Differences in female athlete triad risk factors between Japanese and American female runners: A comparative study.
Ana Carla C Salamunes, Natsue Koikawa, Nancy I Williams and 7 others
PMID 41669996WHAT IT FOUND
Japanese female runners had a higher prevalence of stress fractures and energy deficiency risk factors than American runners, despite similar rates of diagnosed eating disorders and low bone mineral density.
This suggests Japanese athletes in this cohort faced greater overall Triad risk.
Key findings
01A significantly higher proportion of Japanese runners reported experiencing stress fractures compared to American runners (50% vs 17%).
02More Japanese runners had at least one energy deficiency risk factor (55%) compared to American runners (32%), though no single risk factor like low BMI or low TT3 differed significantly between groups.
03Japanese runners had significantly lower bone mineral density at the lumbar spine, total hip, and femoral neck, but similar Z-scores to American runners, suggesting differences were driven by body size rather than bone health alone.
STILL TO COME
How it was doneWhat they foundWhat it means for PTsWhat it means for OTs
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What it does not show
The study compared two different countries using different DXA scanners and hormone assay platforms, which may affect comparability. Dietary and exercise data were self-reported, introducing potential recall bias. A significant amount of data was missing for some outcomes, such as exercise logs for 15 Japanese runners and dietary logs for 14 American runners. The cross-sectional design cannot determine causality between energy availability and stress fractures. The sample size was small and limited to runners aged 17-25, so findings may not generalize to older athletes or other sports.
Declared interests
The Japanese data was supported by the Japan Sports Agency. The authors declared no conflicts of interest.
The easy way to misread this
Do not assume the lower bone mineral density in Japanese runners indicates poorer bone health. The study found that Z-scores were similar or higher, meaning the lower density was likely due to smaller body size rather than pathological bone loss.
Summarised by AI from the full paper, without a clinician reviewing it. Check it against the source before it changes what you do. Read it on PubMed →