Aerobic Training With Blood Flow Restriction on Muscle Hypertrophy and Strength: Systematic Review and Meta-analysis.

ABSTRACT: de Lemos Muller, CH, Farinha, JB, Leal-Menezes, R, and Ramis, TR. Aerobic training with blood flow restriction on muscle hypertrophy and strength: systematic review and meta-analysis. J Strength Cond Res 38(7): 1341-1349, 2024-Integrating strength and endurance training in a single exercise session, even on separate days, can be physically demanding and time-consuming. Therefore, there is a growing interest in identifying efficient training methods that can concurrently enhance cardiovascular and neuromuscular performance through a singular training modality. This study conducted a systematic review and meta-analysis to explore the effects of aerobic training with blood flow restriction (AT + BFR) on muscle hypertrophy and strength gains in healthy individuals. Our study was registered at PROSPERO and used multiple databases (PubMed, Embase, Scopus, and Web of Science), seeking clinical trials that examined AT + BFR influence on muscle hypertrophy and strength gains in individuals aged 18-60 years and comparing with aerobic training without BFR. The risk of bias and method quality were assessed using the ROB2.0 tool and PEDro scale, respectively, and the quality of evidence was evaluated with the GRADE method. A random-effects model was used for meta-analysis, and standardized mean difference (SMD) was calculated for each outcome. Of 4,462 records, 29 full texts were assessed for eligibility, with 7 articles meeting the inclusion criteria. The results indicated that AT + BFR was more beneficial for inducing muscle hypertrophy than aerobic training without BFR (SMD [95% CI] = 0.86 [0.37-1.35]; I2 = 42%). Furthermore, AT + BFR was associated with greater improvements in muscle strength (SMD [95% CI] = 0.41 [0.10-0.72]; I2 = 0%). Despite the generally high risk of bias for both outcomes, these encouraging findings underscore the clinical significance of AT + BFR as a compelling tool for enhancing neuromuscular parameters.

Acute Responses in Blood Flow Restriction Low-intensity Aerobic Training: A Meta-analysis.

The purpose was to determine the effect low-intensity training with blood flow restriction (LI-BFR) versus high-intensity aerobic training (HIT) on acute physiological and perceptual responses. The Cumulative Index to Nursing and Allied Health Literature, National Library of Medicine, Scopus, SPORTDiscus and Web of Science databases and the reference list of eligible studies were consulted to identify randomized experimental studies, published until July 4, 2022, that analyzed physiological or perceptual responses between LI-BFR versus HIT in healthy young individuals. Mean difference (MD) and standardized mean difference (SMD) were used as effect estimates and random effects models were applied in all analyses. Twelve studies were included in this review. During exercise sessions, HIT promoted higher values of heart rate (MD=28.9 bpm; p<0.00001; I 2 =79%), oxygen consumption (SMD=4.01; p<0.00001; I 2 =83%), ventilation (MD=48.03 l/min; p=0.0001; I 2 =97%), effort (SMD=1.54; p=0.003; I 2 =90%) and blood lactate (MD=3.85 mmol/L; p=0.002; I 2 =97%). Perception of pain/discomfort was lower in HIT (SMD=-1.71; p=0.04; I 2 =77.5%). In conclusion, LI-BFR promotes less pronounced physiological responses than HIT but with greater perception of pain.

Cardiovascular and Perceptual Responses to Resistance Training with Practical Blood Flow Restriction Induced by a Non-Elastic Band vs. Pneumatic Cuff: A Crossover Randomized Study.

