Weight-bearing exercise training and lumbar bone mineral content in postmenopausal women.
OBJECTIVE
To assess the effect of weight-bearing exercise training and subsequent detraining on lumbar bone mineral content in postmenopausal women.


METHODS
Non-randomized, controlled, short-term (9 months) trial and long-term (22 months) exercise training and detraining (13 months).


METHODS
Section of applied physiology at a university school of medicine.


METHODS
Thirty-five healthy, sedentary postmenopausal women, 55 to 70 years old. All women completed the study. There was 90% compliance with exercise training.


METHODS
All women were given calcium, 1500 mg daily. The exercise group did weight-bearing exercise (walking, jogging, stair climbing) at 70% to 90% of maximal oxygen uptake capacity for 50 to 60 min, 3 times weekly.


RESULTS
Bone mineral content increased 5.2% (95% confidence interval [CI], 2.0% to 8.4%; P = 0.0037) above baseline after short-term training whereas there was no change (-1.4%) in the control group. After 22 months of exercise, bone mineral content was 6.1% (95% CI, 3.9% to 8.3% above baseline; P = 0.0001) in the long-term training group. After 13 months of decreased activity, bone mass was 1.1% above baseline in the detraining group.


CONCLUSIONS
Weight-bearing exercise led to significant increases above baseline in bone mineral content which were maintained with continued training in older, postmenopausal women. With reduced weight-bearing exercise, bone mass reverted to baseline levels. Further studies are needed to determine the threshold exercise prescription that will produce significant increases in bone mass.
Dalsky
G P
GP
Washington University School of Medicine, St. Louis, Missouri.
Stocke
K S
KS
Ehsani
A A
AA
Slatopolsky
E
E
Lee
W C
WC
Birge
S J
SJ
D000368:Aged; D002136:Calcium, Dietary / Q000008:administration & dosage; D002135:Calcium-Binding Proteins / Q000097:blood; D005080:Exercise Test; D005260:Female; D006801:Humans; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000378:metabolism*; D008875:Middle Aged; D008903:Minerals / Q000378:metabolism*; D015675:Osteocalcin; D010024:Osteoporosis / Q000517:prevention & control*; D010806:Physical Education and Training; D011877:Radionuclide Imaging; D013997:Time Factors
D002136:Calcium, Dietary; D002135:Calcium-Binding Proteins; D008903:Minerals; D015675:Osteocalcin