Connective Tissue Breakdown and Bone Morphology Change Following Increased Intensity Exercise
Abstract
Two plasma indicators of connective tissue (CT) degradation have been identified in previous work. One of the these, hydroxyproline (OHP), is a widely accepted measure of CT turnover; the other, hydroxylysylpyridinoline (HP), has only recently been isolated in plasma. In this study, responses of OHP and HP are compared to bone morphology changes associated with a 9-week period of increased intensity aerobic exercise. Bone morphology was measured as tibial bone mineral density (BMD) from dual photon absorptiometry (DPA), and tibial cross-sectional area (XAREA) from quantitative computed tomography (QCT). Nine local club runners (TGRP: mean age 36.6 yrs, distance 22.9 km/wk, pace 3.30 m/ sec) ran their normal program for a 3-week baseline period. Their pace was increased 4% (distance unchanged) for a 9-week period. Ten university staff personnel whose training remained stable for 9 weeks served as controls. OHP, HP, BMD, and XAREA were measured prior to (T1) and following (T2) the 9-week period. Repeated measures ANOVA revealed significant group by time interactions for OHP (p=0.03), HP (P<0.001), and BMD (p=0.02). OHP and HP increased and BMD decreased significantly for the TGRP at T2. XAREA was unchanged. A modest, but significant, Spearman Correlation (-0.44, p=0.03) was found between residuals approached significance (-0.37, p=0.06). It was concluded that:1) bone mineral density adjustments to increased intensity were not complete after 9 weeks, 2) increased intensity exercise at a 4% rate does not alter tibial XAREA, and 3) HP appears to be a better indicator of connective tissue degradation tan is OHP
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1991
- Accession Number
- ADA280896
Entities
People
- A. C. Vailas
- B. Mandelbaum
- H. W. Gorth Jr.
- James A. Hodgdon
- M. Riedy
Organizations
- Naval Health Research Center