Respostas cardiorrespiratórias, metabólicas e de afeto em protocolos HIIRT com e sem estações de corrida

Abstract

HIIRT circuits have been increasingly applied across diverse populations due to their benefits on health indicators and physical fitness. However, literature regarding the effects of manipulating prescription variables on psychophysiological responses to effort remains scarce. This thesis comprises two studies. The first entailed a systematic literature review to synthesize methodological characteristics of studies involving high-intensity circuit protocols executed with resistance exercises on acute effort intensity indicators in healthy young adults, analyzing the application of running stations in these protocols. Conducted in accordance with PRISMA guidelines and covering articles up to September 15, 2023, the search across databases such as PubMed, Embase, Web of Science, and Scielo resulted in 23 studies included, with methodological quality assessed by the TESTEX Scale. This analysis uncovered significant variability in HIIRT circuit methodological characteristics, in training volume (session duration, number of exercises, repetitions, execution order, and circuit rounds), effort intensity indicators (percentage of maximum repetitions, fixed loads, body weight, and all-out methods), exercise characteristics, and overload application methods. A lack of standardization in circuit running stations, especially regarding duration and intensity, was also noted. The original article investigated cardiorespiratory, blood lactate, and affective responses in all-out HIIRT sessions, comparing sessions performed solely with resistance exercises (HIIRT-T) to those combined with running stations (HIIRT-M). The sample consisted of 20 trained young volunteers (24.1±3.4 years, VO2max 50.6±8.7 ml∙kg-1∙min-1), undergoing two 12-minute HIIRT protocols. Key variables analyzed included percentages of maximum heart rate (%HRmax), maximum oxygen consumption (%VO2max), energy expenditure (EE), blood lactate [La], and affect. Results indicated that %HRmax did not significantly differ between HIIRT-T and HIIRT-M protocols (80.40±3.73 vs. 81.30±4.092; p=0.0613), while %VO2max (40.35±7.73 vs. 47.00±11.56; p=0.0414) and EE (103.3±22.50 vs. 118.4±29.35 kcal; p=0.0399) were higher in the protocol with running stations. [La] was significantly higher in the HIIRT-T session compared to HIIRT-M (6.4±3.5 to 9±4.62 vs. 3.96±3.13 to 6.54±2.8 mmol∙L-1; p≤0.05), and there was greater stability in the number of repetitions across rounds in HIIRT-M compared to HIIRT-T (88.44±8.99 to 60.44±8.72 vs. 40.94±4.4 to 46±4.63; p≤0.05). Affective responses, including pleasure, activation, and enjoyment, were not significantly altered by the inclusion of running stations. It is concluded, therefore, that running stations in HIIRT-M circuits are effective in maintaining high effort intensity, with higher VO2 and lower lactate production, which may benefit the reduction of localized fatigue impact in such circuits. The slight difference in EE between HIIRT-M and HIIRT-T protocols, though statistically significant, limits practical implications. The inclusion of running stations did not influence affective responses to exercise. However, further research is needed to investigate the effects of different durations and intensities of running stations in HIIRT protocols, aiming to optimize training strategies