Strict adherence to a program of simple exercises walking, jogging, climbing stairs increased bone mass in 15 of 17 postmenopausal women participating in a study.
This new evidence, though preliminary, is the first substantial indication that exercise may be a treatment for low bone mass, a condition that is characteristic of osteoporosis, often referred to as "brittle bone disease." The key to rebuilding bones through exercise is achieving the proper training level and then continuing to exercise. For some of women, they like combining music from their best headphones for exercise along practicing time.
The study shows not only those women who exercise can increase bone mass in the spine, but, equally important, that if they stop exercising they lose the benefits bone mass returns to its original levels. Experts found that lumbar bone mineral content increased significantly after just nine months of weight-bearing exercise," said by an exercise physiologist. "The exercise must be consistent, though if it's sporadic or seasonal, you're unlikely to see an increase. With continued training, you maintain bone mass; but with inactivity, you lose the training effect."
After nine months of training, 15 of the exercisers had an average increase in bone mass of 5.2 percent, Dalsky reports. By 22 months, 10 of the 11 women still exercising had added more bone mass for a total increase of 6.1 percent. About a year after the exercisers stopped, Dalsky re-evaluated them and found that their lumbar bone mineral content had reverted to pre-exercise levels.
Exercise is not a substitute for two currently popular treatments, calcium supplements and among postmenopausal women estrogen combined with calcium supplements, Dalsky stresses. Women who are under physicians' orders to take either supplement should not stop simply because they have begun an exercise program, she says. Exercise may, however, enhance any benefits that calcium and estrogen have on bone mass, she adds.
Dr. Dalsky's study shows that when it comes to increasing bone levels, exercise is more effective than calcium and estrogen. The effectiveness of calcium alone in either maintaining or increasing bone mass has not been proven. Estrogen (replacement hormones that are a treatment for menopause) has been shown to maintain but not increase bone mass; its benefits depend on the individual's bone measurements when she begins the treatment, and last for as long as she takes the estrogen.
Most studies have measured appendicular bone generally the wrist or heel rather than the more critical measurement, axial bone, which is found in the spine and hip.
Appendicular tests can be deceiving, Dalsky says, because appendicular bone mass does not necessarily reflect the status of the axial skeleton. In addition, changes in response to therapy, for example, may be measured in the axial skeleton but not in the wrist. And for post-menopausal osteoporosis, spinal bone is the most important measure: It is more sensitive to loss of estrogen, and it is the site of vertebral fractures. Axial bone is measured by an x-ray type process called dual photon absorptiometry, which measures bone mineral content at parts of the body that are covered by tissue.
Dalsky began her study with all 35 participants were in good health, non-smokers (except one), at least five years past menopause, and on no medications, except estrogen that would affect calcium or bone levels. Seven had been on estrogen replacement therapy for at least five years. Seventeen women volunteered for the exercise group and 18 served as controls.
Calcium balance was assessed at the initial screening and after three, six, and nine months of participation in the study. Volunteers, who kept daily records of calcium intake, got about 60 percent of their 1500 milligrams from a calcium carbonate supplement and the remainder from calcium-rich foods.
The exercising participants were asked to attend three sessions a week, each consisting of 50 to 60 minutes of weight-bearing activities walking, jogging, treadmill-walking and stair-climbing. The women began exercise training for 20 to 30 minutes, gradually increasing their workout to 50 to 60 minutes by three months. During the remaining six months, they exercised for the same length of time but increased the intensity.
Whether exercise can help women who already have osteoporosis depends on the individual and what her bone mineral content is when she starts exercising, Dalsky says. There is no way, however, to reverse postural changes like "dowager's hump," which occurs when significant height is lost due to compressed or fractured vertebrae. At that point, the most that can be done is try to prevent further fractures.
She recommends exercise, but with limitations. For a woman who already has osteoporosis, the first concern is to avoid further fractures, so she should be well enough physically to exercise without injury. Get a physician's checkup for anyone 40 or older starting an exercise program, and particularly for women who are increasing calcium intake on their own. For women who know they have osteoporosis, she recommends an additional musculoskeletal evaluation by an exercise-oriented physical therapist.
How much should women exercise? "We don't know," Dalsky says. "All of our participants were normal, healthy women. Some had very low bone mass, but none had had major fractures, so they could exercise without any problem."
But some researchers warn that very slender women who exercise heavily may be more prone to osteoporosis. A tough multi-mile running schedule or any other sustained aerobic exercise can do more harm than good. The key consideration is premature cessation of menstruation, which is known as amenorrhea. This is often due to ultra-heavy exercise and is something to avoid if you wish to avoid osteoporosis.
