Peak oxygen uptake after cardiac rehabilitation: a randomized controlled trial of a 12-month maintenance program versus usual care

Rates of compliance and adherence to high-intensity interval training: a systematic review and Meta-analyses

BACKGROUND

To determine rates of compliance (i.e., supervised intervention attendance) and adherence (i.e., unsupervised physical activity completion) to high-intensity interval training (HIIT) among insufficiently active adults and adults with a medical condition, and determine whether compliance and adherence rates were different between HIIT and moderate-intensity continuous training (MICT).

METHODS

Articles on adults in a HIIT intervention and who were either insufficiently active or had a medical condition were included. MEDLINE, EMBASE, PsychINFO, SPORTDiscus, CINAHL, and Web of Science were searched. Article screening and data extraction were completed by two independent reviewers. Risk of bias was assessed using RoB 2.0 or ROBINS-I. Meta-analyses were conducted to discern differences in compliance and adherence between HIIT vs. MICT. Sensitivity analyses, publication bias, sub-group analyses, and quality appraisal were conducted for each meta-analysis.

RESULTS

One hundred eighty-eight unique studies were included (n = 8928 participants). Compliance to HIIT interventions averaged 89.4% (SD:11.8%), while adherence to HIIT averaged 63% (SD: 21.1%). Compliance and adherence to MICT averaged 92.5% (SD:10.6%) and 68.2% (SD:16.2%), respectively. Based on 65 studies included in the meta-analysis, compliance rates were not different between supervised HIIT and MICT interventions [Hedge's g = 0.015 (95%CI: - 0.088-0.118), p = .78]. Results were robust and low risk of publication bias was detected. No differences were detected based on sub-group analyses comparing medical conditions or risk of bias of studies. Quality of the evidence was rated as moderate over concerns in the directness of the evidence. Based on 10 studies, adherence rates were not different between unsupervised HIIT and MICT interventions [Hedge's g = - 0.313 (95%CI: - 0.681-0.056), p = .096]. Sub-group analysis points to differences in adherence rates dependent on the method of outcome measurement. Adherence results should be interpreted with caution due to very low quality of evidence.

CONCLUSIONS

Compliance to HIIT and MICT was high among insufficiently active adults and adults with a medical condition. Adherence to HIIT and MICT was relatively moderate, although there was high heterogeneity and very low quality of evidence. Further research should take into consideration exercise protocols employed, methods of outcome measurement, and measurement timepoints.

REGISTRATION

This review was registered in the PROSPERO database and given the identifier CRD42019103313.

Addition of high-intensity interval training to a moderate intensity continuous training cardiovascular rehabilitation program after ischemic cerebrovascular disease: A randomized controlled trial

Introduction

Moderate intensity continuous training (MICT) is usually recommended for stroke or transient ischemic attack (TIA) patients. High intensity interval training (HIIT) has emerged as a potentially effective method for increasing cardiorespiratory fitness (CRF) among clinical populations. Its effectiveness remains to be demonstrated after stroke. A combined program of HIIT and MICT was designed to create a realistic exercise program implemented for a clinical setting to help patients become more active.

Purpose

This study aimed to compare the effects of a 6-month exercise program with either MICT only or a combination of HIIT and MICT and a control group in terms of CRF, cardiovascular risk factors, functionality, cognitive function (Montreal Cognitive Assessment) and depression markers (Hospital Anxiety and Depression Scale).

Methods

This randomized controlled trial started with 52 participants (33 men and 19 women, mean age: 69.2 ± 10.7) divided into three groups: HIIT + MICT combined, MICT, and control. Both exercise groups consisted of 4 weekly sessions including supervised and at-home exercise. Outcomes were assessed at T0 (baseline measure), T6 (end of exercise protocols), and T12 (follow-up), 40 participants having completed the 12-month follow-up.

Results

At T6, both HIIT+MICT and MICT programs provided a similar increase of CRF (3 ml·min-1·kg-1) from baseline (p < 0.01), while the control group showed a global slight decrease. Despite some decrease of CRF at T12 compared to T6, improvement persisted 6 months post-intervention (HIIT + MICT: p < 0.01 and MICT: p < 0.05). The control group decreased compared with baseline (p < 0.05). The two exercise programs induced a comparable increase in self-reported physical activity and a decrease in anxiety and depression markers. Participants in HIIT + MICT and MICT programs declared a good degree of acceptability assessed by the Acceptability and Preferences Questionnaire.

Conclusion

A 6-month HIIT + MICT combined program and a standard MICT program induced similar improvements in CRF, self-reported physical activity and anxiety and depression markers among patients with prior ischemic stroke or TIA compared with a control group. These effects appear to persist over time. Addition of HIIT was safe and considered acceptable by participants. Our results do not support any superiority of the combination HIIT + MICT nor disadvantage vs. MICT in this population.

