Millions of Americans suffer from osteoporosis, and the numbers are growing at an alarming rate. Years ago, when the expected life span was only five or six decades, people didn't live long enough to suffer from the advanced stages of osteoporosis. Today, with the average life span close to 80 years, it is more and more likely your older clients will succumb to this debilitating, and sometimes fatal, disease. Fitness professionals who want to stay informed and marketable must prepare themselves for the impending influx of clients who suffer from some degree of osteoporosis.
Just the FactsOsteoporosis affects 15 to 20 million Americans and is linked to 1.5 million fractures a year in people over the age of 50 (Layne & Nelson 1999). The cost of this disease is estimated to be a staggering $1 8 billion a year, and this amount is expected to increase to $62 billion by the year 2020 (Kaplan 1995).
Put simply, osteoporosis is a disease that drains bones of their mineral content and increases their susceptibility to fractures. In the later stages of the disease, wrists often become brittle enough to fracture at the slightest tap, and ribs can fracture in response to a cough or sneeze. The vertebrae in the spine often become as thin as eggshells, leading to compression fractures and a stooped posture. Osteoporosis can attack any bone in the body, but the primary sites are the spine, wrist and hip. The condition is often referred to as "the silent killer," because there are typically no signs or symptoms until someone fractures a hip and takes a crushing fall.
Osteoporosis is more common in women than men, and affects Asian, Native American, Latino and Caucasian women more than African-American women (Allen 1999a). One out of every four women over the age of 60 currently suffers from osteoporosis, and half of all women who have had a hysterectomy will develop the condition (Sara et al. 1999). According to the National Osteoporosis Foundation (NOF), the disease is so pervasive among females that the risk of developing an osteoporosis-related fracture is equal to a woman's combined risk of developing breast, uterine and ovarian cancer (NOF 1999).
In the early stages of osteoporosis, individuals often exhibit no symptoms. However, signs of osteoporosis may develop as people reach their 60s and 70s. As the spinal bones lose their mineral content, sufferers typically become hunched over, a condition referred to as kyphosis, or dowager's hump. This curvature of the spine is often accompanied by pain and psychological distress.
Understanding Bone FormationHealthy bone is a living tissue with a rich supply of minerals, such as calcium and phosphorous. During normal bone formation, which is referred to as bone remodeling, there is an intricate interplay between bone formation and bone resorption, or loss. Under normal conditions, old, bone-eroding cells, or osteoclasts, arc constantly being removed from the bone tissue while new bone cells, or osteoblasts, are being made. This delicate balance of bone formation and resorption must be kept in perfect harmony to maintain normal bone density. If the system becomes unbalanced and more bone is lost than made, osteoporosis occurs.
The human body is made up of two types of bone: cortical bone and trabecular bone. Cortical bone is very dense and opaque, whereas trabecular bone resembles cables on a bridge that crisscross and interconnect to provide stability. As we grow older, both cortical and trabecular bone density decrease, thus weakening the infrastructure of bone tissue.
Risk Factors For Osteoporosis
According to the World Health Organization (WHO), the definitive criterion for having osteoporosis is a spinal bone mineral density (BMD) of 2.5 standard deviations or more below the mean for young, normal adults of the same gender (Kanis et al. 1994). Presently, two methods are commonly used to evaluate bone density: dual energy X-ray absorptiometry (DEXA), which assesses cortical and trabecular bone in the spine and hip; and quantitative computed tomography (QCT), which assesses trabecular bone in thc spine. While these tests are the only way to definitely diagnose osteoporosis, knowing the risk factors can help identify clients who are likely to develop the condition.
Menopause. Menopause is probably the greatest contributor to osteoporosis. Before menopause, women lose approximately 0.3 percent of their bone mineral content each year. After menopause, the annual rate jumps to 2.5 to 3 percent (Kaplan 1995). The female sex hormone estrogen plays a vital role in bone mass and strength. When estrogen is no longer manufactured by the ovaries, calcium in the bones decreases at an accelerated rate. This leads first to osteopenia, which is decreased bone mass, and ultimately to osteoporosis, which is a significant loss of bone mass. According to the NOF, women can lose up to 20 percent of their total bone mass density in the first five to seven years following menopause (NOF 1999). By age 75, bone mass may be one-half of what it was at the age of 30 (Kaplan 1995). Estrogen deficiency also occurs in women who have had a hysterectomy, in female athletes who suffer from amenorrhea and in women with eating disorders, such as anorexia nervosa.
