Buster Martin finished the Flora London Marathon in just over 10 hours, but according to this report, he may not in fact be 101 years old, his name may not be Buster and he may not have fathered seventeen children.
On a side note, the article says the Guinness World Record for the fastest marathon dressed as a superhero is 3 hours and 4 minutes. So the only question is: which superhero do I choose?