How does exercise maintain healthy bones?

a) by reducing the need for calcium

b)by making bones grow stronger and denser

c)by reducing the need for phosphorus

d)by making the outer membranes stronger

it's really a mix of B,C and D . But while there are some exercises that help with the building of Bones, exercise itself does not build bones, it build muscle. And exercising helps improve overall brain health, and muscle health thus helping the bones get stronger and denser keeping you more able to lift and move and to absorb the right nutrients you need..,..hope that helps : )

1. they vary with a higher number because boiling is way hotter than melting