Blood Flow Restriction Exercise Research Articles

PRESCRIBING BLOOD FLOW-RESTRICTED CYCLING USING RPE BALANCES THE PHYSIOLOGICAL AND PERCEPTUAL DEMANDS IN HEALTHY ADULTS

INTRODUCTION Aerobic exercise is commonly prescribed using fixed heart rates or power/speed. These methods may not be suitable when incorporating blood flow restriction (BFR), as this technique can influence these measurements. Prescribing exercise via perception of exertion (RPE), which reflects overall psychophysiological stress, may present an alternative to overcome these issues. Aim: Describe physiological and perceptual responses during fixed-power and fixed-RPE cycling performed with blood flow restriction (BFR_{PWR} and BFR_{RPE}) and without (CON_{PWR} and CON_{RPE}). METHODS Following baseline testing, twelve active males cycled for ten minutes under four conditions. CON_{PWR} was performed first, then the remaining conditions in a randomised and counterbalanced order. BFR_{PWR} and CON_{PWR} were performed at the power equivalent to the first ventilatory threshold (161±38W). CON_{RPE} and BFR_{RPE} were prescribed at the RPE reported during CON_{PWR}. Continuous ventilatory and heart rate measurements were recorded as two-minute averages. Subjective RPE, effort, muscular discomfort, and cuff pain were recorded every two minutes. Blood lactate was measured pre-exercise, post-exercise, and two-minutes post-exercise. RESULTS BFR_{PWR} resulted in the greatest physiological and perceptual responses among all conditions. Power output was lower during BFR_{RPE} (119±48W) than CON_{RPE} (139±47W). Oxygen consumption during BFR_{RPE} (20.8±5.1mL·kg-1·min-1) was lower than CON_{PWR} (25.3±6.0mL·kg-1·min-1, p<0.001) and CON_{RPE} (22.3±5.9mL·kg-1·min-1, p=0.007). Heart rate during CON_{PWR} (143±22beats·min-1) was greater than BFR_{RPE} (133±26beats·min-1, p<0.001) and CON_{RPE} (131±25beats·min-1, p<0.001). Muscular discomfort was not different between BFR_{RPE} (2.5±1.3au) and CON_{PWR}(2.3±1.5au), yet both were greater than CON_{RPE} (p<0.001, 1.8±1.5au). Cuff pain was greater during BFR_{PWR} (3.3±1.7au) than BFR_{RPE} (2.2±1.1au, p<0001). Blood lactate was greater during fixed-power (4.9±3.5mmol·L-1) compared to fixed-RPE trials (3.6±2.7mmol·L-1, p<0.001). CONCLUSIONS BFR_{RPE} caused less discomfort and pain than BFR_{PWR} without compromising physiological stress compared to CON_{RPE}. BFR_{RPE} should be considered when high mechanical loads are contraindicated, or discomfort/pain is undesirable. These findings improve our understanding of aerobic BFR exercise prescription to healthy adults.

Effects of Blood Flow Restricted Resistance Exercise on Recovery Blood Flow under Various Environmental Temperature Conditions

OBJECTIVES This study examines the impact of blood flow restriction (BFR) resistance exercise on blood flow across varying environmental temperatures, aiming to understand the physiological responses, exercise function, and recovery process affected by temperature changes.METHODS Seven healthy males (age: 26.4±1.7 years, weight: 72.7±6.8 kg, height: 174.5±2.0 cm) participated in biceps brachii exercises with and without BFR under low (10°C/25% humidity), moderate (25°C/50% humidity), and high (40°C/50% humidity) environmental conditions. Each participant completed six sessions of exercise across these conditions to assess the recovery phase blood flow changes. Blood flow measurements were taken during the recovery phase for analysis.RESULTS Blood flow significantly increased in high-temperature conditions, independent of BFR application, showing notable differences compared to low-temperature conditions (<i>p</i><.05).CONCLUSIONS Environmental temperature significantly affects blood flow changes during BFR resistance exercise, with increased blood flow in high temperatures indicating a physiological adaptation to thermal stress. This suggests the need to consider environmental temperatures in optimizing BFR exercise protocols.

