Introduction: Dyspnea and fatigue determine exercise intolerance in heart failure (HF) subjects, hampering performance in activities of daily living. In this context, noninvasive ventilation (NIV) has been used to minimize such impairment, increasing functional capacity Aim: To evaluate the impact of NIV on exercise performance in HF individuals. Methods: A randomized crossover clinical trial with allocation concealment consisted of two experimental phases: NIV and control, 7 days apart of each other. During NIV phase, 30 minutes of bi-level ventilation was performed. Any type of ventilator support was offered during control phase. Functional capacity was assessed by cardiopulmonary exercise test on a treadmill.

Inclusion Criteria:

• Both sexes, 18-60 years
• body mass index (BMI) <30 kg/m2
• functional class II-III according to the New York Heart Association
• of the echocardiogram últiimos 6 months showing ejection fraction (LVEF) ≤ 45% - echocardiogram of six months showing cardiac hypertrophy (left Ventricular Diastolic Diameter (LVDD)> 55mm
• Diameter Systolic left Ventricular (LVSD)> 45mm )
• optimized from the point of view of drug and (6) clinical stability

Exclusion Criteria:

• (1) unstable angina, myocardial infarction or heart surgery three months before the beginning of the research

  (2) chronic orthopedic, infectious or metabolic diseases

  (3) FEV1/FVC <70% predicted characterizing obstructive respiratory disorder; (4) active smokers

  (5) Limitation on the use of NIV: claustrophobia, inability to remain with their mouths closed, abdominal distention, hemodynamic instability, heart rate (HR) <60 bpm, recent trauma, nausea and vomiting face