Respostas psicofisiológicas decorrentes da aplicação de estímulos e intervalos autosselecionados em sessões de High-Intensity Interval Resistance Training em homens treinados

Abstract

Introduction: Among the exercise prescription variables that enable sustaining high intensities in High-Intensity Interval Resistance Training (HIRT), the duration of stimuli and the recovery intervals between them stand out. An interesting strategy to determine the duration of stimuli and rest intervals not yet investigated in HIRT is the use of self-selected durations. Objective: Analyze the effect of fixed versus self-selected durations on psychophysiological responses in trained men performing HIRT sessions. Methods: Two separate studies were conducted on different groups. All subjects initially underwent a clinical examination and a cardiopulmonary exercise test on a treadmill. Subsequently, a familiarization with the HIRT circuits and with the devices used to perform them was carried out. In study one, from the third to the fifth day, three sessions of a HIRT circuit, consisting of four passages of four exercises, were performed in a random order. The sessions were performed with different recovery intervals between stimuli, namely: 10s (FRI-10), 30s (FRI-30) and self-selected (SSRI). In study two, on the third and fourth days, two HIRT sessions were applied: the first with self-selected stimuli duration (HIRT-AS) and the second with a fixed stimuli duration of 20s (HIRT-20). On both days, the recovery interval between stimuli was fixed at 10s, in a circuit composed of three passages in six exercises. During the exercise sessions, ventilatory variables, heart rate (HR), blood lactate, recovery perception, training volume, affective, and enjoyment responses were monitored. Parametric statistics were used for data analysis, adopting a significance level of p < 0.05. Results: Study 1: Oxygen consumption (VO2) during exercise was higher in the FRI-10 (55% VO2max) than in the FRI-30 (47% VO2max - FRI-30) (p = 0.01), while there was no difference between SSRI (52% VO2max) and sessions performed at fixed intervals (p > 0.05). HR, EPOC, perceived recovery, and enjoyment responses were similar across conditions (p > 0.05). Study 2: VO2 and HR were higher in HIRT-FX vs. HIRT-AS (HIRT-FX = 51%VO2max; HIRT-AS = 48%VO2max, p=0.04; HIRT-FX = 90%HRmax; HIRT-AS = 88%HRmax, p = 0.04, respectively) , but with low magnitude effect sizes (ES = 0.28; ES = 0.21, respectively). The training volume and duration were higher in HIRT-FX compared to HIRT-AS (p < 0.05; ES > 0.70). The blood lactate responses, affective, and enjoyment variables were not affected by the different stimuli duration strategies (p > 0.05). Conclusions: Self-selection of stimulus duration and recovery intervals in HIRT sessions seems to be as efficient as fixed duration stimuli and rest intervals in maintaining high intensity. On the other hand, training volume and time sustained at high intensities are negatively affected by self-selection of stimulus duration. In addition, the way in which the studied variables are established in HIRT (fixed or self-selected) does not seem to influence affective and enjoyment responses in trained men. Depending on the prescription goals, self-selection of stimulus duration and recovery intervals may be a useful strategy to be adopted in HIRT sessions applied to trained individuals