BackgroundThe sport of Enduro is the newest Union Cycliste Internationale (UCI) sanctioned discipline in mountain biking and there has been a surge in its popularity and participation. Although there are a number of studies reporting mountain biking injury the study methods vary widely, there are few at elite level, and there are none currently detailing injuries at elite level Enduro mountain biking.ObjectiveTo determine the rate, severity and nature of rider injury during racing and official training at the Enduro World Series (EWS).Design2-season prospective epidemiology study (2017 & 2018).SettingMale and female riders competing in the EWS.Patients (or Participants)2,010 (90.3% male) under-21, senior and masters riders from 46 countries, during 10 race events.Interventions (or Assessment of Risk Factors)Rider injury during EWS Enduro mountain biking.Main Outcome MeasurementsInjury prevalence.ResultsOverall 8.9% of riders were injured during the two EWS seasons (9.35 injuries per 100 riders) with on average 12.3 days time-loss per injury. Female rider injury prevalence was higher, but severity lower compared with male riders (11.3%, 6.4 days; 8.7%, 13.2 days, respectively). Two-thirds (64%) of injuries occurred during racing, with 31.4% of injuries reported in inexperienced (1-race) riders. The shoulder/clavicle (13.3% of all injuries) followed by the hand (9.0%) and head (9.0%) were the most common affected anatomical locations, with concussion injury most frequent (7.2% of all injuries) and shoulder/clavicle fracture causing the greatest burden (442 total days). Of those displaying concussion symptoms 29% continued racing, of those diagnosed with concussion 43% reported no time-loss (i.e. time off) post-race.ConclusionsThe overall rate and severity of rider injury during EWS race events was low, but targeted injury prevention strategies, around shoulder injury pre- and rehabilitation, concussion education, and new/inexperienced rider qualification criteria may help to reduce the rate, severity and overall burden of some injuries.