The Inferno Triathlon is a triathlon event held in the Bernese Oberland every August since 1998. Unlike many other triathlon events, the necessary infrastructure is not provided at a central location; instead, the start, transition zone, and finish are all in different places. The start of the triathlon is in Thun; the transition zones are in Oberhofen, Grindelwald, and Stechelberg; and the finish is on the Schilthorn. The start of the half-marathon is in Lauterbrunnen, and the athletes’ village is in Mürren, which is also the finish for the Team Trophy.
The triathlon first involves a 3.1 km swim in Lake Thun followed by 97 km on a racing bike and 30 km on a mountain bike. The final section consists of a mountain run over 25 km. With 5500 meters of ascent, the Inferno Triathlon is regarded as one of the toughest triathlons in the world. Besides the triathlon itself, there is also a number of less demanding competitive events on offer.
