Effects of Blood Flow Restriction Exercise and Possible Applications in Type 2 Diabetes

Physiological adaptations and performance enhancement with combined blood flow restricted and interval training: A systematic review with meta-analysis

OBJECTIVES

We aimed to determine: (a) the chronic effects of interval training (IT) combined with blood flow restriction (BFR) on physiological adaptations (aerobic/anaerobic capacity and muscle responses) and performance enhancement (endurance and sprints), and (b) the influence of participant characteristics and intervention protocols on these effects.

METHODS

Searches were conducted in PubMed, Web of Science (Core Collection), Cochrane Library (Embase, ClinicalTrials.gov, and International Clinical Trials Registry Platform), and Chinese National Knowledge Infrastructure on April 2, with updates on October 17, 2024. Pooled effects for each outcome were summarized using Hedge's g (g) through meta-analysis-based random effects models, and subgroup and regression analyses were used to explore moderators.

RESULTS

A total of 24 studies with 621 participants were included. IT combined with BFR (IT+BFR) significantly improved maximal oxygen uptake (VO2max) (g = 0.63, I2 = 63%), mean power during the Wingate 30-s test (g = 0.70, I2 = 47%), muscle strength (g = 0.88, I2 = 64%), muscle endurance (g = 0.43, I2 = 0%), time to fatigue (g = 1.26, I2 = 86%), and maximal aerobic speed (g = 0.74, I2 = 0%) compared to IT alone. Subgroup analysis indicated that participant characteristics including training status, IT intensity, and IT modes significantly moderated VO2max (subgroup differences: p < 0.05). Specifically, IT+BFR showed significantly superior improvements in VO2max compared to IT alone in trained individuals (g = 0.76) at supra-maximal intensity (g = 1.29) and moderate intensity (g = 1.08) as well as in walking (g = 1.64) and running (g = 0.63) modes. Meta-regression analysis showed cuff width (β = 0.14) was significantly associated with VO2max change, identifying 8.23 cm as the minimum threshold required for significant improvement. Subgroup analyses regarding muscle strength did not reveal any significant moderators.

CONCLUSION

IT+BFR enhances physiological adaptations and optimizes aspects of endurance performance, with moderators including training status, IT protocol (intensity, mode, and type), and cuff width. This intervention addresses various IT-related challenges and provides tailored protocols and benefits for diverse populations.

How can Blood Flow Restriction Exercise be Utilised for the Management of Persistent Pain Following Complex Injuries in Military Personnel? A Narrative Review

BACKGROUND

Persistent pain is a complicated phenomenon associated with a wide array of complex pathologies and conditions (e.g., complex regional pain syndrome, non-freezing cold injury), leading to extensive disability and reduced physical function. Conventional resistance training is commonly contraindicated in load compromised and/or persistent pain populations, compromising rehabilitation progression and potentially leading to extensive pharmacological intervention, invasive procedures, and reduced occupational status. The management of persistent pain and utility of adjunct therapies has become a clinical and research priority within numerous healthcare settings, including defence medical services.

MAIN BODY

Blood flow restriction (BFR) exercise has demonstrated beneficial morphological and physiological adaptions in load-compromised populations, as well as being able to elicit acute hypoalgesia. The aims of this narrative review are to: (1) explore the use of BFR exercise to elicit hypoalgesia; (2) briefly review the mechanisms of BFR-induced hypoalgesia; (3) discuss potential implications and applications of BFR during the rehabilitation of complex conditions where persistent pain is the primary limiting factor to progress, within defence rehabilitation healthcare settings. The review found BFR application is a feasible intervention across numerous load-compromised clinical populations (e.g., post-surgical, post-traumatic osteoarthritis), and there is mechanistic rationale for use in persistent pain pathologies. Utilisation may also be pleiotropic in nature by ameliorating pathological changes while also modulating pain response. Numerous application methods (e.g., with aerobic exercise, passive application, or resistance training) allow practitioners to cater for specific limitations (e.g., passive, or contralateral application with kinesiophobia) in clinical populations. Additionally, the low-mechanical load nature of BFR exercise may allow for high-frequency use within residential military rehabilitation, providing a platform for conventional resistance training thereafter.

CONCLUSION

Future research needs to examine the differences in pain modulation between persistent pain and pain-free populations with BFR application, supporting the investigation of mechanisms for BFR-induced hypoalgesia, the dose-response relationship between BFR-exercise and pain modulation, and the efficacy and effectiveness of BFR application in complex musculoskeletal and persistent pain populations.

A novel glycopeptide from mountain-cultivated ginseng residue protects type 2 diabetic symptoms-induced heart failure

ETHNOPHARMACOLOGICAL RELEVANCE

Mountain-cultivated Panax ginseng C.A.Mey. (MCG) with high market price and various properties was valuable special local product in Northeast of Asia. MCG has been historically used to mitigate heart failure (HF) for thousand years, HF is a clinical manifestation of deficiency of "heart-qi" in traditional Chinese medicine. However, there was little report focus on the activities of extracted residue of MCG.

AIM OF THE STUDY

A novel glycopeptide (APMCG-1) was isolated from step ethanol precipitations of alkaline protease-assisted extract from MCG residue.

MATERIALS AND METHODS

The molecular weight and subunit structure of APMCG-1 were determined by FT-IR, HPLC and GPC technologies, as well as the H9c2 cells, Tg (kdrl:EGFP) zebrafish were performed to evaluated the protective effect of APMCG-1.

