To identify the prevalence of male and female athlete triad risk factors in ultramarathon runners and explore associations between sex hormones and bone mineral density (BMD).
Multiyear cross-sectional study.
One hundred-mile ultramarathon.
Competing runners were recruited in 2018 and 2019.
Assessment of Risk Factors:
Participants completed a survey assessing eating behaviors, menstrual history, and injury history; dual-energy x-ray absorptiometry for BMD; and laboratory evaluation of sex hormones, vitamin D, and ferritin (2019 cohort only).
Main Outcome Measure:
A Triad Cumulative Risk Assessment Score was calculated for each participant.
One hundred twenty-three runners participated (83 males and 40 females, mean age 46.2 and 41.8 years, respectively). 44.5% of men and 62.5% of women had elevated risk for disordered eating. 37.5% of women reported a history of bone stress injury (BSI) and 16.7% had BMD Z scores <−1.0. 20.5% of men had a history of BSI and 30.1% had Z-scores <−1.0. Low body mass index (BMI) (<18.5 kg/m2) was seen in 15% of women and no men. The Triad Cumulative Risk Assessment classified 61.1% of women and 29.2% of men as moderate risk and 5.6% of both men and women as high risk.
Our study is the first to measure BMD in both male and female ultramarathon runners. Our male population had a higher prevalence of low BMD than the general population; females were more likely to report history of BSI. Risk of disordered eating was elevated among our participants but was not associated with either low BMD or low BMI.