Bone and Body Composition Adaptations to Physical Training

The overall objective of this study is to determine the bone density, structure and strength adaptations that result from various exercise programs which differ based on the frequency and intensity of bone loading. Bone adaptation is measured with both dual-energy x-ray absorptiometry (DXA), the standard-of-care equipment used to evaluate bone mineral density (BMD), and high-resolution peripheral quantitative computed tomography (HRpQCT), a state-of-the-science imaging technology providing the resolution necessary to detect small but clinically relevant changes. Additionally, the research team seeks to determine the physiological responses and adaptations to training that contribute to improved bone health by evaluating changes in hormones, factors released from active skeletal muscle, and body composition. Our hypothesis is that exercise programs emphasizing frequent, high impact loading will cause greater improvements in bone health. Additionally, we believe that exercise training can induce specific changes in hormones, skeletal muscle released signaling factors and body composition that contribute to these bone adaptations. Participants who enrolled in this study were randomized to either an exercise training group or a control group who were instructed to maintain their current level of exercise and track this to report to the study team. Study completers were those who complied with the parameters of the group they were assigned and reported to all 7 testing visits.