RESULTS

APMCG-1 was identified as a glycopeptide containing seven monosaccharides and seven amino acids via O-lined bonds. Further, in vitro, APMCG-1 significantly decreased reactive oxygen species production and lactate dehydrogenase contents in palmitic acid (PA)-induced H9c2 cells. APMCG-1 also attenuated endoplasmic reticulum stress and mitochondria-mediated apoptosis in H9c2 cells via the PI3K/AKT signaling pathway. More importantly, APMCG-1 reduced the blood glucose, lipid contents, the levels of heart injury, oxidative stress and inflammation of 5 days post fertilization Tg (kdrl:EGFP) zebrafish with type 2 diabetic symptoms in vivo.

CONCLUSIONS

APMCG-1 protects PA-induced H9c2 cells while reducing cardiac dysfunction in zebrafish with type 2 diabetic symptoms. The present study provides a new insight into the development of natural glycopeptides as heart-related drug therapies.

The effect of blood flow-restrictive resistance training on the risk of atherosclerotic cardiovascular disease in middle-aged patients with type 2 diabetes: a randomized controlled trial

Introduction

The aim of this study was to investigate the effects of blood flow-restrictive resistance training (BFR-RT) on improving metabolic abnormalities, blood pressure (BP), obesity, and 10-year atherosclerotic cardiovascular disease (ASCVD) risk in middle-aged patients with type 2 diabetes mellitus (T2DM).

Method

We conducted a parallel-group, single blind randomized controlled trial. Participants who met the inclusion criteria were randomly divided into control group, BFR-RT group and aerobic exercise (AE) group. Control group received health education and follow-up; Two exercise groups received supervised collective training for a period of six months, three times per week. AE group trained at moderate-intensity for 60 minutes each time, while BFR-RT group trained at low-intensity for 40 minutes each time. The primary outcomes were change in 10-year ASCVD risk index and level, and the secondary outcomes included changes in fasting plasma glucose (FPG), glycosylated hemoglobin (HbA1c), blood lipids, BP, and obesity level within and across the three groups at baseline, the third and sixth months of intervention.

Result

Among 93 individuals (control group, n=31; AE, n=30; BFR-RT, n=32) were analyzed. At baseline, there were no significant differences in various indicators among the three groups (p>0.05). After intervention, the 10-year ASCVD risk index and risk level of both exercise groups significantly decreased compared to the control group and baseline (p<0.05), and the risk reduction became more pronounced over time. In the sixth month of intervention, the 10-year ASCVD risk index in the AE group decreased by 27.40%, and that in the BFR-RT group decreased by 26.78%. Meanwhile, apart from lipoprotein (a) and diastolic blood pressure, both exercise groups showed significant improvements in FPG, HbA1c, dyslipidemia, systolic blood pressure, and obesity indicators compared to the control group and baseline (p<0.05). There was no significant difference in various indicators between the two exercise groups (p>0.05).

Conclusion

BFR-RT could reduce the 10-year ASCVD risk in middle-aged T2DM patients for by improving metabolic abnormalities, BP and obesity, and its effect was similar to that of moderate-intensity AE.

Clinical trial registration

https://www.chictr.org.cn/showproj.html?proj=178886, identifier ChiCTR2300074357.

Effect of 6-week BFRT combined with IASTAM therapy on international standard dancers with chronic ankle instability

Background

In sports dance events, athletes often face the risk of ankle injury and instability, which may have a negative impact on their training and athletic performance, and even hinder their rehabilitation process and increase the likelihood of re-injury.

Objective

This study aims to observe the effects of exercise intervention (low-load ankle muscle strength training with blood flow restriction training (BFRT) equipment and balance training with blood flow restriction training equipment) combined with instrumentation therapy (Instrument-assisted soft tissue mobilization, IASTM) on ankle function, joint range of motion, and strength in sports dancers with chronic ankle instability (CAI). This study aims to provide an evidence-based approach to rehabilitation for athletes by comparing the effects of combination therapy approaches to traditional ankle strength and stability training.

Methods

Forty-two subjects with ankle instability, restriction, or discomfort were selected as observation objects and randomly divided into three groups: the combined group (n = 14, blood flow restriction training combined with IASTM), the simple blood flow restriction training group (n = 15), and the conventional ankle strength and stability training group (n = 13). The intervention lasted for 6 weeks, once a week. The three groups were assessed with the Cumberland ankle instability assessment, Foot and Ankle Ability Measure (FAAM) ankle function assessment score, and ankle range of motion measurement before intervention, after the first intervention, and after 6 weeks of intervention. The ankle strength test was compared and analyzed only before and after intervention.

Result

There was no significant difference in the participant characteristics of the three intervention groups. In terms of Cumberland Ankle Instability Tool (CAIT) scores, within-group comparisons showed that the scores after the first intervention and at the 6-week mark were significantly higher than before the intervention (P < 0.05). Between-group comparisons revealed that the combined intervention group had higher CAIT scores than the other two groups after the 6-week intervention. Regarding the FAAM functional scores, all three interventions significantly improved ankle joint function in patients with chronic ankle instability (P < 0.05), with the BFRT group showing significantly higher FAAM - Activities of Daily Living scale (FAAM-ADL) scores than the control group (P < 0.05). Both the combined and BFRT groups also had significantly higher FAAM-SPORT scores after the first intervention compared to the control (P < 0.05). In terms of ankle range of motion improvement, the combined intervention group showed a significant increase in ankle joint motion after the intervention (P < 0.05), particularly in the improvement of dorsiflexion ability (P < 0.05). As for ankle strength enhancement, all three intervention groups experienced an increase in ankle strength after the intervention (P < 0.05), with the combined intervention group showing a significant improvement in both dorsiflexion and inversion strength compared to the control group (P < 0.05).

