Динамика аппендикулярной массы мышц после силовых тренировок с ограничением кровотока у лиц с метаболическим синдромом

Introduction. Metabolic syndrome is defined as a pathological condition characterized by abdominal obesity, hypertension, dyslipidemia, and impaired glucose tolerance. Insulin resistance is hypothesized to underlie metabolic syndrome. Modern studies, including Mendelian randomization, have demonstrated that muscle strength and muscle mass may play an important role in the mechanisms of insulin resistance. Aim. To establish the relationship between relative upper limb muscle strength and triglyceride/glucose index, and to evaluate the effects of different resistance exercise regimens on alternative measures of insulin resistance in men with metabolic syndrome. Materials and methods. At the first stage of the study, 216 men aged from 25 to 50 years were examined. The relative muscle strength of the upper limbs in the bench press exercise and the triglyceride/glucose index were assessed. At the second stage, a randomized controlled trial was conducted, for which 60 men who met the criteria for metabolic syndrome. Men with metabolic syndrome were divided into three groups: low-intensity strength training with blood flow restriction (n = 20), high-intensity strength training (n = 20), low-intensity strength training without blood flow restriction (n = 20). Training was carried out 2 times a week for 12 weeks. Before and after the study, the triglycerides/glucose index, the ratio of triglycerides to high-density lipoproteins, and the combination of the triglycerides/glucose index with body mass index were assessed. Results and discussion. It was found that the relative muscle strength of the upper limbs was inversely proportional to the triglycerides/glucose index (r = –0.52; p 0.05) in the examined men. After 12 weeks of resistance training, statistically significant reductions in triglyceride/glucose index, triglyceride/high-density lipoprotein ratio, and triglyceride/glucose index/body mass index combination were found for the low-intensity resistance training with blood flow restriction and high-intensity resistance training groups (both, p 0,01). Changes in body composition, an increase in the proportion of muscle fibers I and IIa and a decrease in the proportion of muscle fibers IIx, an increase in the activity of glucose transporters, and a decrease in systemic inflammation are the main potential mechanisms for the beneficial effects of resistance training, including in combination with blood flow restriction, on insulin resistance in men with metabolic syndrome. Conclusion. There is an inverse relationship between muscle strength and triglycerides/glucose index; resistance training is an effective and safe tool for reducing alternative indicators of insulin resistance and can be included in comprehensive correction programs for men with metabolic syndrome.

IntroductionA 91-year-old sedentary man presenting exhaustion, lower-limb weakness, hypertension, and history of multiple falls was diagnosed with sarcopenia – appendicular skeletal muscle mass index (ASM) of 7.10 kg/m2.PurposeTo investigate the effects of strength training performed with low intensity in isolation (LI) or with blood flow restriction (LI-BFR) on strength, muscle mass, IGF-1, endothelial function, microcirculation, inflammatory biomarkers, and oxidative stress.MethodsIn the first 3 months, LI was performed with intensity corresponding to 30% of 1 repetition maximum, followed by 1 month of inactivity, and another 3 months of LI-BFR (similar load than LI concomitant to BFR equivalent to 50% of resting systolic blood pressure).ResultsLI-BFR, but not LI improved muscle mass, ASM, handgrip strength, isokinetic peak torque, IL-6, and IGF-1. Endothelial function, red blood cell velocity, and concentrations of C-reactive protein, and soluble intercellular adhesion molecules-1 improved after both LI and LI-BFR. Endothelin-1 and oxidative stress increased after LI-BFR, and lowered after LI.ConclusionLI-BFR, but not LI improved strength, muscle mass, IGF-1, endothelial function, and selected inflammatory markers in a nonagenarian sarcopenic patient. These results are promising and suggest that LI-BFR should be considered as an alternative to prevent muscle loss and improve functional fitness in frail older populations.

