A triathlon is a multiple-stage competition involving the completion of three continuous and sequential endurance disciplines. While many variations of the sport exist, triathlon, in its most popular form, involves swimming, cycling, and running in immediate succession over various distances. Triathletes compete for fastest overall course completion time, including timed "transitions" between the individual swim, cycle, and run components. The word "triathlon" is of Greek origin from t?e?? or treis ("three") and ????? or athlos ("contest"). Triathlon races vary in distance. According to the International Triathlon Union, and USA Triathlon, the main international race distances are: Sprint Distance; 750-meter (0.47-mile) swim, 20-kilometer (12-mile) bike, 5-kilometer (3.1-mile) run Intermediate (or Standard) distance; commonly referred to as the "Olympic distance": 1.5-kilometer (0.93-mile) swim, 40-kilometer (25-mile) bike, 10-kilometer (6.2-mile) run Long Course;1.9-kilometer (1.2-mile) swim, 90-kilometer (56-mile) bike, and a 21.1-kilometer (13.1-mile) run (half marathon) ITU Long Distance;4-kilometer (2.5-mile) swim, 120-kilometer (75-mile) bike, and a 30-kilometer (19-mile) run Ultra Distance; commonly referred to as 140.6 (total distance in miles, equivalent to 226.2 km) or the 'Ironman'; 3.8-kilometer (2.4-mile) swim, 180.2-kilometer (112.0-mile) bike, and a 42.2-kilometer (26.2-mile) run (full marathon) The most recognized branded Ultra Distance is the Ironman triathlon. A transition area is set up where the athletes change gear for different segments of the race. This is where the switches from swimming to cycling and cycling to running occur. These areas are used to store bicycles, performance apparel, and any other accessories needed for the next stage of the race. The transition from swim and bike is referred to as T1 and that between the bike and run is referred to as T2. The athlete's overall time for the race includes time spent in T1 and T2. Transitions areas vary in size depending on the number of participants expected. In addition, these areas provide a social headquarters before the race. The nature of the sport focuses on persistent and often periodized training in each of the three disciplines, as well as combination workouts and general strength conditioning.
Triathlon is considered by some to have its beginnings in 1920s France. According to triathlon historian and author Scott Tinley (and others), the origin of triathlon is attributed to a race during the 1920s–1930s that was called variously "Les trois sports", "La Course des Débrouillards", and "La course des Touche à Tout." This race is held every year in France near Joinville-le-Pont, in Meulan and Poissy. An earlier tri-sport event in 1902 featured running, cycling, and canoeing. There are documented tri-sport events featuring running, swimming, & cycling (not necessarily in that order) in 1920, 1921, 1945, and the 1960s. In 1920, the French newspaper L´Auto reported on a competition called "Les Trois Sports" with a 3 km (1.9 mi) run, 12 km (7.5 mi) bike, and a swim across the channel Marne. Those three parts were done without any break. Another event was held in 1921 in Marseilles with the order of events bike-run-swim. French newspapers reported on a race in Marseille in 1927, and in 1934 an article about "Les Trois Sports" (the three sports) in the city of La Rochelle was written about a race with: (1) a channel crossing (c. 200 m [660 ft]), (2) a bike competition (10 km [6.2 mi]) around the harbor of La Rochelle and the parc Laleu, and (3) a run (1,200 m [3,900 ft]) in the stadium André-Barbeau.