Abstract
OBJECTIVES: To investigate the association between training-related characteristics and running-related injury using a new conceptual model for running-related injury generation, focusing on the synergy between training load and previous injuries, short-term running experience or body mass index (> or <25kgm(-2)).
DESIGN: Prospective cohort study with a 9-month follow-up.
METHODS: The data of two previous studies using the same methodology were revisited. Recreational runners (n=517) reported information about running training characteristics (weekly distance, frequency, speed), other sport participation and injuries on a dedicated internet platform. Weekly volume (dichotomized into <2h and ≥2h) and session frequency (dichotomized into <2 and ≥2) were the main exposures because they were considered necessary causes for running-related injury. Non-training-related characteristics were included in Cox regression analyses as effect-measure modifiers. Hazard ratio was the measure of association. The size of effect-measure modification was calculated as the relative excess risk due to interaction.
RESULTS: One hundred sixty-seven runners reported a running-related injury. Crude analyses revealed that weekly volume <2h (hazard ratio=3.29; 95% confidence intervals=2.27; 4.79) and weekly session frequency <2 (hazard ratio=2.41; 95% confidence intervals=1.71; 3.42) were associated with increased injury rate. Previous injury was identified as an effect-measure modifier on weekly volume (relative excess risk due to interaction=4.69; 95% confidence intervals=1.42; 7.95; p=0.005) and session frequency (relative excess risk due to interaction=2.44; 95% confidence intervals=0.48; 4.39; p=0.015). A negative synergy was found between body mass index and weekly volume (relative excess risk due to interaction=-2.88; 95% confidence intervals=-5.10; -0.66; p=0.018).
CONCLUSIONS: The effect of a runner's training load on running-related injury is influenced by body mass index and previous injury. These results show the importance to distinguish between confounding and effect-measure modification in running-related injury research.
Originalsprog | Engelsk |
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Tidsskrift | Journal of Science and Medicine in Sport |
Vol/bind | 18 |
Udgave nummer | 5 |
Sider (fra-til) | 523-528 |
Antal sider | 6 |
ISSN | 1440-2440 |
DOI | |
Status | Udgivet - 2015 |