Effects of interval cycle training with or without strength training on vascular reactivity in heart failure patients

Clinimetric Properties of the Steep Ramp Test to Assess Cardiorespiratory Fitness, Its Underlying Physiological Responses, and Its Current Applications: A Scoping Review

OBJECTIVE

Providing an overview of the clinimetric properties of the steep ramp test (SRT)-a short-term maximal exercise test-to assess cardiorespiratory fitness (CRF), describing its underlying physiological responses, and summarizing its applications in current clinical and research practice.

DATA SOURCES

MEDLINE (through PubMed), CINAHL Complete, Cochrane Library, EMBASE, and PsycINFO were searched for studies published up to July 2023, using keywords for SRT and CRF.

STUDY SELECTION

Eligible studies involved the SRT as research subject or measurement instrument and were available as full text articles in English or Dutch.

DATA EXTRACTION

Two independent assessors performed data extraction. Data addressing clinimetric properties, physiological responses, and applications of the SRT were tabulated.

DATA SYNTHESIS

In total, 370 studies were found, of which 39 were included in this study. In several healthy and patient populations, correlation coefficients between the work rate at peak exercise (WRpeak) attained at the SRT and oxygen uptake at peak exercise during cardiopulmonary exercise testing (CPET) ranged from .771-.958 (criterion validity). Repeated measurements showed intraclass correlation coefficients ranging from .908-.996 for WRpeak attained with the first and second SRT (test-retest reliability). Physiological parameters, like heart rate and minute ventilation at peak exercise, indicated that the SRT puts a lower burden on the cardiopulmonary system compared to CPET. The SRT is mostly used to assess CRF, among others as part of preoperative risk assessment, and to personalize interval training intensity.

CONCLUSIONS

The SRT is a practical short-term maximal exercise test that is valid for CRF assessment and to monitor changes in CRF over time in various healthy and patient populations. Its clinimetric properties and potential applications make the SRT of interest for a widespread implementation of CRF assessment in clinical and research practice and for personalizing training intensity and monitoring longitudinal changes in CRF.

Effects of high-intensity interval training on vascular function in patients with cardiovascular disease: a systematic review and meta-analysis

Background: Exercise training improves endothelial function in patients with cardiovascular disease (CVD). However, the influence of training variables remains unclear. The aim of this study was to evaluate the effect of high-intensity interval training (HIIT), compared to moderate intensity training (MIT) and other exercise modalities (i.e., resistance and combined exercise), on endothelial function, assessed by arterial flow-mediated dilation (FMD) or endothelial progenitor cells (EPCs), in patients with CVD. Secondly, we investigated the influence of other training variables (i.e., HIIT protocol). Methods: The PICOS strategy was used to identify randomised and non-randomised studies comparing the effect of HIIT and other exercise modalities (e.g., MIT) on endothelial function in patients with CVD. Electronic searches were carried out in Pubmed, Embase, and Web of Science up to November 2022. The TESTEX scale was used to evaluate the methodological quality of the included studies. Random-effects models of between-group mean difference (MD) were estimated. A positive MD indicated an effect in favour of HIIT. Heterogeneity analyses were performed by the chi-square test and I 2 index. Subgroup analyses evaluated the influence of potential moderator variables. Results: Fourteen studies (13; 92.9% randomised) were included. Most of the studies trained 3 days a week for 12 weeks and performed long HIIT. No statistically significant differences were found between HIIT and MIT for improving brachial FMD in patients with coronary artery disease (CAD) and heart failure with reduced ejection fraction (HFrEF) (8 studies; MD+ = 0.91% [95% confidence interval (CI) = -0.06, 1.88]). However, subgroup analyses showed that long HIIT (i.e., > 1 min) is better than MIT for enhancing FMD (5 studies; MD+ = 1.46% [95% CI = 0.35, 2.57]), while no differences were found between short HIIT (i.e., ≤ 1 min) and MIT (3 studies; MD+ = -0.41% [95% CI = -1.64, 0.82]). Insufficient data prevented pooled analysis for EPCs, and individual studies failed to find statistically significant differences (p > .050) between HIIT and other exercise modalities in increasing EPCs. Discussion: Poor methodological quality could limit the precision of the current results and increase the inconsistency. Long HIIT is superior to MIT for improving FMD in patients with CAD or HFrEF. Future studies comparing HIIT to other exercise modalities, as well as the effect on EPCs and in HF with preserved ejection fraction are required. Systematic Review Registration: https://www.crd.york.ac.uk/PROSPERO/#myprospero, identifier CRD42022358156.

Effects and Optimal Dose of Exercise on Endothelial Function in Patients with Heart Failure: A Systematic Review and Meta-Analysis

BACKGROUND

Exercise-based cardiac rehabilitation (CR) is considered an effective treatment for enhancing endothelial function in patients with heart failure (HF). However, recent studies have been published and the optimal "dose" of exercise required to increase the benefits of exercise-based CR programmes on endothelial function is still unknown.

OBJECTIVES

(a) To estimate the effect of exercise-based CR on endothelial function, assessed by flow-mediated dilation (FMD), in patients with HF; (b) to determine whether high-intensity interval training (HIIT) is better than moderate-intensity training (MIT) for improving FMD; and (c) to investigate the influence of exercise modality (i.e. resistance exercise vs. aerobic exercise and combined exercise vs. aerobic exercise) on the improvement of endothelial function.

METHODS

Electronic searches were carried out in PubMed, Embase, and Scopus up to February 2022. Random-effects models of between-group mean differences were estimated. Heterogeneity analyses were performed by means of the chi-square test and I² index. Subgroup analyses and meta-regressions were used to test the influence of potential moderator variables on the effect of exercise.

RESULTS

We found a FMD increase of 3.09% (95% confidence interval [CI] = 2.01, 4.17) in favour of aerobic-based CR programmes compared with control groups in patients with HF and reduced ejection fraction (HFrEF). However, the results of included studies were inconsistent (p < .001; I² = 95.2%). Higher FMD improvement was found in studies which were randomised, reported radial FMD, or performed higher number of training sessions a week. Moreover, HIIT enhanced FMD to a greater extent than MIT (2.35% [95% CI = 0.49, 4.22]) in patients with HFrEF. Insufficient data prevented pooled analyses for the effect of exercise in patients with HF and preserved ejection fraction and the influence of exercise modality on the improvement of endothelial function.

CONCLUSION

Aerobic-based CR is a non-pharmacological treatment for enhancing endothelial function in patients with HFrEF. However, higher training frequency and HIIT induce greater adaptation of endothelial function in these patients, which should betaken into consideration when designing exercise-based CR programmes. Trial registration The protocol was prospectively registered on the PROSPERO database (CRD42022304687).

Relationship of arterial tonometry and exercise in patients with chronic heart failure: a systematic review with meta-analysis and trial sequential analysis

BACKGROUND

Arterial stiffness is a common characteristic in patients with chronic heart failure (CHF), and arterial tonometric technologies related to arterial stiffness are novel and effective methods and have an important value in the diagnosis and prognosis of CHF. In terms of ameliorating arterial stiffness in patients with CHF, exercise training is considered an adjuvant treatment and also an effective means in the diagnosis and judgment of prognosis. However, there are huge controversies and inconsistencies in these aspects. The objective of this meta-analysis was to systematically test the connection of arterial tonometry and exercise in patients with CHF.

METHODS

Databases, including MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, were accessed from inception to 7 March 2022. The meta-analysis was then conducted, and trial sequential analysis (TSA) was performed jointly to further verify our tests and reach more convincing conclusions by using RevMan version 5.4 software, STATA version 16.0 software, and TSA version 0.9.5.10 Beta software.

RESULTS

Eighteen articles were included, with a total of 876 participants satisfying the inclusion criteria. The pooling revealed that flow-mediated dilation (FMD) was lower in basal condition [standardized mean difference (SMD): - 2.28%, 95% confidence interval (CI) - 3.47 to - 1.08, P < 0.001] and improved significantly after exercise (SMD: 5.96%, 95% CI 2.81 to 9.05, P < 0.001) in patients with heart failure with reduced ejection fraction (HFrEF) compared with healthy participants. The high-intensity training exercise was more beneficial (SMD: 2.88%, 95% CI 1.78 to 3.97, P < 0.001) than the moderate-intensity training exercise to improve FMD in patients with CHF. For augmentation index (AIx), our study indicated no significant differences (SMD: 0.50%, 95% CI - 0.05 to 1.05, P = 0.074) in patients with heart failure with preserved ejection fraction (HFpEF) compared with healthy participants. However, other outcomes of our study were not identified after further verification using TSA, and more high-quality studies are needed to reach definitive conclusions in the future.

