Hemodynamic Responses to Low-Load Blood Flow Restriction and Unrestricted High-Load Resistance Exercise in Older Women

Abstract

Introduction: Blood flow restriction (BFR) during low-load resistance exercise increases muscle size similarly to high-load training, and may be an alternative to lifting heavy weights for older people at risk of sarcopenia. However, few studies have addressed the safety of such exercise in older people, or whether this is impacted by the actual exercises performed during training. This study aimed to compare the acute hemodynamic and perceptual responses during low-load BFR exercise to unrestricted low-load and high-load exercise in older women, and to determine whether these responses depend on the type of exercise performed.Methods: Fifteen older women (63–75 year) were assessed for maximal strength (1RM) in the leg press and leg extension. Participants then completed three protocols using these exercises in a randomized order: (1) low-load exercise (LL); (2) low-load exercise with BFR (LLBFR), and; (3) high-load exercise (HL). Blood pressure was assessed at baseline and after each set, and impedance cardiography measured cardiovascular function during trials. Rating of perceived exertion (RPE) and muscle soreness scores were obtained throughout trials.Results: Baseline hemodynamic values were consistent between trials. Systolic, diastolic, and mean arterial pressures were higher in LLBFR compared with HL and LL (p ≤ 0.021). The LL condition resulted in lower heart rate (p ≤ 0.002) and rate-pressure product (p ≤ 0.011) responses compared with LLBFR and HL. The leg press generally conferred greater hemodynamic and perceptual demands than the leg extension for all conditions (p ≤ 0.002). RPE was lower during LL compared with LLBFR and HL (p ≤ 0.008), and there were no between-condition differences in perceived muscle soreness.Conclusion: The blood pressure data indicate that LLBFR causes greater stress on the vasculature than LL and HL exercise, and that the leg press was generally more demanding than the leg extension. While additional cardiovascular measures were similar between LLBFR and HL conditions, caution should be advised when prescribing BFR exercise for individuals with compromised cardiac or vascular function. Nevertheless, LLBFR and HL exercise were perceived similarly, indicating that BFR training may be viable for healthy older people.

Blood Flow Restriction Resistance Exercise Improves Muscle Strength and Hemodynamics, but Not Vascular Function in Coronary Artery Disease Patients: A Pilot Randomized Controlled Trial

“…Thus it may be postulated that BFR using lower loads could promote better training adaptations compared to higher loads resistance training without occlusion (Hackney et al, 2012). Our acute hemodynamic response to exercise is in line with previous reports in healthy older men (Staunton et al, 2015) and women (Scott et al, 2018) using BFR-RT, despite lower increase in heart rate. This can be explained with the discrepancies between exercise modes.…”

Is there rationale for the cuff pressures prescribed for blood flow restriction exercise? A systematic review

“…Other populations included resistance‐trained adults, adults with musculoskeletal or soft tissue injuries, older adults, or adults with hypertension. There were far more studies (26 of 52) examining only male participants, 17,24,25,30,32‐38,41‐43,46,48,50‐59 compared with just 8 of 52 examining only female participants, 40,49,60‐65 leaving 18 studies examining both of these genders 8,19,20,39,44,45,47,66‐75 …”

“…Sixteen of the 52 included studies applied multiple different cuff pressures as a means of comparing acute responses or chronic adaptations to different applied pressures 17,20,31,32,36,39,43,44,48,54,67,68,70,72,73,75 . Among the remaining 36 studies using a single individualized pressure for their application of BFR, 13 studies used 80% AOP/LOP, 24,37,40,49,50,57,61,62,64‐66,71,74 7 studies used 60% AOP/LOP, 8,33,34,38,46,52,56 5 studies used 50% AOP/LOP, 25,41,42,59,60 4 studies used 100% AOP, 47,51,58,63 4 studies used 40% AOP/LOP, 19,30,45,69 and 3 studies used 30% AOP 35,53,55 . The technique and postures used to determine each of these individualized restriction pressures was similarly variable.…”

“…The posture in which assessment of occlusion pressure was conducted was not reported in 15 of the 52 included studies 24,30,32,34,35,43,47,49,51,53,58,61‐63,74 . Among those reporting participant posture during assessment, supine 17,36,37,40,42,48,50,54,56,57,59,64,65 or standing 8,19,20,31,41,44,46,52,69,70,72,73,75 were each chosen in 13 studies, and sitting was used in 11 studies 25,33,38,39,45,55,60,66‐68,71 …”

“…Seventeen of the included studies reported using a “standard sphygmomanometer” to apply BFR, rather than a dynamic pneumatically regulated system. The pattern of inflation was described in 43 out of the 52 included studies, with 38 studies using continuous inflation across the full duration of exercise (multiple sets and repetitions), 8,17,25,31‐36,38,39,42,43,46‐50,52‐54,56‐65,67‐71,74 only 3 studies using an intermittent inflation pattern whereby cuffs were deflated between sets of each exercise, 37,51,55 and 2 studies including both continuous and intermittent inflation patterns in separate experimental groups 24,40 …”