Exercise can help build bone density.
By Jennifer Brown Bonniwell
Carolyn Leake was diagnosed with osteoporosis when she was 53. Her bone-density tests showed that her bones were so weak and brittle that her doctor told her that she should stand against a wall to prevent breaking a rib when she coughed or sneezed. She was told she could break a bone if she carried her own groceries or lifted too much wet laundry out of the washer.
“I was scared to ride a bicycle because if I fell I would shatter like a teacup,” Carolyn says. “For two days I just cried. And I thought, This can’t be it. I’m only 53. But I realized that I had the bones of an 80-year-old—53 didn’t matter at all.”
Now 67, Carolyn has brought her bone-density level—called a T-score—out of the range of osteoporosis through a combination of bone-strengthening medication, a better diet, and exercise. Yes, that’s right: exercise is good for bones.
For the past decade, Carolyn has walked 3 miles every day—sometimes with a weight vest—and does leg lifts and arm curls with weights in her basement. Her diligence has paid off: she has not broken a bone, and she is still strong enough to work up a sweat gardening in her backyard in Dixon, Illinois.
“I feel 100 percent better. Not only because I’m strengthening my body but because I am also hopefully
protecting and extending my independence by preventing falls because of my stronger body and better balance,” she says. “I’m doing this because I don’t want to end up in a wheelchair with a broken back.”
Carolyn’s decision to integrate regular exercise into her life has now become the standard recommendation for nearly all women facing osteoporosis.1 While many women still need to take bone-strengthening medication to prevent serious bone fractures, studies show that exercise is a safe and effective way to strengthen bones and prevent bone fractures due to osteoporosis in postmenopausal women.2
Even women who have not been diagnosed with osteoporosis can benefit from exercises to strengthen bones. In fact, experts now recommend that women begin strengthening their bones in their teens to help counteract the natural bone loss that all women face as they age.3
Bone Loss and Rebuilding
As we age, our bones constantly grow and rebuild. In our early years, bone rebuilding outpaces bone loss, so bones grow larger and denser. Bones grow at the fastest pace during adolescence and reach peak bone mass at around age 20 to 30.4
Then, through the natural aging process, bone loss begins to outpace bone rebuilding. Bone loss speeds up in women after menopause, as estrogen, a hormone that helps protect bones, decreases. Other factors that can contribute to bone loss include smoking, drinking more than two or three servings of alcohol daily, a family history of osteoporosis or bone fractures, and consuming inadequate levels of calcium and vitamin D.5
Osteoporosis, a bone condition that literally means “porous bones,” occurs when the rate of bone loss is greater than that of bone rebuilding, causing thin and brittle bones that break easily. Researchers estimate that 30 percent of women over 65 have osteoporosis, though far fewer women have been diagnosed with the condition.6 The impact of weak and easily broken bones on a woman’s quality of life is significant and can include limitations on movement, painful injuries, and repeated hospitalizations. In the most severe cases, even sneezing can cause bone fracture.7
Doctors screen for osteoporosis using a bone-density test. The result is expressed as a T-score, which shows how much a patient’s bone mass deviates from the average bone mass of a healthy adult. A normal T-score is between +1.0 and –1.0. A T-score of less than –2.5 at the femoral neck or spine is typically considered to be within the range of osteoporosis.8
Exercise Helps Women Continue to Build Bone
Even though bone rebuilding naturally slows as we age, regular weight-bearing and resistance exercise can increase rebuilding. Exercise causes the muscle to contract against the bone. This action stresses or stimulates the bone, spurring the bone to become stronger and denser.9
Miriam E. Nelson, PhD, director of the John Hancock Research Center on Physical Activity, Nutrition, and Obesity Prevention and associate professor of nutrition at the Friedman School of Nutrition Science and Policy at Tufts University, has been researching bone health in women since the late 1980s, when she co-authored a study for the National Institutes of Health to examine how strength training affects bone density in middle-aged and older women.10
The study was pivotal in bone health research, Dr. Nelson says, because it changed the way we think about bone loss—and the potential for rebuilding. “Most people thought that you got to 35 and then you [experienced only bone loss], but this study showed that women in their fifties who have been sedentary can gain bone density.” To understand how this works, Dr. Nelson says, it’s key to look at the mechanics involved: “Bone adapts to novel forces,” she says, “so if you start doing something very different, the bone adapts. Just like our bodies are very adaptable, so the bones adapt when you start doing something different.”
Since then new research confirms that exercise has a positive impact on bone health, though the amount of impact is still not certain. A 2011 Cochrane review of current research found “a relatively small statistically significant, but possibly important, effect of exercise on bone density compared with control groups.”2 In other words, exercise is good for your bones, but the extent of the possible benefit is still unknown.
