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Abstract

Background and objective Low-load exercise training with blood flow restriction (BFR) can increase muscle strength and may offer an effective clinical musculoskeletal (MSK) rehabilitation tool. The aim of this review was to systematically analyse the evidence regarding the effectiveness of this novel training modality in clinical MSK rehabilitation. Design This is a systematic review and meta-analysis of peer-reviewed literature examining BFR training in clinical MSK rehabilitation (Research Registry; researchregistry91). Data sources A literature search was conducted across SPORTDiscus (EBSCO), PubMed and Science Direct databases, including the reference lists of relevant papers. Two independent reviewers extracted study characteristics and MSK and functional outcome measures. Study quality and reporting was assessed using the Tool for the assEssment of Study qualiTy and reporting in EXercise. Eligibility Search results were limited to exercise training studies investigating BFR training in clinical MSK rehabilitation, published in a scientific peer-reviewed journal in English. Results Twenty studies were eligible, including ACL reconstruction (n=3), knee osteoarthritis (n=3), older adults at risk of sarcopenia (n=13) and patients with sporadic inclusion body myositis (n=1). Analysis of pooled data indicated low-load BFR training had a moderate effect on increasing strength (Hedges’ g=0.523, 95% CI 0.263 to 0.784, p<0.001), but was less effective than heavy-load training (Hedges’ g=0.674, 95% CI 0.296 to 1.052, p<0.001). Conclusion Compared with low-load training, low-load BFR training is more effective, tolerable and therefore a potential clinical rehabilitation tool. There is a need for the development of an individualised approach to training prescription to minimise patient risk and increase effectiveness.

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... BFRT involves light resistance training with the use of a restriction band proximally on the extremity to occlude venous blood outflow while maintaining arterial blood inflow. Light resistance training exerts mechanical stress on the muscles, and the use of a restriction band induces tissue hypoxia and stimulates anaerobic metabolism [43][44][45] . Research has demonstrated that BFRT can increase muscle strength, hypertrophy, and angiogenesis compared with unrestricted light resistance training, but less muscle is recruited compared with unrestricted heavy resistance training [43][44][45][46][47][48] . ...
... Light resistance training exerts mechanical stress on the muscles, and the use of a restriction band induces tissue hypoxia and stimulates anaerobic metabolism [43][44][45] . Research has demonstrated that BFRT can increase muscle strength, hypertrophy, and angiogenesis compared with unrestricted light resistance training, but less muscle is recruited compared with unrestricted heavy resistance training [43][44][45][46][47][48] . Although the biological mechanism is unknown, in theory, the combination of mechanical and metabolic stress is thought to facilitate cellular signaling pathways that lead to protein synthesis, fast-twitch muscle fiber recruitment, and stimulation of myogenic stem cells [43][44][45] . ...
... Research has demonstrated that BFRT can increase muscle strength, hypertrophy, and angiogenesis compared with unrestricted light resistance training, but less muscle is recruited compared with unrestricted heavy resistance training [43][44][45][46][47][48] . Although the biological mechanism is unknown, in theory, the combination of mechanical and metabolic stress is thought to facilitate cellular signaling pathways that lead to protein synthesis, fast-twitch muscle fiber recruitment, and stimulation of myogenic stem cells [43][44][45] . Because heavy resistance training is often contraindicated in the early stages of recovery, BFRT may be useful as a progressive rehabilitation method to promote the regeneration and healing of muscle 43,44 . ...
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» Calf strain is a common condition. In high-performance athletes, calf strain contributes to a substantial absence from competition. » Player age and history of a calf strain or other leg injury are the strongest risk factors for calf strain injury and reinjury. » Although the diagnosis is often clinical, magnetic resonance imaging and ultrasound are valuable to confirm the location of the strain and the grade of injury. » Nonoperative treatment is effective for most calf strain injuries. Operative management, although rarely indicated, may be appropriate for severe cases with grade-III rupture or complications. » Further investigation is necessary to elucidate the benefits of blood flow restriction therapy, deep water running, lower-body positive pressure therapy, platelet-rich plasma, and stem cell therapy for calf strain rehabilitation.
... However, due to pain and joint swelling, HRTS may be contraindicated, rendering patients suffering from ReA to search for alternative exercise methods. During the last decade, research on resistance training with loads as low as 20% of 1RM with concurrent partial or complete blood flow restriction to the exercising limb (low-load blood-flow restricted resistance training: BFR-RT) has consistently proven to promote skeletal muscle hypertrophy and increase muscle strength comparable to that of HRTS (Wernbom et al., 2008;Hughes et al., 2017;Grønfeldt et al., 2020). The ability to promote muscle morphological and muscle mechanical adaptations with low loads makes BFR-RT very interesting in clinical rehabilitation (Hughes et al., 2017;Jørgensen et al., 2018Jørgensen et al., , 2020Petersson et al., 2020). ...
... During the last decade, research on resistance training with loads as low as 20% of 1RM with concurrent partial or complete blood flow restriction to the exercising limb (low-load blood-flow restricted resistance training: BFR-RT) has consistently proven to promote skeletal muscle hypertrophy and increase muscle strength comparable to that of HRTS (Wernbom et al., 2008;Hughes et al., 2017;Grønfeldt et al., 2020). The ability to promote muscle morphological and muscle mechanical adaptations with low loads makes BFR-RT very interesting in clinical rehabilitation (Hughes et al., 2017;Jørgensen et al., 2018Jørgensen et al., , 2020Petersson et al., 2020). Furthermore, BFR-RT is safe in both cardiac and orthopedic patient populations and leads to greater reduction in knee joint swelling (Hughes et al., 2017Groennebaek et al., 2019;Patterson et al., 2019;Jørgensen et al., 2020). ...
... The ability to promote muscle morphological and muscle mechanical adaptations with low loads makes BFR-RT very interesting in clinical rehabilitation (Hughes et al., 2017;Jørgensen et al., 2018Jørgensen et al., , 2020Petersson et al., 2020). Furthermore, BFR-RT is safe in both cardiac and orthopedic patient populations and leads to greater reduction in knee joint swelling (Hughes et al., 2017Groennebaek et al., 2019;Patterson et al., 2019;Jørgensen et al., 2020). Results from our research group have demonstrated that patients can administer BFR exercises safely and correctly with minimal supervision (Petersson et al., 2020, Høghsholt et al., under review). ...
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Introduction: Reactive arthritis (ReA) is a chronic inflammatory disease usually caused by a preceding gastrointestinal or genitourinary bacterial infection. ReA usually occurs in the lower limbs causing joint pain and joint swelling. Physiotherapy-led exercise is recommended to prevent muscle atrophy. The purpose of this case report is to describe the outcome after 12 weeks of low-load blood flow restricted resistance training (BFR-RT) as a rehabilitation method for a young male suffering from ReA. Methods and materials: A 17-year-old male suffered from ReA in the both knee joints and the left hip joint. 36 months after the incident, he suffered from another ReA incident in his right knee. Non-steroid anti-inflammatory drugs and a new arthrocentesis added with corticosteroid injection was unsuccessful in treating the ReA. The patient performed 12 weeks of BFR-RT on the right lower limb with a low amount of supervision after the first week of training. Assessment of unilateral 30-sec chair stand test (u30-sec CST), low-thigh circumference above apex patella, The Knee Injury and Osteoarthritis Outcome Score (KOOS), The Forgotten Knee Joint Score (FJS), and Numeric Ranking Scale for pain (NRS) was performed at baseline and after 3,6,9, and 12 weeks of BFR-RT. Results: The patient completed all planned exercise sessions. u30-sec CST improved with 7 repetitions (reps) on the right limb and 5 reps on the left leg. Low-thigh circumference decreased 1.1 cm on the right leg and 1.0 on the left leg. KOOS symptoms, ADL, quality of life and FJS demonstrated a clinically relevant change on 10, 14 and 23 points. Conclusion: The present case study indicates that even with low amounts of supervision BFR-RT could increase functional performance, reduce knee joint swelling and improve key patient-reported outcome.
... Blood flow restriction training (BFRT) has been recognized as a critical tool in rehabilitation medicine, athletic and clinical populations. Although increases in muscle strength following high load resistance training (RT) appear significantly greater than low load RT with BFR, BFR induces similar hypertrophy and lower joint forces/stress with low load RT compared to high load traditional RT without BFR (Bagley et al., 2015;Scott et al., 2016;Hughes et al., 2017;Centner et al., 2019;Rolnick and Schoenfeld, 2020a). Besides the potential implementation of BFRT in clinical musculoskeletal rehabilitation (e.g., knee osteoarthritis, and anterior cruciate ligament reconstruction) (Hughes et al., 2017), clinicians prescribing BFRT are often faced with the BFRT paradox: while participation in regular BFRT (e.g., aerobic training, resistance training, and passively without exercise) is acknowledged to offer significant benefits in muscle mass and strength, it can possibly result in adverse events (e.g., numbness, nausea, hypertension, headache, venous thrombus, deterioration of ischemic heart disease, fainting, tingling, excessive pain, central retinal vein occlusion, and rhabdomyolysis) if applied inappropriately (Nakajima et al., 2006;Ozawa et al., 2015;Noto et al., 2017;Yasuda et al., 2017;Patterson and Brandner, 2018;de Queiros et al., 2021). ...
... Although increases in muscle strength following high load resistance training (RT) appear significantly greater than low load RT with BFR, BFR induces similar hypertrophy and lower joint forces/stress with low load RT compared to high load traditional RT without BFR (Bagley et al., 2015;Scott et al., 2016;Hughes et al., 2017;Centner et al., 2019;Rolnick and Schoenfeld, 2020a). Besides the potential implementation of BFRT in clinical musculoskeletal rehabilitation (e.g., knee osteoarthritis, and anterior cruciate ligament reconstruction) (Hughes et al., 2017), clinicians prescribing BFRT are often faced with the BFRT paradox: while participation in regular BFRT (e.g., aerobic training, resistance training, and passively without exercise) is acknowledged to offer significant benefits in muscle mass and strength, it can possibly result in adverse events (e.g., numbness, nausea, hypertension, headache, venous thrombus, deterioration of ischemic heart disease, fainting, tingling, excessive pain, central retinal vein occlusion, and rhabdomyolysis) if applied inappropriately (Nakajima et al., 2006;Ozawa et al., 2015;Noto et al., 2017;Yasuda et al., 2017;Patterson and Brandner, 2018;de Queiros et al., 2021). Such occurrences are very infrequent but have been previously documented. ...
... The third pilot study evaluated the effects of 8 weeks of BFRT on leg extension strength (30% of 1RM with cuff inflated between 15 and 20 mmHg greater than brachial systolic pressure) along with hemodynamic, vascular function, and blood markers in patients with stable coronary artery disease (>3 months after acute coronary syndrome, revascularization, and/or documented by coronary angiography) (Kambic et al., 2019). Similar to literature on healthy individuals and other clinical populations (Hughes et al., 2017), BFRT increased muscle strength [+16.37% (BFRT) vs. + 5.29% (control group)] with reductions in SBP (−7 mmHg) and a tendency of better endothelial function (p = 0.079) (evaluated by FMD). ...
Article
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Blood flow restriction training (BFRT) is a modality with growing interest in the last decade and has been recognized as a critical tool in rehabilitation medicine, athletic and clinical populations. Besides its potential for positive benefits, BFRT has the capability to induce adverse responses. BFRT may evoke increased blood pressure, abnormal cardiovascular responses and impact vascular health. Furthermore, some important concerns with the use of BFRT exists for individuals with established cardiovascular disease (e.g., hypertension, diabetes mellitus, and chronic kidney disease patients). In addition, considering the potential risks of thrombosis promoted by BFRT in medically compromised populations, BFRT use warrants caution for patients that already display impaired blood coagulability, loss of antithrombotic mechanisms in the vessel wall, and stasis caused by immobility (e.g., COVID-19 patients, diabetes mellitus, hypertension, chronic kidney disease, cardiovascular disease, orthopedic post-surgery, anabolic steroid and ergogenic substance users, rheumatoid arthritis, and pregnant/postpartum women). To avoid untoward outcomes and ensure that BFRT is properly used, efficacy endpoints such as a questionnaire for risk stratification involving a review of the patient’s medical history, signs, and symptoms indicative of underlying pathology is strongly advised. Here we present a model for BFRT pre-participation screening to theoretically reduce risk by excluding people with comorbidities or medically complex histories that could unnecessarily heighten intra- and/or post-exercise occurrence of adverse events. We propose this risk stratification tool as a framework to allow clinicians to use their knowledge, skills and expertise to assess and manage any risks related to the delivery of an appropriate BFRT exercise program. The questionnaires for risk stratification are adapted to guide clinicians for the referral, assessment, and suggestion of other modalities/approaches if/when necessary. Finally, the risk stratification might serve as a guideline for clinical protocols and future randomized controlled trial studies.
