Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Osteoporosis ?
    ### Response:
    If you have osteoporosis, ask your doctor which activities are safe for you. If you have low bone mass, experts recommend that you protect your spine by avoiding exercises or activities that flex, bend, or twist it. Furthermore, you should avoid high-impact exercise to lower the risk of breaking a bone.
    