What is the Longest Distance ever Run by a Human?

The longest distance ever run by a man was 226.2 miles. It was run by Dean Karnazes in a about 50 hours of non-stop running. He is also one of the first people to ever run a marathon in Antarctica, the coldest place on earth. Such truly long distances should not be run by normal human beings as they can cause extreme health problems if not very well trained.