... Exercise training with blood flow restriction (BFR) is considered a potentially useful method for clinical musculoskeletal rehabilitation as a replacement for traditional heavy load strength training for populations who are unable to withstand high mechanical stressors (Hughes et al., 2017). BFR exercise involves applying external pressure around the muscle using a tourniquet-inflated cuff to the most proximal region of the upper or lower limbs (Patterson et al., 2019). ...
... This method can be used during resistance and aerobic exercise as well as applied pas-sively without exercise (Patterson et al., 2019). Longitudinal results indicate that low-load exercise training with BFR can produce greater muscular strength responses than low-load exercise without BFR with comparable gains in muscle mass compared to heavy load exercise (Hughes et al., 2017;Lixandrao et al., 2018). ...
... Those positive musculoskeletal benefits observed in both clinical and healthy populations highlight the need for nephrologists, physiotherapists, and physical education professionals to understand the possible use of this modality on treating functional impairments and the disablement process of patients with chronic kidney disease (CKD) (Centner et al., 2019;Hughes et al., 2017;Lixandrao et al., 2018;Roshanravan et al., 2017). CKD consists of kidney damage and progressive and irreversible loss of kidney function (glomerular, tubular, and endocrine) and for didactic and conceptual purposes, CKD is divided into six functional stages according to the patient's degree of renal function, with the last stage requiring some renal replacement therapy (KDIGO, 2021). ...
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Combining blood flow restriction (BFR) with exercise is considered a relevant, helpful method in load-compromised individuals and a viable replacement for traditional heavy-load strength training. BFR exercise may be particularly useful for those unable to withstand high mechanical stresses on joints resulting in skeletal muscle dysfunction, such as patients with chronic renal disease (CKD). Current literature suggests that BFR training displays similar positive health benefits to exercise training alone for CKD patients, including maintenance in muscle strength, glomerular filtration rate maintenance, uremic parameters, inflammatory profile, redox status, glucose homeostasis, blood pressure adjustments, and low adverse reports. In this review of 9 studies in CKD patients, we clarify the potential safety and health effects of exercise training with BFR compared to exercise training alone and recommend insights for future research and practical use. Furthermore, we introduce relevant gaps in this emerging field, providing substantial guidance, critical discussion, and valuable conclusions in this demographic of patients; However, based on the limited studies in this area, more research is necessary to determine the optimal BFR exercise programming.
... Exercise training with blood flow restriction (BFR), or Kaatsu training, is an increasingly common clinical intervention among physical therapists and other medical and/or exercise professionals 1) . BFR training uses an external cuff to partially occlude arterial blood flow and completely occlude venous return of an exercising limb, inducing tissue hypoxia and triggering a cascade of events including anaerobic metabolism, protein synthesis, and satellite cell proliferation 2,3) . As a result, low intensity resistance training with BFR (20-30% of 1-repetition max [1RM]) can be as effective at increasing muscle strength and mass as high intensity training without BFR (70-80% of 1RM) in people with musculoskeletal conditions [3][4][5] . ...
... BFR training uses an external cuff to partially occlude arterial blood flow and completely occlude venous return of an exercising limb, inducing tissue hypoxia and triggering a cascade of events including anaerobic metabolism, protein synthesis, and satellite cell proliferation 2,3) . As a result, low intensity resistance training with BFR (20-30% of 1-repetition max [1RM]) can be as effective at increasing muscle strength and mass as high intensity training without BFR (70-80% of 1RM) in people with musculoskeletal conditions [3][4][5] . In addition to resistance training, BFR has been shown to improve muscle performance and aerobic capacity during aerobic exercise 6,7) . ...
... While survey respondents in this study reported a variety of benefits associated with BFR training for their patients with neurologic conditions, these retrospectively reported clinical observations do not formally support the efficacy of BFR use in these conditions 27) . The most common benefit was improved muscle strength, which is consistent with the BFR literature in people with musculoskeletal conditions and older adults 3) . There is also early evidence to support improved or maintained strength following BFR training in people with CP 12) , MS 19) , PD 21) , SCI 23) , and inclusion body myositis 13) . ...
Article
[Purpose] There is little evidence for blood flow restriction (BFR), or Kaatsu, training in people with neurologic conditions. This study's purpose was to survey clinicians on BFR use in people with neurologic conditions. [Participants and Methods] One-hundred twelve physical therapists and other healthcare professionals who reported using BFR in the past 5 years completed an anonymous, online survey. [Results] Eighty-nine percent of respondents thought BFR was safe in people with neurologic conditions. Meanwhile, 38% reported BFR use in people with neurologic conditions. The most common intervention used with BFR was resistance training (n=33) and the most commonly reported benefit was improved strength (n=27). The most common side-effect causing treatment to stop was intolerance to pressure (n=6). No side-effects requiring medical attention were reported. In order to support future BFR use in neurologic populations, the most common response was the need for more research (n=63). [Conclusion] Despite the lack of evidence, clinical use of BFR in people with neurologic conditions may be somewhat common. Although this study had a relatively small sample size and collected data retrospectively, the results support the potential clinical feasibility and safety of BFR use in patients with neurologic conditions and suggest that more research is needed.
... 2,[21][22][23] The clinical interest in this phenomenon relates to the capacity to provide a sufficient exercise stimulus with reduced mechanical load that may be performed in the early stages following injury or in the early postoperative period after surgery. 1,11,24,25 Although the need for further research remains, the acute and chronic skeletal muscle responses to BFR have heavily characterized in numerous basic and applied investigations as well as summarized in a number of systematic reviews and meta-analyses with regard to musculature distal to the site of occlusion. 2,21,[26][27][28][29][30][31][32][33] To summarize, the skeletal muscle response to BFR-LIX has been hypothesized to be caused by a combination of intramuscular metabolic stress sensing, metabolite accumulation, mechanotransduction signaling (via muscle contractile activity and cell swelling caused by occlusion), hormonal responses to exercise, intracellular hypoxia, and inflammatory signaling mechanisms. ...
... However, recent systematic reviews and meta-analyses are progressively merging similar findings to provide clinicians with greater consistency in clinical application. 1,4,15,22,101,109 Currently unknown are how differentiation in these protocols affect proximal versus distal musculature to a greater degree. Table 2 includes selected activities prevalent in the literature and clinical practice targeted at vital proximal musculature that take precedence in upper-or lower-extremity rehabilitation. ...
Article
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The use of blood flow restriction (BFR) within rehabilitation is rapidly increasing as further research is performed elucidating purported benefits such as improved muscular strength and size, neuromuscular control, decreased pain, and increased bone mineral density. Interestingly, these benefits are not isolated to structures distal to the occlusive stimulus. Proximal gains are of high interest to rehabilitation professionals, especially those working with patients who are limited due to pain or postsurgical precautions. The review to follow will focus on current evidence and ongoing hypotheses regarding physiologic responses to BFR, current clinical applications, proximal responses to BFR training, potential practical applications for rehabilitation and injury prevention, and directions for future research. Interestingly, benefits have been found in musculature proximal to the occlusive stimulus, which may lend promise to a greater variety of patient populations and conditions. Furthermore, an increasing demand for BFR use in the sports world warrants further research for performance research and recovery. Level of Evidence Level V, expert opinion.
... Low-load resistance exercise performed with concurrent blood flow restriction (BFR) typically achieved by means of pneumatic cuff compression applied proximally around the exercising limb has repeatedly demonstrated significant improvements in skeletal muscle mass, strength, and functional performance in both healthy, elderly individuals, and clinical populations (10,(14)(15)(16)(17)(18)(19). BFR training is known to create a hypoxic myocellular environment in the working limb, which is suggested to give rise to elevated levels of metabolic stress that may lead to increased type II muscle fibre recruitment (20), myocellular swelling (21), and elevated intramuscular concentrations of metabolites (22) accompanied by increased synthesis of muscle protein. ...
... Consequently, the application of BFR-walking may represent a feasible and effective training modality for individuals with knee OA. Previous investigations have reported BFR exercise as safe when correctly and cautiously implemented (18,(25)(26)(27)(28)(29). However, only a single case study has investigated functional performance following BFR-walking in an individual with knee OA (30). ...
Article
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Objective: To investigate if blood flow restricted walking exercise is feasible in patients suffering from knee osteoarthritis, and secondly to examine changes in functional performance and self-reported function. Design: Feasibility study. Patients and methods: Fourteen elderly individuals diagnosed with knee osteoarthritis participated in 8-10 weeks of outdoor walking (4 km/h, 20 minutes/session, 4 times/week) with partial blood flow restriction applied to the affected leg. Adherence, drop-outs and adverse events were registered. Timed-Up&Go, 30-s sit-to-stand performance, 40-m fast-paced walk speed, stair-climbing and Knee Osteoarthritis Outcome Score were assessed pre- and post-training. Results: Nine participants completed the intervention, while five participants withdrew of which four experienced cuff discomfort or exacerbated knee pain. Baseline BMI (p=0.05) and knee pain (p=0.06) were higher while gait performance (p=0.04) was reduced in non-completing participants. Considering completed case data, training-adherence rate was 93%, while mean knee pain in the affected leg was 0.7 on a numerical rating scale from 0-10. Functional performance improved, while self-reported function remained unchanged. Conclusion: Blood flow restricted walking exercise appeared feasible in patients with knee osteoarthritis although possibly affected by participants' baseline characteristics. Participants who completed the intervention protocol demonstrated improvements in functional performance, without any changes in self-reported function.
... Strength exercise performed with low external loading (LL, ≤50% of one-repetition maximum (1RM)) and partial (< full arterial occlusion) or full (full arterial occlusion) blood flow restriction (BFR) has been shown to be an effective training method promoting gains in neuromuscular function (e.g., maximal muscle strength) and skeletal muscle growth [1][2][3][4]. Similar gains in these parameters have been reported between LL-BFR training and conventional high-load resistance training (≥65% 1RM) [1,2], however, these findings are not universal [3]. ...
... Strength exercise performed with low external loading (LL, ≤50% of one-repetition maximum (1RM)) and partial (< full arterial occlusion) or full (full arterial occlusion) blood flow restriction (BFR) has been shown to be an effective training method promoting gains in neuromuscular function (e.g., maximal muscle strength) and skeletal muscle growth [1][2][3][4]. Similar gains in these parameters have been reported between LL-BFR training and conventional high-load resistance training (≥65% 1RM) [1,2], however, these findings are not universal [3]. ...
Article
This paper aimed to examine the acute effect of low-load (LL) exercise with blood-flow restriction (LL-BFR) on microvascular oxygenation and muscle excitability of the vastus medialis (VM) and vastus lateralis (VL) muscles during a single bout of unilateral knee extension exercise performed to task failure. Seventeen healthy recreationally resistance-trained males were enrolled in a within-group randomized cross-over study design. Participants performed one set of unilateral knee extensions at 20% of one-repetition maximum (1RM) to task failure, using a LL-BFR or LL free-flow (LL-FF) protocol in a randomized order on separate days. Changes in oxygenation and muscle excitability in VL and VM were assessed using near-infrared spectroscopy (NIRS) and surface electromyography (sEMG), respectively. Pain measures were collected using the visual analog scale (VAS) before and following set completion. Within- and between- protocol comparisons were performed at multiple time points of set completion for each muscle. During LL-BFR, participants performed 43% fewer repetitions and reported feeling more pain compared to LL-FF (p<0.05). Normalized to time to task failure, LL-BFR and LL-FF generally demonstrated similar progression in microvascular oxygenation and muscle excitability during exercise to task failure. The present results demonstrate that LL-BFR accelerates time to task failure, compared with LL-FF, resulting in a lower dose of mechanical work to elicit similar levels of oxygenation, blood-pooling, and muscle excitability. LL-BFR may be preferable to LL-FF in clinical settings where high workloads are contraindicated, although increased pain experienced during BFR may limit its application.
