Blood flow restriction attenuates eccentric exercise-induced muscle damage without perceptual and cardiovascular overload

75-repetition versus sets to failure of blood flow restriction exercise on indices of muscle damage in women

ABSTRACTThere is conflicting evidence regarding the prevalence and magnitude of exercise-induced muscle damage (EIMD) following low-load resistance exercise with blood flow restriction (LL + BFR) that may be related to exercise protocols. The purpose of this investigation was to examine the effects of 75-repetition (BFR-75) (1 × 30, 3 × 15) and 4 sets to failure (BFR-4x) protocols on indices of EIMD among untrained women. Thirteen women completed this investigation. One leg was randomly assigned to BFR-75 and the other to BFR-4x. Each leg performed isokinetic, unilateral, concentric-eccentric, leg extension muscle actions at 30% of maximal strength. Indices of EIMD (muscle soreness, range of motion [ROM], limb circumference, pain pressure threshold [PPT], and maximal voluntary isometric contraction [MVIC]) were recorded before exercise, 0-, 24-, 48-, 72-, and 96-hours post-exercise. There were no changes for ROM, circumference, or PPT. Muscle soreness increased similarly in both conditions 0-, 24-, and 48-hours post-exercise and MVIC increased 24-, 48-, 72-, and 96-hours post-exercise. These findings suggested BFR-75 and BFR-4x were not associated with EIMD and elicited similar physiological responses. The increases in muscle soreness may be due to metabolic stress associated with LL + BFR protocols apart from EIMD.

Effect of Blood Flow Restriction Technique on Delayed Onset Muscle Soreness: A Systematic Review

Background and Objectives: The effect of the blood flow restriction technique (BFR) on delayed onset muscular soreness (DOMS) symptoms remains unclear. Since there is no consensus in the literature, the aim of the present study is to systematically identify and appraise the available evidence on the effects of the BFR technique on DOMS, in healthy subjects. Materials and Methods: Computerized literature search in the databases Pubmed, Google Scholar, EBSCO, Cochrane and PEDro to identify randomized controlled trials that assessed the effects of blood flow restriction on delayed onset muscular soreness symptoms. Results: Eight trials met the eligibility criteria and were included in this review, presenting the results of 118 participants, with a mean methodological rating of 6/10 on the PEDro scale. Conclusions: So far, there is not enough evidence to confirm or refute the influence of BFR on DOMS, and more studies with a good methodological basis are needed, in larger samples, to establish protocols and parameters of exercise and intervention. Data analysis suggests a tendency toward the proinflammatory effect of BFR during high restrictive pressures combined with eccentric exercises, while postconditioning BFR seems to have a protective effect on DOMS. Prospero ID record: 345457, title registration: “Effect of Blood Flow Restriction Technique on the Prevention of Delayed Onset Muscle Soreness: A Systematic Review”.

Acute effects of resistance exercise with blood flow restriction on cardiovascular response: a meta-analysis

Aim: To compare the acute effects of low-load resistance training associated with blood flow restriction (LLRT-BFR) with low-load resistance training (LLRT) and high-load resistance training (HLRT) on cardiovascular outcomes in healthy individuals. Methods: This review was registered and the studies were selected using seven databases. Randomized controlled clinical trials were included that evaluated LLRT-BFR compared with LLRT and HLRT in young individuals for the cardiovascular outcomes. Results: 19 studies were included. In the comparison of LLRT-BFR with HLRT, there were significant differences for cardiac output and heart rate - with reduced values and in favor of LLRT-BFR. Conclusion: There are no greater acute effects of the addition of blood flow restriction, with the exception of the reduction in cardiac output and heart rate for LLRT-BFR compared with HLRT.

Acute hemodynamic responses from Low- load resistance exercise with blood flow restriction in young and older individuals: A Systematic Review and Meta-Analysis of Cross-Over Trials

OBJECTIVE

To summarize the existing evidence on the acute response of low-load (LL) resistance exercise (RE) with blood flow restriction (BFR) on hemodynamic parameters.

DATA SOURCES

MEDLINE (via PubMed), EMBASE (via Scopus), SPORTDiscus, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, Web of Science, and MedRxiv databases were searched from inception to February 2022.

