The purpose of this study is to determine whether high intensity interval training (HIIT) is superior to moderate continuous training in increasing cardiopulmonary capacity in heart failure with preserved ejection fraction patients.

High intensity interval training (HIIT) has been proved to increase oxygen consumption, having superior cardiovascular effect when compared to moderate continuous training (MCT) in post-infarction patients (Wisloff et al.) Aerobic training also had shown positive effect on oxygen consumption and diastolic function in subjects with HFPEF when compared to usual care (Edelmann et al).

However, the comparison of HIIT and MCT on improving functional capacity and diastolic function in HFPEF patients has not yet been study.

Inclusion Criteria:

• Patients with heart failure with preserved ejection fraction (HFPEF) of any etiology that have functional class of the New York Heart Association (NYHA) between I and III, left ventricular ejection fraction > 50% and who meet clinical and echocardiography criteria for HFPEF according to the consensus statement on the diagnosis of heart failure with normal left ventricular ejection fraction by the Heart Failure and Echocardiography Associations of the European Society of Cardiology (Paulus et al.). Patients should be clinical stable for the last 3 months and under optimized pharmacologic treatment, being capable of walking without limitations.

Exclusion Criteria:

• Patients with exercise-induced unstable ventricular arrhythmias, unstable angina, moderate to severe valvular heart disease, severe pulmonary disease, severe anemia, cognitive limitations to understand study protocol, use of pacemaker, autonomic neuropathy, cardiovascular event for less than 3 months, congenital heart disease, terminal illness with less than 1 year of life expectancy, peripheral arterial disease with intermittent claudication or osteoarticular conditions limiting exercise will be excluded.