CONCLUSIONS

This review shows that FMD is lower in basal condition and improves significantly after exercise in patients with HFrEF compared with healthy population; high-intensity training exercise is more beneficial than moderate-intensity training exercise to improve FMD in patients with CHF; besides, there are no significant differences in AIx in patients with HFpEF compared with the healthy population. More high-quality studies on this topic are warranted.

Exercise Training Enhances Angiogenesis-Related Gene Responses in Skeletal Muscle of Patients with Chronic Heart Failure

Peripheral myopathy consists of a hallmark of heart failure (HF). Exercise enhanced skeletal muscle angiogenesis, and thus, it can be further beneficial towards the HF-induced myopathy. However, there is limited evidence regarding the exercise type that elicits optimum angiogenic responses of skeletal muscle in HF patients. This study aimed to (a) compare the effects of a high-intensity-interval-training (HIIT) or combined HIIT with strength training (COM) exercise protocol on the expression of angiogenesis-related factors in skeletal muscle of HF patients, and (b) examine the potential associations between the expression of those genes and capillarization in the trained muscles. Thirteen male patients with chronic HF (age: 51 ± 13 y; BMI: 27 ± 4 kg/m2) were randomly assigned to a 3-month exercise program that consisted of either HIIT (N = 6) or COM training (N = 7). Vastus lateralis muscle biopsies were performed pre- and post-training. RT-PCR was used to quantify the fold changes in mRNA expression of vascular endothelial growth factor (VEGF), vascular endothelial growth factor receptor 2 (VEGFR-2), hypoxia-inducible factor 1 alpha (HIF-1α), angiopoietin 1 (Ang-1), angiopoietin 2 (Ang-2), angiopoietin receptor (Tie2), and matrix metallopeptidase 9 (MMP-9), and immunohistochemistry to assess capillarization in skeletal muscle post-training. There was an overall increase in the expression levels of VEGF, VEGFR-2, HIF-1α, Ang2, and MMP9 post-training, while these changes were not different among groups. Changes in capillary-to-fibre ratio were found to be strongly associated with Tie2 and HIF-1α expression. This was the first study demonstrating that both HIIT and combined HIIT with strength training enhanced similarly the expression profile of angiogenic factors in skeletal muscle of HF patients, possibly driving the angiogenic program in the trained muscles, although those gene expression increases were found to be only partially related with muscle capillarization.

Cardiac Rehabilitation in German Speaking Countries of Europe-Evidence-Based Guidelines from Germany, Austria and Switzerland LLKardReha-DACH-Part 2

Background: Scientific guidelines have been developed to update and harmonize exercise based cardiac rehabilitation (ebCR) in German speaking countries. Key recommendations for ebCR indications have recently been published in part 1 of this journal. The present part 2 updates the evidence with respect to contents and delivery of ebCR in clinical practice, focusing on exercise training (ET), psychological interventions (PI), patient education (PE). In addition, special patients’ groups and new developments, such as telemedical (Tele) or home-based ebCR, are discussed as well. Methods: Generation of evidence and search of literature have been described in part 1. Results: Well documented evidence confirms the prognostic significance of ET in patients with coronary artery disease. Positive clinical effects of ET are described in patients with congestive heart failure, heart valve surgery or intervention, adults with congenital heart disease, and peripheral arterial disease. Specific recommendations for risk stratification and adequate exercise prescription for continuous-, interval-, and strength training are given in detail. PI when added to ebCR did not show significant positive effects in general. There was a positive trend towards reduction in depressive symptoms for “distress management” and “lifestyle changes”. PE is able to increase patients’ knowledge and motivation, as well as behavior changes, regarding physical activity, dietary habits, and smoking cessation. The evidence for distinct ebCR programs in special patients’ groups is less clear. Studies on Tele-CR predominantly included low-risk patients. Hence, it is questionable, whether clinical results derived from studies in conventional ebCR may be transferred to Tele-CR. Conclusions: ET is the cornerstone of ebCR. Additional PI should be included, adjusted to the needs of the individual patient. PE is able to promote patients self-management, empowerment, and motivation. Diversity-sensitive structures should be established to interact with the needs of special patient groups and gender issues. Tele-CR should be further investigated as a valuable tool to implement ebCR more widely and effectively.

A systematic review of rehabilitation in chronic heart failure: evaluating the reporting of exercise interventions

A large body of research supports the use of exercise to improve symptoms, quality of life, and physical function in patients with chronic heart failure. Previous reviews have focused on reporting outcomes of exercise interventions such as cardiorespiratory fitness. However, none have critically examined exercise prescription. The aim of this review was to evaluate the reporting and application of exercise principles in randomised control trials of exercise training in patients with chronic heart failure. A systematic review of exercise intervention RCTs in patients with CHF, using the Consensus on Exercise Reporting Template (CERT), was undertaken. The Ovid Medline/PubMed, Embase, Scopus/Web of Science, and Cochrane Library and Health Technology Assessment Databases were searched from 2000 to June 2020. Prospective RCTs in which patients with CHF were randomized to a structured exercise programme were included. No limits were placed on the type or duration of exercise structured exercise programme or type of CHF (i.e. preserved or reduced ejection fraction). We included 143 studies, comprising of 181 different exercise interventions. The mean CERT score was 10 out of 19, with no study achieving a score of 19. Primarily, details were missing regarding motivational strategies, home-based exercise components, and adherence/fidelity to the intervention. Exercise intensity was the most common principle of exercise prescription missing from intervention reporting. There was no improvement in the reporting of exercise interventions with time (R²  = 0.003). Most RCTs of exercise training in CHF are reported with insufficient detail to allow for replication, limiting the translation of evidence to clinical practice. We encourage authors to provide adequate details when reporting future interventions. Where journal word counts are restrictive, we recommend using supplementary material or publishing trial protocols prior to beginning the study.

Combined aerobic and strength training for fitness outcomes in heart failure: meta-analysis and meta-regression

PURPOSE

To compare the effects of combined training (CT) versus aerobic training (AT) or versus control on VO₂ peak and quadriceps muscle strength in patients with heart failure (HF).

MATERIALS AND METHODS

Major electronic databases were searched, from inception to November 2020, for randomized clinical trials comparing the effects of CT against AT or control on VO₂ peak and/or quadriceps muscle strength in patients with HF. Random effects meta-analyses were conducted, calculating the standardized mean difference (SMD).

RESULTS

Twenty-eight articles were included. An increase on VO₂ peak (SMD = 0.77, 95%CI 0.39-1.14, I²=80.1%) and quadriceps muscle strength (SMD = 0.67, 95%CI 0.18-1.16, I²=0%) was found in CT compared to control. CT increased quadriceps muscle strength, versus AT (SMD = 0.44, 95%CI 0.15-0.74, I²=0%). There were no differences between CT and AT on VO₂ peak (SMD=-0.01, 95%CI -0.36 to 0.34, I²=65%). Time of session and training duration moderate the effects of CT over control on VO₂ peak.

CONCLUSIONS

CT promotes increases on quadriceps muscle strength and aerobic capacity over control and provides additional gains on quadriceps muscle strength, having the same effects on VO₂ peak compared to AT. A longer time of session is associated with greater benefits to aerobic capacity.Implications for rehabilitationCombining aerobic and strength training increases the functional capacity and quadriceps muscle strength in heart failure patients.Using longer sessions of training has a greater impact on aerobic capacity.

Combined aerobic/resistance/inspiratory muscle training as the 'optimum' exercise programme for patients with chronic heart failure: ARISTOS-HF randomized clinical trial

AIMS

An 'optimum' universally agreed exercise programme for heart failure (HF) patients has not been found. ARISTOS-HF randomized clinical trial evaluates whether combined aerobic training (AT)/resistance training (RT)/inspiratory muscle training (IMT) (ARIS) is superior to AT/RT, AT/IMT or AT in improving aerobic capacity, left ventricular dimensions, and secondary functional outcomes.