Acute hypoalgesic, neurophysiological and perceptual responses to low-load blood flow restriction exercise and high-load resistance exercise.

This study compared the acute hypoalgesic and neurophysiological responses to low-load resistance exercise with and without blood flow restriction (BFR), and free-flow, high-load exercise. Participants performed four experimental conditions where they completed baseline measures of pain pressure threshold (PPT), maximum voluntary force (MVF) with peripheral nerve stimulation to determine central and peripheral fatigue. Corticospinal excitability (CSE), corticospinal inhibition and short interval intracortical inhibition (SICI) were estimated with transcranial magnetic stimulation. Participants then performed low-load leg press exercise at 30% of one-repetition maximum (LL); low-load leg press with BFR at 40% (BFR40) or 80% (BFR80) of limb occlusion pressure; or high-load leg press of four sets of 10 repetitions at 70% one-repetition maximum (HL). Measurements were repeated at 5, 45min and 24h post-exercise. There were no differences in CSE or SICI between conditions (all P>0.05); however, corticospinal inhibition was reduced to a greater extent (11%-14%) in all low-load conditions compared to HL (P<0.005). PPTs were 12%-16% greater at 5min post-exercise in BFR40, BFR80 and HL compared to LL (P≤0.016). Neuromuscular fatigue displayed no clear difference in the magnitude or time course between conditions (all P>0.05). In summary, low-load BFR resistance exercise does not induce different acute neurophysiological responses to low-load, free-flow exercise but it does promote a greater degree of hypoalgesia and reduces corticospinal inhibition more than high-load exercise, making it a useful rehabilitation tool. The changes in neurophysiology following exercise were not related to changes in PPT.

Concerns about the application of resistance exercise with blood-flow restriction and thrombosis risk in hemodialysis patients

BackgroundHemodialysis (HD) per se is a risk factor for thrombosis. Considering the growing body of evidence on blood-flow restriction (BFR) exercise in HD patients, identification of possible risk factors related to the prothrombotic agent D-dimer is required for the safety and feasibility of this training model. The aim of the present study was to identify risk factors associated with higher D-dimer levels and to determine the acute effect of resistance exercise (RE) with BFR on this molecule. MethodsTwo hundred and six HD patients volunteered for this study (all with a glomerular filtration rate of <15 mL/min/1.73 m2). The RE + BFR session consisted of 50% arterial occlusion pressure during 50 min sessions of HD (intradialytic exercise). RE repetitions included concentric and eccentric lifting phases (each lasting 2 s) and were supervised by a strength and conditioning specialist. ResultsSeveral variables were associated with elevated levels of D-dimer, including higher blood glucose, citrate use, recent cardiovascular events, recent intercurrents, higher inflammatory status, catheter as vascular access, older patients (>70 years old), and HD vintage. Furthermore, RE + BFR significantly increases D-dimer after 4 h. Patients with borderline baseline D-dimer levels (400–490 ng/mL) displayed increased risk of elevating D-dimer over the normal range (>500 ng/mL). ConclusionThese results identified factors associated with a heightened pro-thrombotic state and may assist in the screening process for HD patients who wish to undergo RE + BFR. D-dimer and/or other fibrinolysis factors should be assessed at baseline and throughout the protocol as a precautionary measure to maximize safety during RE + BFR.

Refining safety considerations for intradialytic blood flow restriction exercise. Commentary on “Concerns on the application of blood-flow restriction resistance exercise and thrombosis risk in hemodialysis patients”

Refining safety considerations for intradialytic blood flow restriction exercise. Commentary on “Concerns on the application of blood-flow restriction resistance exercise and thrombosis risk in hemodialysis patients”

The Clinical Effects of Pharmacotherapy Combined with Blood Flow Restriction and Isometric Exercise Training in Rehabilitating Patients with Heart Failure with Reduced Ejection Fraction.

