In the context of motorcycle sports, an enduro race is an outdoor motorcycle race that is designed not only to test a rider's speed but also his or her physical and mental endurance, which is where the event's name derives. Races often span miles and last for hours, with participants expected to negotiate rugged outdoor conditions.
Enduro races almost always take place at an outdoor course, and while specific regional governing bodies may have specific rules that determine how a course is set up, these are generally very long courses that are required to run their majority in off-road conditions. One of enduro's chief unique characteristics is its use of time as a constraint on racers. Rather than racing against one another to see who finishes the course first, these racers are trying to beat the clock, which has a set time that is determined before the race begins. Riders in these races must focus not only on running the course and being efficient with speed but also on obstacles such as mud puddles or fallen logs and hazards such as hanging tree branches. Enduro races are popular in both Europe and the United States.