Effect of changes in weight-bearing exercise on lumbar bone mass after age fifty.
This two year longitudinal study of 40 healthy subjects over age fifty (27 exercisers, 13 non-exercisers) was designed to evaluate the impact of weight-bearing exercise on lumbar bone mineral density as assessed by quantitative computed tomography. In both males and females exercising at moderate levels, a high correlation was found between changes in exercise and changes in bone density (r = 0.78 and 0.91, respectively P less than 0.002). For extreme levels of exercise (greater than 300 min/week in females over age fifty, and greater than 200 min/week in males over age seventy) bone density was low, confirming earlier cross-sectional results. Subjects without change in their exercise levels and non-exercisers lost similar amounts of bone. Increasing body mass index was identified as a protective factor with regard to lumbar bone loss. We conclude that in exercisers continuation of weight-bearing exercise is mandatory to prevent excessive bone loss. Extreme levels of exercise may be detrimental to bone density in subjects over age fifty years.
Department of Rheumatology, University Hospital, Zürich, Switzerland.
B A
BA
Michel
N E
NE
Lane
D A
DA
Bloch
H H
HH
Jones
J F
JF
Fries
D015519:Bone Density / Q000502:physiology*; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D010024:Osteoporosis / Q000453:epidemiology*; D015663:Osteoporosis, Postmenopausal / Q000453:epidemiology*; D012044:Regression Analysis; D012420:Running; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D016474:Weight-Bearing / Q000502:physiology