Heart failure with reduced ejection fraction (HFrEF) is associated with reduced cardiac function and impaired quality of life. Blood flow restriction (BFR) training is emerging as a potential adjunctive therapy. This study aimed at evaluating the efficacy of combination of BFR and isometric exercises on cardiac function, functional status, and quality of life in HFrEF patients. Totally 44 patients with HFrEF were equally divided into a control group and a combined treatment group. Both groups received standard pharmacotherapy and upper limb exercise, with the combined group also undergoing BFR and isometric exercise training. We assessed demographic and clinical characteristics, New York Heart Association (NYHA) functional classification, cardiac function parameters, serum Brain Natriuretic Peptide levels, physical capacity via the 6-minute walking test, and quality of life using the Heart Failure Questionnaire (Minnesota Living with Heart Failure Questionnaire). Post-treatment, the combined group significantly improved in NYHA classification (p = 0.012), with more patients shifting to a better class. Cardiac function improved in both groups, with the combined group showing a greater increase in mean left ventricular ejection fractions (p < 0.001), and reductions in left ventricular end-diastolic and end-systolic diameters (p < 0.05). The addition of BFR training to standard pharmacotherapy with upper limb exercise in HFrEF patients led to significant enhancements in cardiac function, functional status, and quality of life. These findings support the integration of BFR training into conventional HFrEF treatment regimens to maximize patient recovery outcomes.

Idiosyncratic bone responses to blood flow restriction exercise: new insights and future directions.

Applying blood flow restriction (BFR) during low load exercise induces beneficial adaptations of the myotendinous and neuromuscular system. Despite the low mechanical tension, BFR exercise facilitates a localized hypoxic environment and increase in metabolic stress, widely regarded as the primary stimulus for tissue adaptations. First evidence indicates that low load BFR exercise is effective in promoting an osteogenic response in bone, although this has previously been postulated to adapt primarily during high-impact weight-bearing exercise. Besides studies investigating the acute response of bone biomarkers following BFR exercise, first long-term trials demonstrate beneficial adaptations in bone in both healthy and clinical populations. Despite the increasing number of studies, the physiological mechanisms are largely unknown. Moreover, heterogeneity in methodological approaches such as biomarkers of bone metabolism measured, participant and study characteristics, and time-course of measurement render it difficult to formulate accurate conclusions. Furthermore, incongruity in the methods of BFR application (e.g., cuff pressure) limits the comparability of datasets and thus hinders generalizability of study findings. Appropriate use of biomarkers, effective BFR application and befitting study design has the potential to progress knowledge on the acute and chronic response of bone to BFR exercise and contribute toward the development of a novel strategy to protect or enhance bone health. Therefore, the purpose of the present synthesis review is to: i) evaluate current mechanistic evidence; ii) discuss and offer explanations for similar and contrasting data findings; and iii) create a methodological framework for future mechanistic and applied research.

Blood Flow Restriction Exercises (BFR) an Effect on Strength Rehabilitation and Muscle Atrophy for Patients with Multiple Femur Fractures Aged 40-50 Years

The present study examined the effect of rehabilitation exercises with BFR in improving muscle strength, thigh muscle hypertrophy, and knee joint flexibility for those with double fractures in the lower body. Methods: 6 volunteer subjects (average age 44 (40–50) years) were randomized into one group that trained in restriction of blood flow period eight weeks. Participants were familiar with all testing and exercise protocols before starting the study. Rehabilitation exercises with BFR were done before and after—form for each player to record the sequence measurements. Quadriceps circumference measurement (cm), the range of motion of the knee joint, and Quadriceps muscle strength measurement were performed on the participants. Independent samples t-test was used to compare the scores obtained from the measurements according to categorical variables. The significance level was determined as P 0.05. Results: Thigh circumference (cm) There was a significant increase in thigh circumference from before the experiment (41.17 cm) to after the investigation (45.33 cm) (p&amp;lt;0,001). There's a remarkable development in post-test measurements (13.97 kg), (p&amp;lt;0,000) compared to pre-test measurements (8.83 kg), indicating an improvement in quadriceps strength. Hamstring strength (kg) in the post-test measurement (10.17 kg) demonstrated a remarkable development compared to the pre-test measurement (7.5 kg) (p&amp;lt;0,003). The post-test measurement (24.5 degrees) showed significant development compared to the pre-test measurement (60.83 degrees) (p&amp;lt;0,000), suggesting an improvement in the range of motion of the flexed knee joint. In conclusion, it shows that blood flow restriction is a safe and effective treatment for people with multiple fractures.

