Enduro is a form of Mountain bike racing in which there is a number of timed downhill sections of trail, and a number of uphill transfer stages, which are not timed, but might have time limits to complete. It is a stage-race format where the winner is the rider who accumulates the lowest combined time from the various timed sections. Mountain bike enduro competitions typically take place over the course of 1 or 2 days, however, week-long enduro competitions do also exist. A typical one-day enduro race consists of 3 to 5 timed "special" stages which take place on technically demanding, generally descending terrain. These special stages are linked by predominantly ascending "liaison" stages. Although a rider's specific performance on the physically demanding liaison stages does not affect his or her result, the liaisons are often associated with a time cut-off (i.e. a latest permitted arrival at the summit of the next special stage). The sport has taken root mostly in the Northwest of United States, and in Europe, locations known for their miles of winding single-track trails alongside old growth forest and bubbling creeks.
According to the Enduro World Series 2015 Rule Book, a minimum of four special stages is required per event, a minimum of three different courses must be used, and the results will be calculated by adding all stage times together for each rider.
Enduro differs from XC cross-country cycling racing (which historically has more emphasis on cardiovascular fitness and less emphasis on technical ability) and pure downhill cycling racing formats, which may contain little to no climbing or cross country skills.
Enduro's 'All Mountain' discipline therefore favours riders with a breadth of skill, on multi discipline cycles; lightweight XC bikes may lack sufficient suspension travel for fast downhill control, whilst full DH bikes may not allow a rider to climb the uphill sections.
In some countries, the term Enduro racing is used as a contraction of the word endurance; it is debatable if this use is misleading in this context.