Alterações do tecido adiposo promovidas por diferentes protocolos de treinamento físico seguidos por período de destreino

Abstract

General adaptation syndrome and the overcompensation model are frequently applied themes in exercise science. Metabolic changes in response to exercise-induced stimuli can promote compensatory effects in different systems, including organic tissues and energy substrates. It has been identified that specific training protocols can promote compensatory effects in concentrations of energy substrates and body tissues. In this sense, previous evidence suggests that muscle tissue and adipose tissue also present compensatory effects. However, there are no specific investigations comparing compensatory effects of high-intensity intermittent exercise and moderate-intensity continuous exercise on body fat. Therefore, this doctoral thesis builds the hypothesis that, considering that fat is an essential tissue and primary energy source for moderateintensity continuous exercise, this type of effort could promote compensation and adverse effects linked to obesogenic factors after a period of detraining. Therefore, this biological response was investigated to determine whether or not the compensatory effect is dependent on exercise protocols. Therefore, the objective of this thesis was to investigate the effects of different exercise models on tissue cellularity, and specifically on supercompensatory processes during the detraining period. For this purpose, the following were conducted: i) a systematic review of the literature with meta-analysis on the effects of physical detraining on adipocyte mass and an ii) experimental study, in which rats were allocated into three groups: a) Moderateintensity continuous training (MICT); b) High-intensity interval training (HIIT); and c) Control group (CG). The animals exercised on a treadmill for eight weeks and were monitored for four weeks after stopping physical exercise. Morphometric variables were evaluated at baseline, after eight weeks of training, and after four weeks of detraining. From the results of the intervention study, it was observed that there was an increase in the area of perilumbar and perirenal adipose tissue after detraining, and lower weight of perilumbar adipose tissue in the MICT and MICT when compared to the CG; HIIT and MICT showed lower mean values of perirenal adipose tissue weight when compared to the CG. Finally, the percentage of decline in glycemia was more significant in the HIIT group when compared to the CG. The results obtained from the meta-analysis revealed that adipocyte mass and body mass were lower in trained rats (whether submitted to HIIT or MICT) compared to the control group. However, there was no significant effect on adipocyte area, adipocyte diameter or insulin resistance. This thesis shows that both HIIT and MICT can minimize the compensatory effects of adipose tissue mass after detraining. HIIT, in particular, showed additional benefits in glycemic control, and the results of the meta-analysis corroborate these findings.