Activities like walking and carrying groceries, skipping, climbing stairs make your bones work against gravity (the force that keeps us from floating like in space). Bones are living tissue. Weight-bearing physical activity stimulates new bone tissue to form, making them stronger. Also, weight-bearing physical activity makes muscles stronger, and muscles push and tug against bones, making them even stronger.

Swimming which is otherwise a very good exercise for the heart, blood vessels and the body doesn't help in bone health. Ever notice how you feel a lot lighter in a pool? Water cuts down on the pull of gravity, so your bones really don't get a good workout. People in space missions also need to think on compensating for the absence of gravity in their space shuttle.!

Some exercises which are weight bearing are: running, washing your walls, windows, working in the kitchen, washing your scooter, cycle, working in the garden or the farm, manual sweeping, swabbing, washing clothes, walking and carrying groceries, skipping, climbing stairs, playing hop-scotch, kho-kho, flying a kite, football, cricket, basketball, volleyball, playing tag, climbing trees, working in the fields and orchards etc.