Extraordinary claims in the literature on high-intensity interval training (HIIT): IV. Is HIIT associated with higher long-term exercise adherence?

Nonadherence to and dropout from regular exercise and physical activity are important reasons why the field of exercise science has yet to fulfill its promise of improving public health on a global scale. Researchers have claimed that High-Intensity Interval Training (HIIT) is a feasible and sustainable exercise modality that may result in higher long-term adherence than moderate-intensity continuous exercise. If true, this would be a breakthrough discovery that could unlock the potential of exercise as a health-promoting intervention. We performed a systematic search of the literature and identified eight trials comparing HIIT to moderate-intensity continuous exercise, all of which involved follow-up periods of at least 12 months (i.e., SWIFT, Small Steps for Big Changes, SAINTEX-CAD, SMARTEX-HF, Generation 100, FITR, OptimEx-Clin, HITTS). Findings from these trials demonstrate that, while unsupervised, individuals initially assigned to HIIT tend to exercise at lower-than-prescribed intensities and HIIT groups demonstrate no advantage in long-term adherence.

Exercise-based cardiac rehabilitation for coronary heart disease

BACKGROUND

Coronary heart disease (CHD) is the most common cause of death globally. However, with falling CHD mortality rates, an increasing number of people living with CHD may need support to manage their symptoms and prognosis. Exercise-based cardiac rehabilitation (CR) aims to improve the health and outcomes of people with CHD. This is an update of a Cochrane Review previously published in 2016.

OBJECTIVES

To assess the clinical effectiveness and cost-effectiveness of exercise-based CR (exercise training alone or in combination with psychosocial or educational interventions) compared with 'no exercise' control, on mortality, morbidity and health-related quality of life (HRQoL) in people with CHD.

SEARCH METHODS

We updated searches from the previous Cochrane Review, by searching CENTRAL, MEDLINE, Embase, and two other databases in September 2020. We also searched two clinical trials registers in June 2021.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of exercise-based interventions with at least six months' follow-up, compared with 'no exercise' control. The study population comprised adult men and women who have had a myocardial infarction (MI), coronary artery bypass graft (CABG) or percutaneous coronary intervention (PCI), or have angina pectoris, or coronary artery disease.

DATA COLLECTION AND ANALYSIS

We screened all identified references, extracted data and assessed risk of bias according to Cochrane methods. We stratified meta-analysis by duration of follow-up: short-term (6 to 12 months); medium-term (> 12 to 36 months); and long-term ( > 3 years), and used meta-regression to explore potential treatment effect modifiers. We used GRADE for primary outcomes at 6 to 12 months (the most common follow-up time point).  MAIN RESULTS: This review included 85 trials which randomised 23,430 people with CHD. This latest update identified 22 new trials (7795 participants). The population included predominantly post-MI and post-revascularisation patients, with a mean age ranging from 47 to 77 years. In the last decade, the median percentage of women with CHD has increased from 11% to 17%, but females still account for a similarly small percentage of participants recruited overall ( < 15%). Twenty-one of the included trials were performed in low- and middle-income countries (LMICs). Overall trial reporting was poor, although there was evidence of an improvement in quality over the last decade. The median longest follow-up time was 12 months (range 6 months to 19 years). At short-term follow-up (6 to 12 months), exercise-based CR likely results in a slight reduction in all-cause mortality (risk ratio (RR) 0.87, 95% confidence interval (CI) 0.73 to 1.04; 25 trials; moderate certainty evidence), a large reduction in MI (RR 0.72, 95% CI 0.55 to 0.93; 22 trials; number needed to treat for an additional beneficial outcome (NNTB) 75, 95% CI 47 to 298; high certainty evidence), and a large reduction in all-cause hospitalisation (RR 0.58, 95% CI 0.43 to 0.77; 14 trials;  NNTB 12, 95% CI 9 to 21; moderate certainty evidence). Exercise-based CR likely results in little to no difference in risk of cardiovascular mortality (RR 0.88, 95% CI 0.68 to 1.14; 15 trials; moderate certainty evidence), CABG (RR 0.99, 95% CI 0.78 to 1.27; 20 trials; high certainty evidence), and PCI (RR 0.86, 95% CI 0.63 to 1.19; 13 trials; moderate certainty evidence) up to 12 months' follow-up. We are uncertain about the effects of exercise-based CR on cardiovascular hospitalisation, with a wide confidence interval including considerable benefit as well as harm (RR 0.80, 95% CI 0.41 to 1.59; low certainty evidence). There was evidence of substantial heterogeneity across trials for cardiovascular hospitalisations (I2 = 53%), and of small study bias for all-cause hospitalisation, but not for all other outcomes. At medium-term follow-up, although there may be little to no difference in all-cause mortality (RR 0.90, 95% CI 0.80 to 1.02; 15 trials), MI (RR 1.07, 95% CI 0.91 to 1.27; 12 trials), PCI (RR 0.96, 95% CI 0.69 to 1.35; 6 trials), CABG (RR 0.97, 95% CI 0.77 to 1.23; 9 trials), and all-cause hospitalisation (RR 0.92, 95% CI 0.82 to 1.03; 9 trials), a large reduction in cardiovascular mortality was found (RR 0.77, 95% CI 0.63 to 0.93; 5 trials). Evidence is uncertain for difference in risk of cardiovascular hospitalisation (RR 0.92, 95% CI 0.76 to 1.12; 3 trials). At long-term follow-up, although there may be little to no difference in all-cause mortality (RR 0.91, 95% CI 0.75 to 1.10), exercise-based CR may result in a large reduction in cardiovascular mortality (RR 0.58, 95% CI 0.43 to 0.78; 8 trials) and MI (RR 0.67, 95% CI 0.50 to 0.90; 10 trials). Evidence is uncertain for CABG (RR 0.66, 95% CI 0.34 to 1.27; 4 trials), and PCI (RR 0.76, 95% CI 0.48 to 1.20; 3 trials). Meta-regression showed benefits in outcomes were independent of CHD case mix, type of CR, exercise dose, follow-up length, publication year, CR setting, study location, sample size or risk of bias. There was evidence that exercise-based CR may slightly increase HRQoL across several subscales (SF-36 mental component, physical functioning, physical performance, general health, vitality, social functioning and mental health scores) up to 12 months' follow-up; however, these may not be clinically important differences. The eight trial-based economic evaluation studies showed exercise-based CR to be a potentially cost-effective use of resources in terms of gain in quality-adjusted life years (QALYs).

