Efeito do treinamento resistido com diferentes cargas e posicionamentos de segmentos corporais na força, hipertrofia, potência e resistência muscular e sinal eletromiográfico em homens treinados

Abstract

For a resistance training program to promote the desired adaptations, a complex interaction of the different training manipulation variables is necessary. The correct manipulation of the variables can contribute to increase the chances of a training program having the desired effects. Therefore, it is important to understand the influence of these variables on adaptations in the muscular system. Considering that there is a need to know the effects of training variables, the general objective of this study was to analyze the effect of resistance training with different loads and positions of body segments on strength, power and muscular resistance and on the electromyographic signal in trained men. To meet the general objective, specific objectives were established in the conduct of three studies: 1) Effects of resistance training performed with different loads on muscle strength and hypertrophy: a systematic review; 2) Effects of periodized resistance training with high or low loads on muscle strength, power and endurance and electromyographic signal; 3) Electromyographic activation of the pectoralis major and triceps brachii during the dumbbell pullover performed with high load in different positions of the elbows. The results found in study 1, show that robust gains in maximum muscle strength were more pronounced with high loads than with moderate and low loads. However, for muscle hypertrophy, studies indicate that a broad spectrum of lifted load (ie, 30 to 90% of 1RM) can be used for untrained or trained individuals. In study 2, no interaction effect was found between the high and low loads, that is, no significant differences were observed when comparing the two groups. Both types of training, when the measured effect was verified, showed a significant increase after the intervention. Regardless of the type of training performed, the variables 1RM of Bench Press (p = 0.015), 1RM of Leg Press 45 ° (p = 0.008), 12 RM of Bench Press (p = 0.010), power in the Bench Press (p = 0.021) ), power in the Leg Press 45 ° (p = 0.009) and EMG of the vastus lateralis muscle in the Leg Press 45 ° (p = 0.048) had statistically significant improvements. In study 3, the results show that in both positions of the elbows performed with a high load (extended and flexed), the electromyographic activation of the triceps brachii was greater than that of the pectoralis major (clavicular portion) (p <0.05). However, in relation to the pectoralis major (sternal portion), the triceps brachii showed greater activation with flexed elbows (p = 0.002) and not with extended elbows (p = 0.283). Greater activation was found in the sternal pectoralis major compared to the clavicular performed with the elbows extended (p = 0.039). As a conclusion, in view of the proposal presented, it is clear that loads above 30% 1RM are sufficient to increase muscle hypertrophy. However, for muscle strength, it seems that higher loads are needed. In addition, changes in the body segments present different responses in the electromyographic signal.