Background

Factors associated with injuries and performance have been less studied in trail running than in road running. Our original research carried out on a large sample of trail runners had 3 aims: 1) describe the habits and health of runners 2) evaluate the causal effect of training variables, anthropometric factors, lifestyle, recovery on the incidence of injuries 3) evaluate causal effect of these parameters on performance.

MethodsWe developed a 65 questions trail-running-specific survey including 97 variables characterizing 3 dimensions. This anonymous questionnaire was distributed via social networks and the MSOChrono® mailing list between May 2019 and May 2020. We tested all potentially predictive variables with all injuries using standard frequentist tests. Then, we used causal Bayesian networks to evaluate the effect of a specific set of variables on injury probability and performance.Results

697 subjects were included (468 men). Sixteen types of injury were reported. The risk of injury was higher with weight, less interval trainings, lower weekly training volume and yearly elevation gain, lower regular passive recovery practice, lower sleeping time. The number of previous injuries didn’t affect the risk of current injury. Performance increased with training, passive recovery and sleeping, but decreased with increasing age, weight, and height.

Conclusion

The analysis of this cohort showed that some aspects of training and recovery were protective factors against injuries. There might however exist an upper limit, where some of these variables could become detrimental. More research is needed to determine this threshold.