AUTHORS' CONCLUSIONS

This updated Cochrane Review supports the conclusions of the previous version, that exercise-based CR provides important benefits to people with CHD, including reduced risk of MI, a likely small reduction in all-cause mortality, and a large reduction in all-cause hospitalisation, along with associated healthcare costs, and improved HRQoL up to 12 months' follow-up. Over longer-term follow-up, benefits may include reductions in cardiovascular mortality and MI. In the last decade, trials were more likely to include females, and be undertaken in LMICs, increasing the generalisability of findings. Well-designed, adequately-reported RCTs of CR in people with CHD more representative of usual clinical practice are still needed. Trials should explicitly report clinical outcomes, including mortality and hospital admissions, and include validated HRQoL outcome measures, especially over longer-term follow-up, and assess costs and cost-effectiveness.

Systematic Review of Interventions Designed to Maintain or Increase Physical Activity Post-Cardiac Rehabilitation Phase II

Background:

Cardiovascular disease (CVD) continues to be the No. 1 cause of death in the United States and globally, and individuals with a history of a cardiac event are at increased risk for a repeat event. Physical inactivity creates health problems for individuals with chronic heart disease. Evidence shows that physical activity (PA), as a central component of cardiac rehabilitation phase II (CRII), decreases hospital readmission and mortality. Yet, individual adherence to PA tends to decline several months following CRII completion.

Objective:

The purpose of this review was to evaluate current literature for interventions designed to assist individuals diagnosed with myocardial infarction (MI), coronary artery bypass graft (CABG), coronary artery disease (CAD), and percutaneous coronary intervention (PCI) to maintain or increase PA post-CRII.

Methods:

A systematic search of 5 electronic databases including hand-searched articles between 2000 and 2019. Key Medical Subject Headings (MeSH) search terms included cardiac rehabilitation, intervention, exercise or PA, outcomes, compliance, adherence, or maintenance. Only interventions implemented following CRII program completion were included for review.

Results:

Based on the inclusion criteria, the search yielded 19 randomized control trials retained for descriptive analysis. Interventions were categorized into 3 domains. The intervention designs varied widely in terms of duration of the intervention and the length of time to outcome measurement. Most interventions were short-term with only 2 studies offering a long-term intervention of greater than 1 year. Interventions using a theoretical approach most often included a cognitive-behavioral model.

Conclusions:

Interventions offered shortly after completion of CRII may help cardiac patients maintain PA and reduce the risk of experiencing additional cardiac events; however, more quality research is needed. Additional research to examine PA maintenance in older adults (70 years and older) would be valuable based on the increase in average lifespan. Studies with larger and more diverse samples, and less variation in methods and outcomes would greatly increase the ability to conduct a high-quality meta-analysis.

