ÖTILLÖ Colorado

ÖTILLÖ Colorado is a swimrun event held in Colorado on October 4, 2026, part of the ÖTILLÖ World Series circuit. Three formats are offered: the World Series course of 37.8 km (about 23.5 miles), the Sprint at 17.7 km (about 11 miles) and the Experience at 9.7 km (about 6 miles), each alternating running and open-water swimming sections.

Swimrun is its own discipline: you run in your wetsuit and swim in your shoes, usually tethered to a partner, and the transitions between water and trail are where races are won or lost. The Experience distance is the right entry point if you have never mixed the two sports, while the Sprint suits runners with solid swimming skills who want a half-day effort. The World Series distance calls for real endurance in both sports and a well-rehearsed partnership. Whatever the format, give yourself at least 12 weeks of combined training, practice open-water swimming with paddles and a pull buoy, and do several brick sessions in your race kit so nothing is new on race day. Remember that Colorado altitude will make both the swim and the run feel harder than at sea level.