Ngong, Kenya (CNN) It’s early morning in the Ngong Hills, on the edge of the Great Rift Valley, and a group of athletes huddle together in prayer in tracksuits and long pants. It’s notoriously chilly this time of year.

The runners set off from their camp, a converted orphanage, at a modest pace, hopping over puddles and dodging boda boda bikes.

Ngong is a haven for Kenyan runners, the most storied middle-distance champions on the planet, and it’s not unusual to bump into an Olympian on the dirt roads here.

Rose Nathike Lokonyen, a refugee from South Sudan, training on the Ngong track on the outskirts of Nairobi. (Picture: UNHCR)