Conclusion

BFRT combined with IASTM, isolated BFRT, and conventional ankle strength and stability training significantly improve stability, functionality, and strength in CAI patients. The combined intervention demonstrates superior efficacy in improving ankle range of motion compared to isolated BFRT and conventional approaches.

Acute effects of blood flow restricted aerobic exercise in type 2 diabetes mellitus

BACKGROUND

This study aimed to compare the acute effects of aerobic exercise performed with blood flow restriction (BFR), a novel method to increase exercise gains, with blood free flow (BFF) conditions in type 2 diabetes mellitus (T2DM).

METHODS

Fifteen individuals with T2DM performed BFF and BFR (40% of arterial occlusion pressure) cycling exercises 48 hours apart, at equal intensity (45% heart rate reserve) and duration (38 minutes). Systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), blood glucose, heart rate, and muscle oxygen saturation (SmO2) were assessed before-after and during exercise sessions.

RESULTS

SBP, DBP, and MAP in the overload phase were higher in the BFR group than in the BFF group (P = .009, 0.031, and 0.013, respectively). Changes in blood pressure (∆SBP and ∆DBP) were similar between the BFF and BFR groups (P > .05), whereas ∆MAP differed (P = .016). Changes in blood glucose levels and heart rates were not significantly different between the groups. Although SmO2baseline was lower in the BFR group (P = .049), SmO2min and SmO2max did not differ significantly between the BFF and BFR groups.

CONCLUSION

The similar decrease in blood glucose levels between the groups suggests that BFR exercise is favorable in terms of hypoglycemia. The higher blood pressure observed during the BFR exercise remained within safe limits. These results suggest that people with T2DM can safely perform BFR aerobic exercises; however, further studies are required.

The effect of low-intensity suspension training with blood flow restriction on GH, IGF-1, and their association with physical fitness in young women

Blood flow restriction (BFR) has been incorporated in resistance training for over 20 years. We aimed to investigate the impact of low-intensity suspension training with BFR (LIST+BFR) on GH, IGF-1, and their association with physical fitness in young women. Thirty-six active women participated and were randomly assigned to either the high-intensity suspension training (HIST), LIST+BFR, or control (CON) groups. Training groups exercised three sessions weekly for 8 weeks. The CON only engaged in regular physical activity. Fasting serum hormones and physical fitness were assessed 48 h before and after the training intervention. GH and IGF-1 levels significantly higher in the LIST+BFR compared to the HIST and CON. These hormones were significantly higher by HIST, compared to CON. LIST+BFR led to significant enhancements in muscular strength and endurance compared to HIST and CON. Additionally, HIST significantly higher than compared to CON. Sprinting and agility time lower in both suspension training groups rather than the CON. No significant between-groups differences were found in weight. There was a large or moderate correlation between GH and IGF-1 and muscular strength, endurance, sprint, and agility performance. LIST+BFR could more enhanced GH, IGF-1, and muscular strength and endurance in females than HIST.

Lower limb blood flow occlusion increases systemic pressor response without increasing brachial arterial blood flow redistribution in women

This study was conducted to investigate the systemic hemodynamic and vascular changes in women during and after two commonly used clinical blood flow restriction (BFR) pressures at rest. There are minimal data regarding the independent effects of BFR on hemodynamic and systemic vascular changes due to pressor response, particularly among women. Therefore, this study investigated BFR-induced alterations in pressor response and systemic flow redistribution at rest during two commonly used pressures (50% and 80% limb occlusion pressure [LOP]). Fifteen women (22.1 ± 4.2 years) completed two randomised sessions involving 8-min of bilateral, lower limb restriction at 50% or 80% LOP followed by 8-min of recovery post-deflation. Changes in vascular (arterial diameter [DIA], time-averaged mean velocity [TAMV], volume flow [VF], and area) and hemodynamic (heart rate [HR] and blood pressure) measures over time (pre-, during, post-occlusion) and by session (50% vs. 80% LOP) were tested using repeated measures analysis of variance. Repeated measures correlations (rrm) quantified common intraindividual associations between BFR-induced hemodynamic and vascular responses. HR increased from baseline during 50% LOP and remained elevated during recovery (p < 0.05). HR increased from baseline during 80% LOP, while tibial VF and TAMV decreased (p < 0.03 for all). HR and TAMV values returned to baseline during recovery, while brachial artery VF decreased (p < 0.05). Changes in HR, brachial VF, and brachial TAMV were similar between 50% and 80% LOP (rrm = 0.32-0.70, p < 0.05 for all). At 80% LOP, changes in HR were positively correlated with brachial VF (rrm = 0.38) and TAMV (rrm = 0.43) and negatively correlated with tibial VF (rrm = -0.36) and TAMV (rrm = -0.30) (p < 0.05 for all). Results suggest that BFR at 80% LOP elicits an acute systemic pressor reflex without concomitant increases in brachial arterial flow, while 50% LOP elicits a subdued response.

Effect of blood flow-restrictive resistance training on metabolic disorder and body composition in older adults with type 2 diabetes: a randomized controlled study

Introduction

To explore whether blood flow-restrictive resistance exercise (BFRE) can be used as an alternative strategy to moderate-intensity resistance training (RT) to improve metabolic disorder and body composition in older adults with type 2 diabetes (T2DM).