Low Peak Bone Mass During Skeletal Maturity. One of the main causes of osteoporosis is a low rate of bone mineral accumulation during adolescence and young adulthood (i.e., up to age 35), when the skeleton is still maturing. To better understand this concept, think of bone mineral as money in a bank account. The more money (or bone) you accumulate in your peak earning (or bone-producing) years, the lower your risk of depleting your financial resources (or bone density) when you grow older. As far as money and bone go, the longer you live, the more you need to save. Low Calcium Intake. Low calcium intake is another cause of osteoporosis. Adequate calcium intake may be as crucial for maintaining peak bone mass as it is for attaining it. (See "Treatment for Osteoporosis" later in this article for recommended daily intakes for different populations.)
Smoking. Cigarette smoke interferes with the body's ability to produce estrogen. Research has shown that women who smoke a pack of cigarettes a day lose 5 to 10 percent of their bone density by the time they teach menopause (Kaplan 1995). Smoking is also a primary cause of osteoporosis in men (Allen 1999b). Sedentary Lifestyle. Reduced weight bearing, due to disuse or immobilization, leads to progressive thinning and eventual loss of bone. Studies on astronauts found they incurred significant bone loss from being suspended in a gravity-free environment (Kaplan 1995). Individuals confined to bed for several weeks were also shown to have accelerated bone loss (Kaplan 1995).
Genetics. Family history plays a role in most diseases, including osteoporosis. In one study, investigators from Australia evaluated 311 middle-aged women and found that bone density could be predicted on the basis of the women's genetic makeup (Kaplan 1995). It has also been established that a defective gene can impair production of vitamin D, which is needed to help absorb calcium.
Other Risk Factors. Additional factors that contribute to osteoporosis include heavy alcohol drinking (especially in men); low body weight; low testosterone levels: prolonged use of drugs, such as steroids, Dilantin, phenobarbital and thyroid hormone; metabolic diseases; and gastrointestinal disorders (Allen 1999b).
Treatment For OsteoporosisTwo of the cornerstones for treating osteoporosis are calcium intake and exercise. Although drug treatment is also used to prevent or treat osteoporosis, this is outside the scope of this article. (For a complete review of drug treatment options, refer to Sato et al., 1999.)
Calcium IntakeSeveral studies have reported that higher intakes of calcium during childhood and early adulthood result in a 3 to 8 percent increase in bone mass later in life, as well as a reduction in hip and wrist fractures (Kaplan 1995). In one of the most carefully controlled studies to date, researchers observed identical female twins to determine if calcium supplementation was effective in increasing bone density (Kaplan 1995). For each pair of twins, one was given a supplement while the other received a placebo. This double-blind study followed the women for three years. At the end of the study, the calcium supplement group had significantly greater bone mass than the placebo group.
The amount of calcium obtained through diet should be used to determine how much - if any - calcium should be derived from a supplement. Generally speaking, most older adults do not obtain sufficient calcium through diet and should consider supplementation. The National Institutes of Health Consensus Development Conference on Optimum Calcium Intake has established the following recommended daily intake for different age groups:- 1,500 milligrams per day (mg/day) for postmenopausal women who are not taking estrogen and for men 65 and older
- 1,000 mg/day for premenopausal women, for postmenopausal women who are taking estrogen and for men between 25 and 64 years of age
- 1,200 to 1,500 mg/day for teens and young adults 11 to 24 years of age (Kaplan 1995)
In 1892, Julius Wolff was the first to describe how changes in the internal architecture of human bone were directly related to the amount of stress placed on it. In short, he theorized that load-bearing activity would have a powerful effect on the overall shape, size and thickness of bone tissue (Katz & Sherman 1998). This theory holds true today and is referred to as Wolff's Law. (See "The Principles of Wolff's Law" at the end of this article.)
