By Noel Pollock, Claire Grogan, Mark Perry, Charles Pedlar, Karl Cooke, Dylan Morrissey, and Lygeri Dimitriou in International Journal of Sports Nutrition and Exercise Metabolism, 2010, 20 419-426.
In a recent cross-sectional study by Pollock and colleagues, the associations between bone mineral density (BMD), menstrual status, disordered eating, and training volume were explored in 44 elite female endurance runners with a mean age of 22.9 years. Seven runners were followed longitudinally and this investigation represents one of the few studies with follow-up data in this subgroup of elite-level athletes. Bone density measurements were completed using DXA. Training and menstrual history were obtained using in-house questionnaires. The Three Factor Eating Questionnaire (TFEQ) was completed to assess eating behavior. For the longitudinal analysis, a follow-up DXA scan was completed 6-14 months from baseline. The investigators demonstrated that menstrual dysfunction, disordered eating, and low BMD were coexistent in 15.9% of the runners. However, there were no significant relationships (p>0.05) between BMD and menstrual status, disordered eating, and training volume, respectively. Interestingly, a significant positive association was found between a reduction in BMD at the lumbar spine and training volume (p=0.026). Therefore, these findings indicate that Triad-related complications exist in elite female endurance runners and furthermore, that low BMD and osteoporosis are prevalent. Pollock and colleagues also found that normal menstrual status did not significantly relate to normal BMD. To this end, it is notably imperative that female endurance athletes complete a DXA amongst their pre-participation screening. Furthermore, future research should investigate this association between high training volume, potential menstrual dysfunction, and reductions in lumbar BMD in larger populations of female endurance athletes. Based on these findings, it is indirectly suggested that a negative energy balance is a contributing factor to bone loss in these athletes.