Multiple Stress Fractures Higher In Female Recreational Runners At Risk Of Low Energy Availability

INTRODUCTION: Low energy availability (LEA) is the underlying factor for Relative Energy Deficiency in Sport (RED-S) which includes a facet of bone health. Stress fractures (SF) are common injuries among runners and have a high rate of recurrence. The prevalence of coexisting LEA and multiple SF in recreational runners is unknown. PURPOSE: To: 1) assess the prevalence of multiple SF and risk of LEA among recreational female runners and 2) compare characteristics frequently associated with LEA between runners with two or more SF to runners who have experienced one or fewer. METHODS: Female noncompetitive, recreational runners (running > 10 miles/week, 18-25 years old) completed an online survey that included the Disordered Eating Screening Assessment (DESA-6) and Low Energy Availability in Females Questionnaire (LEAF-Q) as well as additional questions related to body weight, food restriction, and stress fracture history. RESULTS: 458 females were divided into two groups ≤ 1 lifetime stress fractures (≤ 1 SF) (n = 309) and ≥ 2 lifetime stress fractures (≥ 2 SF) (n = 149). The prevalence of females at risk of LEA by the LEAF-Q was significantly higher in the ≥2 SF group (85%) compared to ≤1 SF group (49%) (p = 0.01). A logistic regression analysis suggested being classified as at risk for LEA (OR=1.95, p=0.03); intentionally restricting specific foods, food groups, or the amount of food consumed to lose weight (OR=2.53, p=<0.01); or currently having an eating disorder (OR = 2.39, p=<0.01) was associated with ≥2 SF. CONCLUSION: Female recreational runners with a history of ≥2 SF were more likely to be at risk of LEA, restrict food intake, and self-identify as having an eating disorder. The LEAF-Q can be used to assess LEA, which is the underlying cause of the RED-S, and may serve as an easy to administer SF risk assessment tool. Self-reported current ED and intentionally restricting food appear to be predictors for multiple SF among recreational female runners, and related questions should be included in SF risk assessment.