Our purpose in this study was to analyze perceptual and cardiovascular responses in low-load resistance training (RT) sessions associated with a fixed non-elastic band compressed to the proximal region of the arms (p-BFR) versus a pneumatic cuff inflated to a pressure of 150 mmHg (t-BFR). Participants (16 healthy trained men) were randomly assigned to two conditions of low-load RT (20% one repetition maximum [1RM]) with BFR (p-BFR or t-BFR). In both conditions, the participants performed five exercises (4 sets/30-15-15-15) for the upper-limbs, but in one of the conditions, the exercises were performed with a p-BFR induced by a non-elastic band, while in the other, the exercises were performed with a t-BFR using a device with similar width. The devices used to generate the BFR had similar widths (5 cm). Brachial blood pressure (bBP) and heart rate (HR) were measured before, after each exercise and after the experimental session (5-, 10-, 15-, and 20 min post-session). Rating of perceived exertion (RPE) and rating of pain perception (RPP) were reported after each exercise and 15 minutes post-session. HR increased during the training session in both conditions, with no differences between p-BFR and t-BFR. Neither intervention increased diastolic BP (DBP) during training, but there was a significant post-session reduction in DBP in the p-BFR, with no differences observed between conditions. There were no significant differences in RPE and RPP in the two training conditions, with both conditions associated with higher RPE and RPP at the end versus beginning of the experimental session. We conclude that when BFR device width and material are similar, low-load training with t-BFR and p-BFR promotes similar acute perceptual and cardiovascular responses in healthy trained men.

AT1R blocker prevents mental stress induced retrograde blood flow in overweight/obese men.

The main goal was to determine the impact of mental stress (MS) on blood flow regulation in overweight/obese men. Fourteen overweight/obese men (27 ± 7 years; 29.8 ± 2.6 kg/m2 ) participated in two randomized experimental sessions with oral administration of the AT1R blocker Olmesartan (40 mg; AT1RB) or placebo (PL). After 2 h, a 5-min acute MS session (Stroop Color Word Test) was administered. Blood flow was assessed at baseline and during the first 3 min of MS by vascular ultrasound in the brachial artery. Blood was collected before (baseline) and during mental stress (MS) for measurement of nitrite (chemiluminescence) and endothelin-1 (ELISA kit). The AT1R blocker was able to reverse the MS responses observed in the placebo session for retrograde flow (p < 0.01), retrograde SR (p < 0.01) and oscillatory shear index (p = 0.01). Regarding vasoactive substances, no differences were observed in ET-1 (p > 0.05) responses to MS between experimental sessions. However, for nitrite responses, the administration of the AT1R blocker was able to increase circulating levels of NO (p = 0.03) Blockade of AT1R appears to prevent the decrease in endothelial function by reducing low shear stress and maintaining the vasoactive substances balance after MS in overweight/obese men.

Physiological adaptations and myocellular stress in short-term, high-frequency blood flow restriction training: A scoping review.

BACKGROUND: High frequency (1-2 times per day) low-intensity blood flow restriction (BFR) training has been recommended as a prescription approach for short durations of time to maximize relevant physiological adaptations. However, some studies demonstrate negative physiological changes after short periods of high-frequency BFR training, including prolonged strength decline and muscle fiber atrophy. OBJECTIVES: To provide a comprehensive overview of short-term, high-frequency blood flow restriction training, including main adaptations, myocellular stress, limitations in the literature, and future perspectives. METHODS: A systematic search of electronic databases (Scopus, PubMed®, and Web of Science) was performed from the earliest record to April 23, 2022. Two independent reviewers selected experimental studies that analyzed physical training protocols (aerobic or resistance) of high weekly frequency (>4 days/week) and short durations (≤3 weeks). RESULTS: In total, 22 studies were included in this review. The samples were composed exclusively of young predominantly male individuals. Muscle strength and hypertrophy were the main outcomes analyzed in the studies. In general, studies have demonstrated increases in strength and muscle size after short term (1-3 weeks), high-frequency low-intensity BFR training, non-failure, but not after control conditions (non-BFR; equalized training volume). Under failure conditions, some studies have demonstrated strength decline and muscle fiber atrophy after BFR conditions, accompanying increases in muscle damage markers. Significant limitations exist in the current HF-BFR literature due to large heterogeneities in methodologies. CONCLUSION: The synthesis presented indicates that short-term, high-frequency BFR training programs can generate significant neuromuscular adaptations. However, in resistance training to failure, strength declines and muscle fiber atrophy were reported. Currently, there are no studies analyzing low-frequency vs. high-frequency in short-term BFR training. Comparisons between resistance exercises of similar intensities (e.g., combined effort) are lacking, limiting conclusions on whether the effect is a product of proximity to failure or a specific effect of BFR.

