The impact of high-intensity interval training on vascular function in adults: A systematic review and meta-analysis

Effects of two forms of school-based high-intensity interval training on body fat, blood pressure, and cardiorespiratory fitness in adolescents: randomized control trial with eight-week follow-up-the PEER-HEART study

Introduction

This study examined the effects of 8-week interventions based on two variants of typical exercises, namely, high-intensity interval training (HIIT) and high-intensity plyometric training (HIPT), on body fat (BF%), blood pressure, and cardiorespiratory fitness (CRF). In addition, the sustainability of the effects after another 8 weeks was assessed.

Methods

The project was designed as a randomized controlled trial with eight groups of participants (two variants, two sexes, and two groups (experimental and control)) and was conducted in a school physical education (PE) program. The outcomes analyzed were the BF%, systolic (SBP), diastolic blood pressure (DBP), and CRF expressed in terms of maximum oxygen uptake (VO2max). A total of 307 healthy adolescents participated in this study and were randomly assigned into the two groups. During the 8 weeks, the participants completed two exercise sessions each week with progressively increasing volumes. For the first 2 weeks, the sessions involved four rounds of 20 s of intense effort followed by 10 s of rest; this increased to six rounds during weeks 3-4 and eight rounds during weeks 5-8. The HIPT program was based on plyometric exercises, whereas the HIIT was based on bodyweight resistance exercises.

Results

Multidimensional analysis of variance (ANOVA) indicated a statistically significant second-order interaction (time × variant × group: Ʌ = 0.943, F = 2.20, p < 0.027, η2 pG = 0.057, d = 0.25), confirming the changes in the BF%, SBP, DBP, and VO2max dependent on the type of intervention and group assignment. The ANOVA results revealed significant main and interaction effects for BF%, SBP, and DBP, with time and the HIIT variant as the main contributors (BF%: F = 3.911, p = 0.023, η2 pG = 0.001, d = 0.04 vs. F = 9.900, p < 0.001, η2 pG = 0.001, d = 0.03; SBP: F = 31.801, p < 0.001, η2 pG = 0.012, d = 0.16 vs. F = 8.939, p = 0.003, η 2 pG = 0.026, d = 0.16; DBP: F = 3.470, p = 0.033, η2 pG = 0.002, d = 0.06 vs. F = 4.982, p = 0.026, η2 pG = 0.014, d = 0.12). The second-order interaction for VO2max (time × sex × group: F = 6.960, p = 0.001, η2 pG = 0.003, d = 0.05) indicated that the improvements over time were not related to the training variant. Although these effects were small (low eta values), post hoc tests (all comparisons in post-intervention, p > 0.05) showed that both the HIIT and HIPT groups exhibited beneficial changes compared to controls; however, no statistically significant differences were observed between the experimental and control groups. Furthermore, the observed improvements were maintained through the 8-week follow-up period, as demonstrated by no significant changes between the post-intervention and follow-up measurements (p > 0.05). Discriminant analysis showed that BF% and SBP were the key variables for the two exercise variants in men, with HIPT yielding greater reductions in SBP and HIIT resulting in more pronounced decreases in BF%.

Discussion

In conclusion, both HIIT and HIPT interventions effectively improved health-related parameters, providing valuable enrichment to the PE lessons in schools. These benefits were also sustained for at least 8 weeks post-intervention.

Changes in the reactive hyperemia index after continuous and interval exercise

INTRODUCTION

High-intensity interval exercise (HIIE) is more effective than moderate-intensity interval exercise (MICE) for improving macrovascular function (e.g., flow-mediated dilation), but less is known regarding the effect of HIIE on microvascular function. We used peripheral artery tonometry to measure the reactive hyperemia index (RHI) and examine the acute effects of HIIE and MICE on microvascular function.

METHODS

Ten healthy participants (50% men, age: 26 ± 5 years, mass: 75.6 ± 15.1 kg, height: 170 ± 10 cm, body mass index: 26.0 ± 3.1 kg∙m-2) performed single bouts of HIIE and MICE cycling on separate occasions. The MICE protocol was 20 min at 60% of maximum power output. The HIIE protocol was a 12-min warm up at 50% of maximum power output immediately followed by an 8-min Tabata protocol where participants alternated between cycling at ⩾ 100% max power (20 sec) and rest (10 sec). The RHI was measured before, immediately after, and 1 h after exercise and compared by two-way repeated measures analysis of variance (condition [MICE, HIIE] and time [pre-, post-, and 1-h postexercise]).

