I ask this because I've been wondering. Why is it that modern human beings in general tend to get injured from running. I can't think of any other animal or organism that has to stop doing an activity that it was evolved to do because it keeps getting injured. I mean, if we are designed to be able to run extremely long distances to catch prey why can't many people not run more than 50 miles a week without getting a stress fracture or some overuse injury? Are we devolving? Is it the shoes? I feel like our species is going downhill physically.