Run Clever – No difference in risk of injury when comparing progression in running volume and running intensity in recreational runners: A randomised trial

BACKGROUND/AIM: The Run Clever trial investigated if there was a difference in injury occurrence across two running schedules, focusing on progression in volume of running intensity (Sch-I) or in total running volume (Sch-V). It was hypothesised that 15% more runners with a focus on progression in volume of running intensity would sustain an injury compared with runners with a focus on progression in total running volume. METHODS: Healthy recreational runners were included and randomly allocated to Sch-I or Sch-V. In the first eight weeks of the 24-week follow-up, all participants (n=839) followed the same running schedule (preconditioning). Participants (n=447) not censored during the first eight weeks entered the 16-week training period with a focus on either progression in intensity (Sch-I) or volume (Sch-V). A global positioning system collected all data on running. During running, all participants received real-time, individualised feedback on running intensity and running volume. The primary outcome was running-related injury (RRI). RESULTS: After preconditioning a total of 80 runners sustained an RRI (Sch-I n=36/Sch-V n=44). The cumulative incidence proportion (CIP) in Sch-V (reference group) were CIP(2 weeks) 4.6%; CIP(4 weeks) 8.2%; CIP(8 weeks) 13.2%; CIP(16 weeks) 28.0%. The risk differences (RD) and 95% CI between the two schedules were RD(2 weeks)=2.9%(−5.7% to 11.6%); RD(4 weeks)=1.8%(−9.1% to 12.8%); RD(8 weeks)=−4.7%(−17.5% to 8.1%); RD(16 weeks)=−14.0% (−36.9% to 8.9%). CONCLUSION: A similar proportion of runners sustained injuries in the two running schedules.