Background The INSPIRE trial examined in 2017 the effect of an online injury prevention program on the number of running-related injuries (RRI). Although this program showed no effect on the number of injuries, new insights from this study were used to design an enhanced prevention program.

Objective To examine the effectiveness of an online injury prevention program on the number of RRIs in recreational runners.

Design Randomized controlled trial.

Setting This study includes analyses of a randomized controlled trial on RRI prevention in recreational runners registered for a Dutch running event (distances 10–42.195 km).

Participants 4105 adult, recreational runners who registered at least two months before the running event and did not participate in the INSPIRE trial.

Interventions Participants that were randomized into the intervention group were given access to the online ‘10 steps 2 outrun injuries’ prevention program, which included 10 steps with advice to prevent RRIs. Participants received three follow-up questionnaires: one month and one week before the registered running event and one month after the running event.

Main Outcome Measurements The number of new RRIs in the intervention and control group during follow-up. Secondary outcome measures included the injury proportions in participants per injury location and in participants with an RRI in the 12 months before baseline.

Results During follow-up, 35.5% (95% CI 33.5;37.6) of the participants in the intervention group sustained a new RRI compared to 35.4% (95% CI 33.3;37.5) of the participants in the control group, with no differences between groups (OR 1.03; 95% CI 0.90;1.17). No significant differences in injury proportions were found in participants per injury location and in participants with an RRI in the 12 months before baseline.

Conclusions An enhanced online injury prevention program including 10 steps to outrun injuries had no effect on the number of RRIs in recreational runners.