RESULTS

Compared to baseline, RHI increased 1 h after MICE only (p = 0.02). Heart rate was higher during MICE at 5 and 10 min (p = 0.02) and higher during HIIE at min 20 (p < 0.01).

CONCLUSION

Within a sample of healthy adults, the RHI was improved 1 h after a single session of MICE but not HIIE. Future research is needed to determine the significance of the differential effects of exercise regimens on the macro- and microvasculature.

Modulation of Vascular Health by Hormonal Contraceptives and Exercise in Young Women: Using the FITT Principles Methodological Framework

Cardiovascular health is governed by responses of the heart and vasculature to stimuli, including exercise and synthetic hormones in hormonal contraception. In this review, we draw similarities between research examining the effects of exercise training and hormonal contraception on vascular health, aligned using FITT principles (frequency, intensity, type, and time) as a methodological framework, and outline future directions for research.

Acute high-intensity interval exercise is superior to moderate-intensity continuous exercise in enhancing endothelial function and its associated biomarkers in sedentary young individuals: the possible involvement of lactate

Objectives

Our study investigated the effects of acute high-intensity interval exercise (HIIE) and moderate-intensity continuous exercise (MICE) on endothelial function and its associated biomarkers in sedentary young individuals.

Methods

Fifteen subjects (10M / 5F; 22 ± 2 years; BMI: 23.07 ± 4.12 kg/m2) participated in a crossover trial including three experimental conditions: HIIE, MICE, and a control session of rest (CON) in random order separated by a 7-day washout period. Endothelial function was assessed using flow-mediated dilation (FMD), mean shear rate (MSR), and circulating levels of blood lactate, VEGF, IGF-1, and irisin.

Results

Both HIIE and MICE significantly enhanced FMD% (both P < 0.001 and P < 0.01, respectively), lactate (both P < 0.001), VEGF (P < 0.001 and P < 0.01, respectively), IGF-1 (both P < 0.001), and irisin (P < 0.001 and P < 0.05, respectively), with a greater extent after HIIE compared to MICE in FMD% (P < 0.001), MSR (P < 0.05), lactate (P < 0.001), VEGF (P < 0.05), and IGF-1 (P < 0.05). Additionally, change (post-pre) in FMD% was positively correlated with changes in MSR, lactate, and VEGF in both HIIE and MICE conditions. Change in MSR was positively associated with changes in lactate and VEGF in both HIIE and MICE conditions. Furthermore, enhancement in lactate was correlated with enhancements in VEGF in both HIIE and MICE conditions.

Conclusions

Acute HIIE is a more effective method than MICE at improving endothelial function in sedentary young individuals and increases in lactate and its mediated VEGF release, attributed to increase in shear rate after exercise, are involved in regulatory mechanisms.

Effects of high-intensity interval training versus moderate-intensity continuous training on vascular function among individuals with overweight and obesity-a systematic review

BACKGROUND

The study aimed to investigate and systematically review the evidence relating to the effects of high-intensity interval training (HIIT) versus moderate-intensity continuous training (MICT) on vascular function such as arterial diameter, arterial stiffness, pulse wave velocity, blood flow, etc. in individuals with overweight and obesity.

METHODS

The entire content of PubMed (MEDLINE), Scopus, SPORT Discus® (via EBSCO host), CINAHL, and Web of Science were searched. Only experimental research studies conducted in adult participants aged ≥18 years, published in English before January 2023 were included.

RESULTS

A total of 5397 studies were reviewed for the title and abstract with 11 studies being included for data extraction. The review resulted in a total of 346 individuals with overweight and obesity with body mass index (BMI) ranging between 25-36 kg/m2. HIIT and MICT intensities resulted in 85%-95% and 60%-70% maximal heart rate (MHR) respectively. Seven out of 11 studies showed some concerns about the overall risk of bias. Six of 11 studies reported improving vascular function following HIIT than MICT.

CONCLUSION

HIIT is a more effective and time-efficient exercise for enhancing vascular functions in individuals with overweight and obesity, leading to improvements in flow-mediated dilation by 3.9% and arterial diameter by 4.8%, compared to MICT.

