This was how triathlon was introduced

Triathlon is defined as a three-part sports discipline comprising swimming, cycling and running. The 3 sports are contested as a continuous event without a rest. The triathlon can be an individual or team event over varying distances.

Triathlon history dates back to the early 1970s and originated with the San Diego Track Club.  The triathlon was designed to be an alternative to hard track training. The first triathlon event was held on September 25th 1974. Don Shanahan and Jack Johnstone are pioneers in the history of the triathlon. The San Diego Track Club sponsored the event. The triathlon then comprised a 10km run, 8km cycle and 500 meter swim . In 1989, the sport was awarded Olympic status and featured for the first time at the 2000 Sydney Olympics in Australia. Since then, the sport has grown in popularity. In fact, no other sport achieved Olympic status in such a short time. Over the next decade, triathlon grew by leaps and bounds and soon gained recognition worldwide.

 In 1989, the International Triathlon Union (ITU) was founded in Avignon, France, and the first official world championships were held. The official distance for triathlon was set at a 1500 meter swim, a 40km cycle and a 10km run - taken from existing events in each discipline already on the Olympic programme. This standard distance is used for the ITU World Cup series and was also featured at the Sydney Olympic Games.