... Therefore, the findings of the present review are consistent with current literature comparing LL-BFR training to LLR and HLR training in healthy and postoperative patients. [40][41][42][43][44][45][46] In regard to quadriceps mass, two studies demonstrated that LL-BFR training was more beneficial on quadriceps cross-sectional area (CSA) compared to non-BFR training. 37,38 In contrast, Iversen et al. observed no difference in quadriceps CSA between LL-BFR and non-BFR training. ...
... 35 Thus, the results of the present review are consistent with literature showing that LL-BFR training may be beneficial on quadriceps mass compared to LLR training and equally effective when compared to HLR training in healthy and postoperative patients. [40][41][42][43][44][45][46] The application of LL-BFR has generally been indicated for the elderly or injured/postoperative patients who cannot tolerate high external loads. 43,[47][48][49][50] This review adds evidence on the application of LL-BFR as three studies assessing pain observed improved pain relief with LL-BFR compared to non-BFR training in patients following ACL surgery. ...
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Background: Quadriceps strength and mass deficits are common after anterior cruciate ligament (ACL) reconstruction. Postoperatively, heavy load resistance training can have detrimental effects on knee joint pain and ACL graft laxity. Therefore, low-load blood flow restriction (LL-BFR) training has been suggested as an alternative to traditional strength rehabilitation. Purpose: The present systematic review aimed to investigate the effect of LL-BFR training on quadriceps strength, quadriceps mass, knee joint pain, and ACL graft laxity after ACL reconstruction compared to non-BFR training. Study design: Systematic review. Methods: A systematic literature search of PubMed, EMBASE.com, Cochrane Library/Wiley, CINAHL/Ebsco and Web of Science/Clarivate Analytics was performed on 19 February 2021. Studies were included if they compared LL-BFR and non-BFR training after ACL reconstruction with pre- and post-intervention quadriceps strength, quadriceps mass, knee joint pain or ACL graft laxity measurement. Systematic reviews, editorials, case reports and studies not published in a scientific peer reviewed journal were excluded. The risk of bias of randomized studies was assessed with the use of the Cochrane Risk of Bias Tool. Results: A total of six randomized controlled trials were included. Random sequence generation and allocation concealment was defined as high risk in two of the six studies. In all studies blinding of participants and personnel was unclear or could not be performed. The included studies used different LL-BFR and non-BFR protocols with heterogeneous outcome measurements. Therefore, a qualitative analysis was performed. Two of the six studies assessed quadriceps strength and demonstrated significant greater quadriceps strength after LL-BFR compared to non-BFR training. Quadriceps mass was evaluated in four studies. Two studies observed significant greater quadriceps mass after LL-BFR compared to non-BFR training, while two studies observed no significant difference in quadriceps mass. Knee joint pain was assessed in three studies with significantly less knee joint pain after LL-BFR compared to non-BFR training. Two studies evaluated ACL graft laxity and observed no significant difference in ACL graft laxity between LL-BFR and non-BFR training. Conclusion: The results of this systematic review indicate that LL-BFR training after ACL reconstruction may be beneficial on quadriceps strength, quadriceps mass, and knee joint pain compared to non-BFR training with non-detrimental effects on ACL graft laxity. However, more randomized controlled trials with standardized intervention protocols and outcome measurements are needed to add evidence on the clinical value of LL-BFR training. Level of evidence: 2a.
... BFRT consist of exercising using a surgical grade pneumatic cuff or tourniquet that partially restricts arterial inflow, and fully restricts venous outflow from the working musculature during exercise. 15,16 The clinical value of BFRT that has been suggested in the literature is that it allows increased muscle adaptation and hypertrophy with LL-RT, 17 making BFRT a potentially advantageous tool to implement in the early post-operative population. The utilization of BFRT in conjunction with current rehabilitation standards of care has shown potential with respect to muscle adaptations and performance. ...
... A meta-analysis comparing BFRT on musculoskeletal rehabilitation versus traditional LL-RT, reported low load BFRT training to be more effective in helping patients regain strength than traditional LL-RT. 17 A common point of discussion regarding BFRT is the potential safety risk, specifically in the post-surgical population. Possible concerns include the effects of BFRT on the cardiovascular system such as blood pressure responses, potential thrombolytic events and damage to the vascular system. ...
Article
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Background: Blood flow restriction training (BFRT) has gained popularity in rehabilitation due to its benefits in reducing muscle atrophy and mitigating strength deficits following anterior cruciate ligament reconstruction (ACLR). While the effectiveness and safety of BFRT has been well studied in healthy adult subjects, there is limited information about the use of BFRT in the adolescent population, specifically related to patient tolerance and reported side effects post ACLR. Purpose: To investigate and record reported side effects and patient tolerance to BFRT during ACLR rehabilitation in adolescents. Study design: Prospective Cohort Study. Methods: Patients between 12 and 18 years of age who underwent ACLR at Connecticut Children's were included. Patients utilized an automatic personalized tourniquet system and followed a standardized BFRT exercise protocol over 12 weeks starting 8.72 ± 3.32 days post-op. Upon completion of exercise while using BFRT, patients reported side effects and any adverse events were logged. Descriptive statistics were used to describe the reported side effects and adverse events associated with BFRT and calculate the frequencies of those events over a 12-week period. Results: Five hundred and thirty-five total BFRT sessions were completed between 29 patients (15.39 ± 1.61 years of age). There were zero reports of subcutaneous hemorrhage (SubQ hemorrhage) and deep vein thrombosis (DVT). Reported minor side effects to BFRT included itchiness of the occluded limb (7.85%), lower extremity paresthesia (2.81%), and dizziness (0.75%). A total of 10.47% of BFR treatment sessions were unable to be completed due to tolerance, and 3.5% of sessions required a reduction in limb occlusion pressure (LOP). Conclusion: These preliminary data suggest that BFRT is safe with only minor side effects noted in the adolescent population after ACLR. Further investigations are warranted to continue to evaluate patient tolerance and safety with BFRT, because while these preliminary results suggest a positive safety profile and good tolerance in the adolescent population after ACLR, they represent the experiences of only a small sample. Level of evidence: Level 3.
... RE with blood flow restriction (BFR) is a unique method that uses low-load (Patterson et al., 2019;Scott et al., 2015). The BFR-RE results in muscle hypertrophy and strength gain more than non-BFR (NBFR)-RE in various populations (Lixandrão et al., 2018), including older individuals and patients with chronic diseases (Centner et al., 2019;Hughes et al., 2017). Moreover, muscle hypertrophy and strength gain induced by low-load BFR-RE is comparable to those induced by high-load NBFR-RE (Centner et al., 2019;Lixandrão et al., 2018). ...
... In particular, athletes and trained individuals may exhibit different BFR-RE-induced physiological responses compared to untrained individuals (Takada et al., 2012). Furthermore, applications of BFR exercises, including RE, to increase skeletal muscle mass and strength may be more useful in older individuals and patients with chronic diseases than in young individuals; this is because the BFR-RE is being recognized as a beneficial strategy in these populations (Centner et al., 2019;Hughes et al., 2017), including older patients with congestive heart failure (Groennebaek et al., 2019). To extend the findings of this pilot study involving young males, further studies are needed to examine the effects of BFR on perceptual responses to low-load RE in various populations and identify an effective strategy that minimize the low-load BFR-RE-induced negative effects on perceptual response, while also taking into consideration the uniqueness of each population. ...
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Resistance exercise (RE) with blood flow restriction (BFR) is recognized as a beneficial strategy in increasing skeletal muscle mass and strength. However, the effects of BFR on changes in perceptual parameters, particularly those related to exercise adherence, induced by RE are not completely understood. In this study, we examined the exercise adherence-related perceptual responses to low-load BFR-RE. Sixteen young males performed both BFR and non-BFR (NBFR) sessions in a crossover design. The bilateral knee extensor low-load RE was performed with a standard BFR-RE protocol, consisting of four sets (total 75 repetitions), using 20% of one-repetition maximum. BFR-RE was performed with 200 mmHg pressure cuffs placed around the proximal region of the thighs. NBFR-RE was performed without pressure cuffs. The ratings of perceived exertion and leg discomfort measured using the Borg's Scales were higher for BFR-RE session than for NBFR-RE session (both p < 0.001 for interaction effect). The Feeling Scale-measured affect and Task Motivation Scale-measured task motivation were lower for BFR-RE session than for NBFR-RE session (both p < 0.05 for interaction effect); by contrast, the Numerical Rating Scale-measured perceived pain was higher for BFR-RE session than for NBFR-RE session (p < 0.001 for interaction effect). The Physical Activity Enjoyment Scale-measured enjoyment immediately after RE was lower with BFR than with NBFR (p < 0.001). These findings suggest that BFR exacerbates the exercise adherence-related perceptual responses to low-load RE in young males. Therefore, further studies are needed to develop effective strategies that minimize the BFR-RE-induced negative effects on perceptual responses.
... In the field of physiotherapy, BFR is becoming increasingly important since it has sparked interest from its application in training, in which it can be extrapolated to therapeutic exercise [10]. Among the methodologies used by this technique, there is heterogeneity in terms of the results as a consequence of the type of occlusion used, pressure of the arterial occlusion or pressure of the limb occlusion, the type of material used, the width of the cuff, the quantity of applied pressure (pressures between 40% and 80% are generally exerted) and the training method (aerobic or strength) [11,12]. ...
... Within the muscle physiological changes, short-term changes were observed for the fatigue variable in the BFR group of 21.43% with the Modified Fatigue Impact Scale (MFIS) and in the control group of 7.69% with the Fatigue Severity Scale (FSS) [39]. These results confirm that the application of BFR while walking produces the same benefits as walking, although the difference-in favor of the BFR group-may be due to the fact that a lower pressure than usual was applied in the control group [10]. On the other hand, in the effort variable, no differences were found between the BFR groups and high-load exercise for both legs, showing changes in the Rating Perceived of Exertion (RPE) of 13.9% for the BFR group in the injured limb and 14% and 8% for the control group in the injured leg [51]. ...
Article
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The main objective of this systematic review of the current literature is to analyze the changes that blood flow restriction (BFR) causes in subjects with neuro-musculoskeletal and/or systemic pathologies focusing on the following variables: strength, physiological changes, structural changes and cardiocirculatory variables. The search was carried out in seven databases, including randomized clinical trials in which therapeutic exercise was combined with the blood flow restriction tool in populations with musculoskeletal pathologies. Outcome variables are strength, structural changes, physiological changes and cardiocirculatory variables. Twenty studies were included in the present study. Although there is a lot of heterogeneity between the interventions and evaluation instruments, we observed how the restriction of blood flow presents significant differences in the vast majority of the variables analyzed. In addition, we observed how BFR can become a supplement that provides benefits when performed with low intensity, similar to those obtained through high-intensity muscular efforts. The application of the BFR technique can provide benefits in the short and medium term to increase strength, muscle thickness and cardiovascular endurance, even improving the physiological level of the cardiovascular system. In addition, BFR combined with low-load exercises also achieves benefits comparable to high-intensity exercises without the application of BFR, benefiting patients who are unable to lift high loads.
... Moreover, sIBM patients appeared to tolerate 12-weeks low-load BFR training, evidenced by unchanged levels of T-cells and macrophages in the trained muscles [18] . In healthy adults, BFR training has consistently been shown to stimulate skeletal muscle growth and upregulate muscle stem cell (satellite cells, SC) content [19][20][21] . SCs play an essential role in skeletal muscle regeneration by (i) providing fusion-capable myoblasts to support myofibre regeneration and (ii) maintain/improve transcriptional capacity during exerciseinduced myofibre hypertrophy through myonuclei addition [22][23][24] . ...
... To our best knowledge no prior study has examined the plasticity in skeletal muscle SC content of elderly undergoing BFR training. However, increased SCs content with BFR training has been observed in other populations [19][20][21] . Somewhat unexpected, therefore, resident SC content was found to remain unchanged in the present sIBM patients following BFR resistance training. ...
