RT Journal A1 Michel BA, Bloch DA, Fries JF T1 WEight-bearing exercise, overexercise, and lumbar bone density over age 50 years JF Archives of Internal Medicine JO Archives of Internal Medicine YR 1989 FD October 1 VO 149 IS 10 SP 2325 OP 2329 DO 10.1001/archinte.1989.00390100127027 UL http://dx.doi.org/10.1001/archinte.1989.00390100127027 AB • This cross-sectional study of 78 healthy subjects older than age 50 years was designed to examine the association between weight-bearing exercise and lumbar bone mineral content as assessed by quantitative computed tomography. In women, a strong correlation existed between bone density and the amount of exercise for up to 300 min/wk. However, 5 of 28 women exercising 300 min/wk or more had surprisingly low bone density, not explained by other factors. In 50 men, we also found a strong positive correlation between exercise and bone density for those up to age 65 years. Over age 65, 3 men had low bone density despite extremely vigorous exercise. We conclude that moderate weight-bearing exercise may increase lumbar bone density, but we raise the hypothesis that extremely vigorous exercise actually may be detrimental to bone density in individuals after age 50.(Arch Intern Med. 1989;149:2325-2329)