High-intensity interval training for health benefits and care of cardiac diseases——The key to an efficient exercise protocol

Aerobic capacity, which is expressed as peak oxygen consumption (VO2peak), is well-known to be an independent predictor of all-cause mortality and cardiovascular prognosis. This is true even for people with various coronary risk factors and cardiovascular diseases. Although exercise training is the best method to improve VO2peak, the guidelines of most academic societies recommend 150 or 75 min of moderate- or vigorous- intensity physical activities, respectively, every week to gain health benefits. For general health and primary and secondary cardiovascular prevention, high-intensity interval training (HIIT) has been recognized as an efficient exercise protocol with short exercise sessions. Given the availability of the numerous HIIT protocols, which can be classified into aerobic HIIT and anaerobic HIIT [usually called sprint interval training (SIT)], professionals in health-related fields, including primary physicians and cardiologists, may find it confusing when trying to select an appropriate protocol for their patients. This review describes the classifications of aerobic HIIT and SIT, and their differences in terms of effects, target subjects, adaptability, working mechanisms, and safety. Understanding the HIIT protocols and adopting the correct type for each subject would lead to better improvements in VO2peak with higher adherence and less risk.

Femoral neck stress fracture and medial tibial stress syndrome following high intensity interval training: A case report and review of literature

BACKGROUND Femoral and tibial stress injuries are commonly found in long distance running athletes.Stress fractures have rarely been reported in athletes performing high intensity interval training(HIIT)exercise.The objective of this study was to report a case of a patient who presented with medial tibial stress syndrome and femoral neck stress fracture after performing HIIT exercises.CASE SUMMARY A 26 year old female presented with bilateral medial tibial pain.She had been performing HIIT exercise for 45 min,five times weekly,for a seven month period.Her tibial pain was gradual in onset,and was now severe and worse on exercise,despite six weeks of rest.Magnetic resonance imaging(MRI)revealed bilateral medial tibial stress syndrome.As she was taking norethisterone for birth control,a dual energy X-ray absorbitometry scan was performed which demonstrated normal bone mineral density of her lumbar spine and femoral neck.She was managed conservatively with analgesia and physiotherapy,but continued to exercise against medical advice.She presented again six months later with severe right hip pain.MRI of her right hip demonstrated an incomplete stress fracture of her subtrochanteric region.Her symptoms resolved with strict rest and physiotherapy.CONCLUSION HIIT may cause stress injury of the tibia and femur in young individuals.

Health Promotion in Cardiac Rehabilitation Patients through the Use of a High-Intensity Interval Training Protocol

According to the American Heart Association’s (AHA) recent statistical update, over 2150 Americans die each day from cardiovascular disease (CVD), which equals approximately 1 death every 40 seconds;many of which were under the age of 65 years old [1]. In 2009, 386,324 people, 1 in 6 Americans, died as a result of coronary artery disease (CAD) alone [1]. They also estimate 150,000 people have “silent” heart attacks each year [1]. Even though the number of cardiovascular disease deaths has declined in the last 10 years, they still accounted for 32.3% of American deaths [1]. As a result, the AHA updated their 2020 goals to improve the nation’s cardiovascular health by 20% [1]. One of these methods is through the use of cardiac rehabilitation. Cardiac rehabilitation (CR) is a health promotion strategy to help return cardiac patients to their previous level of functioning, increase health, decrease comorbidities and promote education and lifestyle change. For select patients, another alternative exercise plan may exist to gain even better results. High intensity interval training (HIIT) has shown positive training results for athletes and many studies show that it may also be an effective exercise modality for many cardiac patients instead of the traditional circuit training method. This article will review current literature on the effects of HIIT on CR patients as well as a sample HIIT protocol for instituting this treatment with appropriate patients.

