Osteoporos Int. 2025 Dec 1. doi: 10.1007/s00198-025-07766-w. Online ahead of print.
ABSTRACT
Osteoporotic fractures threaten older women’s health worldwide. This nationwide study found that moderate-intensity exercise and vigorous activity performed less than six days weekly lower fracture risk, whereas overly frequent vigorous exercise may increase it. These findings provide practical guidance for balancing exercise intensity and frequency to promote safer activity in aging populations.
BACKGROUND/OBJECTIVES: Osteoporotic fractures, especially vertebral and hip fractures, pose a significant global public health burden due to their high incidence and substantial economic costs. Previous research on physical activity (PA) and fracture prevention has been limited by simplistic classifications of PA and insufficient examination of multidimensional dose-response relationships. This study aimed to elucidate detailed associations between distinct patterns of PA (type, frequency, MET-based volume) and fracture risk, hypothesizing that moderate-intensity exercise provides protective effects, whereas excessive vigorous activity paradoxically increases fracture risk.
METHODS: We conducted a retrospective cohort study using the Korean National Health Insurance Service (NHIS) database, including 541,770 women aged 66 years, with an average follow-up of 7.3 years. Baseline PA was assessed via standardized questionnaires measuring weekly frequency of vigorous (8 METs), moderate (5 METs), and walking activities (3 METs), categorized into MET quartiles. Bone mineral density (BMD) was classified as normal, osteopenia, or osteoporosis. We employed Cox proportional hazards models, adjusted for demographic and clinical covariates, to evaluate fracture risk. Kaplan-Meier curves visualized cumulative fracture incidences.
RESULTS: Regular moderate-intensity exercise (3-5 days/week) significantly reduced vertebral (HR: 0.862-0.891, all p < 0.001) and hip fracture risk (HR: 0.882-0.890, p < 0.02), especially among the osteopenia and osteoporosis groups. Vigorous activity performed at lower weekly frequencies (< 6 days/week) was also associated with reduced fracture risk, whereas excessive vigorous activity (≥ 6 days/week) paradoxically increased hip fracture risk (HR: 1.241; 95% CI, 1.010-1.525) in osteoporosis participants. Clear dose-response relationships emerged across MET quartiles, with higher activity levels consistently lowering fracture risks in osteopenia (HR Q4 vs. Q1: 0.939; 95% CI, 0.910-0.970) and osteoporosis (HR Q4 vs. Q1: 0.894; 95% CI, 0.866-0.922).
CONCLUSION: Our findings suggest that moderate-intensity exercise (3-5 days/week) appears optimal for reducing fracture risk, while excessive vigorous activity should be approached with caution, especially for older women with compromised BMD. Future studies utilizing objective PA measures and prospective designs are warranted to further validate these recommendations.
PMID:41320717 | DOI:10.1007/s00198-025-07766-w