The aim of this study was to evaluate the impact of high-intensity strength training (ST) or low-intensity strength training with blood flow restriction (ST-BFR) on monocyte subsets, the expression of C-C chemokine receptor 5 (CCR5), and CD16 on monocytes, and tumor necrosis factor alpha (TNF-α) production of overweight men. Thirty overweight men were randomly assigned to conventional ST or ST-BFR. Both groups performed exercises of knee extension and biceps curl with equal volume (3 sessions/week) over 8 weeks, and the peripheral frequency of monocytes (CD14+CD16-, classical monocytes; CD14+CD16+, intermediate monocytes; CD14-CD16+, nonclassical monocytes), the mean fluorescence intensity (MFI) of CCR5 and CD16 on CD14+ monocytes; and the production of TNF-α by lipopolysaccharide (LPS)-stimulated cells were quantified. Eight weeks of ST increased the frequency of CD14+CD16- monocytes (p = 0.04) and reduced the percentage of CD14-CD16+ (p = 0.02) and the production of TNF-α by LPS-stimulated cells (p = 0.03). The MFI of CD16 on CD14+ monocytes decreased after the ST intervention (p = 0.02). No difference in monocyte subsets, CCR5 or CD16 expression, and TNF-α production were identified after ST-BFR intervention (p > 0.05). The adoption of ST promotes anti-inflammatory effects on monocyte subsets of overweight men, but this effect was lost when BFR was adopted. Novelty High-intensity strength training reduces the production of TNF-α and the peripheral frequency of CD16+ monocytes in overweight men. Blood flow restriction method blunts the strength training adaptations on monocyte subsets and pro-inflammatory TNF-α production in overweight men.

Differences in muscle strength adaptations between high-load (HL) and low-load blood flow restricted (BFR) resistance training protocols may be due to the type of strength test performed (e.g isotonic, isokinetic and isometric). PURPOSE: To assess differences in isotonic, isometric and isokinetic strength adaptations in older adults following HL and BFR resistance training. METHODS: Thirty-six males and females (mean: 75.6+7.6 years, 1.67+.09 m, 74.3+13.2 kg) classified as being at risk of mobility limitations were randomly assigned to HL (70% 1-RM) or low-load BFR (30% 1-RM coupled with a vascular restriction) exercise for the knee extensors twice per week for 6 weeks. A control group performed light upper body resistance and flexibility training. Knee extension 10-RM to predict 1-RM strength, isometric maximum voluntary contraction (MVC) and isokinetic strength at 60[BULLET OPERATOR]s-1, 180[BULLET OPERATOR]s-1, and 300[BULLET OPERATOR]s-1were measured before and after 6-weeks of training. RESULTS: HL and BFR training increased predicted 1-RM strength 34% (P<.001) and 24% (P<.001) respectively, from baseline to 6-weeks of training. HL training produced a 16% increase in MVC (P=.002) while BFR training did not change (P=.91). No interventions, included the control, resulted in changes in isokinetic strength at the various speeds (P>.20). CONCLUSION: Strength improvements from HL resistance training carried over to other strength tests. This favorable adaptation did not occur following BFR exercise which may limit the effectiveness of this training program. Isotonic training does not carry over to isokinetic strength adaptations and therefore may be a drawback when implementing resistance training programs for older adults. Supported by NIH grant 1R15 A6040700-01A1.

