Introduction: The United States Department of Health and Human Services disseminated physical activity (PA) guidelines (PAGs) for Americans in 2008. The guidelines are based on appropriate quantities of moderate-to-vigorous aerobic PA and resistance exercise (RE) associated with decreased morbidity and mortality risk and increased health benefits. However, increases in PA levels are associated with increased risk of musculoskeletal injuries (MSIs). We related the amount and type of PA conducted on a weekly basis with the risk of MSI.
Methods: A prospective, observational study using weekly Internet tracking of moderate-to-vigorous PA and RE behaviors and MSIs in 909 community-dwelling women for up to 3 yr was conducted. The primary outcome was self-reported MSIs (total, PA related, and non-PA related) interrupting typical daily work and/or exercise behaviors for ≥ 2 d or necessitating health care provider visit.
Results: Meeting versus not meeting PAGs was associated with more MSIs during PA (HR = 1.39, 95% confidence interval [CI] = 1.05-1.85, P = 0.02) but was not associated with MSIs unrelated to PA (HR = 0.99, 95% CI = 0.75-1.29, P = 0.92) or with MSIs overall (HR = 1.15, 95% CI = 0.95-1.39, P = 0.14).
Conclusions: The results illustrate the risk of MSI with PA. MSI risk rises with increasing PA. Despite this modest increase in MSIs, the known benefits of aerobic and resistance PAs should not hinder physicians from encouraging patients to meet current PAGs for both moderate-to-vigorous exercise and RE behaviors with the intent of achieving health benefits.