[Physical training].

Physical training repairs bone structures and increases bone mass as well as the most effective medicine, through inducing piezo-electric potential and stimulating osteoblastic activity. Although gain of bone mass depends on duration and intensity of mechanical loading, researches have shown that daily 30 minutes' mild training such as walking has positive effect on increasing bone mass, even in elderly persons. Compared with calcium intakes or sun exposure, habits related to bone metabolism, physical activity is significantly greater to increase bone mass. Interestingly, it is apparent in our study that habitual stroll walks of older age groups prevent the falls which is another risk of their fracture in the extremities.