Short-Term Impact of Low-Intensity Exercise with Blood Flow Restriction on Mild Knee Osteoarthritis in Older Adults: A Pilot Study

This pilot study aimed to investigate the immediate impact of low-intensity exercises with blood flow restriction (BFR) on older adults with knee osteoarthritis (KOA). Fifteen patients with KOA who were over 50 years old, participated and underwent low-intensity resistance knee exercises at 30% of their one-repetition maximum with BFR three times/week for two weeks. Pre- and post-exercise assessments included pain levels, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores, isokinetic knee strength, lower extremity muscle volume (via leg circumference and muscle thickness), functional performance tests (timed up-and-go [TUG] and sit-to-stand [STS]), skeletal muscle index (SMI) using bioelectrical impedance analysis, and handgrip strength (HGS). Post-exercise, there was a significant reduction in pain. WOMAC scores showed significant improvements across all three domains: pain, stiffness, and physical function. In the TUG and STS tests, completion times were significantly reduced. Thigh and calf circumferences, as well as thigh muscle thickness significantly increased after exercise. Post-exercise SMI and HGS also significantly increased. However, isokinetic knee strength did not show significant changes. In conclusion, low-intensity BFR exercises provide immediate benefits in symptoms and physical performance for patients with KOA, potentially inducing local and systemic muscle mass increase, even after a short-term intervention.

Efficacy of Low Blood Flow Restricted Exercise on Increasing Muscle Strength in Patients with Knee Osteoarthritis Comparing with Conventional Strength Training

Background: The prevalence of OA knee is diagnosed with radiographic features 15% of patients were symptomaticin one study. OA affects nearly 6% of adults. Female sex is more common. 13% of females and 10% of male in 60years are affected with OA and in 70 years of population rises to 40%.Purpose: To find the efficacy of low blood flow restricted resistance exercise on increasing muscle strength inpatients with knee OA compared with conventional strength training using NPRS for pain and knee ROM.Materials and Methods: A total of 60 subjects were assigned in this study. The NPRS and knee ROM were usedto calculate pre-and post-test results. Each session included three sets of five repetitions with a ten-second hold inbetween. The tables were tabulated and statistically evaluated.The entire process was conducted from November2022 to April 2023.Result: According to the statistical analysis, both groups had a statistically significant improvement between theirpre and post-exercise values (p&lt;0.0001). There is also a significant variation in post-exercise results between thetwo groups (p&lt;0.0001), indicating that blood flow restriction with exercises is more effective than conventionalstrength training with exercises.Conclusion: Blood flow restriction has been shown to be more effective than conventional strength training atrelieving pain and increasing knee ROM.

Investigating the Effects of Blood Flow Restriction Exercises on Strength and Cross Section Area of Hamstring Muscles and Tendons: A Case Report

Introduction: Hamstring injuries are one of the most common tendon injuries, especially in sports that require running and jumping. A comprehensive training program can help athletes to prevent this injury. Among suggested exercises, the Nordic eccentric training can reduce the injury rate by up to 50%; however, it is a high-load exercise that cannot be prescribed in the first stages of rehabilitation. Here, we describe a football player who used low-load resistance exercise with blood flow restriction as an alternative method to strengthen their hamstring after nine months of anterior cruciate ligament reconstruction surgery&#x0D; Case Description: A 19-year-old non-professional footballer with a body mass index of 22.18 kg/cm2 was invited to participate in this study. The variables examined included strength and cross-sectional area of the hamstring muscles (mean and maximum strength) and the crosssectional area of the hamstring tendons at their origin. The treatment program included a seated hamstring curl with a load of 30% 1 RM with blood flow restriction for four weeks (thrice a week).&#x0D; Results: The hamstring muscle strength improved by 6.54%, and the cross-sectional area of the muscles and tendons changed as follows: Semimembranosus (tendon=0.07%, muscle=2.57%), semitendinosus (tendon=0.00%, muscle=-4.04%), and biceps-femoris (tendon=5.5%, muscle=4.34%).&#x0D; Conclusion: Low load resistance training with blood flow restriction in this athlete improved the strength and cross-sectional area of the hamstring muscles as well as the cross-sectional area of the tendons. The changes observed in tendon, and muscle cross-sectional areas were more prominent for biceps-femoris. This case showed that a training program with blood flow restriction may be a good alternative for people who cannot tolerate high-load exercises in the early stages of their rehabilitation. Doing more extensive studies with more cases and a control group in the future can help our knowledge in giving the best exercise prescription to our patients.

