High-intensity interval training versus moderate-intensity continuous training on patient quality of life in cardiovascular disease: a systematic review and meta-analysis

Effects of combined high-intensity interval and moderate-intensity continuous training vs. moderate-intensity continuous training alone in male adolescents: a randomized controlled trial

INTRODUCTION

This study aims to investigate the combining effects of high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) compared to MICT alone on physical fitness, academic performance, and anxiety levels among adolescents in a school setting.

METHODS

Sixty male adolescents were randomly assigned to either an experimental group (HIIT + MICT) or a control group (MICT only) for 12 weeks. Physical fitness was assessed using lung capacity, a 50-meter sprint, a standing long jump, and a 1000-meter run. Anxiety levels were measured using the Zung Self-Rating Anxiety Scale, and cognitive performance through academic evaluations. Statistical analyses included Shapiro-Wilk, Mann-Whitney U, unpaired t-tests, chi-square, and McNemar tests.

RESULTS

After 12 weeks, the experimental group showed a significant increase in lung capacity (10.30 ml/kg) compared to the control group (3.18 ml/kg, P = 0.03). Sprint and run completion times were also significantly faster in the experimental group (P < 0.01 and P = 0.02), with greater improvements in the long jump (P = 0.01). Academic performance and anxiety levels improved significantly in the experimental group (P = 0.02 and P < 0.01), while the control group exhibited no significant changes.

CONCLUSION

This study demonstrated that combining HIIT with MICT results in greater improvements in adolescent cardiorespiratory fitness, anaerobic performance, academic outcomes, and anxiety levels compared to MICT alone. These findings support the incorporation of HIIT alongside traditional MICT in adolescents.

TRIAL REGISTRATION

The study was retrospectively registered in the clinical trials registry on 26/04/2023 (ChiCTR2300070895).

Effects of high-intensity interval training versus moderate-intensity continuous training on cardiorespiratory and exercise capacity in patients with coronary artery disease: A systematic review and meta-analysis

BACKGROUND

With the increasing utilization of cardiac rehabilitation in clinical treatment and prognosis for patients with cardiovascular diseases, exercise training has become a crucial component. High-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) are commonly employed in rehabilitating patients with cardiovascular diseases. However, further investigation is required to determine whether HIIT and MICT can effectively enhance the prognosis of patients with coronary artery disease. Therefore, this study aims to assess the effectiveness of HIIT and MICT interventions, optimal intervention duration for different intensity levels of training, as well as effective training modalities that improve cardiorespiratory function and exercise capacity among patients.

METHODS

We conducted a comprehensive search of the Cochrane Library, PubMed, EMbase, Web of Science, and CINAHL databases for randomized controlled trials (RCTs) pertaining to high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) interventions in patients with coronary artery disease from inception until publication on September 26, 2024. Two independent researchers assessed articles that met the inclusion criteria and analyzed the results using Sata 17.0 software. Forest plots were employed to evaluate the impact of HIIT and MICT on outcome indicators. Sensitivity analysis and funnel plot assessment were performed to examine publication bias. Subgroup analysis was conducted to determine optimal intervention duration and training methods.

RESULTS

A total of 22 studies with 1364 patients were included in the study, including the HIIT group (n = 685) and the MICT group (n = 679). The results showed that compared to MICT, HIIT significantly increased PeakVO2(Peak oxygen uptake)[WMD = 1.42mL /kg/min 95%CI (0.87, 1.98), P = 0.870, I2 = 0%], 6MWT(6-minute walk test)[WMD = 18.60m 95%CI (2.29, 34.92), P = 0.789, I2 = 0%], PHR(Peak heart rate)[WMD = 4.21bpm 95%CI (1.07, 7.36), P = 0.865, I2 = 0%], DBP(diastolic blood pressure)[WMD = 3.43mmHg 95%CI (1.09, 5.76), P = 0.004, I2 = 60.2%]. However, in LVEF(left- ventricular ejection fraction)[WMD = 0.32mL 95%CI (-1.83, 2.46), P = 0.699, I2 = 0%], LVEDV(left ventricular end-diastolic volume)[WMD = 0.91 ml 95%CI (-1.83, 2.46), P = 0.995, I2 = 0%] and SBP(systolic blood pressure)[WMD = 1.85mmHg 95%CI (-0.23, 3.93),P = 0.266, I2 = 18.2%], there was no significant difference between HIIT and MICT.

