Ischemia-Reperfusion Intervention: From Enhancements in Exercise Performance to Accelerated Performance Recovery-A Systematic Review and Meta-Analysis

Blood flow restriction as a post-exercise recovery strategy: A systematic review of the current status of the literature

The aim of this study was to systematically review the current literature on blood flow restriction (BFR) as a post-exercise recovery strategy. Experimental studies investigating the effect of BFR on recovery after exercise were included. Only studies meeting the following inclusion criteria were selected: (a) studies investigating about BFR as a post-exercise recovery strategy in athletes and healthy individuals; (b) the full text being available in English; (c) experimental research study design. Studies that exclusively analyzed BFR as a recovery strategy during the exercise (e.g., recovery strategy between bouts of exercise) were excluded. A literature review was conducted on the PubMed, Cochrane, and Web of Science electronic databases up until May 7th, 2023. The main findings were that (i) 9 studies investigated passive BFR as a post-exercise recovery strategy, which shows a significant lack of research in both team and individual sports (especially in female populations), and only 2 studies used active BFR protocols; (ii) although a high quality range of studies was observed, there were methodological limitations such as BFR interventions that were usually conducted after fatiguing protocols or fitness tests, which may not represent the real exercise (e.g., a sprint session of 6 sets of 50 m may induce muscle damage but it does not represent the demands of a team sport like rugby or soccer); (iii) there is a lack of consistency in BFR protocols (e.g., number of cycles or duration of the occlusion-reperfusion periods) for recovery; (iv) some studies showed beneficial effects while others found no positive or detrimental effects of BFR as a post-exercise recovery strategy in comparison with the control/SHAM group. In conclusion, only 11 studies investigated BFR as a post-exercise recovery strategy and there is not any significant amount of evidence in team or individual sports (especially in female populations). BFR could be a potential post-exercise recovery strategy, but practitioners should use caution when applying this method of recovery for their athletes and clients. In addition, it would be of interest for high performance-related practitioners to have a better understanding of the benefits of BFR interventions combined with either active or passive forms of exercise as a post-exercise recovery strategy.

Blood Flow Restricted Electrical Stimulations to Prevent or Attenuate Symptoms of Muscle Damage

The objective of this study was to determine if performing electrical stimulations (E-STIM) under blood flow restriction (BFR) would result in a greater protective effect against symptoms of muscle damage. 18 individuals (9 females) completed a damaging bout of exercise followed by a low frequency E-STIM treatment protocol on both arms, one of which was completed under BFR. The treatment protocol was then repeated 24-hours post-exercise. There were main effects of time for muscle thickness (pre: 3.5 cm; 48 h post: 3.8 cm; BF10 = 88.476), discomfort (pre: 0.0 au; 48 h post: 4.2 au; BF10 = 241.996), and isometric strength (pre: 278 N; 48 h post: 232 N; BF10 = 10,289.894) which all changed as a result of the damaging exercise protocol, but there were no differences between conditions [all Bayes Factors (BF10) < 0.28]. The effectiveness of low frequency E-STIM for preventing the onset of exercise-induced muscle damage would not appear to be enhanced if performed under BFR.

Attenuation of Neuromuscular Fatigue by Ischemic Preconditioning with Moderate Cuff Pressure is Not Related to Muscle Oxygen Saturation in Men

Ischemic preconditioning (IPC) has been an excellent strategy for enhancing sports performance recovery, although there is still no consensus on the ideal protocol. Thus, this study aimed to evaluate the effects of IPC with different cuff pressures (low pressure, medium pressure, and high pressure) on the attenuation of neuromuscular fatigue after an isometric test protocol. And to verify whether this improvement was related to muscle oxygen saturation during the test protocol. Thirty males (18-35 years old) with experience in resistance training were allocated to three different groups: low pressure (20 mmHg), medium pressure (100 mmHg), and high pressure (190 mmHg). The individual occlusion pressure of each participant was identified using ultrasound. Each participant performed two test protocols (8 maximal isometric contractions lasting 20-s with a 10-s rest interval) in an extension chair; after the first test protocol, the participant received the IPC intervention with a low, medium, or high cuff pressure or received the noncuff intervention (randomized order). Only the medium-pressure group showed a smaller decrease in mean force change compared to the no-cuff condition (-4.40% vs. -13.10%, p=0.01, respectively), and the low- and high-pressure groups did not exhibit significant pressure differences (IPC vs. noncuff: -8.40% vs. -13.10%, p=0.11 and -9.10% vs. -14.70%, p=0.12, respectively). Muscle oxygen saturation across test protocols showed no significant differences in all IPC conditions (p>0.05). Although, IPC with medium pressure was effective at optimizing the recovery of neuromuscular performance, this improvement is not related to an increase in muscle oxygen saturation during exercise.

