Sex Differences in Stress Fracture Incidence and Risk Factors in Athletes: A Narrative Review

Background. Stress fractures are a prevalent overuse injury in athletes, with female athletes consistently reporting higher incidence rates than males. This disparity is driven by an interplay of anatomical, hormonal, biomechanical, and training-related factors. Aim. This narrative review aims to synthesise the current evidence on sex differences in stress fracture incidence and to identify the key risk factors underlying this disparity. Methods. A narrative literature review was conducted using PubMed, Web of Science, and Scopus. Studies published between 2015 and 2026, with an emphasis on 2020–2026, were included. Peer-reviewed original research articles, systematic reviews, and meta-analyses addressing stress fractures in athletes with sex-stratified data were considered. Results. Female athletes exhibit higher rates of tibial, metatarsal, and tarsal stress fractures compared to males. Contributing factors include smaller bone cross-sectional geometry, lower cortical bone density, and distinct trabecular microarchitecture. Hormonal disruptions associated with the Female Athlete Triad and Relative Energy Deficiency in Sport further impair bone metabolism in women. Sport-specific loading, early specialisation, low body mass index, and menstrual irregularities compound this risk. Conclusions. The excess stress fracture risk in female athletes is multifactorial. Effective prevention requires sex-specific screening for energy deficiency, menstrual health monitoring, and individualised training load management.