The effects of maintenance cardiac rehabilitation: A systematic review and Meta-analysis, with a focus on sex

Phase III/IV cardiac rehabilitation (CR) is recommended to promote maintenance of benefits achieved during Phase II; there has been no meta-analysis to test this to date. This study determined the effects of maintenance CR on any outcome, with consideration of sex. Seven databases were searched from inception-January 2020. Randomized controlled trials on the effects of maintenance CR in cardiovascular disease patients who had graduated from CR were included. Level of evidence was evaluated with GRADEPro. 819 citations were identified, with 10 trials (21 papers) included (5238 participants; 859 [16.4%] female). Maintenance CR resulted in lower low-density lipoprotein (mean difference [MD]=-0.58; 95% confidence interval [CI]=-1.06--0.10, n = 392) and greater quality of life (MD = 0.28, 95% CI = 0.05-0.52, n = 118) when compared to usual care only. Outcomes for women and sex differences were mixed. In conclusion, maintenance programs appear to sustain patient's quality of life, but more focus on women's outcomes is needed.

[Effects of an interdisciplinary program combining aerobic interval training and dynamic strength in acute coronary syndrome]

INTRODUCTION AND OBJECTIVES

Cardiac rehabilitation has the highest level of recognition in medical guideline references, however there are still little-explored training modalities. We study the effects of an interdisciplinary program after acute coronary syndrome (ACS) in phase II secondary prevention.

METHODS

Between January 2008 and December 2018, 439 patients with stable ischemic heart disease and preserved systolic function were included, as maximum 2 month after the ACS. A combined aerobic resistance training program in a variable continuous method and muscle toning with overload and/or ballast was applied, in addition to nutritional counseling and psychological-educational therapy for 12 weeks.

RESULTS

378 patients finished. The functional capacity increases in the incremental stress test (1.76 METS; CI 95%: 1.59-1.96, p < 0.001) and in the six minutes walking test (32.58 m; CI 95%: 29.24-35.92, p < 0.001). Leisure physical activity in IPAQ increased (763.27 min/week; CI 95%: 583.31-943.16, p < 0.001) and the time sitting during the week decreased (-28.85 min/day; CI 95%: -43.94 to -13.77, p < 0.001). Also, eating habits improved in PREDIMED (2.58 units; CI 95%: 1.43-3.73, p < 0.001), decreased body weight (-0.88 kg; CI 95%: -1.26 to -0.49, p < 0.001), the abdominal perimeter (1.57 cm; CI 95%: 2.23-0.90, p < 0.001) and adipose tissue (-0.80%; CI 95%: -1.10 to -0.51, p < 0.001).

CONCLUSIONS

An interdisciplinary program with high intensity variable continuous training combined with dynamic muscle toning increases functional capacity, the level of physical activity, improves body composition and eating habits in ACS patients.

The effects of 12-months supervised periodized training on health-related physical fitness in coronary artery disease: a randomized controlled trial

We compared the impact of a one-year periodized exercise training versus a non-periodized exercise training on health-related physical fitness (HRPF) including body composition, cardiorespiratory and muscular fitness in patients with coronary artery disease (CAD). Fifty CAD patients (60.4 ± 9.9 years) were randomized to either a periodized training group (PG) (n = 25) or a non-periodized training group (NPG) (n = 25). Both consisted of a combined training programme, performed 3 days/week for 12 months. Thirty-six CAD patients (PG: n = 18, NPG: n = 18) successfully completed the exercise regimes. In both groups, a favourable main effect for time was evident for peak VO₂, peak workload, anaerobic threshold and respiratory compensation point workloads and VO₂, whole body skeletal muscle mass and quality index at 12 months.In conclusion, a periodized model is as effective as a non-periodized model in promoting increases in HRPF outcomes following a one-year intervention. These findings indicate that health-professionals can add variation to cardiac rehabilitation workouts without compromising effectiveness.

Adherence to High-Intensity Interval Training in Cardiac Rehabilitation: A REVIEW AND RECOMMENDATIONS

PURPOSE

High-intensity interval training (HIIT) is gaining popularity as a training approach for patients attending cardiac rehabilitation (CR). While the literature has focused on the efficacy of HIIT for improving cardiorespiratory fitness (CRF), particularly when compared with moderate intensity exercise, less emphasis has been placed on adherence to HIIT. The aim of this review was to summarize the current literature regarding adherence to HIIT in CR patients with coronary artery disease.

REVIEW METHODS

A review identified 36 studies investigating HIIT in CR patients with coronary artery disease. Methods and data were extracted for exercise or training adherence (to attendance, intensity, and duration), feasibility of protocols, and CRF. The review summarizes reporting of adherence; adherence to HIIT and comparator/s; the influence of adherence on changes in CRF; and feasibility of HIIT.

SUMMARY

Adherence to the attendance of HIIT sessions was high and comparable with moderate-intensity exercise. However, adherence to the intensity and duration of HIIT was variable and underreported, which has implications for determining the treatment effect of the exercise interventions being compared. Furthermore, additional research is needed to investigate the utility of home-based HIIT and long-term adherence to HIIT following supervised programs. This review provides recommendations for researchers in the measurement and reporting of adherence to HIIT and other exercise interventions to facilitate a sufficient and consistent approach for future studies. This article also highlights strategies for clinicians to improve adherence, feasibility, and enjoyment of HIIT for their patients.