Background: Osteoarthritis (OA) is the third leading cause of disability worldwide, significantly impacting pain, physical function, and quality of life (QoL). Among its types, knee osteoarthritis (KOA) is the most prevalent, affecting over 80% of individuals with OA. Effective conservative management is crucial for mitigating its physical and social burden. Exercise therapy, including strength training, has been widely utilized; however, the comparative efficacy of blood flow restriction training (BFRT) and traditional strength training remains underexplored. Objective: This study aimed to compare the impact of BFRT and traditional strength training on pain and QoL in patients with KOA. Methods: This randomized controlled trial was conducted between March 2024 and August 2024, enrolling 38 patients with KOA using a purposive sampling technique. Participants aged 40–70 years with clinically and radiologically confirmed KOA experiencing moderate-to-severe symptoms were included. Patients with contraindications to BFRT, such as vascular disorders or recent surgeries, were excluded. The interventions included BFRT with low-load resistance and traditional high-load strength training. Pain and QoL were assessed using the Visual Analogue Scale (VAS) and the Knee Injury and Osteoarthritis Outcome Score (KOOS), respectively. Ethical considerations were followed throughout the study, and SPSS version 24 was used for statistical analysis. Results: Baseline VAS scores were 7.4 ± 1.1 for the BFRT group and 7.3 ± 1.2 for the traditional group (p = 0.87). Post-intervention, VAS improved significantly in both groups, with BFRT showing a greater reduction (3.2 ± 1.0) compared to the traditional group (4.5 ± 1.1, p = 0.01). KOOS scores improved from 48.6 ± 6.9 to 72.3 ± 7.5 in the BFRT group and from 47.9 ± 7.2 to 64.7 ± 8.1 in the traditional group (p = 0.03). Both groups demonstrated significant improvements, with BFRT showing superior results. Conclusion: Both BFRT and traditional strength training significantly improved pain and QoL in KOA patients, with BFRT yielding more pronounced benefits. BFRT offers a promising low-load alternative for managing pain and enhancing QoL in individuals with KOA.

Pain is a common symptom among individuals living with multiple sclerosis (MS). Exercise-induced hypoalgesia (EIH), a reduction in pain sensitivity following resistance exercise, typically requires high loads. Blood flow restriction (BFR) training may offer a lower-load alternative to elicit EIH. This investigation aimed to assess EIH responses following resistance exercise with and without BFR in individuals with MS. 15 participants diagnosed with MS completed three exercise sessions consisting of isotonic, unilateral leg extensions with the current exercise recommendation (high-load, 70% of 1RM), low-load BFR (LL + BFR, 30% of 1RM with BFR), or low-loads (30% of 1RM without BFR). Pain pressure threshold ("uncomfortable") and tolerance ("painful") of the rectus femoris were assessed before and after each exercise session. After each exercise set, participants rated their pain (0-10) which was used for mediation analyses. Participants completed similar exercise volume (high-load = 3056.0 ± 728.2kg; low-load = 3208.3 ± 1041.5kg) but pain pressure threshold was greater (p = 0.012-0.025) following LL + BFR (1.04 ± 0.97 Δkgf) compared to high-load (0.37 ± 0.70 Δkgf) and low-load exercise (0.28 ± 0.69 Δkgf). Pain pressure tolerance was greater (p = 0.015) following LL + BFR (1.41 ± 1.01 Δkgf) compared to low-load exercise (0.23 ± 1.69 Δkgf). Peak pain was greater (p = 0.004-0.030) during LL + BFR (4.3 ± 2.9 au) compared to high-load (1.6 ± 1.7 au) and low-load (2.3 ± 2.4 au) exercise but was not a significant mediator of the EIH response. LL + BFR elicited a local EIH response compared to the current exercise recommendation (high-load) and low-load resistance exercise. These findings suggest that LL + BFR may be an potent exercise intervention to acutely alter pain sensitivity in patients with MS.

