Acute hemodynamic responses from low-load resistance exercise with blood flow restriction in young and older individuals: A systematic review and meta-analysis of cross-over trials.

Objective: To summarize the existing evidence on the acute response of low-load (LL) resistance exercise (RE) with blood flow restriction (BFR) on hemodynamic parameters.

Data Sources: MEDLINE (via PubMed), EMBASE (via Scopus), SPORTDiscus, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, Web of Science and MedRxiv databases were searched from inception to February 2022.

Review Methods: Cross-over trials investigating the acute effect of LLRE + BFR versus passive (no exercise) and active control methods (LLRE or HLRE) on heart rate (HR), systolic (SBP), diastolic (DBP) and mean (MBP) blood pressure responses.

Results: The quality of the studies was assessed using the PEDro scale, risk of bias using the RoB 2.0 tool for cross-over trials and certainty of the evidence using the GRADE method. A total of 15 randomized cross-over studies with 466 participants were eligible for analyses. Our data showed that LLRE + BFR increases all hemodynamic parameters compared to passive control, but not compared to conventional resistance exercise. Subgroup analysis did not demonstrate any differences between LLRE + BFR and low- (LL) or high-load (HL) resistance exercise protocols. Studies including younger volunteers presented higher chronotropic responses (HR) than those with older volunteers.

Conclusions: Despite causing notable hemodynamic responses compared to no exercise, the short-term LL resistance exercise with BFR modulates all hemodynamic parameters HR, SBP, DBP and MBP, similarly to a conventional resistance exercise protocol, whether at low or high-intensity. The chronotropic response is slightly higher in younger healthy individuals despite the similarity regarding pressure parameters.