Each patient was educated about the benefits of PhA in PAH on the initial visit. Patients wore pedometers (Omron HJ-321-E) for 2 weeks. After PhA assessment, the patients were contacted by a physician. Patients who walked \<5,000 steps per day were recommended to increase PhA, and patients who walked ≥5,000 steps per day were recommended to maintain PhA. Patients wore pedometers for 3 months until their next visit. The primary endpoint was the number of steps after 12 weeks of the study; the secondary endpoint was the 6-minute walk test distance (6MWD), quality of life (SF-36), acceptance of the disease, and anxiety and depression level (HADS).