CONCLUSION

Based on the findings of this systematic review, HIIT demonstrates superior efficacy compared to MICT in enhancing PeakVO2, PHR, 6MWT and DBP. However, no significant differences were observed in LVEF, LVEDV, and SBP. In summary, HIIT exhibits potential for improving cardiopulmonary function and exercise capacity among patients with coronary artery disease.

Exercise type and settings, quality of life, and mental health in coronary artery disease: a network meta-analysis

BACKGROUND AND AIMS

Individuals with coronary artery disease have poorer mental health, health-related quality of life (HR-QoL), and cognition compared with (age-matched) controls. Exercise training may attenuate these effects. The aim is to systematically review and meta-analyse the effects of different exercise types and settings on brain structure/function, cognition, HR-QoL, mental health (e.g. depression, anxiety), and sleep in patients with coronary artery disease.

METHODS

A systematic search was conducted and a network meta-analysis compared (i) exercise types, high-intensity interval training (HIIT), HIIT + resistance (HIIT + R), moderate-intensity training (MIT), MIT + R and stretching-toning-balance training, and (ii) exercise settings, in-person and home-based.

RESULTS

A total of 42 randomized controlled trials with a parallel group design were identified, of which 36 were included in the meta-analysis. Few studies included cognition (n = 2), sleep (n = 2), and none brain structure/function (n = 0). Most studies examined HR-QoL (n = 30), depression (n = 15), and anxiety (n = 9), in which outcomes were meta-analysed. HIIT + R, HIIT, and MIT were associated with improved HR-QoL vs. no exercise (i.e. usual care) [standardized mean difference, SMD: 1.53 (95% confidence interval 0.83; 2.24), 0.44 (0.15; 0.73), and 0.44 (0.20; 0.67), respectively]. In-person exercise was associated with larger and significant improvements [HR-QoL SMD: 0.51 (0.28; 0.74), depressive SMD: -0.55 (-1.03; -0.07), and anxiety symptoms SMD: -1.16 (-2.05; -0.26)] compared with no exercise, whereas home-based programmes were not significantly associated with improvements in these outcomes. Findings were robust in secondary (i.e. intervention duration and volume) and sensitivity analyses excluding high risk of bias studies.

CONCLUSIONS

Exercise training, especially in-person sessions, was associated with improved HR-QoL, depression and anxiety, independently of exercise type. However, this study raises concern about the effectiveness of home-based programmes in improving these outcomes.Study protocol was registered in PROSPERO (ID: CRD42023402569).

The effects of high-intensity interval training and moderate-intensity continuous training on patients underwent Coronary Artery Bypass Graft surgery; a systematic review

OBJECTIVES

To our knowledge, there is no clear consensus on a definitive cardiac rehabilitation method for patients undergoing Coronary Artery Bypass Graft (CABG). We conducted this systematic review to compare and evaluate the effects of two of the most frequent cardiac rehabilitation modalities, high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT), on cardiopulmonary variables.

METHODS

We carried out a systematic search of the databases PubMed, Web of Science, Embase, Scopus, and Google Scholar. Following the removal of duplicate results, the original search yielded 385 citations. We identified four randomized clinical trials after reviewing titles, abstracts, and potential full-text studies. We utilized the Cochrane Risk of Bias Tool (RoB2) to assess the risk of bias.

RESULTS

We included four randomized clinical trials involving 143 people. All trials included individuals who had CABG and completed HIIT or MICT sessions for at least four weeks. The findings indicated that HIIT programs may improve functional capacity, heart rate variability indices, and blood pressure management while lowering brain natriuretic peptide (BNP1-32) and N-terminal pro-b-type natriuretic peptide (NT-proBNP1-76) levels.

CONCLUSION

Given the findings, it appeared that supervised high-intensity exercise regimens could be more useful to patients. Following the surgery, HIIT therapy improves exercise capacity, the autonomic nervous system, volume overload, and blood pressure regulation.

