The number of Chinese racers has risen dramatically—a phenomenon that Chinese media call a “marathon fever.” Obed Tiony, a Kenyan studying at Shanghai University, works as an agent for some 300 runners from Kenya and its neighbor Ethiopia. Tiony’s is a profession that exists everywhere in the world where Kenyan runners want to compete for lucrative prizes, but China’s road-racing market, with its explosive, sudden growth, is, Tiony says, an especially strong draw for runners who hope to make a living winning prize money.