High impact exercise increased femoral neck bone mineral density in older men: a randomised unilateral intervention

Introduction: There is little evidence as towhether exercise can increase BMD in oldermenwith no investigation of high impact exercise. Lifestyle changes and individual variability may confound exercise trials but can be minimised using a within-subject unilateral design (exercise leg [EL] vs. control leg [CL]) that has high statistical power. Purpose: This study investigated the influence of a 12 month high impact unilateral exercise intervention on femoral neck BMD in older men. Methods: Fifty, healthy, community-dwelling older men commenced a 12 month high impact unilateral exercise intervention which increased to 50 multidirectional hops, 7 days a week on one randomly allocated leg. BMD of both femurswasmeasured using dual energy X-ray absorptiometry (DXA) before and after 12 months of exercise, by an observer blind to the leg allocation. Repeated measures ANOVAwith post hoc tests was used to detect significant effects of time, leg and interaction. Results: Thirty-five men (mean±SD, age 69.9±4.0 years) exercised for 12 months and intervention adherence was 90.5±9.1% (304±31 sessions completed out of 336 prescribed sessions). Fourteen men did not complete the 12 month exercise intervention due to: health problems or injuries unrelated to the intervention (n=9), time commitments (n=2), or discomfort during exercise (n=3), whilst BMD data were missing for one man. Femoral neck BMD, BMC and cross-sectional area all increased in the EL (+0.7, +0.9 and +1.2 % respectively) compared to the CL (−0.9,−0.4 and −1.2%); interaction effect Pb0.05. Although the interaction term was not significant (P>0.05), there were significantmain effects of time for sectionmodulus (P=0.044) and minimum neck width (P=0.006). Sectionmodulus increased significantly in the EL (P=0.016) but not in the CL (P=0.465); mean change+2.3% and+0.7% respectively, whereasminimumneck width increased significantly in the CL (P=0.004) but not in the EL (P=0.166); mean changes being +0.7% and +0.3% respectively. Conclusion: A 12 month high impact unilateral exercise intervention was feasible and effective for improving femoral neck BMD, BMC and geometry in older men. Carefully targeted high impact exercises may be suitable for incorporation into exercise interventions aimed at preventing fractures in healthy community-dwelling older men

Brief high impact exercise increased cortical mass and trabecular density at regions predictive of femoral neck and trochanteric fracture [Abstract]

Brief high impact exercise increased cortical mass and trabecular density at regions predictive of femoral neck and trochanteric fracture [Abstract

The influence of high impact exercise on cortical and trabecular bone mineral content and 3D distribution across the proximal femur in older men: a randomised controlled unilateral intervention

Regular exercisers have lower fracture risk, despite modest effects of exercise on BMC. Exercise may produce localised cortical and trabecular bone changes that affect bone strength independently of BMC. We previously demonstrated that brief, daily unilateral hopping exercises increased femoral neck BMC in the exercise leg versus the control leg of older men. This study evaluated the effects of these exercises on cortical and trabecular bone and its 3D distribution across the proximal femur, using clinical computed tomography (CT). Fifty healthy men had pelvic CT scans before and after the exercise intervention. We used hip QCT analysis to quantify BMC in traditional regions of interest and estimate biomechanical variables. Cortical bone mapping localised cortical mass surface density and endocortical trabecular density changes across each proximal femur, which involved registration to a canonical proximal femur model. Following statistical parametric mapping, we visualised and quantified statistically significant changes of variables over time in both legs, and significant differences between legs. Thirty-four men aged 70 (4) years exercised for 12-months, attending 92% of prescribed sessions. In traditional ROIs, cortical and trabecular BMC increased over time in both legs. Cortical BMC at the trochanter increased more in the exercise than control leg, whilst femoral neck buckling ratio declined more in the exercise than control leg. Across the entire proximal femur, cortical mass surface density increased significantly with exercise (2.7%; P 6%) at anterior and posterior aspects of the femoral neck and anterior shaft. Endocortical trabecular density also increased (6.4%; P 12% at the anterior femoral neck, trochanter and inferior femoral head. Odd impact exercise increased cortical mass surface density and endocortical trabecular density, at regions that may be important to structural integrity. These exercise-induced changes were localised rather than being evenly distributed across the proximal femur. This article is protected by copyright. All rights reserved

Increases in proximal femur bone strength estimated using finite element models from computed tomography scans following brief, high impact exercise in older men [Abstract]

Increases in proximal femur bone strength estimated using finite element models from computed tomography scans following brief, high impact exercise in older men [Abstract