Running related overuse injury (RROI) affects a significant proportion of runners annually. To date, only running mileage has been considered when quantifying the amount of loading that may elicit tissue micro-damage and injury, while the loading that occurs from activities of daily living and non-running physical activity has been ignored. By ignoring non-running physical activity (PA), we may be severely underestimating the amount of loading that leads to RROI.
PURPOSE: To determine the role of daily non-running PA on the risk of RROI development among recreational and competitive runners.
METHODS: As part of a larger prospective running injury pilot study, 50 recreational and competitive male and female runners will be enrolled and complete questionnaires regarding running history, injury history, and all forms of non-running daily PA. Participants will receive a FitBit Charge activity monitor to track PA for 24 hrs/day over 12 months. To date, questionnaires and a typical running gait analysis had been completed by 21 participants (9 male, 12 female; 27.5±6.3 years; BMI = 22.6±2.0 kg/m^2).
RESULTS: Participants had mean±SD running experience of 8.6±5.6 years and run 24.1±15.2 mi/wk. Among n = 21 participants, RROI occurred within the past year in n = 4, within the past two years in n = 11, and in their lifetime in n = 16. Current mi/wk was 54% greater in those that had sustained a RROI in their lifetime compared with those that had not (No RROI = 15.3±4.5 mi/wk; Yes RROI 26.9±16.4 mi/wk, P=0.02). Total PA was not different between those who had and had not sustained a RROI in their lifetime or in the past 1-2 years (P>0.05). Non-running PA was greater in those that did not sustain a RROI in each time period, but the differences were not significant with this initial sample size (No RROI vs Yes RROI: lifetime 11.8±8.3 vs 7.1±7.2 hrs/wk, P>0.05; 1 yr: 8.7±8.2 vs 6.1±3.9 hrs/wk, P>0.05; 2 yr: 9.2±8.6 vs 7.3±6.8 hrs/wk, P>0.05).
CONCLUSIONS: Results from the first 21 participants enrolled in this study support previous reports that running mi/wk may increase RROI risk. Given that total PA was the same between injured and non-injured runners in this sample, more hrs/wk spent in non-running PA vs running PA may reduce RROI risk. Continuous monitoring of PA collected in this 12 month study will provide evidence to support or reject this hypothesis.