Blood flow restriction (BFR) therapy is a technique that uses partial occlusion of arterial blood flow in tandem with low-load resistance training to promote an environment of metabolic stress within muscle tissue. It is hypothesized that such therapy can facilitate protein synthesis and muscle hypertrophy even in the setting of age, injury, or postoperative rehabilitation-conditions which are marred by muscle atrophy and progressive loss of function. Therefore, BFR may be a successful option to facilitate strength gains even in patients unable to perform traditional high-load resistance training. BFR therapy has been shown to be efficacious when used in healthy athletes, the elderly, or in postoperative patients undergoing rehabilitation after upper or lower extremity procedures. More specifically, BFR application in patients undergoing knee surgery has been shown to reduce muscle atrophy post operatively. BFR involves application of a tourniquet or occlusion cuff at 70% of the determined arterial occlusion pressure (commonly 150-180 mm Hg). The arterial occlusion pressure is calculated by observing the loss of Doppler ultrasonography signal at the pedal pulses with sequential inflation of a blood pressure cuff. This cuff should be applied as proximal as possible at the affected extremity. The patient subsequently performs 5 exercises, including 3 sets of 15 repetitions of each exercise, with 30 seconds of rest in between sets. The cuff remains inflated for all 5 exercises. BFR in tandem with low-load resistance training has been shown to be effective in improving lower extremity muscle torque and mass of the quadriceps and hamstring muscles when used after knee surgery, specifically anterior cruciate ligament (ACL) reconstruction. The most commonly reported adverse outcomes after BFR include muscle soreness and sensory paresthesias; however, BFR is generally believed to be safe and acceptable for use in a broad spectrum of patients. Muscle atrophy and loss of strength are hallmarks of aging, injured, and postoperative patients. Traditional means of high-intensity strength training is not feasible in these patient populations, and the use of BFR in tandem with lower intensity strength training shows promise in its ability to promote improvements in muscle strength and hypertrophy. However, more high-level research into the long-term effects, complications, and optimal BFR training regimen is warranted. The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Introduction: Cytokines are a group of proteins essential for inflammatory responses to pathological stimuli such as inflammation and for improving metabolic health in overweight individuals. The purpose of this research was to determine the effect of two types of resistance training with and without blood flow restriction on some pro-inflammatory cytokines in overweight men. Methods: The present study was a semi-experimental interventional study. Fifty males with a mean age of 25.66±1.98 years and a body mass index of 28.1±3.34 kg/m2 were selected and randomly divided into 5 groups: resistance training 1 (n=10), resistance training 2 (n=10), resistance training 1 with blood flow restriction (n=10), resistance training 2 with blood flow restriction (n=10), and control groups (n=10). Resistance training 1 and 2, both with and without flow restriction, were performed for 6 weeks, 3 sessions per week. Before and after six weeks of training, blood samples were collected from the participants and serum levels of TNF-a, IL-1 β, and IL-6 were measured using ELISA. Subsequently, between-group changes were evaluated using the covariance test and within-group Bonferroni test. Results: The results showed a significant difference among the 5 research groups regarding TNF-α and IL-6 levels (P=0.000), and the changes in TNF-α levels in resistance training groups 1 (P=0.003), resistance training 2 (P=0.004), resistance training 1 and 2 with blood flow restriction (P=0.000) were significantly reduced compared to the control group. Additionally, the changes in IL-6 levels in resistance training groups 1 and 2 utilizing flow restriction were also significantly reduced compared to the control group (P=0.001), while no significant difference was observed between the research groups in IL-1 β levels. Conclusion: Our study shows that resistance training with and without blood flow restriction can be a useful non-pharmacological tool to reduce some chronic inflammatory factors.

