Exercise and Osteoporosis

Learn how exercise can be a strategic prevention and treatment strategy for osteoporosis

Osteoporosis has been called a silent disease because often no symptoms appear until a fracture occurs. Women may not know they have osteoporosis until their bones become so weak that a sudden strain, bump, fall or even sneeze can cause a fracture or reveals a seriously deteriorated vertebrae. The National Osteoporosis Foundation (NOF) states that this condition is a major public health threat for more than 28 million Americans, 80% of whom are women.

Everyone loses bone as they age, but not everyone develops osteoporosis. A variety of factors, some controllable and some not, determine who is at risk. These are some of the major risk factors:

Gender: Women are more likely to develop osteoporosis than men because they have a lighter, thinner bones to begin with and lose bone rapidly after menopause. However, men to account for about one-fifth of the osteoporosis cases in the United States.

Age: The longer a person lives, the more likelihood of developing osteoporosis. One third of American women over the age of 50 eventually will have a spinal fracture.

Family History: Reduced bone mass and susceptibility to fractures may be influenced by heredity.

Body Size: Thin small-framed women and men tend to be at an increased risk than others. But being heavy is no guarantee that you will not get osteoporosis.

Ethnicity: Caucasians and Asian women are at higher risk of developing osteoporosis than African American women. Hispanic populations have an intermediate risk.

Lifestyle: Inadequate calcium and vitamin D intake is harmful to bone health while excessive consumption of other nutrients such as protein, fiber, and sodium can decrease calcium absorption. People who are inactive or bedridden are at higher risk for osteoporosis. Smoking is damaging to bones. Drinking caffeinated or alcoholic beverages in excess is also a risk.

Certain medications: Long-term, high dosage use of glucocorticoids (anti-inflammatories used to treat asthma, arthritis, and some cancers) can lead to bone tissue loss. High dosages of antiseizure drugs cause less calcium to be available for bone remodeling. Bone loss can also result from excessive thyroid hormone, diuretics excluding thiazides).

To find out if you are at risk for osteoporosis, it is useful to check the list of risk factors, but it's not enough. The only way to be sure about your bone condition is through medical tests that measure bone mineral content in various sites. Bone is living, growing tissue that is constantly being renewed. In this ongoing process, old bone is removed and new bone is formed.

There are two types of bone: trabecular and cortical. Trabecular bone comprises the porous interior of the bone. With a texture similar to a honeycomb, it acts as a cushion and a reservoir for calcium. Cortical bone is the dense outer portion of the bone. It offers maximum protection and strength, and accounts for 80% of total bone.

Both types of bone are found throughout the body in varying proportions. The vertebrae and ends of the long arm an leg bones contain the highest percentage of trabecular bone. Since the bone loss of osteoporosis occurs most rapidly in trabecular bone, these areas of the hip, spine, and wrist become the most vulnerable.

Some of the types of bone density tests include single photon absorptiometry and dual-energy x-ray absorptiometry (DEXA). These tests are non-invasive and painless, and are available in hospital and clinical settings. In addition, biochemical markers of bone remodeling can allow determination of the rate of bone turnover. This is usually done with a urine test.

It is recommended that most menopausal women, have a baseline bone density test. This enables you to assess your risk of fracture and take steps to prevent further bone loss. It is useful information for selecting the safest form of aerobic exercise and the appropriate strength-training workout.

EXERCISE:

In 1892, a German medical researcher observed that bone architecture was influenced by mechanical stresses. This led to the development of Wolff's Law, which states that bone remodeling is directly dependent on the mechanical load place upon it.

Bone responds to the work your muscle places on it. For example, in a biceps curl, the shortening and lengthening of a muscle while moving a weight works the muscle. To work bone you have to work muscle. And the one that benefits is the one related to the specific muscle you work. The bone benefits of exercise are site specific. This is one reason why it's necessary to have a balanced exercise program that works all the muscles.

Nearly a century after the formulation of Wolff's Law, the National Institute of Health recognized this principal in practical terms at their 1984 Health Consensus Development Conference on Osteoporosis. A number of research studies have confirmed that exercise can help build bone mass in younger women and build or maintain bone mass in postmenopausal women. Unlike any other intervention strategy for bone health (hormonal and non-hormonal), exercise has an effect on the other risk factors for osteoporotic fractures, by improving balance, strength, and increasing muscle mass. All of which helps prevent a fall and subsequent fracture.

If you have been diagnosed with osteoporosis and have perhaps suffered from a fracture due to this condition, there's no reason you can't enjoy all the fun and health benefits of exercise. Physical activity is not a substitute for medical intervention, it is an adjunct to an overall health and well-being.

However, if you have been diagnosed with the disease there are some special considerations when exercising. You should avoid any movements that bend forward from the waist, twist the spine or any high risk activities.

The goal is to participate in a weight bearing aerobic activity (being on your feet) for a duration of thirty minutes or more (may be done all at once or broken into smaller segments) at 55%-80% of your maximum heart rate (220-age=Maximum Heart Rate), three to five days a week and strength training two days a week, working all the muscles of the body. Choose a weight you can comfortably lift about 10 times. Fancy equipment or making
your home into a gym is not necessary. Those old five-pound weights that have been lying around for years will do just fine. Play around with your exercise choices. Remember weight-bearing is best for bone, but choosing the one your enjoy is a personal preference.

Thus, exercise is an important component of an osteoporosis prevention or treatment program, but it is not a substitute for osteoporosis medications and/or calcium supplementation in preventing bone loss in postmenopausal women. Set realistic goals. Exercise with moderation. It is also recommended before beginning any exercise program to consult with your healthcare provider.

Remember, a regular exercise program can have many benefits. It helps fight osteoporosis by maintaining bone strength, and it reduces the likelihood of falling by improving coordination, balance, and muscle strength. It also strengthens your heart lungs and increases your energy and stamina. Exercise improves your appearance by toning muscles and keeping weight off. You'll look and feel great.

Written by: Lisa Hoffman, M.A.
Excerpts from her book: Better Than Ever: The 4-Week WorkOut Program for Women Over 40