Epidemiology of Injury and Illness Among Trail Runners: A Systematic Review.

Trail running takes place on uneven, hilly terrain that differs a lot from road or track running, and this review asked what is actually known about how often trail runners get hurt or sick. The authors pulled together sixteen studies covering more than 8,600 participants, most of them looking at single-day races rather than everyday training. What they found was a huge range in reported rates, from as low as about 1.6 up to over 4,000 injuries per 1,000 hours of running, and a similarly wide range for illness.

The most common injuries involved the feet, knees, lower legs, thighs, and ankles, with skin cuts, scrapes, and blisters topping the list, alongside muscle strains, cramping, and ligament sprains. Stomach and gut problems, along with metabolic and heart-related issues, were the most frequently reported illnesses. The wide variation in numbers and the near-total focus on race days rather than training make it hard to draw firm conclusions about how often problems really occur.

If you run trails, you might wonder how common injuries and illness really are compared with road running. This review gathered sixteen studies with over 8,600 trail runners to try to answer that, but the results turned out to be quite scattered.

Reported injury rates ranged enormously, from very low to very high, depending on the study, and the same was true for illness. That variation itself is a useful finding because it tells us the numbers aren't yet settled or consistent. What did come through clearly was which body parts and problems showed up most.

Feet, knees, lower legs, thighs, and ankles were the most frequently injured areas, with skin cuts, scrapes, and blisters being the most common issues, followed by muscle strains, cramping, and ligament sprains. On the illness side, stomach and digestive troubles, like nausea and vomiting, along with metabolic and heart-related symptoms, stood out most. A key limitation is that almost all of this comes from single race days, not regular training, so we don't have a clear picture of how often injuries and illness happen during everyday trail running practice.

This is a summary of research, not medical advice. Talk to your own healthcare provider about anything affecting your care.

This systematic review synthesised sixteen studies (n=8,644) examining injury and illness epidemiology in trail runners, with methodological quality assessed using an adapted Downs and Black tool. Thirteen studies focused on race-related events and only three addressed training-related injury, which is an important gap given that races represent a small fraction of a trail runner's overall exposure.

Reported incidence ranged from 1.6 to 4,285.0 injuries per 1,000 hours of running and 65.0 to 6,676.6 illnesses per 1,000 hours, an extremely wide spread reflecting differences in study design, race distance, terrain, and definitions used across studies rather than a single reliable rate. Anatomically, the foot was the most commonly affected site, followed by the knee, lower leg, thigh, and ankle. Skin lacerations and abrasions were the leading injury diagnosis, followed by blisters, muscle strains, cramping, and ligament sprains.

Gastrointestinal symptoms, particularly nausea and vomiting linked to gut distress and dehydration, were the most frequent illness category, followed by metabolic and cardiovascular issues. Given the heterogeneity in outcome definitions, the race-day skew, and variable study quality, this body of evidence supports descriptive characterisation of injury and illness patterns but does not yet allow confident quantification of true incidence or comparison across race formats or training contexts.