Extremely low-volume, high-intensity interval training improves exercise capacity and increases mitochondrial protein content in human skeletal muscle

Purpose: The purpose of the present study was to evaluate whole-muscle content of several proteins involved in the regulation of skeletal muscle mitochondrial protein content and anaerobic capacity following 4 weeks of extremely low-volume high-intensity interval training (HIT). Methods: Young, healthy, recreationally active adult males (n = 8) trained 4 times a week for 4 weeks on a cycle ergometer. Each session involved 4 min of total exercise comprised of eight 20 s intervals at ~170% of peak aerobic power separated by 10 s rest. Muscle biopsies were taken prior to (pre) and ~72 hrs post-training (post). Par- ticipants completed an incremental peak oxygen up- take (VO2peak) test and a Wingate test pre-, mid-, and post-training. Results: VO2peak was elevated (p p < 0.05) and post-training (pre: 40.5 ± 3.8 ml·kg-1·min-1, mid: 43.4 ± 2.5 ml·kg-1·min-1, post-: 47.2 ± 2.9 ml·kg-1·min-1). Wingate mean power also increased with training (pre-: 701.0 ± 73.0 W, mid-: 745.5 ± 73.3 W, post-: 786.8 ± 80.0 W). While maximal citrate synthase activity was unchanged, protein expression of the mitochondrial protein cytochrome c oxidase (COX) subunit I (+27%;p p p = 0.08) increased. Increases (p α (+19%), and nuclear PGC-1α (+46%) were also observed after 4 weeks of HIT. No changes were observed in the whole-muscle contents of PDHe1a, PDK4, SIRT1, mTOR, S6K1, MCT1, or PFK protein. Conclusions: These results demonstrate that several mitochondrial protein (but not citrate synthase activity), PGC-1α protein content, and exercise capacity can be improved in only 4 min of total training time per day, 4 days per wk using HIT cycle training.

Effectiveness of high intensity interval training on cardiorespiratory fitness and endothelial function in type 2 diabetes:A systematic review

BACKGROUND Type 2 diabetes mellitus(T2DM)is a chronic metabolic syndrome characterized by insulin resistance and hyperglycemia that may lead to endothelial dysfunction,reduced functional capacity and exercise intolerance.Regular aerobic exercise has been promoted as the most beneficial non-pharmacological treatment of cardiovascular diseases.High intensity interval training(HIIT)seems to be superior than moderate-intensity continuous training(MICT)in cardiovascular diseases by improving brachial artery flow-mediated dilation(FMD)and cardiorespiratory fitness to a greater extent.However,the beneficial effects of HIIT in patients with T2DM still remain under investigation and number of studies is limited.AIM To evaluate the effectiveness of high intensity interval training on cardiorespiratory fitness and endothelial function in patients with T2DM.METHODS We performed a search on PubMed,PEDro and CINAHL databases,selecting papers published between December 2012 and December 2022 and identified published randomized controlled trials(RCTs)in the English language that included community or outpatient exercise training programs in patients with T2DM.RCTs were assessed for methodological rigor and risk of bias via the Physiotherapy Evidence Database(PEDro).The primary outcome was peak VO_(2 ) and the secondary outcome was endothelial function assessed either by FMD or other indices of microcirculation.RESULTS Twelve studies were included in our systematic review.The 12 RCTs resulted in 661 participants in total.HIIT was performed in 310 patients(46.8%),MICT to 271 and the rest 80 belonged to the control group.Peak VO_(2 ) increased in 10 out of 12 studies after HIIT.Ten studies compared HIIT with other exercise regimens(MICT or strength endurance)and 4 of them demonstrated additional beneficial effects of HIIT over MICT or other exercise regimens.Moreover,4 studies explored the effects of HIIT on endothelial function and FMD in T2DM patients.In 2 of them,HIIT further improved endothelial function compared to MICT and/or the control group while in the rest 2 studies no differences between HIIT and MICT were observed.CONCLUSION Regular aerobic exercise training has beneficial effects on cardiorespiratory fitness and endothelial function in T2DM patients.HIIT may be superior by improving these parameters to a greater extent than MICT.

Running slow or running fast;that is the question:The merits of high-intensity interval training

In a recent issue of the Journal of Sport and Health Science,García-Pinillos et al.~1 reviewed evidence on the effects of highintensity intermittent training(interval training)(HIIT)on muscular and performance adaptations in recreational runners.

The Comparison of the Effects of Two Types of High Intensity Interval Training （HILT） on Body Mass and Physiological Indexes in Inactive Female Students

The aim of this study was to compare the effects of two types of high intensity interval training （HIIT） on body mass and physiological indexes in inactive female students. 27 inactive female students （mean age 24.81 ±0.66 yr, height 162.09 ±0.67 cm, weight 59.41 ±0.33 kg） were voluntarily selected and randomly assigned to three groups （each group = 9 subjects） of high intensity interval training （type I）, high intensity interval training （type 2） and control. HIIT （type 1） （8 seconds of sprint running and 12 seconds of active recovery） was performed for 4 weeks, 3 sessions per week, 6-9 min. per session with above 90% maxHR. HIlT （type 2） （40-m shuttle run test with maximum speed） was performed with above 90% max HR while the control group did not participate in any training. Data analysis with dependent t test showed that HIIT （type 1） and HIlT （type 2） significantly increased VO2max while they decreased fat percentage and BMI. The intergroup data were analyzed by one-way ANOVA at P 〈 0.05. The results showed a significant difference among HIlT （type 1）, HIIT （type 2） and control groups in VO2max, BMI and fat percentage.

