Influência de diferentes intervalos de recuperação sobre o tempo sob tensão, parâmetros neuromusculares e hemodinâmicos em séries múltiplas no exercício supino reto

Abstract

Introduction: The rest interval (RI) variable is important in the prescription of strength training. However, different objectives and instrumentation are used to assess the responses to manipulation of this variable, and there is no information in the literature about the behavior of different RIs in time under tension (TUT) and their influence on the response to exercise. Thus, the aim of the present study was to evaluate the influence of two different rest intervals on neuromuscular and hemodynamic parameters in bench press exercise. METHODS: To elucidate the guiding questions, a systematic review and an experimental protocol was carried out using the bench press exercise to determine the TUT and subsequent evaluation in the execution of 3 sets with rest intervals of 90s (RI90) and 180s (RI180) among them. The number of completed repetitions (NR), TUT, lactate levels (LAC), muscle strength (MS), total load volume (TLV), total load (TL), Fatigue Index (FI) and Efficiency (EF). The hemodynamic variables: blood pressure, heart rate (HR) and perceived exertion (PE). RESULTS: Through the Systematic Review, it was possible to observe that the studies presented verified the influence of different rest intervals on muscle and hemodynamic responses, however separately and without including the TUT. With the experimental protocol it was possible to determine the TUT for 8, 10 and 12RM in the bench press (14.22 seconds, 17.18 seconds and 20.66 seconds, respectively). None of the intervals were able to maintain the NR in the subsequent series (p<0.001). Only the RI180 was able to maintain the TUT. LAC levels were higher after series 3 (S3) compared to pre-exercise (p = 0.019; d = 6.61; Δ% = 201.66%) in RI90 and after the second (S2) (p = 0.003) and S3 (p < 0.001; d = 7.84, Δ% = 249.68%) in the RI180. In both protocols there was a decrease in MS after S3 (RI90 = p < 0.001; d = -1.25; Δ% = - 45.82% / RI180 = p < 0.001; d = -1.22; Δ% = - 44.15%). The RI180 had higher TLV (p = 0.004) and higher TL (p = 0.009). No differences were found in LAC, MS, FI and EF between RI90 and RI180 (p > 0.005). For hemodynamic variables, there was no difference between series or between protocols in Systolic Blood Pressure (SBP), HR and PE. Diastolic blood pressure (DBP) at S2 was lower than that verified before exercise (p < 0.001) and immediately after S1 (p = 0.014). There was also a lower DBP in the RI90 (p = 0.009). CONCLUSION: The TUT variable seems to be important to assess responses to physical exercise. The RI180 proved to be more efficient to promote performance recovery, when compared to the RI90, and should be prioritized for training with the objective of maintaining the training volume. However, the RI90 presented lower values for the DBP throughout the series and when compared to the RI180