Dr. Christopher Cann notes that amenorrheic women with little fat, such as women who perform large amounts of aerobic exercise, are known to lack normal concentrations of estrone, the female sex hormone. So the key is moderation.
If the woman is motivated, she may not need to be part a of closely supervised exercise program to get results, Dalsky notes. Most women can begin walking, for example, progressively increasing so that within three to four months they can cover three miles a day, four or five days a week.
"Use common sense. When something hurts, don't do it so hard. When you've been sick or traveling, don't step back into the program on the same level you were on before you left it."
Bone density tests, which can range up to $600, are unnecessary, she says, unless a woman runs a high risk for the disease. Thin, Caucasian women who have a family history of osteoporosis are at risk, especially in combination with such lifestyle factors as smoking, low calcium intake, high caffeine and alcohol intake, low activity level, early menopause or ovarian removal.
In addition, Dalsky advises any woman who changes her calcium intake to ask her physician for tests to monitor her response.
Exercising is one way to change lifestyle that younger women should consider, she says, but not necessarily just to prevent osteoporosis. "It positively affects health in so many other ways, and there are very few negative effects. We don't know right now if exercise can help young women improve bone density, but they'll get all the other benefits, plus they'll be forming a habit that may help later."
This new evidence, though preliminary, is the first substantial indication that exercise may be a treatment for low bone mass, a condition that is characteristic of osteoporosis, often referred to as "brittle bone disease." The key to rebuilding bones through exercise is achieving the proper training level and then continuing to exercise. For some of women, they like combining music from their best headphones for exercise along practicing time.
The study shows not only those women who exercise can increase bone mass in the spine, but, equally important, that if they stop exercising they lose the benefits bone mass returns to its original levels. Experts found that lumbar bone mineral content increased significantly after just nine months of weight-bearing exercise," said by an exercise physiologist. "The exercise must be consistent, though if it's sporadic or seasonal, you're unlikely to see an increase. With continued training, you maintain bone mass; but with inactivity, you lose the training effect."
- Bone mass the mineral content, plus the structure of bone gives bone strength, or resistance to fracture. A loss in bone mass weakens the bone because there are less minerals, and because the structure has changed.
- It's similar to a building with steel girders. The strength of the building comes from that framework if you take out a girder, the building is weaker, not only because there's less steel, but also because you've changed the structure.
- Osteoporosis is a progressive disease, mainly affecting older women, where substantial bone loss may result in painful and crippling fractures. Physiologists have determined that, at the point of fracture, women with osteoporosis have a bone mass that is 30 percent below the average of a young, normal woman. Bone loss may begin as early as age 25.
A Measurable Increase in Bone Mass
The Washington University Study measured the effects of weight-bearing exercise on lumbar (spinal) bone mass in 35 sedentary postmenopausal women, half of whom underwent exercise training from 9 to 22 months. All maintained a calcium intake of about 1500 milligrams a day throughout the study. The women, aged 55-70, were generally healthy, although their bone mass ranged between 75 to 85 percent of a normal, healthy 30-year-old.After nine months of training, 15 of the exercisers had an average increase in bone mass of 5.2 percent, Dalsky reports. By 22 months, 10 of the 11 women still exercising had added more bone mass for a total increase of 6.1 percent. About a year after the exercisers stopped, Dalsky re-evaluated them and found that their lumbar bone mineral content had reverted to pre-exercise levels.
Exercise is not a substitute for two currently popular treatments, calcium supplements and among postmenopausal women estrogen combined with calcium supplements, Dalsky stresses. Women who are under physicians' orders to take either supplement should not stop simply because they have begun an exercise program, she says. Exercise may, however, enhance any benefits that calcium and estrogen have on bone mass, she adds.
Dr. Dalsky's study shows that when it comes to increasing bone levels, exercise is more effective than calcium and estrogen. The effectiveness of calcium alone in either maintaining or increasing bone mass has not been proven. Estrogen (replacement hormones that are a treatment for menopause) has been shown to maintain but not increase bone mass; its benefits depend on the individual's bone measurements when she begins the treatment, and last for as long as she takes the estrogen.
Spine and Hip Strength Most Critical
Previous studies on exercise and bone mass have generally shown maintenance or a slowing of the rate of bone loss, but have not shown a true increase above baseline, Dalsky notes. "The question, really, is can you increase bone mineral content in a person compared to her initial levels?"Most studies have measured appendicular bone generally the wrist or heel rather than the more critical measurement, axial bone, which is found in the spine and hip.
