The Scotsman met up with the lecturer, who raised money for charity after completing 30 marathons in 35 days this summer, despite suffering from seizures.
"He told me on the 20th day he fell," said Murray. "He had a fit, a seizure, and had a hairline fracture in his leg and continued to do it.
"It was pretty cool speaking to someone like that. He obviously loved tennis. I went back with him to our hotel. [Juan Martin] Del Potro was there so he was pretty pumped."
The US Open champion is currently taking on Novak Djokovic at the ATP World Tour Finals in London.