Unfortunately, Wolff's Law applies more to younger individuals than older adults. As mentioned earlier, the research is quite convincing that the more bone a person deposits before age 35, the greater the amount of bone tissue she or he will have in later years. This is not to suggest that increased calcium intake and regular exercise can't increase bone density as one ages. But bone mineral will not accumulate as readily than as in the younger years, when the skeleton is still maturing.
It is still not entirely clear to what extent exercise can improve bone density in older individuals. According to a recent study by Sato and colleagues (1999), "Clearly, exercise has a dramatic effect on bone mass in the growing skeleton and can improve peak bone mass, which will reduce the risk of osteoporosis. However, once the skeleton stops growing, the effect of exercise on bone mass is modest. While exercise might not improve bone mass, it may slow the rate of bone loss and can dramatically improve balance and stability, thus reducing the risk of falling."
Despite such reservations, movement in general is essential to good bone health. Older adults and postmenopausal women need to increase their physical activity levels in order to slow or delay the onset of osteoporosis, and in some instances, make modest improvements in bone mass.
Client AssessmentBefore developing an exercise program for older clients (men over 65 or post-menopausal women), fitness professionals need to determine if a clinical diagnosis of osteoporosis has been made. Since the vast majority of older individuals have never been tested for the condition, it is important to complete the following checklist to determine if a physician should screen the client:
- Is there a family history of osteoporosis?
- Did the female client go through early menopause?
- Has she had a hysterectomy?
- Does the client smoke?
- Does the client have a low daily calcium intake?
- Are there visible signs of osteoporosis (previous fracture, stooped posture)?
- Is the client taking any medication that can increase bone loss (e.g., prednisone)?
Clients who respond yes to any of these questions should be considered at risk for osteoporosis. It should be suggested that they see their physician and have a bone density test performed. (See "Risk Factors for Osteoporosis" at the end of this article.) Based on the test results, the physician will be able to determine how much bone loss has occurred and if this amount meets the criterion for osteoporosis. A physician's input will be invaluable as you develop a safe exercise program for clients with a confirmed diagnosis.
A typical exercise program for senior clients with osteoporosis should incorporate resistance, balance, flexibility and cardiovascular training. Due to the nature of the condition, the program should be designed with an emphasis on ensuring the client's safety. (See "Safety Concerns for Clients With Osteoporosis" at the end of this article.)
Resistance TrainingIt is especially important that clients with confirmed or suspected osteoporosis have physician clearance before beginning any resistance training program. For safety reasons, it is always best to progress slowly using light hand weights (one to five pounds) for the first month of the program. As a client's strength increases, you can progress to heavier weights if there is no pain in the muscle groups being worked. I would recommend eight to 12 repetitions in one to three sets, performed to near failure for clients with mild osteoporosis and to 50 to 70 percent of one repetition maximum for those with moderate to severe osteoporosis, depending on the client's comfort level. Resistance exercises should be performed two to three days a week.
Because some weight machines start at too high a resistance and are difficult to get in and out of, clients with confirmed, significant osteoporosis should instead use light hand weights or elastic bands during the early stages of the program, to avoid injury. After two to three months of training, these clients can usually progress to heavier bands or weights. Clients with advanced osteoporosis will require more time to adapt and should progress at an even slower rate than those with significant osteoporosis.
When designing an exercise program for clients with osteoporosis who exhibit no pain or have only mild to moderate kyphosis (as confirmed by their physician), target the back muscles by including shoulder retraction exercises and shoulder raises. Many older adults become round-shouldered as they age, and these exercises can help improve posture. They can also hypothetically "load" the vertebrae, potentially increasing or maintaining bone density. Make sure the movements are performed slowly and do not cause discomfort. Clients who do exhibit pain or have severe, confirmed kyphosis should avoid exercises that bring the scapulae closer together (e.g., shoulder retractions).