Simpatectomía de la arteria radial y ulnar en contexto de úlcera digital secundaria a esclerosis sistémica cutánea localizada / Radial and ulnar artery sympathectomy in the context of digital ulcer secondary to localized cutaneous systemic sclerosis

SPeripheral sympathectomy is a procedure which has shown high rates of decreasing ischemic pain, recover functionality and wound healing, preventing the progression of the disease and further complications. We present a female patient with severe Raynaud´s phenomenon secondary to localized cutaneous systemic sclerosis complicated who presented digital ulcer treated with a sympathectomy of the radial and ulnar artery at the wrist level, undergoing post-operative follow-up.

Strength training with and without arteriovenous blood flow restriction improves performance, regardless of changes in muscle hypertrophy, in Wistar rats.

Strength training (ST) with blood flow restriction (BFR) is known to promote increases in hypertrophy and strength sometimes similar to traditional ST despite the effects of the arterial BFR on muscle adaptations and safety are not well established. The aim of this study was to assess whether ST with arterial BFR is able to improve muscular adaptations, performance and its safety in Wistar rats. Animals aging 8 weeks were divided in four groups: sedentary sham (S/S), sedentary with arterial BFR (S/BFR), trained sham (T/S), and trained with arterial BFR (T/BFR). Training protocol consisted of four weeks of ST composed by six sets of 10 ladder climbing with 50% of 1 maximal voluntary contraction. Body weight, epididymal fat, maximum loaded weight, manual grip strength, muscular hypertrophy index, systolic blood pressure, enzyme activity of superoxide dismutase, nitrite/nitrate concentration and tumor necrosis factor alpha were analyzed. The BFR rate was between 36% and 38%. T/BRF was effective to promote strength and hypertrophy. T/S is an alternative to improve strength, but it did not promote hypertrophy. Furthermore, we found no significant cardiac and metabolic changes. Thus, T/BFR is able to improve muscle adaptations and performance in rats, without causing cardiovascular and metabolic damage.

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 versus 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 LL 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.

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.

Relationship between heart rate variability and performance in eccentric training with blood flow restriction.

BACKGROUND: The resistance training with blood flow restriction (BFR) presents results in strength gain and muscle hypertrophy. However, there are no data that evaluate the long-term adaptation of the autonomic nervous system and its influence on the performance, especially with eccentric contractions. OBJECTIVE: To perform a systematic autonomous monitoring during eccentric training with BFR at different loads and to correlate them with possible changes in the performance METHODS: This is a 4-arms, randomized controlled and single blind trial. Sixty men were randomized in four groups: low and high load eccentric exercise (LL and HL); LL and HL with BFR (LL-BFR and HL-BFR). The participants underwent 18 sessions of eccentric exercise for the dominant quadriceps femoris muscle in the isokinetic dynamometer. The performance (strength through isometric, concentric and eccentric peaks torque on the isokinetic dynamometer and Single-leg Hop Test) was evaluated 1 week before, in the fourth week and 1 week after the end of the training programme. Heart rate variability (HRV) through vagal and global indices was evaluated daily for 15 min before each session. RESULTS: There was a significant correlation between performance and HRV for LL and HL-BFR groups, with an increase in parasympathetic indices in the first group and an increase in performance in the second group. CONCLUSION: HRV indices are correlated with performance. However, in the LL group, there was an increase in parasympathetic indices without repercussions on performance while, in the HL-BFR group, there was an increase in performance and no repercussion in the autonomic indices.

Exercise with blood flow restriction improves muscle strength and mass while preserving the vascular and microvascular function and structure of older adults.