Exercise training and experimental myocardial ischemia and reperfusion: A systematic review and meta-analysis

Background

Despite the success of interventional coronary reperfusion strategies, morbidity and mortality from acute myocardial infarction are still substantial. Physical exercise is a well-recognized effective non-pharmacological therapy for cardiovascular diseases. Therefore, the objective of this systematic review was to analyze studies in animal models of ischemia-reperfusion in association with physical exercise protocols.

Search strategy

Articles published on the topic over a 13-year period (2010-2022) were searched in two databases (PubMed and Google Scholar) using the keywords exercise training, ischemia/reperfusion or ischemia reperfusion injury. Meta-analysis and quality assessment of the studies were performed using the Review Manager 5.3 program.

Results

From the 238 articles retrieved from PubMed and 200 from Google Scholar, after screening and eligibility assessment, 26 articles were included in the systematic review and meta-analysis. For meta-analysis comparing the group of previously exercised animals with the non-exercised animals and then submitted to ischemia-reperfusion, the infarct size was significantly decreased by exercise (p < 0.00001). In addition, the group exercised had increased heart-to-body weight ratio (p < 0.00001) and improved ejection fraction as measured by echocardiography (p < 0.0004) in comparison to non-exercised animals.

Conclusion

We concluded that the animal models of ischemia-reperfusion indicates that exercise reduce infarct size and preserve ejection fraction, associated with beneficial myocardial remodeling.

Ischemic preconditioning and exercise performance: are the psychophysiological responses underestimated?

The findings of the ischemic preconditioning (IPC) on exercise performance are mixed regarding types of exercise, protocols and participants' training status. Additionally, studies comparing IPC with sham (i.e., low-pressure cuff) and/or control (i.e., no cuff) interventions are contentious. While studies comparing IPC versus a control group generally show an IPC significant effect on performance, sham interventions show the same performance improvement. Thus, the controversy over IPC ergogenic effect may be due to limited discussion on the psychophysiological mechanisms underlying cuff maneuvers. Psychophysiology is the study of the interrelationships between mind, body and behavior, and mental processes are the result of the architecture of the nervous system and voluntary exercise is a behavior controlled by the central command modulated by sensory inputs. Therefore, this narrative review aims to associate potential IPC-induced positive effects on performance with sensorimotor pathways (e.g., sham influencing bidirectional body-brain integration), hemodynamic and metabolic changes (i.e., blood flow occlusion reperfusion cycles). Overall, IPC and sham-induced mechanisms on exercise performance may be due to a bidirectional body-brain integration of muscle sensory feedback to the central command resulting in delayed time to exhaustion, alterations on perceptions and behavior. Additionally, hemodynamic responses and higher muscle oxygen extraction may justify the benefits of IPC on muscle contractile function.

Effect of Ischemic Preconditioning on Acute Recovery in Elite Judo Athletes: A Randomized, Single-Blind, Crossover Trial

PURPOSE

The ischemic preconditioning (IPC) method has been shown to aid the recovery processes; however, no studies have been done to assess its acute recovery use in judo. This study aimed to examine IPC of lower limbs effects on recovery after a judo-specific performance in highly trained male judokas and its applicability during a competition day.

METHODS

A single-blind, placebo-randomized crossover study was carried out on a sample of 13 elite male judo athletes. They undertook measurements of body composition, judo-specific task (Special Judo Fitness Test), jump performance, handgrip strength, lactate, blood pressure, perceived exertion, and delayed-onset muscle soreness. IPC was applied on the legs and inflated 50 mm Hg above the systolic blood pressure for 5 minutes and repeated 3 times for each leg, with 5 minutes of reperfusion. Two-way analysis of variance with repeated measurements was used to determine changes between interventions and measurement times. Paired-sample t test and 1-way repeated-measures analysis of variance was used to determine the difference among measurement times. Statistical significance was set at P < .05.