When designing a program for younger individuals (less than 50 years old) who do not have significant osteoporosis, you may want to include explosive-type exercises, such as progressive plyometrics or step aerobics, to improve bone density. Many experts have noted that bones must be stressed to a minimal threshold value to attain significant gains in bone mass (Frost 1997). If the stress threshold is not high enough, the potential for bone development is greatly reduced. One study found that exercises such as step aerobics significantly increased bone mineral density in healthy, sedentary women between the ages of 35 and 45 years (Heinonen 1996). However, one very important caveat is that the injury risk is higher when performing these types of exercises. Therefore, it is recommended that prior to performing these types of exercises, all clients with suspected or confirmed osteoporosis be asked to obtain physician clearance and sign a waiver that explains the risk of injury. It is also important to progress explosive-type exercises slowly and increase the complexity only as clients become more conditioned. This type of activity should be limited to two to three days a week because of high stress load and potential for injury. Monitor clients very closely to ensure there is no soreness or pain after each session.
Balance TrainingLoss in bone density, accompanied by a decrease in balance, increases the risk of dangerous falls for those with osteoporosis. Therefore, balance training should be an integral part of any exercise program for these clients. When designing a program, add balance activities to the warm-up and cool-down. Here are a few examples:
- Have clients sit on a stability ball and lightly bounce for one to two minutes. Clients with especially poor balance should place the ball between parallel bars or hold onto the handle of a door while performing this activity.
- Have clients stand on one leg for several seconds during class time, then alternate legs. This should be done near a wall, chair or ballet barre so clients have something to grab if they lose their balance.
- Use a mirror to work on good postural balance, Clients with mild kyphosis often don't realize they are beginning to stoop. Standing erect improves posture and also places extra load on the spine, which can help slow the rate of bone loss.
- Have clients walk along a flat balance beam or a line on the floor. Instead of looking down at their feet while walking, they should look straight ahead and maintain an erect posture. If the clients have a high risk of falling, place the balance beam between parallel bars.
Flexibility training is safe for most clients with osteoporosis. Although flexibility training does not place a high enough load on bone to improve bone mass, this type of training is crucial for improving posture, relieving tightness and maintaining good mobility. However, avoid stretching exercises when working with clients who are experiencing pain in areas prone to fracture (e.g., hip, spine or wrist).
Clients with osteoporosis often become very inflexible in the chest and neck muscles as a result of their stooped posture. Exercises that "open" the chest by retracting the scapulae (shoulders) can help improve this inflexibility. It is also important to include exercises that stretch the hip flexors, since these muscles become tight in older adults from sitting for long periods and walking with a stooped posture.
Cardiovascular TrainingAlthough most of the research on exercise and osteoporosis indicates that resistance training results in the greatest improvements in bone density, older clients with this condition often become deconditioned from lack of activity. This deconditioned state typically leads to further disease and disability.
If clients are in the advanced stages of osteoporosis, it is best to perform cardiovascular exercises from a seated position for at least part of the exercise session. The recumbent stepper is especially useful since it allows frail clients to safely move their arms and legs simultaneously in a seated position. Many older adults prefer this machine over a stationary bike or treadmill because the recumbent stepper is relatively easy to use and has a large, comfortable seat.
Older clients with osteoporosis may have difficulty performing repetitive exercises using the same muscle groups for extended periods of time. Therefore, circuit training programs that require short periods of work using various muscle groups are recommended. (See "Sample Circuit Training Program" at the end of this article for an example.)
Interval training activities in which brief periods of work alternate with rest intervals may also be beneficial for deconditioned clients with confirmed, advanced osteoporosis. For example, alternating one-minute bouts of stationary bike riding with 30-second rest intervals can fatigue and help sustain longer periods of activity.
Other cardiovascular activities can be used to improve functional performance, provided the client does not experience pain or premature fatigue. Although swimming and pool exercises are excellent modalities for improving cardiovascular endurance, they are not recommended for improving bone density. Water is a non-gravity environment and does not place enough stress load on bone tissue to increase its mass (Bravo et al. 1997).
A Final WordFitness professionals who can develop safe exercise programs that improve bone health have a golden opportunity to impact the lives of the myriad older adults who suffer from osteoporosis. A general fitness program that focuses on resistance training, balance, flexibility and cardiovascular endurance while ensuring the client's safety is essential for maintaining or modestly improving bone mineral content.
