Idrissa Kargbo, a coffee deliverer from Sierra Leone, dreams of becoming one of the best runners in the world. It is an audacious goal.

There are no distance coaches in Sierra Leone, one of the poorest countries in the world, so Kargbo works under the tutelage of a local sprinter. Like many in the muggy, tropical climes of West Africa, he is felled by malaria about once a year: he has no doctor, but knows from the delirious fever and cold sweats that accompany the condition.

If his legs hurt, his solution lies at the local pharmacy. “I buy hot rub and put it where the pain is,” he said.

His weekly long run is 25 miles, winding through the beaches and hills and traffic-clogged streets of Freetown, where throngs of bystanders gawk and cheer. In Sierra Leone, running is an unusual pastime, as it is in most of Africa, where people gravitate toward soccer. When West Africans do take to the track, it is usually to sprint. The region churns out world-class sprinters but has had few long-distance champions.