Moderate Continuous Exercise Training Research Articles

Impact of high-intensity exercise training (HIIT) versus moderate continuous training (MCT) on skeletal muscle alterations in HFrEF: a substudy of the SMART-EX trial

Abstract Background Skeletal muscle dysfunction contributes to exercise intolerance in chronic heart failure. The randomized multicenter Study of Myocardial Recovery After Exercise Training in Heart Failure (SMART-EX) has shown that high-intensity exercise training (HIIT) but not moderate continuous training (MCT) reduced the left ventricular end diastolic diameter. Both training modalities significantly increased exercise tolerance as determined by cardiopulmonary exercise testing (CPET). However, the underlying molecular alterations within the skeletal muscle with respect to different exercise training modalities are largely unknown. Methods In patients with chronic heart failure with reduced ejection fraction (HFrEF) who participated in the SMART-EX skeletal muscle substudy needle biopsies from the vastus lateralis muscle were performed before and after 12 weeks of supervised HIIT, MCT, or recommendation of regular exercise (RRE) to allow molecular assessment of markers for muscle catabolism, inflammation and energy supply by RT-PCR and western blotting. Echocardiography and CPET were performed in all patients. Changes over time were tested within each group. Results Skeletal muscle biopsies at baseline and follow-up were available in 31 patients (HIIT n=9; MCT n=9; RRE n=13). The majority of patients were male (87%). Median left ventricular ejection fraction was 29%. Median improvement in peak VO2 was 2.0 (IQR -0.4-2.8) in HIIT vs. 1.4 (IQR -0.9-3.4) in MCT vs. 0.0 (IQR -2.9-2.1) ml/min/kg in RRE. This was statistically not significant. HIIT reduced mRNA levels of the E3 ligases of the ubiquitine proteasome system MuRF1 by -72% (p<0.01) and MafBx -45% (p=0.09) with no change in MCT (MuRF1 -31%, p=0.23; MafBx -47%, p=0.21) and RRE (MuRF1 -8%, p=0.20; MafBx -6%, p=0.46). There was no change in mRNA expression of the inflammatory markers interleukin 6 (HIIT 12%; MCT 29%; RRE -35%; n.s.) and TNFα (HIIT -9%; MCT 20%; RRE 27%; n.s.) in either group. The mRNA expression of the mitochondrial F1 subunit of complex V (ATP5F1) significantly increased in HIIT by 14% (p<0.05) with no change in MCT (-3%, p=0.75) and RRE (2%, p=0.76). The mRNA expression of mitochondrial complex I subunits NDUFB8 and NDUFB6 remained unchanged in all groups. Western blot analysis of porin expression, which is a marker of total mitochondrial content, revealed a significant increase in HIIT by 69% (p<0.05) whereas MCT (21%, p=0.18) and RRE (4%, p=0.79) remained unchanged. Conclusion High-intensity interval training in HFrEF for 12 weeks resulted in reduced markers of protein degradation via the ubiquitine proteasome system and increased markers of mitochondrial content and energy supply via mitochondrial complex V whereas moderate continuous exercise training had only minor (non-significant) effects. These molecular changes are probably one reason why exercise capacity improved in patients of the SMART-EX trail.

High-intensity interval training in patients with an implantable cardioverter defibrillator: a randomized controlled study

