The reason you don't get professional athletes competing is because there is no money involved so it's a bit of a waste of their training time and grant money. I think having mental determination and will to win is a bit of a prerequisite for being a pro so saying that's why they don't take part is laughable. If money comes in that will all change (look at the massive growth of Ironman for example).
A lot of professionals wouldn't have the mental determination to jog for 83 hours and not get sufficient sleep, it'd be detrimental to their body in the long term as well. The problem is from a professional standpoint is it's really just a test of who can jog for the longest with the least amount of sleep, ever heard of the tortoise and the hare? I'm not sure I'd want to sponsor an event that drives the contestants to the point of hallucination either, they're likely to hurt themselves if they don't die of exhaustion.
The problem is from a professional standpoint is it's really just a test of who can jog for the longest with the least amount of sleep