Triathlons are considered among the most challenging sporting events in the world. The race, which combines swimming, cycling and running, was invented in Hawaii and would not seem to lend itself to conditions in Berlin, which is freezing for half of the year. Triathlon clubs persist in Berlin, however, and people train year-round in indoor swimming pools. Ironman level is a 3.8km swim, a 180km cycle and 42km run. Olympians compete with 1.5km swim, 40km cycle, and 10km run. Most beginners start with ‘sprints’, which combine the three sports but at much shorter distances. Those who don’t like to swim might try the duathlon, which is running, followed by cycling, followed by running again. The closest Ironman competition is held in Frankfurt (www.ironman.de), but the Deutsche Triathlon Union (www.dtu-info.de) stages plenty of shorter triathlon events in Berlin.