Sex-Differences in Characteristics and Factors Associated With New Running-Related Injuries Among Recreational Runners

Previous findings of sex-differences in type, location, consequences, and risk factors of running-related injuries (RRIs) are contradictory. We aim to clarify these potential sex-differences. This cohort study analyzed prospective RRIs among recreational runners participating in running events (5-42 km) by combining data of two RCTs, including all intervention arms. Participants received a baseline questionnaire at registration and three follow-up questionnaires (before and up to 1 month after the event) detailing runners characteristics, injury characteristics (location, type [muscle and tendon], joint injury, etc.), and consequences (medication use, pain scores [0-10]). A predetermined injury definition was used to register RRIs. Data analysis was performed using descriptive statistics and univariate and multivariable logistic regression analysis of risk factors for a new RRI (demographics, training characteristics, event distance, and RRI-history), using separate models per sex. We analyzed 6428 participants with an average follow-up time of 4.8 months, 82% finished at least one follow-up questionnaire. During follow-up, 2133 (33%) participants (33% men, 34% women) suffered one or more RRIs. We found no sex-differences in injury location and type of injury. Men used less medication (13% vs. 15%, p = 0.01) and had lower pain scores while running (4.2 [SD2.9] vs. 4.5 [SD 2.8], p = 0.04) compared to women. A history of RRIs was associated with a new RRI in both men (OR 1.9 [95% CI: 1.6-2.2]) and women (OR 1.7 [95% CI: 1.4-2.0]). No relevant sex-differences were found between middle-aged runners. Our findings do not support accounting for sex-specific factors, specifically with regard to training characteristics, injury history, or injury consequences, in the development of personalized RRI risk reduction.Trial Registration: The INSPIRE trial (NTR5998) and SPRINT study (NL7694) were prospectively registered in the Dutch Trial Register