10km per hour over 48 hours is absolutely insane, and the comparison with Bolt's 100m world record doesn't make any sense.

The ultramarathon world record holders today might do it : the closest existing event is the Spartathlon, a one-way Athens-Sparta race, for which the records are around 20h. Which leaves 8h of sleep before you have to do the world record run a second time...

Another decent comparison is the 48h ultramarathon. Matthieu Bonne broke the world record at 485km in 48h in 2025, the previous one being 475km.

But Matthieu Bonne is running on a flat rubber track. And both examples have modern shoes, nutrition and a support team following them.

So we are supposing our guy is world record material, even though he is selected from a population of 30k male Athenian citizen at the time. We are supposing he is running the world record twice, back to back, in sandals and without anyone to help him on the way. And/or we are supposing he is running as fast as a guy doing it on flat rubber.

It's not quite impossible (or only slightly exaggerated) but it sure as hell is absolutely insane.