Sex Differences in Cardiometabolic Health Indicators after HIIT in Patients with Coronary Artery Disease

PURPOSE

Cardiorespiratory fitness (CRF) is an independent predictor of mortality, and females typically achieve smaller improvements in CRF than males after exercise-based cardiac rehabilitation. High-intensity interval training (HIIT) has been shown to produce superior improvements in CRF than traditional cardiac rehabilitation, but the sex differences are unknown. The purpose of this systematic review and meta-analysis was to evaluate sex differences for changes in CRF and cardiometabolic health indicators after HIIT in adults with coronary artery disease (CAD).

METHODS AND RESULTS

A systemic search of five electronic databases for studies examining the effect of HIIT on measured CRF and cardiometabolic health indicators in adults with CAD was performed. Data (published and unpublished) from 14 studies were included in the meta-analyses with approximately eightfold greater male than female participation (n = 836 vs n = 103). Males with CAD achieved a near-significant absolute improvement in CRF (mean difference [MD] = 1.07, 95% confidence interval [CI] = -0.08 to 2.23 mL·kg-1⋅min-1, P = 0.07) after HIIT when compared with control; there were insufficient data to conduct such an analysis in females. Significantly smaller improvements in CRF were experienced by females than males (MD = -1.10, 95% CI = -2.08 to -0.12 mL·kg-1⋅min-1, P = 0.03); there was no sex difference for the relative (percentage) change in CRF after HIIT. Females achieved significantly smaller reductions in body mass index (MD = -0.25, 95% CI = -0.03 to -0.47 kg·m-2, P = 0.02) and fasting blood glucose (MD = -0.38, 95% CI = -0.05 to -0.72, P = 0.03); no sex differences were observed for other cardiometabolic health indicators.

CONCLUSION

There are no sex differences for relative improvements in CRF after HIIT; however, females are greatly underrepresented in trials. Future studies should increase female participation and perform sex-based analyses to determine sex-specific outcomes following HIIT.

Long-term follow-up with a smartphone application improves exercise capacity post cardiac rehabilitation: A randomized controlled trial

BACKGROUND

Mobile health interventions, especially smartphone applications (apps), have been proposed as promising interventions for supporting adherence to healthy behaviour in patients post cardiac rehabilitation (CR). The overall aim of the study was to examine the effect of individualized follow-up with an app for one year on peak oxygen uptake (VO2peak) in patients completing CR.

DESIGN

The study was designed as a single-blinded multicentre randomized controlled trial.

METHODS

The intervention group (IG) received individualized follow-up enabled with an app for one year, while the control group (CG) received usual care. The primary outcome was difference in VO2peak. Secondary outcomes included exercise performance (time to exhaustion, peak incline (%) and peak velocity (km/h)), bodyweight, resting blood pressure, lipid profile, triglycerides, exercise habits, health-related quality of life, health status and self-perceived goal achievement.

RESULTS

In total, 113 patients completing CR (73.4% with coronary artery disease, 16.8% after valve surgery and 9.8% with other heart diseases) were randomly allocated to the IG or CG. Intention to treat analyses showed a statistically significant difference in VO2peak between the groups at follow-up of 2.2 ml/kg/min, 95% confidence interval 0.9-3.5 (p < 0.001). Statistically significant differences were also observed in exercise performance, exercise habits and in self-perceived goal achievement.

CONCLUSIONS

Individualized follow-up for one year with an app significantly improved VO2peak, exercise performance and exercise habits, as well as self-perceived goal achievement, compared with a CG in patients post-CR. There were no statistically significant differences between the groups at follow-up in the other outcome measures evaluated.

Effects of Cardiovascular Interval Training in Healthy Elderly Subjects: A Systematic Review

The aim of this review is to demonstrate the effects of cardiovascular interval training (IT) on healthy elderly subjects. We used the recommendations of the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. The following variables were observed: resting heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MBP), heart rate variability (HRV), baroreflex activity (BA), and maximal oxygen uptake (VO_2max). Studies were searched for in the MedLine, PubMed, and Sport Discus databases considering publications between 1990 and 2019. To find the studies, the keywords used were “Interval and Elderly Training” or “Interval Training and Baroreflex Sensing” or “Interval Training and Aging and Pressure Arterial and Blood Pressure Training” or “Interval Training and Variation in Aging and Heart Rate” or “Interval Training and Sensitivity to the Elderly and Baroreflex” or “Interval Training and Variability in the Elderly and Heart Rate.” The systematic search identified 1,140 hits. The analysis of the study was performed through a critical review of the content. One thousand one hundred forty articles were identified. Of these, 1,108 articles were excluded by checking the articles and abstracts. Finally, 32 studies were selected for full reading while 26 studies were eliminated because they did not contain a methodology according to the purpose of this review. Thus, six studies were included for the final analysis. The PEDro score was used for analyzing the study quality and found 4,8 ± 1,3 points (range: 3–6). Positive results were found with the different IT protocols in the observed variables. Results show that IT protocols can be an efficient method for functional improvement of cardiovascular and cardiorespiratory variables in the healthy elderly, especially HR, SBP, DBP, MAP, HRV, BA, and VO_2max. However, this method can be included in the prescription of aerobic training for the elderly to obtain conditional improvements in the cardiovascular system, thus being an important clinical intervention for the public.