BACKGROUND: Changes in muscle mass, strength, vascular function, oxidative stress, and inflammatory biomarkers were compared in older adults after resistance training (RT) performed with low-intensity without blood flow restriction (RT-CON); low-intensity with BFR (RT-BFR); and high-intensity without BFR (RT-HI). METHODS: Thirty-two untrained individuals (72±7 y) performed a 12-week RT after being randomized into three groups: RT-CON -30% of 1 repetition maximum (RM); RT-BFR -30% of 1RM and mild BFR (50% of arterial occlusion pressure); RT-HI -70% of 1 RM. RESULTS: Improvements in handgrip strength were similar in RT-BFR (17%) and RT-HI (16%) vs. RT-CON (-0.1%), but increases in muscle mass (6% vs. 2% and -1%) and IGF-1 (2% vs. -0.1% and -1.5%) were greater (p < 0.05) in RT-BFR vs. RT-HI and RT-CON. Changes in vascular function, morphology, inflammation, and oxidative stress were similar between groups, except for time to reach maximum red blood cell velocity which showed a greater reduction (p < 0.05) in RT-BFR (-55%) vs. RT-HI (-11%) and RT-CON (-4%). CONCLUSION: RT with low intensity and mild BFR improved muscle strength and mass in older individuals while preserving vascular function. This modality should be considered an adjuvant strategy to improve muscle function in older individuals with poor tolerance to high loads.

Muscle Fatigue Is Attenuated When Applying Intermittent Compared With Continuous Blood Flow Restriction During Endurance Cycling.

PURPOSE: The aim of this study was to identify a blood-flow-restriction (BFR) endurance exercise protocol that maximizes metabolic strain and minimizes muscle fatigue. METHODS: Twelve healthy participants accomplished 5 different interval cycling endurance exercises (2-min work, 1-min rest) in a randomized order: (1) control, low intensity with unrestricted blood flow (CON30); (2) low intensity with intermittent BFR (i-BFR30, ∼150 mm Hg); (3) low intensity with continuous BFR (c-BFR, ∼100 mm Hg); (4) unloaded cycling with i-BFR0 (∼150 mm Hg); and (5) high intensity (HI) with unrestricted blood flow. Force production, creatine kinase activity, antioxidant markers, blood pH, and potassium (K+) were measured in a range of 5 minutes before and after each cycling exercise protocol. RESULTS: HI showed the highest reduction (Δ = -0.26 [0.05], d = 5.6) on blood pH. Delta pH for c-BRF30 (Δ = -0.02 [0.03], d = 0.8) and Δ pH for i-BRF30 (Δ = -0.04 [0.03], d = 1.6) were different from each other, and both were higher compared with CON30 (Δ = 0.03 [0.03]). There was significant before-to-after force loss following HI (Δ = 55 [40] N·m-1, d = 1.5) and c-BFR30 (Δ = 27 [21] N·m-1, d = 0.7) protocols only, which were accompanied by significant increases in K+ (HI: Δ = 0.94 [0.65] mmol·L-1, d = 1.8; c-BFR30: Δ = 0.72 [0.85] mmol·L-1, d = 1.2). Moreover, all BFR conditions elicited slight increases in plasma creatine kinase, but not for HI and CON30. Glutathione changes from before to after were significant for all BFR conditions and HI, but not for CON30. CONCLUSIONS: The attenuation in fatigue-induced reductions in maximal force suggests that i-BFR exercise could be preferable to c-BFR in improving exercise capacity, with considerably less biologic stress elicited from HI exercises.

Aerobic exercise with blood flow restriction: Energy expenditure, excess postexercise oxygen consumption, and respiratory exchange ratio.

