The effect of blood flow training restriction on endothelial function and arterial stiffness: A systematic review and meta-analysis

BACKGROUND: Blood flow restriction training (BFRT) is used to enhance low-load exercise, but vascular effects remain uncertain. We compared BFRT with matched non-BFRT exercise on endothelial function, arterial stiffness, and vascular structure. METHODS: This PRISMA 2020 review was preregistered (PROSPERO CRD420251118357). PubMed, Web of Science, Cochrane Library, and Chinese National Knowledge Infrastructure were searched on October 2, 2025, with systematic snowballing. Randomized parallel-group, crossover, or within-subject controlled trials were pooled using random-effects models (three-level or conventional) to estimate Hedges' g; subgroup/meta-regression examined moderators; RoB2, PEDro, and GRADE assessed study quality. RESULTS: Thirty-five trials (n = 764) were included. Overall, BFRT showed no advantage for flow-mediated dilation (FMD; k = 30; g = -0.10) or pulse wave velocity (PWV; k = 32; g = -0.04); pooled effects were also non-significant for blood flow, AIx, CAVI, arterial diameter, and ankle-brachial index. Effects depended on protocol: resistance BFRT improved FMD (g = 0.56), whereas handgrip (g = -0.85) and some interval/aerobic BFRT reduced FMD; interventions <4 weeks decreased FMD (g = -0.69). Low-load BFRT reduced PWV versus high-load resistance training (g = -0.76). Age positively moderated FMD responses; certainty ranged from very low to moderate. CONCLUSIONS: Evidence does not support a generalized vascular benefit of BFRT. Low-load resistance BFR may be most favorable, while small-muscle and moderate-to-high-intensity protocols warrant caution. Larger trials, especially in women and clinical populations, are needed.