The Effectiveness of Interventions to Maintain Exercise and Physical Activity in Post-Cardiac Rehabilitation Populations: A SYSTEMATIC REVIEW AND META-ANALYSIS OF RANDOMIZED CONTROLLED TRIALS

PURPOSE

Cardiac rehabilitation is a medically supervised program addressing health behavior changes and promoting self-management among individuals with heart disease. This includes initiation of regular physical activity. However, long-term physical activity after cardiac rehabilitation among this population remains a challenge.

METHODS

This study was a systematic review and meta-analysis according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Randomized controlled trials were identified by searching multiple databases and were selected if they evaluated an intervention with a physical activity or exercise component among individuals who completed cardiac rehabilitation. A descriptive synthesis was performed for all studies and means and standard deviations were used for meta-analysis when possible. Risk of bias, heterogeneity, and publication bias were assessed.

RESULTS

Twenty-five studies met the inclusion criteria and 19 were included in the meta-analysis. The mean age of participants across studies was 60 yr and 80% were male. Descriptive synthesis of the studies combined with meta-analysis results provided evidence of increased physical activity among intervention groups compared with control groups at follow-up.

CONCLUSION

There is evidence to support the effectiveness of interventions aimed at maintaining physical activity and exercise among adults who have completed cardiac rehabilitation.

High-Intensity Interval Circuit Training Versus Moderate-Intensity Continuous Training on Cardiorespiratory Fitness in Middle-Aged and Older Women: A Randomized Controlled Trial

High-intensity interval training (HIIT) has similar or better effects than moderate-intensity continuous training (MICT) in increasing peak oxygen consumption (VO_2max), however, it has not been studied when HIIT is applied in a circuit (HIICT). The aim of this study was to compare the effects of a HIICT versus MICT on VO_2max estimated (VO_2max-ES), heart rate (HR) and blood pressure (BP) of middle-aged and older women. A quasi-experimental randomized controlled trial was used. Fifty-four women (67.8 ± 6.2 years) were randomized to either HIICT (n = 18), MICT (n = 18) or non-exercise control group (CG; n = 18) for 18 weeks. Participants in HIICT and MICT trained two days/week (one hour/session). Forty-one participants were assessed (HIICT; n = 17, MICT; n = 12, CG; n = 12). Five adverse events were reported. Cardiorespiratory fitness, HR and BP were measured. The tests were performed before and after the exercise intervention programs. VO_2max-ES showed significant training x group interaction, in which HIICT and MICT were statistically superior to CG. Moreover, HIICT and MICT were statistically better than CG in the diastolic blood pressure after exercise (DBP_ex) interaction. For the systolic blood pressure after exercise (SBP_ex), HIICT was statistically better than CG. In conclusion, both HIICT and MICT generated adaptations in VO_2max-ES and DBP_ex. Furthermore, only HIICT generated positive effects on the SBP_ex. Therefore, both training methods can be considered for use in exercise programs involving middle-aged and older women.

Feasibility of a Smartphone-enabled Cardiac Rehabilitation Program in Male Veterans With Previous Clinical Evidence of Coronary Heart Disease

Cardiac rehabilitation (CR) is recommended for patients with coronary heart disease, however, participation among veterans remains poor. Smartphones may facilitate data transfer and communication between patients and providers, among other benefits. We evaluated the feasibility of a smartphone-enabled CR program in a population of veterans. Qualifying veterans were prospectively enrolled in a single-arm, nonrandomized feasibility study of a smartphone-enabled, home-based CR program, featuring an app with daily reminders to exercise, log vitals, and review educational materials. A coach remotely monitored patients through an online dashboard and scheduled telephone visits. Clinical end points were assessed as an exploratory aim. After 21 veterans provided informed consent, 18 were enrolled and successfully completed at least 30days of the program; 13 completed the entire 12-week intervention. Mean (standard deviation) age was 62 (7) years and 96% were male. Program completers logged a mean (standard deviation) of 3.5 (1.4) exercise sessions and 150 (86) exercise minutes per week. The majority (84%) of program completers reported being satisfied overall with the program. Mean functional capacity improved by 1.0 metabolic equivalents (5.3 to 6.3, 95% confidence interval 0.3 to 1.7; p = 0.008) and mean systolic blood pressure at rest improved by 9.6mm Hg (mean difference 9.6, 95% confidence interval -19.0 to -0.7; p = 0.049) among completers. Smartphone-enabled, home-based CR is feasible in veterans with heart disease and is associated with moderate to high levels of engagement and patient satisfaction.

