The use of exercise testing has expanded greatly to help guide decisions regarding medical management and prognosis in a broad spectrum of patients. Numerous epidemiologic studies in people with and without documented coronary artery disease have identified a low level of cardiorespiratory fitness as an independent risk factor for all-cause and cardiovascular mortality. Moreover, recent data support the hypothesis that exercise capacity is inversely associated with health care costs. Accordingly, unfit men and women should be counseled to exercise in home-based or group preventative or rehabilitative programs. One of the most important challenges in providing quality programs is hiring personnel with the competencies and knowledge to conduct diagnostic and/or functional testing and safe and effective exercise interventions. The latter may include structured exercise regimens, increased lifestyle physical activity, or both. In the era of managed care, the use of specialized exercise professionals for the supervision of exercise testing and training may represent a safe and cost-effective alternative to many hospitals, clinics, and private physician practices. Clinical exercise physiologists (CEPs) – professionals who utilize exercise testing and/or training in the evaluation and management of a broad spectrum of healthy persons and patients – can play a critical role in favorably modifying clients’ level of cardiorespiratory fitness and physical activity habits. In this discussion paper, we detail the training of CEPs, and outline the clinical settings where they have contributed substantially to health care delivery. We also outline the role of Registered Clinical Exercise Physiologists (RCEPs) – clinical exercise physiologists with advanced training (e.g., MSc) often involved in cardiovascular rehabilitation.