We compared the effects of aerobic exercise with and without blood flow restriction (BFR) to high-intensity aerobic exercise on energy expenditure (EE), excess Postexercise oxygen consumption (EPOC), and respiratory exchange ratio (RER) during and after exercise. Twenty-two recreationally active males randomly completed the following experimental conditions: AE-aerobic exercise without BFR, AE + BFR-aerobic exercise with BFR, HIAE-high-intensity aerobic exercise, CON-non-exercise control condition. EE was significantly (p < 0.05) greater during exercise for HIAE compared to all conditions, and for AE + BFR compared to AE and CON during and postexercise exercise. There were no significant (p > 0.05) differences in EPOC between HIAE and AE + BFR at any time point, however, both conditions were significantly (p < 0.05) greater than the AE (d = 1.50 and d = 1.03, respectively) and CON at the first 10 min postexercise. RER during exercise for HIAE was significantly (p < 0.05) greater than AE + BFR at the first 6 min of exercise (p = 0.003, d = 0.88), however, no significant differences were observed from 9 min up to the end of the exercise. HIAE was also significantly (p < 0.05) greater than AE and CON at all time points during exercise, whereas, AE + BFR was significantly (p < 0.05) greater than CON at all time points but not significantly (p < 0.05) different than AE (p < 0.05); although the overall session RER was significantly (p < 0.05) greater during AE + BFR than AE. Altogether, continuous AE + BFR results in greater EE compared to volume matched AE, as well as a similar EPOC compared to HIAE.

The Effect of Low-intensity Aerobic Training Combined with Blood Flow Restriction on Maximal Strength, Muscle Mass, and Cycling Performance in a Cyclist with Knee Displacement.

Low-intensity aerobic training combined with blood flow restriction (LI + BFR) has resulted in increases in aerobic and neuromuscular capacities in untrained individuals. This strategy may help cyclists incapable of training with high intensity bouts or during a rehabilitation program. However, there is a lack of evidence about the use of LI + BFR in injured trained cyclists. Thus, we investigated the effects of LI + BFR on aerobic capacity, maximal isometric strength, cross-sectional area of vastus lateralis (CSAVL), time to exhaustion test (TTE), and 20 km cycling time-trial performance (TT20 km) in a male cyclist with knee osteoarthritis (OA). After a 4-week control period, a 9-week (2 days/week) intervention period started. Pre- and post-intervention TT20 km, peak oxygen consumption (VO2peak), power output of the 1st and 2nd ventilatory thresholds (1st WVT and 2nd WVT), maximum power output (Wmax), TTE, muscle strength and CSAVL of both legs were measured. Training intensity was fixed at 30% of Wmax while the duration was progressively increased from 12 min to 24 min. There was a reduction in time to complete TT20 km (-1%) with increases in TT20 km mean power output (3.9%), VO2peak (11.4%), 2nd WVT (8.3%), Wmax (3.8%), TTE (15.5%), right and left legs maximal strength (1.3% and 8.5%, respectively) and CSAVL (3.3% and 3.7%, respectively). There was no alteration in 1st WVT. Based on the results, we suggest that LI + BFR may be a promising training strategy to improve the performance of knee-injured cyclists with knee OA.

Low-Load Blood-Flow Restriction Exercise to Failure and Nonfailure and Myoelectric Activity: A Meta-Analysis.

OBJECTIVE: To compare the short- and long-term effects of low-load resistance training with blood-flow restriction (LL-BFR) versus low- (LL-RT) or high- (HL-RT) load resistance training with free blood flow on myoelectric activity and investigate the differences between failure (exercise performed to volitional failure) and nonfailure (exercise not performed to volitional failure) protocols. DATA SOURCES: We identified sources by searching the MEDLINE, PubMed, CINAHL, Web of Science, CENTRAL, Scopus, SPORTDiscus, and PEDro electronic databases. STUDY SELECTION: We screened the titles and abstracts of 1048 articles using our inclusion criteria. A total of 39 articles were selected for further analysis. DATA EXTRACTION: Two reviewers independently assessed the methodologic quality of each study and extracted the data. A meta-analytic approach was used to compute standardized mean differences (SMDs) ± 95% CIs. Subgroup analyses were conducted for both failure and nonfailure protocols. DATA SYNTHESIS: The search identified 39 articles that met the inclusion criteria. Regarding the short-term effects, LL-BFR increased muscle excitability compared with LL-RT during nonfailure protocols (SMD = 0.61; 95% CI = 0.34, 0.88), whereas HL-RT increased muscle excitability compared with LL-BFR during failure (SMD = -0.61; 95% CI = -1.01, -0.21) and nonfailure (SMD = -1.13; 95% CI = -1.94, -0.33) protocols. Concerning the long-term effects, LL-BFR increased muscle excitability compared with LL-RT during exercises performed to failure (SMD = 1.09; 95% CI = 0.39, 1.79). CONCLUSIONS: Greater short-term muscle excitability levels were observed in LL-BFR than in LL-RT during nonfailure protocols. Conversely, greater muscle excitability was present during HL-RT than LL-BFR, regardless of volitional failure. Furthermore, LL-BFR performed to failure increased muscle excitability in the long term compared with LL-RT.