High-intensity Interval Training Dosage for Heart Failure and Coronary Artery Disease Cardiac Rehabilitation. A Systematic Review and Meta-analysis

INTRODUCTION AND OBJECTIVES

High-interval intensity training (HIT) has been suggested to improve peak VO₂ in cardiac rehabilitation programs. However, the optimal HIT protocol is unknown. The objective of this study was to identify the most effective doses of HIT to optimize peak VO₂ in coronary artery disease (CAD) and heart failure (HF) patients.

METHODS

A search was conducted in 6 databases (MEDLINE, Web of Science, LILACS, CINAHL, Academic Search Complete, and SportDiscus). Studies using a HIT protocol in CAD or HF patients and measuring peak VO₂ were included. The PEDro Scale and Cochrane Collaboration tools were used.

RESULTS

Analyses reported significant improvements in peak VO₂ after HIT in both diseases (P = .000001), with a higher increase in HF patients (P = .03). Nevertheless, in HF patients, there were no improvements when the intensity recovery was ≤ 40% of peak VO₂ (P = .19) and the frequency of training was ≤ 2 d/wk (P = .07). There were significant differences regarding duration in CAD patients, with greater improvements in peak VO₂ when the duration was < 12 weeks (P = .05). In HF, programs lasting < 12 weeks did not significantly improve peak VO₂ (P = .1).

CONCLUSIONS

The HIT is an effective method for improving peak VO₂ in HF and CAD, with a significantly greater increase in HF patients. The recovery intervals should be active and be between 40% and 60% of peak VO₂ in HF patients. Training frequency should be ≥ 2 d/wk for CAD patients and ≥ 3 d/wk for HF patients.

Long-Term Results of High-Intensity Exercise-Based Cardiac Rehabilitation in Revascularized Patients for Symptomatic Coronary Artery Disease

Exercise capacity is a strong predictor of survival rate in patients with and without coronary artery disease. Exercise-based cardiac rehabilitation (CR) with improvements in the peak oxygen uptake (VO_2peak) of 3.5 ml/kg/min or more has been shown to be beneficial in earlier observational studies. Long-term results on VO_2peak after CR are rare. The aim of this study was to assess if a 12-week outpatient CR program including high-intensity interval training would preserve or improve VO_2peak 15 months after CR entry. A total of 133 coronary patients attended the CR program (the Norwegian Ullevaal model). At baseline, at the end of the program, and after 15 months, the patients were evaluated with a cardiopulmonary exercise test, body mass index, blood pressure, self-reported exercise habits, and quality of life (the COOP-WONCA questionnaire). Long-term outcomes were available for 86 patients (65 %). The mean age was 57 ± 9 years and 87% were men. VO_2peak improved significantly from baseline (31.9 ± 7.6 ml/kg/min) to program end (35.9 ± 8.6 ml/kg/min) (p <0.001), and further progress was seen at the long-term follow-up (36.8 ± 9.2 ml/kg/min) (p <0.05). COOP-WONCA was significantly enhanced in all domains (p <0.001) with a meaningful clinical improvement in "physical fitness" from baseline to long-term follow-up. In conclusion, at follow-up, the patients still exercised (mean 2.5 ± 1 times per week) and had improved or preserved their VO_2peak and quality of life.

A scoping review of the psychological responses to interval exercise: is interval exercise a viable alternative to traditional exercise?

While considerable evidence suggests that interval exercise confers numerous physiological adaptations linked to improved health, its psychological consequences and behavioural implications are less clear and the subject of intense debate. The purpose of this scoping review was to catalogue studies investigating the psychological responses to interval exercise in order to identify what psychological outcomes have been assessed, the research methods used, and the results. A secondary objective was to identify research issues and gaps. Forty-two published articles met the review inclusion/exclusion criteria. These studies involved 1258 participants drawn from various active/inactive and healthy/unhealthy populations, and 55 interval exercise protocols (69% high-intensity interval training [HIIT], 27% sprint interval training [SIT], and 4% body-weight interval training [BWIT]). Affect and enjoyment were the most frequently studied psychological outcomes. Post-exercise assessments indicate that overall, enjoyment of, and preferences for interval exercise are equal or greater than for continuous exercise, and participants can hold relatively positive social cognitions regarding interval exercise. Although several methodological issues (e.g., inconsistent use of terminology, measures and protocols) and gaps (e.g., data on adherence and real-world protocols) require attention, from a psychological perspective, the emerging data support the viability of interval exercise as an alternative to continuous exercise.