Article
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Sporadic inclusion body myositis (sIBM) is characterised by skeletal muscle inflammation, progressive muscle loss and weakness, which is largely refractory to immunosuppressive treatment. Low-load blood-flow restricted (BFR) training has been shown to evoke gains in myofibre cross sectional area (mCSA) in healthy adults. This could partially be due to the activation and integration of muscle satellite cells (SC) resulting in myonuclei addition. Consequently, this study investigated the effect of 12-weeks lower limb low-load BFR resistance training in sIBM patients on SC and myonuclei content, myofibre size and capillarization. Muscle biopsies from sIBM patients randomised to 12-weeks of low-load BFR resistance training (BFRE) (n=11) or non-exercising controls (CON) (n=9) were analysed for SC and myonuclei content, myofibre size and capillarization using three-color immunofluorescence microscopy and computerised quantification procedures. No between-group differences (time-by-group interactions) or within-groups changes were observed for resident SCs (Pax7⁺/Six1⁺), proliferating SCs (Pax7⁺/ Ki67⁺), myonuclei (Six1⁺), type 1 mCSA or capillary number (CD31⁺). However, a time-by-group interaction for type 2 mCSA was observed (p=0.04). Satellite cell content, myonuclei number, mCSA and capillary density remained unaffected following 12-weeks low-load BFR resistance training, indicating limited myogenic capacity and satellite cell plasticity in long-term sIBM patients.
... The BFR has shown promising results in musculoskeletal rehabilitation. It consists of a momentary and controlled mechanical compression of the proximal segment of the limb [25]. The most accepted mechanisms that can explain the development of muscle hypertrophy in BFR is the accumulation of metabolites around the trained muscle as an adaptive response to local hypoxemia [26,27]. ...
... Thus, there is still lack of information about the most efficient and safety levels of pressure applied by the cuff to restrict blood flow and on the combination or not of the BFR with other therapeutic modalities [36]. Positive results for muscle strength improvement have been found using the BFR with 40 to 90% of the total arterial limb occlusion pressure (LOP) [37], associated with resistance exercises using low loads that vary between 10 and 30% of 1 RM [25]. Yet, no study has assessed whether BFR at rest could also promote similar gains in muscle strength for the knee OA treatment, which theoretically would increase adherence to knee OA treatment by patients, for minimizing the physical discomfort commonly presented in high and moderateintensity exercises [31]. ...
Article
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Background The effectiveness of blood flow restriction training (BFR) in elderly with knee osteoarthritis (OA) is comparable to performing high-intensity protocols (70 to 80% of 1 RM [repetition maximum]) that are known to be effective for improving the muscle strength of knee extensors, with the advantage of generating less particular rating of perceived exertion and pain immediately after training. However, despite being a promising alternative, little is known about the best way to apply the BFR, such as level of pressure and combination or not with other therapeutic modalities. The purpose of this study is to evaluate whether different levels of blood flow restriction with low load (BFR + LL) and no load (BFR + rest) are non-inferior to high-intensity resistance exercise (HIRE+BFRplacebo) for pain reduction in patients with knee OA. Methods/design This clinical trial is a non-inferiority, five-arm, randomized, active-controlled, single trial which will be carried out in 165 patients of both sexes with knee OA, aged 50 years and older. Participants will be randomly allocated into 5 exercise groups (40% of BFR + LL; 80% of BFR + LL; 40% of BFR + rest; 80% BFR + rest, and HIRE+BFR placebo). A mixed linear model will be used to examine the effect of group-by-time interaction on pain intensity on the WOMAC subscale (primary outcome) and on disease severity, physical functional data, balance data, quality of life, global perceived effect scale, and muscle strength (secondary outcomes). Participants will be analyzed for intention-to-treat, and the statistical assessor blinded to the groups. The collection of outcomes 72 h after completion of the 16 weeks of interventions will be the primary measurement point. Follow-up secondary timepoints will be collected at 20, 28, 40, 52, and 64 weeks after the end of interventions, except for pain during the training, which will be measured immediately at the end of each session. Only the comparison of the primary outcome between the HIRE group with each BFR group will be analyzed in the non-inferiority framework, the other comparisons between the BFR groups for the primary outcome, and all secondary outcomes will be interpreted in the superiority framework. Discussion The results of this clinical trial can point out more clearly to ways to optimize the BFR training with the minimum of pain immediately after training, which will allow the offer of an effective and more adherent strengthening training to patients with knee OA. Trial registration Registro Brasileiro de Ensaios Clínicos , RBR-93rx9q . Registered on 23 July 2020. Version 1.0.
... A new blood flow restriction (BFR) approach, which partially restricts arterial inflow while totally limiting venous outflow in the muscles during exercise, offers an intriguing alternative [236,237]. During low-intensity training, this approach allows for a significant gain in skeletal muscle strength. ...
... [236]. However, some experts are concerned about the method's potential adverse side effects and propose that training only occurs under the supervision of qualified staff [236,237]. ...
Article
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Obesity and ageing place a tremendous strain on the global healthcare system. Age-related sarcopenia is characterized by decreased muscular strength, decreased muscle quantity, quality, and decreased functional performance. Sarcopenic obesity (SO) is a condition that combines sarcopenia and obesity and has a substantial influence on the older adults’ health. Because of the complicated pathophysiology, there are disagreements and challenges in identifying and diagnosing SO. Recently, it has become clear that dysbiosis may play a role in the onset and progression of sarcopenia and SO. Skeletal muscle secretes myokines during contraction, which play an important role in controlling muscle growth, function, and metabolic balance. Myokine dysfunction can cause and aggravate obesity, sarcopenia, and SO. The only ways to prevent and slow the progression of sarcopenia, particularly sarcopenic obesity, are physical activity and correct nutritional support. While exercise cannot completely prevent sarcopenia and age-related loss in muscular function, it can certainly delay development and slow down the rate of sarcopenia. The purpose of this review was to discuss potential pathways to muscle deterioration in obese individuals. We also want to present the current understanding of the role of various factors, including microbiota and myokines, in the process of sarcopenia and SO.
... Thus, it is increasingly important to identify evidence-based interventions that can mitigate the functional decline occurring progressively with advancing age. In recent years, strength training has been used in the elderly, and its benefits have gained increasing attention in the scientific community [5][6][7]. ...
... In light of this, more aggressive protocols of resistance training involving the addition of the so-called blood flow restricted (BFR) technique have also been trialed with success in the elderly [5][6][7]. Several studies [7][8][9] have demonstrated significant improvements in functional capacity in this deteriorated population after a period of strength training with BFR and low loads, compared to a control group. In this same context, another method of vascular occlusion, ischemic preconditioning (IPC), has been reported to be ergogenic for musculoskeletal recovery [10,11] and sports performance [12]. ...
Article
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Background: Aging decreases some capacities in older adults, sarcopenia being one of the common processes that occur and that interfered with strength capacity. The present study aimed to verify the acute effect of IPC on isometric handgrip strength and functional capacity in active elderly women. Methods: In a single-blind, placebo-controlled design, 16 active elderly women (68.1 ± 7.6 years) were randomly performed on three separate occasions a series of tests: (1) alone (control, CON); (2) after IPC (3 cycles of 5-min compression/5-min reperfusion at 15 mmHg above systolic blood pressure, IPC); and (3) after placebo compressions (SHAM). Testing included a handgrip isometric strength test (HIST) and three functional tests (FT): 30 s sit and stand up from a chair (30STS), get up and go time (TUG), and 6 min walk distance test (6MWT). Results: HIST significantly increased in IPC (29.3 ± 6.9 kgf) compared to CON (27.3 ± 7.1 kgf; 7.1% difference; p = 0.01), but not in SHAM (27.7 ± 7.9; 5.5%; p = 0.16). The 30STS increased in IPC (20.1 ± 4.1 repetitions) compared to SHAM (18.5 ± 3.5 repetitions; 8.7%; p = 0.01) and CON (18.5 ± 3.9 repetitions; 8.6%; p = 0.01). TUG was significantly lower in IPC (5.70 ± 1.35 s) compared to SHAM (6.14 ± 1.37 s; -7.2%; p = 0.01), but not CON (5.91 ± 1.45 s; -3.7%; p = 0.24). The 6MWT significantly increased in IPC (611.5 ± 93.8 m) compared to CON (546.1 ± 80.5 m; 12%; p = 0.02), but not in SHAM (598.7 ± 67.6 m; 2.1%; p = 0.85). Conclusions: These data suggest that IPC can promote acute improvements in handgrip strength and functional capacity in active elderly women.
... BFRT has executable functionality in older individuals with minimal risk of damage (23,30,64,99), and thus, it is suitable for older individuals and those with sarcopenia along with underlying diseases who have marked physical limitations. Patients with sarcopenia who often underwent BFR combined with low-load resistance training did not experience sustained declines in muscle function, exaggerated levels of muscle soreness or increased muscle injury (20,100,101), which is beneficial for clinical rehabilitation and elderly populations unsuitable for high loads. Because of its relative ease of implementation and its low load, BFRT enables older individuals to perform more habitual physical activity, which is essential in treating sarcopenia ...
... Muscle capacity Increased muscle strength corresponds with muscle hypertrophy (24); Gains in physical function led by enhanced muscular power (94); Improvements in muscular endurance led by repetitions (94); Safety method with potential beneficial effects in protecting and augmenting muscle mass and nAChR clustering at the neuromuscular junction (44); More effectiveness in increasing muscle strength compared to low intensity training alone (92) No nervous system adaptations that result in enhanced muscle strength (24); Lack of training in core, back, and neck muscles (105); Lack of morphological and/or mechanical tendon/bone adaptations (49,99); Potential myocellular muscle damage and even rhabdomyolysis led by unaccustomed or excessive BFR exercise (107,108); Less effectiveness compared to heavy-load training (no BFR) (92) Muscle innervation Beneficial effect on vascular function of muscle such as arterial compliance and endothelial function (86); Increase in HR and blood pressure (23); Less harmful for the healing of supporting tissues (92) Concerns of ischemic reperfusion injury (111); Induction of a sympathoexcitatory pressor reflex (104,110) Training load Usage as an effective alternative to low-load training and a surrogate for heavy-load training (100); Potential application as a clinical rehabilitation tool in the process of return to heavy-load exercise (20,100); Safety in patients early after open cardiac surgery led by well-monitored and stepwise-increased volume (98) Higher perceptual ratings of perceived exertion and pain during the rest intervals of sets can limit the application (101,105,106) Hemodynamics functions Increase in fibrinolytic activity to reduce the risk for blood coagulation (30); No increase in fibrinogen/fibrin degradation products and high-sensitive C-reactive protein to indicate affects in hemostatic and inflammatory responses (109) Concerns of disturbed hemodynamics (111); Complications evoked by the exercise pressor reflex (98) and significantly improves muscle strength, muscle mass and physical performance. BFRT can increase fibrinolytic activity, thus reducing the risk for blood coagulation (30,43). ...
Article
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Sarcopenia is a geriatric syndrome that is characterized by a progressive and generalized skeletal muscle disorder and can be associated with many comorbidities, including obesity, diabetes, and fracture. Its definitions, given by the AWGS and EWGSOP, are widely used. Sarcopenia is measured by muscle strength, muscle quantity or mass and physical performance. Currently, the importance and urgency of sarcopenia have grown. The application of blood flow restriction (BFR) training has received increased attention in managing sarcopenia. BFR is accomplished using a pneumatic cuff on the proximal aspect of the exercising limb. Two main methods of exercise, aerobic exercise and resistance exercise, have been applied with BFR in treating sarcopenia. Both methods can increase muscle mass and muscle strength to a certain extent. Intricate mechanisms are involved during BFRT. Currently, the presented mechanisms mainly include responses in the blood vessels and related hormones, such as growth factors, tissue hypoxia-related factors and recruitment of muscle fiber as well as muscle satellite cells. These mechanisms contribute to the positive balance of skeletal muscle synthesis, which in turn mitigates sarcopenia. As a more suited and more effective way of treating sarcopenia and its comorbidities, BFRT can serve as an alternative to traditional exercise for people who have marked physical limitations or even show superior outcomes under low loads. However, the possibility of causing stress or muscle damage must be considered. Cuff size, pressure, training load and other variables can affect the outcome of sarcopenia, which must also be considered. Thoroughly studying these factors can help to better determine an ideal BFRT scheme and better manage sarcopenia and its associated comorbidities. As a well-tolerated and novel form of exercise, BFRT offers more potential in treating sarcopenia and involves deeper insights into the function and regulation of skeletal muscle.
