Comparação do treinamento bi-set composto e bi-set tradicional sobre parâmetros de composição corporal e biomarcadores redox-purinérgicos em mulheres adultas praticantes de exercício físico resistido

Abstract

Resistance exercise (RE) is an established strategy for promoting muscular and metabolic adaptations; however, different set arrangements may alter training density and influence responses related to body composition and redox balance. This study compared the effects of the compound bi-set (BSC) and the traditional bi-set (BST) on body composition, purinergic markers, and redox markers in adult women engaged in RE. This was a pilot clinical trial with an interventional, analytical, and comparative design, comprising 26 participants in the BSC (n = 17) and BST (n = 9) groups, with lean mass and fat mass as primary outcomes and all remaining variables as secondary outcomes. The intervention lasted 12 weeks, with three weekly sessions of approximately 60 minutes; in the BSC each block followed the sequence Exercise 1 → Exercise 2 → Exercise 1, and in the BST the sequence Exercise 1 → Exercise 2. Blood samples were collected under fasting conditions before the intervention and within 48 hours after the final session. Platelet NTPDase, ecto-5'-nucleotidase, and adenosine deaminase (ADA) activities were assessed, along with extracellular ATP levels and the redox markers total thiols, non-protein thiols (NPSH), thiobarbituric acid reactive substances (TBARS), and myeloperoxidase (MPO). The BSC showed a significant increase in lean mass (42.1 → 44.3 kg; p < 0.001) and a reduction in fat mass (22.8 → 20.2 kg; p < 0.001), whereas in the BST lean mass did not change and fat mass increased (19.6 → 22.4 kg; p < 0.01). The BSC also showed reductions in the suprailiac and biceps skinfolds and an increase in hip circumference, with a significant interaction, plus within-group reductions in waist and neck circumferences. Regarding the purinergic system, ADP hydrolysis by NTPDase and ADA activity decreased in the BST, with no changes in the BSC, in which extracellular ATP increased. Total thiols and MPO increased in both groups, whereas the increase in NPSH and the reduction in TBARS (0.68 → 0.30 nmol MDA/mg) were restricted to the BSC, as was the increase in IL-10. No significant changes were observed in IFN-γ, TNF, IL-6, IL-4, NTPDase with ATP as substrate, ecto-5'-nucleotidase, total cholesterol, HDL, LDL, triglycerides, or VLDL, with only a reduction in fasting blood glucose restricted to the BST. Outcomes with a significant time × protocol interaction showed large effect sizes. Antioxidant modulation was selective, since total thiols increased in both protocols but the reduction in lipid peroxidation and the increase in non-protein thiols occurred only in the BSC. It is concluded that, under the conditions of this study, the BSC protocol showed the most favorable body remodeling, with lean mass gain, reduction of fat mass and skinfolds, and reduced lipid peroxidation as assessed by TBARS. The purinergic, inflammatory, and biochemical responses were selective and, with the exception of ADP hydrolysis by NTPDase, restricted to within-group changes, with no statistical support to claim superiority between the protocols, which requires confirmation in studies with larger samples and balanced groups.