Trail running

This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. Find sources: "Trail running" – news · newspapers · books · scholar · JSTOR (December 2018) (Learn how and when to remove this message)

Trail running is a type of running that takes place on outdoor trails, often in mountainous terrain, and often includes significant ascents and descents. Trail running is overseen by the International Trail Running Association (ITRA) and includes longer races.^[1][2]

It is similar to both mountain and fell running (also known as hill running). Unlike road running and track running, it generally takes place on outdoor trails, often in mountainous terrain, and often includes significant ascents and descents.^[1] It is difficult to definitively distinguish trail running from cross country running. In general, however, cross country running is a discipline governned by the IAAF, which is typically raced over shorter distances, while trail running is overseen by ITRA and includes longer races.

The number of organized trail races grew by 1,000% from 2008 to 2018, from 160 to more than 1,800 globally.^[3] Runners often cite less impact stress compared to road running, as well as the landscape and non-urban environment, as primary reasons for preferring trail running.^[4] This move to nature is also reflected in a large increase in competitors in non-traditional/off-road triathlons and adventure racing in the 2010s.^[5]