Patterns of vascular response immediately after passive mobilization in patients with sepsis: an observational transversal study.

Sepsis is a serious organ dysfunction leading to endothelial damage in critical patients. Physiologically, there is an augment of vascular diameter in response to increased vascular blood flow and shear stress stimulus. However, the pattern of vascular response in face of passive mobilization (PM), an early mobilization physical strategy, has not yet been explored in patients with sepsis. To explore patterns of vascular response to PM and associations with clinical and cardiovascular profile in patients with sepsis. Cross-sectional, single-arm study. Thirty-two patients diagnosed with sepsis were enrolled. Vascular response was assessed by flow-mediated dilation (FMD) using brachial artery ultrasound, before and after PM. The PM (to assess the response pattern) and SR (shear rate) were also calculated. PM protocol consisted of knees, hips, wrists, elbows, shoulders, dorsiflexion/plantar flexion movements 3 × 10 repetitions each (15 min). Arterial stiffness was assessed by Sphygmocor®, by analyzing the morphology and pulse wave velocity. Cardiac autonomic modulation (CAM) was assessed by analyzing heart rate variability indexes (mean HR, RMSSD, LF, HF, ApEn, SampEn, DFA). Different vascular responses were observed after PM: (1) increased vascular diameter (responders) (n = 13, %FMD = 11.89 ± 5.64) and (2) reduced vascular diameter (non-responders) (n = 19, %FMD= -7.42 ± 6.44). Responders presented a higher non-linear DFA2 index (p = 0.02). There was a positive association between FMD and DFA (r = 0.529; p = 0.03); FMD and SampEn (r = 0.633; p < 0.01). A negative association was identified between FMD and LF (Hz) (r= -0.680; p < 0.01) and IL-6 (r= -0.469; p = 0.037) and SR and CRP (r= -0.427; p = 0.03).

Relationships Between Regional Cerebral Blood Flow and Neurocognitive Outcomes in Children and Adolescents With Congenital Heart Disease.

To identify regional cerebral blood flow (rCBF) alterations in children and adolescents with congenital heart disease (CHD) in relation to neurocognitive outcomes using a nonbiased data-driven approach. This is a prospective, observational study of children and adolescents with CHD without brain injury and healthy controls using pseudo-continuous arterial spin labeling (pCASL) MRI. Quantitative rCBF was compared between participants with CHD and healthy controls using a voxelwise data-driven method. Mediation analysis was then performed on a voxelwise basis, with the grouping variable as the independent variable, neurocognitive outcomes (from the NIH Toolbox Cognitive Battery) as the dependent variables, and rCBF as the mediator. After motion correction, a total of 80 studies were analyzable (27 for patients with CHD, 53 for controls). We found steeper age-related decline in rCBF among those with CHD compared to normal controls in the insula/ventromedial prefrontal regions (salience network) and the dorsal anterior cingulate and precuneus/posterior cingulate (default mode network), and posterior parietal/dorsolateral prefrontal (central executive network) (FWE-corrected P< 0.05). The reduced rCBF in the default mode/salience network was found to mediate poorer performance on an index of crystallized cognition from the NIH Toolbox Cognitive Battery in those with CHD compared to controls. In contrast, reduced rCBF in the central executive network/salience network mediated reduced deficits in fluid cognition among patients with CHD compared to controls. Regional cerebral blood flow alterations mediate domain-specific differences in cognitive performance in children and adolescents with CHD compared to healthy controls, independent of injury, and are likely related to brain and cognitive reserve mechanisms. Further research is needed to evaluate the potential of interventions in CHD targeting regional cerebral blood flow across lifespan.

