Duathlon is an athletic event that consists of a running leg, followed by a cycling leg and then another running leg in a format similar to triathlons. The International Triathlon Union governs the sport internationally.

A triathlon is an endurance multisport race consisting of swimming, cycling, and running over various distances. Triathletes compete for fastest overall completion time, racing each segment sequentially with the time transitioning between the disciplines included. The word is of Greek origin, from τρεῖς or treis (three) and ἆθλος or athlos (competition).