Runners attribute the marathon to Pheidippides, the Greek Athenian hero who ran from Marathon to Sparta to request help when the Persians invaded. Not having enough running yet, he ran from Marathon to Athens to announce the victory over the Persians in the Battle of Marathon. He then collapsed and died from exhaustion after running 150 miles in 2 days.
Even though I come up with these questions, I'm not sure how to answer it until I sit here trying to compose my answer. My question would be did he stop along the way? I picture a guy running sprinting till he got tired and then walking and sprinting again. I only read up on Pheidippides in Wikipedia and it indicates the story is improbable that a runner would make the trip when they would usually send messages over horseback but there was a mountainous pass that would have made travel by horse difficult. But let's say he did make the trip. Did he have food along the way? Did he hydrate? My guess is no because the poor guy died when he finished. Can you imagine running 150 miles, being near to death and still running to save your city? Now that is a dedicated, stubborn runner.