Abstract Background Exercise is an effective treatment in a broad spectrum of cardiovascular diseases. High-intensity interval training (HIIT) has shown superior effect on cardiorespiratory fitness and equal or superior effect on morbidity and quality of life (QoL) compared to moderate continuous exercise training. However, evidence of the efficacy and risks of HIIT in patients with increased risk of ventricular arrhythmia remains limited. Purpose To evaluate the effects of HIIT on exercise capacity, QoL and burden of ventricular arrhythmias in patients with an implantable cardioverter defibrillator (ICD) with or without cardiac resynchronization therapy. Methods Patients with ischemic or dilated cardiomyopathy and ICD were randomized to a supervised 12-week HIIT program or to a control group continuing their usual exercise routines. HIIT consisted of four 4-minute intervals aiming at 85-95% of maximum heart rate (HRmax), and 3-minute active recovery aiming at 60-70 % of HRmax in between intervals, 3 times a week for 12 weeks. Primary outcomes were exercise capacity measured as peak oxygen uptake (VO2 peak) and QoL assessed with the Short Form 36 (SF-36) questionnaire. Main secondary outcome was the burden of ventricular arrhythmias analysed from remote patient monitoring data. Results Fifty-six patients were included (table 1). Three patients in the HIIT group did not complete the intervention. Two withdrew due to a knee injury and due to fear of SARS-CoV-2 exposure, respectively. One experienced an appropriate shock during exercise and was excluded from further training after clinical consideration. Fifty-three patients completed all follow-up examinations. HIIT significantly increased VO2 peak with 7.0 %, with no changes in the control group (p=0.001) (figure 1A). There was a significant increase in the SF-36 subscale scores on physical functioning (p<0.05), general health (p<0.05) and health change (p=0.001) in the HIIT group compared to the control group (figure 1B). There were no significant differences between groups in number of non-sustained or sustained ventricular tachycardias, anti-tachycardia pacing therapy or ICD shocks. Conclusions In patients with ICD due to ischemic or dilated cardiomyopathy, a supervised 12-week HIIT-program significantly increased VO2 peak and QoL without increasing the burden of ventricular arrhythmias.Table 1:Patient characteristicsFigure 1:Peak oxygen uptake and QoL

Cognitive Impairment Impacts Exercise Effects on Cognition in Multiple Sclerosis.

Purpose: Exercise training reveals high potential to beneficially impact cognitive performance in persons with multiple sclerosis (pwMS). Research indicates that high-intensity interval training (HIIT) has potentially higher effects on physical fitness and cognition compared to moderate continuous exercise. This study (i) compares the effects of a 3-week HIIT and moderate continuous exercise training on cognitive performance and cardiorespiratory fitness of pwMS in an overall analysis and (ii) investigates potential effects based on baseline cognitive status in a subgroup analysis.Methods: Seventy-five pwMS were randomly assigned to an intervention (HIIT: 5 × 1.5-min intervals at 95–100% HRmax, 3 ×/week) or active control group (CG: 24 min continuous exercise at 65% HRmax, 3 ×/week). Cognitive performance was assessed pre- and post-intervention with the Brief International Cognitive Assessment for MS (BICAMS). (I) To examine potential within (time) and interaction (time × group) effects in the overall analysis, separate analyses of covariance (ANCOVA) were conducted. (II) For the subgroup analysis, participants were divided into two groups [intact cognition or impaired cognition (>1.5 standard deviation (SD) compared to healthy, age-matched norm data in at least one of the three tests of the BICAMS]. Potential impacts of cognitive status and intervention were investigated with multivariate analyses of variance (MANOVA).Results: Overall analysis revealed significant time effects for processing speed, verbal learning, rel. VO2peak, and rel. power output. A time*group interaction effect was observed for rel. power output. Subgroup analysis indicated a significant main effect for cognition (impaired cognition vs. intact cognition). Subsequent post-hoc analysis showed significant larger effects on verbal learning in pwMS with impaired cognition.Conclusion: Current results need to be confirmed in a powered randomized controlled trial with cognitive performance as primary endpoint and eligibility based on cognitive performance that is assessed prior to study inclusion.

Weekly Activity Maintained While Adding Training Among Post Bariatric and Obese Participants

