ATHLETICS-MARATHON-KEN

A group of runners takes part a training session on March 13, 2019 in Iten, Kenya. - As dawn breaks high in Kenya's Rift Valley, car headlights pick out groups of elite athletes, mere silhouettes on roadsides as their grinding daily training routine gets under way. Hitting the tarmac under a wan rising sun, the athletes take advantage of the cardiovascular benefits from training at an altitude of 2,500 metres (8,200ft), which boosts oxygen-carrying red blood cells. There are dozens of similar camps up and down the Rift Valley, and they have churned out some of the best distance runners the world has ever seen. (Photo by FRANCK FIFE / AFP) (Photo credit should read FRANCK FIFE/AFP via Getty Images)