Better Your Bone Health
Michael Lasalandra Beth Israel Deaconess Medical Center correspondent
MAY 01, 2011
As we age, our bones thin out and become brittle, a condition known as osteoporosis. There are a number of ways to help prevent this condition, which can lead to broken bones and the myriad of serious health problems sometimes associated with them. One of the most effective preventative strategies is simply to take regular walks.
"Weight-bearing exercise, in which your bones and muscles work against gravity, helps build and maintain bone mass," says Dr. Tamara D. Rozental, an orthopaedic surgeon at Beth Israel Deaconess Medical Center and an Assistant Professor in Orthopedic Surgery at Harvard Medical School.
Weight-bearing exercises are ones in which the feet and legs bear your weight.
"That's where walking comes in," she says. "It's probably the easiest. Running and stair-climbing are also good, as is strength training with weights and weight machines that you find at a gym or health club. But walking for 20 to 30 minutes three times a week is just fine. It works."
Swimming and bicycling, by contrast, aren't as effective in helping to prevent brittle bones.
Dr. Rozental notes that bone is living tissue that responds to weight-bearing exercise by becoming stronger. It becomes stronger and denser as it is put under modest stress.
"Bone remodels in response to stress," she says. "It is constantly being broken down and reformed."
In the case of osteoporosis, more bone is being broken down than is being formed, she notes.
"With a sedentary lifestyle, bone thins," she says. "Stress is necessary to stimulate the cells to form and remodel new bone."
There are other preventative strategies, such as taking Vitamin D and calcium supplements. And there are a number of prescription drugs, known as antiresorptive medications, which are also approved for the prevention and treatment of osteoporosis.
But exercise is often an easy first-line strategy for prevention of brittle bones. Risk factors for osteoporosis include post-menopause, older age, a family history of the disease, being small and thin, and using immunosuppressive medication.
In general, women have a much higher risk than men. Of the estimated 10 million Americans with osteoporosis, eight million are women, according to the National Osteoporosis Foundation.
Fractures can also be life threatening. An average of 24 percent of hip fracture patients aged 50 and over die in the year following their fracture, the foundation says.
A study of nurses showed that those who walked four hours per week gave them a 41 percent reduced risk of hip fractures, compared to those who walked less than an hour a week.
When walking, you're carrying your body weight on your hips and legs, so those are the bones most being strengthened. And with walking, there is less chance of falling — something that is more likely to occur with strenuous exercises, such as running or racquet sports, for example.
There are other good things about walking, Dr. Rozental notes. "It's good for the heart, for weight loss and for mood," she says. "And it's free and can be done just about anywhere."