Local, proximal, and distal effects of resistance training with blood flow restriction on strength and size of upper limb muscles in healthy individuals: A systematic review

Introduction: Resistance training with blood flow restriction (BFR) can promote gains in muscle strength and size using low-load protocols. Objective: To gather the evidence on local, proximal, and distal effects of resistance training with BFR on the strength and size of upper limb muscles in healthy individuals. Methods: Searches were performed in CENTRAL, PEDro, MEDLINE, SciELO, SCOPUS, and Science Direct databases from inception to March 2023. Clinical trials that compared the effects of resistance training with and without BFR ( >= 4 weeks) on the strength and size of upper limb muscles in healthy individuals were included. Data related to studies ' participants, BFR techniques, resistance training protocols, outcomes and assessment measures, and main results were collected. The risk of bias and quality of evidence was assessed using the Cochrane Risk of Bias Analysis Tool and the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach, respectively. Results: Twenty-three studies with a low-high risk of bias and a very-low-to-high quality were included in this review. In general, findings suggest that either high- or low-load resistance training with BFR provided greater local, proximal, and/or distal gains in muscle size and strength compared to resistance training without BFR. Conclusions: Resistance training with BFR can increase the strength and size of upper limb muscles in healthy individuals. Caution must be taken when interpreting and generalizing the results gathered in this review high heterogeneity of the included studies ' methods.