Early triathlons were held as off-beat training exercises for runners. The first known swim/bike/run triathlons were held at San Diego’s (Calif.) Mission Bay in 1974. Organized by members of the San Diego Track Club, the events were held on summer evenings and were intended as no more than light-hearted breaks in the normal grind of training for marathons and 10Ks. One athlete who raced at the first Mission Bay Triathlon, John Collins, was very influential in the further development of the sport. Collins, a U.S. Naval Officer, took the triathlon concept to Hawaii and used it several years later to combine three of Oahu’s endurance events – the Waikiki Rough Water Swim, the Around-Oahu Bike Ride and the Honolulu Marathon – into one race: the Ironman.
Only 12 men completed the first race held in January of 1978. In 1979, 13 men and one woman crossed the finish line. But a Sports Illustrated article by Barry McDermott in May 1979 increased the 1980 field into the hundreds and brought ABC’s Wide World of Sports to Hawaii for the first of an unbroken string of annual network broadcasts. In 1982, the last year no qualifying was needed to compete at Ironman, the dramatic footage of Julie Moss crawling on her hands and knees to a second-place finish at Ironman, triggered an explosion of interest. The same year also witnessed the birth of Triathlon Magazine, the sport’s first national publication; the founding of the U.S. Triathlon Association (later named USA Triathlon), triathlon’s national governing body; and the U.S. triathlon Series, the first national racing series.
The decade that saw phenomenal growth in triathlon, the 1980s, ended with a step toward the future. In 1989, after several failed attempts, triathlon formed an international governing body. Twenty-five nations were represented at the founding congress of the International Triathlon Union in April in Avignon, France. The focus of the International Triathlon Union (ITU) was to gain acceptance by the International Olympic Committee and have triathlon accepted on the Olympic program. The first step in that process would be to create a triathlon world championship. The race took place four months later in Avignon with Mark Allen of the United States and Erin Baker of New Zealand winning the inaugural world championship.
The Ironman World Championship in Hawaii may be triathlon’s most recognizable event, but the international distance is the sport’s most popular. The 1.5K swim, 40K bike, and 10K run is triathlon’s international standard and the format used at the triathlon world championship and eventually the Olympics. The 1980s also saw the development of the "sprint distance" triathlon, which is about half the distance of an international distance race.
In 1991, the IOC recognized the ITU as the sole governing body for the sport of triathlon at its 97th session in Birmingham, England. In 1993 the Pan American Games approved triathlon for competition at the 1995 Pan Am Games in Mar del Plata, Argentina. The first Goodwill Games Triathlon was held in St. Petersburg, Russia on July 23, 1994. Then in September of 1994, triathlon was named to the Olympic program as a medal sport at the 2000 Olympic Games in Sydney, Australia.
The first Olympic triathlons were held Sept. 16-17, 2000 in Sydney, Australia. Switzerland's Brigitte McMahon won the women's race and Canada's Simon Whitfield won the men's race.
The United States won its first Olympic triathlon medal on August 25, 2004, when Susan Williams of Littleton, Colo., placed third in the women’s event in Athens, Greece. Kate Allen of Austria won the women’s race and Hamish Carter of New Zealand won the men’s race the next day.