It is suggested that a barrier to weight loss during exercise training is associated with increased compensatory sedentary activity (CSA). While studies report a positive association between physical activity and improved weight loss in post bariatric (PB) and obese individuals, the effectiveness for the different types of physical activity interventions and CSA reported is often equivocal. PURPOSE: To evaluate if vigorous or moderate continuous exercise regimens maintain or increase energy expenditure of individuals during exercise training. METHODS: Eight PB individuals [7 female, 1 male; Body Mass Index (BMI) = 34.95 ± 7.6] and ten obese individual [7 female, 3 male; BMI = 38.99 ± 6.5] participated in a supervised 12 week three days per week treadmill exercise training program. The PB high intensity interval group exercised at 80% of their age adjusted heart rate reserve (HRR) for 4 one minute intervals interspersed with 4 minute recovery bouts at 50% of the HRR for weeks 3 through 6. Exercise was increased to 6 one minute bouts at the same HRR intensity and recovery time for weeks 7 through 12. The obese continuous moderate intensity group exercised for 20 minutes at 60% HRR for weeks 3 through 6 and 20 minutes at 65% HRR for weeks 7 through 12. Both exercise interventions included a 2-week run-in to avoid injuries. Energy expenditure (MET-hrs) was measured using micro activPALs for the pre-exercise week and weeks 3, 9 and 12. RESULTS: Overall, there were no significant differences between groups for MET-hrs for any week. MET-hrs increased (p <.05) from the pre-exercise week (212.1 ± 4.96) during the intervention (week 3: 221.87 ± 8.01; week 9: 218.22 ± 11.19), and remained elevated post-intervention (week 12: 216.35 ± 7.5). Post-intervention MET-hrs had decreased from week 3, but were not significantly different from week 9 MET-hrs. There was 85% compliance for all training sessions for both groups. CONCLUSION: Post Bariatric surgery patients increased METs from vigorous intensity exercise intervention similar to obese individuals in moderate continuous exercise training. Although METs for week 12 declined for both groups, it remained above baseline and appears there was no evidence of CSA for either group. Supported by Sentara RMH Hospital and CHBS

Haemodynamic parameters in postmenopausal women - beneficial effect of moderate continuous exercise training.

Physical effort plays a positive role in reducing the risk of cardiovascular diseases. The aim of this study was to assess the cardiovascular status in postmenopausal women after several years of regular amateur training. A total of 55 generally healthy females aged 50-70 years, of whom 38 were members of a senior exercise group and 17 comprised a control group, were enrolled in the study. Parameters of blood flow, vascular resistance, myocardial contractility and thoracic fluid content were measured in a 10-minute supine resting test by impedance cardiography. Thereafter, central blood pressure, augmentation index and pulse wave velocity were measured by applanation tonometry. Exercising women have a better outcome than the control group, when evaluated both with impedance cardiography and with applanation tonometry. They have a lower heart rate - HR (65.1 vs 71.5; p = 0.033), higher blood flow (stroke index - SI, 58.6 vs 50.3; p = 0.040), better myocardial contractility (acceleration index - ACI, 108.8 vs 88.1; p = 0.027), higher preload (thoracic fluid content index - TFCI, 20.5 vs 18.1; p = 0.002), lower afterload (systemic vascular resistance index - SVRI, 1972.9 vs 2110.5; p = 0.026), lower central systolic blood pressure - cBPsys (119.0 vs 129.5; p = 0.037), lower augmentation pressure - AP (10.3 vs 15.0; p = 0.044) and lower pulse wave velocity - PWV (7.4 vs 8.4; p = 0.001). Regular moderate continuous aerobic exercise training has a beneficial impact on the cardiovascular system in postmenopausal women.

Exercise training in patients with chronic heart failure: A new challenge for Cardiac Rehabilitation Community.

Exercise training (ET) is strongly recommended in patients with chronic stable heart failure (HF). Moderate-intensity aerobic continuous ET is the best established training modality in HF patients. In the last decade, however, high-intensity interval exercise training (HIIT) has aroused considerable interest in cardiac rehabilitation community. In HF patients, HIIT exerts larger improvements in exercise capacity compared to moderate-continuous ET. Since better functional capacity translates into symptoms relief and improvement in quality of life in patients with HF, this training modality is collecting growing interest and consensus, not revealing major safety issues. HIIT should not replace other training modalities in HF but should rather complement them. Inspiratory muscle training, another promising training modality in patients with HF, exerts beneficial effect on inspiratory muscle strength and inspiratory endurance, on exercise capacity and quality of life. In conclusion, taking into consideration the complecity of HF syndrome, combining and tailoring different ET modalities according to each patient's baseline clinical characteristics (i.e. exercise capacity, comorbidity, frailty status, personal needs, preferences and goals) seem the most wily approach for exercise prescription.

