La velocidad de ejecución voluntaria como indicador de la intensidad y de la respuesta neuromuscular durante el entrenamiento de fuerzafiabilidad y efectos a corto y medio plazo.

Abstract

The present Doctoral Thesis is composed of 5 consecutives studies. All of them were carried out following a main thread and supported by results and findings obtained in the previous studies. The main goal of this Doctoral Thesis was to analyze the importance, and the acute- and long-term effects of movement velocity during resistance training (RT) on several mechanic, metabolic and electromyography (EMG) variables depending on the voluntary lifting velocity with different percentages of the maximal movement velocity against the same relative loads. In the Study I, it was analyzed the reliability and reproducibility of several mechanics and EMG variables against different relative loads. The aim was assessed the reliability in order to select the most reliable variables to be use in the next studies. Thus, we could avoid or exclude those variables with inadequate reliability and that the variability of these variables did not influence the effects produced by the independent variable "voluntary movement velocity". Once the variables had been selected in the previous study, the purpose of the Study II was evaluated the responses on these mechanical and EMG variables induced by different movement velocities (100%, 75%, 50% y 25% from the maximum voluntary movement velocity) against the same relative loads (50%, 60%, 70%, and 80% 1RM) in the full squat (SQ) and bench press (BP) exercises. Study III examined the changes in mechanic, metabolic and EMG variables following different resistance exercise protocols (REP) in the SQ exercise with different relative loads (45%, 50%, 55%, 60% and 65% 1RM) and repetitions per set well ahead from muscular failure. REPs only differ in the voluntary movement velocity: "as fast as possible" condition (MaxV), at "half of this maximum voluntary velocity" condition (HalfV). In the study IV, once the response against different REP with a number of repetitions away from muscle failure are analyzed, we examined the response against REPs performed until muscular failure using 2 relative loads (50% and 70% 1RM) and 2 velocity conditions [as fast as possible (MaxV) and the half of this maximun velocity (HalfV) in the SQ and BP exercises. The changes in mechanic, metabolic and EMG variables were assessed after each REP. Finally, in the Study V, it was analyzed the long-term effect of a 6-week RT program with moderate relative loads (45% - 65% 1RM) and low number of repetitions per set in the SQ exercise comparing 2 lifting velocities: one group performed each repetition as fast as possible (MaxV) and the other group performed each repetition at a half of this maximum velocity (HalfV). The training effect was evaluated through the changes in muscle strength and endurance, jumping and sprinting ability, and cycle ergometer endurance.