IRONMAN Switzerland Thun 2026

IRONMAN Switzerland Thun is a full-distance triathlon in Thun, Bernese Oberland. Athletes swim 3.8 km in the 17-degree water of Lake Thun, then cycle 180.2 km, and run a 42.2 km marathon. The race takes place beneath mountains, with the lake and Thun’s bridges near the action, making the setting an integral part of the day. The swim occurs in Thunersee. The bike course goes through the green hinterland, and the marathon follows Lake Thun back to the finish in town. The event was held in Zurich for over twenty years before relocating to Thun, establishing a long Swiss IRONMAN history with a recent Alpine-lake character. Competitors seek a demanding endurance test, while spectators can follow the race from the event area and watch finishers arrive exhausted after a day centered on water, hills, and a lakeside run.