Adventure racing is a combination of two or more disciplines, including orienteering and navigation, cross-country running, mountain biking, paddling and climbing and related rope skills. An expedition event can span ten days or more while sprints can be completed in a matter of hours. Typically there is no "dark period" during races, regardless of their length - the choice when (and if) to rest is left to the competitors.
Adventure racing is classically a co-ed team sport. Nonetheless, many races now permit "teams" of 1 to 5 persons, single-sex or co-ed, and sometimes include age-based categories.