An ultramarathon is a footrace longer than the traditional marathon distance of 42.195 kilometres (26 mi 385 yd). The sport of running ultramarathons is called ultra running or ultra distance running. . Various distances, surfaces, and formats are raced competitively, from the shortest common ultramarathon of 31 miles (50 km) and up to 3100 miles. Around 100 miles (160 km) is typically the longest course distance raced in under 24 hours, but there are also longer multiday races commonly held as 48 hours, 200 miles (320 km), or more, sometimes raced in stages with breaks for sleep.
https://en.wikipedia.org/wiki/Ultramarathon
An ultramarathon is a footrace longer than the traditional marathon distance of 42.195 kilometres (26 mi 385 yd). The sport of running ultramarathons is called ultra running or ultra distance running. . Various distances, surfaces, and formats are raced competitively, from the shortest common ultramarathon of 31 miles (50 km) and up to 3100 miles. Around 100 miles (160 km) is typically the longest course distance raced in under 24 hours, but there are also longer multiday races commonly held as 48 hours, 200 miles (320 km), or more, sometimes raced in stages with breaks for sleep.
