Exercise testing: why, which and how to interpret

Key pointsAn exercise test should be performed: if there is impaired exercise tolerance; to find out which system is limiting exercise; to establish which organ systems have an abnormal response during or after exercise; to investigate how much exercise is appropriate/safe in a patient; and to determine the response to treatment.Prediction of exercise performance based solely on resting pulmonary function tests is inaccurate.The gold standard in exercise testing is the incremental exercise test.Two types of ergometers can be selected for incremental exercise testing: a treadmill or a cycle ergometer. More muscle mass is put to work using a treadmill when compared with cycling.Incremental exercise testing and field testing have complementary value in, for example, pulmonary rehabilitation.Exercise laboratories should be encouraged to test some healthy control subjects in the age span of interest to evaluate which normal values best suit their laboratory setting.Educational aimsTo address some questions that often arise when exercise testing is performed in the clinical routine:What are the indications to perform an exercise test?Which test should be used for which situation?How should the test be carried out in practice?How should the results of the test be interpreted?SummaryExercise testing is widely applied in clinical practice. The aim of this article is to address some questions that often arise when exercise testing is performed in clinical routine. Two complementary tests will be discussed in more detail: the maximal incremental ergometer test and the timed walk test.First, the indication to perform exercise testing is discussed. The second question is which test to apply and how to carry out the test in practice. Finally, the interpretation of the results of the tests are discussed.