Document Detail

Structural and mechanical adaptations of immature trabecular bone to strenuous exercise.
MedLine Citation:
PMID:  2262448     Owner:  NLM     Status:  MEDLINE    
Effects of strenuous exercise on immature bone were examined in two clinically important regions, femoral neck (FN) and lumbar vertebra (L6). Female Sprague-Dawley rats (n = 20, 8 wk of age, 150-170 g) were exercised progressively 5 days/wk for approximately 1 h/day for 10 wk at 75-80% of maximum oxygen capacity on a motor-driven treadmill. Caged age-matched rats served as controls (n = 20). Rat FNs were tested in cantilever bending, and vertebral bodies were compressed to 50% of their initial height at a fast strain rate. In response to the strenuous exercise, the relative area of the FN trabecular core increased significantly at the expense of the cortical shell. With that structural change, the exercised FN had significantly less energy to proportional limit than controls. The FN material properties (normal stresses at proportional limit and maximum) were significantly diminished after 10 wk of strenuous exercise. At the same time, no differences were found in vertebral geometry or structural and material properties. In the immature rate, the differential responses of the FN vs. L6 may relate to load history rather than a general systemic response to the strenuous exercise.
J C Hou; G J Salem; R F Zernicke; R J Barnard
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Journal of applied physiology (Bethesda, Md. : 1985)     Volume:  69     ISSN:  8750-7587     ISO Abbreviation:  J. Appl. Physiol.     Publication Date:  1990 Oct 
Date Detail:
Created Date:  1991-02-01     Completed Date:  1991-02-01     Revised Date:  2013-09-26    
Medline Journal Info:
Nlm Unique ID:  8502536     Medline TA:  J Appl Physiol (1985)     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  1309-14     Citation Subset:  IM; S    
Department of Kinesiology, University of California, Los Angeles 90024-1568.
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MeSH Terms
Adaptation, Physiological
Bone and Bones / physiology*
Femur Neck / physiology
Lumbar Vertebrae / physiology
Oxygen Consumption
Physical Conditioning, Animal*
Rats, Inbred Strains
Grant Support

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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