Cognition and Exercise Training

The aim of study is to investigate the impact of two different training modalities (high intensity interval training (HIIT) versus moderate intensity continuous exercise training (MICET) on cognitive performance, cerebral oxygenation, cardiac output and physical fitness in older healthy adults, patients with metabolic syndrome, coronary heart disease and heart failure. The investigators hypothesized that HIIT modality will lead to a larger improvement in physical fitness (i.e. VO2peak), cardiovascular parameters (cardiac output and stroke volume) and cognitive performance at rest and during submaximal exercise. The primary endpoint will be the improvement in cognitive performance.


Eligibility Criteria:
Inclusion criteria:

Elderly healthy subjects : with no MetS and no-documented CHD, both males and females, aged\>60 years will be included in the study, should they provide written informed consent and have a sufficient initial physical and intellectual capacities allowing an independent daily living.

Patients with metabolic syndrome and no-documented CHD, both males and females, aged \> 18 years will be included in the study, should they provide written informed consent and have a sufficient initial physical and intellectual capacities allowing an independent daily living. MetS will be defined according to recent updated criteria: presence of at least three of five criteria, namely abdominal obesity (waist circumference cut-off depending on the recently published ethnic-based variations, triglycerides \> 1.70 mmol/l, decreased HDL-cholesterol (\< 1.0 mmol/l in men and \< 1.3 mmol/l in women), systolic blood pressure \> 130 mmHg or diastolic blood pressure \> 85 mmHg, and FPG \> 5.6 mmol/l.

CHD patients, both males and females, aged \> 18 years will be included in the study, should they provide written informed consent and have a sufficient initial physical and intellectual capacities allowing an independent daily living. Moreover, they must have documented CHD (prior myocardial infarction, prior coronary angiography or angioplasty, or documented myocardial ischemia on myocardial scintigraphy).

Patients with documented stable chronic heart failure will be recruited if they show the following inclusion criteria:

* ≥18 years
* Left ventricular ejection fraction (LVEF) \<40% (measured within 6 months of their enrolment by MUGA Scan, echo or radiological ventriculography)
* NYHA functional class I-III
* Optimal therapy at stable doses including a beta-blocker and an ACE inhibitor or ARA for at least 6 weeks prior to investigation (unless documented rationale for variation).
* Able to perform an symptom limited exercise test.
* Capacity and willingness to sign the informed consent form.

Exclusion Criteria:

* For healthy elderly subjects:
* age under 60 years
* lack of expressed written consent
* metabolic syndrome
* coronary heart disease
* chronic systolic heart failure
* resting left ventricular ejection fraction \< 40 %
* symptomatic aortic stenosis
* chronic atrial fibrillation
* malignant exertional arrhythmias
* non-cardiopulmonary limitation to exercise (e.g: arthritis or claudication)
* severe exercise intolerance.

For patients with metabolic syndrome:

* lack of expressed written consent
* coronary heart disease
* chronic systolic heart failure
* resting left ventricular ejection fraction \< 40 %
* symptomatic aortic stenosis
* chronic atrial fibrillation
* malignant exertional arrhythmias
* non-cardiopulmonary limitation to exercise (e.g: arthritis or claudication)
* severe exercise intolerance.

For patients with CHD

* lack of expressed written consent
* recent acute coronary event (\< 3 months)
* chronic systolic heart failure
* resting left ventricular ejection fraction \< 40 %
* symptomatic aortic stenosis
* severe non-revascularize coronary disease including left main coronary stenosis
* patient awaiting coronary artery bypass surgery
* chronic atrial fibrillation
* presence of permanent ventricular pacemaker
* malignant exertional arrhythmias
* non-cardiopulmonary limitation to exercise (e.g: arthritis or claudication)
* severe exercise intolerance.

For CHF patients:

* Any relative or absolute contraindications to exercise training among patients with stable chronic heart failure according to current recommendations (Working Group on Cardiac Rehabilitation 2001)
* Fixed-rate pacemaker or ICD devices with heart rate limits set lower than the exercise training target heart rate.
* Major cardiovascular event of procedure within the 3 months preceding enrolment in the study.
* Atrial fibrillation
* Heart failure secondary to significant uncorrected primary valvular disease (except for mitral regurgitation secondary to LV dysfunction)
* Heart failure secondary to congenital heart disease or obstructive cardiomyopathy.