Effects of high-intensity interval training on cardiometabolic health: a systematic review and meta-analysis of intervention studies

The current review clarifies the cardiometabolic health effects of high-intensity interval training (HIIT) in adults. A systematic search (PubMed) examining HIIT and cardiometabolic health markers was completed on 15 October 2015. Sixty-five intervention studies were included for review and the methodological quality of included studies was assessed using the Downs and Black score. Studies were classified by intervention duration and body mass index classification. Outcomes with at least 5 effect sizes were synthesised using a random-effects meta-analysis of the standardised mean difference (SMD) in cardiometabolic health markers (baseline to postintervention) using Review Manager 5.3. Short-term (ST) HIIT (<12 weeks) significantly improved maximal oxygen uptake (VO₂ max; SMD 0.74, 95% CI 0.36 to 1.12; p<0.001), diastolic blood pressure (DBP; SMD -0.52, 95% CI -0.89 to -0.16; p<0.01) and fasting glucose (SMD -0.35, 95% CI -0.62 to -0.09; p<0.01) in overweight/obese populations. Long-term (LT) HIIT (≥12 weeks) significantly improved waist circumference (SMD -0.20, 95% CI -0.38 to -0.01; p<0.05), % body fat (SMD -0.40, 95% CI -0.74 to -0.06; p<0.05), VO₂ max (SMD 1.20, 95% CI 0.57 to 1.83; p<0.001), resting heart rate (SMD -0.33, 95% CI -0.56 to -0.09; p<0.01), systolic blood pressure (SMD -0.35, 95% CI -0.60 to -0.09; p<0.01) and DBP (SMD -0.38, 95% CI -0.65 to -0.10; p<0.01) in overweight/obese populations. HIIT demonstrated no effect on insulin, lipid profile, C reactive protein or interleukin 6 in overweight/obese populations. In normal weight populations, ST-HIIT and LT-HIIT significantly improved VO₂ max, but no other significant effects were observed. Current evidence suggests that ST-HIIT and LT-HIIT can increase VO₂ max and improve some cardiometabolic risk factors in overweight/obese populations.

Long-Term Outcomes of Cardiac Rehabilitation in Diabetic and Non-diabetic Patients With Myocardial Infarction

OBJECTIVE

To investigate the long-term outcomes of cardiac rehabilitation (CR) on exercise capacity in diabetic (DM) and non-diabetic (non-DM) patients with myocardial infarction (MI).

METHODS

Of the MI patients who received hospital-based CR from February 2012 to January 2014, we retrospectively reviewed the medical records of the patients who continued follow-up through the outpatient clinic and community-based self-exercise after CR. A total of 37 patients (12 with DM and 25 without DM) were included in this study. Exercise capacity was measured by symptom-limited exercise tests before and after hospital-based CR and 1 year after the onset of MI.

RESULTS

Before the CR, the DM group had significantly lower exercise capacity in exercise times, peak oxygen consumption (VO2peak), and metabolic equivalent tasks (METs) than did the non-DM group. After the CR, both groups showed significantly improved exercise capacity, but the DM group had significantly lower exercise capacity in exercise times, submaximal rate pressure products (RPPsubmax), VO2peak, and METs. One year after the onset of the MI, the DM group had significantly lower exercise capacity in exercise times, RPPsubmax, and VO2peak than did the non-DM group, and neither group showed a significant difference in exercise capacity between before and after the CR.

CONCLUSION

As a result of continued follow-up through an outpatient clinic and community-based self-exercise after hospital-based CR in patients with MI, the DM group still had lower exercise capacity than did the non-DM group 1 year after the onset of MI, but both groups maintained their improved exercise capacity following hospital-based CR.

The effects of high-intensity interval training on glucose regulation and insulin resistance: a meta-analysis

The aim of this meta-analysis was to quantify the effects of high-intensity interval training (HIIT) on markers of glucose regulation and insulin resistance compared with control conditions (CON) or continuous training (CT). Databases were searched for HIIT interventions based upon the inclusion criteria: training ≥2 weeks, adult participants and outcome measurements that included insulin resistance, fasting glucose, HbA1c or fasting insulin. Dual interventions and participants with type 1 diabetes were excluded. Fifty studies were included. There was a reduction in insulin resistance following HIIT compared with both CON and CT (HIIT vs. CON: standardized mean difference [SMD] = -0.49, confidence intervals [CIs] -0.87 to -0.12, P = 0.009; CT: SMD = -0.35, -0.68 to -0.02, P = 0.036). Compared with CON, HbA1c decreased by 0.19% (-0.36 to -0.03, P = 0.021) and body weight decreased by 1.3 kg (-1.9 to -0.7, P < 0.001). There were no statistically significant differences between groups in other outcomes overall. However, participants at risk of or with type 2 diabetes experienced reductions in fasting glucose (-0.92 mmol L(-1), -1.22 to -0.62, P < 0.001) compared with CON. HIIT appears effective at improving metabolic health, particularly in those at risk of or with type 2 diabetes. Larger randomized controlled trials of longer duration than those included in this meta-analysis are required to confirm these results.