Aerobic Exercise in Patients With Pulmonary Hypertension

This study will determine if a rehabilitation exercise program can help people with pulmonary hypertension (PH) increase their physical activity. Patients with PH have an increase in blood pressure in the pulmonary blood vessels (artery, vein or capillaries) that leads to shortness of breath, dizziness, fainting and other symptoms. Healthy volunteers and people with pulmonary hypertension between 21 and 75 years of age may be eligible for this study. All participants undergo the following tests and procedures: * Medical history and physical examination * 6-minute walk test: Subjects walk as fast as they can for 6 minutes on a walking track to determine their ability to participate in physical activity. * Questionnaires: Subjects complete nine questionnaires related to their fatigue, daily physical activity, mood, and so forth. * Maximum treadmill test: The exercise begins at an easy level and gradually increases until the subject says he or she can no longer continue or the investigator decides it is not safe to continue. Subjects are fitted with a mask, electrodes and light sensors to measure how well the heart is working and how well the muscles use oxygen. Patients with pulmonary hypertension undergo the following additional procedures: * Activity monitoring: Patients wear a monitor for 3 days that measures movement and heart rate. * Group assignment: Patients are randomly assigned to Group 1 (education plus aerobic exercise) or Group 2 (education followed by exercise). * Group 1 patients will attend classes three days a week at either Inova Fairfax Hospital Pulmonary Rehabilitation Center or The National Institutes of Health for 10 weeks. Two sessions a week will include a 1 hour education session as well as a 30-45 minute track or treadmill exercise session. The third session will only include exercise. During the education patients will learn about a healthy lifestyle with pulmonary hypertension. After the 10 weeks of education and exercise, subjects repeat the 6-minute walk test, maximum treadmill test and questionnaires. * Group 2 patients participate in 2; 1-hour educational session at either the Inova Pulmonary Rehabilitation Center or The National Institutes of Health for 10 weeks. After the classes, they repeat the 6-minute walk test, maximum treadmill test and questionnaires. The following 10 weeks will consist of 3 days a week of 30-45 minute track or treadmill walking at either Inova or NIH, after which they again repeat the questionnaires, treadmill and walk tests.

* INCLUSION CRITERIA: PH and ILD-only Groups: Subjects of this study will include individuals with ILD and PH who are referred for Pulmonary Rehabilitation. Patients with ILD, PH or PH comorbid with ILD will be included. The following list provides more specific inclusion criteria: * Between age 21-82 years * WHO functional class II or III, will accept WHO functional class I and IV based on 6 minute walk test results (less than or equal to 400 meters for Class I and greater than or equal to 50 meters for Class IV) * No recent syncope or significant chest pain * No prior Pulmonary Rehabilitation received within the last 6 months. * Physically inactive, no participation in a structured exercise program 3 or more days a week for over 30 minutes at each session including pulmonary rehabilitation maintenance within the last 6 months. * Patients may qualify if they have any one of the following conditions: * PAH diagnosed by right heart catheterization defined as resting pulmonary mean arterial pressure equal to or higher than 25 mmHg * Interstitial lung disease, including idiopathic pulmonary fibrosis (IPF), non-specific pulmonary fibrosis (NSPF), sarcoidosis or other form of chronic lung fibrosis will be based on clinical context via clinic note from primary pulmonologist and an echo within one year of enrollment showing an RVSP \