Inclusion Criteria:  subjects with proven positivity to the molecular test for Sars-cov2 with demonstration of microbiological healing patients discharged from FPG or other hospital structures; or only contact in PS; or home management age: range 20-60 years Fatigue operationalized as an affirmative answer to item "7" (CES-D)  Exclusion Criteria:  Pharmacological therapies with possible interactions with the mechanisms / processes under study (e.g. antihypertensive drugs, cortisone drugs, NSAIDs, immunosuppressants, nitrates)