Richard J. Simpson, Ph.D., FACSM, is an associate professor in the Departments of Nutritional Sciences, Pediatrics and Immunobiology at the University of Arizona. His research interests are concerned with the effects of aging, stress and exercise on the immune system. Major focus areas include understanding: 1) how exercise and other behavioral interventions can offset age-related decrements in the normal functioning of the immune system (immunosenescence); 2) how adrenergic receptor signaling can be used to improve cellular products for hematopoietic stem cell transplantation and immunotherapy; and 3) the interplay between the immune and neuroendocrine system during high level human performance and extreme isolation (e.g., space travel). Dr. Simpson is a fellow of the American College of Sports Medicine (ACSM) and president-elect of the International Society of Exercise Immunology (ISEI). He sits on the editorial boards of Brain, Behavior and Immunity, Exercise Immunology Review and Immunity and Ageing.