Respostas da atividade eletromiográfica e concentração de lactato sanguíneo a protocolos de treinamento de força equiparados pelo tempo sob tensão

Abstract

The aim of this study was to investigate the impact of resistance training protocols equalized by the time under tension (TUT), but composed of different repetition durations and number of repetitions, in muscle activation and blood lactate concentration. Twenty-two with previous experience in resistance training performed two resistance training protocols (A and B) in the Smith machine bench press exercise, both with 3 sets, 3 minutes rest, and 60% of one repetition maximum (1RM). The Protocol A consisted of 6 repetitions with 6s repetition duration for each repetition, while in the Protocol B the subjects performed 12 repetitions with 3s repetition duration for each repetition. The muscular activation was measured in the anterior deltoid, pectoralis major, and triceps brachii muscles while performing the two resistance training protocols. The normalized root mean square of the electromyographic signal amplitude (EMGRMS) was calculated for each set. The blood lactate concentration was measured during and up to 12 minutes after the completion of the protocol. The results showed that the EMGRMS of all muscles increased during the sets and was higher in Protocol B when compared to the Protocol A. Likewise, the blood lactate concentration also increased throughout the sets and was higher in Protocol B both during and after the completion of the training session. The data obtained in this study show that training protocols conducted with the same TUT, but with different configurations, produce distinct neuromuscular and metabolic responses. Thus, performing a higher number of repetitions with shorter repetition durations might be a more appropriate strategy to increase muscle activation and blood lactate concentration.