Obstacle course racing involves large scale mass participation events held mostly outdoors across multiple distances, ranging from 100 metres to ultra marathon distances. The terrain is usually off-road or multi-terrain and involves technical footwork over mud, hills and rough terrain. Within the race are a variety of whole-body obstacles including but not limited to: walls, rope climbs, monkey bars, rigs, carries, and swims.

There are many races, championships, series, brands, teams and training centres across the UK, and indeed the world. When an athlete is unable to complete an obstacle there may be different, often physical, penalties attached that must be completed before finishing the race. Competitive races are chip timed and the winner is the athlete/team who completes the course and any penalties as fast as possible. There are team/relay events and events of different distances (sprint, short-course, classic course, ultra-distance).