Training for shorter ultra-trail races results in a higher injury rate, a more diverse injury profile, and more severe injuries: 2022 Mac ultra races

Abstract

Objectives: Determine and compare the epidemiology, clinical characteristics, and injury severity among race entrants training towards different ultra-trail race distances.

Design: Retrospective cross-sectional study.

Setting: The six months training period before the 2022 Mac Ultra races (46 km, 80 km, 161 km and 322 km).

Participants: Of the 245 race entrants, 162 (66% of Mac ultra-trail runners) consented to analyse their data.

Outcome measures: Injury rate (injuries per 1000 h of running), point prevalence (% of currently injured participants), injury severity (time loss), and the frequency (n, %) of injuries reported during pre-race medical screening in the six months before the race. Using inferential statistics, we compared the injury rates between the different race distance categories (46 km, 80 km, 161 km, 322 km). All tests were performed at a 5% level of significance.

Results: We reported a statistically significantly higher injury rate among 46 km study participants (3.09 injuries per 1000 h) compared to the injury rates reported among 80 km (0.68 injuries per 1000 h; p = 0.001) and 161 km (1.09 injuries per 1000 h; p = 0.028) participants. The lower limb (89%) was the most injured anatomical region, with only 46 km study participants reporting upper limb, trunk, and head injuries (11%). Muscle/tendon was the most reported injured tissue type (56%), with muscle injuries (31%) the most reported pathology type. Shorter distance ultra-trail runners reported the highest injury severity.

Conclusion: Ultra-trail runners training towards shorter ultra-trail distance races presented with a higher injury rate, more diverse injury profile, and a higher injury severity.

Keywords: Epidemiology; Injury; Trail running; Ultra-trail.