So, I was watching the Belmont Stakes today, which got me thinking: though a horse could obviously outrun any human over shorter distances, what if the race was longer? say, a marathon, or 50K, 50 miles, whatever. Over such a long distance, would a human be able to beat a horse, by virtue of better endurance? What do you think the shortest distance would be over which a human runner would win? (Assuming, say, that the human is one of the best in the world, and that the horse is a fast thoroughbred.)