Sounds like guys of that caliber won't even break sweat over that distance

10-12C is a lovely temperature for running. I've just come back from a 15 mile run along the local leisure trail this morning at around 10C and didn't even take my jumper off for the whole run. Very pleasant and enjoyable. It's actually easier to run that distance than walk it (plus it takes a lot less time!) as there's something about a running gait that uses less energy for a given distance (once you've got past the gasping for breath stage anyway). A few years ago one of the local fitness trainers set himself a charity challenge of running the local roads for 24hrs and did it wearing a tuxedo. He covered over 100 (dry) miles and at the end he looked like he was just going out to dinner - not a hair out of place, still wearing the tie etc. Different league to me but then again he was 40yrs younger.

The Moab 240 looks like an interesting event. I was in Moab on a bike trip a few years ago and know what the terrain around Canyonlands and Arches is like. To have the people on that event heading out to run 240 miles contrasts nicely with signs at some of the tourist sites warning about the consequences of setting off on a half mile hike without the correct clothing, sufficient water and a fully charged phone. Most people didn't bother. If they couldn't see it from their cars they weren't interested. 100m from the car park and the trails were deserted.