Low-intensity resistance exercise with blood flow restriction and arterial stiffness in humans: A systematic review

Acute impact of autoregulation of applied blood flow restriction pressures on bilateral single-joint upper limb resistance exercise

To investigate the acute effects of 4 sets of autoregulated (AR-BFR) versus non-autoregulated (NAR-BFR) applied pressures during blood flow restriction (BFR) resistance exercise to volitional failure compared with low-load exercise without BFR. A randomized crossover design study was conducted on 32 healthy adults (20.8 ± 2.3 years; 11 females). Outcome measures were as follows: (1) arterial stiffness, (2) peak perceptual responses and likelihood to perform again, and (3) performance. Results: Post-exercise changes in central and brachial diastolic blood pressure were decreased in all groups. Post-exercise supine systolic blood pressure in no-BFR increased (mean difference (MD) = 4 ± 1 mmHg, 95% CI (1-7), p = 0.003, η2 = 0.13). Total repetitions performed and volume workload were similar between BFR conditions but less than no-BFR. AR-BFR reported significantly higher exertion (MD = 0.53 ± 0.2, 95% CI (0.04-1.0), p = 0.03, η2 = 0.19) than other conditions, and induced greater discomfort (MD = 2.50 ± 0.36, 95% CI (1.63-3.37), p < 0.001, η2 = 0.28) than no-BFR. Conclusion: Biceps curl exercise to volitional failure appears to induce negligible arterial stiffness or blood pressure changes regardless of the application of autoregulation, yet autoregulation appears to enhance the perceptual response to BFR exercise compared to NAR-BFR without impacting exercise performance.

Autoregulated and Non-Autoregulated Blood Flow Restriction on Acute Arterial Stiffness

This study aimed to investigate the acute effects of autoregulated and non-autoregulated applied pressures during blood flow restriction resistance exercise to volitional fatigue on indices of arterial stiffness using the Delfi Personalized Tourniquet System. Following a randomized autoregulated or non-autoregulated blood flow restriction familiarization session, 20 physically active adults (23±5 years; 7 females) participated in three randomized treatment-order sessions with autoregulated and non-autoregulated and no blood flow restriction training. Participants performed four sets of dumbbell wall squats to failure using 20% of one repetition maximum. Blood flow restriction was performed with 60% of supine limb occlusion pressure. Testing before and post-session included an ultrasonic scan of the carotid artery, applanation tonometry, and blood pressure acquisition.Carotid-femoral pulse wave velocity increased in the non-autoregulated and no blood flow restriction training groups following exercise while carotid-radial pulse wave velocity increased in the no blood flow restriction training group (all p<0.05). Carotid-femoral pulse wave velocity exhibited an interaction effect between autoregulated and non-autoregulated blood flow restriction in favor of autoregulated blood flow restriction (p<0.05). Autoregulated blood flow restriction training does not influence indices of arterial stiffness while non-autoregulated and no blood flow restriction training increases central stiffness.

Changes in Arterial Stiffness in Response to Blood Flow Restriction Resistance Training: A Narrative Review

Arterial stiffness naturally increases with age and is a known predictor of cardiovascular morbimortality. Blood flow restriction (BFR) training involves decreasing muscle blood flow by applying a strap or a pneumatic cuff during exercise. BFR induces muscle hypertrophy even at low intensities, making it an appealing option for older, untrained individuals. However, BFR use in patients with cardiovascular comorbidities is limited by the increased pressor and chronotropic response observed in hypertensive elderly patients. Furthermore, the impact of BFR on vascular function remains unclear. We conducted a comprehensive literature review according to PRISMA guidelines, summarizing available data on the acute and long-term consequences of BFR training on vascular function. Although evidence is still scarce, it seems that BFR has a mild or neutral long-term impact on arterial stiffness. However, current research shows that BFR can cause an abrupt, albeit transient, increase in PWV and central blood pressure. BFR and, preferably, lower-body BFR, should be prescribed with caution in older populations, especially in hypertensive patients who have an exacerbated muscle metaboreflex pressor response. Longer follow-up studies are required to assess the chronic effect of BFR training on arterial stiffness, especially in elderly patients who are usually unable to tolerate high-intensity resistance exercises.

