Normal Exercise Physiology
Clinical Indications and Utility of CPET
Equipment, Conduct, and Measurements
Variables Assessed During Exercise
Reproducibility of CPET Results
Provide a brief overview of normal exercise physiology and responses.
Outline the clinical indications, utility, conduct, and interpretation of cardiopulmonary exercise testing.
Highlight characteristic responses commonly demonstrated by patients with various symptoms and disorders frequently assessed by the pulmonologist.
Physical activity in the healthy human involves the active and effective integration of respiratory, cardiovascular, neuromuscular, and metabolic functions. Organs involved in these varied and important roles have sizeable reserve, with the consequence that clinical manifestations of a disease state or abnormality may not become readily apparent until the functional capacity of the organ(s) is markedly impaired. When this occurs, patients commonly experience the distressing, and often disabling, symptoms of shortness of breath with activity and exercise limitation. Cardiopulmonary exercise testing (CPET) allows the clinician to objectively evaluate these important functions and symptoms. Objective assessment and measurement of various parameters during exercise, which strategically places an increased physiologic demand on the functional reserve capacity of these organs, can also provide a sensitive method for the early detection of abnormal function and response(s). Exercise testing results parallel functional capacity and quality of life more closely than measurements obtained only at rest, and accurately predict important outcomes, such as mortality, in a variety of patients and clinical circumstances. While CPET has been previously viewed as being merely interesting (in the hands of a few individuals), it is now cemented into mainstream clinical practice. In view of these meaningful benefits, the conduct and interpretation of CPET is now an essential competency for practicing pulmonologists.