“It is widely accepted in the literature that athletes of West African origins achieve the best sprint performances, while athletes originating from East Africa are the most efficient at long distances. So far, no study has measured the evolution of these groups’ contribution from 100m to the marathon.”

“Speed, morphology and geographic origin of the top 100 male and female athletes (from 100m to the marathon) were collected and analyzed over the 1996-2012 period.”

“The amount of male sprinters (100, 200 and 400m) originating from West Africa increased from 57.7% in 1996 to 72.3% in 2012….”

“….female sprinters from West Africa increased from 55% to 65% over the same period.”

“For long-distance runs (3000m, 10,000m and marathon), male athletes from East Africa represented 32% in 1996 ; this proportion increased to 65.7% in 2012.”

“It also increased over the same period from 9% to 39% for women.”

A. Marc, et al
Geographic enrolment of the top 100 in athletics running events from 1996 to 2012
Journal of Sports Medicine and Physical Fitness — Volume 57 #4 — page 418