... Low-load exercises with concurrent restriction of the blood flow by means of a pneumatic cuff placed on the proximal part of the exercising extremity (LL-BFR) has consistently demonstrated promotion of skeletal muscle hypertrophy and increase strength in both patients and healthy individuals (Hughes et al., 2017;Lambert et al., 2018). Additionally, LL-BFR has been observed to increase muscle strength to the same extent as heavy load resistance strength training (Grønfeldt et al., 2020). ...
... In general, LL-BFR seems to be a well-tolerated and a safe exercise modality in both healthy and clinical populations, when safety precautions concerning cuff application, cuff pressure, and time with blood flow restriction are taken (Hughes et al., 2017;Patterson et al., 2019). ...
Article
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Introduction To date, there exists no gold standard conservative treatment for lateral hip pain due to tendinopathy of the gluteus medius and/or minimus tendon (GT), a condition often complicated by pain and disability. Higher loads during everyday activities and exercise seems to be contraindicated with GT. The purpose of this study was to evaluate the feasibility of exercise with low-loads concurrent partial blood flow restriction (LL-BFR) and patient education for patients present GT. Methods Recruitment took place at three hospitals in the Central Denmark Region. The intervention consisted of daily sessions for 8 weeks with one weekly supervised session. From week three patients exercised with applied partial blood flow restriction by means of a pneumatic cuff around the proximal thigh of the affected leg. Throughout the intervention patients received patient education on their hip condition. Sociodemographic and clinical variables were collected at baseline. The feasibility of LL-BFR was conducted by adherence to the exercise protocol and drop-out rate. Patient reported outcome measures (The Victorian Institute of Sport Assessment-Gluteal Questionnaire, EuroQol - 5 Dimensions-Visual Analogue Scale, Oxford Hip Score, Copenhagen Hip and Groin Outcome Score), maximal voluntary isometric hip abduction-, hip extension, and knee extension strength (Nm/kg) measured using a handheld dynamometer, and functional capacity tests (30 second chair-stand test and a stair-climb test) was conducted as secondary outcomes. Results Sixteen women with a median (IQR) age of 51 (46–60) years were included. Median (IQR) Body Mass Index was 26.69 (23.59–30.46) kg/m2. Adherence to the total number of training sessions and the LL-BFR was 96.4 and 94.4%, respectively. Two patients dropped out due to (i) illness before initiation of LL-BFR and (ii) pain in the affected leg related to the LL-BFR-exercise. At follow-up both pain levels and patient-reported outcome measures improved. Isometric hip abduction-, hip extension-, and knee extension strength on both legs and functional performance increased. Conclusion: LL-BFR-exercise seems feasible for treatment of GT. At follow-up, a high adherence and low drop-out rate were observed. Further, patients reported clinically relevant reductions in pain, and showed significant increases in isometric hip and knee strength.
... Returning astronauts are load compromised and perform initial reconditioning exercises at a low intensity to minimize the risk of injury 96 . BFR exercise is an effective rehabilitation tool for muscular, aerobic and functional adaptations in load compromised populations with minimized risk of injury [69][70][71] . It could be used to maximize adaptations to low intensity exercise, minimize risk of injury and treat transit-induced injuries during postflight reconditioning of astronauts on Earth and another planet (Fig 3). ...
Article
INTRODUCTION: During spaceflight missions, astronauts work in an extreme environment with several hazards to physical health and performance. Exposure to microgravity results in remarkable deconditioning of several physiological systems, leading to impaired physical condition and human performance, posing a major risk to overall mission success and crew safety. Physical exercise is the cornerstone of strategies to mitigate physical deconditioning during spaceflight. Decades of research have enabled development of more optimal exercise strategies and equipment onboard the International Space Station. However, the effects of microgravity cannot be completely ameliorated with current exercise countermeasures. Moreover, future spaceflight missions deeper into space require a new generation of spacecraft, which will place yet more constraints on the use of exercise by limiting the amount, size, and weight of exercise equipment and the time available for exercise. Space agencies are exploring ways to optimize exercise countermeasures for spaceflight, specifically exercise strategies that are more efficient, require less equipment, and are less time-consuming. Blood flow restriction exercise is a low intensity exercise strategy that requires minimal equipment and can elicit positive training benefits across multiple physiological systems. This method of exercise training has potential as a strategy to optimize exercise countermeasures during spaceflight and reconditioning in terrestrial and partial gravity environments. The possible applications of blood flow restriction exercise during spaceflight are discussed herein.Hughes L, Hackney KJ, Patterson SD. Optimization of exercise countermeasures to spaceflight using blood flow restriction. Aerosp Med Hum Perform. 2021; 93(1):32-45.
... (53)(54)(55) Blood flow restriction (BFR) therapy is safe to initiate within the first two weeks after surgery, assuming no contraindications are present and may help mitigate muscular atrophy and maximize the recovery of strength during this most restrictive phase of rehabilitation. (56)(57)(58) Quadriceps exercises begin with isometrics, first in extension, then in fixed angles of knee flexion (KF) as swelling resolves and ROM improves. Resisted quadriceps strengthening through an arc of motion is gradually incorporated over time to respectfully introduce anterior tibial shear forces to the healing ligament graft(s). ...
Article
The medial collateral (MCL) and fibular collateral (FCL) ligaments are the primary frontal plane stabilizers in the knee joint. Extreme varus, valgus, or rotational moments about the knee may cause the failure of these ligaments and contribute to persistent knee instability and functional deficits that may not respond to rehabilitation alone. Surgical intervention may be warranted when a complete disruption occurs to address resultant instability. Due to lower incidences of surgery to address MCL and FCL injuries, by comparison to anterior cruciate ligament reconstruction (ACLR), fewer high-quality studies exist addressing postoperative rehabilitation guidelines for the collateral ligaments. Additionally, little is known on performance-based outcomes and return to sport within this population, especially within the postoperative population. Standardized postoperative protocols for this population currently do not exist in the literature. Therefore, basic science on collateral ligament anatomy and biomechanics provides the foundation for postoperative rehabilitation, including precautions and the continuum of care to return a patient to sport. The objective of this text is to define the rationale for postoperative precautions, provide a template for phased rehabilitation strategies, and describe physical performance testing protocols to guide decisions on care progression and return to activity/sport following surgery to address medial and lateral knee instability.
... By far the most common form of BFR is with resistance exercise (BRF-RE), with multiple systematic reviews and meta-analyses demonstrating its benefits. [31][32][33][34] From these studies it is clear that low-load BFR-RE is superior in multiple respects, including building muscle strength and size, to that of isolated low load resistance training and comparable to that of high load resistance training alone. However, although lowload BFR-RE may not necessarily be superior to that of high-load resistance training in terms of muscle strength, the ability to train at a greater frequency with less mechanical stress on the joints allows for broad application, in postoperative, injured, and cardiac rehabilitation patients, in season athletes and elderly individuals. ...
Article
Full-text available
Blood flow restriction (BFR) is an expanding rehabilitation modality that uses a tourniquet to reduce arterial inflow and occlude venous outflow in the setting of resistance training or exercise. Initially, this technique was seen as a way to stimulate muscular development, but improved understanding of its physiologic benefits and mechanism of action has allowed for innovative clinical applications. BFR represents a way to decrease stress placed on the joints without compromising improvements in strength, whereas for postoperative, injured, or load-compromised individuals BFR represents a way to accelerate recovery and prevent atrophy. There is also growing evidence to suggest that it augments cardiovascular fitness and attenuates pain. The purpose of this review is to highlight the physiology and evidence behind the various applications of BFR, with a focus on postoperative rehabilitation. While much remains to be learned, it is clear that blood flow restriction therapy stimulates muscle hypertrophy via a synergistic response to metabolic stress and mechanical tension, with supplemental benefits on cardiovascular fitness and pain. New forms of BFR and expanding applications in postoperative patients and athletes hold promise for expedited recovery. Continued adherence to rehabilitation guidelines and exploration of BFRs physiology and various applications will help optimize its effect and prescription. Level of Evidence V, expert opinion.
... [44][45][46] Blood flow restriction is a valuable modality used to mitigate muscle atrophy and strength loss and is shown to be safe and effective in appropriate populations. 48 By the end of this phase, patients should exhibit full knee extension and 110 to 120 of knee flexion, be able to perform consecutive repetitions of straight leg raising with no extensor lag, and demonstrate good tolerance for progressive intensity with other beginning strengthening exercises. This indicates readiness for weight-bearing progression and gait training. ...
Article
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Multiligament knee injuries (MLKIs) are debilitating injuries that increasingly occur in young athletes. Return to sport (RTS) has historically been considered unlikely due to the severity of these injuries. Reporting in the literature regarding objective outcomes following MLKI, including RTS, is lacking, as are clear protocols for both rehabilitation progressions and RTS testing. RTS following MLKI is a complex process that requires an extended recovery duration compared to other surgery types. Progressions through postoperative rehabilitation and RTS should be thoughtful, gradual, and criterion based. After effective anatomic reconstruction to restore joint stability, objective measures of recovery including range of motion, strength, movement quality, power, and overall conditioning guide decision-making throughout the recovery process. It is important to frame the recovery process of the athlete in the context of the severity of their injury, as it is typically slower and less linear. Improved reporting on objective outcomes will enhance our understanding of recovery expectations within this population by highlighting persistent deficits that may interfere with a full recovery, including RTS.
... BFRT involves the application of straps or pneumatic cuffs around an upper or lower limb extremity, with cuff pressure aiming to partially restrict arterial blood flow, while also occluding venous outflow while the cuff pressure remains intact (Lorenz et al., 2021;. BFRT has been shown to be an effective resistance training method for enhancing muscle strength and hypertrophy in healthy populations and in the rehabilitation of musculoskeletal pathologies and following orthopaedic surgery (Barber-Westin et al., 2019;Hughes et al., 2017;Nitzsche et al., 2021;Lowery et al., 2014). Traditional resistance training requires the application of heavy training loads and intensity of 70-100% of 1 repetition maximum (1-RM), whereas low-load BFRT (LL-BFRT) utilises significantly lower loads and training intensities of between 20-40% of 1-RM, which may be more appropriate for some clinical populations unable to train with heavy resistance (Krzysztofik et al., 2019;Kataoka et al., 2022;Hill et al., 2020;Shiromaru et al., 2019). ...
Preprint
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Tendinopathy is chronic tendon disease which can cause significant pain and functional limitations for individuals and collectively place a tremendous burden on society. Resistance training has long been considered the treatment of choice in the rehabilitation of chronic tendinopathies, with both eccentric and heavy slow resistance training demonstrating positive clinical effects. The application of progressive tendon loads during rehabilitation is essential to not compromise tendon healing, with the precise dosing parameters of resistance training and external loading a critical consideration. Blood-flow restriction training (BFRT) has become an increasingly popular method of resistance training in recent years and has been shown to be an effective method for enhancing muscle strength and hypertrophy in healthy populations and in musculoskeletal rehabilitation. Traditional resistance training for tendinopathy requires the application of heavy training loads, whereas BFRT utilises significantly lower loads and training intensities, which may be more appropriate for certain clinical populations. Despite evidence confirming the positive muscular adaptations derived from BFRT and the clinical benefits found for other musculoskeletal conditions, BFRT has received a dearth of attention in tendon rehabilitation. Therefore, the purpose of this narrative review was threefold: firstly, to give an overview and analysis of the mechanisms and outcomes of BFRT in both healthy populations and in musculoskeletal rehabilitation. Secondly, to give an overview of the evidence to date on the effects of BFRT on healthy tendon properties and clinical outcomes when applied to tendon pathology. Finally, a discussion on the clinical utility of BFRT and its potential applications within tendinopathy rehabilitation, including as a compliment to traditional heavy-load training, will be presented.
