A clinical exercise physiologist works with a variety of patients to maintain or improve their health through physical activity. In this career, your duties may involve working with people with chronic medical conditions such as heart or lung disease, asthma, or diabetes. Your responsibilities may include assessing their needs, monitoring their exercise, and ensuring that they are following safe exercise practices. A certified exercise physiologist, also known as a CEP, may also work with patients who are recovering from a medical emergency or need to regain physical strength following surgery.