Different types of mechanical vibration application on EMG response and strength performance

Abstract Aim: The present study aimed to compare the strength performance and the neuromuscular activity during one maximum repetition test (1RM), and the maximum voluntary isometric contractions (MVIC) performed with whole-body vibration (WBV), local vibration (LV), and no vibration (NV). Methods: The sample consisted of 15 males, experienced in strength training for at least 6 months, which performed all strength tests in the barbell curl exercise across randomized trials on the following conditions: NV, WBV, and LV. During all tests, the normalized root means square values of the electromyographic signals (EMGRMS) of the biceps brachii and brachioradialis were recorded and compared between the conditions. The one-way ANOVAs with repeated measures were used to compare the results of 1RM and MVIC tests and the normalized EMGRMS between the conditions. When necessary, a post hoc Scott-Knott test was used to identify the differences reported in the ANOVAs. The significance level adopted was α < 0.05. Results: The EMGRMS response of the biceps brachii and brachioradialis muscles during the 1RM and MVIC tests presented significantly higher values at LV compared to WBV, and NV (p < 0.001). The 1RM tests, and the MVIC results were similar between conditions (p = 0.9803; p = 0.061, respectively). Conclusion: These results indicate that the application of MV was not sufficient to increase strength performance.

Comparação do número máximo de repetições em séries múltiplas entre indivíduos com diferentes tempos de experiência no treinamento de força / Comparison of the maximum number of repetitions in multiple series between individuals with different times of experience in resistance training

O treinamento de força (TF) proporciona adaptações centrais e morfológicas que influenciam no processo de produção de força. Em função destas adaptações é esperado que ocorram diferenças no desempenho de força entre homens com diferentes tempos de experiência no TF quanto testados em séries múltiplas. Assim, este estudo teve como objetivo comparar o número máximo de repetições (NMR) realizadas em 3 séries entre indivíduos com diferentes tempos de experiência no TF. Para isso, vinte e dois homens foram divididos em dois grupos de acordo com o tempo de experiência no TF. O Grupo Muito Experiente (GME) foi representado por homens com mais de 5 anos no TF. O Grupo Pouco Experiente (GPE) foi composto por homens com 1 a 6 meses de experiência no TF. Os grupos foram submetidos à realização do maior número de repetições em três séries a 80% de 1RM no exercício supino reto. Além disso, a duração média da repetição (DMR) foi registrada e comparada em cada série intra e inter grupos. Para as comparações foram utilizadas duas ANOVAs com única variável (NMR ou DMR) e dois fatores (fator 1 = experiência, fator 2 = série). Na análise do NMR foi detectada uma interação entre os fatores, sendo que o número máximo de repetições realizado pelo GME foi maior do que o GPE apenas na primeira série (p = 0,017). Quanto à DMR, não foram encontradas diferenças entre os grupos (p = 0,80) e séries (p= 0,06). Conclui-se que o tempo de experiência no TF interferiu na realização do número máximo de repetições apenas na primeira série... (AU)

Strength training (TF) provides central and morphological adaptations that influence the process of force production. Due to these adaptations, it is expected that differences in force performance occurred between men with different times of experience in the TF when tested in multiple series. Thus, this study had as objective to compare the maximum number of repetitions (NMR) performed in 3 sets between individuals with different times of experience in the TF. For this, twenty-two men were split into two groups according to the time of experience in the TF. The Very Experienced Group (GME) was represented by men older with at least 5 years in TF. The Little Experienced Group (GPE) was composed of men with 1 to 6 months of experience in TF. The groups were submitted to perform the highest number of repetitions in three sets at 80% of 1RM in the bench press exercise. In addition, mean repetition duration (DMR) was recorded and compared in each set and group. For the comparison, two ANOVAs with a single variable (NMR or DMR) and two factors (factor 1 = experience, factor 2 = set) were used. In the NMR analysis, an interaction between the factors was detected, and the NMR performed by the GME was higher than the GPE only at the first set (p = 0.017). Regarding DMR, no differences were found between groups (p = 0.80) and sets (p = 0,06). It is concluded that the time of experience in the TF interfered in the Performance of the maximum number of repetitions only at the first set...(AU)