Exercise training in adults with repaired tetralogy of Fallot: A randomized controlled pilot study of continuous versus interval training

IntroductionAdults with repaired tetralogy of Fallot (ToF) have impaired exercise capacity, vascular and cardiac autonomic function, and quality of life (QoL). Specific effects of high-intensity interval or moderate continuous exercise training on these parameters in adults with repaired ToF remain unknown. Methods and resultsThirty adults with repaired ToF were randomized to either high-intensity interval, moderate intensity continuous training (36 sessions, 2–3 times a week) or usual care (no supervised exercise). Exercise capacity, flow-mediated vasodilation, pulse wave velocity, NT-proBNP and fibrinogen levels, heart rate variability and recovery, and QoL (SF-36 questionnaire) were determined at baseline and after the intervention period. Twenty-seven patients (mean age 39±9years, 63% females, 9 from each group) completed this pilot study. Both training groups improved in at least some parameters of cardiovascular health compared to no exercise. Interval–but not continuous–training improved VO2peak (21.2 to 22.9ml/kg/min, p=0.004), flow-mediated vasodilation (8.4 to 12.9%, p=0.019), pulse wave velocity (5.4 to 4.8m/s, p=0.028), NT-proBNP (202 to 190ng/L, p=0.032) and fibrinogen levels (2.67 to 2.46g/L, p=0.018). Conversely, continuous–but not interval–training improved heart rate variability (low-frequency domain, 0.32 to 0.22, p=0.039), heart rate recovery after 2min post-exercise (40 to 47 beats, p=0.023) and mental domain of SF-36 (87 to 95, p=0.028). ConclusionBoth interval and continuous exercise training modalities were safe. Interval training seems more efficacious in improving exercise capacity, vascular function, NT-proBNP and fibrinogen levels, while continuous training seems more efficacious in improving cardiac autonomic function and QoL. (Clinicaltrials.gov, NCT02643810).

Superior Effects of High-Intensity Interval Training vs. Moderate Continuous Training on Arterial Stiffness in Episodic Migraine: A Randomized Controlled Trial.

Background: Migraine is associated with increased cardiovascular risk and vascular dysfunction. Since aerobic exercise can reduce cardiovascular risk, the present randomized controlled trail aimed at investigating the effects of high-intensity interval training (HIT) vs. moderate continuous exercise training (MCT) on arterial stiffness in migraine patients.Methods: Forty-eight episodic migraineurs were initially enrolled in the study. 37 patients [female: 30; age: 37 (SD: 10); BMI: 23.1 (5.2); Migraine days per month: 3.7 (2.5)] completed the intervention. Central blood pressure, pulse wave reflection, and aortic pulse wave velocity (PWV) were obtained by an oscillometric monitor. Incremental treadmill exercise testing yielded maximal and submaximal fitness parameters. Participants were randomly assigned to either HIT, MCT, or a control group (CON). The intervention groups trained twice a week over a 12-week intervention period.Results: After adjustment for between-group baseline differences, a moderate meaningful overall reduction of the augmentation index at 75 min−1 heart rate (AIx@75) was observed [partial eta squared () = 0.16; p = 0.06]. With 91% likely beneficial effects, HIT was more effective in reducing AIx@75 than MCT [HIT: pre 22.0 (9.7), post 14.9 (13.0), standardized mean difference (SMD) = 0.62; MCT: pre 16.6 (8.5), post 21.3 (10.4), SMD −0.49]. HIT induced a relevant reduction in central systolic blood pressure [cSBP: pre 118 (23) mmHg, post 110 (16) mmHg, SMD = 0.42] with a 59% possibly beneficial effect compared to CON, while MCT showed larger effects in lowering central diastolic blood pressure [pre 78 (7) mmHg, post 74 (7) mmHg, SMD = 0.61], presenting 60% possibly beneficial effects compared to CON. Central aortic PWV showed no changes in any of the three groups. Migraine days were reduced more successfully by HIT than MCT (HIT: SMD = 1.05; MCT: SMD = 0.43).Conclusion: HIT but not MCT reduces AIx@75 as a measure of pulse wave reflection and indirect marker of systemic arterial stiffness. Both exercise modalities beneficially affect central blood pressure. HIT proved to be an effective complementary treatment option to reduce vascular dysfunction and blood pressure in migraineurs.