Methods

This is a single-blind, randomized, controlled trial. Ninety-eight older adults with T2DM were randomly divided into three groups: BFRE group (n = 34), RT group (n = 31) and control group (n = 33). Two exercise groups received supervised collective training for a period of six months, each lasting 50 min, three times a week. The primary outcomes included fasting plasma glucose (FPG), Glycosylated hemoglobin (HbA1c), blood lipids, blood pressure, and body composition. The secondary outcome was muscle performance.

Results

After six months of intervention, the FPG, HbA1c, blood lipids, diastolic blood pressure, body composition, and muscle performance of the two exercise groups were significantly improved relative to the control group and baseline measurements (P < 0.05). There was no significant increase in lean mass between the two exercise groups compared to the control group and baseline (p > 0.05). There was no significant decrease in systolic blood pressure between the two exercise groups compared to the control group (p > 0.05), but it was significantly lower than their baseline (P < 0.05). There was no significant difference in all indicators between the two exercise groups at the baseline, third and sixth months of intervention (p > 0.05).

Discussion

BFRE can safely and effectively improve the metabolic disorder and body composition of older adults with T2DM. For elderly exercise beginners, BFRE can be used as an alternative strategy to moderate-intensity resistance training.

Clinical trial registration

https://www.chictr.org.cn/showproj.html?proj=178886, identifier ChiCTR2300074357.

The effects of extracellular vesicles and their cargo on metabolism and its adaptation to physical exercise in insulin resistance and type 2 diabetes

Lifestyle modification represents the first-line strategy for the prevention and treatment of type 2 diabetes mellitus (T2DM), which is frequently associated with obesity and characterized by defective pancreatic insulin secretion and/or insulin resistance. Exercise training is an essential component of lifestyle modification and has been shown to ameliorate insulin resistance by reducing body fat mass and by enhancing skeletal muscle mitochondrial biogenesis and insulin-independent glucose uptake. Additionally, exercising stimulates the release of exerkines such as metabolites or cytokines, but also long non-coding RNA, microRNAs, cell-free DNA (cf-DNA), and extracellular vesicles (EVs), which contribute to inter-tissue communication. There is emerging evidence that EV number and content are altered in obesity and T2DM and may be involved in several metabolic processes, specifically either worsening or improving insulin resistance. This review summarizes the current knowledge on the metabolic effects of exercise training and on the potential role of humoral factors and EV as new biomarkers for early diagnosis and tailored treatment of T2DM.

Impact of low-load resistance exercise with and without blood flow restriction on muscle strength, endurance, and oxidative capacity: A pilot study

Low-load resistance exercise (LLRE) to failure can increase muscle mass, strength, endurance, and mitochondrial oxidative capacity (OXPHOS). However, the impact of adding blood flow restriction to low-load resistance exercise (LLBFR) when matched for volume on these outcomes is incompletely understood. This pilot study examined the impact of 6 weeks of single-legged LLBFR and volume-matched LLRE on thigh bone-free lean mass, strength, endurance, and mitochondrial OXPHOS. Twenty (12 males and 8 females) untrained young adults (mean ± SD; 21 ± 2 years, 168 ± 11 cm, 68 ± 12 kg) completed 6 weeks of either single-legged LLBFR or volume-matched LLRE. Participants performed four sets of 30, 15, 15, and 15 repetitions at 25% 1-RM of leg press and knee extension with or without BFR three times per week. LLBFR increased knee extension 1-RM, knee extension endurance, and thigh bone-free lean mass relative to control (all p < 0.05). LLRE increased leg press and knee extension 1-RM relative to control (p = 0.012 and p = 0.054, respectively). LLRE also increased mitochondrial OXPHOS (p = 0.047 (nonparametric)). Our study showed that LLBFR increased muscle strength, muscle endurance, and thigh bone-free lean mass in the absence of improvements in mitochondrial OXPHOS. LLRE improved muscle strength and mitochondrial OXPHOS in the absence of improvements in thigh bone-free lean mass or muscle endurance.

Study on the effect of blood flow restriction training combined with IASTAM on ankle strength and function intervention in athletes with chronic ankle instability in sport dance events

BACKGROUND

Athletes engaged in sports dance frequently encounter the potential for ankle injuries and instability, factors that may contribute to diminished training efficacy, compromised athletic performance, prolonged recuperation, and heightened susceptibility to recurring injuries.

OBJECTIVE

The objective of this study was to investigate the impact of an exercise intervention (comprising blood flow restriction training combined with low-load ankle muscle strength training and balance training) as well as instrument-assisted soft tissue mobilization (IASTM) on the foot and ankle function, strength, and range of motion in sports dance athletes exhibiting ankle instability (CAI).

METHODS

Thirty participants exhibiting ankle instability, restriction, or discomfort were recruited and randomly assigned to two groups: the Test group (comprising blood flow restriction training combined with IASTM, n = 15) and the traditional ankle strength training group (n = 15). The intervention spanned 4 weeks, with one session per week. Assessment of the Cumberland Ankle Instability Tool (CAIT), Foot and Ankle Ability Measure (FAAM), and ankle range of motion occurred at three time points: pre-intervention, immediately following the initial intervention, and after 4 weeks of intervention. Ankle strength testing was conducted solely before and after the intervention for comparative analysis.

