Intensive Care Unit's Inclusion Criteria:  All patients diagnosed with COVID-19, mechanically ventilated for at least 24 hours, admitted to the Intensive Care Unit for treatment will be selected for eligibility. Those patients who are not sedated or have an adequate level of awakening (Richmond Agitation Score- Sedation Scale (RASS) > -3 at the time of inclusion in the study within 48 hours after stopping sedation and are able to respond to simple commands will be eligible) and to provide your informed consent.  Intensive Care Unit's Exclusion Criteria:  Exclusion criteria will be: coma (GCS≤ 8); intense agitation, clinical history of neuromuscular or cognitive instability, pregnancy and contraindications for non-invasive cerebral stimulation.  Hospital's Inclusion Criteria  Patients will be considered eligible if: they are hospitalized in a hospital bed for the treatment of COVID-19, using spontaneous breathing or non-invasive ventilation; and are alert and able to participate in training with a score on the Riker scale of 4 points.  Hospital's Exclusion Criteria:  Patients will be excluded if they are experiencing significant distress that interfered with their ability to participate in the study and respond to commands and are considered clinically unstable.