Appendicular tests can be deceiving, Dalsky says, because appendicular bone mass does not necessarily reflect the status of the axial skeleton. In addition, changes in response to therapy, for example, may be measured in the axial skeleton but not in the wrist. And for post-menopausal osteoporosis, spinal bone is the most important measure: It is more sensitive to loss of estrogen, and it is the site of vertebral fractures. Axial bone is measured by an x-ray type process called dual photon absorptiometry, which measures bone mineral content at parts of the body that are covered by tissue.
Dalsky began her study with all 35 participants were in good health, non-smokers (except one), at least five years past menopause, and on no medications, except estrogen that would affect calcium or bone levels. Seven had been on estrogen replacement therapy for at least five years. Seventeen women volunteered for the exercise group and 18 served as controls.
Calcium balance was assessed at the initial screening and after three, six, and nine months of participation in the study. Volunteers, who kept daily records of calcium intake, got about 60 percent of their 1500 milligrams from a calcium carbonate supplement and the remainder from calcium-rich foods.
The exercising participants were asked to attend three sessions a week, each consisting of 50 to 60 minutes of weight-bearing activities walking, jogging, treadmill-walking and stair-climbing. The women began exercise training for 20 to 30 minutes, gradually increasing their workout to 50 to 60 minutes by three months. During the remaining six months, they exercised for the same length of time but increased the intensity.
Exercise Recommendations For Women With Osteoporosis
If a woman already has osteoporosis, how much can exercise help? It's too early to tell, the report says. "Theoretically, if we can increase bone mass and keep it above the fracture threshold, we should be able to reduce the incidence of future fracture," she comments. "But we don't have any data on that." Dalsky expects that bones would keep getting stronger with continued exercise, but rates of improvement would probably slow down.Whether exercise can help women who already have osteoporosis depends on the individual and what her bone mineral content is when she starts exercising, Dalsky says. There is no way, however, to reverse postural changes like "dowager's hump," which occurs when significant height is lost due to compressed or fractured vertebrae. At that point, the most that can be done is try to prevent further fractures.
She recommends exercise, but with limitations. For a woman who already has osteoporosis, the first concern is to avoid further fractures, so she should be well enough physically to exercise without injury. Get a physician's checkup for anyone 40 or older starting an exercise program, and particularly for women who are increasing calcium intake on their own. For women who know they have osteoporosis, she recommends an additional musculoskeletal evaluation by an exercise-oriented physical therapist.
How much should women exercise? "We don't know," Dalsky says. "All of our participants were normal, healthy women. Some had very low bone mass, but none had had major fractures, so they could exercise without any problem."
But some researchers warn that very slender women who exercise heavily may be more prone to osteoporosis. A tough multi-mile running schedule or any other sustained aerobic exercise can do more harm than good. The key consideration is premature cessation of menstruation, which is known as amenorrhea. This is often due to ultra-heavy exercise and is something to avoid if you wish to avoid osteoporosis.
Dr. Christopher Cann notes that amenorrheic women with little fat, such as women who perform large amounts of aerobic exercise, are known to lack normal concentrations of estrone, the female sex hormone. So the key is moderation.
Medical Tests, Supervised Exercise Not Always Necessary
Osteoporotic women may improve with less exercise initially. "Bone responds to stress. A woman who is already quite active needs much more stress to change her bone mass than a women who is relatively inactive because she's had a lot of fractures or is afraid of falling again."If the woman is motivated, she may not need to be part a of closely supervised exercise program to get results, Dalsky notes. Most women can begin walking, for example, progressively increasing so that within three to four months they can cover three miles a day, four or five days a week.
"Use common sense. When something hurts, don't do it so hard. When you've been sick or traveling, don't step back into the program on the same level you were on before you left it."
Bone density tests, which can range up to $600, are unnecessary, she says, unless a woman runs a high risk for the disease. Thin, Caucasian women who have a family history of osteoporosis are at risk, especially in combination with such lifestyle factors as smoking, low calcium intake, high caffeine and alcohol intake, low activity level, early menopause or ovarian removal.
In addition, Dalsky advises any woman who changes her calcium intake to ask her physician for tests to monitor her response.
Many Factors Affect Osteoporosis
Often people don't understand that, like heart disease, osteoporosis is a progressive, multifactorial, lifestyle-related disease. Concentrating on one factor such as calcium intake to prevent the disease would be the same as focusing on a lower cholesterol level to avoid heart disease. A conscientious change of lifestyle factors may help lower the risk of osteoporosis, but a large component heredity cannot be altered.Exercising is one way to change lifestyle that younger women should consider, she says, but not necessarily just to prevent osteoporosis. "It positively affects health in so many other ways, and there are very few negative effects. We don't know right now if exercise can help young women improve bone density, but they'll get all the other benefits, plus they'll be forming a habit that may help later."
