Relations between muscle soreness and biochemical and functional outcomes of eccentric exercise.

Correlations between functional and biochemical outcomes of eccentric exercise and between these outcomes and "delayed-onset muscle soreness" (DOMS) were studied. Maximal isotonic force, extension and flexion angle of the elbow, creatine kinase activity, and myoglobin concentration in serum were measured in 27 male subjects during 5 days after 120 maximal eccentric contractions of the forearm flexors. Significant correlations were found between values at 1 to 96 h after exercise for force (r = 0.55 to 0.96), flexion (0.52 to 0.94), extension (0.41 to 0.95), and myoglobin (0.55 to 0.97) and at 24 to 96 h for creatine kinase (0.67 to 0.96) and DOMS (0.45 to 0.72). Clusters of significant correlations (0.32 to 0.91) were found among all functional and biochemical measures. DOMS, however, showed only few and lower correlations with the other parameters (0.34 to 0.63). These results can practically be interpreted as follows: 1) subjects need more time to recover completely when early deviations after eccentric exercise are large, 2) a large change in one measure is accompanied by large deviations in other measures, and 3) objective outcomes of eccentric exercise are more accurate parameters than a DOMS score for use in effect studies.