To evaluate whether a high body mass index (BMI) predisposes marathon/half-marathon participants to lower extremity injuries.
Consenting adult participants at the 2008 National Marathon to Fight Breast Cancer were enrolled in this observational study. The primary outcome measure was prevalence of self-reported lower extremity injury, during both training and race participation, with respect to BMI.
There were 194 subjects with complete data: 139 females (72%) and 55 males. Forty-six percent of females and 51% of males ran the full marathon (P = .63). Median BMI was 23.7 kg/m2 for females and 26.2 kg/m2 for males (P = .001). Eleven (24%) females in BMI tertile 1 (T1) suffered a training injury, while 9 (18%) from T2 and 4 (9%) from T3 suffered injuries (P = .072; OR 0.89; 95% CI 0.78 to 1.01). Twenty-six (19%) females suffered an injury during the race. Females in T1 were more likely to suffer a race-related injury (P = .038; OR 0.87; 95% CI 0.77 to 0.99). Females were 13% less likely to suffer a race-related injury with each 1-unit increase in BMI. Rates of injury did not differ by BMI tertile in males.
A high BMI did not impart an increased risk of lower extremity injury during training or race participation.