Low Energy Availability, Bone Mineral Density, and Menstrual Health in Competitive Nordic Athletes: The NALEA Study

Background: Low energy availability (LEA) can adversely affect bone health, menstrual function, and performance in endurance athletes, but data in adolescent and young adult Canadian Nordic skiers and biathletes are limited. Objective: To examine indicators of LEA in competitive Nordic athletes by assessing bone mineral density (BMD), LEA risk scores, menstrual health, menstrual cycle knowledge, and ovulation status. Methods: In this cross-sectional study, twenty-one competitive Nordic athletes (13 female, 8 male; 18 cross-country skiers, 3 biathletes; age 16–23 years) completed questionnaires including the LEAF-Q/LEAM-Q, a menstrual cycle knowledge survey, and a menstrual health survey. Participants were then invited for dual‑energy X‑ray absorptiometry (DXA) to assess areal BMD, and female athletes with recent menstrual cycles were offered a home kit for urinary ovulation testing to detect the luteinizing hormone (LH) surge. Results: Male athletes had higher areal BMD than females (p 0.039), but mean Z-scores in both sexes were generally above age- and sex-matched normative values. Three of 13 female participants were classified as at risk for LEA based on LEAF-Q scores, whereas male LEAM-Q scores were reported descriptively. Female athletes scored higher on menstrual cycle knowledge than males (p 0.001) and menstrual survey data indicated predominantly eumenorrheic patterns with some exercise-related menstrual changes. Ovulation testing confirmed an LH surge in a subset of eligible female athletes, suggesting preserved ovulatory function in most who completed testing. Conclusion: In this cohort of competitive Nordic athletes, bone health was generally favourable, and LEA risk appeared low, yet the presence of menstrual symptoms and gaps in menstrual health knowledge highlight the need for ongoing education, screening, and monitoring to support long-term athlete health.