Exercise training modalities in chronic heart failure: does high intensity aerobic interval training make the difference?

Exercise training (ET) is strongly recommended in patients with chronic heart failure (CHF). Moderate-intensity aerobic continuous ET is the best established training modality in CHF patients. In the last decade, however, high-intensity interval exercise training (HIIT) has aroused considerable interest in cardiac rehabilitation community. Basically, HIIT consists of repeated bouts of high-intensity exercise alternated with recovery periods. In CHF patients, HIIT exerts larger improvements in exercise capacity compared to moderate-continuous ET. These results are intriguing, mostly considering that better functional capacity translates into an improvement of symptoms and quality of life. Notably, HIIT did not reveal major safety issues; although CHF patients should be clinically stable, have had recent exposure to at least regular moderate-intensity exercise, and appropriate supervision and monitoring during and after the exercise session are mandatory. The impact of HIIT on cardiac dimensions and function and on endothelial function remains uncertain. HIIT should not replace other training modalities in heart failure but should rather complement them. Combining and tailoring different ET modalities according to each patient's baseline clinical characteristics (i.e. exercise capacity, personal needs, preferences and goals) seem the most astute approach to exercise prescription.

Pre‐habilitation (i): aggregation of marginal gains

Pre‐habilitation (i): aggregation of marginal gains

Aerobic interval training in patients with heart failure and an implantable cardioverter defibrillator: a controlled study evaluating feasibility and effect

Aerobic interval training (AIT) has been shown to be superior to moderate continuous exercise training in improving exercise capacity and endothelial function in patients with both coronary artery disease and heart failure (HF). The objective of this study was to evaluate this training modality in patients with HF and an implantable cardioverter defibrillator (ICD) with regard to feasibility, safety, and effect. We prospectively included 38 patients with an ICD: 26 patients participated in an AIT programme for 3 months, while 12 patients served as controls. At baseline and 12-week follow up, patients were assessed with a maximal ergospirometry stress test, echocardiography, endothelial function testing, and ICD interrogation. No exercise-related adverse events occurred during or soon after the training sessions. ICD interrogation revealed no sustained arrhythmias, antitachycardia pacing, or ICD discharge related to exercise sessions. The AIT programme led to a significant increase in peak oxygen uptake, cycle ergometer workload, and endothelial function compared to the control group. The training programme was safe and not associated with any adverse events or ICD-related complications. An AIT programme is feasible and seems safe in a well-treated, stable ICD population. Further, AIT for 3 months results in significantly increased aerobic capacity and endothelial function in this population.

Interval and Continuous Exercise Regimens Suppress Hypoxia‐induced Thrombin Generation by Decreased Release of Procoagulant‐rich Microparticles from Neutrophils

The release of procoagulant-rich microparticles from neutrophils accelerates the pathogenesis of inflammatory thrombosis. This study explicates the manner in which interval and continuous exercise regimens affect neutrophil-derived microparticles (NDMP) release and NDMP-mediated thrombin generation (TG). Twenty sedentary males were randomly divided into moderate continuous exercise training group (MCT; 60% VO2max, n=10) and aerobic interval exercise training group (AIT; 3-minute intervals at 80% and 40% of VO2max, n=10) for 30 minutes per day, 5 days per week for 5 weeks. The NDMP characteristics and dynamic TG parameters were measured by two-color flow cytometry and calibrated, automatic thrombinography, respectively. Acute 12%O2 exercise increased release of micrparticles from neutrophils and up-regulated expression of phosphatidylserine (PS) on NDMP, which responses were accompanied by elevated thrombin peak height and increased TG rate in NDMP-rich plasma. However, both MCT and AIT for 5 weeks decreased levels of tissue factor-rich and PS-exposed microparticles released from neutrophils and depressed NDMP-mediated dynamic TG in plasma at rest and following the 12%O2 exercise. Therefore, we conclude that both MCT and AIT ameliorates NDMP-induced TG by down-regulated expressions of pro-coagulant factors on NDMP at performing 12%O2 exercise, which may, in turn, decrease the risk of inflammatory thrombosis evoked by hypoxic stress.

