Honorable Mention: Novemberkasan
Before heading into the top five, we wanted to give an honorable mention to the longest-running extreme endurance race in the world—a race you may or may not have ever heard of. Novemberkasan is an annual Swedish event that takes place during—you guessed it—November, and has been going on since 1915. Regardless of the terrain, battling wintery Nordic conditions in the dark (yeah, not much daylight that time of year) is extreme in itself.
Novemberkasan has slowed to a simmer in the past few years, with the field now limited to 200 riders, most of whom reach the finish rather easily. Riders complete one lap during the day and then complete another two laps at night. The Kasa (trophy cup) is awarded when a rider wins the event three times. This year the Kasa looks likely to go to Husqvarna rider, and modern-day Viking, Joakim Ljungren, who already has two wins under his belt.