Introduction Low-load Blood Flow Restriction training (BFRT) is a viable alternative to high-load resistance training (HLT), especially for clinical populations, due to its lower mechanical tension (Centner et al., 2019). Despite using lower loads, BFRT achieves comparable or slightly lower gains in muscle hypertrophy and strength than HLT. However, neural adaptations after low-load BFRT remain poorly understood and are hypothesized to be less pronounced (Centner &amp; Lauber, 2020). Thus, this study aimed to compare the effects of BFRT and HLT, as well as the sequential application of HLT following BFRT, to address potential gaps in neuromuscular adaptation (Duchateau et al., 2021). Methods In this 10-week randomized controlled trial, 37 healthy male and female adults (35-60 years) completed progressive resistance training for knee extensors either 8 weeks with low-load BFRT followed by 2 weeks of HLT, or exclusively HLT. Measurements at baseline including familiarization (PRE1 and PRE2), 8 weeks (MID) and 10 weeks (POST) included maximal voluntary contraction of knee extensors (MVC), leg press strength (LP), voluntary activation (VA, via electrical muscle stimulation) and vastus lateralis muscle volume (V_VL, via ultrasound at 30-70% femur length). Linear mixed models were used to analyze group differences over time, with Cohen’s d effect sizes. Here, we report the preliminary data of 20 participants. Results Reliability between PRE1 and PRE2 was excellent for MVC and V_VL (ICC&gt;0.98) and good for LP (ICC=0.88). From PRE2 to POST, MVC showed a moderate overall increase (+14.7%, d=0.49), while from MID to POST the BFRT group benefited slightly more (d=-0.14). LP increased similarly in both groups at MID (+5.9), but at POST, the HLT group demonstrated a greater increase compared to the BFRT group (+14.8%, d=0.32). No meaningful differences in VA changes were observed between groups or across timepoint, however, the interaction at POST favored more change in BFRT compared to HLT (d=-0.3). Both groups showed comparable increases in V_VL, with negligible differences between groups (+3.4%, d=0.05). Discussion/Conclusion The results of the analyzed sub-sample imply that BFRT and HLT lead to similar changes in maximal force, neural adaptation, and muscle size, however, a large variability was found. The greater increase in VA and MVC in the BFRT group at POST suggests that sequential HLT training after BFRT may enhance performance more than HLT alone (Duchateau et al., 2021). The analysis of the remaining participants may help clarify these effects and enlighten, how mechanical tension and metabolic stress contribute to neural adaptations.

Jones, MJ, Dominguez, JF, Macatugal, C, Coleman, K, Reed, B, and Schroeder, ET. Low load with BFR vs. high load without BFR eccentric hamstring training have similar outcomes on muscle adaptation. J Strength Cond Res 37(1): 55-61, 2023-A key principle of hamstring injury rehabilitation is developing high eccentric force capability through resistance training (RT). However, it can take months before high-load RT is deemed safe and appropriate for rehabilitating serious hamstring injuries. Low-load blood flow restriction (BFR) RT has been identified as an effective alternative when high-load RT is contraindicated but has been scarcely investigated in the hamstring. To address this gap in knowledge, we sought to compare the effect of longitudinal BFR RT with traditional RT on eccentric hamstring power, strength, lean mass, perceived soreness, and acute muscle swell in healthy adults (n = 40; 19 F, 21 M; mean ± SD; age: 24.3 ± 2.6 years). Our crossover design compared the effects of low-load (30% 1RM) eccentric lower extremity training with BFR (BFR-ELET) with traditional high-load (80% 1RM) eccentric lower extremity training (TRAD-ELET) without BFR biweekly for 6 weeks. Outcomes were tested pre/post-intervention with significance at α = 0.05. Both interventions yielded dependent variable outcomes that did not differ significantly except for muscle swell assessed by bioelectrical impedance analysis, which decreased significantly more in the BFR-ELET condition compared with TRAD-ELET (mean ± SD: -0.32 ± 0.02, Φ° 50 kHz), CI: -0.35 to -0.28, Φ° 50 kHz, p < 0.001, Cohen's d = 2.95). Our findings support BFT-ELET as an effective alternative to TRAD-ELET for enhancing strength and identify myocellular swelling as a potential mediator for strength outcomes associated with BFR training.

