Creatine kinase and muscle soreness after repeated isometric exercise.
Journal Article
Overview
abstract
This study examined adaptation to isometric exercise with regard to changes in serum creatine kinase (CK) activity and muscle soreness. Forty-five college-age males were placed into six groups, each performing two bouts of strenuous isometric exercise of the knee extensors. In experiment 1 (N = 27), after performing the first bout of exercise, groups A, B, and C performed the second bout 3, 6, and 9 wk later, respectively. In experiment 2 (N = 18), groups D, E, and F performed the second exercise bout 1, 2, and 3 wk after the first bout, respectively. In experiment 3, group D performed two additional exercise bouts; thus, this group performed a total of four bouts spaced 1 wk apart. Muscle soreness and CK were assessed prior to and 6, 18, and 24 (or 42) h following each exercise. In experiment 1, no significant difference in soreness or serum CK was found between bouts 1 and 2. In experiment 2, a significant decrease in the CK and soreness responses was found on bout 2 compared with bout 1 (P less than 0.05). In experiment 3, serum CK and soreness responses were highest following bout 1 while bouts 2, 3, and 4 were not significantly different from one another. Performance of this isometric exercise results in an adaptation that lasts approximately 3 wk, with the greatest adaptation occurring after one bout.
