ORIGINAL ARTICLES   

The Journal of Sports Medicine and Physical Fitness 1999 September;39(3):226-32

Copyright © 2000 EDIZIONI MINERVA MEDICA

language: English

Exercise-induced muscle damage: absence of adaptive effect after a single session of eccentric isokinetic heavy resistance exercise

Prou E. ^{1, 2}, Guevel A. ¹, Benezet P. ², Marini J. F. ¹

¹ Faculté des Science du Sport, Université de Nice Sophia Antipolis (UNSA), Nice, France; ² Centre de Réadaptation Fonctionnelle de Valmante, Marseille, France

Backgrond. Unaccustomed eccen­tric exer­cise induc­es mus­cle dam­age. A sin­gle ses­sion of eccen­tric exer­cise can ­induce an “adap­tive ­effect” pro­tect­ing exer­cised mus­cles dur­ing sev­er­al ­weeks. Our aim was to ver­i­fy ­this phe­nom­e­non in iso­ki­net­ic exer­cise. Tested hypoth­e­sis was: the pro­gres­sive mus­cle ­rise in ten­sion due to iso­ki­net­ic eccen­tric ­actions ­would be insuf­fi­cient to ­induce the adap­tive ­effect.
Methods. Experimental ­design: pros­pec­tive ­study. Setting: gen­er­al com­mu­nity. Participants: six ­healthy and mod­er­ate­ly ­active (­untrained) ­males (29.1 yr±1.5 SEM). Interventions: sub­jects per­formed two iso­ki­net­ic eccen­tric exer­cis­es (EE1 and EE2) of the quad­ri­ceps fem­or­is of ­both ­legs (120°.s-1; 8 ­sets of 15 rep­e­ti­tions) sep­ar­at­ed by 4 ­weeks. Measures: ­type I ser­um myo­sin ­heavy ­chains (MHC) and crea­tine ­kinase con­cen­tra­tions (CK), and ­rate of per­ceived sore­ness (­DOMS) ­were col­lect­ed ­before ­each exer­cise and on ­days 1, 2, 4, 6 and 9.
Results. Both exer­cis­es ­induced sig­nif­i­cant (p<0.01) increas­es in MHC and CK con­cen­tra­tions, and ­DOMS ­score. There was no sig­nif­i­cant dif­fer­ence ­between EE1 and EE2, at any meas­ure­ment ­time for any param­e­ter. Mean ­peak val­ues (SEM) ­were respec­tive­ly (EE1; EE2): MHC (µU.l-1): 308 (192); 285 (191). CK (U.l-1): 1217 (760); 1297 (1039). ­DOMS ­score: 2.67 (0.52); 2.33 (0.52).
Conclusions. The ­first ses­sion of eccen­tric iso­ki­net­ic exer­cise (EE1) had no adap­tive ­effect ­against mus­cle dam­age ­when an iden­ti­cal ses­sion was per­formed 4 ­weeks lat­er (EE2). Muscle adap­ta­tion ­could ­have result­ed in ­increased ­work pro­duc­tion (+10.2%; p<0.05; ­from EE1 to EE2).