Article Title



Olivia K. Anderson, Allen L. Redinger, Shawn M.F. Allen, Mia C. Young, Taylor K. Dinyer-McNeely and Breanne S. Baker

Oklahoma State University, Stillwater, OK

Previous studies suggest women using hormonal contraceptives (HC) may have reduced skeletal benefit from exercise, contributing to reduced bone mineral density (aBMD) and content (BMC). Further research will assist women competing in sports with a high prevalence of low aBMD and fracture risk, such as cross-country and track and field (XC+T&F). PURPOSE: To compare total body and site-specific bone measures using Dual-energy X-ray Absorptiometry (DXA) between different groups of XC+T&F athletes based on three menstrual cycle categories: 1) naturally menstruating, normal cycle (NM), 2) naturally menstruating, irregular/absent cycle (NMI/A), 3) HC users (HC). METHODS: Twenty-five NCAA Division I XC+T&F sportswomen (NM n=9, NMI/A n=8, HC n=8) provided voluntary informed consent prior to completing training, injury, sleep, and menstrual questionnaires. Additionally, all participants completed total body, lumbar spine (L1-L4), and dual hip DXA scans and knee extension maximal voluntary contractions with surface EMG on the vastus lateralis. One-way ANOVAs with Least Significant Differences post hoc analyses were used to assess menstrual group differences for all dependent variables. Lastly, partial eta2 (pη2) were used to convey effect size and α=0.05. RESULTS: From the total body scan, left and right rib (Figure 1-A), L1-L4 aBMD and BMC, and pelvis aBMD were greater in HC than NMI/A (post hoc p≤0.017; pη2≥0.391) and L1-L4 BMC and aBMD were greater in HC than NM (all post hoc p≤0.049; pη2≥0.468). Site-specific L1-L4 scans showed aBMD (Figure 1-B) was also greater in HC than NMI/A (post hoc p≤0.015; pη2≥0.473) and trending greater in HC than NM (p=0.054). All groups were similar for all anthropometrics, questionnaire responses, muscular strength, and neuromuscular performance measures (p≥0.088). CONCLUSION: These data suggest HC usage may be skeletally protective as HC users had either the same or greater bone indices at all sites compared to NM and NMI/A athletes.

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