The same organization has one here in NYC that is nearly 5000km, running around a single block in Jamaica, Queens, over the course of 52 days: <a href="https://en.wikipedia.org/wiki/Self-Transcendence_3100_Mile_Race" rel="nofollow">https://en.wikipedia.org/wiki/Self-Transcendence_3100_Mile_R...</a>
For anyone in the northeast, i can recommend Three Days At The Fair [1], the longest duration of which is actually 6 days and the course is a 1 mile loop around a state fair ground in New Jersey. I did a mere 12 hour option on the final weekend, and the suffering of those competitors on their 5th/6th day is something i will never forget. Sideways leans, some quite pronounced, others moving backwards to alleviate pains developed moving forwards etc.<p>Why do they do it? Well, the camaraderie is incredible. Much of the course is lined where runners have pitched their tents/campers/chairs and the support, sharing of food, stories and beer make it a unique event. The shortest duration is 6 hours and you’re not obliged to run more than a single loop/mile if you don’t want to.<p>[1] - <a href="https://sites.google.com/site/njtrailseries/fair" rel="nofollow">https://sites.google.com/site/njtrailseries/fair</a>
Reminds me of Beau Miles' "24 marathon" which was much more fun: <a href="https://www.youtube.com/watch?v=EvT5XS7j-Dc&t=6s" rel="nofollow">https://www.youtube.com/watch?v=EvT5XS7j-Dc&t=6s</a>
Relatedly, see Big's Backyard Ultra[0]: runners run a 4-mile loop, on the hour, every hour, 24 hours a day, until only one runner completes a loop that nobody else does. In 2011, when it started, the winner did 18 laps. In 2023, the winner completed 108 laps!<p>[0]: <a href="https://en.wikipedia.org/wiki/Big%27s_Backyard_Ultra" rel="nofollow">https://en.wikipedia.org/wiki/Big%27s_Backyard_Ultra</a>
> it's the most pure running format.<p>Pro-tip: stay clear from anyone who makes these comments. Someone sold them a philosophy and they are too financially deep into it to back down.
On skateboards, it's called an Ultraskate: <a href="https://24hourultraskate.com/" rel="nofollow">https://24hourultraskate.com/</a>