Efeito do número e intensidade das ações excêntricas nos indicadores de dano muscular

Abstract

A single bout of resistance training, especially those comprising the performance of eccentric actions, induces damage to the muscle structure. Some characteristics of the eccentric exercise bout (i.e. the number and the intensity of contractions) may increase muscle damage. Thus, the aim of this study was to investigate if the number and the intensity of the eccentric muscle actions significantly increase muscle damage (as evaluated through alterations in indirect markers of muscle damage). Twenty-four young male adults were randomly placed into three groups. One of the groups performed 30 eccentric actions of the elbow flexors at 70% of 1RM (ECC30-70, n = 8). Another group performed the same number of repetitions, but at 110% of 1RM (ECC30-110, n = 8). A third group performed a higher number of repetitions (60) at 70% of 1RM (ECC60-70, n = 8). Range of motion, limb girth, maximal dynamic strength (1RM) and muscle soreness were assessed before, immediately after, 48h and 96h post exercise. Results were analyzed by a 2-way ANOVA and showed that alterations were significantly greater in ECC30-110 when compared with ECC30-70 and ECC60-70. These data suggest that the intensity of the eccentric actions significantly affects the magnitude of muscle damage in a more pronounced way than the number of contractions.