... Comparing these results with previous meta-analyses, Hughes et al. (58) and Lixandrão et al. (21) found significant differences in favor of HIRT in the general population. In addition, the study by Centner et al.(29) in the population over 50 years old also found significant differences in favor of HIRT. ...
Article
Objective To analyze the effectiveness of the blood flow restriction training in improving muscle strength and physical performance in older adults. Data Sources A systematic review and meta-analysis of randomized control trials was conducted. The Cochrane Library, PubMed, Web of Sciences, PEDro, Scopus and ScienceDirect databases were systematically searched. Study Selection Articles were included if participants were 60 years or older and were considered as healthy. Data Extraction The search strategy found a total of 363 studies. Finally, ten articles were included in the systematic review, with a total of 278 healthy older adults analyzed. Data Synthesis The main results of the meta-analysis showed a statistical difference of muscle strength in favor of blood flow restriction training when compared with conventional, and no statistical differences with high-intensity resistance training. Physical performance showed a non-statistical difference between the blood flow restriction training group and conventional training group and no training group. Conclusions Blood flow restriction training is an interesting alternative to high-intensity strength training for improving muscle strength in older people who cannot perform high-load exercises.
... Exercise training with blood flow restriction (BFR) is characterized by the application of an inflatable cuff to the proximal portion of the limb aiming to decrease venous return to a muscle [1]. The limited blood supply is an important trigger for muscle adaptations and, thus, it is a potent therapy to improve muscle mass, strength, and functionality even when it is applied with low loads; leading to low musculoskeletal overload, important for older adults [2][3][4][5]. Resistance exercise with BFR (RE-BFR) increases the strength and muscle mass of elderly individuals; however, aerobic exercise with BFR (AE-BFR) has additional benefits, increasing muscle mass, strength [6], and also cardiorespiratory fitness [7,8]. It suggests AE-BFR might be preferred compared to RE-BFR, considering its comprehensive benefits. ...
Article
Objectives In addition to the increase in muscle mass and strength promoted by resistance exercise with blood flow restriction (RE-BFR), aerobic exercise with BFR (AE-BFR) improves aerobic fitness. However, acute cardiovascular responses to these exercise protocols are quite unknown and a comparison between RE-BFR and AE-BFR has never been shown. Equipment and methods A cross-over design was used to compare the acute cardiovascular effects of RE-BFR and AE-BFR in healthy older adults. Seventeen older adults underwent the RE-BFR protocol in leg press 45°, with 30% of 1RM and AE-BFR protocol in the treadmill, with 40% of VO2 max; both protocols included continued BFR of 50% until the end of the exercise. The cardiovascular variables were continually recorded from 15 min before exercise until 30 min post each exercise session, thorough finger photoplethysmography. Results During the interventions no adverse events were reported. The AE-BFR caused lower systolic and diastolic blood pressure peaks, faster heart rate recovery, without increase peripheral vascular resistance, while had a higher cardiac output peak.
... Returning astronauts are load compromised and perform initial reconditioning exercises at a low intensity to minimize the risk of injury 96 . BFR exercise is an effective rehabilitation tool for muscular, aerobic and functional adaptations in load compromised populations with minimized risk of injury [69][70][71] . It could be used to maximize adaptations to low intensity exercise, minimize risk of injury and treat transit-induced injuries during postflight reconditioning of astronauts on Earth and another planet (Fig 3). ...
Article
During spaceflight missions, astronauts work in an extreme environment with several hazards to physical health and performance. Exposure to microgravity results in remarkable deconditioning of several physiological systems, leading to impaired physical condition and human performance, posing a major risk to overall mission success and crew safety. Physical exercise is the cornerstone of strategies to mitigate physical deconditioning during spaceflight. Decades of research have enabled development of more optimal exercise strategies and equipment onboard the International Space Station. However, the effects of microgravity cannot be completely ameliorated with current exercise countermeasures. Moreover, future spaceflight missions deeper into space require a new generation of spacecraft, which will place yet more constraints on the use of exercise by limiting the amount, size and weight of exercise equipment and the time available for exercise. Space agencies are exploring ways to optimise exercise countermeasures for spaceflight, specifically exercise strategies that are more efficient, require less equipment and are less time-consuming. Blood flow restriction exercise is a low intensity exercise strategy that requires minimal equipment and can elicit positive training benefits across multiple physiological systems. This method of exercise training has potential as a strategy to optimise exercise countermeasures during spaceflight and reconditioning in terrestrial and partial gravity environments. The possible applications of blood flow restriction exercise during spaceflight are discussed herein.
... Once our study was carried out with a healthy population, caution is necessary to extrapolate our results for injured populations or patients in rehabilitation. However, since both methods are commonly applied during rehabilitation periods, some future directions may be indicated: (1) it is important to highlight that although smaller, NES-BFR produced significant increases in muscle CSA through electrically evoked muscle contractions, which suggest that this method may represent an alternative for when the patient cannot perform dynamic voluntary contractions and (2) in case the patient is able to perform external load exercises, LL-BFR may be employed to produce even larger increases in the muscle CSA. ...
Article
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Context: Low-load resistance training (LL) and neuromuscular electrostimulation (NES), both combined with blood flow restriction (BFR), emerge as effective strategies to maintain or increase muscle mass. It is well established that LL-BFR promotes similar increases in muscle cross-sectional area (CSA) and lower rating of perceived exertion (RPE) and pain compared with traditional resistance training protocols. On the other hand, only 2 studies with conflicting results have investigated the effects of NES-BFR on CSA, RPE, and pain. In addition, no study directly compared LL-BFR and NES-BFR. Objective: The aim of the study was to compare the effects of LL-BFR and NES-BFR on vastus lateralis CSA, RPE, and pain. Individual response for muscle hypertrophy was also compared between protocols. Design: Intrasubject longitudinal study. Setting: University research laboratory. Intervention: Fifteen healthy young males (age = 23 [5] y; weight = 77.6 [11.3] kg; height = 1.76 [0.08] m). Main outcome measures: Vastus lateralis CSA was measured through ultrasound at baseline (pre) and after 20 training sessions (post). The RPE and pain responses were obtained through modified 10-point scales, handled during all training sessions. Results: Both protocols demonstrated significant increases in muscle CSA (P < .0001). However, the LL-BFR demonstrated significantly greater CSA changes compared with NES-BFR (LL-BFR = 11.2%, NES-BFR = 4.6%; P < .0001). Comparing individual increases in CSA, 12 subjects (85.7% of the sample) presented greater muscle hypertrophy for LL-BFR than for the NES-BFR protocol. In addition, LL-BFR produced significantly lower RPE and pain responses (P < .0001). Conclusions: The LL-BFR produced significantly greater increases in CSA with significant less RPE and pain than NES-BFR. In addition, LL-BFR resulted in greater individual muscle hypertrophy responses for most subjects compared with NES-BFR.
... Neuromuscular electrical stimulation and blood flow restriction therapy are useful adjuncts to exercise to improve muscle activation and strengthening, reduce muscular atrophy, and possibly mitigate bone density loss following surgery. [102][103][104][105][106] As recovery progresses, the therapy program should evolve in both structure and intensity to continue to promote gains in strength, stability, coordination, and cardiovascular fitness, as tolerated by knee symptoms. Serial physical performance testing, conducted on 3-4 month intervals, provides objective criteria to guide care progression and decision making for return to activity and/or sport. ...
Article
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Multiligament knee injuries are complex injuries that must be addressed with a comprehensive diagnostic workup and treatment plan. Multiligament injuries are commonly observed with concomitant meniscal, chondral, and neurovascular injuries, requiring a thorough clinical assessment and radiographic evaluation. Due to the higher failure rates associated with knee ligament repair following multiligament knee injury, the current literature favors single-stage anatomic knee reconstructions. Recent studies have also optimized graft sequencing and reconstruction tunnel orientation to prevent graft elongation and reduce the risk of tunnel convergence. In addition, anatomic-based ligament reconstruction techniques and usage of suture anchors now allow for early postoperative knee motion without the risk of stretching out the graft. Rehabilitation following multiligament knee reconstruction should begin on postoperative day one and typically requires 9-12 months. The purpose of this article is to review the latest principles of the surgically relevant anatomy, biomechanics, evaluation, treatment, rehabilitation, and outcomes of multiligament knee injuries.
... In another meta-analysis, the effects of BFR exercises applied between 2-16 weeks on musculoskeletal diseases were examined, and it was shown that 8-week exercises showed positive improvements in muscle architecture, strength, and endurance. In addition, it has been reported that the BFR method can be a clinically effective tool in the rehabilitation of the musculoskeletal system (Hughes et al., 2017). ...
Conference Paper
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Abstract Introduction: Blood flow restriction (BFR) is a method based on complete restriction of venous blood flow and partial restriction of arterial blood flow with pneumatic cuff during lowintensity exercises. Restriction creates hypoxic environment, resulting in low mechanical and high metabolic stress in muscle compared to high-intensity exercise. The effects such as increased strength and hypertrophy occur by the induction of various mechanisms. The BFR is applied in different conditions as following: In postoperative period, in cases which highintensity exercises cannot be tolerated or are contraindicated, in neurological/cardiopulmonary diseases, musculoskeletal injuries. Objective: This review aims to summarize the existing literature on the effects of BFR used in the treatment of different knee pathologies. Method: A literature search was carried out on MEDLINE. “Blood flow restriction” and “knee” were used as keywords. The studies published in last five-years with full text, which consisted of humans with any knee pathologies, with control group, applied BFR as treatment were included. Case studies and reviews were excluded. Results: The preliminary review consisted of 41 studies, and 14 of them (osteoarthritis, anterior cruciate ligament reconstruction, meniscus and cartilage repair, arthroscopy, rheumatologic diseases, patellofemoral/anterior knee pain) were included in the review after the detailed screening. The studies reported significant improvements in strength (10 of 14 (%71.42)), pain (7), muscle architecture/thickness (6 of 7 (86%)), endurance (1), functionality (6 of 8 (75%)) and quality of life (2 of 5 (40%)). No side-effects were reported in the studies. Conclusion: The rehabilitation of knee is aimed to reduce pain, increase painless range of motion, strength, and functionality. In the literature, it is reported that low-intensity BFR exercises may obtain favorable improvements similar/superior to high-intensity exercises, the pain in joints during the exercises is reduced, and good compliance with treatment is obtained. There is a need for studies investigating the effectiveness and application parameters of BFR in different pathologies.
... BFR training has started to infiltrate rehabilitation settings and has shown promising results so far. Although this review is primarily focused on the potential uses of BFR training, and how to safely implement and prescribe the technique, in populations with OA, Hughes et al. (16) recently published a systematic review and meta-analysis on the research into BFR usage across a range of musculoskeletal maladies. One study compared BFR training and traditional rehabilitation programming in postoperative ACL reconstruction patients (19). ...
... Επίσης, ο συγκεκριμένος τύπος άσκησης που δεν απαιτεί υψηλά φορτία είναι μια εφικτή μέθοδος για την ΚΑ, δεδομένου ότι οι συστάσεις της Αμερικανικής Καρδιολογικής Εταιρείας προτείνουν χαμηλότερα φορτία και ένταση και, συνεπώς, η άσκηση BFR θα μπορούσε να είναι ένα πολύτιμο εργαλείο στα χέρια των θεραπευτών, καθώς μπορεί να επιταχύνει την αποκατάσταση των ασθενών, ελαχιστοποιώντας τα λειτουργικά ελλείμματα της μυϊκής δύναμης και της μυϊκής μάζας. [80][81][82][83][84] ...
Article
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Valvular heart disease (VHD) is a major cause of mortality and morbidity, and its prevalence increases with age. VHD is mainly degenerative in origin, and it is widespread in the developed countries, following rheumatic heart disease. In most cases of mitral valve (MV) disease, surgery is needed to either repair or replace the MV. Cardiac rehabilitation (CR), with exercise as the main component, contributes significantly to the quality of the life (QoL) in patients who have undergone MV surgery, and decreases morbidity and mortality. The role of the physiotherapist, as part of the scientific CR team, is to evaluate and prescribe individualized rehabilitation programs for patients following MV surgery. Cardiorespiratory physiotherapy is an evidence-based essential rehabilitation procedure for these patients. Innovative therapeutic approaches, such as e-Ηealth applications, telerehabilitation, home-based exercise, aquatic exercise training, and neuromuscular electrical stimulation (NMES) training, all appear to be beneficial alternative CR techniques.
