Duathlons are most similar to triathlons, with the key difference being the replacement of the swimming leg with a second run.

The word duathlon is also used for some events which comprise running or walking and cycling, but not in three stages, such as the annual Highland Cross in Scotland.

[3] In this variation, the cycling and running segments need to be undertaken simultaneously by a team consisting of a predetermined number of individuals.

The challenge is to rotate the task of running at an optimum rate such that the time from start to destination is minimized.

In its ninth year, London Duathlon took place on Sunday 14 September 2014 and offered athletes of all abilities the chance to race through the stunning surroundings of Richmond Park while on closed roads.

The longest continually running duathlon series is still organized by the NY Triathlon Club[8] in and around New York City, US.

The Dirty Du off-road duathlon series, held in Texas, was made famous by Lance Armstrong, who won it in 2003.