Bone Health in Elite Norwegian Endurance Cyclists and Runners: A Cross-Sectional Study

Abstract

What are the new findings? ► Elite road cyclists have lower bone mineral density (BMD) compared with middle-distance and long-distance elite runners, despite performing lower limb heavy resistance training. Ten of 19 cyclists were classified with low BMD. ► Low BMD was evident in male and female cyclists and affected the lumbar spine and the femoral neck. ► Type of sport was the only independent variable associated with low BMD. How might it impact on clinical practice in the near future? ► Our finding of prevalent low BMD in elite cyclists extends previous research and raises the question of whether these athletes will be at risk of osteoporosis. ► The study also raises the issue of site-specific screening for osteoporosis in this population. AbsTrACT background Athletes who compete in non-weightbearing activities such as swimming and cycling are at risk of developing low bone mineral density (BMD). Athletes in long-distance running are at risk of low BMD. Objective (1) To evaluate the bone health in Norwegian male and female national elite road cyclists and middledistance and long-distance runners, and to identify cases of low BMD. (2) To identify possible risk factors associated with low BMD. Methods Twenty-one runners (11 females and 10 males) and 19 road cyclists (7 females and 12 males) were enrolled in this cross-sectional study. Dual-energy X-ray absorptiometry measurement of BMD in total body, femoral neck and lumbar spine was measured. Participants completed a questionnaire regarding training, injuries, calcium intake and health variables. results The cyclists had lower BMD for all measured sites compared with the runners (p≤0.05). Ten of 19 cyclists were classified as having low BMD according to American College of Sports Medicine criteria (Z-score ≤−1), despite reporting to train heavy resistance training on the lower extremities. Low BMD was site specific having occurred in the lumbar spine and the femoral neck and was not confined to females. Type of sport was the only factor significantly associated with low BMD. Conclusion National elite Norwegian road cyclists had lower BMD compared with runners, and a large proportion was classified as having low BMD, despite having performed heavy resistance training. Interventions to increase BMD in this population should be considered.

Participation in Elite Sport in Youth and Its Impact on Lifelong Bone Health

“…Relative energy deficiency in sport (RED-S), a common phenomenon, can be detrimental to improvement and overall health in sport [20], which may negatively impact BMD in both sexes [21]. Energy availability has shown correlations with vitamin D levels, which may be relevant for bone health [22]. Low BMD is a risk factor for stress fractures, a particular risk for elite athletes of either sex whose careers may be ended prematurely as a result of injury [23,24].…”

“…While some studies have suggested that elite sport participation may have contemporaneous benefits for bone health [22,[27][28][29], this review has highlighted the paucity of research data available regarding this important topic. Longitudinal studies are required, with consideration given to menstrual status in females and vitamin D status in all athletes.…”