TY - JOUR
T1 - Associations of physical activity duration, frequency, and load with volumetric BMD, geometry, and bone strength in young girls
AU - Farr, J. N.
AU - Blew, R. M.
AU - Lee, V. R.
AU - Lohman, T. G.
AU - Going, S. B.
N1 - Funding Information:
We appreciate the participation and support of principals, teachers, parents, and students from the schools in the Catalina Foothills and Marana School Districts. We also wish to thank the radiation technicians, program coordinators, and all other members of the Jump-In Study team for their contribution. The project described was supported by Award Number HD-050775 (SG) from the National Institute of Child Health and Human Development. JF was supported by NIH NIGMS T32 GM-08400: Graduate Training in Systems and Interactive Physiology.
PY - 2011/5
Y1 - 2011/5
N2 - More efficacious physical activity (PA) prescriptions for optimal bone development are needed. This study showed that PA duration, frequency, and load were all independently associated with bone parameters in young girls. Increased PA duration, frequency, and load are all important osteogenic stimuli that should be incorporated into future PA interventions. Introduction: This study evaluated the associations of physical activity (PA) duration, frequency, load, and their interaction (total PA score=duration×frequency×load) with volumetric bone mineral density, geometry, and indices of bone strength in young girls. Methods: Four hundred sixty-five girls (aged 8-13 years) completed a past year physical activity questionnaire (PYPAQ) which inquires about the frequency (days per week) and duration (average minutes per session) of leisure-time PA and sports. Load (peak strain score) values were assigned to each activity based on ground reaction forces. Peripheral quantitative computed tomography was used to assess bone parameters at metaphyseal and diaphyseal sites of the femur and tibia of the non-dominant leg. Results: Correlations across all skeletal sites between PA duration, frequency, load and periosteal circumference (PC), bone strength index (BSI), and strength-strain index (SSI) were significant (≤0.05), although low (0.10-0.17). A 2.7-3.7% greater PC across all skeletal sites was associated with a high compared to a low PYPAQ score. Also, a high PYPAQ score was associated with greater BSI (6.5-8.7%) at metaphyseal sites and SSI (7.5-8.1%) at diaphyseal sites of the femur and tibia. The effect of a low PYPAQ score on bone geometric parameters and strength was greater than a high PYPAQ score. Conclusions: PA duration, frequency, and load were all associated with bone geometry and strength, although their independent influences were modest and site specific. Low levels of PA may compromise bone development whereas high levels have only a small benefit over more average levels.
AB - More efficacious physical activity (PA) prescriptions for optimal bone development are needed. This study showed that PA duration, frequency, and load were all independently associated with bone parameters in young girls. Increased PA duration, frequency, and load are all important osteogenic stimuli that should be incorporated into future PA interventions. Introduction: This study evaluated the associations of physical activity (PA) duration, frequency, load, and their interaction (total PA score=duration×frequency×load) with volumetric bone mineral density, geometry, and indices of bone strength in young girls. Methods: Four hundred sixty-five girls (aged 8-13 years) completed a past year physical activity questionnaire (PYPAQ) which inquires about the frequency (days per week) and duration (average minutes per session) of leisure-time PA and sports. Load (peak strain score) values were assigned to each activity based on ground reaction forces. Peripheral quantitative computed tomography was used to assess bone parameters at metaphyseal and diaphyseal sites of the femur and tibia of the non-dominant leg. Results: Correlations across all skeletal sites between PA duration, frequency, load and periosteal circumference (PC), bone strength index (BSI), and strength-strain index (SSI) were significant (≤0.05), although low (0.10-0.17). A 2.7-3.7% greater PC across all skeletal sites was associated with a high compared to a low PYPAQ score. Also, a high PYPAQ score was associated with greater BSI (6.5-8.7%) at metaphyseal sites and SSI (7.5-8.1%) at diaphyseal sites of the femur and tibia. The effect of a low PYPAQ score on bone geometric parameters and strength was greater than a high PYPAQ score. Conclusions: PA duration, frequency, and load were all associated with bone geometry and strength, although their independent influences were modest and site specific. Low levels of PA may compromise bone development whereas high levels have only a small benefit over more average levels.
KW - Bone geometry
KW - Exercise
KW - Female
KW - Peripheral quantitative computed tomography (pQCT)
KW - Youth
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U2 - 10.1007/s00198-010-1361-8
DO - 10.1007/s00198-010-1361-8
M3 - Article
C2 - 20694457
AN - SCOPUS:79955469426
SN - 0937-941X
VL - 22
SP - 1419
EP - 1430
JO - Osteoporosis International
JF - Osteoporosis International
IS - 5
ER -