An aerobic physical exercise protocol will be applied to patients admitted in ward due to decompensated heart failure, in order to validate the efficacy and safety of physical exercise in this phase of clinical stabilization, through the said training protocol - ERIC program.

With the objective of validating the efficacy and safety of physical exercise as a therapeutic resource in patients admitted for decompensated heart failure; will be applied, by rehabilitation nurses, a protocol of physical exercise, with increasing levels of intensity. Patients who meet the inclusion criteria will be randomized through an online program (randomizer.org) and the ERIC protocol will be applied to the test group. The control group will be implemented the usual care of rehabilitation nursing. The ERIC protocol comprises 5 levels of intensity, as following shown: Stage 1 - respiratory and calisthenic exercises (5-10 minutes) Stage 2 - pedal for 5-10 minutes Stage 3 - aerobic training: walking on the corridor for 5-10 minutes Stage 4 - aerobic training: walking on the corridor for 10-15 minutes Stage 5 - aerobic training: walking on the corridor for 15 minutes + climbing stairs for 5 minutes All patients will be monitored and followed up by a rehabilitation nurse while they are doing the exercise. The investigator decides, depending on the patient's performance and clinical conditions, the form of progression in the program, but it is mandatory to follow the previously defined levels of intensity.

Patients in the test group may start the program only on stage I or II according to clinical criteria. At admission of the patients (test group and control group) clinical and sociodemographic parameters are evaluated, as well as data related to Barthel's indices and London Chest of activities of daily living (LCADL). At the discharge date, the Barthel index and the LCADL scale will also be evaluated, as well as the 6-minute walking test.

Inclusion Criteria:

• Admission diagnosis of Decompensated heart failure
• More than 18 years old
• Capacity to provide informed consent

Exclusion Criteria:

• Osteoarticular pathology that impedes the performance of the exercise
• Existence of inotropic infusions
• Dysrhythmia or precordial pain in the last 24 hours
• Acute pulmonary edema in the last 12 hours
• Systolic blood pressure greater than 180millimetre of mercury (mmHg) or less than 80mmHg (except in cases where this is the baseline value for the patient)
• Need for oxygen at a rate greater than 3 /min
• Glycemic decompensation in the last 12 hours