Response Variation In Blood Pressure To Submaximal Blood Flow Restricted Exercise

Previous work has shown that low load resistance exercise paired with blood flow restriction (BFR) can improve muscle function but is often accompanied by augmentation in blood pressure. Individuals who are sensitive to metabolites may have an even further increase. Some have suggested that this can be mitigated by applying the pressure relative to arterial occlusion pressure (AOP). PURPOSE: To determine if there are differential responders in blood pressure responses to submaximal resistance exercise with BFR, and whether the response was influenced by the use absolute or relative BFR pressures. METHODS: 22 participants completed 5 visits. During the first visit, arterial occlusion pressure (AOP), knee extension one-repetition maximum (1RM), and endurance capabilities with 80% AOP were measured. For the next 4 visits, participants completed 2 identical cycles, each involving an exercise visit and time matched control. The exercise involved 2 sets of 30% 1RM unilateral knee extensions (2 sets, 70% of max repetitions) with BFR separated by 30s of rest. BFR was applied either at 80% AOP (relative) or 100 mmHg (absolute), depending on random group assignment. Blood pressure was taken before and after exercise/control conditions. A one sample t-test determined whether there was an effect of exercise on changes in systolic (SBP) and diastolic (DBP) pressure. A within-participant linear mixed model and a random-effects meta-analysis approach were subsequently used to quantify if the change was dependent on pressure applied and if change differed across individuals. RESULTS: Exercise resulted in acute increases in SBP [17 (95%CI: 14.8, 21.1) mmHg] and DBP [11 (95%CI: 8.8, 13.9) mmHg]. Neither change depended upon the pressure application. The linear mixed model provided evidence for an individual response (participant * condition) in SBP (p = 0.013) and DBP (p = 0.04). The individual response SD was 8.3 (95% CI: 3.7, 11.1) mmHg for SBP and 4.8 (95% CI: 0.7, 6.8) mmHg for DBP. The random effects meta-analysis also provided evidence (τ2) for response variation, even when separated by pressure. CONCLUSION: There were individual blood pressure responses to BFR exercise. However, the associated changes were not able to be explained through pressure application. This suggests that the response variation is due to other factors.