title: Exercise-induced muscle damage, repair, and adaptation in humans.
abstract: This study examined exercise-induced muscle damage, repair, and rapid adaptation. Eight college-age women performed three eccentric exercises of the forearm flexors. One arm performed 70 maximal contractions (70-MAX condition), and the other arm performed 24 maximal contractions (24-MAX) followed 2 wk later by 70 maximal contractions (70-MAX2). Criterion measures of serum creatine kinase, muscle soreness and pain, isometric strength, and muscle shortening were assessed before, immediately after, and for 5 days after each exercise. Significant changes in all criterion measures were found after the 70-MAX exercise with a slow recovery that was not complete by day 5 after exercise. The 24-MAX condition showed only small changes in the criterion measures. Changes in the criterion measures after the 70-MAX2 exercise were significantly smaller than those after the 70-MAX exercise. Results from this study, with regard to the ability of the muscle to adapt to exercise-induced damage, suggest that an adaptation takes place such that the muscle is more resistant to damage and any damage that does occur is repaired at a faster rate. It is also clear that a relatively small insult will produce this adaptation.
authors.affiliation: Department of Exercise Science, University of Massachusetts, Amherst 01003.
authors.forename: P M
authors.initials: PM
authors.lastname: Clarkson
authors.forename: I
authors.initials: I
authors.lastname: Tremblay
mesh_terms: D000222:Adaptation, Physiological; D000328:Adult; D001132:Arm; D003402:Creatine Kinase / Q000097:blood; D005260:Female; D006801:Humans; D009119:Muscle Contraction; D009132:Muscles / Q000473:pathology / Q000502:physiology*; D009211:Myoglobin / Q000032:analysis; D010146:Pain; D005082:Physical Exertion; D013997:Time Factors
chemical_list: D009211:Myoglobin; D003402:Creatine Kinase