Difference in the magnitude of muscle damage between elbow flexors and knee extensors eccentric exercises.

The aim of this study was to investigate the difference in the magnitude of muscle damage between maximal eccentric exercises of the elbow flexors (EF) and knee extensors (KE). Twelve sedentary male volunteers participated in the study. Range of motion (ROM), isometric peak torque (IPT), delayed onset of muscle soreness (DOMS), creatine kinase activity (CK), and myoglobin concentration (Mb) were evaluated before, immediately after, and on the 1(st) , 2(nd), 3(rd) , and 7(th) days following exercise. Total work (TW) during exercises was recorded and corrected by muscle volume (TWc). TWc was greater (p < 0.01) for EF [24 (2) joule·cm-3] than for KE [7 (0.4) joule·cm(-3)]. Increases in CK on the 2(nd) , 3(rd) , and 7(th) days (p < 0.01) and increases in Mb on the 1(st) , 2(nd) , 3(rd) , and 7(th) days were significantly (p<0.01) larger for EF than for KE. The decline in IPT was greater (p < 0.05- 0.01) for EF at all test occasions compared with KE. The results of this study demonstrate that the magnitude of muscle damage is greater and the recovery is slower following maximal eccentric exercise of the EF than of the KE for sedentary males. Key pointsThe magnitude of muscle damage is greater and the recovery is slower following maximal eccentric exercise of the EF than of the KE for sedentary males.This may be because of the higher total eccentric work per muscle unit in elbow flexors.