Doctors may use exercise testing to evaluate people with a possible lung disorder. These tests are different from exercise stress tests done to diagnose heart disorders. The 2 most common forms of exercise testing are:
Six-minute walk test
Full cardiopulmonary exercise testing
(See also Medical History and Physical Examination for Lung Disorders.)
Six-minute walk test
This simple test measures the maximal distance that people can walk at their own pace in 6 minutes on a flat surface. In addition to the distance walked, the blood oxygen level and heart rate are monitored and recorded throughout the test using pulse oximetry. The test assesses the person's overall function but, if the person's exercise capacity is reduced, does not tell which of the individual organs and systems (that is, the heart, lungs, muscles and bones, or other organs and systems) is the limiting factor. The test results can be affected by the person's effort.
This test is used , to monitor response to treatments and pulmonary rehabilitation, before lung transplantation and lung volume reduction surgery, and to predict the risk of disability or death in people with heart and lung disorders.
Cardiopulmonary exercise testing
This computerized test analyzes heart and lung function and provides information, such as how much air flows through the lungs, how much carbon dioxide is being produced, and how well the lungs are getting oxygen into the blood and removing carbon dioxide from it. The test starts while the person is at rest and continues as the person exercises on a treadmill or stationary bicycle (cycle ergometer); the person wears several different types of measurement devices, usually including a mask to measure breathing, oxygen and carbon dioxide, a blood pressure monitor, a pulse oximeter, and an electrocardiographic monitor. The intensity of the exercise is increased gradually until symptoms prevent further exercise. Depending on the person's physical capability and why the test is being done, they person may or may not reach maximal exercise.
Cardiopulmonary exercise testing primarily determines whether a person's capacity to exercise is normal or reduced and if it is reduced, whether the reduction is because of heart and/or lung problems or deconditioning. The test can detect problems at an earlier stage than would tests that are less comprehensive or done only at rest.
Doctors can also use cardiopulmonary exercise testing to monitor a person's response to treatment and guide exercise in pulmonary rehabilitation programs.
