Osteoporosis Tips: Build Stronger Bones
Exercise Your Right to Strong Bones
One way to see just how important exercise is to bone health is to look at what happens to bone strength when people don't exercise.
“People who have been put on bed rest, people who undergo limb immobilizations, and astronauts, who have very reduced physical activity because of the minimal actions of gravity and muscles pulling on the bone -- they all see a rapid and profound effect on the skeletal system,” says Wendy Kohrt, PhD, a professor of medicine and the director of research for geriatric medicine at the University of Colorado. “People confined to bed rest for even four months lose about 10% of their bone density in critical regions of the skeleton. It takes a very long time to get that back.”
Kohrt says the evidence shows that weight-bearing exercise can build about 1% to 3% of bone. That may not sound like a lot, but exercise may also strengthen existing bone in ways that are harder to quantify. Research from the landmark Nurses' Health Study (NHANES) shows that women who walk at least four hours per week reduce their risk of hip fracture by about 40%.
Weight-bearing exercises include walking, dancing, jogging, playing tennis. Swimming, although it's a wonderful exercise in many ways, doesn't particularly benefit bone health because it isn't a weight-bearing activity.
“I think that just being physically active, being up on your feet and doing a variety of things, probably has benefits that we can't necessarily measure if we study a small group of subjects over a brief interval of time like one year,” says Kohrt. “But if we look at a large population of people followed for many years, that level of activity has benefits for your bones.”
There are also things you shouldn't do if you want to take care of your bones. Tops on the no-no list: smoking. “That's definitely bad for your skeletal health,” says Kohrt. Significant bone loss has been found in men and women who smoke, and the more and longer you smoke, the greater your risk of fracture. Some studies even suggest that secondhand smoke exposure in youth can increase the risk of low bone mass as an adult.