τρίαθλον

Triathlon combines Greek tri (three) and athlon (contest). No ancient Greek competition combined swimming, cycling, and running — bicycles did not exist in antiquity. The word was manufactured from classical parts to lend dignity to what began as a casual dare. The San Diego Track Club organized the first modern triathlon on September 25, 1974, at Mission Bay. Forty-six people showed up.

The format crystallized in Hawaii. In 1978, Navy Commander John Collins proposed combining Oahu's three toughest endurance events: the Waikiki Roughwater Swim (2.4 miles), the Around-Oahu Bike Race (112 miles), and the Honolulu Marathon (26.2 miles). Whoever finished first, Collins argued, would be an Iron Man. Fifteen people entered. Twelve finished. Gordon Haller won in 11 hours, 46 minutes. The Ironman was born, and the triathlon had its defining format.

The sport grew rapidly through the 1980s and 1990s. The International Triathlon Union was founded in 1989. The Olympic triathlon — a shorter distance of 1.5 km swim, 40 km bike, and 10 km run — debuted at the 2000 Sydney Games. The Olympic version took about two hours. The Ironman took twelve. Same word, same three sports, wildly different experiences.

The Greek suffix gives the sport classical authority it did not earn historically. There was no triathletes at Olympia. But the word works because the Greek root athlon means not just 'contest' but 'struggle,' and three consecutive endurance sports in a single race is exactly that.