Muscular stress is equal when resistance exercise with blood flow restriction is matched in total work volume: A cross-sectional, cross-over study.

We compared muscular metabolic stress during exercise performed at multiple intensities, from very low to moderate, with blood flow restriction (BFR) adjusted by the same work volume. Twenty-five healthy young adults performed unilateral plantar flexion at 1 repetition/2 s in a magnetic resonance system. The BFR exercise protocols were as follows: (A) exercise with 10% of one repetition maximum (1-RM) for 360 s, (B) 15% 1-RM for 240 s, (C) 20% 1-RM for 180 s, (D) 30% 1-RM for 120 s, and (E) 40% 1-RM for 90 s. All protocols had the same total work volume (load × repetitions = 1800). A high-intensity protocol at 65% 1-RM without BFR (60 s) was also performed for comparison. We used 31 P-magnetic resonance spectroscopy to evaluate the muscular metabolic stress in the subjects' calf muscle, defined as decreases in phosphocreatine and intramuscular pH. The phosphocreatine depletion (A: 15.6 ± 0.7, B: 14.8 ± 0.8, C: 15.2 ± 0.6, D: 14.3 ± 0.6, E: 10.9 ± 0.5 mM; no significant difference [ns]) and the intramuscular pH decrease (A: 6.82 ± 0.02, B: 6.84 ± 0.01, C: 6.83 ± 0.02, D: 6.83 ± 0.02, E: 6.77 ± 0.02; ns) at the end of each exercise were similar and greater than those produced by the 65% 1-RM without BFR. If the total work volumes are equal, the metabolic stress in exercising muscle may reach similar levels at the end of exercise with BFR and could provide similar successful training effects.

Safety and efficacy of blood flow restriction exercise in individuals with neurological disorders: A systematic review.

This systematic review evaluated the safety and efficacy of blood flow restriction exercise (BFRE) on skeletal muscle size, strength, and functional performance in individuals with neurological disorders (ND). A literature search was performed in PubMed, CINAHL, and Embase. Two researchers independently assessed eligibility and performed data extraction and quality assessments. Study populations with ND, BFRE as intervention modality, outcome measures related to safety or efficacy. Out of 443 studies identified, 16 were deemed eligible for review. Three studies examined the efficacy and safety of BFRE, one study focused on efficacy results, and 12 studies investigated safety. Disease populations included spinal cord injury (SCI), inclusion body myositis (sIBM), multiple sclerosis (MS), Parkinson's disease (PD), and stroke. A moderate-to-high risk of bias was presented in the quality assessment. Five studies reported safety concerns, including acutely elevated pain and rating of perceived exertion levels, severe fatigue, muscle soreness, and cases of autonomic dysreflexia. Two RCTs reported a significant between-group difference in physical function outcomes, and two RCTs reported neuromuscular adaptations. BFRE seems to be a potentially safe and effective training modality in individuals with ND. However, the results should be interpreted cautiously due to limited quality and number of studies, small sample sizes, and a general lack of heterogeneity within and between the examined patient cohorts.