The Power of Exercise
“When we exercise, we put pressure onto the bones and the bones
respond by getting stronger,” says Karen Kemmis, PT, DPT, MS, a physical therapist and exercise physiologist at SUNY Upstate Medical University and a member of the National Osteoporosis Foundation’s Nursing Advisory Council, which focuses on educating nurses about osteoporosis.
The key to bone strengthening is stimulating the bone with weight-bearing or resistance exercises. This could include weight lifting in a gym or exercises involving lifting a person’s own body weight, such as pull-ups or push-ups (see sidebar “Best Bone-Strengthening Exercises”).
Vary Strength-Training Exercises to Stimulate Bones
The best exercises for bone health are weight-bearing and resistance exercises that stimulate the bone beyond the impact of daily activities. In general, Kemmis says, these exercises include “everything where you pick up your foot and set it down,” though she notes that “not all exercises are for everybody. Stay safe with an amount of impact that is appropriate for each person.”
It is also important to change the exercises you use to stimulate the bones. Bones will get stronger only if the body intuits that the bones need to rebuild to meet a new activity or exercise, Kemmis says. “When we do our normal activities, our bones get used to that activity. If I do the same thing every day, my bones have the exact same strength. To strengthen, it has to be over and above what we do in normal life. It always has to be a little bit more.”
Not All Exercise Strengthens Bones, Experts Say
Swimming and bicycling do not have the same bone-strengthening benefits as running and tennis because they do not put stress on the bones. The same is true for yoga and Pilates, which typically involve smooth movements and little or no impact-based exercise.11
“Swimming is almost like going antigravity, into space,” Kemmis says. “It is good exercise for your heart and lungs, but it is not helpful for the bones.”
So, what should you do if you are recovering from an injury or have some other problem that makes it difficult to do impact-based activities? Keep doing whatever exercise you like best. Then review your activity with a trainer or physical therapist to supplement with strength training.
One Woman’s Story
Carolyn Leake did not know that she was at high risk for osteoporosis until she was diagnosed with a very severe case of the disease. In 1999 her bone-density T-score measured as high as –3.6.12 She was well below –2.5, which is considered the beginning of the range for osteoporosis. The greater the negative number, the more severe the condition.
The diagnosis came as a shock to her. But after she saw a list of the risk factors, she says she probably should not have been surprised: “I met, like, eight of the 10 risk factors.”
Among those risk factors were that she had been a lifelong smoker (though she had quit a few years before she was diagnosed with osteoporosis) and she rarely drank milk or ate calcium-rich dairy products. Her mother also had osteoporosis—though Carolyn didn’t know that at the time of her own diagnosis—and later broke her hip. In addition, at just 87 pounds, Carolyn’s slight build put her at risk because her bones didn’t naturally have to carry as much weight.
Carolyn’s doctor prescribed Fosamax® (alendronate), one of the most well known of the bone-strengthening drugs. She has been on Fosamax or a similar medication since then. She also altered her diet to include more calcium. And she began exercising. Carolyn now walks every day, though she is still afraid of falling on icy streets in the winter, so she walks on a treadmill when it is cold.
Carolyn also has started taking a weight-training class called Strong Women Strong Bones, based on the exercise program developed by Dr. Nelson. The program aims to teach women how to exercise in ways that strengthen bones. For example, Carolyn says she never realized that she should increase the intensity of her exercises by adding weight rather than simply doing more repetitions.
“It is a lot of work, but I’m just frightened to death. I didn’t want to break my back and end up in a wheelchair,” she says. “I am very fortunate that I was diagnosed as young as I was. I decided that I didn’t want to let it beat me.”
Are You at Risk of Osteoporosis?
Some of the factors your doctor will consider to determine if you are at higher risk of developing
- Whether you have reached menopause
- If your parents have broken a hip or if they have osteoporosis
- If you have had broken bones as an adult
- Drinking more than two or three servings of alcohol per day
- Dietary habits, including calcium and vitamin D intake
- Whether you have had an eating disorder such as anorexia nervosa
- Whether you have had regular periods (premenopausal women)
- Whether you take any medicines or have any medical conditions that may cause bone loss
National Osteoporosis Foundation; nof.org/aboutosteoporosis/detectingosteoporosis/diagnosing.
Best Bone-Strengthening Exercises
Some of the best bone-strengthening exercises include:
- Jogging or running
- Tennis or racquetball
- Field hockey
- Stair climbing
- Jumping rope
- Weight lifting
- Weight-bearing exercises such as push-ups and pull-ups
National Osteoporosis Foundation;
US Department of Health and Human Services Office on Women’s Health.
Detecting and Treating Osteoporosis
By Kari Bohlke, ScD
To detect osteoporosis the US Preventive Services Task Force recommends routine screening of women age 65 and older. Screening may need to begin at a younger age for women at increased risk of osteoporosis.
