Previous studies have evaluated the effects of inspiratory muscle training in patiens with heart failure and reduced ejection fraction; nevertheless,no evidence endorse the therapeutic role of inspiratory muscle training in patients with heart failure and preserved ejection fraction. The investigators sought to evaluate whether 12-week inspiratory muscle training improves exercise capacity (peak exercise oxygen uptake and 6-minutes walk test), as well as left ventricular diastolic function, serum biomarkers and quality of life (Minnesota Living With Heart Failure Questionnaire) in patients with heart failure with preserved ejection fraction and non-reduced inspiratory muscle strength.

Inclusion Criteria:

• a) previous history of symptomatic heart failure (New York Heart Association [NYHA] functional class ≥II)
• b) evidence of normal left ventricular ejection fraction, defined by an ejection fraction >0.50 and an end-diastolic diameter <60 mm by 2D echocardiography
• c) relevant structural heart disease (left ventricle hypertrophy/left atrial enlargement) and/or diastolic dysfunction estimated by 2D echocardiography
• d) clinical stability, including no admissions in the past 30 days

Exclusion Criteria:

• a) Patients unable to perform a valid baseline exercise test.
• b) Unstable angina, myocardial infarction or cardiac surgery within the previous three months.
• c)Known chronic metabolic, orthopedic, infectious disease or previous pulmonary disease;
• d)Treatment with steroids, hormones, or cancer chemotherapy;
• e)Reduced maximal inspiratory pressure according to age and sex;
• f)Active smokers
• g)Acute decompensation;
• h)Other comorbidity with an expectancy of life less than one year