Muscle damage affects the blood leukocyte profile. Resistance exercise (RE) with blood flow restriction (BFR) attenuates exercise-induced muscle damage (EIMD).PurposeTo evaluate muscle damage and the leukocyte profile in response to RE+BFR and to compare with high intensity RE.MethodsTwenty volunteers performed the RE in the leg press apparatus in the following groups: RE80, 80% of 1RM (3 × until concentric muscle failure); RE40+BFR, 40% of 1RM with BFR (same total work of RE80 group). The BFR applied was 80% of the total occlusion pressure.ResultsThere were no differences in the blood leukocyte profile among groups despite the lower exercise-induced muscle damage (EIMD) in the RE40+BFR group (RE80: 10.07 ± 2.67 vs. RE40+BFR: 8.25 ± 0.96; cell × 103/mm3). Both groups showed leukocytosis (RE80: 7.59 ± 1.48 vs. 10.07 ± 2.67 and RE40+BFR: 6.57 ± 1.50 vs. 8.25 ± 0.96; cell × 103/mm3) and lymphocytosis (RE80: 2.48 ± 0.83 vs. 3.65 ± 1.31 and RE40+BFR: 2.22 ± 0.23 vs. 3.03 ± 0.65; cell × 103/mm3) immediately after exercise. Leukocytosis (ES 1.12 vs. ES 1.33) and lymphocytosis (ES 1.11 vs. ES 1.76) was greater in the RE40+BFR group.ConclusionRE associated with BFR was accompanied by a greater leukocytosis and lymphocytosis immediately after exercise, with no difference in neutrophils. This leukocyte blood profile may be related to less muscle damage, as well as faster muscle recovery after 24 and 48 h post-exercise.

This study compared the acute effects of low-intensity resistance exercise (RE) sessions for the upper limb with continuous and intermittent blood flow restriction (BFR) and high-intensity RE with no BFR on lactate, heart rate, double product (DP; heart rate times systolic blood pressure), and perceived exertion (RPE). Ten recreationally trained men (1-5 years strength training; age mean = 19 ± 0.82 years) performed three experimental protocols in random order: (a) low-intensity RE at 20% one-repetition maximum (1RM) with intermittent BFR (LI + IBFR), (b) low-intensity RE at 20% 1RM with continuous BFR (LI + CBFR), and (c) high-intensity RE at 80% 1RM. The three RE protocols increased lactate and DP at the end of the session ( p < .05) and increased heart rate at the end of each exercise ( p < .05). However, greater local and general RPE was observed in the high-intensity protocol compared with LI + IBFR and LI + CBFR in the lat pull-down, triceps curl, and biceps curl exercises ( p < .05). A greater percentage change in DP and lactate was observed for continuous BFR compared with intermittent BFR; however, RPE was lower for intermittent BFR. In conclusion, intermittent BFR appears to be an excellent option for physical training because it did not differ significantly from continuous BFR in any variable and promoted a lower percentage change in DP and RPE.

Low volume blood flow restricted (BFR) training has been proposed to induce comparable adaptations to traditional resistance training, however the underlying mechanisms remain unknown. Despite the absence of direct support, a suggested mechanism of BFR is an increase in reactive oxygen species (ROS). PURPOSE: We aimed to determine if the rate of mitochondrial ROS emission was altered following an acute bout of occluded (BFR) or non-occluded resistance training (RT), and to mechanistically investigate the role of skeletal muscle O2 partial pressure (pO2) in this response. METHODS: Ten males (25±1yrs) performed 3 sets of single leg squats to failure at 30% 1RM, with either BFR (60-70% occlusion), or without occlusion (RT), while skeletal muscle tissue oxygenation was estimated using near-infrared spectroscopy. Muscle biopsies were obtained at rest and 2-hours post-exercise to determine mitochondrial respiration and ROS emission in permeabilized muscle fibers. In a separate cohort, muscle biopsies were obtained from six males (25±2yrs) to examine the effects of pO2 on in vitro mitochondrial bioenergetics. RESULTS: Resistance exercise, with or without BFR, did not alter maximal respiratory capacity or mitochondrial sensitivity to ADP. While maximal mitochondrial ROS emission was unchanged following RT, BFR decreased this response compared to rest (66.6 vs. 86.2 pmol min-1 mg dry wt-1, p<0.05). Skeletal muscle oxygenation was lower in the BFR compared to RT leg, both during (41.4% vs. 46.1% saturation respectively, p<0.01) and between (50.3% vs. 61.1% saturation respectively, p<0.01) exercise sets. Further evaluation of mitochondrial bioenergetics in vitro revealed that mild O2 restriction (50μM) dramatically attenuated maximal mitochondrial ROS emission (~4-fold), and fraction electron leak to ROS (~3-fold) compared to room air (200μM). This effect was especially evident in the presence of non-saturating ADP, as submaximal ROS emission was almost completely suppressed during O2 restriction, without a reduction in submaximal respiration. CONCLUSIONS: These data indicate that a reduction in skeletal muscle pO2 attenuates the propensity of mitochondria to produce ROS, a mechanism which may contribute to the acute responses to BFR training. This research is supported by NSERC funding.