The Effectiveness of Blood Flow Restriction Technique Combined with Low-Resistance Exercise in the Postoperative Rehabilitation of Patients Following Knee Surgery: A Narrative Review and Update of Evidence-Based Physiotherapy Practice

&lt;b&gt;Background:&lt;/b&gt; Blood flow restriction (BFR) therapy has emerged as a promising rehabilitation approach after knee surgery. The technique involves the use of a tourniquet or cuff to limit blood flow to the affected limb during low-resistance exercise, which creates a hypoxic environment thought to stimulate muscle growth and improve muscle function. &lt;b&gt;Objective:&lt;/b&gt; Our scoping review aims to examine the current literature on the effectiveness of BFR combined with low-resistance exercise on rehabilitation after knee surgery. &lt;b&gt;Method: &lt;/b&gt;The Google Scholar, PubMed, and PEDro databases were searched using relevant key-words. Studies that met the inclusion criteria were selected for analysis. The data from the selected studies were analyzed, categorized, and summarized to provide an overview of the findings. &lt;b&gt;Results:&lt;/b&gt; In total, 12 studies met the inclusion criteria and were included in the review. Outcomes such as pain, strength, and range of motion were assessed. &lt;b&gt;Conclusion: &lt;/b&gt;The results suggest that BFR and low-resistance exercise can be effective in improving patient outcomes following knee surgery. However, the heterogeneity of the studies made it difficult to determine the most effective approach. Further research is needed to identify the optimal dosage, frequency, and duration of BFR and low-resistance exercise for knee surgery rehabilitation.

Comparing the efficacy of low-load resistance exercise combined with blood flow restriction versus conventional-load resistance exercise in Chinese community-dwelling older people with sarcopenic obesity: a study protocol for a randomised controlled trial

IntroductionSarcopenic obesity (SO) is characterised by decreased muscle mass, diminished muscle strength and/or reduced physical performance and a high percentage of body fat (PBF). Conventional-load resistance exercise (CRE) may be difficult for older people with SO owing to their declining physical functions. Low-load resistance exercise (LRE) combined with blood flow restriction (BFR; LRE-BFR) is a viable alternative to CRE for improving muscle mass and strength and potential exercise mode for managing SO. This study has two objectives: (1) to comprehensively evaluate the efficacy of CRE and LRE-BFR in improving body composition, muscle strength, physical performance, haematological parameters, cardiovascular disease (CVD) risk factors and quality of life and (2) to compare the efficacy of CRE and LRE-BFR and explore their potential mechanisms.Methods and analysisThis work is a 12-week assessor-blinded randomised clinical trial that will be conducted thrice a week. Sarcopenia will be defined using the Asian Working Group for Sarcopenia 2019, and obesity will be determined using the criteria developed by the World Health Organization. Community-dwelling older people aged ≥ 65 years will be screened as the participants using inclusion and exclusion criteria. A total of 33 participants will be randomised into a CRE group (n = 11), an LRE-BFR group (n = 11) and a control group that will be given only health education (n = 11). The primary outcomes will be knee extensor strength and PBF, and the secondary outcomes will be body composition, anthropometric measurements, muscle strength of upper limbs, physical performance, haematological parameters, CVD risk factors and quality of life. The outcomes will be measured at the baseline (week 0), end of the intervention (week 12) and follow up (week 24). All the collected data will be analysed following the intention-to-treat principle.Ethics and disseminationThe Ethics Research Committee has approved this study (approval No. CMEC-2022-KT-51). Changes or developments in this study will be reported at www.chictr.org.cn.Trial registrationChiCTR2300067296 (3 January 2023).

Physiological and clinical effects of low-intensity blood-flow restricted resistance exercise compared to standard rehabilitation in adults with knee osteoarthritis–Protocol for a randomized controlled trial

Introduction Osteoarthritis (OA) is a common disease with high socioeconomical costs. In Denmark, standard rehabilitation (SR) consists of a combination of patient education and supervised physical exercise involving a standardized neuromuscular training program. As an evidence-based alternative, high–load (&gt;70% 1RM) resistance training (HIRT) has shown positive rehabilitation effects in knee-OA but may not be tolerated in all patients (~25%) due to knee joint pain. However, low-load resistance training (20–40% 1RM) with concurrent partial blood-flow restriction (BFR) appears to produce effects similar to HIRT yet involving reduced joint pain during and after exercise. The aim is to examine the effect of low-load BFR training compared to SR on pain, thigh muscle mass and muscle function in adults with knee-OA. We hypothesize that 12 weeks of BFR will lead to superior improvements in pain, muscle mass and mechanical muscle function compared to SR. Methods and analysis 90 participants diagnosed with radiographic knee-OA will be randomized to either BFR or SR twice a week for 12 weeks. BFR will consist of two selected lower limb strength exercises performed with an inflated pneumatic occlusion cuff. Intervention procedures in SR consist of a full 8 weeks GLA:D course followed by 4 weeks of team group training. Primary outcome variable is the change in KOOS-Pain subscale from baseline to 12 weeks. Secondary outcome variables are changes in pain sensitivity, functional performance, muscle mass and mechanical muscle function. Intention-to-treat and per-protocol analyses will be conducted. One-way analysis of variance will be performed to evaluate between-group changes. Pre-to-post intervention comparisons will be analyzed using a mixed linear model. Regression analysis will be performed to evaluate potential associations between selected outcome variables.

