All patients were evaluated 24 hours after hospitalization for demographic characteristics (age, gender, occupation, education, and monthly income), smoking history (pack year calculation, smoking status), Charlson index , and body composition. After 48 hours of hospitalization, all patients performed a 6-minute walk test (6MWT) and a new spirometry test, and BODE index was calculated . Finally, after 72 hours of hospitalization patients underwent aerobic exercise on a treadmill for 15 minutes.