TY - JOUR
T1 - Susceptibility to Exercise-Induced Muscle Damage
T2 - A Cluster Analysis with a Large Sample
AU - Damas, F.
AU - Nosaka, K.
AU - Libardi, C. A.
AU - Chen, T. C.
AU - Ugrinowitsch, C.
N1 - Funding Information:
We would like to acknowledge the participants included in this study. In addition, we would like to acknowledge Felipe Cassaro Vechin, Ricardo Berton, Manoel Lixandrao and Arthur Gaspari that helped with the discussion of the ideas of this manuscript. This work was supported by Sao Paulo Research Foundation (FAPESP) grants #2013/21218-4 to C.A.L and grants #2012/24499-1 and #2014/19594-0 to F.D. CU is supported by CNPq grant #304205/2011-7.
PY - 2016/7/1
Y1 - 2016/7/1
N2 - 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.
AB - 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.
KW - creatine kinase
KW - elbow flexors
KW - isometric contraction
KW - lengthening contractions
KW - muscle soreness
KW - range of motion
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U2 - 10.1055/s-0042-100281
DO - 10.1055/s-0042-100281
M3 - Article
C2 - 27116346
AN - SCOPUS:84965054515
SN - 0172-4622
VL - 37
SP - 633
EP - 640
JO - International Journal of Sports Medicine
JF - International Journal of Sports Medicine
IS - 8
ER -