STRONG BONES: How to Build Them and Keep Them
Bones are like massive bridges. They have to support an enormity of weight and pressure. Yet important maintenance must somehow be accomplished while the structure is still in use. Small areas are constantly being broken down and reformed: sections get removed and stronger new bone is deposited. In youth, bones grow in width, length and increase in density until about age 30. From then on breakdown is faster than bone formation, and density begins a gradual decline. Or the rate can be speedy depending on your lifestyle.