CHANGES IN TISSUE DEGRADATION MARKERS AND SUBJECTIVE REPORTS OF PAIN RESULTING FROM ECCENTRIC MUSCLE CONTRACTIONS.

The delayed onset of muscular soreness (DOMS) following a heavy eccentric exercise was studied with the aim to verify the "muscular structure" and the "connective tissue" theories explaining the development of DOMS. Die responses of creatine kinase (CK; "structural theory" marker) and hydroxyproline (OHP; "connective tissue theory" marker), as well as level and location of the perceived soreness, were determined following eccentric exercise. Plasma CK activity was elevated 48 and 72 h after the acentric exercise compared with the pre-exercise values, while OHP concentrations remained unchanged. Examination of pain location reports revealed two groups of responders (distal vs. mid-point muscle pain). Distal pain responders were found to have significantly higher post-exercise CK activity than mid-point pain responders, the OHP levels being alike. These findings are supportive of the "muscular structure" theory for DOMS development. However, the non-uniform location for DOMS pain confounds the overall data interpretation.