Bone and Body Composition Adaptations to Physical Training

The goal of this clinical trial is to evaluate how different exercise programs alter bone density, structure, and strength in adults. It will also collect data on hormones, factors released from skeletal muscle, and body composition. The main questions it aims to answer are: * Do exercise programs that are frequent with high-impact loading will cause greater improvements in bone health? * What changes in hormones, factors released from skeletal muscle, and body composition contribute to bone adaptations? Researchers will compare different exercise groups to see if the type of exercise influences bone adaptation compared to a recreationally active control group. Participants are asked to: * complete questionnaires, 5 blood draws across the study (3 at rest, 2 after strenuous exercise), dual energy x-ray absorptiometry (DXA) scans (to assess bone mineral density and body composition), high resolution tibial scans to assess bone structure and geometry, and physical performance testing. * attend up to 7 testing visits. * (for those randomized to the exercise training intervention) participate in exercise training sessions for 6 months.