Exercise Testing: Who, When, and Why?

There are different modalities of exercise testing that can provide valuable information to physicians about patient and athlete fitness and cardiopulmonary status. Cardiopulmonary exercise testing (CPX) is a form of exercise testing that measures ventilatory and gas exchange, heart rate, electrocardiogram, and blood pressures to provide detailed information on the cardiovascular, pulmonary, and muscular systems. This testing allows an accurate quantification of functional capacity/measure of exercise tolerance, diagnosis of cardiopulmonary disease, disease-progression monitoring or response to intervention, and the prescription of exercise and training. CPX directly measures inhaled and exhaled ventilator gases to determine the maximal oxygen uptake, which reflects the body's maximal use of oxygen and defines the limits of the cardiopulmonary system. CPX is the ideal modality to evaluate causes of exertional fatigue and dyspnea, especially in complex cases in which the etiology could be cardiac, pulmonary, or deconditioning. Exercise tolerance has become an important outcome measure in patients with chronic obstructive pulmonary disease and congestive heart failure, as well as other chronic diseases, and is a well-recognized predictor of mortality. Older athletes or those with underlying medical conditions could benefit from exercise testing for risk stratification and clearance to participate, as well as to help set their training zones and determine their functional limitations.