Effects of High-Intensity Intermittent Training on Metabolic Parameters and Irisin Levels in High-Fat-Fed Rats

Objective:To investigate the effects of high-intensity intermittent training(HIIT)on preventing significant weight gain and provide scientific theoretical support and practical guidance for reducing the occurrence of obesity.Methods:Twenty-four Sprague-Dawley rats were randomly divided into four groups:the control sedentary group(CS),the high-fat sedentary group(HS),the high-fat continuous exercise group(HE),and the high-fat intermittent exercise group(HI).The HE and HI groups underwent five days of continuous low-intensity exercise and eight weeks of high-intensity intermittent exercise.Weekly monitoring included measurements of food intake and body weight.An automatic biochemical analyzer was used to assess blood lipid and glucose levels,while ELISA kits measured serum insulin and irisin content.H&E staining was used to observe adipocyte size.Results:In the HS group,body weight,blood lipid levels,blood glucose levels,and adipocyte size significantly increased,while the QUICKI index decreased.In the HI group,body weight,blood lipid levels,blood glucose levels,and adipocyte size decreased,and the QUICKI index increased.The effects of high-intensity intermittent exercise were superior to those of continuous low-intensity exercise.In the HI group,serum irisin levels did not change significantly after exercise,while in the HE group,there was a slight upward trend in irisin levels.Conclusion:A high-fat diet induced abnormal metabolism in rats.HIIT effectively prevents metabolic abnormalities induced by a high-fat diet,and its effects are more pronounced than those of low-intensity exercise.HIIT stimulates the secretion of blood irisin,affecting secretion levels,and may represent a novel mechanism for maintaining metabolic homeostasis.This has important implications for controlling significant weight gain.

High-Intensity Interval Training and Diabetes Mellitus

Background: Diabetes mellitus often develops on the background of insulin resistance. High-intensity interval training (HIIT) is included in the treatment of diabetes mellitus since it increases the sensitivity of tissues to insulin. Objective: This paper aimed to review published articles on the effects of HIIT on insulin resistance in diabetic patients. Method: A narrative literature review was undertaken. This review provides evidence from human studies, which highlights the beneficial effects of HIIT in both T1DM and T2DM patients. Conclusion: HIIT is generally safe and effective for people with diabetes mellitus and warrants further exploration.

High-Intensity Interval Training v/s Steady-State Cardio in Rehabilitation of Neurological Patients

Neuropathy is nerve damage that can cause chronic neuropathic pain, which is challenging to cure and has a significant financial burden. Exercise therapies, including High-Intensity Interval Training (HIIT) and steady-state cardio, are being explored as potential treatments for neuropathic pain. This systematic review compares the effectiveness of HIIT and steady-state cardio for improving function in neurological patients. This article provides an overview of the systematic review conducted on the effects of exercise on neuropathic patients, with a focus on high-intensity interval training (HIIT) and steady-state cardio. The authors conducted a comprehensive search of various databases, identified relevant studies based on predetermined inclusion criteria, and used the EPPI automation application to process the data. The final selection of studies was based on validity and relevance, with redundant articles removed. The article reviews four studies that compare high-intensity interval training (HIIT) to moderate-intensity continuous training (MICT) on various health outcomes. The studies found that HIIT can improve aerobic fitness, cerebral blood flow, and brain function in stroke patients;lower diastolic blood pressure more than MICT and improve insulin sensitivity and skeletal muscle mitochondrial content in obese individuals, potentially helping with the prevention and management of type 2 diabetes. In people with multiple sclerosis, acute exercise can decrease the plasma neurofilament light chain while increasing the flow of the kynurenine pathway. The available clinical and preclinical data suggest that further study on high-intensity interval training (HIIT) and its potential to alleviate neuropathic pain is justified. Randomized controlled trials are needed to investigate the type, intensity, frequency, and duration of exercise, which could lead to consensus and specific HIIT-based advice for patients with neuropathies.