METHODS AND RESULTS

Eighty-eight patients of New York Heart Association II-III, left ventricular ejection fraction  ≤ 35% were randomized to an ARIS, AT/RT, AT/IMT, or AT group, exercising 3 times/week, 180 min/week for 12 weeks. Pre- and post-training, peakVO2 was evaluated with cardiopulmonary exercise testing, left ventricular dimensions using echocardiography, walking distance with the 6-min walk test (6MWT), quality of life by the Minnesota Living with HF Questionnaire (MLwHFQ), while a programme preference survey (PPS) was used. Seventy-four patients of [mean 95% (confidence interval, CI)] age 66.1 (64.3-67.9) years and peakVO2 17.3 (16.4-18.2) mL/kg/min were finally analysed. Between-group analysis showed a trend for increased peakVO2 (mL/kg/min) [mean contrasts (95% CI)] in the ARIS group [ARIS vs. AT/RT 1.71 (0.163-3.25)(.), vs. AT/IMT 1.50 (0.0152-2.99)(.), vs. AT 1.38 (-0.142 to 2.9)(.)], additional benefits in circulatory power (mL/kg/min⋅mmHg) [ARIS vs. AT/RT 376 (60.7-690)*, vs. AT/IMT 423 (121-725)*, vs. AT 345 (35.4-656)*], left ventricular end-systolic diameter (mm) [ARIS vs. AT/RT -2.11 (-3.65 to (-0.561))*, vs. AT -2.47 (-4.01 to (-0.929))**], 6MWT (m) [ARIS vs. AT/IMT 45.6 (18.3-72.9)**, vs. AT 55.2 (27.6-82.7)****], MLwHFQ [ARIS vs. AT/RT -7.79 (-11 to (-4.62))****, vs. AT -8.96 (-12.1 to (-5.84))****], and in PPS score [mean (95% CI)] [ARIS, 4.8 (4.7-5) vs. AT, 4.4 (4.2-4.7)*] [(.) P ≤ 0.1; *P ≤ 0.05; **P ≤ 0.01; ***P ≤ 0.001; ****P ≤ 0.0001].

CONCLUSION

ARISTOS-HF trial recommends exercise training for 180 min/week and supports the prescription of the ARIS training regime for HF patients (Clinical Trial Registration: http://www.clinicaltrials.gov. ARISTOS-HF Clinical Trial number, NCT03013270).

Physical Therapist Clinical Practice Guideline for the Management of Individuals With Heart Failure

The American Physical Therapy Association (APTA), in conjunction with the Cardiovascular and Pulmonary Section of APTA, have commissioned the development of this clinical practice guideline to assist physical therapists in their clinical decision making when managing patients with heart failure. Physical therapists treat patients with varying degrees of impairments and limitations in activity and participation associated with heart failure pathology across the continuum of care. This document will guide physical therapist practice in the examination and treatment of patients with a known diagnosis of heart failure. The development of this clinical practice guideline followed a structured process and resulted in 9 key action statements to guide physical therapist practice. The level and quality of available evidence were graded based on specific criteria to determine the strength of each action statement. Clinical algorithms were developed to guide the physical therapist in appropriate clinical decision making. Physical therapists are encouraged to work collaboratively with other members of the health care team in implementing these action statements to improve the activity, participation, and quality of life in individuals with heart failure and reduce the incidence of heart failure-related re-admissions.

Effect of combined interval training on the cardiorespiratory fitness in heart failure patients: a systematic review and meta-analysis

BACKGROUND

The combination of interval training and resistance training has showed interesting results in chronic heart failure patients, corroborating the benefits of physiological adaptations of both protocols.

OBJECTIVE

To evaluate the effect of the combination of interval training and resistance training program when compared to interval training alone and/or without intervention group on cardiorespiratory fitness in patients with chronic heart failure.

METHODS

We search MEDLINE via PubMed, ScienceDirect, Sportdiscus, BIREME and Scielo, from their inception to December 2018. Were included both randomized and non-randomized controlled trials comparing the effect of combined training, interval training alone and/or WI group on VO2peak (expressed in ml/kg/min), in people with chronic heart failure patients. The meta-analysis was conducted via Review Manager v 5.3 software, using random effect model.

RESULTS

Ten articles were selected (nine randomized controlled trial), involving 401 participants. Six studies compared combined training with interval training and six studies compared combined training with the without intervention group. Eighty percent of the trials presented moderate risk of bias and twenty percent low risk of bias. Data showed significant difference and major increase in VO2peak in favor to combined training group compared to interval training group (SMD=0.25; CI=0.04-0.46) and without intervention group (SMD=0.46; CI=0.29-0.64), respectively.

CONCLUSION

The combination of interval training and resistance training showed more effective in increasing cardiorespiratory fitness in patients with heart failure than interval training alone and non-exercise therapy. However, further studies should be conducted to increase the understanding of this combined training method.

Exercise as a prescription for patients with various diseases

A growing understanding of the benefits of exercise over the past few decades has prompted researchers to take an interest in the possibilities of exercise therapy. Because each sport has its own set of characteristics and physiological complications that tend to occur during exercise training, the effects and underlying mechanisms of exercise remain unclear. Thus, the first step in probing the effects of exercise on different diseases is the selection of an optimal exercise protocol. This review summarizes the latest exercise prescription treatments for 26 different diseases: musculoskeletal system diseases (low back pain, tendon injury, osteoporosis, osteoarthritis, and hip fracture), metabolic system diseases (obesity, type 2 diabetes, type 1 diabetes, and nonalcoholic fatty liver disease), cardio-cerebral vascular system diseases (coronary artery disease, stroke, and chronic heart failure), nervous system diseases (Parkinson's disease, Huntington's disease, Alzheimer's disease, depression, and anxiety disorders), respiratory system diseases (chronic obstructive pulmonary disease, interstitial lung disease, and after lung transplantation), urinary system diseases (chronic kidney disease and after kidney transplantation), and cancers (breast cancer, colon cancer, prostate cancer, and lung cancer). Each exercise prescription is displayed in a corresponding table. The recommended type, intensity, and frequency of exercise prescriptions are summarized, and the effects of exercise therapy on the prevention and rehabilitation of different diseases are discussed.

Blood Flow Restriction Resistance Exercise Improves Muscle Strength and Hemodynamics, but Not Vascular Function in Coronary Artery Disease Patients: A Pilot Randomized Controlled Trial

Resistance training may be associated with unfavorable cardiovascular responses (such as hemodynamic alterations, anginal symptoms or ventricular arrhythmias). In healthy adults, blood flow-restricted (BFR) resistance training improves muscle strength and hypertrophy improvements at lower loads with minimal systemic cardiovascular adverse responses. The aim of this study was to assess the safety and efficacy of BFR resistance training in patients with coronary artery disease (CAD) compared to usual care. Patients with stable CAD were randomized to either 8 weeks of supervised biweekly BFR resistance training (30-40% 1RM unilateral knee extension) or usual exercise routine. At baseline and after 8 weeks, patients underwent 1-RM knee extension tests, ultrasonographic appraisal of vastus lateralis (VL) muscle diameter and of systemic (brachial artery) flow-mediated dilation, and determination of markers of inflammation (CD40 ligand and tumor necrosis factor alfa), and fasting glucose and insulin levels for homeostatic model assessment (HOMA). A total of 24 patients [12 per group, mean age 60 ± 2 years, 6 (25%) women] were included. No training-related adverse events were recorded. At baseline groups significantly differ in age (mean difference: 8.7 years, p < 0.001), systolic blood pressure (mean difference: 12.17 mmHg, p = 0.024) and in metabolic control [insulin (p = 0.014) and HOMA IR (p = 0.014)]. BFR-resistance training significantly increased muscle strength (1-RM, +8.96 kg, p < 0.001), and decreased systolic blood pressure (-6.77 mmHg; p = 0.030), whereas VL diameter (+0.09 cm, p = 0.096), brachial artery flow-mediated vasodilation (+1.55%; p = 0.079) and insulin sensitivity (HOMA IR change of 1.15, p = 0.079) did not improve significantly. Blood flow restricted resistance training is safe and associated with significant improvements in muscle strength, and may be therefore provided as an additional exercise option to aerobic exercise to improve skeletal muscle functioning in patients with CAD. Clinical Trial Registration: www.ClinicalTrials.gov, identifier: NCT03087292.