The most common bone-density test is a DXA (dual-energy X-ray absorptiometry) test, which measures your bone mineral density and compares it with an established standard. If the test indicates that you have osteoporosis, the condition can be treated. Treatment of osteoporosis reduces the risk of fracture.
Drugs known as bisphosphonates have been used for many years to treat osteoporosis. Bisphosphonates include Fosamax® (alendronate), Actonel® (risedronate), Atelvia® (risedronate), Boniva® (ibandronate), and Reclast® (zoledronic acid).
A newer drug called Prolia® (denosumab) was approved in 2010 for postmenopausal women with osteoporosis and a high risk of fracture. The drug has also been shown to increase bone mass among patients undergoing certain types of cancer treatment. Prolia targets a protein known as the RANK ligand. This protein regulates the activity of osteoclasts, the cells that break down bone.
Other osteoporosis treatment options include Evista® (raloxifene), Forteo® (teriparatide), calcitonin, and estrogen. All osteoporosis medications have potential side effects, and your doctor can help you make a decision that balances the benefits of treatment against the risks.
If you are found to have lower-than-normal bone mass (but not osteoporosis), your doctor may talk with you about how to reduce further bone loss. Not everyone with low bone mass develops osteoporosis, but low bone mass does increase the risk.
Screening for Osteoporosis. US Preventive Services Task Force website. Available at: http://www.ahrq.gov/clinic/uspstf/uspsoste.htm (Accessed April 9, 2012).
The following websites provide education, support, and other resources related to preventing osteoporosis and promoting healthy bones.
National Osteoporosis Foundation nof.org
US Department of Health and Human Services Office on Women’s Health
Best Bones Forever! bestbonesforever.gov/index.cfm
A website aimed at girls and their BFFs to promote healthy bones during the prime bone-building adolescent years, from the US Department of Health and Human Services Office on Women’s Health
1. Exercise for Healthy Bones. National Osteoporosis Foundation website. Available at http://www.nof.org/aboutosteoporosis/prevention/exercise (Accessed April 12, 2012); The 2004 Surgeon General’s Report on Bone Health and Osteoporosis. Available at http://www.surgeongeneral.gov/library/bonehealth/docs/OsteoBrochure1mar05.pdf (Accessed April 12, 2012).
2. Howe TE, Shea B, Dawson LJ, et al. Exercise for preventing and treating osteoporosis in postmenopausal women. Cochrane Database of Systematic Reviews. July 6, 2011;(7):CD000333.
3. Best Bones Forever! National Osteoporosis Foundation website. Available at http://www.nof.org/awareness/bestbonesforever (Accessed April 12, 2012); The 2004 Surgeon General’s Report on Bone Health and Osteoporosis. Available at http://www.surgeongeneral.gov/library/bonehealth/docs/OsteoBrochure1mar05.pdf (Accessed April 12, 2012).
4. Calcium and Bone Health. Centers for Disease Control and Prevention website. Available at: http://cdc.gov/nutrition/everyone/basics/vitamins/calcium.html (Accessed April 12, 2012); National Osteoporosis Foundation; National Center for Biotechnology Information, U.S. National Library of Medicine.
5. Calcium and Bone Health. Centers for Disease Control and Prevention website. Available at: http://cdc.gov/nutrition/everyone/basics/vitamins/calcium.html (Accessed April 12, 2012).
6. Osteoporosis among estrogen-deficient women—United States, 1998-1994. Morbidity and Mortality Weekly Report. 1998;47:969-73. Among a study group of 2,314 women over age 20, 17 percent met the World Health Organization’s definition of osteoporosis and only 5 percent reported that they had been diagnosed with osteoporosis.
7. What Is Osteoporosis? National Osteoporosis Foundation website. Available at http://www.nof.org/aboutosteoporosis/bonebasics/whatisosteoporosis (Accessed April 12, 2012).
8. Detecting Osteoporosis. National Osteoporosis Foundation website. Available at http://www.nof.org/aboutosteoporosis/detectingosteoporosis/bmdtest (Accessed April 12, 2012).
9. Miriam Nelson, PhD, director of the John Hancock Research Center on Physical Activity, Nutrition, and Obesity Prevention and associate professor of nutrition at the Friedman School of Nutrition Science and Policy at Tufts University.
10. Nelson ME, Fiatarone MA, Morganti CM, Trice I, Greenberg RA, Evans WJ. Effects of high-intensity strength training on multiple risk factors for osteoporotic fractures. Journal of the American Medical Association. 1994;272(24):1909-14.
11. Karen Kemmis, PT, DPT, MS; Dr. Miriam Nelson, PhD.
12. Carolyn said her T-scores were –3.6 and –3.0, with the two measurements for two different parts of her body. Bone mass tests are typically measured at the hip and the spine. Carolyn did not remember which score corresponded to which part of her body.