Acute effect of low-load resistance exercise with blood flow restriction on oxidative stress biomarkers: A systematic review and meta-analysis

BACKGROUND: The purpose of this review was to analyze the acute effects of low-load resistance exercise with blood flow restriction (LLE-BFR) on oxidative stress markers in healthy individuals in comparison with LLE or high-load resistance exercise (HLRE) without BFR. MATERIALS AND METHODS: A systematic review was performed in accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. These searches were performed in CENTRAL, SPORTDiscus, EMBASE, PubMed, CINAHL and Virtual Health Library- VHL, which includes Lilacs, Medline and SciELO. The risk of bias and quality of evidence were assessed through the PEDro scale and GRADE system, respectively. RESULTS: Thirteen randomized clinical trials were included in this review (total n = 158 subjects). Results showed lower post-exercise damage to lipids (SMD = -0.95 CI 95%: -1.49 to -0. 40, I(2) = 0%, p = 0.0007), proteins (SMD = -1.39 CI 95%: -2.11 to -0.68, I(2) = 51%, p = 0.0001) and redox imbalance (SMD = -0.96 CI 95%: -1.65 to -0.28, I(2) = 0%, p = 0.006) in favor of LLRE-BFR compared to HLRE. HLRE presents higher post-exercise superoxide dismutase activity but in the other biomarkers and time points, no significant differences between conditions were observed. For LLRE-BFR and LLRE, we found no difference between the comparisons performed at any time point. CONCLUSIONS: Based on the available evidence from randomized trials, providing very low or low certainty of evidence, this review demonstrates that LLRE-BFR promotes less oxidative stress when compared to HLRE but no difference in levels of oxidative damage biomarkers and endogenous antioxidants between LLRE. TRIAL REGISTRATION: Register number: PROSPERO number: CRD42020183204.