High-Intensity Interval Training vs. Medium-Intensity Continuous Training in Cardiac Rehabilitation Programs: A Narrative Review

Exercise-based cardiac rehabilitation (ExCR) programs are essential for patients diagnosed with cardiac diseases. Studies have shown that they aid in the rehabilitation process and may even facilitate a return to previous cardiorespiratory fitness. Also, patients who enroll and follow such programs have shown a lower rate of complications and mortality in the long run. The results vary depending on the type of program followed and the degree of debilitation the disease has caused. Therefore, in order to obtain optimal results, it is ideal to tailor each ExCR program to the individual profile of each patient. At the moment, the two most studied and employed training types are medium-intensity continuous training (MICT) and high-intensity interval training (HIIT). For most of the time, MICT was the first-choice program for patients with cardiovascular disease. In recent years, however, more and more studies have pointed towards the benefits of HIIT and how it better aids patients in recovering their cardiovascular fitness. Generally, MICT is more suited for patients with a severe degradation in functional capacity and who require a higher degree of safety (e.g., elderly, with a high number of comorbidities). On the other hand, while HIIT is more demanding, it appears to offer better outcomes. Therefore, this review aimed to summarize information from different publications on both types of training regimens in ExCR and assess their utility in current clinical practice.

The Effects of Physical Activity and the Consequences of Physical Inactivity in Adult Patients with Congenital Heart Disease During the COVID-19 Pandemic

BACKGROUND

The ongoing COVID-19 pandemic has infected more than 500 million people worldwide. Several measures have been taken to reduce the spread of the virus and the saturation of intensive care units: among them, a lockdown (LD) was declared in Italy on 9 March 2020. As a result, gyms, public parks, sports fields, outdoor play areas, schools, and multiple commercial activities have been closed. The consequences of physical inactivity can be dramatic in adult patients with congenital heart disease (ACHD), in which the benefit of regular exercise is well known. In this study, we investigated the effects of reduced physical activity during the COVID-19 pandemic on ACHD's exercise capacity.

MATERIALS AND METHODS

Patients who performed exercise or cardiopulmonary exercise tests from October 2019 to February 2020 and one year after lockdown with the same protocol were retrospectively enrolled in our database.

INCLUSION CRITERIA

ACHD patients aged ≥ 18 years old under regular follow-up.

EXCLUSION CRITERIA

significant clinical and/or therapeutic changes between the two tests; significant illness occurred between the two tests, including COVID-19 infection; interruption of one of the tests for reasons other than muscle exhaustion.

RESULTS

Thirty-eight patients (55.6% males) met the inclusion criteria. Before the lockdown, 17 patients (group A) were engaged in regular physical activity (RPA), and 20 patients (group B) had a sedentary lifestyle. After LD, in group A, (a) the weekly amount of physical activity reduced with statistical significance from 115 ± 46 min/week to 91 ± 64 min/week (-21%, p = 0.03); (b) the BMI did not change; (c) the duration of exercise test and VO2 max at cardiopulmonary exercise test showed a significant reduction after the LD. In group B, BMI and exercise parameters did not show any difference.

CONCLUSIONS

The COVID-19 pandemic dramatically changed the habits of ACHD patients, significantly reducing their possibility to exercise. Our data analyzed in this extraordinary situation again demonstrated that physical inactivity in ACHD worsens functional capacity, as highlighted by VO2 max. Regular exercise should be encouraged in ACHD patients to preserve functional capacity.

From the armchair to contemporary cardiac rehabilitation: the remarkable ongoing journey of exercise training in ischemic heart disease

Exercise is an important physiological activity with several health benefits. In the setting of ischemic heart disease (IHD), the view toward exercise has greatly evolved throughout the years, concurrently to several major advances in the management of this complex entity. Currently, exercise training has broad applications across the IHD continuum as a powerful tool in its overall management, being a core component of comprehensive cardiac rehabilitation programs. Beyond this, exercise has also been incorporated as an integral part of contemporary methodologies aiming to provide diagnostic and prognostic data, such as cardiopulmonary exercise stress testing or stress echocardiography. In this article, we provide a pragmatic overview concerning the role of exercise in IHD, with a focus on its incorporation in cardiac rehabilitation frameworks, while also discussing some of the challenges and unmet needs concerning these interventions.