ABSTRACTObjective: To determine the effect of blood flow restriction (BFR) applied to the legs at different pressures (40% and 60%) on intraocular pressure (IOP) during the execution of ten repetitions maximum (10RM) in the half-squat exercise. Methods: Quasi-experimental, prospective study with 17 healthy physically active subjects (9 males and 8 females; 24.1 ± 4.2 years). Two sessions were conducted. The 10RM load was determined in the first session. The second session consisted of 10RM under three BFR conditions (no-BFR, 40%-BFR, and 60%-BFR) that were applied in random order. IOP was measured before each condition, immediately after each repetition, and after 1 minute of passive recovery. A two-way repeated-measures ANOVA (restriction type [no-BFR, 40%-BFR, and 60%-BFR] x measurement point [basal, repetitions 1–10, and recovery]) was applied on the IOP measurements. Results: A significant main effect of the BFR condition (p = .022, ƞp2 = 0.21) was observed due to the significantly higher mean IOP values for the 60%-BFR (19.0 ± 0.7 mmHg) compared to the no-BFR (18.0 ± 0.8 mmHg; p = .048, dunb = 1.30). Non-significant differences with a large effect size were reached between 60%-BFR and 40%-BFR (18.1 ± 0.8 mmHg; p = .081, dunb = 1.16) and between no-BFR and 40%-BFR (p = .686, dunb = 0.18). IOP increased approximately 3–4 mmHg from baseline to the last repetition. Conclusions: Low-pressure BFR (40%-BFR) in combination with moderate-load (10RM load) resistance exercise could be an effective and safe strength training strategy while avoiding IOP peaks associated with heavy-load resistance exercises. These findings incorporate novel insights into the most effective exercise strategies in individuals who need to maintain stable IOP levels (e.g., glaucoma patients).

Synopsis Restoration of skeletal muscle mass and strength is critical to successful outcomes following orthopaedic surgery. Blood flow restriction (BFR) resistance exercise has emerged as a promising means of augmenting traditional low-intensity physical rehabilitation exercise and has yielded successful outcomes in a wide range of applications. Though BFR is well tolerated and safe for most individuals, patients who have undergone orthopaedic surgery may be an exception, due to their heightened risk for venous thromboembolism (VTE). While the pathogenesis of VTE is multifactorial and specific to the individual, it is commonly described as a combination of blood stasis, endothelial injury, and alterations in the constituents of the blood leading to hypercoagulability. The collective literature suggests that, given the pathogenic mechanisms of VTE, limited use of a wide, partially occluding cuff during resistance exercise should be low risk, and the likelihood that BFR would directly cause a VTE event is remote. Alternatively, it is plausible that BFR may enhance blood flow and promote fibrinolysis. Of greater concern is the individual with pre-existing asymptomatic VTE, which could be dislodged during BFR. However, it is unknown whether the direct risk associated with BFR is greater than the risk accompanying traditional exercise alone. Presently, there are no universally agreed-upon standards indicating which postsurgical orthopaedic patients may perform BFR safely. While excluding all these patients from BFR may be overly cautious, clinicians need to thoroughly screen for VTE signs and symptoms, be cognizant of each patient's risk factors, and use proper equipment and prescription methods prior to initiating BFR. J Orthop Sports Phys Ther 2019;49(1):17-27. Epub 12 Sep 2018. doi:10.2519/jospt.2019.8375.