@imhikarucat
>33km(20mi)
it might take as little as 2 hours to do.
may I introduce you to the wonderful world of ultramarathonners, or Ultras, basically any race longer than 42.195 kilometres (26.219 miles) which could include races as long as 1600 kilometre (1000 mile) and ran over a couple of days, on minimal sleep and stoppage time on very hostile terrain.
https://en.wikipedia.org/wiki/Ultramarathon
The human body is a formidable thing.