Acute cardiovascular responses to unilateral bicep curls with blood flow restriction

A consensus on the acute cardiovascular responses to low intensity (LI) resistance exercise (RE) combined with blood flow restriction (BFR) has not yet been reached. This study was designed to compare acute cardiovascular responses to a single bout of LIRE, high intensity (HI) RE, and LIRE with BFR in physically active young males. Participants completed 3 RE sessions in random order, where each session consists of 4 sets of unilateral dumbbell bicep curls. Cardiovascular hemodynamics were measured at baseline and right after each set of RE. Aortic augmentation index (AIx) was significantly higher after set 2,3,4 of RE in LI + BFR session compared to LI session (P < 0.05). Brachial systolic blood pressure (SBP), heart rate (HR), brachial rate pressure product (RPP), and central RPP responses did not differ between LI and LI + BFR sessions (P > 0.05). HI session had a higher central SBP, brachial RPP, central RPP, and aortic AIx compared to LI session after each set of RE (P < 0.05), but not brachial SBP (P > 0.05). Taken together, this study showed that LIRE combined with BFR acutely augmented aortic stiffness, as also observed in HI session, but myocardial oxygen consumption was only higher in HI session when compared to LI session. Thus, although BFR did not exaggerate cardiovascular responses nor cause extra myocardial oxygen consumption, it should be prescribed with caution when control of acute aortic stiffening is necessary during RE.

Effects of blood flow restriction on spine postural control using a robotic platform: A pilot randomized cross-over study

BACKGROUND

Blood flow restriction (BFR) training improves muscle strength and functional outcomes, but the proprioceptive implications of this technique in the rehabilitation field are still unknown.

OBJECTIVE

The present study aimed at assessing the effects of BFR in terms of stabilometric and balance performance.

METHODS

In this pilot randomized cross-over study, healthy young adults were included and randomly assigned to Groups A and B. Both groups underwent a postural assessment with and without wearing a BFR device. Study participants of Group A underwent postural baseline assessment wearing BFR and then removed BFR for further evaluations, whereas subjects in Group B performed the baseline assessment without BFR and then with BFR. Stabilometric and balance performance were assessed by the robotic platform Hunova, the Balance Error Scoring System (BESS), the self-reported perceived balance (7-point Likert scale), and discomfort self-rated assessment. Moreover, the safety profile was recorded.

RESULTS

Fourteen subjects were included and randomly assigned to Group A (n: 7) and Group B (n: 7). Significant differences were shown in balance tests in static conditions performed on the Hunova robot platform in terms of average distance RMS (root-mean-square) with open eyes (OE), anteroposterior (AP) trunk oscillation range with OE, mediolateral (ML) average speed of oscillation with OE, and total excursion AP range with closed eyes (CE) (BFR: 3.44 ± 1.06; without BFR: 2.75 ± 0.72; p= 0.041). Moreover, elastic balance test showed differences in Romberg index (BFR: 0.16 ±0.16; without BFR: 0.09 ± 0.07; p= 0.047). No adverse events were reported.

CONCLUSION

Taken together, our data showed that BFR affects balance performance of healthy subjects. Further studies are needed to better characterize the possible role of BFR treatment in the context of a specific rehabilitation protocol.

