TY - JOUR
T1 - Effects of exercise involving predominantly either joint-reaction or ground-reaction forces on bone mineral density in older women
AU - Kohrt, Wendy M.
AU - Ehsani, Ali A.
AU - Birge, Stanley J.
PY - 1997/8
Y1 - 1997/8
N2 - This study compared the effects of two exercise training programs, 11 months in duration, on bone mineral density (BMD) in older, sedentary women. Thirty-nine women, aged 60-74 years, were assigned to the following groups: (a) a group that performed exercises that introduced stress to the skeleton through ground-reaction forces (GRF) (i.e., walking, jogging, stairs); (b) a group that performed exercises that introduced stress to the skeleton through joint-reaction forces (JRF) (i.e., weight lifting, rowing); or (c) a no- exercise control group. BMD of the whole body, lumbar spine, proximal femur, and distal forearm was assessed five times at ≃3-mouth intervals. The GRF and JRF exercise programs resulted in significant and similar increases in BMD of the whole body (2.0 ± 0.8% and 1.6 ± 0.4%, respectively), lumbar spine (1.8 ± 0.7% and 1.5 ± 0.5%, respectively), and Ward's triangle region of the proximal femur (6.1 ± 1.5% and 5.1 ± 2.1%, respectively). There was a significant increase in BMD of the femoral neck only in response to the GRF exercise program (GRF, 3.5 ± 0.8%; JRF, -0.2 ± 0.7%). There were no significant changes in BMD in control subjects. Among all exercisers, there was a significant inverse (r = -0.52, p < 0.01) relationship between increases in whole body BMD and reductions in fat mass, suggesting a dose response effect of exercise on bone mass. Although femoral neck BMD was responsive only to the GRF exercise program, some adaptations (i.e., increase in lean body mass and strength) that were specific to the JRF exercise program may he important in preventing osteoporotic fractures by reducing the risk for falls. It remains to he determined whether all of these benefits can be gained through a training program that combines the different types of exercises employed in this study.
AB - This study compared the effects of two exercise training programs, 11 months in duration, on bone mineral density (BMD) in older, sedentary women. Thirty-nine women, aged 60-74 years, were assigned to the following groups: (a) a group that performed exercises that introduced stress to the skeleton through ground-reaction forces (GRF) (i.e., walking, jogging, stairs); (b) a group that performed exercises that introduced stress to the skeleton through joint-reaction forces (JRF) (i.e., weight lifting, rowing); or (c) a no- exercise control group. BMD of the whole body, lumbar spine, proximal femur, and distal forearm was assessed five times at ≃3-mouth intervals. The GRF and JRF exercise programs resulted in significant and similar increases in BMD of the whole body (2.0 ± 0.8% and 1.6 ± 0.4%, respectively), lumbar spine (1.8 ± 0.7% and 1.5 ± 0.5%, respectively), and Ward's triangle region of the proximal femur (6.1 ± 1.5% and 5.1 ± 2.1%, respectively). There was a significant increase in BMD of the femoral neck only in response to the GRF exercise program (GRF, 3.5 ± 0.8%; JRF, -0.2 ± 0.7%). There were no significant changes in BMD in control subjects. Among all exercisers, there was a significant inverse (r = -0.52, p < 0.01) relationship between increases in whole body BMD and reductions in fat mass, suggesting a dose response effect of exercise on bone mass. Although femoral neck BMD was responsive only to the GRF exercise program, some adaptations (i.e., increase in lean body mass and strength) that were specific to the JRF exercise program may he important in preventing osteoporotic fractures by reducing the risk for falls. It remains to he determined whether all of these benefits can be gained through a training program that combines the different types of exercises employed in this study.
UR - http://www.scopus.com/inward/record.url?scp=0030806249&partnerID=8YFLogxK
U2 - 10.1359/jbmr.1997.12.8.1253
DO - 10.1359/jbmr.1997.12.8.1253
M3 - Article
C2 - 9258756
AN - SCOPUS:0030806249
VL - 12
SP - 1253
EP - 1261
JO - Journal of Bone and Mineral Research
JF - Journal of Bone and Mineral Research
SN - 0884-0431
IS - 8
ER -