Pulmonary involvement and fibrosis could be seen in patients after COVID-19. Especially diffusion capacity, pulmonary function, exercise capacity and muscle strength have decreased in patients with COVID-19. Some symptom complaints of patients might continue after the disease, also. It has been shown that COVID-19 causes pulmonary involvement. However, the number of studies revealing the extent of pulmonary and extrapulmonary exposure due to COVID 19 comparing to healthy individuals is very limited, and has not been adequately investigated yet.

Patients who had diagnosed with COVID-19 and participants who do not have any diagnosed disease will be evaluated in this study. Twenty-five patients with post COVID-19 and 25 age- and sex-matched healthy controls will be included according to inclusion and exclusion criteria. All assessments will be completed in two days. Oxygen consumption, physical activity level, chronotropic response, pulmonary function, functional exercise capacity, respiratory and peripheral strength, inspiratory muscle endurance, functional dyspnea, fatigue perception and quality of life will be investigated in patients with COVID-19 and compared with age- and sex-matched healthy controls.

Primary outcome measurements will be oxygen consumption (cardiopulmonary exercise test), chronotropic response (results of cardiopulmonary exercise test) and physical activity level (multi sensor activity device). Secondary outcome will be pulmonary function (spirometer), functional exercise capacity (six minute walk test), respiratory muscle strength (mouth pressure device), peripheral muscle (hand-held dynamometer) strength, inspiratory muscle endurance (incremental threshold loading test), dyspnea (London Chest Daily Living Activity Scale), fatigue (Fatigue Severity Scale) and quality of life (Saint George Respiratory Questionnaire) and functional status (Post-COVID-19 Functional Status Scale).

Inclusion Criteria:

Patients;

• aged between 18-75 years
• diagnosed with COVID-19 before
• patients whose COVID-19 Polymerase Chain Reaction test turned negative or be negative already
• patients who are willing to participate in this study.

Healthy controls;

• aged between 18-75 years
• patients who are willing to participate in this study.

Exclusion Criteria:

Patients;

• body mass index >35 kg/m2
• cancer, renal or hepatic diseases
• aortic stenosis, complex arrhythmia, aortic aneurysm
• serious neurological, neuromuscular, orthopedic, other systemic diseases or. other diseases affecting physical functions
• uncontrolled hypertension and/or diabetes mellitus, heart failure and cardiovascular disease
• acute pulmonary exacerbation, acute upper or lower respiratory tract infection
• cognitive impairment that causes difficulty in understanding and following exercise test instructions
• bulla formation in the lung
• participated in a planned exercise program in the last three months
• contraindication for exercise testing and/or exercise training according to the American College of Sports Medicine

Healthy controls;

• history of coronavirus disease
• history of smoke exposure below 10 packs*years
• have any diagnosed chronic or systemic diseases
• have psychiatric disorder
• body mass index >35 kg/m2
• cognitive impairment that causes difficulty in understanding and following exercise test instructions
• acute pulmonary exacerbation, acute upper or lower respiratory tract infection

At least 25 patients with COVID will be included in patients group and 25 healthy individuals will be included in control group.