RESULTS

The IPC intervention resulted in (1) decreased heart rate at 30 and 60 minutes during recovery (P = .002; P = .001), (2) better countermovement jump performance at 60 minutes (P = .05), (3) lower perceived-muscle-soreness scores (P = .006), and (4) maintained handgrip strength compared with placebo.

CONCLUSIONS

The present study revealed that IPC applied to judo athletes following judo-specific exercise resulted in better cardiovascular and neuromuscular recovery and could be a useful tool to enhance recovery during judo competition breaks between preliminaries and final block.

Ischemic Preconditioning Improves Handgrip Strength and Functional Capacity in Active Elderly Women

Background: Aging decreases some capacities in older adults, sarcopenia being one of the common processes that occur and that interfered with strength capacity. The present study aimed to verify the acute effect of IPC on isometric handgrip strength and functional capacity in active elderly women. Methods: In a single-blind, placebo-controlled design, 16 active elderly women (68.1 ± 7.6 years) were randomly performed on three separate occasions a series of tests: (1) alone (control, CON); (2) after IPC (3 cycles of 5-min compression/5-min reperfusion at 15 mmHg above systolic blood pressure, IPC); and (3) after placebo compressions (SHAM). Testing included a handgrip isometric strength test (HIST) and three functional tests (FT): 30 s sit and stand up from a chair (30STS), get up and go time (TUG), and 6 min walk distance test (6MWT). Results: HIST significantly increased in IPC (29.3 ± 6.9 kgf) compared to CON (27.3 ± 7.1 kgf; 7.1% difference; p = 0.01), but not in SHAM (27.7 ± 7.9; 5.5%; p = 0.16). The 30STS increased in IPC (20.1 ± 4.1 repetitions) compared to SHAM (18.5 ± 3.5 repetitions; 8.7%; p = 0.01) and CON (18.5 ± 3.9 repetitions; 8.6%; p = 0.01). TUG was significantly lower in IPC (5.70 ± 1.35 s) compared to SHAM (6.14 ± 1.37 s; −7.2%; p = 0.01), but not CON (5.91 ± 1.45 s; −3.7%; p = 0.24). The 6MWT significantly increased in IPC (611.5 ± 93.8 m) compared to CON (546.1 ± 80.5 m; 12%; p = 0.02), but not in SHAM (598.7 ± 67.6 m; 2.1%; p = 0.85). Conclusions: These data suggest that IPC can promote acute improvements in handgrip strength and functional capacity in active elderly women.

Potential protective effect of hesperidin on hypoxia/reoxygenation-induced hepatocyte injury

Hesperidin (HDN) has been reported to have hydrogen radical- and hydrogen peroxide-removal activities and to serve an antioxidant role in biological systems. However, whether HDN protects hepatocytes (HCs) against hypoxia/reoxygenation (H/R)-induced injury remains unknown. The present study aimed to explore the role of HDN in H/R-induced injury. HCs were isolated and cultured under H/R conditions with or without HDN treatment. HC damage was markedly induced under H/R, as indicated by cell viability, supernatant lactate dehydrogenase levels and alanine aminotransferase levels; however, HDN treatment significantly reversed HC injury. Oxidative stress markers (malondialdehyde, superoxide dismutase, glutathioneand reactive oxygen species) were increased markedly during H/R in HCs; however, this effect was significantly attenuated after exposure to HDN. Compared with those of the control group, the mRNA expression levels of IL-6 and TNF-α in HCs and the concentrations of IL-6 and TNF-α in the supernatants increased significantly following H/R, and HDN significantly ameliorated these effects. Western blotting demonstrated that microtubule-associated protein 1 light chain 3α (MAP1LC3A, also known as LC3) and Beclin-1 protein expression levels increased, while sequestosome 1 levels decreased during H/R following exposure to HDN. The number of GFP-LC3 puncta in HCs following exposure to HDN was increased compared with that observed in HCs without HDN exposure under the H/R conditions after bafilomycin A1 treatment. In summary, the present study demonstrated that HDN attenuated HC oxidative stress and inflammatory responses while enhancing autophagy during H/R. HDN may have a potential protective effect on HCs during H/R-induced injury.