How does high-intensity intermittent training affect recreational endurance runners? Acute and chronic adaptations: A systematic review

Objective: This systematic review aimed to critically analyze the literature to determine how high-intensity intermittent training(HIIT) affects recreational endurance runners in the short-and long-term.Methods: Electronic databases were searched for literature dating from January 2000 to October 2015. The search was conducted using the key words "high-intensity intermittent training" or "high-intensity interval exercise" or "interval running" or "sprint interval training" and "endurance runners" or "long distance runners". A systematic approach was used to evaluate the 783 articles identified for initial review. Studies were included if they investigated HIIT in recreational endurance runners. The methodological quality of the studies was evaluated using the Physiotherapy Evidence Database(PEDro) scale(for intervention studies) and the modified Downs and Black Quality Index(for cross-sectional studies).Results: Twenty-three studies met the inclusionary criteria for review. The results are presented in 2 parts: cross-sectional(n = 15) and intervention studies(n = 8). In the 15 cross-sectional studies selected, endurance runners performed at least 1 HIIT protocol, and the acute impact on physiological, neuromuscular, metabolic and/or biomechanical variables was assessed. Intervention studies lasted a minimum of 4 weeks, with 10 weeks being the longest intervention period, and included 2 to 4 HIIT sessions per week. Most of these studies combined HIIT sessions with continuous run(CR) sessions; 2 studies' subjects performed HIIT exclusively.Conclusion: HIIT-based running plans(2 to 3 HIIT sessions per week, combining HIIT and CR runs) show athletic performance improvements in endurance runners by improving maximal oxygen uptake and running economy along with muscular and metabolic adaptations. To maximize the adaptations to training, both HIIT and CR must be part of training programs for endurance runners.

Control method of unfavorable speed interval for high-speed trains

In tests on dynamic performance of high-speed trains, it is found that there is an unfavorable speed interval for some vehicles, which would he harmful to the daily operation of the vehicle. By analyzing the relationship of vibration frequencies of the vehicle and its running speed, this paper finds that the unfavorable speed interval is caused by the vibration superposition of the natural frequency of the vehicle system with the frequency of external excitation. Taking some electric multiple units （EMUs） as examples, we proposed an approach to obtaining the unfavorable speed interval of vehicles. By analyzing the relation between vibration frequencies and the running speed of the vehicle, the natural frequencies of the vehicle system and the external excitations are distinguished. In the end, we suggest some measures to minimize the negative influences of the unfavorable speed interval, such as shifting frequency, reducing or eliminating external excitation.

Suppressive effects of exercise-conditioned serum on cancer cells:A narrative review of the influence of exercise mode,volume,and intensity

Cancer is a major cause of morbidity and mortality worldwide,and the incidence is increasing,highlighting the need for effective strategies to treat this disease.Exercise has emerged as fundamental therapeutic medicine in the management of cancer,associated with a lower risk of recur-rence and increased survival.Several avenues of research demonstrate reduction in growth,proliferation,and increased apoptosis of cancer cells,including breast,prostate,colorectal,and lung cancer,when cultured by serum collected after exercise in vitro(i.e.,the cultivation of cancer cell lines in an experimental setting,which simplifies the biological system and provides mechanistic insight into cell responses).The underlying mechanisms of exercise-induced cancer suppressive effects may be attributed to the alteration in circulating factors,such as skeletal muscle-induced cytokines(i.e.,myokines)and hormones.However,exercise-induced tumor suppressive effects and detailed information about training interventions are not well investigated,constraining more precise application of exercise medicine within clinical oncology.To date,it remains unclear what role different training modes(i.e.,resistance and aerobic training)as well as volume and intensity have on exercise-condi-tioned serum and its effects on cancer cells.Nevertheless,the available evidence is that a single bout of aerobic training at moderate to vigorous intensity has cancer suppressive effects,while for chronic training interventions,exercise volume appears to be an influential candidate driving cancer inhibitory effects regardless of training mode.Insights for future research investigating training modes,volume and intensity are provided to further our understanding of the effects of exercise-conditioned serum on cancer cells.

