Suplementação de cafeína e treinamento de força: efeito ergogênico e comportamento hemodinâmico agudo em relação a intensidade de treinamento

Abstract

Increases in strength and muscular hypertrophy are the main objectives desired with the practice of strength training (TF), in order to optimize these adaptations the appropriate manipulation of the variables that make up the training sessions orders the proportion of their effects. In parallel to PT planning, nutritional control is used as a strategy to enhance its results, and in this context, acute caffeine supplementation (CAF) through its ergogenic power is scientifically proven to improve performance. Several physiological factors are involved in the production of fatigue and consequently in the reduction of performance, there is an association between the organization of training and its magnitude, since CAF has an action on different mechanisms involved in the neuromotor control of force production, In addition to its interaction with the cardiovascular system, this study sought to analyze the acute effect of CAF interaction, given different intensities in TF, evaluating factors controlling performance and cardiovascular responses. Nine men experienced in RT used CAF capsules at a concentration of 6mg/kg of body weight in three test protocols at intensities of 50%, 70% and 90% of the maximum load, in the bench press exercise. For each of the 3 intensities, two placebo groups (PLA) and CAF were controlled, making participants go through both conditions. The study was double blind and lasted 25 days, 7 of which included visits to the data collection site. Hemodynamic behavior was analyzed by measuring heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP) and double product (DP), analyzed at 7 moments during the test protocol. : rest for 5 minutes, 60 minutes after ingesting the capsules, immediately after finishing the 4 sets and 20 minutes after finishing the exercise. Performance assessments were verified by quantifying the number of repetitions, total volume of work (VTT) and time under tension (TST) per series and exercise, added to the observation of the fatigue index (FI) and subjective perception of effort ( PSE). The -T Test was used for paired analyzes and a Two-Way ANOVA for the others. In the performance variables, no significant differences were diagnosed in any of the comparisons carried out when CAF was supplemented in relation to PLA, however, when comparing the intensities it was noticed that CAF can promote a greater magnitude of interference at 90% of 1RM. For hemodynamic responses, there were significant differences in HR and DP under exertion (p=0.04 and 0.05), in the magnitude of post-exercise SBP (p= 0.031), and in the magnitude of post-exercise MAP only at 70% of 1RM (p=0.036), with higher values for the use of CAF, in the other comparisons carried out there was no presence of statistical differences. It is concluded that 6mg/kg of CAF was not enough to increase performance at various intensities in RT, but it was enough to increase the response of the cardiovascular system during effort and attenuate post-exercise hypotension.