Effects of Interval and Continuous Exercise Regimens on CD4 lymphocyte Apoptotic and Autophagic Responses to Hypoxic Stress

This study investigates how interval and continuous exercise regimens affect CD4 lymphocyte apoptotic and autophagic responses to hypoxic stress. Twenty sedentary males were randomly divided into moderate continuous exercise training group (MCT; 60% VO2max, n=10) and aerobic interval exercise training group (AIT; 3-minute intervals at 80% and 40% of VO2max, n=10) for 30 minutes per day, 5 days per week for 5 weeks. The results demonstrated that acute 12%O2 exercise enhanced apoptosis (phosphotidyl serine exposure) by promoting phosphorylation of Bcl-2 and activations of caspase-9 and -3, as well as, suppressed autophagy (acridin orange staining) by down-regulating expressions of m-TOR, Atg-1, Atg-12, and LAMP-2 in CD4 lymphocytes. However, 5 weeks of MCT and AIT decreased levels of phosphorylated Bcl-2 and active-form caspase-9 and -3 in CD4 lymphocytes, consequently suppressing the cell apoptosis induced by the 12%O2 exercise. Simultaneously, the two regimens promoted autophagy of CD4 lymphocytes at rest or following the 12%O2 exercise, which responses were accompanied by increased cellular Beclin, Atg-1, Atg-12, LC3B, or LAMP-2 level. Therefore, we conclude that both MCT and AIT regimens alleviate apoptosis and promote autophagy of CD4 lymphocytes during hypoxic exercise, which may, in turn, reduce the risk of immune suppression evoked by hypoxic stress.

Aerobic Interval Exercise Training Improves Ventilatory Efficiency in Patients with Chronic Heart Failure

Ventilation-perfusion mismatching is responsible for dyspnea-related exercise intolerance in HF. However, which exercise prescription yields optimal ventilatory efficiency against exercise dyspnea in HF patients remains unclear. This study investigates how interval and continuous exercise regimens affect ventilatory efficiency with exercise in patients with HF. Thirty patients with HF were randomly divided into moderate continuous exercise training group (MCT; 60% VO2peak, n=10), aerobic interval exercise training group (AIT; 3-minute intervals at 80% and 40% of VO2peak, n=10), and general healthcare group (GHC, n=10) for 12 weeks. Hemodynamic and ventilatory responses to exercise were determined by an integrated system of bio-reactance-based measurement and automatic gas analysis. The results demonstrated that AIT increased value of VO2peak, steeped oxygen uptake efficiency slopes (OUES), and depressed VE-VO2 slope, whereas these levels of VO2peak, OUES, and VE-VO2 slope unchanged following MCT. Moreover, AIT furthered the extent of cardiac output (CO) elevated by exercise compared to MCT did. However, GHC decreased hemodynamic and ventilatory responses to exercise below to pre-interventional levels. The COpeak were directly related the OUES and VO2peak, and inversely related to the VE-VCO2 slope. Therefore, we conclude that AIT improves more efficiency in ventilation-perfusion matching during exercise than MCT does in patients with HF.

Different Effects of Interval and Continuous Exercise Regimens on Cerebral and Muscular Hemodynamics in Patients with Chronic Heart Failure

Abnormal cerebral/muscular hemodynamic responses to exercise contribute to the impairment of functional capacity in patients with heart failure (HF). However, which exercise prescription yields optimal peripheral hemodynamic function to improve exercise tolerance in HF patients remains unclear. This study investigates how interval and continuous exercise regimens affect cerebral/muscular hemodynamic responses to exercise in patients with HF. Thirty patients with HF were randomly divided into moderate continuous exercise training group (MCT; 60% VO2peak, n=10), aerobic interval exercise training group (AIT; 3-minute intervals at 80% and 40% of VO2peak, n=10), and general healthcare group (GHC, n=10) for 12 weeks. A near-infrared spectroscopy was employed to assess perfusion/oxygenation in vastus lateralis (VL) muscle and frontal cerebral lobe (FC). Our results demonstrated that the AIT group had a larger improvement in aerobic capacity compared to the MCT and GHC groups. Simultaneously, 12-week AIT enhanced perfusion (Δtotal Hb) and O2 extraction (ΔHHb) of VL during exercise, whereas VL hemodynamic response to exercise remained unchanged following either MCT or GHC intervention. However, none of the 12-week interventions influenced the cerebral perfusion/oxygenation during exercise. Therefore, we conclude that AIT for 12 weeks improves cardiopulmonary fitness, concurrence with enhancing O2 delivery/utilization in skeletal muscles but not cerebral tissues.

