Triathlon as a sport is still relatively new, having its rootin France in the 1920s. Competitors particiated in a race called "Les trios sports" - translated literally to "Three Sports" - which consisted of crossing the channel Marne, a 12k bike ride and 3K run. In 1934, the race was consisted of crossing the channel, a 10K bike ride and a 1200 meter run.
Triathlons in America can be traced to Southern California in the 1970s. The first Mission Bay Triathlons was held on September 25, 1974 in San Diego. This is the date that most hold to be the offical "birthday" of the modern triathlon. There were 46 people that showed up to compete in the multisports event consisting of a 500-yard swim, a 5-mile bike ride, and a 6-mile run.
As the sports started to catch on more and more, the beginnings of the most famous triathlons in the world began to unfold in Hawaii.Three seperates events - the Waikiki Rough Water Swim (2.4 miles), The Oahu Bike Race (122 miles), and The Honolulu Marathon (26.2 miles) - were combined in 1978 to form the Hawaii Ironman Triathlon. Of the 15 competitors who started the race, only 12 of them rossed the finised line. By the early 1982, ABC's Wide World of Sports was broadcasting the Hawaii Ironman and nearly 600 people entered the race. That number ballooned to nearly 300 in 2006.
As trianthlon continue to grow in popularity, offical rules committees began to form. Today, there are multiple governing bodies for the sport of trianthlons, each sanctioning and supporting diffrent length races. The most prominent of which are USA Triathlon (USAT) , The World Triathlon , and the World Traithlon Corporation (WTC), which licenses the ironman series of races.
USA Triathlon (USAT) is the national govering body for triathlon, duathlon, aquathlon and winter triathlon, of which it sanctions more than 2000 races each year. The USAT formed in 1982 when the U.S. Triathlon Association and the American Triathlon Association merged. Original membership was only about 1500. In just 25 years, membership has grown to more than 100,000 making it the largest multisport organization in the world.
More information about the USAT can be found here.
World Triathlon or formerly known as The International Triathlon Union (ITU) was founded in 1989 in Avignon,France, the site of the first offical world championships. The primary race of the ITU is the Olympic distance race. The World Triathlon sanctions and organized a World Cup series of these races every year, culminating in an annual World Championship for elite pro-triathletes, junior pro-triathletes and amatuer athletes in 5-year age-groups.
More information about the ITU can be found here.
The World Triathlon Corporation (WTC) was founded in 1990 and organizes, licenses, and promotes the Ironman Triathlon Series, culminating each year with the Hawaii Ironman Triathlon World Championships. Althugh the Ironman races are not recognized by the ITU as official world championships, the Hawaii Ironman race is considered by most to be the most prestigious event in the world.