Producing High Intense Attosecond Pulse Train by Interaction of Three-Color Pulse and Overdense Plasma

Amplifying the attosecond pulse by the chirp pulse amplification method is impossible. Furthermore, the intensity of attosecond pulse is low in the interaction of laser pulse and underdense plasma. This motivates us to propose using a multi-color pulse to produce the high intense attosecond pulse. In the present study, the relativistic interaction of a three-color linearly-polarized laser-pulse with highly overdense plasma is studied. We show that the combination of ω1, ω2 and ω3 frequencies decreases the instance full width at half maximum reflected attosecond pulse train from the overdense plasma surface. Moreover, we show that the three-color pulse increases the intensity of generated harmonics, which is explained by the relativistic oscillating mirror model. The obtained results demonstrate that if the three-color laser pulse interacts with overdense plasma, it will enhance two orders of magnitude of intensity of ultra short attosecond pulses in comparison with monochromatic pulse.

High intensity interval training and molecular adaptive response of skeletal muscle

Increased cardiovascular fitness,VO_(2max),is associated with enhanced endurance capacity and a decreased rate of mortality.High intensity interval training(HIIT)is one of the best methods to increase VO_(2max)and endurance capacity for top athletes and for the general public as well.Because of the high intensity of this type of training,the adaptive response is not restricted to Type I fibers,as found for moderate intensity exercise of long duration.Even with a short exercise duration,HIIT can induce activation of AMPK,PGC-1α,SIRT1 and ROS pathway as well as by the modulation of Ca^(2+)homeostasis,leading to enhanced mitochondrial biogenesis,and angiogenesis.The present review summarizes the current knowledge of the adaptive response of HIIT.

Exercise training in heart transplantation

Heart transplantation remains the gold standard in the treatment of end-stage heart failure(HF).Heart transplantation patients present lower exercise capacity due to cardiovascular and musculoskeletal alterations leading thus to poor quality of life and reduction in the ability of daily self-service.Impaired vascular function and diastolic dysfunction cause lower cardiac output while decreased skeletal muscle oxidative fibers,enzymes and capillarity cause arteriovenous oxygen difference,leading thus to decreased peak oxygen uptake in heart transplant recipients.Exercise training improves exercise capacity,cardiac and vascular endothelial function in heart transplant recipients.Pre-rehabilitation regular aerobic or combined exercise is beneficial for patients with end-stage HF awaiting heart transplantation in order to maintain a higher fitness level and reduce complications afterwards like intensive care unit acquired weakness or cardiac cachexia.All hospitalized patients after heart transplantation should be referred to early mobilization of skeletal muscles through kinesiotherapy of the upper and lower limbs and respiratory physiotherapy in order to prevent infections of the respiratory system prior to hospital discharge.Moreover,all heart transplant recipients after hospital discharge who have not already participated in an early cardiac rehabilitation program should be referred to a rehabilitation center by their health care provider.Although high intensity interval training seems to have more benefits than moderate intensity continuous training,especially in stable transplant patients,individualized training based on the abilities and needs of each patient still remains the most appropriate approach.Cardiac rehabilitation appears to be safe in heart transplant patients.However,long-term follow-up data is incomplete and,therefore,further high quality and adequately-powered studies are needed to demonstrate the long-term benefits of exercise training in this population.

Tremendous Improvement of the Functional Capacity in Patient with Chronic Heart Failure after 12-Weeks of Exercise Training Program

Cardiac rehabilitation is recommended for patients with chronic heart failure (CHF) with preserved, or reduced left ventricular ejection fraction (LVEF). A cardiac rehabilitation program generally includes physical exercise, diet counseling, educational classes on lifestyle changes, and disease management as well as psychosocial support for patients and their families. Exercise training is a core component of the comprehensive cardiac rehabilitation program and is strongly recommended in combination with pharmacological treatment to patients with CHF, due to cardiorespiratory, metabolic, and autonomic cardiac response. Exercise-based cardiac rehabilitation affects positively functional capacity, exercise tolerance, and quality of life in CHF patients. The physical inactivity rate in Arabian Peninsula countries is extremely high, and exercise training of habitually physically inactive individuals should result in marked improvements of physical capacity. We present a case that demonstrates such a significant improvement in the physical capacity of a patient with CHF and a review of literature.

