1.Saltin, found in a 1995 study that active Kenyan school children covered on average 8–12K a day. That's a weekly total of 35–50 miles.
2.Running by itself sometimes gets a bad rap because people worry that its too much stress,” says Dr. Halstead. “But then you have kids 3 and 4 years old out on the soccer field taking soccer lessons. And research shows that a soccer player can run up to 5 miles in a single game, so its really not so different