triathlon

American  

[trahy-ath-luhn] / traɪˈæθ lən /

noun

1. an athletic contest comprising three consecutive events, usually swimming, bicycling, and distance running.

2. a women's track-and-field competition comprising the 100-meter dash, high jump, and shot put.

3. British. a competition comprising fly-casting, horseback-riding, and trapshooting events.

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triathlon British  

/ traɪˈæθlɒn /

noun

1. an athletic contest in which each athlete competes in three different events: swimming, cycling, and running

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Usage

What is a triathlon? The word triathlon most commonly refers to an athletic competition in which athletes compete in a race that involves swimming, cycling, and distance running. The traditional triathlon begins with a 1. 5-kilometer open-water swim, followed by a 40-kilometer bike race, and finishes with a 10-kilometer run. This triathlon format is an event in the Summer Olympic Games. Triathlons sometimes feature different formats. A longer version often branded as an Ironman triathlon consists of a 2. 4-mile (3. 9-km) swim, a 112-mile (180. 2-km) bike, and marathon-length run of 26. 2 miles (42. 2 km). In 2021, the Olympics introduced a shorter, relay version of the triathlon featuring teams of two men and two women. Each member of the team must complete a triathlon consisting of a 300-meter swim, an 8-kilometer bike ride, and a 2-kilometer run. The name triathlon is also applied to other three-part athletic competitions that are not a race but are instead score-based (the three events are not held directly one after another as part of a race like they are in the swim-cycle-run version of a triathlon). The track-and-field version of a triathlon consists of the 100-meter dash, high jump, and shot put. In the U. K., the word triathlon sometimes refers to a three-part skill competition involving fly-casting, horseback-riding, and trapshooting. A triathlon is sometimes informally called a tri for short. Athletes who participate in a triathlon can be called triathletes. Example: The triathlon is nearing its third stage now as the triathletes transition from the cycling portion to the run.

Other Word Forms

• triathlete noun

Etymology

Origin of triathlon

First recorded in 1970–75; tri- + (dec)athlon

Explanation

The triathlon is a sport that includes three events, usually swimming, bicycling, and running. Athletes compete in triathlon at the summer Olympics every four years. If you're an accomplished cyclist and runner, all you need to do is work on your swimming skills to enter a triathlon. You also need endurance; triathletes typically swim for 1500 meters, ride a bike for 40 kilometers, and then run a 10K. The person who completes all three sections of the triathlon in the shortest amount of time is the winner. This word was coined in 1970 from the prefix tri-, or "three," and the Greek athlon, "contest."

Example Sentences

On day one, July 15, the most women's finals ever held on one day will be contested, starting with women's triathlon with a spotlight on the women's 100 meters.

From Barron's • Nov. 12, 2025

“If they’re too aggressive early, they’re basically burning matches,” said Andrew Yoder, a high performance triathlon coach who preaches the benefits of uphill running.

From The Wall Street Journal • Nov. 1, 2025

She’s already dreaming of her next triathlon, perhaps the Alpe d’Huez in the French Alps.

From Slate • Sep. 9, 2025

An athlete has died after competing in the Ironman 70.3 Swansea triathlon event last weekend, organisers have said.

From BBC • Jul. 16, 2025

He got a list of every high school and university in each river town, and cross-referenced everyone who had been on a swim team for the past twenty years or had registered for a triathlon.

From "Scythe" by Neal Shusterman