High intensity resistance training as intervention method to knee osteoarthritis

High intensity resistance training(HI-RT)is a treatment option for Knee Osteoarthritis(KOA).Isotonic machines(leg press,leg extension)are utilized for standardization and reproducibility reasons,but the load used during the protocol is often low,considering that elder people usually have low strength levels,training so with high in-tensities calculated on low loads.The physiological response of an elder woman trained with high loads on a free weight exercise,the regular barbell deadlift,with a 1 Repetition Maximum(1RM)of 100 kg,can be appreciated in this report,so that for the first time we can see the effect of a one year of high intensity resistance training program on a powerlifting exercise on a 72 year-old woman with KOA.A Western Ontario and McMaster Uni-versities Arthritis Index(WOMAC)questionnaire was administered before starting the training program(T0)and after 1 year of training,as long as a control RX,to evaluate the effect of HI-RT on joint functionality and quality of life.

高压氧可消除高强度间歇冲击微周期训练中的运动性疲劳

背景:高压氧作为新兴的疲劳消除手段之一,在体育领域中得到越来越多的重视和应用。高压氧干预对高强度间歇冲击微周期训练疲劳消除的研究较少。目的:探究高压氧干预对高强度间歇冲击微周期训练运动性疲劳消除效果的影响,并从血液生化指标和代谢组学方面进行相应机制研究。方法:在首都体育学院招募20名男性大学生,随机分为对照组(n=10)和高压氧组(n=10),均进行高强度间歇冲击微周期训练,为期2周,共12次,具体训练方案为先以50%HR_(max)的强度热身10 min,再以90%-95%HR_(max)强度蹬车4 min,重复5组,组间休息2.5 min,最后再进行50%HR_(max)强度蹬车30 min。对照组受试者训练后自然恢复,高压氧组受试者训练后进行高压氧恢复,每次干预60 min,压力为131.722 kPa。在试验前、试验中期、试验后1 d和试验后3 d采集血液分析生化指标及代谢组学指标,并进行主观感觉疲劳量表评分,其中氧化应激指标与疲劳监控指标进行Pearson相关性分析。结果与结论:①运动性疲劳指标变化:与训练前相比,对照组训练后血尿酸、肌酸激酶、白细胞介素6和主观感觉疲劳量表评分均有不同程度的上调,而高压氧组在高压氧干预后血尿酸、肌酸激酶、白细胞介素6和主观感觉疲劳量表评分变化不大;组间相比,对照组试验后1 d血尿酸、肌酸激酶和白细胞介素6水平显著高于高压氧组;②氧化应激指标变化:与训练前相比,对照组训练后超氧化物歧化酶活性降低、丙二醛水平升高,而高压氧组在高压氧干预后超氧化物歧化酶活性升高、丙二醛水平降低;③超氧化物歧化酶与血尿酸、白细胞介素6和主观感觉疲劳量表评分呈负相关;丙二醛与白细胞介素6和主观感觉疲劳量表评分呈正相关;④代谢组学指标变化:显著变化的代谢通路是花生四烯酸代谢和氧化磷酸化代谢,富集通路上差异代谢物质有花生四烯酸、前列腺素D2、白三烯D4等。结果表明,高强度间歇冲击微周期训练导致机体发生氧化应激,促进了运动性疲劳的产生;高压氧可以一定程度改善氧化应激水平,以及引起花生四烯酸代谢和氧化磷酸化代谢,从而减少氧化损伤,调节炎症反应,促进组织修复和运动性疲劳消除。

Blood flow restriction during the resting periods of high-intensity resistance training does not alter performance but decreases MIR-1 and MIR-133A levels in human skeletal muscle

Blood flow restriction(BFR)during exercise bouts has been used to induce hypertrophy of skeletal muscle,even with low loads.However,the effects of BFR during the rest periods between sets are not known.We have tested the hypothesis that BFR during rest periods between sets of high-intensity resistance training would enhance performance.Twenty-two young adult male university students were recruited for the current study,with n=11 assigned to BFR and n=11 to a control group.The results revealed that four weeks training at 70%of 1 RM,five sets and 10 repetitions,three times a week with and without BFR,resulted in similar progress in maximal strength and in the number of maximal repetitions.The miR-1 and miR-133a decreased significantly in the vastus lateralis muscle of BFR group compared to the group without BFR,while no significant differences in the levels of miR133b,miR206,miR486,and miR499 were found between groups.In conclusion,it seems that BFR restrictions during rest periods of high-intensity resistance training,do not provide benefit for enhanced performance after a four-week training program.However,BFR-induced downregulation of miR-1 and miR-133a might cause different adaptive responses of skeletal muscle to high intensity resistance training.