REVIEW METHODS

Cross-over trials investigating the acute effect of LLRE+BFR vs. passive (no exercise) and active control methods (LLRE or HLRE) on heart rate (HR), systolic (SBP), diastolic (DBP), and mean (MBP) blood pressure responses.

RESULTS

The quality of the studies was assessed using the PEDro scale, risk of bias using the RoB 2.0 tool for cross-over trials, and certainty of the evidence using the GRADE method. A total of 15 randomized cross-over studies with 466 participants were eligible for analyses. Our data showed that LLRE+BFR increases all hemodynamic parameters compared to passive control, but not compared to conventional resistance exercise. Subgroup analysis did not demonstrate any differences between LLRE+BFR and low- (LL) or high-load (HL) resistance exercise protocols. Studies including younger volunteers presented higher chronotropic responses (HR) than those with older volunteers.

CONCLUSIONS

Despite causing notable hemodynamic responses compared to no exercise, the short-term low-load resistance exercise with BFR modulates all hemodynamic parameters HR, SBP, DBP, and MBP, similarly to a conventional resistance exercise protocol, whether at low or high-intensity. The chronotropic response is slightly higher in younger healthy individuals despite the similarity regarding pressure parameters. This article is protected by copyright. All rights reserved.

Post-activation Performance Enhancement after a Bout of Accentuated Eccentric Loading in Collegiate Male Volleyball Players

The purpose of this study was to investigate the benefit of post-activation performance enhancement (PAPE) after accentuated eccentric loading (AEL) compared to traditional resistance loading (TR). Sixteen male volleyball athletes were divided in AEL and TR group. AEL group performed 3 sets of 4 repetitions (eccentric: 105% of concentric 1RM, concentric: 80% of concentric 1RM) of half squat, and TR group performed 3 sets of 5 repetitions (eccentric & concentric: 85% of 1RM). Countermovement jump (CMJ), spike jump (SPJ), isometric mid-thigh pull (IMTP), and muscle soreness test were administered before (Pre) exercise, and 10 min (10-min), 24 h (24-h), and 48 h (48-h) after exercise. A two-way repeated measures analysis of variance was used to analyze the data. Peak force and rate of development (RFD) of IMTP in AEL group were significantly greater (p < 0.05) than TR group. The height, peak velocity, and RFD of CMJ, height of SPJ, and muscle soreness showed no interaction effects (p > 0.05) groups x time. AEL seemed capable to maintain force production in IMTP, but not in CMJ and SPJ. It is recommended the use of accentuated eccentric loading protocols to overcome the fatigue.

The effects of blood flow restriction resistance training on indices of delayed onset muscle soreness and peak power

BACKGROUND: Low-load resistance training with blood flow restriction (LL + BFR) attenuated delayed onset muscle soreness (DOMS) under some conditions. OBJECTIVE: The purpose of this study examined the effects of reciprocal concentric-only elbow flexion-extension muscle actions at 30% of peak torque on indices of DOMS. METHODS: Thirty untrained women (mean ± SD; 22 ± 2.4 years) were randomly assigned to 6 training days of LL + BFR (n= 10), low-load non-BFR (LL) (n= 10), or control (n= 10). Participants completed 4 sets (1 × 30, 3 × 15) of submaximal (30% of peak torque), unilateral, isokinetic (120∘s-1) muscle actions. Indices of DOMS including peak power, resting elbow joint angle (ROM), perceived muscle soreness (VAS), and pain pressure threshold (PPT) were assessed. RESULTS: There were no changes in peak power, ROM, or VAS. There was a significant interaction for PPT. Follow-up analyses indicated PPT increased for the LL + BFR condition (Day 5 > Day 2), but did not decrease below baseline. The results of the present study indicated LL + BFR and LL did not induce DOMS for the elbow extensors in previously untrained women. CONCLUSION: These findings suggested LL + BFR and LL concentric-only resistance training could be an effective training modality to elicit muscular adaptation without inducing DOMS.

Effect of resistance training with blood flow restriction on muscle damage markers in adults: A systematic review

Background

The purpose of this review was to systematically analyze the evidence regarding the occurrence of muscle damage (changes in muscle damage markers) after resistance training with blood flow restriction sessions.

