The Tortoise Beats the Hare in the Race for Stronger Bones

Source: Tufts University
February 8, 2002 (Reviewed: February 22, 2004)

When it comes to bone-strengthening exercise, consistency rather than speed appears to be the key to success. According to a study recently published in the Journal of the American Geriatrics Society, faithful attention to a moderate exercise program can help preserve bone strength in older women.

U.S. researchers surveyed 63 postmenopausal women classified as sedentary (no regular exercise within the last 2 years); active (regular exercise at least 30 minutes a day for 3 days); and very active (longtime competitive athletes). About half of the women received hormone replacement therapy. All provided detailed diet and health information and had X-rays that measured bone mineral density of the total body, hip, and spine.

Steady exercise made a difference

Of the three groups, the women who exercised at least three times a week had the strongest bones, surpassing both the sedentary women and those who had spent years as competitive athletes. These results held even after accounting for factors known to affect bone health, such as diet and smoking. Of the regular exercisers, those on hormone replacement therapy showed even greater degrees of bone strength.

The results of this study underscore the point that regular exercise should be a high health priority, especially after the menopause. Women hit their peak bone mineral density at about age 30, and gradually decline in bone strength after that. Bone demineralization rapidly accelerates after the menopause, when women lose the protective effect of estrogen. Hormone replacement therapy slows this loss, but can't do the job alone -- both a diet rich in vitamin D and calcium and regular, weight-bearing exercise contribute to stronger bones.

Looking for long term benefits

The women who fared best in this study walked or did aerobics on a weekly schedule for an average of 12 years. This steady -- but not necessarily strenuous -- exercise over a period of years helped them counteract some of the bone-thinning effects of aging.

Who are these women? We've all seen them -- they're walking the mall before the stores open, they're putting miles in on the track or along the side of the road, dressed in rain gear when it's drizzling, parkas when it's cold, and reflectors at dawn and dusk. Most of them are as busy as the rest of us, but they've put exercise at the top of their 'to do' list. As the results of this study illustrate, they've made a wise choice.

Source

• Moderate physical activity is associated with higher bone mineral density in postmenopausal women. JM. Hagberg, JM. Zmuda, SD. McCole,  et al., J Am Geriatr Soc., 2001, vol. 49, pp. 1411--1417

Related Links
Can Action Each Day Keep Fractures Away?
Winning the Battle of the Bones?
Physical Activity in Women over 40: What Helps? What Hinders?
Exercise May Boost Immunity
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