Effect of eight-week high-intensity interval training versus moderate-intensity continuous training programme on body composition, cardiometabolic risk factors in sedentary adolescents

Objectives

This study aimed to assess and compare the effect of an 8-week high-intensity interval training (HIIT) or moderate-intensity continuous training (MICT) programme on body composition and cardiovascular metabolic outcomes of sedentary adolescents in China.

Methods

Eighteen sedentary normal-weight adolescents (age: 18.5 ± 0.3 years, 11 females) were randomized into three groups. HIIT group protocol consisted of three sessions/week for 8-week of "all out" sprints to reach 85%-95% of HRmax, and MICT group protocol undertook three sessions/week for 8-week of continuous running to reach 65%-75% of HRmax. The control group resumed normal daily activities without any intervention. Blood pressure and body composition were measured, and fasting blood samples were obtained at baseline and 48 h post-trial. Mixed-design ANOVA analysis was employed followed by post hoc t-tests and Bonferroni alpha-correction was used to evaluate interaction, between-group, and within-group differences, respectively.

Results

Results indicated that HIIT and MICT similarly affected body fat mass (p = 0.021, ES = 0.19; p = 0.016, ES = 0.30, respectively), body fat percentage (p = 0.037, ES = 0.17; p = 0.041, ES = 0.28, respectively), visceral fat area (p = 0.001, ES = 0.35; p = 0.003, ES = 0.49, respectively) of body composition. A positive outcome was observed for waist/hip ratio (p = 0.033, ES = 0.43) in HIIT, but not MICT (p = 0.163, ES = 0.33). No significant differences were found between groups for any clinical biomarkers. However, pairwise comparison within the group showed a significant decrease in systolic blood pressure (p = 0.018, ES = 0.84), diastolic blood pressure (p = 0.008, ES = 1.76), and triglyceride (p = 0.004, ES = 1.33) in HIIT, but no significant differences were found in the MICT and Control group.

Conclusion

Both 8-week HIIT and MICT programmes have similar positive effects on reducing body fat mass, fat percentage, and visceral fat area. However, sedentary adolescents may have limited scope to decrease insulin resistance after these 8-week interventions. Notably, the 8-week HIIT intervention was highly effective in increasing cardiometabolic health compared to the MICT. The exercise intensity threshold value and metabolic outcomes of high-intensity interval sprints should be explored further to extend the long-term benefit in this cohort.

Socioeconomic status as a potential mediator of arterial aging in marginalized ethnic and racial groups: current understandings and future directions

Cardiovascular diseases (CVDs) are the leading cause of death in the United States. However, disparities in CVD-related morbidity and mortality exist as marginalized racial and ethnic groups are generally at higher risk for CVDs (Black Americans, Indigenous People, South and Southeast Asians, Native Hawaiians, and Pacific Islanders) and/or development of traditional CVD risk factors (groups above plus Hispanics/Latinos) relative to non-Hispanic Whites (NHW). In this comprehensive review, we outline emerging evidence suggesting these groups experience accelerated arterial dysfunction, including vascular endothelial dysfunction and large elastic artery stiffening, a nontraditional CVD risk factor that may predict risk of CVDs in these groups with advancing age. Adverse exposures to social determinants of health (SDOH), specifically lower socioeconomic status (SES), are exacerbated in most of these groups (except South Asians-higher SES) and may be a potential mediator of accelerated arterial aging. SES negatively influences the ability of marginalized racial and ethnic groups to meet aerobic exercise guidelines, the first-line strategy to improve arterial function, due to increased barriers, such as time and financial constraints, lack of motivation, facility access, and health education, to performing conventional aerobic exercise. Thus, identifying alternative interventions to conventional aerobic exercise that 1) overcome these common barriers and 2) target the biological mechanisms of aging to improve arterial function may be an effective, alternative method to aerobic exercise to ameliorate accelerated arterial aging and reduce CVD risk. Importantly, dedicated efforts are needed to assess these strategies in randomized-controlled clinical trials in these marginalized racial and ethnic groups.

