Malcolm Gladwell considers the culture of long distance running in Kenya. An excerpt:
We've always known that running is culturally important in Kenya, in a way it isn't anywhere else in the world. But these are staggering numbers. A million 10 to 17 year olds running 10 to 12 miles a day? I'm guessing the United States doesn't have more than 5,000 or so boys in that age bracket logging that kind of mileage. 70 miles a week is an enormous amount of running--even for an adult. I ran middle distance at a nationally competitive level as a teenager, and never got close to 70 miles a week.