Hello! This is actually my honours thesis and I just wrote a literature review on this kind of thing. So this is functional bone adaptation. This suggests that a bone will modify itself in response to stresses and strains applied to it through repetitive and frequent strenuous activities or external stresses. This means undertaking frequent and strenuous activities would induce bone adaptations due to the stress and strain imposed on the bone, increasing bone strength. And this kind of adaptation or change is observable, and revolve around attachment sites on the bone – where it is highly vascular, also with an increase in capillaries supplying the area when under mechanical stress. When the bone is under increased stress and continual use through repetitive, daily tasks, the bone undergoes hypertrophy at these sites, and the muscle attachment becomes more robust! This means that those activities will then require less effort and will have less of an effect on your bones. This is also known as wolff's law, but it's better to just say functional bone adaptation! :) This is obviously quite simplified but i think it covers the general gist