... Blood flow restriction training (BFRT) is a method of resistance training which utilizes pneumatic cuffs or straps around a limb to partially restrict arterial blood flow, while simultaneously occluding venous outflow until the cessation of cuff pressure (Lorenz et al., 2021). BFRT also known as occlusion, hypoxic or Kaatsu training has become increasingly popular over the last decade as a method for enhancing strength gains in healthy populations such as athletes and more recently as a rehabilitation tool in those with musculoskeletal pathologies (Hughes et al., 2017;Barber-Westin and Noyes, 2019;Nitzsche et al., 2021). For example, BFRT has been found to be an efficacious method for increasing strength gains and muscle hypertrophy in rehabilitation following surgery for anterior cruciate ligament (ACL) rupture (Hughes et al., 2018;Caetano et al., 2021). ...
Article
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Objective: To identify current evidence on blood flow restriction training (BFRT) in tendon injuries and healthy tendons, evaluating physiological tendon effects, intervention parameters and outcomes. Methods: This scoping review was reported in accordance with the PRISMA Extension for Scoping Reviews (PRISMA-ScR). Databases searched included MEDLINE, CINAHL, AMED, EMBase, SPORTDiscus, Cochrane library (Controlled trials, Systematic reviews), and five trial registries. Two independent reviewers screened studies at title/abstract and full text. Following screening, data was extracted and charted, and presented as figures and tables alongside a narrative synthesis. Any study design conducted on adults, investigating the effects of BFRT on healthy tendons or tendon pathology were included. Data were extracted on physiological tendon effects, and intervention parameters and outcomes with BFRT. Results: 13 studies were included, 3 on tendinopathy, 2 on tendon ruptures and 8 on healthy Achilles, patellar, supraspinatus and vastus lateralis tendons. A variety of outcomes were assessed, including pain, function, strength, and tendon morphological and mechanical properties, particularly changes in tendon thickness. BFRT intervention parameters were heterogeneously prescribed. Conclusion: Despite a dearth of studies to date on the effects of BFRT on healthy tendons and in tendon pathologies, preliminary evidence for beneficial effects of BFRT on tendons and clinical outcomes is encouraging. As BFRT is a relatively novel method, definitive conclusions, and recommendations on BFRT in tendon rehabilitation cannot be made at present, which should be addressed in future research, due to the potential therapeutic benefits highlighted in this review.
... We define "eccentrics" simply as a lengthening muscle contraction and mention sub-maximal eccentrics as it is recommended that this mode of exercise be used in the presence of muscle pain, detraining, or after immobilization [18]. Blood flow restriction is recommended as an adjunct to local exercise as it seems to have a positive effect on hypertrophy, strength, and function using lower loads so may enhance a post-operative or immediate post-injury approach [19]. ...
Article
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Rehabilitation professionals prescribe exercise regularly with the goals of decreasing pain, increasing function, and returning athletes to competition. To maximize the effect of an exercise intervention, the program must be individualized and in context for the athlete considering biopsychosocial aspects of care. Current models of exercise prescription may not be ideal considering that less than 50% of injured athletes return to their pre-injury level. Advice on exercise prescription has been offered in the past, but the paradigms are either not user friendly or user friendly but linear, based on phases of recovery. As such, there is a need for a more flexible exercise prescription paradigm that should improve the individuality of exercise prescription. In this Current Opinion, we offer a user-friendly construct-oriented paradigm designed to facilitate the creation of individualized exercise programs for athletes.
... Several case reports have been published indicating the occurrence of rhabdomyolysis following an acute bout of BFR-RE [16,45,84]. Although a relatively small number of adverse events have been reported, it is recommended that an approach which includes progressive implementation and individualized cuff pressures be implemented to limit risk [40]. ...
Article
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Purpose The purpose of this study was to examine the response of myokines to blood-flow restricted resistance-exercise (BFR-RE) in younger and older males before and after completing a 12-week resistance-training program. Methods There were 8 younger (24.8 ± 3.9 yrs) and 7 older (68.3 ± 5.0 yrs) untrained male participants completed this study. Anthropometric and maximal strength (1RM) measurements were collected before and after a 12-week, supervised, progressive full-body resistance-training program. As well, an acute bout of full-body BFR-RE was performed with venipuncture blood samples collected before and immediately following the BFR-RE, followed by sampling at 3, 6, 24 and 48 h. Results The 12-week training program stimulated a 32.2% increase in average strength and 30% increase in strength per kg of fat free mass. The response of particular myokines to the acute bout of BFR-RE was influenced training status (IL-4, untrained = 78.1 ± 133.2 pg/mL vs. trained = 59.8 ± 121.6 pg/mL, P = 0.019; IL-7, untrained = 3.46 ± 1.8 pg/mL vs. trained = 2.66 ± 1.3 pg/mL, P = 0.047) or both training and age (irisin, P = 0.04; leukemia inhibitory factor, P < 0.001). As well, changes in strength per kg of fat free mass were correlated with area under the curve for IL-4 ( r = 0.537; P = 0.039), IL-6 ( r = 0. 525; P = 0.044) and LIF ( r = − 0.548; P = 0.035) in the untrained condition. Conclusion This study identified that both age and training status influence the myokine response to an acute bout of BFR-RE with the release of IL-4, IL-6 and LIF in the untrained state being associated with changes in strength per kg of fat free mass.
... However, this intervention is already successfully used in musculoskeletal rehabilitation. A systematic review with blood flow restriction in addition with low-impact training showed a moderate effect on muscle strength gain compared to training alone in patients with knee osteoarthritis, ligament injuries or myositis and in older patients who are prone to sarcopenia [47]. Positive effects on the microcirculation can therefore indirectly protect the muscles, because temporary reduction in blood flow leads to a counter-reaction of the body and, in combination with exercise, even if it is low-dose, can support the maintenance or build-up of muscle mass [41]. ...
Article
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Early mobilization, which includes active / passive motion in bed along with mobilization out of bed, is recommended to prevent the development of intensive care unit acquired-weakness (ICU-AW) for patients with critical illness on the intensive care unit. To date, the impact of passive motion of the lower extremities in sedated and ventilated patients remains unclear. The aim of the study is to systematically review and summarize the currently available randomized controlled trials in English or German language on the impact of passive motion of the lower extremities in sedated and ventilated patients ≥ 18 years in the intensive care unit on musculature, inflammation and immune system and the development of intensive care unit-acquired weakness and to evaluate the replicability of interventions and the methodological quality of included studies. A systematic literature search was performed up to 20th February 2022 in the databases Medline, Embase, Cochrane Library, CINAHL and PEDro. The description of the intervention (TIDieR checklist) and the methodological quality (Downs and Black checklist) were assessed. Five studies were included in the qualitative syntheses. On average, the studies were rated with 6.8 out of 12 points according to the TIDieR checklist. For the methodological quality an average of 19.8 out of 27 points on the Downs and Black checklist was reported. The results of included studies indicated that muscle loss may be reduced by passive manual movement, passive cycling and passive motion on a continuous passive motion-unit. In addition, positive effects were reported on the reduction of nitrosative stress and the immune response. The impact on the development of ICU-AW remains unclear. In conclusion, passive movement show a slight tendency for beneficial changes on cellular level in sedated and ventilated patients in the ICU within the first days of admission, which may indicate a reduction of muscle wasting and could prevent the development of ICU-AW. Future randomized controlled trials should use larger samples, use complete intervention description, use a comparable set of outcome measures, use rigorous methodology and examine the effect of passive motion on the development of ICU-AW.
... Therefore, L-BFR is expected to have a low level of side effects such as falls and the exacerbation of knee osteoarthritis. Besides, its safety and efficacy have been reported in various rehabilitation studies in middle-aged and older adults (cardiac rehabilitation [86], clinical musculoskeletal rehabilitation [87], medial femoral condylar osteonecrosis cases [88], meniscectomy [89], Churg Strauss syndrome [90], etc.). ...
Article
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Resistance training is an extremely beneficial intervention to prevent and treat sarcopenia. In general, traditional high-load resistance training improves skeletal muscle morphology and strength, but this method is impractical and may even reduce arterial compliance by about 20% in aged adults. Thus, the progression of resistance training methods for improving the strength and morphology of muscles without applying a high load is essential. Over the past two decades, various resistance training methods that can improve skeletal muscle mass and muscle function without using high loads have attracted attention, and their training effects, molecular mechanisms, and safety have been reported. The present study focuses on the relationship between exercise load/intensity, training effects, and physiological mechanisms as well as the safety of various types of resistance training that have attracted attention as a measure against sarcopenia. At present, there is much research evidence that blood-flow-restricted low-load resistance training (20–30% of one repetition maximum (1RM)) has been reported as a sarcopenia countermeasure in older adults. Therefore, this training method may be particularly effective in preventing sarcopenia.
Article
Exploring acute neuromuscular fatigue induced by different modalities of resistance exercise would help understand the adaptation subsequent to specific training programs. Therefore, we investigated the acute impact of high-intensity and low-intensity blood flow-restricted resistance exercise on the development of explosive torque throughout the torque-time curve. Seventeen healthy, young participants were included in a randomized, counterbalanced within-subjects design study, in which participants underwent two experimental conditions, separated by a 1-wk period. Low-intensity blood-flow restricted exercise and high-intensity resistance exercise were performed using dynamic elbow flexion at 20 and 75% of 1 repetition maximum, respectively. Maximal voluntary contraction (MVC) and the sequential rate of torque development (absolute and relative) were measured before and after exercise. Both protocols elicited a similar decrement in MVC (~ 25%) and in the peak rate of torque development after exercise (~ 45%). The absolute rate of torque development (0-50 and 50-100 ms) was also reduced (p<0.05) similarly between conditions. After normalizing torque values to MVC, this was only sustained for the rate of torque development 0-50ms (p<0.05). We found that both exercise protocols induced similar acute attenuation of the absolute rate of torque development up to the first 100 ms of MVC. We also demonstrated that the reduction in the rate of torque development between 50-100ms (in both protocols) was largely explained by an acute deficit in muscle strength post-exercise. Conversely, the impact of each protocol on the first 50ms of muscle torque did not depend on lower levels of muscle strength after exercise.
Article
Proximal tibial osteotomies are an effective treatment option for addressing knee instability secondary to alignment-based overload on ligamentous structures. Proximal tibial osteotomies effectively alter the mechanical axis to redistribute forces across the knee, resulting in improved stability and overall function. Factors such as tibial slope and coronal alignment can affect the biomechanical forces experienced by the ligaments in the knee. This becomes especially important when treating recurrent instability following primary reconstruction of one or more of the ligaments of the knee. A variety of osteotomy procedures exist to address a wide range of alignment disorders. These include proximal tibial closing wedge osteotomies, anterolateral opening wedge osteotomies, anterolateral opening wedge osteotomies, and proximal tibial medial opening wedge osteotomies. Recently, the indications of medial opening wedge osteotomies have been expanded to include treatment of chronic central and posterolateral ligament instability. Early rehabilitation in the recovery phase should focus on limb protection, symptom management, protected range of motion (ROM), quadriceps muscle activation, and monitoring for overall patient well-being. Clear guidelines for safe quadriceps training progressions following osteotomy do not exist due to the paucity of biomechanical literature. The patient should gradually progress through the transition and rebuild phases of recovery over the first 24 weeks following surgery. Patients may not progress into the restore phase of rehabilitation as this population typically completes the second stage of the two-stage ligamentous reconstruction during the latter half of the Rebuild phase once sufficient healing from the first procedure has occurred. Currently, data regarding clinical outcomes and return to sport data following PTO for knee instability is limited.