Resistance exercise enhances oxygen uptake without worsening cardiac function in patients with systolic heart failure: a systematic review and meta-analysis

Recent literature suggests that resistance training (RT) improves peak oxygen uptake ([Formula: see text] peak), similarly to aerobic exercise (AE) in patients with heart failure (HF), but its effect on cardiac remodeling is controversial. Thus, we examined the effects of RT and AE on [Formula: see text] peak and cardiac remodeling in patients with heart failure (HF) via a systematic review and meta-analysis. MEDLINE, EMBASE, Cochrane Library and CINAHL, AMEDEO and PEDro databases search were extracted study characteristics, exercise type, and ventricular outcomes. The main outcomes were [Formula: see text] peak (ml kg^-1 min^-1), LVEF (%) and LVEDV (mL). Fifty-nine RCTs were included. RT produced a greater increase in [Formula: see text] peak (3.57 ml kg^-1 min^-1, P < 0.00001, I ² = 0%) compared to AE (2.63 ml kg^-1 min^-1, P < 0.00001, I ² = 58%) while combined RT and AE produced a 2.48 ml kg^-1 min^-1 increase in [Formula: see text]; I ² = 69%) compared to control group. Comparison among the three forms of exercise revealed similar effects on [Formula: see text] peak (P = 0.84 and 1.00, respectively; I ² = 0%). AE was associated with a greater gain in LVEF (3.15%; P < 0.00001, I ² = 17%) compared to RT alone or combined exercise which produced similar gains compared to control groups. Subgroup analysis revealed that AE reduced LVEDV (- 10.21 ml; P = 0.007, I ² = 0%), while RT and combined RT and AE had no effect on LVEDV compared with control participants. RT results in a greater gain in [Formula: see text] peak, and induces no deleterious effects on cardiac function in HF patients.

The ‘aerobic/resistance/inspiratory muscle training hypothesis in heart failure’

Evidence from large multicentre exercise intervention trials in heart failure patients, investigating both moderate continuous aerobic training and high intensity interval training, indicates that the ‘crème de la crème’ exercise programme for this population remains to be found. The ‘aerobic/resistance/inspiratory (ARIS) muscle training hypothesis in heart failure’ is introduced, suggesting that combined ARIS muscle training may result in maximal exercise pathophysiological and functional benefits in heart failure patients. The hypothesis is based on the decoding of the ‘skeletal muscle hypothesis in heart failure’ and on revision of experimental evidence to date showing that exercise and functional intolerance in heart failure patients are associated not only with reduced muscle endurance, indication for aerobic training (AT), but also with reduced muscle strength and decreased inspiratory muscle function contributing to weakness, dyspnoea, fatigue and low aerobic capacity, forming the grounds for the addition of both resistance training (RT) and inspiratory muscle training (IMT) to AT. The hypothesis will be tested by comparing all potential exercise combinations, ARIS, AT/RT, AT/IMT, AT, evaluating both functional and cardiac indices in a large sample of heart failure patients of New York Heart Association class II–III and left ventricular ejection fraction ≤35% ad hoc by the multicentre randomized clinical trial, Aerobic Resistance, InSpiratory Training OutcomeS in Heart Failure (ARISTOS-HF trial).

Exercise for Preventing Hospitalization and Readmission in Adults With Congestive Heart Failure

We critically appraised all available evidence regarding exercise interventions for improving patient survival and reducing hospital admissions in adults with chronic heart failure (HF). We searched 4 databases up to April 2018 and graded the quality of evidence according to the Grading of Recommendations Assessment, Development and Evaluation working group approach. We reviewed 7 meta-analyses and the publications of 48 randomized controlled trials (RCTs). In HF with reduced ejection fraction, low-quality evidence suggests that exercise prevents all-cause hospitalizations [Relative risk (RR), 0.77; 95% confidence interval (CI), 0.63 to 0.93; 1328 patients in 15 RCTs] and hospitalizations due to HF (RR, 0.57; 95% CI, 0.37 to 0.88; 1073 patients in 13 RCTs) and improves quality of life (standardized mean difference, -0.37; 95% CI, -0.60 to -0.14; 1270 patients in 25 RCTs) but has no effect on mortality. In HF with preserved ejection fraction, low-quality evidence suggests that exercise improves peak oxygen uptake (mean difference, 2.36; 95% CI, 1.16 to 3.57; 171 patients in 3 RCTs) and quality of life (mean difference, -4.65; 95% CI, -8.46 to -0.83; 203 patients in 4 RCTs). In patients after heart transplantation, low-quality evidence suggests that exercise improves peak oxygen uptake (standardized mean difference, 0.68; 95% CI, 0.43 to 0.93; 284 patients in 9 RCTs) but does not improve quality of life. In order to reduce hospitalization and improve quality of life for adults with HF and reduced ejection fraction, clinicians should recommend exercise interventions. For adults with HF and preserved ejection fraction and in those undergoing heart transplantation, clinicians may recommend exercise interventions in order to improve peak oxygen uptake.

The Effects of Exercise Training on Brachial Artery Flow-Mediated Dilation: A Meta-analysis

PURPOSE

Flow-mediated dilation, a barometer of cardiovascular (CV) health, is reported to increase with exercise training (ET); however, the potential moderating factors of ET are not clear to date. The purpose of this study was to determine the effect of ET assessed by brachial artery flow-mediated dilation (BAFMD).

METHODS

Authors searched PubMed between January 1999 and December 2013, bibliographies, and reviews to identify studies examining ET and BAFMD. Two independent reviewers extracted quality, descriptive, exercise, and outcome data of eligible studies. Data were presented as weighted effect sizes (ESs) and 95% confidence limits.

RESULTS

Analysis included 66 studies reporting BAFMD data (1865 ET and 635 control subjects). Overall, ET had significant improvements in BAFMD compared with controls (P < .0001). Exercise training at higher ET intensities resulted in a greater increase in BAFMD (9.29; 95% CI, 5.09-13.47) than lower ET intensities (3.63; 95% CI, -0.56 to 7.83) or control (-0.42; 95% CI, -2.06 to 1.21). Subjects whose ET duration was ≥150 min/wk (11.33; 95% CI, 7.15-15.51) had a significant improvement in BAFMD compared with those with <150 min/wk (4.79; 95% CI, 3.08-6.51) or control (-0.30; 95% CI, -1.99 to 1.39). Age (P = .11) and baseline artery diameter (P = .31) did not modify the BAFMD response to ET.

CONCLUSION

Exercise training contributes to a significant increase in BAFMD. These results provide indirect evidence that ET alters a well-known factor associated with the primary and secondary prevention of CV diseases. Exercise training interventions, including greater intensity and duration, may optimize the increase in BAFMD.

Exercise training improves characteristics of exercise oscillatory ventilation in chronic heart failure

Background Exercise oscillatory ventilation in chronic heart failure has been suggested as a factor related to adverse cardiac events, aggravated prognosis and higher mortality. Exercise training is well known to affect exercise capacity and mechanisms of pathophysiology beneficially in chronic heart failure. Little is known, however, about the exercise training effects on characteristics of exercise oscillatory ventilation in chronic heart failure patients. Design and methods Twenty (out of 38) stable chronic heart failure patients exhibited exercise oscillatory ventilation (age 54 ± 11 years, peak oxygen uptake 15.0 ± 5.0 ml/kg per minute). Patients attended 36 sessions of high intensity interval exercise. All patients underwent cardiopulmonary exercise testing before and after the programme. Assessment of exercise oscillatory ventilation was based on the amplitude of cyclic fluctuations in breathing during rest and exercise. All values are mean ± SD. Results Exercise training reduced ( P < 0.05) the percentage of exercise oscillatory ventilation duration (79.0 ± 13.0 to 50.0 ± 25.0%), while average amplitude (5.2 ± 2.0 to 4.9 ± 1.6 L/minute) and length (44.0 ± 10.9 to 41.0 ± 6.7 seconds) did not change ( P > 0.05). Exercise oscillatory ventilation patients also increased exercise capacity ( P < 0.05). Conclusions A rehabilitation programme based on high intensity interval training improved exercise oscillatory ventilation observed in chronic heart failure patients, as well as cardiopulmonary efficiency and functional capacity.

