High-impact Step-aerobic and Progressive Strength Training on Bone Mineral Density in Sedentary Young Women

The purpose of this study was to compare high-impact loaded aerobic exercise and high-intensity strength training on areal bone mineral density (BMD) of the loaded bones in sedentary women, age 20–35 years. Subjects were randomly assigned to: high impact-loaded step aerobic exercise (SA, n=25), high-intensity lower body strength training (ST, n=21) or non-exercise control (CON, n=21). Group differences in BMD were analyzed using ANCOVA. At the 6-month assessment, changes in BMD of the heel (3.5%) and leg (0.9%) were greater (both p<0.05) in the SA than the ST, and change in BMD of total hip and Ward's triangle were greater (p<0.05) in ST (0.3%) than SA (−1.1%). At the 12-month assessment, changes in BMD of the heel in the SA group continued to increase (4.4%, p<0.05). In sedentary young women high-impact activities applied to the heel and lower leg bones produce a positive change in BMD of these two bones, not in bones that are distant from the site of impact. High-intensity strength training of the lower limbs produces a positive change in BMD of the hip and Ward's triangle and not in sites that were distant from the applied force, lumbar spine.