RESULTS

There were no significant variances in baseline characteristics between the two intervention groups. In terms of CAIT scores, both groups exhibited notably higher scores following the initial intervention and after 4 weeks of intervention compared to pre-intervention (P < 0.05). The Test group displayed higher CAIT scores than the control group, signifying a more pronounced enhancement in ankle stability among patients in the Test group. Concerning FAAM scores, both groups significantly enhanced ankle function in CAI patients (P < 0.05), with the Test group demonstrating notably higher FAAM-SPORT scores than the control group (P < 0.05), indicating superior restoration of athletic capability in the Test group. As for improvements in ankle range of motion, both groups demonstrated significant enhancements compared to pre-intervention (P < 0.05). The Test group exhibited significantly superior improvements in dorsiflexion, eversion, and inversion range of motion compared to the control group (P < 0.05), while the control group did not exhibit significant enhancements in plantarflexion and eversion range of motion (P > 0.05). Both groups displayed enhanced ankle strength in CAI patients following the intervention (P < 0.05), with the Test group manifesting notably higher dorsiflexion and inversion strength than the control group (P < 0.05).

CONCLUSION

Both blood flow restriction training combined with IASTM and traditional ankle strength and stability training have shown significant improvements in stability, function, strength, and range of motion in CAI patients. Furthermore, the Test group exhibits superior efficacy in ankle stability, daily functional movement, dorsiflexion, and eversion range of motion compared to the control group.

CLINICAL TRIAL REGISTRATION

9 February 2024, ClinicalTrials.gov, ID; NCT06251414.

Evaluation of the Effectiveness of In-Hospital Exercise Rehabilitation in Middle-Aged and Elderly Patients with Type 2 Diabetes Mellitus Combined with Sarcopenia Effect of Lifestyle Management on Disease Status in Patients with Type 2 Diabetes Mellitus

OBJECTIVE

The aim of this study was to explore the effects of in-hospital exercise rehabilitation on glucose and lipid metabolism and healthy physical fitness in middle-aged and elderly patients with type 2 diabetes mellitus (T2DM) combined with sarcopenia, and to provide a reference for the effective implementation of exercise rehabilitation for middle-aged and elderly patients with T2DM combined with sarcopenia in healthcare institutions.

METHODS

This study retrospectively included 122 patients with T2DM combined with sarcopenia treated at the General Hospital of Ningxia Medical University from August 2017 to August 2020 and randomly divided into a control group and an experimental group. The control group was given conventional treatment and the experimental group was given exercise rehabilitation in the hospital for 12 weeks to compare the indexes related to glucose and lipid metabolism and healthy fitness in the two groups.

RESULTS

After the intervention, the experimental group showed significant decreases in fasting blood glucose (FBG), glycated hemoglobin (HbA1c), insulin resistance index (HOMA-IR), triglycerides (TG), total cholesterol (TC), low-density cholesterol (LDL-C) and body fat percentage (p < 0.05), while high-density cholesterol (HDL-C), grip strength, lower limb extension, lower limb flexion, peak oxygen uptake were significantly higher (p < 0.05) and were more significant at 12 weeks compared to the 6-week intervention (p < 0.05). However, there were no significant changes in any of the glucose metabolism indicators in the control group before and after the intervention. A two-way repeated measures ANOVA showed that at control baseline levels, HbA1c decreased significantly in the experimental group after both 6 and 12 weeks of intervention compared to the control group (p < 0.05). After 6 weeks of intervention, the experimental group showed a significant decrease in body fat percentage and a significant increase in grip strength. After 12 weeks of intervention, the experimental group showed an increase in glycemic control from 33.3% to 73.3%, a significant decrease in body fat percentage and a significant increase in grip strength, lower limb extension and lower limb flexion strength and peak oxygen uptake.

CONCLUSION

In-hospital exercise rehabilitation can effectively improve the glycemic and lipid profiles of patients with T2DM combined with sarcopenia and enhance their health fitness, with good clinical rehabilitation effects.

Effects of blood flow restriction training on muscle fitness and cardiovascular risk of obese college students

Purpose: The aim of this study was to investigate the effect of blood flow restriction (BFR) combined with low-intensity resistance training (RT) on cardiovascular risk factors in obese individuals. Methods: Twenty-six male obese college students were recruited and randomly assigned to a control group (CON, n = 8), a low-intensity RT group (RT, n = 9), and a combined BFR training and low-intensity RT group (BFRT, n = 9). Results: The subjects in BFRT group showed significant reductions in body fat percentage and waist-to-hip ratio and a significant increase in lean mass and muscle mass; the peak torque, peak power, and endurance ratio of knee extensors and elbow flexors were significantly upregulated; the root mean square (RMS) for the medial femoral muscle, lateral femoral muscle and biceps significantly increased; the diastolic blood pressure (DBP) showed a significant decrease. The BFRT group also showed significant up-regulations in RMS of the difference between the adjacent R-R intervals (RMSSD), high-frequency power (HF) of parasympathetic modulatory capacity, the standard deviation of R-R intervals (SDNN) of overall heart rate variability (HRV) changes and low-frequency power (LF) of predominantly sympathetic activity. In addition, glycated hemoglobin (HbA1C), insulin resistance index (HOMA-IR) and fasting blood glucose (FBG) were all significantly downregulated in BFRT group. In parallel, low-density lipoprotein (LDL-C) significantly reduced while high-density lipoprotein (HDL-C) significantly increased in BFRT group. Conclusion: BFR combined with low-intensity RT training effectively improved body composition index, increased muscle mass, improved neuromuscular activation, enhanced muscle strength and endurance, which in turn improved abnormal glucolipid metabolism and enhanced cardiac autonomic regulation.