Aerobic Training Intensity for Improved Endothelial Function in Heart Failure Patients: A Systematic Review and Meta-Analysis

Objective. Flow-mediated dilation (FMD) is widely utilised to assess endothelial function and aerobic exercise improves FMD in heart failure patients. The aim of this meta-analysis is to quantify the effect of aerobic training intensity on FMD in patients with heart failure. Background. A large number of studies now exist that examine endothelial function in patients with heart failure. We sought to add to the current literature by quantifying the effect of the aerobic training intensity on endothelial function. Methods. We conducted database searches (PubMed, Embase, ProQuest, and Cochrane Trials Register to June 30, 2016) for exercise based rehabilitation trials in heart failure, using search terms exercise training, endothelial function, and flow-mediated dilation (FMD). Results. The 13 included studies provided a total of 458 participants, 264 in intervention groups, and 194 in nonexercising control groups. Both vigorous and moderate intensity aerobic training significantly improved FMD. Conclusion. Overall both vigorous and moderate aerobic exercise training improved FMD in patients with heart failure.

Effects of High-Intensity Interval Exercise Training on Skeletal Myopathy of Chronic Heart Failure

BACKGROUND

It remains controversial which type of exercise elicits optimum adaptations on skeletal myopathy of heart failure (HF). Our aim was to evaluate the effect of high-intensity interval training (HIIT), with or without the addition of strength training, on skeletal muscle of HF patients.

METHODS AND RESULTS

Thirteen male HF patients (age 51 ± 13 years, body mass index 27 ± 4 kg/m²) participated in either an HIIT (AER) or an HIIT combined with strength training (COM) 3-month program. Biopsy samples were obtained from the vastus lateralis. Analyses were performed on muscle fiber type, cross-section area (CSA), capillary density, and mRNA expression of insulin-like growth factor (IGF) 1 isoforms (ie, IGF-1Ea, IGF-1Eb, IGF-1Ec), type-1 receptor (IGF-1R), and binding protein 3 (IGFBP-3). Increased expression of IGF-1Ea, IGF-1Eb, IGF-1Ec, and IGFBP-3 transcripts was found (1.7 ± 0.8, 1.5 ± 0.8, 2.0 ± 1.32.4 ± 1.4 fold changes, respectively; P < .05). Type I fibers increased by 21% (42 ± 10% to 51 ± 7%; P < .001) and capillary/fiber ratio increased by 24% (1.27 ± 0.22 to 1.57 ± 0.41; P = .005) in both groups as a whole. Fibers' mean CSA increased by 10% in total, but the increase in type I fibers' CSA was greater after AER than COM (15% vs 6%; P < .05). The increased CSA correlated with the increased expression of IGF-1Ea and IGF-1Εb.

CONCLUSIONS

HIIT reverses skeletal myopathy of HF patients, with the adaptive responses of the IGF-1 bioregulation system possibly contributing to these effects. AER program seemed to be superior to COM to induce muscle hypertrophy.

Comparing exercise training modalities in heart failure: A systematic review and meta-analysis

Exercise training (ET) is suggested to improve exercise capacity, prognosis, quality of life (QOL) and functional modifications of the heart in patients with heart failure (HF). However, it is not clear which modality is best. In order to assess the effectiveness of different ET modalities on prognostic cardiopulmonary exercise test (CPET) parameters, QOL and left ventricular remodeling, a systematic review and meta-analysis was performed. Randomized clinical trials (RCTs) were selected in three databases. The primary outcome data were peak oxygen uptake, ventilation over carbon dioxide slope, oxygen uptake efficiency slope, exercise oscillatory ventilation, rest and peak pulmonary end-tidal CO2. Secondary variables were QOL, left ventricular ejection fraction (LVEF) and left ventricular end-diastolic diameter (LVEDD). Twenty RCTs (n=811) met the a priori stated inclusion criteria. Studies were categorized into four different groups: "interval training (IT1) versus combined interval and strength training (IT1S)" (n=156), "continuous training (CT1) versus combined continuous and strength training (CT1S)" (n=130), "interval training (IT2) versus continuous training (CT2)" (n=501) and "continuous training (CT3) versus strength training (S3)" (n=24). No significant random effects of exercise modality were revealed assessing the CPET parameters. There was a significant improvement in QOL applying CT1S (P<0.001). Comparing IT2 with CT2, LVEDD and LVEF were significantly improved favoring IT2 (P<0.001). There is some evidence to support that interval training is more effective to improve LVEF and LVEDD. The fact that patients with HF are actively involved in any kind of ET program seems sufficient to improve the prognosis, QOL and anatomic function.

[Exercise-induced shear stress: Physiological basis and clinical impact]

The physiological regulation of vascular function is essential for cardiovascular health and depends on adequate control of molecular mechanisms triggered by endothelial cells in response to mechanical and chemical stimuli induced by blood flow. Endothelial dysfunction is one of the major risk factors for cardiovascular disease, where an imbalance between synthesis of vasodilator and vasoconstrictor molecules is one of its main mechanisms. In this context, the shear stress is one of the most important mechanical stimuli to improve vascular function, due to endothelial mechanotransduction, triggered by stimulation of various endothelial mechanosensors, induce signaling pathways culminating in increased bioavailability of vasodilators molecules such as nitric oxide, that finally trigger the angiogenic mechanisms. These mechanisms allow providing the physiological basis for the effects of exercise on vascular health. In this review it is discussed the molecular mechanisms involved in the vascular response induced by shear stress and its impact in reversing vascular injury associated with the most prevalent cardiovascular disease in our population.

Attenuated Microcirculatory Response to Maximal Exercise in Patients With Chronic Heart Failure

PURPOSE

Exercise training programs improve microcirculatory alternations in patients with chronic heart failure (CHF). However less is known about the acute effect of maximum exercise on the skeletal muscle microcirculation. We aimed to assess the effect of acute exercise on peripheral microcirculation of patients with CHF, as assessed by near-infrared spectroscopy with vascular occlusion technique.

METHODS

Tissue oxygenation was evaluated in 8 stable patients with CHF (7 males; mean age, 60 ± 9 years; body mass index, 26.3 ± 3.8 kg/m) and 8 healthy subjects (matched for age, sex, and body mass index) before and after cardiopulmonary exercise testing. Tissue oxygen saturation (StO2), StO2peak, oxygen consumption rate, and endothelial function (reperfusion rate), before and after maximum exercise, were assessed.

RESULTS

Patients with CHF had lower StO2 and reperfusion rate compared with healthy subjects (71.4% ± 9.8% vs 81.0% ± 5.4% and 9 ± 1 %/min vs 13.9 ± 5.8%/min, respectively; P < .05) at rest. Oxygen consumption rate increased after exercise in patients with CHF and healthy subjects (from -31.7 ± 8.2 to -43.7 ± 12.7 and from -35.7 ± 6.7 to -42.4 ± 6.4, respectively; P < .05). StO2 decreased significantly after maximal exercise in patients with CHF (from 71.4 ± 9.8 to 65.2 ± 12.7; P < .05), whereas it returned to the preexercise values in healthy subjects (from 81.0 ± 5.4 to 80.3 ± 7.0). There was a significant between-group difference (P < .05).

CONCLUSIONS

Patients with CHF present microcirculatory alternations. Acute exercise exerts an effect on microcirculation in peripheral, nonexercising muscles, with altered response in patients with CHF compared with healthy subjects.