High-intensity interval training improves cardiomyocyte contractile function and myofilament sensitivity to intracellular Ca2+ in obese rats

High-intensity interval training (HIIT) has shown significant results in addressing adiposity and risk factors associated with obesity. However, there are no studies that investigate the effects of HIIT on contractility and intracellular Ca2+ handling. The purpose of this study was to explore the impact of HIIT on cardiomyocyte contractile function and intracellular Ca2+ handling in rats in which obesity was induced by a saturated high-fat diet (HFD). Male Wistar rats were initially randomized into a standard diet and a HFD group. The experimental protocol spanned 23 weeks, comprising the induction and maintenance of obesity (15 weeks) followed by HIIT treatment (8 weeks). Performance was assessed using the maximum oxygen consumption test (V ̇ O 2 max ${{\dot{V}}_{{{{\mathrm{O}}}_{\mathrm{2}}}{\mathrm{max}}}}$ ). Evaluation encompassed cardiac, adipose and skeletal muscle histology, as well as contractility and intracellular Ca2+ handling. HIIT resulted in a reduction in visceral area, an increase inV ̇ O 2 max ${{\dot{V}}_{{{{\mathrm{O}}}_{\mathrm{2}}}{\mathrm{max}}}}$ , and an augmentation of gastrocnemius fibre diameter in obese subjects. Additionally, HIIT led to a decrease in collagen fraction, an increase in percentage shortening, and a reduction in systolic Ca2+/percentage shortening and systolic Ca2+/maximum shortening rates. HIIT induces physiological cardiac remodelling, enhancing the contractile function of cardiomyocytes and improving myofilament sensitivity to Ca2+ in the context of obesity. This approach not only enhances cardiorespiratory and physical performance but also reduces visceral area and prevents interstitial fibrosis.

The impact of high intensity training and sports on recipients of solid organ transplants: a narrative review

Objectives

High intensity exercise in individuals post solid organ transplant (SOT) remains a largely understudied phenomenon, with potential risks and benefits. Additionally, the optimal training protocols are still unclear. This narrative review aimed to explore the impact of high-intensity exercise training and strenuous sports on solid organ transplant recipients (SOTRs).

Methods

We conducted a narrative review of intervention studies of any design that included high-intensity exercise training and cross-sectional studies of strenuous sports and activities. Additionally, we reviewed individual reports documenting post-SOT performance at highly competitive or physiological levels. We used MEDLINE to search for relevant articles followed by a manual search for additional articles. Data were extracted and results were summarized.

Results

High-intensity and strenuous exercise appears to be safe among stable SOTRs. High-intensity protocols consistently demonstrated improvements in VO2peak and a reduction in coronary artery disease prevalence, though findings related to body composition, health-related quality of life outcomes, and cardiovascular exercise variables were inconsistent. Pre-transplant athletes showcase notable achievements and physiological adaptations post-transplantation, highlighting the capacity for athletic performance among this population. However, caution is warranted in interpreting the findings from these studies due to limitations in generalizability and other methodological limitations.

Conclusion

As evidenced by current literature, high intensity exercise emerges as a promising exercise method for safely improving various physiological parameters, and reducing the prevalence of coronary heart disease in SOTRs. It can induce similar or greater effects to moderate intensity exercise, however follow-up studies indicate low retention. Further research of higher methodological rigor is warranted in this field to advance understanding, and to guide evidence-based practice.

Exercise intensity prescription in cardiovascular rehabilitation: bridging the gap between best evidence and clinical practice

Optimizing endurance exercise intensity prescription is crucial to maximize the clinical benefits and minimize complications for individuals at risk for or with cardiovascular disease (CVD). However, standardization remains incomplete due to variations in clinical guidelines. This review provides a practical and updated guide for health professionals on how to prescribe endurance exercise intensity for cardiovascular rehabilitation (CR) populations, addressing international guidelines, practical applicability across diverse clinical settings and resource availabilities. In the context of CR, cardiopulmonary exercise test (CPET) is considered the gold standard assessment, and prescription based on ventilatory thresholds (VTs) is the preferable methodology. In settings where this approach isn't accessible, which is frequently the case in low-resource environments, approximating VTs involves combining objective assessments-ideally, exercise tests without gas exchange analyses, but at least alternative functional tests like the 6-minute walk test-with subjective methods for adjusting prescriptions, such as Borg's ratings of perceived exertion and the Talk Test. Therefore, enhancing exercise intensity prescription and offering personalized physical activity guidance to patients at risk for or with CVD rely on aligning workouts with individual physiological changes. A tailored prescription promotes a consistent and impactful exercise routine for enhancing health outcomes, considering patient preferences and motivations. Consequently, the selection and implementation of the best possible approach should consider available resources, with an ongoing emphasis on strategies to improve the delivery quality of exercise training in the context of FITT-VP prescription model (frequency, intensity, time, type, volume, and progression).