Jumping Interval Training: An Effective Training Method for Enhancing Anaerobic, Aerobic, and Jumping Performances in Aerobic Gymnastics

The aim of this study was to compare the effects of jumping interval training (JIT) and running high-intensity interval training (HIIT) on the aerobic, anaerobic and jumping performances of youth female aerobic gymnasts. A randomized controlled study was conducted over an 8-week period, involving 73 youth female athletes (16.2 ± 1.3 years old) of aerobic gymnastics. The study comprised two experimental groups (JIT and HIIT) and a control group. Participants in the experimental groups engaged in two additional training sessions per week alongside their regular training regimen, while the control group followed their usual training routine. Before and after the intervention period, gymnasts were assessed for their performance in the countermovement jump test (CMJ), the specific aerobic gymnastics anaerobic test (SAGAT) and the 20-m multistage fitness test. Significant interactions time × group were found in SAGAT (p < 0.001; = 0.495), CMJ (p < 0.001; = 0.338) and 20-m multistage fitness test (p < 0.001; = 0.500). The time × group analysis post-intervention revealed significantly lower scores in SAGAT for the control group compared to the JIT (p = 0.003) and HIIT (p = 0.034). Additionally, significantly higher scores were observed for the JIT group in the CMJ test compared to the HIIT (p = 0.020) and control (p = 0.028) groups following the intervention. Finally, the 20 m multistage fitness test post-intervention revealed significantly lower scores for the control group compared to JIT (p < 0.001) and HIIT (p < 0.001). Both JIT and HIIT are recommended training strategies to adopt in aerobic gymnastics for significantly improving the aerobic and anaerobic performances of athletes. However, JIT may be particularly relevant to use as it offers additional benefits in improving vertical jumping performances.

Aerobic exercise interventions for promoting cardiovascular health and mobility after stroke: a systematic review with Bayesian network meta-analysis

OBJECTIVE

To determine the superiority of aerobic exercise (AE) interventions on key outcomes of stroke recovery, including cardiorespiratory fitness (V̇O2peak, primary outcome), systolic blood pressure (SBP) and mobility (6 min Walk Test (6MWT) distance and 10 m Usual Gait Speed) after stroke.

DATA SOURCES

MEDLINE, EMBASE, Web of Science, CINAHL, CENTRAL, SPORTDiscus, PsycINFO and AMED Allied and Complementary Medicine were searched from inception to February 2023.

ELIGIBILITY CRITERIA

Randomised controlled trials were included that compared the effects of any AE interventions (low-intensity, moderate-intensity, high-intensity continuous training (HICT), high-intensity interval training (HIIT)) to no exercise, usual care or other AE interventions in individuals poststroke.

ANALYSES

Systematic review with Bayesian network meta-analysis (NMA) methodology was employed. Surface under the cumulative ranking curve (SUCRA) values were used to rank interventions. The Grading of Recommendations, Assessment, Development and Evaluation minimally contextualised framework for NMA was followed.

RESULTS

There were 28 studies (n=1298) included in the NMA for V̇O2peak, 11 (n=648) for SBP, 28 (n=1494) for 6MWT and 18 (n=775) for the 10 m Usual Gait Speed. The greatest effect on V̇O2peak, 6MWT and 10 m Usual Gait Speed was observed after HIIT and HICT. No differences between interventions were found for SBP. SUCRA values identified HIIT as the superior AE intervention for all outcomes of interest. HIIT was the most effective intervention for improving V̇O2peak (2.9 mL/kg/min (95% credible interval 0.8 to 5.0) moderate certainty) compared with usual care.

CONCLUSION

This NMA suggests that higher-intensity AE is superior to traditional low-intensity to moderate-intensity AE for improving outcomes after stroke.

Vascular-endothelial adaptations following low and high volumes of high-intensity interval training in patients after myocardial infarction

BACKGROUND

Determinants of coronary artery disease, such as endothelial dysfunction and oxidative stress, could be attenuated by high-intensity aerobic interval exercise training (HIIT). However, the volume of this type of training is not well established.

OBJECTIVE

To assess the impact of two volumes of HIIT, low (LV-HIIT, <10 min at high intensity) and high (HV-HIIT, >10 min at high intensity), on vascular-endothelial function in individuals after an acute myocardial infarction (AMI).

MATERIALS AND METHODS

Clinical trial in 80 AMI patients (58.4 ± 8.3 years, 82.5% men) with three study groups: LV-HIIT (n = 28) and HV-HIIT (n = 28) with two sessions per week for 16 weeks and control group (CG, n = 24) with unsupervised physical activity recommendations. Endothelial function (brachial flow-mediated dilation, FMD), atherosclerosis (carotid intima-media thickness ultrasound, cIMT), and levels of oxidized low-density lipoprotein (ox-LDL) as a marker of oxidative stress were determined before and after the intervention period.