Materials and methods

This systematic review was conducted in accordance with the PRISMA recommendations. Two researchers independently and blindly searched the following electronic databases: PubMed, Scopus, Web of Science, CINAHL, LILACS and SPORTdicus. Randomized and non-randomized clinical trials which analyzed the effect of resistance training with blood flow restriction on muscle damage markers in humans were included. The risk of bias assessment was performed by two blinded and independent researchers using the RoB2 tool.

Results

A total of 21 studies involving 352 healthy participants (men, n = 301; women, n = 51) were eligible for this review. The samples in 66.6% of the studies (n = 14) were composed of untrained individuals. All included studies analyzed muscle damage using indirect markers. Most studies had more than one muscle damage marker and Delayed Onset Muscle Soreness was the measure most frequently used. The results for the occurrence of significant changes in muscle damage markers after low-load resistance training with blood flow restriction sessions were contrasting, and the use of a pre-defined repetition scheme versus muscle failure seems to be the determining point for this divergence, mainly in untrained individuals.

Conclusions

In summary, the use of sets until failure is seen to be determinant for the occurrence of significant changes in muscle damage markers after low-load resistance training with blood flow restriction sessions, especially in individuals not used to resistance exercise.

Trial registration

Register number: PROSPERO number: CRD42020177119.

Low-load resistance training with blood flow restriction prevent renal function decline: The role of the redox balance, angiotensin 1-7 and vasopressin✰,✰✰

AIMS

We sought to investigate the effect of resistance training (RT) and low-load RT with moderate blood flow restriction (RT+BFR) on blood pressure, exercise pressor response, redox balance and vasoactive peptides, body composition and muscle strength in patients with stage two of chronic kidney disease (CKD).

METHODS

We conducted a 6-month randomized controlled exercise intervention in 90 male and female hypertensive CKD patients (58±9 years with estimated glomerular filtration rate (eGFR; of 66.1 ± 1.2 mL/kg/1.73m²). Participants were randomized to one of three groups (n = 30/group); control group (CTL), RT, and RT+BFR. RT and RT+BFR performed three weekly training sessions using similar periodization for six months (two-month mesocycles), but of different intensities.

RESULTS

There was similarly effects between RT and RT+BFR in reducing systolic and diastolic blood pressure during daytime and 24hour period (RT: 10.4%; RT+BFR: 10.3% of decrease), fat mass, F₂-isoprostanes, asymmetric dimethylarginine (ADMA) and vasopressin (p<0.05 pre-vs post). Also promoted the increase of angiotensin 1-7, nitric oxide (NO), catalase, Trolox equivalent and muscle strength (p<0.05). Both training models attenuated the decline of estimated glomerular filtration rate (p<0.0001 vs CTL). However, only RT+BFR was associated with lower discomfort during exercise (p<0.0001 pre-vs post). Statistical significance was considered with p < 0.05.

CONCLUSION

These findings suggest low-load RT+BFR as a promising non-pharmacological strategy to control blood pressure, oxidative stress, vasoactive peptides, and consequently, attenuate the decrease of the eGFR.

Patterns of responses and time-course of changes in muscle size and strength during low-load blood flow restriction resistance training in women

PURPOSE

The purpose of this investigation was to examine the individual and composite patterns of responses and time-course of changes in muscle size, strength, and edema throughout a 4 week low-load blood flow restriction (LLBFR) resistance training intervention.

METHODS

Twenty recreationally active women (mean ± SD; 23 ± 3 years) participated in this investigation and were randomly assigned to 4 weeks (3/week) of LLBFR (n = 10) or control (n = 10) group. Resistance training consisted of 75 reciprocal isokinetic forearm flexion-extension muscle actions performed at 30% of peak torque. Strength and ultrasound-based assessments were determined at each training session.

RESULTS

There were quadratic increases for composite muscle thickness (R² = 0.998), concentric peak torque (R² = 0.962), and maximal voluntary isometric contraction (MVIC) torque (R² = 0.980) data for the LLBFR group. For muscle thickness, seven of ten subjects exceeded the minimal difference (MD) of 0.16 cm during the very early phase (laboratory visits 1-7) of the intervention compared to three of ten subjects that exceeded MD for either concentric peak torque (3.7 Nm) or MVIC (2.2 Nm) during this same time period. There was a linear increase for composite echo intensity (r² = 0.563) as a result of LLBFR resistance training, but eight of ten subjects never exceeded the MD of 14.2 Au.