Perceptual and Neuromuscular Responses Adapt Similarly Between High-Load Resistance Training and Low-Load Resistance Training With Blood Flow Restriction.

ABSTRACT: Teixeira, EL, Painelli, VdS, Schoenfeld, BJ, Silva-Batista, C, Longo, AR, Aihara, AY, Cardoso, FN, Peres, BdA, and Tricoli, V. Perceptual and neuromuscular responses adapt similarly between high-load resistance training and low-load resistance training with blood flow restriction. J Strength Cond Res 36(9): 2410-2416, 2022-This study compared the effects of 8 weeks of low-load resistance training with blood flow restriction (LL-BFR) and high-load resistance training (HL-RT) on perceptual responses (rating of perceived exertion [RPE] and pain), quadriceps cross-sectional area (QCSA), and muscle strength (1 repetition maximum [RM]). Sixteen physically active men trained twice per week, for 8 weeks. One leg performed LL-BFR (3 sets of 15 repetitions, 20% 1RM), whereas the contralateral leg performed HL-RT (3 sets of 8 repetitions, 70% 1RM). Rating of perceived exertion and pain were evaluated immediately after the first and last training sessions, whereas QCSA and 1RM were assessed at baseline and after training. Rating of perceived exertion was significantly lower (6.8 ± 1.1 vs. 8.1 ± 0.8, p = 0.001) and pain significantly higher (7.1 ± 1.2 vs. 5.8 ± 1.8, p = 0.02) for LL-BFR than that for HL-RT before training. Significant reductions in RPE and pain were shown for both protocols after training (both p < 0.0001), although no between-protocol differences were shown in absolute changes ( p = 0.10 and p = 0.48, respectively). Both LL-BFR and HL-RT were similarly effective in increasing QCSA (7.0 ± 3.8% and 6.3 ± 4.1%, respectively; both p < 0.0001) and 1RM (6.9 ± 4.1% and 13.7 ± 5.9%, respectively; both P < 0.0001), although absolute changes for 1RM in HL-RT were greater than LL-BFR ( p = 0.001). In conclusion, LL-BFR produces lower RPE values and a higher pain perception than HL-RT. However, consistent application of these approaches result in chronic adaptations so that there are no differences in perceptual responses over the course of time. In addition, muscle strength is optimized with HL-RT despite similar increases in muscle hypertrophy between conditions.

Moderate-intensity exercise with blood flow restriction on cardiopulmonary kinetics and efficiency during a subsequent high-intensity exercise in young women: A cross-sectional study.

ABSTRACT: Blood flow restriction (BFR) training applied prior to a subsequent exercise has been used as a method to induce changes in oxygen uptake pulmonary kinetics (O2P) and exercise performance. However, the effects of a moderate-intensity training associated with BFR on a subsequent high-intensity exercise on O2P and cardiac output (QT) kinetics, exercise tolerance, and efficiency remain unknown.This prospective physiologic study was performed at the Exercise Physiology Lab, University of Brasilia. Ten healthy females (mean ±â€ŠSD values: age = 21.3 ±â€Š2.2 years; height = 1.6 ±â€Š0.07 m, and weight = 55.6 ±â€Š8.8 kg) underwent moderate-intensity training associated with or without BFR for 6 minutes prior to a maximal high-intensity exercise bout. O2P, heart rate, and QT kinetics and gross efficiency were obtained during the high-intensity constant workload exercise test.No differences were observed in O2P, heart rate, and QT kinetics in the subsequent high-intensity exercise following BFR training. However, exercise tolerance and gross efficiency were significantly greater after BFR (220 ±â€Š45 vs 136 ±â€Š30 seconds; P < .05, and 32.8 ±â€Š6.3 vs 27.1 ±â€Š5.4%; P < .05, respectively), which also resulted in lower oxygen cost (1382 ±â€Š227 vs 1695 ±â€Š305 mL min-1).We concluded that moderate-intensity BFR training implemented prior to a high-intensity protocol did not accelerate subsequent O2P and QT kinetics, but it has the potential to improve both exercise tolerance and work efficiency at high workloads.