Insulin Glargine is More Suitable Than Exenatide in Preventing Muscle Loss in Non-Obese Type 2 Diabetic Patients with NAFLD

AIM

This study investigated the effects of insulin glargine and exenatide on the muscle mass of patients with newly diagnosed type 2 diabetes (T2DM) and nonalcoholic fatty liver disease (NAFLD).

METHODS

We performed a post-hoc analysis of our previously study, a 24-week randomized controlled multicenter clinical trial (ClinicalTrials.gov, NCT02303730). Seventy-six patients were randomly assigned 1:1 to receive insulin glargine or exenatide treatment. The changes in psoas muscle area (PMA) (mm2) were obtained with the cross-sectional Dixonfat magnetic resonance images at the fourth lumber vertebra.

RESULTS

There were no significant differences in age, BMI, gender, and PMA in insulin glargine and exenatide groups at baseline. After treatment, PMA tended to increase by 13.13 (-215.52, 280.80) mm2 in the insulin glargine group and decrease by 149.09 (322.90-56.39) mm2 in the exenatide group (both p>0.05). Subgroup analysis showed a 560.64 (77.88, 1043.40) (mm2) increase of PMA in the insulin group relative to the Exenatide group in patients with BMI<28 kg/m2 (p0.031) after adjusting for gender, age, and research center. Interaction analysis showed an interaction between BMI and treatment (p0.009). However, no interaction was observed among subgroups with a BMI≥28 kg/m2 or with different genders and ages.

CONCLUSION

Compared to exenatide, insulin glargine can relativity increase PMA in patients with T2DM having BMI<28 kg/m2 and NAFLD.

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

OBJECTIVE

To compare the effect of low-load blood flow restricted resistance training (BFR-RT) versus high-load resistance training (HL-RT) on muscle strength, muscle mass, physical function, patient-reported outcomes, and adherence to training in clinical musculoskeletal populations.

DATA SOURCES

Web of Science, Cochrane Central, Medline, Embase, SportDiscus was searched on the 30th May 2022.

REVIEW METHODS

This study was conducted as a systematic review and meta-analysis. Randomized Controlled Trials (RCTs) were included if they (i) included patients, (ii) comprised of a BFR-RT intervention protocol and a group who performed HL-RT (≥ 70%1RM) for at least eight exercise sessions, and (iii) involved at least 1 exercise that targeted the lower limbs. The Cochrane Risk of Bias tool was used to evaluate the risk of bias. The meta-analyses were performed using a random effects model with an adjustment to the confidence interval.

RESULTS

Seven RCTs comprising 303 participants (BFR-RT: n = 151; HL-RT: n = 152) were identified. HL-RT and BFR-RT showed similar gains in dynamic (1-10RM) knee extensor strength and leg press strength, quadriceps cross sectional area, sit-to-stand performance, and patient reported pain and function. There was a moderate effect favoring BFR-RT for increasing maximal isometric knee extensor strength. The grading of certainty in evidence was low-to-very low for all outcome variables.

CONCLUSION

This systematic review and meta-analysis extends our current knowledge about BFR-RT and HL-RT as equally effective exercise methods for inducing gains in maximal muscle strength in healthy populations, by now also comprising patients suffering from various clinical musculoskeletal conditions. The certainty in the estimates was low-to-very low, prompting the inclusion of future higher-quality trials.

TRIAL REGISTRATION

PROSPERO ID (CRD42022337173). Registered June 18th 2022.

Blood Flow Restriction in Oncological Patients: Advantages and Safety Considerations

BACKGROUND

Cancer, being a highly widespread disease on a global scale, has prompted researchers to explore innovative treatment approaches. In this regard, blood flow restriction has emerged as a promising procedure utilized in diverse clinical populations with favorable results including improvements in muscle strength, cardiovascular function, and postoperative recovery. The aim of this systematic review was to assess the efficacy of blood flow restriction in cancer survivors.

METHODS

An investigation was carried out using various databases until February 2023: PubMed, Scientific Electronic Library Online, Physiotherapy Evidence Database, Scopus, Web of Science, Cochrane Plus, SPORTDiscus, Physiotherapy and Podiatry of the Complutense University of Madrid, ScienceDirect, ProQuest, Research Library, Cumulative Index of Nursing and Allied Literature Complete Journal Storage, and the gray literature. To assess the methodological quality of the studies, the PEDro scale was utilized, and the Cochrane Collaboration tool was employed to evaluate the risk of bias.

RESULTS

Five articles found that blood flow restriction was beneficial in improving several factors, including quality of life, physical function, strength, and lean mass, and in reducing postoperative complications and the length of hospital stay.

CONCLUSION

Blood flow restriction can be a viable and effective treatment option. It is important to note that the caution with which one should interpret these results is due to the restricted quantity of articles and significant variation, and future research should concentrate on tailoring the application to individual patients, optimizing load progression, ensuring long-term follow-up, and enhancing the methodological rigor of studies, such as implementing sample blinding.

The effectiveness and safety of blood flow restriction training for the post-operation treatment of distal radius fracture

INTRODUCTION

Distal radius fracture (DRF) is a common injury in the upper extremities. Blood flow restriction (BFR) has been proven to be effective in improving function in low-load training, which is suitable for post-op rehabilitation. We explored the effectiveness and safety of BFR therapy in DRF patients who underwent surgery.