Current Implementation and Barriers to Using Blood Flow Restriction Training: Insights From a Survey of Allied Health Practitioners.

Scott, BR, Marston, KJ, Owens, J, Rolnick, N, and Patterson, SD. Current implementation and barriers to using blood flow restriction training: Insights from a survey of allied health practitioners. J Strength Cond Res 38(3): 481-490, 2024-This study investigated the use of blood flow restriction (BFR) exercise by practitioners working specifically with clinical or older populations, and the barriers preventing some practitioners from prescribing BFR. An online survey was disseminated globally to allied health practitioners, with data from 397 responders included in analyses. Responders who had prescribed BFR exercise ( n = 308) completed questions about how they implement this technique. Those who had not prescribed BFR exercise ( n = 89) provided information on barriers to using this technique, and a subset of these responders ( n = 22) completed a follow-up survey to investigate how these barriers could be alleviated. Most practitioners prescribe BFR exercise for musculoskeletal rehabilitation clients (91.6%), with the BFR cuff pressure typically relative to arterial occlusion pressure (81.1%) and implemented with resistance (96.8%) or aerobic exercise (42.9%). Most practitioners screen for contraindications (68.2%), although minor side effects, including muscle soreness (65.8%), are common. The main barriers preventing some practitioners from using BFR are lack of equipment (60.2%), insufficient education (55.7%), and safety concerns (31.8%). Suggestions to alleviate these barriers included developing educational resources about the safe application and benefits of BFR exercise ( n = 20) that are affordable ( n = 3) and convenient ( n = 4). These results indicate that BFR prescription for clinical and older cohorts mainly conforms with current guidelines, which is important considering the potentially increased risk for adverse events in these cohorts. However, barriers still prevent broader utility of BFR training, although some may be alleviated through well-developed educational offerings to train practitioners in using BFR exercise.

Enhanced Pain Relief and Muscle Growth in Individuals with Low Back Instability: The Impact of Blood Flow Restriction Exercise during Sit to Stand Movements.

BACKGROUND Blood flow restriction exercise (BFRE) improves muscle strength at a relatively low intensity by temporarily restricting blood flow. This study compared pain and quadriceps muscle mass (QMM) in 40 patients with lower back pain (LBP) undertaking sit-to-stand (STS) exercise with and without blood flow restriction. MATERIAL AND METHODS Forty adults were divided into 2 groups, and the experimental group (n=20) performed an STS exercise with BFRE, and the control group (n=20) performed an STS exercise without BFRE. Blood pressure, including systolic blood pressure (SBP) and diastolic blood pressure (DBP), was measured using a portable blood pressure monitor. Saturation of percutaneous oxygen (SpO2) was measured using oxygen saturation. Pain was measured using the visual analog scale (VAS) and the Oswestry disability index (ODI). QMM was assessed using ultrasonography. RESULTS Data were analyzed using paired and independent t tests. SBP (P=.000), DBP (P=.004), and SpO2 (P=.001) were significantly different in the experimental group, both before and during the intervention. The VAS scores showed a statistically significant difference in the post-test (P=.003) and rate of change (P=.009) between the groups. The ODI scores showed statistically significant differences in the post-test (P=.000) and rate of change (P=.001) comparison between the groups. The rate of change in QMM, including the rectus femoris (P=.000), vastus intermedius (P=.004), vastus medialis (P=.001), and vastus lateralis (P=.014), increased significantly in the experimental group compared to that in the control group. CONCLUSIONS This study demonstrates that the additive effect of BFRE on pain relief and QMM increase, thus contributing to existing knowledge about therapeutic exercise for the effective management of LBP.

