Off-road triathlon
Off-road triathlon is a form of triathlon, or three-stage race, consisting of a swim stage, mountain-biking stage, and a trail-running stage.
Off-road triathlons are distinguished from conventional triathlons in that the terrain for the cycling and running stages are generally unpaved, rough, and very steep and hilly. They require different techniques than conventional triathlon races, and in particular the athletes employ mountain bikes rather than road bikes.
An off-road triathlon requires a higher degree of technical biking skill, as opposed to the high speed and endurance demands of road biking in a road triathlon. Distances for the bike portion of an off-road are much less relevant than for a road triathlon. An off-road bike course may have several severe climbs and descents. It may also have a high degree of technicality, meaning the number, pitch and sharpness of turns through trees, rocks, logs, streams and other obstacles on the bike trail. Because the vertical climbs and technical demands of an off-road course greatly reduce a biker's speed, and because the amount of climbing and technicality vary greatly from one off-road course to another, estimating times for an off-road bike course merely by distance is not reliable.
Off-road triathlon swim courses are normally similar to those of road triathlons. Each type of triathlon usually requires competitors to swim a minimum of 800 meters and typically 1500 meters in a lake, river or ocean.
Off-road run courses often follow part of the off-road bike course, and so often require trail running up and down hills or mountain sides, through forests, streams, riverbeds and other natural and occasionally man-made obstacles. The run distance is at least 5 kilometers and normally 10 kilometers. Again, as in off-road biking, predicting a finish time purely based on distance will not be accurate, due to the climbing and trail turns and obstacles preventing a runner from reaching speeds usually achieved on the road.
The XTERRA is the best-known series and championship of off-road triathlons, although others exist.