EFEITOS DO TREINAMENTO FÍSICO NO ENDOTÉLIO APÓS CIRURGIA DE REVASCULARIZAÇÃO

Introdução A cirurgia de revascularização do miocárdio (CRM) é uma das mais frequentes cirurgias realizadas em todo o mundo, muitos estudos vêm relatando os benefícios do treinamento físico para a melhora da capacidade funcional, porém há poucos estudos sobre os efeitos na função endotelial vascular. Objetivo Analisar os efeitos do treinamento físico sobre a função endotelial vascular em pacientes submetidos à CRM, isoladamente na fase tardia da reabilitação após seis meses de programa de reabilitação cardíaca (PCR). Métodos Foram incluídos pacientes que haviam sido submetidos à CRM no período máximo de um ano após a cirurgia. O PRC foi empregado durante seis meses consecutivos, com três sessões semanais. Todos os pacientes realizaram exames laboratoriais, teste de força muscular de uma repetição máxima (1-RM) para os membros superiores e inferiores, teste de caminhada de 6 min (TC6M) e avaliação da função endotelial através da técnica de vasodilatação mediada pelo fluxo. Resultados Onze pacientes iniciaram o PRC, porém nove pacientes o completaram. A média de idade foi de 66 anos (50 a 82 anos) e o sexo masculino foi predominante (55,6%). Houve mudanças significativas nos exames laboratoriais bioquímicos: aumento do colesterol total (Basal: 162 ± 31mg/dL vs. 195 ± 39mg/dL; P=0,012) e diminuição da hemoglobina glicada (Basal: 6,74 ± 1,64% vs. 6,26 ± 1,62%; P=0,028). A força muscular aumentou significativamente nos membros superiores e inferiores (P=0,030 e P=0,038, respectivamente); no TC6M observou-se um aumento significativo de 20% na distância percorrida (P=0,020) após seis meses consecutivos de treinamento e houve uma melhora na vasodilatação mediada pelo fluxo (Basal: 6,35 ± 3,92% vs. 6 meses: 9,90 ± 4,19%; P=0,026). Conclusão O treinamento combinado realizado em seis meses ajudou a melhorar a função endotelial e a capacidade funcional de pacientes sedentários que foram submetidos à CRM na fase tardia da reabilitação.

Effect of Segment-Body Vibration on Strength Parameters

Background

In this study, we examine the biomechanical advantage of combining localized vibrations to hamstring muscles involved in a traditional resistance training routine.

Methods

Thirty-six male and female participants with at least 2 years of experience in resistance training were recruited from the German Sport University Cologne. The participants were randomized into two training groups: vibration training group (VG) and traditional training group (TTG). Both groups underwent a 4-week training phase, where each participant worked out at 70 % of the individual 1 repeat maximum (RM—maximum load capacity of a muscle for one lift to fatigue) (4 sets with 12 repetitions each). For participants in the VG group, local vibration was additionally applied directly to hamstring muscles during exercise. A 2-week examination phase preceded the pretests. After the pretests, the subjects underwent a prescribed training for 4 weeks. At the conclusion of the training, a 2-week detraining was imposed and then the study concluded with posttests and retest.

Results

The measured parameters were maximum isometric force of the hamstrings and maximum range of motion and muscle tension at maximum knee angle. The study revealed a significant increase in maximum isometric force in both training groups (VG = 21 %, TTG = 14 %). However, VG groups showed an increase in their range of motion by approximately 2 %. Moreover, the muscle tension at maximum knee angle increased less in VG (approximately 35 %) compared to TG (approximately 46 %).

Conclusions

We conclude that segment-body vibrations applied in resistance training can offer an effective tool to increase maximum isometric force, compared to traditional training. The cause for these findings can be attributed to the additional local vibration stimulus.

Beneficial effects of combined exercise training on early recovery cardiopulmonary exercise testing indices in patients with chronic heart failure

PURPOSE

Exercise training induces several beneficial effects in patients with chronic heart failure (CHF). This study investigated the effects of high-intensity aerobic interval training (AIT) compared with combined AIT and strength training (COM) on early ventilatory and metabolic recovery pattern after symptom-limited cardiopulmonary exercise testing (CPET) in CHF patients.

METHODS

Stable CHF patients (N = 42; 54 ± 10 years [mean ± SD], 35 males) participated in an exercise training program for 12 weeks, 3 times per week. Participants were randomly assigned to either AIT (n = 20) or COM group (n = 22). Cardiopulmonary exercise testing was performed before and after completion of the program. Primary measurements included absolute and percentage difference of oxygen uptake, carbon dioxide output, minute ventilation ((Equation is included in full-text article.)E), tidal volume (VT), respiratory rate, and the first-degree slope of oxygen uptake ((Equation is included in full-text article.)O2/t slope) and carbon dioxide output ((Equation is included in full-text article.)CO2/t slope) during the first minute of recovery after maximal exercise.

RESULTS

The COM group had a greater improvement in the absolute and the percentage difference of (Equation is included in full-text article.)E (P = .03 and P = .04, respectively) and respiratory rate (P = .02 and P = .01, respectively) during the first minute of recovery period after exercise compared with the AIT group alone. No significant changes were noted for VT measurements. A significant increase in (Equation is included in full-text article.)CO2/t slope was observed in COM compared with the AIT group (P = .01). There was a trend for a greater increase in (Equation is included in full-text article.)O2/t slope in the COM group (P = .07).

CONCLUSIONS

The addition of strength training to AIT induces significant beneficial effects in terms of ventilatory and metabolic recovery kinetics than AIT alone in CHF patients, possibly indicating greater ventilatory efficiency and metabolic improvement.

The effects of baseline heart rate recovery normality and exercise training protocol on heart rate recovery in patients with heart failure

Objective:

It is unclear which exercise training protocol yields superior heart rate recovery (HRR) improvement in heart failure (HF) patients. Whether baseline HRR normality plays a role in the improvement is unknown. We hypothesized that an exercise training protocol and baseline HRR normality would be factors in altering HRR in HF patients.

Methods:

In this prospective, randomized, controlled and 3 group parallel study, 41 stable HF patients were randomly assigned to 3-times-weekly training sessions for 12 weeks, consisting of i) 30 minutes of interval training (IT) (n=17, 63.7±8.8 years old) versus ii) 30 minutes of continuous training (CT) (n=13, 59.6±6.8 years old) versus iii) no training (CON) (n=11, 60.6±9.9 years old). Each patient had cardiopulmonary exercise testing before and after the training program. Maximum heart rates attained during the test and heart rates at 1 and 2 min (HRR1 and HRR2) during the recovery phase were recorded. Paired samples t-test or Wilcoxon signed-rank test was used for comparisons before and after training. One-way ANOVA or Kruskal-Wallis variance analysis was used for comparisons among groups.

Results:

HRR1 was unchanged after training. HRR2 improved in the IT group after training, and post-training HRR2 values were significantly faster in the IT group than in controls. Both HRR1 and HRR2 was significantly faster, irrespective of exercise protocol in patients with abnormal baseline values after training.

Conclusion:

HRR1 did not improve after training. HRR2 improved only in the IT group. Both HRRs in patients with abnormal baseline values improved after both exercise protocols. IT might be superior to CT in improving HRR2. Baseline HRR might play a role in its response to exercise.

Exercise intolerance in chronic heart failure: the role of cortisol and the catabolic state

Chronic heart failure (CHF) is a complex clinical syndrome leading to exercise intolerance due to muscular fatigue and dyspnea. Hemodynamics fail to explain the reduced exercise capacity, while a significant skeletal muscular pathology seems to constitute the main underlying mechanism for exercise intolerance in CHF patients. There have been proposed several metabolic, neurohormonal and immune system abnormalities leading to an anabolic/catabolic imbalance that plays a central role in the pathogenesis of the wasting process of skeletal muscle myopathy. The impairment of the anabolic axes is associated with the severity of symptoms and the poor outcome in CHF, whereas increased cortisol levels are predictive of exercise intolerance, ventilatory inefficiency and chronotropic incompetence, suggesting a significant contributing mechanism to the limited functional status. Exercise training and device therapy could have beneficial effects in preventing and treating muscle wasting in CHF. However, specific anabolic treatment needs more investigation to prove possible beneficial effects.

High intensity, interval exercise improves quality of life of patients with chronic heart failure: a randomized controlled trial

BACKGROUND

The aim of this study was to evaluate the effect of high intensity, interval exercise on quality of life (QoL) and depression status, in chronic heart failure (CHF) patients.

METHODS

A randomized controlled trial (phase III). Of the 100 consecutive CHF patients (NYHA classes II-IV, ejection fraction ≤ 50%) that were randomly allocated to exercise intervention (n = 50, high-intensity intermittent endurance training 30 s at 100% of max workload, 30 s at rest, for 45 min/day-by-12 weeks) or no exercise advice (n = 50), 72 (exercise group, n = 33, 63 ± 9 years, 88% men, 70% ischemic CHF and control group, n = 39, 56 ± 11 years, 82% men, 70% ischemic CHF) completed the study. QoL was assessed using the validated and translated Minnesota Living with Heart Failure questionnaire. Depressive symptomatology was evaluated using the validated and translated Zung Depression Rating Scale (ZDRS). Maximal oxygen uptake (VO(2max)) and carbon dioxide production (VCO(2max)) were also measured breath-by-breath.