CONCLUSIONS

These findings suggested that the increases in muscle thickness for the LLBFR group were not associated with edema and changes in echo intensity should be examined on a subject-by-subject basis. Furthermore, LLBFR forearm flexion-extension resistance training elicited real increases in muscle size during the very early phase of training that occurred prior to real increases in muscle strength.

Walking exercise and lower-body blood flow restriction: Effects on systemic inflammation, lipid profiles and hematological indices in overweight middle-aged males

The objective of present study is to investigate the effects of walk training with and without blood flow restriction (BFR and no-BFR) on lipid profiles, inflammatory and haematological factors in over-weighed men. Participants were divided into BFR (n = 9) or no-BFR (n = 9) groups. Both groups were exposed to 8-week walk training on a treadmill: 3 sessions/week at a speed of 50 m/min, 5 sets × 2 min/session. There were differences in pre- to post-levels of (TG) and fibrinogen in the BFR group (p ≤ 0.05) that were accompanied by changes in red blood cells (RBC), haemoglobin (HGB) and haematocrit (HCT) levels (p ≤ 0.05). RBC levels were increased in the BFR group (p ≤ 0.05). The groups differed in their mean corpuscular volume (MCV) and mean corpuscular haemoglobin concentration (MCHC). These findings suggest the efficiency of BFR walk training in individuals exposed to chronic diseases associated with overweight, such as metabolic syndrome.

Acute Effects of Resistance Exercise With Blood Flow Restriction in Elderly Women: A Pilot Study

AIM

To compare the acute effects of two resistance exercise sessions with different partial blood flow restrictions (BFR) on hemodynamic parameters and cardiac autonomic modulation in older women with metabolic syndrome.

METHODS

Thirty-nine older women (64.4 ± 4.5 years) were allocated into three groups: BFR0 = resistance exercise (20%, 1 maximum repetition [MR]) + 0% BFR; BFR60 = 20% 1 MR resistance exercise + 60% BFR; and BFR80 = 20% 1MR resistance exercise + 80% BFR.

RESULTS

A reduction of 14 mmHg (BFR60 group) and 13 mmHg (BRF80 group) was observed 48 hr after the first exercise session, while vagal modulation was increased in the BRF60 group after 24 and 48 hr.

CONCLUSION

A low-intensity resistance exercise session with 60% and 80% of BFR resulted in blood pressure (systolic, diastolic, and mean) reduction and positive changes on heart rate variability after 24 h of a RE session.

Metabolic Demand and Indirect Markers of Muscle Damage After Eccentric Cycling With Blood Flow Restriction

Purpose: To compare the effects of a single bout of eccentric cycling (ECC) and eccentric cycling with blood flow restriction (ECC_BFR) on the changes in cardio-metabolic demand and indirect markers of muscle damage in healthy men. Method: Twenty-one young men (24.0 ± 3.2 y) were randomly allocated in two groups to perform a 30-min eccentric cycling bout with or without blood flow restriction. Oxygen consumption, heart rate, rate of perceived exertion and mean arterial blood pressure were monitored during cycling. Blood lactate was measured before and after cycling. Maximal voluntary isometric knee extensor strength and muscle damage were measured before, immediately after and 1-4 days after each eccentric cycling bout. Results: Oxygen consumption, heart rate, rate of perceived exertion and mean arterial blood pressure were similar between bouts. Blood lactate concentrations increased in both groups (p < .01), with ECC_BFR showing 60% greater blood lactate concentration than eccentric cycling (p < .01). Maximal voluntary isometric knee extensor strength decreased 19-7% until 48 h and decreased 16-7% until 72 h after ECC and ECC_BFR, respectively. Muscle soreness and pressure pain threshold remained elevated until 72 h after ECC and until 96 h after ECC_BFR. Conclusion: These results show that ECC_BFR induces similar cardiovascular stress, greater lactate production and longer time to recover than ECC alone. Thus, BFR can be safely implemented with eccentric cycling.

