Saw something on tv years ago about some rural villages in Mexico where they (well the men) have this kind of football game that lasts about a week and the pitch is about 200 miles long. They play it barefoot (day and night) Someone brought them to do some ultra-marathon in the US and they got provided with shoes by one of the big companies and they hated them, had pain, ran slower and finally chucked them (and the sponsorship!)