RESULTS

Data analysis demonstrated that in the intervention group MLHFQ score was reduced by 66% (P = 0.003); 6-min-walk distance increased by 13% (P < 0.05), VO(2max) level increased by 31% (P = 0.001), VCO(2max) level increased by 28% (P = 0.001) and peak power output increased by 25% (P = 0.001), as compared with the control group.

CONCLUSION

High intensity, systematic aerobic training, could be strongly encouraged in CHF patients, since it improves QoL, by favorably modifying their fitness level.

Serial assessment of local peripheral vascular function after eccentric exercise

Muscle damage is a common response to unaccustomed eccentric exercise; however, the effects of skeletal muscle damage on local vascular function and blood flow are poorly understood. This study examined serial local vascular responses to flow-mediated (endothelial-dependent) and nitroglycerin-mediated (endothelial-independent) dilation in the brachial artery after strenuous eccentric exercise and serially assessed resting blood flow. Ten healthy males performed 50 maximal eccentric unilateral arm contractions to induce muscle damage to the biceps brachii. Changes in maximal isometric strength and vascular responses were assessed 1, 24, 48, and 96 h after exercise. Mean blood velocities and arterial diameters, measured with Doppler ultrasound, were used to calculate blood flow and shear stress (expressed as area under the curve). Eccentric exercise resulted in impaired maximal isometric strength for up to 96 h (p < 0.001). Reductions in flow-mediated dilation (before exercise, 9.4% ± 2.6%; 1 h after exercise, 5.1% ± 2.2%) and nitroglycerin responses (before exercise, 26.3% ± 6.5%; 1 h after exercise, 20.7% ± 4.7%) were observed in the 1 h after exercise and remained lower for 96 h (p < 0.05). The shear stress response was attenuated immediately after exercise and remained impaired for 48 h (p < 0.05). Resting blood pressure and muscle blood flow remained similar throughout the study. Results suggest that muscle damage from eccentric exercise leads to impaired local endothelial and vascular smooth muscle function. Lower shear stress after exercise might contribute to the observed reduction in flow-mediated dilation responses, but the mechanism responsible for the attenuated endothelial-independent vasodilation remains unclear.

High-intensity aerobic interval exercise in chronic heart failure

Aerobic exercise training is strongly recommended in patients with heart failure (HF) and reduced left ventricular ejection fraction (LVEF) to improve symptoms and quality of life. Moderate-intensity aerobic continuous exercise (MICE) is the best established training modality in HF patients. For about a decade, however, another training modality, high-intensity aerobic interval exercise (HIIE), has aroused considerable interest in cardiac rehabilitation. Originally used by athletes, HIIE consists of repeated bouts of high-intensity exercise interspersed with recovery periods. The rationale for its use is to increase exercise time spent in high-intensity zones, thereby increasing the training stimulus. Several studies have demonstrated that HIIE is more effective than MICE, notably for improving exercise capacity in patients with HF. The aim of the present review is to describe the general principles of HIIE prescription, the acute physiological effects, the longer-term training effects, and finally the future perspectives of HIIE in patients with HF.

The Steep Ramp Test in Dutch white children and adolescents: age- and sex-related normative values

BACKGROUND

The Steep Ramp Test (SRT), a feasible, reliable, and valid exercise test on a cycle ergometer, may be more appealing for use in children in daily clinical practice than the traditional cardiopulmonary exercise test because of its short duration, its resemblance to children's daily activity patterns, and the fact that it does not require respiratory gas analysis.

OBJECTIVE

The aim of the present study was to provide sex- and age-related normative values for SRT performance in Dutch white children and adolescents who were healthy and 8 to 19 years old.

DESIGN

This was a cross-sectional, observational study.

METHODS

A total of 252 Dutch white children and adolescents, 118 boys (mean age=13.4 years, SD=3.0) and 134 girls (mean age=13.4 years, SD=2.9), performed the SRT (work rate increment of 10, 15, or 20 W·10 s(-1), depending on body height) to voluntary exhaustion to assess peak work rate (WRpeak). Normative values are presented as reference centiles developed by use of generalized additive models for location, scale, and shape.

RESULTS

Peak work rate correlated highly with age (r=.915 and r=.811), body mass (r=.870 and r=.850), body height (r=.922 and r=.896), body surface area (r=.906 and r=.885), and fat free mass (r=.930 and r=.902) in boys and girls, respectively. The reference curves demonstrated an almost linear increase in WRpeak with age in boys, even when WRpeak was normalized for body mass. In contrast, absolute WRpeak in girls increased constantly until the age of approximately 13 years, when it started to level off. Peak work rate normalized for body mass in girls showed only a slight increase with age until 14 years of age, when a slight decrease in relative WRpeak was observed.

LIMITATIONS

The sample may not have been entirely representative of the Dutch population.

CONCLUSIONS

The present study provides sex- and age-related normative values for SRT performance in terms of both absolute WRpeak and relative WRpeak, thereby facilitating the interpretation of SRT results by clinicians and researchers.

Should high-intensity-aerobic interval training become the clinical standard in heart failure?

Aerobic exercise training in the heart failure (HF) population is supported by an extensive body of literature. The clinically accepted model for exercise prescription is currently moderate-intensity-aerobic continuous training (MI-ACT). Documented benefits from the literature include improvements in various aspects of physiologic function, aerobic exercise capacity and quality of life while the impact on morbidity and mortality is promising but requires further investigation. Recently, however, a body of evidence has begun to emerge demonstrating high-intensity-aerobic interval training (HI-AIT) can be performed safely with impressive improvements in physiology, functional capacity and quality of life. These initial findings have led some to question the long-standing clinical approach to aerobic exercise training in patients with HF (i.e., MI-ACT), implying it should perhaps be replaced with a HI-AIT model. This is a potentially controversial paradigm shift given the potential increase in adverse event risk associated with exercising at higher intensities, particularly in the HF population where the likelihood of an untoward episode is already at a heightened state relative to the apparently healthy population. The present review therefore addresses key issues related to HI-AIT in the HF population and makes recommendations for future research and current clinical practice.

Effects of exercise interventions on peripheral vascular endothelial vasoreactivity in patients with heart failure with reduced ejection fraction

Changes in vascular function, such as endothelial dysfunction are linked to the progression of heart failure (HF) and poorer outcomes, such as increased hospitalisations. Exercise training may positively influence endothelial function in HF patients with reduced ejection fraction. The aim of this manuscript is to summarise HF studies evaluating the influence of exercise training on endothelial function as measured by flow mediated vasodilation as a primary outcome and to provide recommendations for future research studies designed to improve peripheral vascular function in HF. Databases were searched for studies published between 1995 and December 2011. Two reviewers determined eligibility and extracted information on study characteristics and quality, exercise interventions, and endothelial function. Eleven articles (N=318 HF participants with an ejection fraction <40%) were eligible for full review. Aerobic, resistance, or combined exercise training improved endothelium-dependent vasodilation as measured by ultrasound or plethysmography. There is less evidence supporting improvement in endothelium-independent function with exercise training. Sample sizes were small and predominantly male. Future research is needed to address the best mode and optimal dose of exercise for all patients with HF including women and subgroups with specific co-morbidities.

Circulating endothelial and progenitor cells: Evidence from acute and long-term exercise effects

Circulating bone-marrow-derived cells, named endothelial progenitor cells (EPCs), are capable of maintaining, generating, and replacing terminally differentiated cells within their own specific tissue as a consequence of physiological cell turnover or tissue damage due to injury. Endothelium maintenance and restoration of normal endothelial cell function is guaranteed by a complex physiological procedure in which EPCs play a significant role. Decreased number of peripheral blood EPCs has been associated with endothelial dysfunction and high cardiovascular risk. In this review, we initially report current knowledge with regard to the role of EPCs in healthy subjects and the clinical value of EPCs in different disease populations such as arterial hypertension, obstructive sleep-apnea syndrome, obesity, diabetes mellitus, peripheral arterial disease, coronary artery disease, pulmonary hypertension, and heart failure. Recent studies have introduced the novel concept that physical activity, either performed as a single exercise session or performed as part of an exercise training program, results in a significant increase of circulating EPCs. In the second part of this review we provide preliminary evidence from recent studies investigating the effects of acute and long-term exercise in healthy subjects and athletes as well as in disease populations.