MATERIALS AND METHODS

Thirty-five patients were randomly assigned to either the BFR or the regular training (RT; no BFR therapy) groups. All patients completed the same 4-week postoperative rehabilitation program, including anti-inflammatory treatments, strengthening and range of motion (ROM) training. In the BFR group, the pressure was 120 mmHg in strengthening training course. Pain, circumferences of wrists and forearms, ROM, muscle strength, and D-dimer levels were evaluated at weeks 0, 2, and 4. Radius union scoring system (RUSS) was measured at weeks 4 and 12. Finally, wrist functionality (Cooney modification) was evaluated at week 12.

RESULTS

The BFR group had significantly decreased pain levels compared with the RT group (p < 0.01, effect size= 2.33, -2.44 at weeks 2 and 4). Swelling was effectively relieved in both groups. The wrist swelling was less in the BFR group (p < 0.01, effect size = -2.17 at week 4). The isometric strength of wrist extension (p < 0.01, effect size = 1.5, 3.02 at weeks 2 and 4), flexion (p < 0.01, effect size = 1.33, 2.53 at weeks 2 and 4), and functionality significantly increased in the BFR group (p < 0.01, effect size = 2.80 at week 12). No risk of VT in the BFR group was found. BFR did not threaten bone healing.

CONCLUSIONS

In patients with DRF who underwent corrective surgery, BFR therapy effectively relieved pain and swelling, increased muscle strength and wrist function, and had no additional risks for bone healing and VT.

Application and progress of blood flow restriction training in improving muscle mass and strength in the elderly

As an emerging training method, blood flow restriction training has been proved to promote the growth of muscle mass and strength. In recent years, it has been gradually applied in different populations. However, there are few studies on how blood flow restriction training affects muscle mass and strength in the elderly. The relevant literature is compiled and summarized in this study. Through the comparison of blood flow restriction training with traditional training methods and its application in the elderly, it shows that blood flow restriction training can effectively increase muscle mass and strength, prevent muscle atrophy, improve cardiopulmonary function, facilitate injury and postoperative rehabilitation, and intervene in related degenerative diseases as a training method suitable for the elderly,. The main mechanism of blood flow restriction training promoting muscle mass and strength growth is metabolic stress response, including muscle fiber recruitment, protein synthesis signal pathway activation, hormone secretion, etc., and is also related to cell swelling caused by pressure. At present, although the application of blood flow restriction training in the elderly population is increasing, there is a lack of personalized programs. In the future, more research on the dose effect and safety of blood flow restriction training is needed to develop more accurate personalized training programs.

Effects of Neuromuscular Electrical Stimulation and Blood Flow Restriction in Rehabilitation after Anterior Cruciate Ligament Reconstruction

The present study aimed to examine and compare the effects of a rehabilitation exercise (RE) using neuromuscular electrical stimulation (NMES) and blood flow restriction (BFR) on muscle function and knee functional abilities in patients who underwent anterior cruciate ligament reconstruction (ACLR). A total of 45 patients who underwent ACLR (28.76 ± 0.8 years; 34 males and 11 females) were retrospectively divided into three groups: control (CON, n = 15), NMES (n = 15), and BFR (n = 15). All participants carried out the RE program for 60 min, thrice a week for 12 weeks. The Lysholm score, International Knee Documentation Committee (IKDC) subjective score, thigh circumference at 5 cm from the knee joint, Y-balance posterior medial, and lateral significantly increased in all groups via intervention (p < 0.05). However, NMES showed a higher thigh circumference at 15 cm from the knee joint than CON via intervention (p < 0.05), and the strength and endurance of quadriceps femoris and hamstrings and Y-balance anterior showed a significant increase via intervention in NMES and BFR compared with CON (p < 0.05). In conclusion, we confirmed that RE using NMES and BFR effectively enhances muscle function and balance in ACLR patients.

Greater Neuromuscular Fatigue Following Low Load Blood Flow Restriction than Non Blood Flow Restriction Resistance Exercise Among Recreationally Active Men

PURPOSE

The purpose of this study was to examine the acute effects of low-load blood flow restriction (LLBFR) and low-load non-BFR (LL) on neuromuscular function following a bout of standardized, fatiguing leg extension muscle actions.

METHODS

Fourteen men (mean age ± SD = 23±4 yrs) volunteered to participate in this investigation and randomly performed LLBFR and LL on separate days. Resistance exercise consisted of 75 isotonic, unilateral leg extension muscle actions performed at 30% of one-repetition maximum. Prior to (pretest) and after (posttest) performing each bout of exercise, strength and neural assessments were determined.

RESULTS

There was no pretest to posttest differences between LLBFR and LL for maximal voluntary isometric contraction (MVIC) torque or V-wave/M-wave responses (muscle compound action potentials assessed during a superimposed MVIC muscle action) which exhibited decreases (collapsed across condition) of 41.2% and 26.2%, respectively. There were pretest to posttest decreases in peak twitch torque (36.0%) and sEMG (29.5%) for LLBFR but not LL, and larger decreases in voluntary activation for LLBFR (11.3%) than LL (4.5%).

CONCLUSIONS

These findings suggested that LLBFR elicited greater fatigue-induced decreases in several indices of neuromuscular function relative to LL. Despite this, both LLBFR and LL resulted in similar decrements in performance as assessed by maximal strength.

