Devildoc
Verified Military
You should check out UTMB or worse the Barkleys Marathon. Fuck that noise.
There was a show on Netflix about the Barkley event. It's an ultra, not a 'regular' marathon. And brutal. I worked with a radiologist who was into ultras, and it was the only one he couldn't finish.
It sounds cool in theory--I have done some short-distance adventure races and OCRs--but this one is just nuts.