Moderate-Intensity Exercise Preserves Bone Mineral Density and Improves Femoral Trabecular Bone Microarchitecture in...

Area of Science:

• Gerontology
• Bone Biology
• Exercise Physiology

Background:

• Aging is associated with significant bone loss and increased osteoporosis risk.
• Exercise interventions can mitigate age-related bone loss, but optimal training volumes remain unclear.
• This study investigated the effects of different volumes of moderate-intensity aerobic exercise on bone metabolism in middle-aged mice.

Purpose of the Study:

• To determine how varying volumes of moderate-intensity aerobic exercise affect bone mineral density (BMD), bone mineral content (BMC), and femoral bone microarchitecture.
• To assess the impact on both trabecular and cortical bone structures.
• To provide insights into exercise strategies for preventing age-related bone loss.

Main Methods:

• Twenty middle-aged male C57BL/6 mice were divided into three groups: control (CON), high-volume moderate-intensity exercise (EX_MHV), and low-volume moderate-intensity exercise (EX_MLV).
• Mice underwent 8 weeks of their assigned regimen.
• Femoral BMD and BMC were measured using dual energy X-ray absorptiometry, and micro-computed tomography was used for microarchitecture analysis.

Main Results:

• High-volume exercise (EX_MHV) significantly increased femoral BMD compared to controls (P<0.05).
• Both high-volume (EX_MHV) and low-volume (EX_MLV) exercise significantly increased distal femoral trabecular bone volume/tissue volume (BV/TV) (P<0.05).
• Cortical bone strength at the femoral mid-diaphysis was greater in the low-volume group (EX_MLV) than the high-volume group (EX_MHV).

Conclusions:

• Moderate-intensity aerobic exercise, regardless of volume (low to high), positively influences hindlimb BMD and attenuates age-associated trabecular bone loss in the femur.
• Moderate-intensity aerobic exercise presents an effective and applicable strategy for preventing age-related declines in BMD and bone volume.