This project is concerned with the integration of behavioral principles with physiological measurement for application to clinical medicine. Subjects are normal volunteers recruited from the BLSA and/or the community who are studied to provide normative data on the response of persons with normal hearts and lungs to a breathing challenge using their diaphragm. Comparative groups are patients selected from various medical clinics who are characterized and compared with the normal volunteers. If the performance of those persons with pathophysiology is determined to be less than normal, or volunteers or groups of persons who are high-performers, behavioral techniques can be applied in training subjects to breathe diaphragmatically and improve cardiopulmonary response. If the breathing challenge is an exercise, then the comparison of this test to standard, graded exercise tests could improve the description of cardiopulmonary performance in normal, aged persons and those with pathophysiology.