Efeitos do treinamento resistido e destreinamento nas variáveis hemodinâmicas, metabólicas e composição corporal em idosas com síndrome metabólica submetidas a 60% e a 80% de restrição de fluxo sanguíneo

Abstract

Aim: To evaluate the effects of resistance training and detraining on hemodynamic, metabolic and body composition variables in elderly women with metabolic syndrome who underwent two percentages of blood flow restriction. Materials and Methods: A double-blind, controlled, randomized, clinical trial, with 39 female subjects aged 64.4 ± 4.5 years, height of 1.52 ± 6.4 m and weight of 65.0 ± 10.5 kg, who underwent low-intensity resistance exercise at 20% of maximal strength using vascular occlusion equipment, randomly allocated to three groups: 1) 0% of total vascular occlusion pressure (GCP) (n=13); 2) Group 60% blood flow restriction (RFS60) (n=13); 3) Group 80% blood flow restriction (RFS80) (n=13); cardiovascular responses were assessed by ambulatory blood pressure monitoring; muscle strength was measured by the one repetition maximum test; body composition was assessed by skin folds; subjects completed three sets of fifteen repetitions, sixty second intervals between sets, alternated by segment, in the exercises: leg press, elbow extension, knee extension, and elbow flexion; twice a week, every other day, for eight weeks; then undergoing exercise interruption for four weeks; statistical analysis was performed using GraphPad Prism software; significance level of p <0.05. Results: after the first exercise session, there was a significant reduction in comparisons between groups and between the moments evaluated for cardiovascular variables; after eight weeks of training, cardioprotective effects of exercise associated with blood flow restriction were more significant in the RFS60 group than in the RFS80 group (p<0.05), as systolic blood pressure decreased -6.5 mmHg and heart rate -4.1 bpm relative to baseline; still increased muscle strength and reduced body composition; after four weeks of detraining, most variables returned to pre-training values; heart rate remained reduced by -4.1 bpm and muscle strength increased in the RFS60 group; there was no significant improvement in lipid profile (p>0.05); there was no difference between the groups. Discussion: The hypotensive effect and improvement in muscle strength and body composition after an eight-week training protocol partially confirmed the initial findings of the first exercise session, which may have enabled a greater exercise pressor reflex, mediated by muscle mechanoreceptors and metaboreceptors, reduced resistance. peripheral vascular disease, greater secretion of nitric oxide promoting vasodilation, and possible improvement of endothelial function, especially when blood flow was restricted to 60%. Conclusion: this scientific evidence suggests that low-intensity resistance exercise with two percent blood flow restriction provided cardiovascular, muscle strength and body composition improvements in elderly women with metabolic syndrome after eight weeks of training, as well as after four weeks of detraining; the protective effects were better when blood flow was restricted to 60% compared to 80%.