No Differences in Exercise Performance, Perceptual Response, or Safety Were Observed Among 3 Blood Flow Restriction Devices

To compare 3 separate blood flow restriction (BFR) systems in their capacity to reduce repetitions to failure, impact perceptual responses, and cause adverse events during a low-load free-flow exercise. The study included healthy subjects aged 18 years or older who presented to an ambulatory-care sports medicine clinic. On day 1, participants' demographic characteristics and anthropomorphic measurements were recorded. Each participant performed dumbbell biceps curl repetitions to failure using 20% of his or her 1-repetition maximum weight with each arm. Participants were exposed to 3 different tourniquet systems for familiarization. On day 2, each participant's arm was randomized to a cuff system, and the participant performed 2 sets of biceps curl repetitions to failure with the cuff inflated. Repetitions to failure, rating of perceived effort (RPE), rating of perceived discomfort, and pulse oxygenation levels were recorded after each set. On day 3, participants completed a survey of their perceived delayed-onset muscle soreness. The final analysis was performed on 42 arms, with 14 limbs per system. The study population had a mean age of 28.7 ± 2.4 years and a mean body mass index of 24.9 ± 4.3. All 3 systems successfully reduced repetitions to failure compared with unrestricted low-load exercise from baseline to BFR set 1 and from baseline to BFR set 2. There were no significant between-group differences among BFR systems regarding the number of repetitions to failure performed at baseline versus BFR set 1 or BFR set 2. The Delfi Personalized Tourniquet System (PTS) cohort had the greatest reductions in repetitions to failure from BFR set 1 to BFR set 2 (P= .002) and reported the highest RPE after set 2 (P= .025). The Delfi PTS, SmartCuffs Pro, and BStrong BFR systems were each safe and were able to significantly reduce repetitions to failure compared with a low-load free-flow condition when used in a BFR exercise protocol. The Delfi PTS system may produce a higher RPE with prolonged use in comparison to the other systems. Level II, prospective cohort study.

Effects of blood-flow restricted exercise versus conventional resistance training in musculoskeletal disorders—a systematic review and meta-analysis

ObjectiveTo compare the effect of low-load blood flow restricted resistance training (BFR-RT) versus high-load resistance training (HL-RT) on muscle strength, muscle mass, physical function, patient-reported outcomes, and adherence to training in clinical musculoskeletal populations.Data sourcesWeb of Science, Cochrane Central, Medline, Embase, SportDiscus was searched on the 30th May 2022.Review methodsThis study was conducted as a systematic review and meta-analysis. Randomized Controlled Trials (RCTs) were included if they (i) included patients, (ii) comprised of a BFR-RT intervention protocol and a group who performed HL-RT (≥ 70%1RM) for at least eight exercise sessions, and (iii) involved at least 1 exercise that targeted the lower limbs. The Cochrane Risk of Bias tool was used to evaluate the risk of bias. The meta-analyses were performed using a random effects model with an adjustment to the confidence interval.ResultsSeven RCTs comprising 303 participants (BFR-RT: n = 151; HL-RT: n = 152) were identified. HL-RT and BFR-RT showed similar gains in dynamic (1-10RM) knee extensor strength and leg press strength, quadriceps cross sectional area, sit-to-stand performance, and patient reported pain and function. There was a moderate effect favoring BFR-RT for increasing maximal isometric knee extensor strength. The grading of certainty in evidence was low-to-very low for all outcome variables.ConclusionThis systematic review and meta-analysis extends our current knowledge about BFR-RT and HL-RT as equally effective exercise methods for inducing gains in maximal muscle strength in healthy populations, by now also comprising patients suffering from various clinical musculoskeletal conditions. The certainty in the estimates was low-to-very low, prompting the inclusion of future higher-quality trials.Trial registrationPROSPERO ID (CRD42022337173). Registered June 18th 2022.