Effects of Walking Training with Restricted Blood Flow on HR and HRV Kinetics and HRV Recovery

Abstract

The aim of this study was to investigate the effects of walking training with and without blood flow restriction (BFR) on heart rate (HR) and heart rate variability (HRV) kinetics and HRV recovery. Twenty-one men (53.5±3.2 years; 82.4±13.5 kg; 168.5±7.2 cm) were randomly assigned to two training groups: walk training group with (BFR-W; n=11) and without (NOR-W; n=10) BFR. Before and after training, all subjects underwent body composition evaluation, incremental test, and one constant load test. Walking training was performed 3 times/week, during 6 weeks. Each session was composed by 5 sets of 3-min walking and 1-min rest between the sets. All parameters of HR on- and off-kinetics and RMSSD15 0 parameter of HRV on-kinetics were improved for BFR-W group after training (p<0.05), with an interaction effect for HR on-kinetics parameters and RMSSD15 0 parameter (p<0.05). Also, parameters of time and frequency domain of HRV recovery were also improved in BFR-W after training (p<0.05), with no interaction effect (p>0.05). Additionally, in BFR-W group, RMSSD60s values were improved in some moments after training (p<0.05). Therefore, this study demonstrates that a 6-week walking training with BFR improved cardiac autonomic responses on the onset and recovery of exercise.

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.…”

“…In young adults, no significant changes were observed in HR and BP following 3 weeks of leg press, knee flexion and knee extension training with BFR (20% 1RM; 2 sets of 10 reps; 3x/weeks; BFRP 20% above systolic BP) (Kim et al, 2009). In contrast, Junior et al showed a reduction in HR of healthy males following 6 weeks of BFR walking training (6 km•h −1 , 5% grade; 5 sets of 3 min; 3x/week; BFRP between 80 and 100 mmHg) (Junior et al, 2019). Similarly, reduced mean BP was observed in healthy young individuals following 4 weeks of BFR handgrip training (30 contractions per minute at 30% MVC; 3x/week; BFRP between 75 and 150% of systolic blood pressure) (Crisafulli et al, 2018) (Kacin and Strazar, 2011).…”

“…BFR training has been reported to improve arterial compliance and stiffness, as well as increase arterial diameter ( Ozaki et al, 2011 ; Hunt et al, 2013 ). During BFR, there is an accumulation of metabolites that culminates in elevated metabolic stress as well as metaboreflex-induced increases in heart rate, blood pressure, and cardiac sympathetic modulation ( Junior et al, 2019 ; Cristina-Oliveira et al, 2020 ). In the next sections, we discuss the main cardiovascular adaptations related to BFR training and how such adaptations could impact BFRP prescription during BFR training intervention.…”

“…In contrast, Junior et al showed a reduction in HR of healthy males following 6 weeks of BFR walking training (6 km⋅h –1 , 5% grade; 5 sets of 3 min; 3x/week; BFRP between 80 and 100 mmHg) ( Junior et al, 2019 ). Similarly, reduced mean BP was observed in healthy young individuals following 4 weeks of BFR handgrip training (30 contractions per minute at 30% MVC; 3x/week; BFRP between 75 and 150% of systolic blood pressure) ( Crisafulli et al, 2018 ) and 8 weeks of BFR elbow flexion training (30% 1RM; 5 sets of 20 reps; 5x/week; BFRP 65 of 130% of SBP) ( Zhao et al, 2020 ).…”

“…After cuff deflation at the end of BFR exercise, ischemic reperfusion causes shear stress ( Patterson and Ferguson, 2010 ; Hunt et al, 2013 ) and metabolic stimuli, which may affect vessel adaptations over time ( Green et al, 2011 ). Also, BFR training can increase exercise pressor reflex, which is a reflex-mediated cardiovascular response, via engagement of the muscle metaboreflex ( Sundblad et al, 2018 ; Cristina-Oliveira et al, 2020 ) and cardiac autonomic changes ( Junior et al, 2019 ). Additionally, systolic blood pressure is directly proportional to BFRP ( Loenneke et al, 2015 ; Bezerra de Morais et al, 2017 ), and studies showed SBP to reduce over weeks of BFR training ( Cezar et al, 2016 ; Kambič et al, 2019 ).…”