon course at the Olympics in August.
The soles are custom made for a handful of elite runners by Hitoshi Mimura, 59, a former marathon runner who is a master craftsman for Asics, the Japanese sporting goods manufacturer.
“The Olympics are the epitome of running,” said Ms. Kastor, a bronze medalist in the women’s marathon at the 2004 Athens Olympics . “There is a very small margin of error in preparing and racing. You try not to leave any stone unturned. Those fractions of a second add up.”
Shoes with wet-grip soles designed by Mr. Mimura were on the feet of Mizuki Noguchi of Japan when she ran through the streets of Athens to win the women’s marathon at the 2004 Summer Olympics. Ms. Noguchi was quoted in a Japanese news report as saying that she slept with the rice-husk shoes next to her pillow the night before her victory.
At the finish line in Athens, she took off one of her racing flats and kissed it. Later, she called Mr. Mimura the “god of shoes.”
Ms. Noguchi said she would wear an updated version of her “magic shoes” to defend her title in Beijing.
“I’m looking for a shoe to get excited about,” Mr. Hall said. “If you’ve got a shoe that somebody wants to sleep in the bed with, that’s a pretty good shoe.”
When Ms. Kastor first met with Mr. Mimura in 2001 at the world track championships, he spent 20 minutes measuring her feet, including the length and circumference of each toe, the width of her heel, the length of her Achilles’ tendon and the width of her foot at six or seven spots. “I didn’t know you could get that many measurements for a foot,” she said. “But the shoes he made fit like a glove.”
Shoe selection for the runners is a important, because the Beijing course could become slippery from rain, slick at water stops and misting stations, and glassy along a four-mile stretch of stones that have a feel similar to marble.
Even under the best of circumstances, marathon runners face sore and swollen feet, blisters and the occasional wandering toenail.
“Samurai cannot fight without their swords,” Mr. Mimura said. “It is the same for runners and their shoes.”