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

BACKGROUND

Blood flow restriction exercise has increasingly broad applications among healthy and clinical populations. Ensuring the technique is applied in a safe, controlled, and beneficial way for target populations is essential. Individualized cuff pressures are a favored method for achieving this. However, there remains marked inconsistency in how individualized cuff pressures are applied.

OBJECTIVES

To quantify the cuff pressures used in the broader blood flow restriction exercise literature, and determine whether there is clear justification for the choice of pressure prescribed.

METHODS

Studies were included in this review from database searches if they employed an experimental design using original data, involved either acute or chronic exercise using blood flow restriction, and they assessed limb or arterial occlusion pressure to determine an individualized cuff pressure. Methodologies of the studies were evaluated using a bespoke quality assessment tool.

RESULTS

Fifty-one studies met the inclusion criteria. Individualized cuff pressures ranged from 30% to 100% arterial occlusion pressure. Only 7 out of 52 studies attempted to justify the individualized cuff pressure applied during exercise. The mean quality rating for all studies was 11.1 ± 1.2 out of 13.

CONCLUSIONS

The broader blood flow restriction exercise literature uses markedly heterogeneous prescription variables despite using individualized cuff pressures. This is problematic in the absence of any clear justification for the individualized cuff pressures selected. Systematically measuring and reporting all relevant acute responses and training adaptations to the full spectrum of BFR pressures alongside increased clarity around the methodology used during blood flow restriction exercise is paramount.

Eccentric and concentric blood flow restriction resistance training on indices of delayed onset muscle soreness in untrained women

PURPOSE

Unaccustomed exercise can result in delayed onset muscle soreness (DOMS), particularly as a result of the eccentric phase of the muscle contraction. Resistance training combined with venous blood flow restriction (vBFR) may attenuate DOMS, but the available information in this regard is conflicting. Therefore, the purpose of this study was to examine the effects of low-load eccentric vBFR (Ecc-vBFR) and concentric vBFR (Con-vBFR) resistance training on indices of DOMS.

METHODS

Twenty-five previously untrained women completed seven days of either Ecc-vBFR (n = 12) or Con-vBFR (n = 13) forearm flexion resistance training at a velocity of 120° s^-1 on an isokinetic dynamometer. The Ecc-vBFR group used a training load that corresponded to 30% of eccentric peak torque and the Con-vBFR group used a training load that corresponded to 30% of concentric peak torque.

RESULTS

There were no differences between Ecc-vBFR and Con-vBFR at any of the seven training sessions on any of the indices of DOMS. There were no decreases in the maximal voluntary isometric contraction torque which increased at days 6 and 7. Similarly, there were no changes in perceived muscle soreness, pain pressure threshold, elbow joint angle, or edema (as assessed by echo intensity via ultrasound) across the seven training sessions.

CONCLUSIONS

The Ecc-vBFR and Con-vBFR low-load training protocols were not associated with DOMS and there were no differences between protocols when performed using the same relative training intensity. These findings suggested that both unaccustomed eccentric and concentric low-load training did not result in DOMS when combined with vBFR.

Muscle damage responses to resistance exercise performed with high-load versus low-load associated with partial blood flow restriction in young women

The aim of this study was to compare if an acute exercise session of high-load resistance training (HL-RT, e.g. 70% of 1 repetition-maximum, 1 RM) induces a higher magnitude of muscle damage compared with a RT protocol with low-loads (e.g. 20% 1 RM) associated with partial blood flow restriction (LL-BFR), and investigate the recovery in the days after the protocols. We used an unilateral crossover research design in which 10 young women (22(2) y; 162(5) cm; 66(11) kg) performed HL-RT and LL-BFR in a randomized, counterbalanced manner with a minimum interval of 2 weeks between protocols. Indirect muscle damage markers were evaluated before and once a day for 4 days into recovery. Main results showed decreases of 8-12% at 24-48 h in maximal voluntary isometric and concentric contraction torques (P < 0.03), and changes in muscle architecture markers (P < 0.03) for HL-RT and LL-BFR, with no differences between protocols (P > 0.05). Moreover, delayed onset muscle soreness increased only after LL-BFR (P < 0.001). We conclude that an acute bout of low volume HL-RT or LL-BFR to failure resulted in edema-induced muscle swelling, but do not induce major or long-lasting decrements in muscle function and the level of soreness promoted from LL-BFR was mild.