Exercise and brain health in patients with coronary artery disease: study protocol for the HEART-BRAIN randomized controlled trial

Introduction

Patients with coronary artery disease (CAD) have a higher risk of developing cognitive impairment and mental health disorders compared to the general population. Physical exercise might improve their brain health. The overall goal of the HEART-BRAIN randomized controlled trial (RCT) is to investigate the effects of different types of exercise on brain health outcomes in patients with CAD, and the underlying mechanisms.

Methods

This three-arm, single-blinded RCT will include 90 patients with CAD (50-75 years). Participants will be randomized into: (1) control group-usual care (n = 30), (2) aerobic high-intensity interval training (HIIT) (n = 30), or (3) HIIT combined with resistance exercise training (n = 30). The 12-week intervention includes 3 supervised sessions (45-min each) per week for the exercise groups. Outcomes will be assessed at baseline and post-intervention. The primary outcome is to determine changes in cerebral blood flow assessed by magnetic resonance imaging. Secondary outcomes include changes in brain vascularization, cognitive measures (i.e., general cognition, executive function and episodic memory), and cardiorespiratory fitness. Additional health-related outcomes, and several potential mediators and moderators will be investigated (i.e., brain structure and function, cardiovascular and brain-based biomarkers, hemodynamics, physical function, body composition, mental health, and lifestyle behavior).

Conclusion

The HEART-BRAIN RCT will provide novel insights on how exercise can impact brain health in patients with CAD and the potential mechanisms explaining the heart-brain connection, such as changes in cerebral blood flow. The results may have important clinical implications by increasing the evidence on the effectiveness of exercise-based strategies to delay cognitive decline in this high-risk population.

Clinical trial registration

ClinicalTrials.gov, identifier [NCT06214624].

From Sprint to Recovery: LSTM-Powered Heart Rate Recovery Forecasting in HIIT Sessions

In recent years, the growing interest in applying artificial intelligence to the healthcare domain, especially in the monitoring and control of health status during fitness activities, has opened new opportunities in understanding and enhancing human performance and health. This interdisciplinary approach, merging cutting-edge AI with exercise physiology, offers promising avenues for personalized healthcare, optimized athletic training, and advanced health monitoring techniques. Current study addressing a critical aspect of exercise physiology: the forecasting of heart rate (HR) recovery patterns following high-intensity intervals. In pursuit of this objective, a comprehensive deep learning framework is developed, designed to forecast HR recovery patterns. This system integrates signal processing techniques combined with advanced deep learning architectures to facilitate real-time HR measurements and predict future HR dynamics during high-intensity interval training. Central to the proposed approach is a long short-term memory (LSTM) based encoder-decoder architecture. To enhance the model's accuracy and robustness, a task-specific loss function is employed. This function not only calculates standard HR errors but also incorporates HR pattern slopes and angles. This approach has achieved promising results, with the model demonstrating strong performance. The mean absolute error in HR forecasting is 3.5 bpm for the encoder and 3.8 bpm for the decoder parts.

Exercise Effects on Health-Related Quality of Life (HRQOL), Muscular Function, Cardiorespiratory Function, and Body Composition in Smokers: A Narrative Review

Smoking is amongst the leading global threats with high incidences of preventable premature mortality, morbidity, and various chronic diseases. The World Health Organization (WHO) proclaims a decrease in the prevalence of daily smoking in both males and females from 1980 to 2012, however, the number of regular smokers since then has exponentially increased. The low socio-income status individuals contribute greatly towards tobacco-attributable diseases due to limited access to healthcare systems, mostly in developing countries as compared to developed countries. Smoking affects the optimal functioning of the human body, which results in altered body system processes. Although a high intake of nicotine can lead to prolonged adherence and dependence on smoking, other factors, such as an individual's level of health-related quality of life (HRQOL), stress, depression, and anxiety, can produce similar effects. Smoking has a wide impact on lifestyle factors, which explains the increase in the number of sedentary smokers with decreased health fitness levels and poor lifestyle conditions. Therefore, this study seeks to investigate the exercise effects on health-related quality of life (HRQOL), muscular function, cardiorespiratory function, and body composition in smokers. Concurrently, exercise as an intervention has been sourced as a rehabilitation strategy during smoking cessation programmes to restore the diminishing health components, however, a high rate of relapse occurs due to intolerable withdrawal symptoms.