Long Distance Running And Rest Are Associated With Improved Bone Health

Running is traditionally considered harmful to bone health, yet few studies use robust radiological outcomes to examine this. PURPOSE: To determine the association between running and bone health. METHODS: This cross-sectional study included 81 males aged 36-79 who reported running 1-60 years, averaging 2.4-152.9 km/week across 1-6 days. Outcomes included bone mineral density (BMD) at the lumbar spine, total hip, and femoral neck via dual-energy x-ray absorptiometry. Predictors included historical (questionnaire) and current (actigraphy) physical activity.Analyses were performed using Stata v17 (StataCorp, Texas, USA). Linear regressions assessed associations between BMD and running/physical activity measures, with stepwise multiple regression using adjusted α levels (0.10 entry, 0.20 removal). A significance level of α = 0.05 was set for all other analyses. RESULTS: Lumbar spine BMD (g/cm2) was associated with light physical activity (β [95% CI]: -0.012 [-0.019, -0.004]) and energy expenditure (0.00008 [0.00003, 0.00014]). Total hip BMD was associated with light activity (-0.010 [-0.016, -0.003]), years running (0.003 [0.001, 0.005]), and energy expenditure (0.00006 [0.00001, 0.00010]). Femoral neck BMD was also associated with light activity (-0.011 [-0.016, -0.005]) and energy expenditure (0.00006 [0.00002, 0.00010]). Similar trends were observed for t-scores, while z-scores related to years of running rather than energy expenditure. Greater energy expenditure and running years positively correlated with bone health, while higher light activity correlated with poorer bone health. CONCLUSIONS: Our findings challenge the view that running harms bone health and support long-term running as beneficial for bone health, with triaxial accelerometry showing positive associations with energy expenditure. Osteoblast function declines with age, limiting new bone generation in response to exercise, yet running may mitigate BMD loss by decreasing osteoclastic activity. Endurance running should be encouraged for improved bone health in aging populations, with rest intervals advised for optimal osteogenic benefits. Long-term studies on running and bone health are recommended.