Avoiding osteoporosis with exercise. (enhancement of benefits from calcium and estrogen)

AVOIDING OSTEOPOROSIS WITH EXERCISE

EXERCISE MAY ENHANCE ANY BENEFITS THAT CALCIUM AND ESTROGEN HAVE ON BONE MASS

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 at Washington University School of Medicine in St. Louis.

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, notes principal investigator Gail Dalsky, Ph.D., who published her results in a recent issue of the Annals of Internal Medicine.

Her study shows not only that 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.

"We've found that lumbar bone mineral content increased significantly after just nine months of weight-bearing exercise," says Dalsky, 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…