Article
Resistance training associated with partial blood flow restriction confers functional benefits to patients with different clinical profiles. This study aimed to investigate, through a systematic review, the effects of resistance exercise with partial blood flow restriction on strength, muscle volume and pain in patients with knee osteoarthritis. The studies were selected from the following databases: LILACS, PubMed and Physiotherapy Evidence Database (PEDro). The descriptors used were Blood Flow Restriction AND Knee Osteoarthritis AND Clinical Trial AND Exercise. The methodological quality was determined using the PEDro scale. Four studies were included in the review. The findings indicated that low-intensity resistance training with partial blood flow restriction promoted similar effects to conventional training programs on the knee extension strength, quadriceps femoris muscle volume and pain of patients with knee osteoarthritis. On the other hand, in one study there was an increase in the knee extension strength, and in another, there was a reduction in pain intensity after blood flow restriction training. Despite the scarcity of studies on the subject and the small samples of clinical trials, findings of these studies suggested that addition of partial blood flow restriction to low-intensity resistance training programs emerges as a potential rehabilitation tool, considering similar effects to conventional training programs.
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Background Lower limb muscle strength symmetry has been suggested as an essential criterion for the safe return to sports after anterior cruciate ligament (ACL) reconstruction. Limited evidence is available regarding the most effective intervention to achieve symmetry after reconstruction with contralateral bone–patellar tendon–bone (BPTB) graft. Purpose To verify whether unilateral isotonic resistance exercise is more effective than bilateral exercise for obtaining postoperative functional and muscular strength symmetry between the donor limb and reconstructed limb for patients who received BPTB graft. Study Design Randomized controlled trial; Level of evidence, 1. Methods A total of 88 patients were randomly divided into a control group (n = 44) and an intervention group (n = 44). All participants performed an 8-week exercise program starting at the beginning of the fourth postoperative month and were evaluated before and after the program. The control group performed bilateral exercises, and the intervention group performed unilateral exercises for the donor limb only (the limb with the greatest disability). The primary outcome was muscle strength (peak torque and hamstrings to quadriceps [H:Q] ratio), and the secondary outcomes were range of motion (ROM; goniometry), KT-1000 arthrometer side-to-side difference in anteroposterior knee laxity, and objective (single-leg hop test) and subjective (Lysholm score) functionality. Results Both groups improved significantly from before to after the exercise program. The improvements were significantly greater in the intervention group regarding peak torque, H:Q ratio, flexion ROM, single-leg hop test, and Lysholm score in the donor limb ( P < .001 for all), and the improvements were significantly greater in the control group regarding peak torque and single-leg hop test in the reconstructed limb ( P < .001 for both). Comparison between the groups showed significantly increased symmetry regarding peak torque, H:Q ratio, and single-leg hop test in the intervention group compared with the control group ( P < .001), with large effect sizes (>0.80) except for the H:Q ratio. Conclusion Although postoperative, bilateral, isotonic resistance exercise provided better strength gains to the reconstructed limb, unilateral exercise was more effective in obtaining functional and muscle strength between-limb symmetry in patients who underwent ACL reconstruction with contralateral BPTB graft. Registration Brazilian Registry of Clinical Trials (number RBR-22rnjh).
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• Gain a better understanding of the purpose of occlusion training, how to properly utilize it, and when to use it with your clients. • Understand the contraindications to occlusion training and know some of the possible health risks associated with it.
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The utilization of blood flow restriction has garnished considerable attention due to its widespread application and benefits that include strength enhancement, muscle hypertrophy, and increased level of function for specific populations. Blood flow restriction induces a hypoxic environment within a muscle group, initiating a metabolic cascade that stimulates muscle protein synthesis, altered gene regulation of muscle satellite cells, and increased muscle fiber recruitment, ultimately resulting in improved strength and endurance. When using blood flow restriction, consideration of the individual patient, occlusion pressure, cuff width, and cuff size are paramount. Blood flow restriction has been proven to be a consistently safe and effective tool for augmenting rehabilitative regimens for the upper and lower extremity.
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Introdution: Sarcopenic obesity (SO) is defined as the condition in which obesity is accompanied by decreased skeletal muscle mass. People with SO may have synergistic effect due to obesity and sarcopenia, with increased cardiovascular risk. Objective: To describe the findings of the literature on sarcopenic obesity and their impact on hypertension. Method: Electronic database search: MED- LINE, CINAHL, LILACS, Cochrane, Scopus and Web of Science, using combinations of Boolean operators and descriptors: “sarcopenic obesity” OR “sarcopenia” AND “hypertension” OR “metabolic syndrome” in the summary. Results: It was possible to verify the association of SO with hypertension, but the prevalence of hypertensive people in the sarcopenic obese population has a wide variation, mainly in cross-sectional studies. Conclusion: The lack of consensus on the definition of SO endangers clinical practice and research on its true impact on hypertension. Keywords: sarcopenic obesity, sarcopenia, hypertension, metabolic syndrome
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El entrenamiento con restricción al flujo sanguíneo es un método de entrenamiento que implica la aplicación de un dispositivo de envoltura próxima al músculo a entrenar, y realizar repeticiones con cargas inferiores a las recomendadas tradicionalmente para lograr hipertrofia y el aumento de fuerza muscular. Este entrenamiento ha ganado popularidad dentro de la kinesiología gracias a que permite alcanzar dichos objetivos en pacientes don-de no es posible realizar cargas mayores debido a su condición clínica. El objetivo de este paso a paso es describir el procedimiento para su aplicación y detallar las contraindicaciones que presenta la técnica.
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Após o retorno parcial das aulas nas Escolas Estaduais do Estado de São Paulo, foi visível perceber o aumento do peso corporal em estudantes e a inatividade física, mensurada nas aulas de Educação Física em Birigui/SP. Diante do exposto, este artigo consiste em uma pesquisa de campo que discute a seguinte questão: o peso corporal que os alunos adquiriram durante a quarentena tem correlação com seu respectivo batimento cardíaco? O objetivo geral deste trabalho foi verificar possível correlação entre Índice de Massa Corporal (IMC) e o valor de batimento cardíaco obtido após um teste de corrida de 50 metros. A metodologia aplicada foi quantitativa, transversal e explicativa, na qual os estudantes foram aferidos a estatura, o peso corporal – para o IMC – e seus batimentos cardíacos antes e após a execução do exercício. A amostra da pesquisa é construída com 76 estudantes do 6º ao 8º ano (entre 11 e 14 anos), correspondendo a cerca de 1,6% do total de estudantes do Ensino Fundamental II de Birigui. Resultados: as características de composição do Índice de Massa Corporal têm relação com a frequência cardíaca obtida no final da execução do exercício, porém apresentando médias normais nesta população, contudo, cerca de 6,84% do total de adolescentes pesquisados, estão inaptos, ou seja, não tem atividade física fora da escola, apenas nas aulas de Educação Física semanais. Conclusão: pode-se concluir que 5 dentre 76 estudantes são inaptos fisicamente em Birigui/SP.
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During aging, genetic and environmental factors carry an increased risk of diseases that facilitate the loss of function. High-intensity resistance training has been shown to lead to health benefits in older adults, however, its use is limited in this population. Recently, hypoxic resistance training (HRT) has been presented as a viable alternative in rehabilitation therapy for older adults, however, information is scarce in this regard. Thus, the objective of this study was to collect current knowledge about HRT in older adults, as well as the benefits for their health. To do this, a selective search was carried out for articles published in the last 6 years on the effects of HRT in older people in the Pubmed database. The search resulted in 227 articles, of which 18 were selected for this review. Three types of training were identified: blood flow restriction therapy (BFRT), resistance training in hypobaric hypoxia (RTHH), and resistance training in normobaric hypoxia (RTNH). From the information collected, we can indicate that TRFS offers greater positive effects on strength gain and muscle hypertrophy, while there is little evidence of RTHH and RTNH in older people. Finally, we express the need for more studies to evaluate the safety of this intervention in health in this age group.
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The purpose of this study was to determine the adaptive response of ratings of perceived exertion (RPE) and pain over six consecutive training sessions. Thirty subjects were assigned to either a blood flow restricted training group (BFRT) or a high intensity group (HIT). BFRT group performed four sets (30+15+15+15, respectively) of unilateral leg extension at an intensity of 20% one repetition maximum (1RM) while a restrictive cuff was applied to the most proximal part of the leg. HIT group performed 3 sets of eight repetitions with 85%1RM. RPE and pain were assessed following every exercise set. Per-session RPE and pain were considered as the average value throughout all sets. RPE dropped from Session 4 following HIT (8.5 to 7.6, p<0.05) and from Session 5 following BFRT (7.4 to 6.0, p<0.01). Perceived pain dropped from Session 5 in both groups (HIT: 6.2 to 5.4 and BFRT: 8.1 to 6.3, p<0.01). No between-group differences were found at any time point. In summary, BFRT induces a high perceptual response to training. However, this perceptual response is rapidly attenuated, leading to values similar to those experienced during HIT. Low load BFRT should not be limited to highly motivated individuals only. Copyright (C) 2016 by the National Strength & Conditioning Association.
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Purpose The objective of this study was to evaluate whether women with knee osteoarthritis performing a rehabilitation programme consisting of low-load exercises combined with PVO exhibited the same results in changes in quadriceps strength, pain relief, and functional improvement when compared to women receiving a programme consisting of high-load exercises without PVO. Methods Thirty-four women (mean age, 61 years) with a diagnosis of knee osteoarthritis were randomly assigned to a conventional or occlusion group. The women in the conventional group (n = 17) performed a 6-week quadriceps strengthening and stretching programme using a load around 70 % of the 1-repetition maximum (RM). The women in the occlusion group (n = 17) performed the same programme, however, only using a load around 30 % of the 1-RM, while PVO was induced. The PVO was achieved using a pressure cuff applied to the upper third of the thigh and inflated to 200 mmHg during the quadriceps exercise. An 11-point Numerical Pain Rating Scale (NPRS), the Lequesne questionnaire, the Timed-Up and Go (TUG) test, and muscle strength measurement using a hand-held dynamometer were used as outcome measures at baseline (pretreatment) and at the end of the 6-week of treatment. Pain, using the NPRS, was also assessed when performing the quadriceps exercises during the exercise sessions. Results At baseline, demographic, strength, pain, and functional assessment data were similar between groups. Patients from both the conventional and occlusion groups had a higher level of function (Lequesne and TUG test), less pain (NPRS), and higher quadriceps strength at the 6-week evaluation when compared to baseline (all P < 0.05). However, the between-group analysis showed no differences for all outcomes variables at posttreatment (n.s.). Patients in the occlusion group experienced less anterior knee discomfort during the treatment sessions than those in the high-load exercise group (P < 0.05). Conclusion A rehabilitation programme that combined PVO to low-load exercise resulted in similar benefits in pain, function, and quadriceps strength than a programme using high-load conventional exercise in patients with knee osteoarthritis. However, the use of PVO combined with low-load exercise resulted in less anterior knee pain during the training sessions. Level of evidence I.
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to the editor: We read with interest the article by Spranger et al. ([7][1]) in which the authors discussed the exercise pressor reflex in response to blood flow restriction (BFR) exercise. Within, the authors cite an impracticality of standardizing cuff pressure due to differences in cuff width,
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Abstract There has been much debate as to optimal loading strategies for maximising the adaptive response to resistance exercise. The purpose of this paper therefore was to conduct a meta-analysis of randomised controlled trials to compare the effects of low-load (≤60% 1 repetition maximum [RM]) versus high-load (≥65% 1 RM) training in enhancing post-exercise muscular adaptations. The strength analysis comprised 251 subjects and 32 effect sizes (ESs), nested within 20 treatment groups and 9 studies. The hypertrophy analysis comprised 191 subjects and 34 ESs, nested with 17 treatment groups and 8 studies. There was a trend for strength outcomes to be greater with high loads compared to low loads (difference = 1.07 ± 0.60; CI: -0.18, 2.32; p = 0.09). The mean ES for low loads was 1.23 ± 0.43 (CI: 0.32, 2.13). The mean ES for high loads was 2.30 ± 0.43 (CI: 1.41, 3.19). There was a trend for hypertrophy outcomes to be greater with high loads compared to low loads (difference = 0.43 ± 0.24; CI: -0.05, 0.92; p = 0.076). The mean ES for low loads was 0.39 ± 0.17 (CI: 0.05, 0.73). The mean ES for high loads was 0.82 ± 0.17 (CI: 0.49, 1.16). In conclusion, training with loads ≤50% 1 RM was found to promote substantial increases in muscle strength and hypertrophy in untrained individuals, but a trend was noted for superiority of heavy loading with respect to these outcome measures with null findings likely attributed to a relatively small number of studies on the topic.
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