Susceptibility to Exercise-Induced Muscle Damage: a Cluster Analysis with a Large Sample.
We investigated the responses of indirect markers of exercise-induced muscle damage (EIMD) among a large number of young men (N=286) stratified in clusters based on the largest decrease in maximal voluntary contraction torque (MVC) after an unaccustomed maximal eccentric exercise bout of the elbow flexors. Changes in MVC, muscle soreness (SOR), creatine kinase (CK) activity, range of motion (ROM) and upper-arm circumference (CIR) before and for several days after exercise were compared between 3 clusters established based on MVC decrease (low, moderate, and high responders; LR, MR and HR). Participants were allocated to LR (n=61), MR (n=152) and HR (n=73) clusters, which depicted significantly different cluster centers of 82%, 61% and 42% of baseline MVC, respectively. Once stratified by MVC decrease, all muscle damage markers were significantly different between clusters following the same pattern: small changes for LR, larger changes for MR, and the largest changes for HR. Stratification of individuals based on the magnitude of MVC decrease post-exercise greatly increases the precision in estimating changes in EIMD by proxy markers such as SOR, CK activity, ROM and CIR. This indicates that the most commonly used markers are valid and MVC orchestrates their responses, consolidating the role of MVC as the best EIMD indirect marker.
School of Physical Education and Sport, University of São Paulo, São Paulo, Brazil.
F
F
Damas
Biomedical and Health Sciences, School of Exercise, Edith Cowan University, Joondalup, Australia.
K
K
Nosaka
Department of Physical Education, Federal University of São Carlos - UFSCar, São Carlos, Brazil.
C A
CA
Libardi
Department of Physical Education, National Taiwan Normail University, Taipei City, Taiwan.
T C
TC
Chen
School of Physical Education and Sport, University of São Paulo, São Paulo, Brazil.
C
C
Ugrinowitsch
D000328:Adult; D016000:Cluster Analysis; D003402:Creatine Kinase / Q000097:blood; D004551:Elbow Joint / Q000502:physiology; D015444:Exercise; D006801:Humans; D008297:Male; D009119:Muscle Contraction; D018482:Muscle, Skeletal / Q000293:injuries* / Q000502:physiology; D063806:Myalgia; D016059:Range of Motion, Articular; D012189:Retrospective Studies; D019415:Torque; D055815:Young Adult
D003402:Creatine Kinase