title: Effect of eccentric contraction velocity on muscle damage in repeated bouts of elbow flexor exercise.
abstract: Eccentric exercise induces muscle damage, but controversy exists concerning the effect of contraction velocity on the magnitude of muscle damage, and little is known about the effect of contraction velocity on the repeated-bout effect. This study examined slow (60 degrees.s(-1)) and fast (180 degrees.s(-1)) velocity eccentric exercises for changes in indirect markers of muscle damage following 3 exercise bouts that were performed every 2 weeks. Fifteen young men were divided into 2 groups based on the velocity of eccentric exercise: 7 in the Ecc60 (60 degrees.s(-1)) group, and 8 in the Ecc180 (180 degrees.s(-1)) group. The exercise consisted of 30 maximal eccentric contractions of the elbow flexors at each velocity, in which the elbow joint was forcibly extended from 60 degrees to 180 degrees (full extension) on an isokinetic dynamometer. Changes in maximal voluntary isometric contraction strength, range of motion, muscle soreness, and plasma creatine kinase activity before and for 4 days after the exercise were compared in the 2 groups using a mixed-model analysis (groupxboutxtime). No significant differences between groups were evident for changes in any variables following exercise bouts; however, the changes were significantly smaller (p<0.05) after the second and third bouts than after the first bout. These results indicate that the contraction velocity does not influence muscle damage or the repeated-bout effect.
authors: School of Physical Education and Sport, University of São Paulo, São Paulo, Brazil.
authors: Renato
authors: R
authors: Barroso
authors: Hamilton
authors: H
authors: Roschel
authors: Carlos
authors: C
authors: Ugrinowitsch
authors: Rubens
authors: R
authors: Araújo
authors: Kazunori
authors: K
authors: Nosaka
authors: Valmor
authors: V
authors: Tricoli
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D001938:Brazil; D003402:Creatine Kinase / Q000097:blood; D004550:Elbow; D004551:Elbow Joint / Q000503:physiopathology; D015444:Exercise; D006801:Humans; D007537:Isometric Contraction; D008297:Male; D053580:Muscle Strength; D018482:Muscle, Skeletal / Q000201:enzymology / Q000473:pathology / Q000503:physiopathology*; D009135:Muscular Diseases / Q000097:blood / Q000209:etiology* / Q000473:pathology / Q000503:physiopathology; D010146:Pain / Q000209:etiology; D016059:Range of Motion, Articular; D013997:Time Factors; D055815:Young Adult
chemical_list: D015415:Biomarkers; D003402:Creatine Kinase