Blood Flow Restriction Training-An Overview and Implication in New Generation Physical Therapy: A Narrative Review

Blood Flow Restriction Training (BFRT) is a novel strengthening technique utilitarian in many conditions. But there is lack of exploration on this clinical intervention. The training can prove to be a boon in many conditions such as muscle weakness, degenerative among others. It can serve to be an essential treatment in prevention of disuse atrophy occurring on the initial days of bed-rest on post surgical patients and improve circulation. BFRT with aerobic activities can improve cardiovascular fitness and holistically help in rehabilitation. The electronic databases such as PubMed, ScienceDirect, Scopus and Google Scholars were reviewed including the reference lists to retrieve relevant information regarding the topic. The result of the review states that BFRT is a novel strength training program that has not been explored in India but is very effective, less expensive and innovative way of rehabilitation. The utility of BFRT is evident in post-operative disuse atrophy in the initial days of bed-rest. The evidence depict that BFRT is a very effective training modality that can efficiently improve the muscle function, strength and mass.

A Useful Blood Flow Restriction Training Risk Stratification for Exercise and Rehabilitation

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.

Metabolic and hormonal responses to chronic blood-flow restricted resistance training in chronic kidney disease: a randomized trial

Maintenance of glycemic and lipemic homeostasis can limit the progression of diabetic kidney disease. Resistance training (RT) is effective in controlling glycemia and lipemia in kidney disease; however, the effect of RT with blood flow restriction (RT+BFR) on these metabolic factors has not been investigated. We aimed to verify if chronic (6 months) RT and RT+BFR performed by patients with stage-2 chronic kidney disease (CKD) improves their glycemic homeostasis and immunometabolic profiles. Patients with CKD under conservative treatment (n = 105 (33 females)) from both sexes were randomized into control (n = 35 (11 females); age 57.6 ± 5.2 years), RT (n = 35 (12 females); age 58.0 ± 6.2 years), and RT+BFR (n = 35 (10 females); 58.0 ± 6.4 years) groups. Chronic RT or RT+BFR (6 months) was performed 3 times per week on non-consecutive days with training loading adjusted every 2 months, RT 50%-60%-70% of 1RM, and RT+BFR 30%-40%+50% of 1RM and fixed repetition number. Renal function was estimated with the glomerular filtration rate and serum albumin level. Metabolic, hormonal, and inflammatory assessments were analyzed from blood samples. Six months of RT and RT+BFR were similarly effective in improving glucose homeostasis and hormone mediators of glucose uptake (e.g., irisin, adiponectin, and sirtuin-1), decreasing pro-inflammatory and fibrotic proteins, and attenuating the progression of estimated glomerular filtration rate. Thus, RT+BFR can be considered an additional exercise modality to be included in the treatment of patients with stage 2 chronic kidney disease. Trial registration number: U1111-1237-8231. URL: http://www.ensaiosclinicos.gov.br/rg/RBR-3gpg5w/, no. RBR-3gpg5w. Novelty: Glycemic regulation induced by resistance training prevents the progression of CKD. Chronic RT and RT+BFR promote similar changes in glycemic regulation. RT and RT+BFR can be considered as non-pharmacological tools for the treatment of CKD.

Optimization of Exercise Countermeasures to Spaceflight Using Blood Flow Restriction

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.

Effects of combined treatment with blood flow restriction and low-current electrical stimulation on capillary regression in the soleus muscle of diabetic rats

To clarify the preventive effects of low-current electrical stimulation (ES) under blood flow restriction (Bfr) on diabetes-associated capillary regression in skeletal muscles, we assessed the changes in three-dimensional capillary architecture and angiogenic factors. Twenty-four Goto-Kakizaki rats were randomly divided into four groups: the sedentary diabetes mellitus (DM), Bfr (DM + Bfr), electrical stimulation (DM + ES), and Bfr plus ES (DM + Bfr + ES) groups. Six healthy Wistar rats were used as age-matched controls. Bfr was performed using pressure cuffs (80 mmHg) around the thighs of the rats, and low-current ES was applied to the calf muscles of the rats. The current intensity was set at 30% of the maximal isometric contraction (24-30 mA). The treatments were delivered three times a week for 8 wk. In the DM group, the capillary diameter and volume of the soleus muscle decreased, and, the antiangiogenic factor level increased. Furthermore, DM caused an increase in the hypoxia-inducible factor. Individually, Bfr or ES treatments failed to inhibit the DM-associated capillary regression and increase in antiangiogenic factor. However, combined treatment with Bfr and ES prevented DM-associated capillary regression via inhibition of the increased antiangiogenic factor and enhancement of interleukin-15 expression, mitochondrial biogenesis factors, and a proangiogenic factor. Therefore, DM-associated capillary regression inhibited by the combined treatment may prevent the effects of the increased antiangiogenic factor and enhance the proangiogenic factor.NEW & NOTEWORTHY The combined treatment of blood flow restriction and low intensity electrical stimulation attenuated type 2 diabetes (T2D)-associated capillary regression in the skeletal muscles. The treatment inhibits the T2D-associated increase in antiangiogenic factors via inhibition of intramuscular chronic hypoxia; it can inhibit intramuscular chronic hypoxia by enhancing proangiogenic factors. These results suggest that the combined treatment may be an effective therapeutic intervention for the prevention of T2D-associated capillary regression in the skeletal muscles.

The Impact of Diet and Exercise on Drug Responses

It is well known that lifestyle changes can alter several physiological functions in the human body. For exercise and diet, these effects are used sensibly in basic therapies, as in cardiovascular diseases. However, the physiological changes induced by exercise and a modified diet also have the capacity to influence the efficacy and toxicity of several drugs, mainly by affecting different pharmacokinetic mechanisms. This pharmacological plasticity is not clinically relevant in all cases but might play an important role in altering the effects of very common drugs, particularly drugs with a narrow therapeutic window. Therefore, with this review, we provide insights into possible food–drug and exercise–drug interactions to sharpen awareness of the potential occurrence of such effects.