Olympic marathon runners are no less obsessed about shoes than the gal pals in “Sex and the City.”

Later this month, Ryan Hall and Deena Kastor of the United States plan to begin 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 husks, which are ground and imbedded in the rubber soles of racing flats, are designed to absorb water and to provide up to 10 percent better traction along the 26.2-mile marathon course at the Beijing Olympics in August.