RESULTS

After the intervention, in the exercise groups, there was an increase in FMD (LV-HIIT, ↑58.8%; HV-HIIT, ↑94.1%; p < 0.001) concurrently with a decrease in cIMT (LV-HIIT, ↓3.0%; HV-HIIT, ↓3.2%; p = 0.019) and LDLox (LV-HIIT, ↓5.2%; HV-HIIT, ↓8.9%; p < 0.001), with no significant changes in the CG. Furthermore, a significant inverse correlation was observed between ox-LDL and endothelial function related to the volume of HIIT training performed (LV-HIIT: r = -0.376, p = 0.031; HV-HIIT: r = -0.490, p < 0.004), with no significance in the CG (r = 0.021, p = 0.924).

CONCLUSION

In post-AMI patients, HIIT may lead to a volume-dependent enhancement in endothelial function, attributed to a decrease in oxidative stress, with added beneficial effects in reducing vascular wall thickness. An LV-HIIT program, with less than 10 min at high intensity per session, has proven enough efficiency to initiate favorable vascular-endothelial adaptations, potentially reducing cardiovascular risk among patients with coronary artery disease.

TRIAL REGISTRATION

INTERFARCT, ClinicalTrials.gov: NCT02876952.

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 VO2 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 VO2 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.

The Acute and Chronic Effects of Resistance and Aerobic Exercise in Hemostatic Balance: A Brief Review

Hemostatic balance refers to the dynamic balance between blood clot formation (coagulation), blood clot dissolution (fibrinolysis), anticoagulation, and innate immunity. Although regular habitual exercise may lower the incidence of cardiovascular diseases (CVD) by improving an individual’s hemostatic profile at rest and during exertion, vigorous exercise may increase the risk of sudden cardiac death and venous thromboembolism (VTE). This literature review aims to investigate the hemostatic system’s acute and chronic adaptive responses to different types of exercise in healthy and patient populations. Compared to athletes, sedentary healthy individuals demonstrate similar post-exercise responses in platelet function and coagulatory and fibrinolytic potential. However, hemostatic adaptations of patients with chronic diseases in regular training is a promising field. Despite the increased risk of thrombotic events during an acute bout of vigorous exercise, regular exposure to high-intensity exercise might desensitize exercise-induced platelet aggregation, moderate coagulatory parameters, and up-regulate fibrinolytic potential via increasing tissue plasminogen activator (tPA) and decreasing plasminogen activator inhibitor (PAI-1) response. Future research might focus on combining different types of exercise, manipulating each training characteristic (frequency, intensity, time, and volume), or investigating the minimal exercise dosage required to maintain hemostatic balance, especially in patients with various health conditions.

Protective Role of Chronic Exercise Training in Modulating the Impact of Hyperglycemia on Vascular Sensitivity to Ischemia-Reperfusion

Hyperglycemia (HG) is associated with increased mortality and morbidity in acute ischemic events. Regardless of the tissue or organs involved, the vascular endothelium is a key target of ischemia-reperfusion (I/R) injury severity. Among endothelium-protective strategies, exercise has been widely described as useful. However, whether this strategy is able to impact the deleterious effect of HG on endothelial function during I/R has never been challenged. For this, 48 male Wistar rats were randomized into 4 groups: sedentary (Sed) or exercised (Ex, 45 min/day, 5 days/week for 5 weeks) rats, treated (hyperglycemic, HG) or not (normoglycemic, NG) with streptozotocin (40 mg/kg, 48 h before procedure). Vascular I/R (120/15 min) was performed by clamping the femoral artery. Arterial and downstream muscular perfusions were assessed using laser speckle contrast imaging. Vascular endothelial function was assessed in vivo 15 min after reperfusion. HG was responsible for impairment of reperfusion blood flow as well as endothelial function. Interestingly exercise was able to prevent those impairments in the HG group. In agreement with the previous results, HG increased reactive oxygen species production and decreased nitric oxide bioavailability whereas exercise training normalized these parameters. It, therefore, appears that exercise may be an effective prevention strategy against the exacerbation of vascular and muscular damage by hyperglycemia during I/R.