Although the argument that they come from nomadic background might seem true, i doubt it because most athletes like Catherine Ndereba (3 times Boston marathon champion) who recently also took gold in the world athletic championship in Osaka is not from the nomadic tribes. Why is it that when an African perfects something we have to look at an historical reason for he / she being good at. Let me tell you why Kenyan are great athletes its because they are disciplined, focused and hardworking . They also love what they are doing so lets stop giving historical justifications. They are good from the simple reason, they work hard just like the rest, they just do it better. Simple.