Peripheral and Central Blood Pressure Response to Handgrip Exercise Coupled with Blood Flow Restriction

Abstract

Low intensity exercise coupled with blood flow restriction (BFR) produces comparable strength gains and skeletal muscle hypertrophy, compared to non-BFR training at higher intensities. However, the cardiovascular response (e.g., blood pressure-BP) to this type of exercise remains controversial. PURPOSE: To examine peripheral and central BP responses to low and high-intensity, unilateral handgrip exercise performed with and without BFR. METHODS: Eight college-aged males (Age=24±5 yrs; BMI=30±7 kg/m2, handgrip max voluntary contraction-MVC=52±8 kg) underwent three 5-minute bouts (counter-balanced, 10 mins rest) of rhythmic handgrip (1–2 sec duty cycle, 20 squeezes/min) performed at a low (40% MVC) and high-intensity (60% MVC) with and without proximal occlusion (80-100 mmHg, 50-80% arterial occlusion assessed via radial artery Doppler-ultrasound). Peripheral BP’s (brachial artery) were obtained using the oscillometric method, and a proprietary transfer function was applied to the pulse waveform to estimate central aortic BP’s [systolic, diastolic, mean arterial pressure (MAP) and rate-pressure product (RPP=heart rate x systolic BP)]. RESULTS: Peripheral systolic and diastolic BP, MAP and RPP were greater than central pressures at BL (e.g., peripheral systolic BP=130±6 vs. central systolic BP=113±5 mmHg; P<0.001), and across each handgrip bout (P<0.05). Compared to BL, both peripheral and central MAP increased, with the greatest change occurring during high-intensity handgrip with BFR (+17±4, P<0.001). Similar findings were observed for peripheral and central systolic and diastolic BP, and RPP (e.g., central RPP at BL=7296±621, vs. 40% BFR=8217±612, vs. 60% with BFR=9441±686, vs. 60% without BFR=9237±629; P<0.001). CONCLUSION: These preliminary findings indicate that low intensity, unilateral handgrip exercise performed with BFR produces a comparable BP response (i.e., magnitude increase for MAP) as high intensity handgrip without BFR; however, RPP was greater during high intensity handgrip both with and without BFR, compared to low intensity with BFR.