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Concentric or eccentric training effect on eccentric exercise-induced muscle damage

2002; Lippincott Williams & Wilkins; Volume: 34; Issue: 1 Linguagem: Inglês

10.1097/00005768-200201000-00011

1530-0315

Kazunori Nosaka, Mike Newton,

Sports Performance and Training

NOSAKA, K., and M. NEWTON. Concentric or eccentric training effect on eccentric exercise-induced muscle damage. Med. Sci. Sports Exerc., Vol. 34, No. 1, 2002, pp. 63–69. Purpose The purpose of this study was to compare changes in muscle damage indicators following 24 maximal eccentric actions of the elbow flexors (Max-ECC) between the arms that had been previously trained either eccentrically or concentrically for 8 wk. Methods Fifteen subjects performed three sets of 10 repetitions of eccentric training (ECC-T) with one arm and concentric training (CON-T) with the other arm once a week for 8 wk using a dumbbell representing 50% of maximal isometric force of the elbow flexors (MIF) determined at the elbow joint of 90° (1.57 rad). The dumbbell was lowered from a flexed (50°, 0.87 rad) to an extended elbow position (180°, 3.14 rad) in 3 s for ECC-T, and lifted from the extended to the flexed position in 3 s for CON-T. Max-ECC was performed 4 wk after CON-T and 6 wk after ECC-T. Changes in MIF, range of motion (ROM), upper arm circumference (CIR), muscle soreness (SOR), and plasma creatine kinase (CK) activity were compared between the ECC-T and CON-T arms. Results The first ECC-T session produced larger decreases in MIF and ROM, and larger increases in CIR and SOR compared with CON-T. CK increased significantly (P < 0.01) and peaked 4 d after the first training session, but did not increase in the following sessions. All measures changed significantly (P < 0.01) following Max-ECC; however, the changes were not significantly different between ECC-T and CON-T arms. Conclusion These results showed that ECC-T did not mitigate the magnitude of muscle damage more than CON-T, and CON-T did not exacerbate muscle damage.