A single bout of resistance training, especially with eccentric actions, induces damage to the muscle structure. Characteristics of eccentric actions may increase muscle damage. The number and intensity of contractions seem to affect the magnitude of muscle damage. Thus, the aim of this study was to investigate if the number and the intensity of contraction increase muscle damage, 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 (EXC30-70, n = 8). Another group performed the same number of repetitions, but at 110% of 1RM (EXC30-110, n = 8). A third group performed a higher number of repetitions (60) at 70% of 1RM (EXC60-70, 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 more remarkable larger in EXC30-110 compared to EXC30-70 and EXC60-70. These data suggest that eccentric action intensity affects the magnitude of muscle damage more than the number of contractions.
muscle strength; range of motion; resistance training