High-intensity interval training in cardiac rehabilitation

High-intensity interval training (HIIT) is frequently used in sports training. The effects on cardiorespiratory and muscle systems have led scientists to consider its application in the field of cardiovascular diseases. The objective of this review is to report the effects and interest of HIIT in patients with coronary artery disease (CAD) and heart failure (HF), as well as in persons with high cardiovascular risk. A non-systematic review of the literature in the MEDLINE database using keywords 'exercise', 'high-intensity interval training', 'interval training', 'coronary artery disease', 'coronary heart disease', 'chronic heart failure' and 'metabolic syndrome' was performed. We selected articles concerning basic science research, physiological research, and randomized or non-randomized interventional clinical trials published in English. To summarize, HIIT appears safe and better tolerated by patients than moderate-intensity continuous exercise (MICE). HIIT gives rise to many short- and long-term central and peripheral adaptations in these populations. In stable and selected patients, it induces substantial clinical improvements, superior to those achieved by MICE, including beneficial effects on several important prognostic factors (peak oxygen uptake, ventricular function, endothelial function), as well as improving quality of life. HIIT appears to be a safe and effective alternative for the rehabilitation of patients with CAD and HF. It may also assist in improving adherence to exercise training. Larger randomized interventional studies are now necessary to improve the indications for this therapy in different populations.

Influence of Gender in the Psychoneuroimmunological Response to Therapeutic Interval Exercise

Interval exercise has been used as an alternative modality to continuous exercise in patients with various conditions. Although interval exercise can improve health status, it may also exert deleterious effects. Few data are available on differences in psychoneuroimmunological response to high-intensity interval exercise, and it is not known whether males and females differ in their responses to a similar physical stress task. The aim of this study was to evaluate the differences between the psychoneuroimmunological responses of healthy active males and females to a high-intensity interval exercise protocol. Fifty healthy active subjects (25 females) underwent 2 exercise protocol sessions at least 2 weeks apart and at the same time of the day. The first session familiarized participants with the protocol. In the second, after a baseline measurement, subjects performed an exercise protocol with a standardized warm-up followed by three 30-s Wingate tests and an active recovery period. Baseline and postintervention data were gathered on the following: Holter electrocardiogram recordings (standard deviation of normal-to-normal interval [SDNN], square root of mean squared differences of successive NN intervals [RMSSD]); heart rate variability (HRV) index; salivary total protein and immunoglobulin A levels; pressure pain thresholds in masseter and upper trapezius muscles; and profile of mood states. After the exercise protocol, mood disturbance was significantly greater in the males than in the females, while the salivary immunoglobulin A level relative to total proteins was significantly lower in the males. These results suggest that high-intensity interval exercise induces a worse psychoneuroimmunological state in males than in females.

Skeletal muscle microcirculatory abnormalities are associated with exercise intolerance, ventilatory inefficiency, and impaired autonomic control in heart failure

BACKGROUND

Several skeletal muscle abnormalities have been identified in patients with chronic heart failure (CHF), including endothelial dysfunction. We hypothesized that skeletal muscle microcirculation, assessed by near-infrared spectroscopy (NIRS), is impaired in CHF patients and is associated with disease severity.

METHODS

Eighty-three stable patients with mild-moderate CHF (72 males, mean age 54 ± 14 years, body mass index 26.7 ± 3.4 kg/m(2)) and 8 healthy subjects, matched for age, gender and body mass index, underwent NIRS with the vascular occlusion technique and cardiopulmonary exercise testing (CPET) evaluation on the same day. Tissue oxygen saturation (StO(2), %), defined as the percentage of hemoglobin saturation in the microvasculature compartments, was measured in the thenar muscle by NIRS before, during and after 3-minute occlusion of the brachial artery. Measurements included StO(2), oxygen consumption rate (OCR, %/min) and reperfusion rate (RR, %/min). All subjects underwent a symptom-limited CPET on a cycle ergometer. Measurements included VO(2) at peak exercise (VO(2)peak, ml/kg/min) and anaerobic threshold (VO(2)AT, ml/kg/min), VE/VCO(2) slope, chronotropic reserve (CR, %) and heart rate recovery (HRR(1), bpm).

RESULTS

CHF patients had significantly lower StO(2) (75 ± 8.2 vs 80.3 ± 6, p < 0.05), lower OCR (32.3 ± 10.4 vs 37.7 ± 5.5, p < 0.05) and lower RR (10 ± 2.8 vs 15.7 ± 6.3, p < 0.05) compared with healthy controls. CHF patients with RR ≥9.5 had a significantly greater VO(2)peak (p < 0.001), VO(2)AT (p < 0.01), CR (p = 0.01) and HRR(1) (p = 0.01), and lower VE/VCO(2) slope (p = 0.001), compared to those with RR <9.5. In a multivariate analysis, RR was identified as an independent predictor of VO(2)peak, VE/VCO(2) slope and HRR(1).

CONCLUSIONS

Peripheral muscle microcirculation, as assessed by NIRS, is significantly impaired in CHF patients and is associated with disease severity.

Intermittent versus continuous exercise training in chronic heart failure: a meta-analysis

INTRODUCTION

We conducted a meta-analysis of randomized, controlled trials of combined strength and intermittent aerobic training, intermittent aerobic training only and continuous exercise training in heart failure patients.

METHODS

A systematic search was conducted of Medline (Ovid) (1950-September 2011), Embase.com (1974-September 2011), Cochrane Central Register of Controlled Trials and CINAHL (1981-September 19 2011). The search strategy included a mix of MeSH and free text terms for the key concepts heart failure, exercise training, interval training and intermittent exercise training.

RESULTS

The included studies contained an aggregate of 446 patients, 212 completed intermittent exercise training, 66 only continuous exercise training, 59 completed combined intermittent and strength training and 109 sedentary controls. Weighted mean difference (MD) in Peak VO2 was 1.04mlkg(-1)min(-1) and (95% C.I.) was 0.42-1.66 (p=0.0009) in intermittent versus continuous exercise training respectively. Weighted mean difference in Peak VO2 was -1.10mlkg(-1)min(-1) (95% C.I.) was -1.83-0.37 p=0.003 for intermittent only versus intermittent and strength (combined) training respectively. In studies reporting VE/VCO2 for intermittent versus control groups, MD was -1.50 [(95% C.I. -2.64, -0.37), p=0.01] and for intermittent versus continuous exercise training MD was -1.35 [(95% C.I. -2.15, -0.55), p=0.001]. Change in peak VO2 was positively correlated with weekly exercise energy expenditure for intermittent exercise groups (r=0.48, p=0.05).

CONCLUSIONS

Combined strength and intermittent exercise appears superior for peak VO2 changes when compared to intermittent exercise of similar exercise energy expenditure.

Exercise as a nonpharmacologic intervention in patients with heart failure

For patients with heart failure (HF), dyspnea and fatigue resulting in diminished exercise tolerance are among the main factors that contribute to decreased social and physical functioning and quality of life. There has long been evidence to suggest that measures of cardiac function, such as ejection fraction and cardiac output, only poorly correlate with a patient's exercise capacity, indicating the involvement of factors other than those impacting central circulation. The lack of a close correlation between central hemodynamics and exercise tolerance has led to investigations into alterations in the periphery, such as abnormalities in vascular endothelial function, hyperactivation of the sympathetic nervous system, and changes in structure and oxidative capacity of skeletal muscle, which are commonly seen in patients with HF. Over the past 2 decades, numerous clinical trials have demonstrated the beneficial impact of exercise training on skeletal muscle energy metabolism, vascular function, and ventilatory capacity, which correlate with improvements in exercise tolerance, hospitalization rates, and quality of life of patients with HF. In accordance with recent guidelines established by the leading cardiology societies in the United States and Europe, physicians are urged to emphasize exercise training for all clinically stable patients with HF using individualized protocols that feature early mobilization after acute exacerbations of the disease and gradual increases in intensity.