Longest certified ultramarathon race distance

What to remember

A single block in Queens, New York, and 100 laps a day for up to 50 days: the Self-Transcendence 3100 Mile Race adds up to 3,100 miles, or 5,000 km. Launched in 1997, it is billed as the longest official footrace in the world.

For scale, an ultramarathon is any race longer than the marathon's 42.195 km. The shortest common format is 50 km, and 160 km is usually the longest distance raced in under 24 hours. Beyond that come multi-day races, over 48 hours or 320 km and more, sometimes run in stages with breaks for sleep.

The oldest and biggest ultras are run on roads, such as the Comrades Marathon, with more than 10,000 finishers every year. The Queens race works on a different scale: one city loop repeated day after day, for a distance unmatched among certified events.