Acute Effects of the Interval and Duration of Intermittent Exercise on Arterial Stiffness in Young Men

We proved the hypothesis that intermittent exercise would have a better effect on arterial stiffness by shortening the duration of intervals and increasing the number of bouts. Twenty healthy male college students (20.4 ± 0.4 years) were randomly assigned to a quiet control (CON), 30 min continuous exercise (CE), long-interval intermittent exercise with long intervals (IELL), long-interval intermittent exercise with short intervals (IELS), and short-interval intermittent exercise with short intervals (IESS). The intensity was set to 45% of the heart rate reserve. The brachial-ankle pulse wave (baPWV) was measured at baseline (BL), 0 min post-exercise, 20 min post-exercise, 40 min post-exercise, and 60 min post-exercise. BaPWV changes (⊿baPWV) from the BL in the same tests were used for the analysis. ⊿baPWV did not change significantly in the CON. ⊿baPWV decreased significantly at 0, 20, and 40 min in all exercise tests. ⊿baPWV decreased significantly at 60 min in IELS and IESS. At 60 min, the ⊿baPWV of IELS and IESS was still significantly lower than that of CON and CE, and the ⊿baPWV of IESS was still significantly lower than that of IELS. Hence, shortening the intervals of intermittent exercise and increasing the number of repetitions may enhance the effect of improving arterial stiffness.

Low-to-Moderate-Intensity Resistance Exercise Effectively Improves Arterial Stiffness in Adults: Evidence From Systematic Review, Meta-Analysis, and Meta-Regression Analysis

Background/Purpose: Resistance exercise (RE) is known to improve cardiovascular health, but the role of RE variables on arterial stiffness is inconclusive. In this systematic review and meta-analysis, we investigated the influence of RE and its intensities on arterial stiffness measured as pulse wave velocity (PWV) in young and middle-aged adults. Methods: Web of Science, PubMed/MEDLINE, Scopus, EMBASE, Cochrane Library, ScienceDirect, CINAHL, Wiley Online Library, and Google Scholar were searched for relevant studies. RE trials that reported PWV data, and compared with respective controls were included. The Cochrane Collaboration tool was used to assess the risk of bias. Results: Data were synthesized from a total of 20 studies, involving 981 participants from control (n = 462) and exercise (n = 519) trials. The test for overall effect (pooled outcome) showed RE intervention had no effect on arterial stiffness (SMD = -0.09; 95% CI: -0.32, 0.13; P = 0.42), but risk of heterogeneity (I 2) was 64%. Meta-regression results revealed a significant correlation (P = 0.042) between RE intensity and PWV changes. Consequently, the trials were subgrouped into high-intensity and low-to-moderate-intensity to identify the effective RE intensity. Subgroup analysis showed that low-to-moderate-intensity significantly decreased PWV (SMD = -0.34; 95% CI: -0.51, -0.17; P < 0.0001), while high-intensity had no effect (SMD = 0.24; 95% CI: -0.18, 0.67; P = 0.26). When trials separated into young and middle-aged, low-to-moderate-intensity notably decreased PWV in young (SMD = -0.41; 95% CI: -0.77, -0.04; P = 0.03) and middle-aged adults (SMD = -0.32; 95% CI: -0.51, -0.14; P = 0.0007), whereas high-intensity had no effect in both age groups. Conclusions: Our findings demonstrated that RE intensity is the key variable in improving arterial stiffness. Low-to-moderate-intensity can prescribe as an effective non-pharmacological strategy to treat cardiovascular complications in young and middle-aged adults.

THE THERAPEUTIC EFFECTS OF SPORTS ON ARTERIAL STIFFNESS

ABSTRACT Introduction: Cardiovascular disease has become a significant condition affecting human health. Increased arterial stiffness is a leading stage in the occurrence and development of many cardiovascular diseases. Objective: To observe the effect of different acute exercise programs on arterial stiffness of healthy young people under the same amount of exercise. Methods: We selected 16 healthy boys to conduct a blank control test, continuous exercise test, and intermittent exercise. They were divided into blank schemes. Car plan and running plan. Arterial stiffness was repeatedly measured immediately after exercise and 40 minutes after the end. Results: In the three exercise intervention experiments, the heart-ankle vascular index decreased significantly immediately after exercise. After 60 minutes of rest, the heart-ankle vascular index rebounded. Conclusion: Physical exercise can significantly reduce arterial stiffness. Changing the training intensity in sports with the same target heart rate does not affect arterial stiffness. Level of evidence II; Therapeutic studies - investigation of treatment results.