Effect of walk training combined with blood flow restriction on resting heart rate variability and resting blood pressure in middle-aged men

Abstract

To investigate the effects of low-intensity walk training with and without blood flow restriction (BRF) on resting heart rate variability (HRV) and blood pressure (BP) in middle-aged men. Methods: Twenty-one men were randomly assigned into the walk training group with (BRF-W; n = 11) and without (NOR-W; n = 10) BFR. The resting HRV and blood pressure were assessed pre-and post-6 weeks of the intervention [3 times/week, 5 sets of 3-min walking (6 km.h-1) with 1-min of rest, totalizing 18 sessions of training]. The BFR-W group received the occlusive stimulus before of training sessions though of a standard sphygmomanometer and performed the training sessions with the vascular occlusion (80-100 mmHg) in both the legs. Results: Only BRF-W group improved HRV on time domain indices (SDNN and RMSSD; p < 0.05) after training but it was not found differences on frequency domain indices. In addition, systolic blood pressure (SBP) improved after training (PRE: 128.5 ± 5.9 vs POST: 119.1 ± 8.6 mmHg; Cohen's d =-1.30; p < 0.01) only in BFR-W group. There was not a significant difference on diastolic blood pressure (DBP) after training, however, effect size was moderate for BFR-W (Cohen's d =-0.56; p > 0.05). Conclusion: Our results showed that walking training with blood flow restriction can improve health cardiovascular parameters in middle-aged men.

Blood Flow Restriction Training: To Adjust or Not Adjust the Cuff Pressure Over an Intervention Period?

“…More recently, Kambič et al (2019) observed a reduced systolic BP of patients with coronary artery disease following 8 weeks of knee extension BFR training (30-40% 1RM; 3 sets of 8-12 reps; 2x/week; BFRP ∼140 mmHg). Lastly, two studies verified an increase in HR variability (Ferreira Junior et al, 2019;Junior et al, 2019). Although literature is inconsistent, there is evidence to support that BFR training may reduce both HR and BP and increase HR variability in clinical populations.…”

“…Most included studies were performed with young adults, middle-aged and older adults, with or without clinical conditions, and used lower limb exercises (i.e., leg press, knee extension and flexion, or heel raises) ( Kim et al, 2009 ; Evans et al, 2010 ; Patterson and Ferguson, 2010 , 2011 ; Clark et al, 2011 ; Kacin and Strazar, 2011 ; Fahs et al, 2012 , 2014 ; Hunt et al, 2013 ; Yasuda et al, 2014 ; Kambič et al, 2019 ). Studies also used upper limb exercises (i.e., handgrip, elbow flexion, bench press, or triceps down) ( Credeur et al, 2010 ; Hunt et al, 2012 ; Ozaki et al, 2013 ; Yasuda et al, 2015b ; Cezar et al, 2016 ; Kim et al, 2017 ; Crisafulli et al, 2018 ) and treadmill walking ( Ferreira Junior et al, 2019 ; Junior et al, 2019 ). Importantly, many of the included studies had methodological limitations, such as failure in allocation concealment, blinding of participants and assessors; and intention-to-treat analysis ( Table 3 ).…”

“…Rationale and methods for BFRP adjustments during BFR training interventions are diverse. Those who justified, argued that adjustments were performed to achieve high levels of perceived effort ( Yasuda et al, 2014 , 2015b ), allow participants to adapt to the occlusion stimulus during the early phase of training ( Ferreira Junior et al, 2019 ; Junior et al, 2019 ), impose progressive overload in skeletal muscles and central circulation ( Ozaki et al, 2011 ), adjust BFRP to systolic BP in each session ( Cezar et al, 2016 ), or reduce arterial blood flow by 60% at rest and 30% during exercise ( Ozaki et al, 2013 ).…”

“…In three studies, BFRP adjustment was based on systolic BP changes (75–150% of the systolic BP) ( Cezar et al, 2016 ; Crisafulli et al, 2018 ; Kambič et al, 2019 ), whereas six studies adjusted it arbitrarily by applying absolute restriction pressures ranging from 80 to 270 mmHg ( Ozaki et al, 2011 , 2013 ; Fahs et al, 2012 ; Yasuda et al, 2015b ; Ferreira Junior et al, 2019 ; Junior et al, 2019 ). Applying arbitrary or SBP-based cuff pressures has not encouraged ( Patterson et al, 2019 ).…”

“…Overall, no significant changes in HR were found in young participants, while diastolic BP was significantly reduced (−7 mmHg) in one study ( Fahs et al, 2012 ) and increased (7 mmHg) in another study ( Kacin and Strazar, 2011 ). In middle-aged and older adults, one study found a significant decrease in systolic BP (−10 mmHg) ( Ferreira Junior et al, 2019 ), and another observed a decrease in HR (−10 bpm) ( Junior et al, 2019 ). In clinical populations, two studies observed decreased systolic BP (−6 to −16 mm Hg) ( Cezar et al, 2016 ; Kambič et al, 2019 ), and one study found a decreased diastolic BP (−11 mmHg) ( Cezar et al, 2016 ).…”