Best bone building exercises: increasing the "load" on your bones can help maintain and even build bone mass.
When weight is put on bones during exercise, such as walking or strength-training, it stimulates the action of bone-building cells to help prevent too much bone from being broken down by the body, stabilizing bone mass.
German researchers reported that among early postmenopausal women with osteoporosis who were not being treated with medications, those who exercised four times a week had stable bone density; those who did not exercise lost bone.
However, a regimen of strength-training exercises that further increase the "load" on bones by adding weights can actually help build bone mineral density (BMD) in areas prone to fracture. And numerous studies find that older women who do exercises to aid balance, such as t'ai chi, can help prevent the falls that can lead to fracture.
AN EXERCISE PRESCRIPTION
There are actually two types of bone loss: age-related bone thinning that happens slowly in men and women, and the accelerated loss of bone mineral density that occurs in women as estrogen levels drop after menopause.
Age-related bone loss may be partly due to a decrease in physical activity in older people, observes Wendy M. Kohrt, Ph.D., professor of medicine at the University of Colorado Health Sciences Center. "If you can maintain a relatively high level of physical activity throughout your lifetime, you may be able to slow the rate of aging-related bone loss and, if not prevent, at least delay your risk for osteoporosis."
Dr. Kohrt was the lead author of a position statement on exercise and bone health from the American College of Sports Medicine (ACSM). The paper, published in Medicine & Science in Sports & Exercise, states that regular physical activity is the "only known intervention that can potentially strengthen bones and reduce the risk of falling in older people with osteoporosis."
The ACSM sets out specific exercise "prescriptions" for people at various ages and stages in life. The exercise prescription for adults to help preserve bone mass includes weight-bearing endurance activities such as tennis and jogging, activities that involve jumping, and resistance exercise (weight lifting) of moderate to high intensity. Weight-bearing activities should be done 3-5 times per week, and resistance exercise 2-3 times per week, 30-60 minutes a day of combined exercise.
"The key to strength-training is not to increase the number of repetitions but to progress over time to heavier weights," explains Miriam E. Nelson, Ph.D., director of the John Hancock Center for Physical Activity and Nutrition at Tufts University in Boston. "How heavy the weights you use depends on age and strength. For an 80-year-old woman, 5-8 pounds may be too heavy, but for a younger woman it may not be enough." In general, she says, women should lift a heavy enough weight that causes their muscles to become "fatigued" after 5-6 lifts. Start with lighter weights and work up slowly. It's helpful to have a trainer or other fitness professional show you how to use weights properly.
THE BEBT EXERCISES
A specific regimen of strength-training exercises, performed under supervision in a gym setting, can actually build bone mass in fracture-prone areas.
The Bone Estrogen Strength Training (BEST) study involved 320 sedentary but otherwise healthy post-menopausal women, aged 44 to 66, most of whom were osteopenic. The women were randomized to a regimen of strength-training exercises or a non-exercise group. The workout involved three sessions a week of supervised, progressive weight-training with exercises to strengthen the small and large-muscle groups supporting the spine and hip--key areas associated with osteoporotic fractures. All the participants were given twice-daily 800 mg calcium citrate supplements (Citracal); around half were taking estrogen. Scans were taken of the hip and spine before and after the one-year study period, and at follow-up four years later.
"After one year, there was an increase in bone density of around one percent at the hip and spine," says Timothy Lohman, Ph.D., professor in the department of physiology at the University of Arizona, who headed the study. "After four years, those women who continued to exercise maintained the gains in bone density, while those who did not exercise lost bone." The combination of calcium and exercise produced an increase in BMD in both the hip area of the upper thigh bone (femur) and lower (lumbar) spine, regardless of whether the women took estrogen. The more weight the women lifted, the greater the increase in BMD. Overall, the lower body strength of the women in the exercise group increased by 65 percent, and they gained 20-40 percent in upper body strength, Dr. Lohman adds.
Avoiding fractures also means avoiding falls. There are a number of easy balance exercises you can do at home, using just a sturdy chair or table to hold onto.
"Exercises such as heel-toe walking, walking on tiptoes, standing on one leg are very simple to do and don't require special equipment or training. But they provide remarkable benefits," observes Dr. Nelson. "Poor balance often relates to weakness. We have to help women become stronger. It's hard work, but there's so much you can do."
What you can do to maintain bone strength:
* Take 1,200-1,500 mg of calcium daily, with 600-800 IU of vitamin D.
* Do weight-bearing aerobic exercise at least three times a week to maintain BMD.
* Ask your doctor about starting strength-training to build bone.
* Have regular bone density scans as advised by your doctor.
THE "BEST" EXERCISES FOR BONES
The BEST bone health regimen focuses on building bone density in typically vulnerable areas of the spine and hip. The program is conducted only in a supervised gym setting three times a week In each session, there are 20-25 minutes of resistance training with two sets of 6-8 repetitions of six core exercises, plus 7-10 minutes of cardiovascular, weight-bearing activity, such as weighted walking, stair-climbing, and small-muscle-group exercises using stretch bands and physioballs.
The weights lifted are progressively increased, and the wall squat serves as an introduction to a weighted squat using a barbell, (Over the first year of the study, the weights lifted were increased 2-3 times.) Most gyms have equipment similar to that shown that can be used for the BEST regimen. Participants should be cleared by a physician, and have a certified fitness trainer or physical therapist instruct them in the proper form for the exercises, advises Lauve L Metcalfe, who trained the women in the BEST study. Information on the program and a professional instruction book, The BEST Exercise Program for Osteoporosis Prevention (2004, SSW Fitness), are available through the University of Arizona Center for Physical Activity and Nutrition: www.cpanarizona.org
One-arm military press: Develops strength for lifting items overhead, as well as shoulder shape and size. The exercise targets the bones of the spinal vertebrae and lower (lumbar) spine.
Wall squat: Strengthens and defines lower body, strengthens rear hip muscles and takes pressure off the lower back Squats target the thigh bone (femur), femoral neck (which connects the hip bone to the femur), the trochanter (top part of femur), spinal vertebrae, and lumbar spine.
Lat pull down: Develops strength in the muscles of the upper back in addition to the outer back muscles. Targets the bones of the spinal vertebrae and lumbar spine.
Back extension: Provides back stability, which lifts the torso into extension. Targets the spinal vertebrae and lumbar spine, and strengthens key muscles of the spine.
Leg press: Develops leg strength for walking, climbing, and running. Targets the thigh bone (femur) and femoral neck. Strengthens key leg and hip muscles needed for stability, the large thigh muscle (quadriceps), rear hip muscles (gluteals), and the large tendons at the back of the knee (hamstrings).
Seated row: Develops strong back muscles to assist in pulling actions and general torso stability;, which contributes to a strong posture (and flattering V-shaped torso). Targets the spinal vertebrae and lumbar spine. Strengthens the shoulders, arms, and important muscles that support the back
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|Publication:||Saturday Evening Post|
|Article Type:||Case study|
|Date:||Sep 1, 2007|
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