Controlled study of myocardial recovery after interval training in heart failure: SMARTEX-HF – rationale and design

The large randomized controlled multicentre clinical trial, HF-ACTION, recently demonstrated that a programme of recommendation of regular exercise training at moderate intensity is safe, improves quality of life, and reduces the combined endpoint of all-cause death and hospitalization in patients with chronic heart failure. However, the size of beneficial effects was modest compared to results published in smaller single studies and meta-analyses. Based on results of a pilot study, the objective of the present investigation is to test the hypothesis that a programme comprising interval training at high relative intensity would yield significantly larger effects in terms of left ventricular remodelling compared to moderate continuous exercise training. In a three-armed randomized multicentre study of stable heart failure patients with left ventricular ejection fraction ≤35%, the effects of a 12-week programme of high-intensity interval training (HIT; 85-90% of peak oxygen uptake, VO(2peak)) will be compared to actual practice in Europe, represented by either an isocaloric programme of moderate continuous training (MCT; 50-60% of VO(2peak)) and a recommendation of regular exercise (RE) of the individual patients' own preference based on clinical practice at the local centre. The primary endpoint is reverse remodelling, defined as change in left ventricular end-diastolic diameter assessed by echocardiography. Secondary endpoints include peak oxygen uptake (VO(2peak)), biomarkers, quality of life, and level of physical activity assessed by questionnaires. In addition, long-term maintenance of effects after the supervised training period will be determined. Assessments will be made at baseline, after the 12-week intervention programme, and at 1-year follow up. A total number of 200 patients on treatment per protocol, randomized to the three groups in a 1 : 1 : 1 manner, is estimated to detect clinically relevant differences in effect with HIT vs. MCT and RE (p < 0.05; statistical power 0.90) for the primary endpoint. Inclusion of patients started May 2009 and will run until total number has been reached.

High-intensity interval training may reduce in-stent restenosis following percutaneous coronary intervention with stent implantation: A randomized controlled trial evaluating the relationship to endothelial function and inflammation

High-intensity interval training has been shown to be superior to moderate continuous exercise training in improving exercise capacity and endothelial function in patients with coronary artery disease. The objective of this study was to evaluate this training model on in-stent restenosis following percutaneous coronary intervention for stable or unstable angina. We prospectively randomized 40 patients after percutaneous coronary intervention with implantation of a bare metal stent (n = 30) or drug eluting stent (n = 32) to a 6-month supervised high-intensity interval exercise training program (n = 20) or to a control group (n = 20). At six months, restenosis, measured as in-segment late luminal loss of the stented coronary area, was smaller in the training group 0.10 (0.52) mm compared to the control group 0.39 (0.38) mm (P = .01). Reduction of late luminal loss in the training group was consistent with both stent types. Peak oxygen uptake increased in the training and control group by 16.8% and 7.8%, respectively (P < .01). Flow-mediated dilation improved 5.2% (7.6) in the training group and decreased -0.1% (8.1) in the control group (P = .01). Levels of high-sensitivity C-reactive protein decreased by -0.4 (1.1) mg/L in the training group and increased by 0.1 (1.2) mg/L in the control group (P = .03 for trend). Regular high-intensity interval exercise training was associated with a significant reduction in late luminal loss in the stented coronary segment. This effect was associated with increased aerobic capacity, improved endothelium function, and attenuated inflammation.

Exercise training in heart failure: reduction in angiotensin II, sympathetic nerve activity, and baroreflex control

neurohumoral excitation has been considered the hallmark of heart failure. At the humoral level, cardiac dysfunction has been shown to be associated with increased angiotensin II, aldosterone, and vasopressin levels. The clinical implication for such humoral dysregulation is the increase in salt and