The Principles of Wolff's Law- The more stress is placed on a bone, the stronger it gets.
- Weight-bearing exercise increases bone density and strength.
- Reduced weight bearing, due to disuse or immobilization, leads to progressive thinning and eventual loss of bone tissue, resulting in osteoporosis.
- Always obtain a physician's consent before developing an exercise program for these clients. If possible, consult with the physician regarding specific resistance exercises for any sites where the client has experienced a fracture.
- Before developing any exercise program, get a complete medical history to determine other conditions or considerations that could affect movement.
- Obtain a waiver for clients interested in classes or sessions that include explosive-type exercises (e.g., a high-impact step class). Ensure that the waiver outlines the risk of incurring injury when performing these types of exercise.
- Avoid jarring and high-load exercises when working with clients with advanced osteoporosis.
- Unless approved by a physician, avoid back exercises if clients have localized pain or show signs of severe kyphosis.
- Ensure that clients who have a high risk of falling always have something to grab onto (e.g., a ballet barre, parallel bars or a chair) when performing standing exercises.
- Reevaluate the exercise program if, during or after the session, the client shows any signs of pain or fatigue in vulnerable areas, such as the spine, hips and wrists.
Station 2 Use recumbent stepper for 4 min.
Station 3 Step on and off a 6" high step or platform for 2 min.
Station 4 Use upper-arm ergometer for 3 min.
Station 5 Sit in office chair with wheels and wheel across floor for 2 min.
Total Exercise Time: 15 min
Rest Intervals 1 min between each circuit (or longer if necessary)
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James H, Rimmer. PhD, is associate professor of human development and director of the Center on Health Promotion Research for Persons With Disabilities at the University of Illinois in Chicago. He is presently involved in two federally funded health promotion projects, one for the Centers for Disease Control and Prevention, and the other for the National Institute on Aging. Dr. Rimmer serves on IDEA's exercise and aging committee and is a scientific advisory board member for Life Fitness.
ReferencesAllen, J. 1999a. "Disease Isn't Limited to White Women." Los Angeles Times Health Section: S-5, February 22.
Allen, J. 1999b. "A Feeling Deep in Your Bones." Los Angeles Times Health Section: S-1, February 22.
Bravo, G., et al. 1997. "A Weight-Bearing, Water-Based Exercise Program for Osteopenic Women: Its Impact on Bone, Functional Fitness and Well-Being." Archives of Physical Medicine and Rehabilitation 78:1375-80.
Frost, H. M. 1997. "Why Do Marathon Runners Have Less Bone Than Weight Lifters? A Vital-Biomechanical View and Explanation." Bone 20:183-9.
Heinonen, A. 1996. "Randomised Controlled Trial and Effect of High-Impact Exercise on Selected Risk Factors for Osteoporotic Fractures." Lancet 348:1343-7.
Kanis, J. A., et al. 1994. "The Diagnosis of Osteoporosis." Journal of Bone Research 9:1137-41.
Kaplan, F. S. 1995. "Prevention and Management of Osteoporosis." Clinical Symposia 47:1-32.
Katz, W. A., & C. Sherman. 1998. "Osteoporosis: The Role of Exercise in Optimal Management." The Physician and Sportsmedicine 26:33-41.
Layne, J. E., & M. E. Nelson. 1999. "The Effects of Progressive Resistance Training on Bone Density: A Review." Medicine & Science in Sports & Exercise 31:25-30.
National Osteoporosis Foundation (NOF). 1999. Information Packet. (800) 223-9994.
Sato, M., et al. 1999. "Emerging Therapies for the Prevention and Treatment of Postmenopansal Osteoporosis." Journal of Medicinal Chemistry 42:1-24.
ResourcesFor more information on osteoporosis, contact the following offices:
National Institutes of Health (NIH) Osteoporosis and Related Bone Diseases National Resource Center (800) 624-2663, www.osteo.org
International Osteoporosis Foundation 33 (0) 472-117-472, www.effo.org
National Osteoporosis Foundation (800) 223-9994, www.nof.org
National Information Center on Physical Activity and Disability (312) 355-1400
