The cardiopulmonary exercise testing (CPET) is known to be the gold standard method for the assessment of functional capacity. However, the method is expensive, often not well tolerated by the patients, and may not be a good strategy to evaluate activities of daily living (ADL). Functional tests are indirect method to assess functional status or functional capacity of an individual to perform ADL and meet their metabolic demands. These tests are considered objective measures that can monitor the clinical course of several diseases as well as responses to interventional therapies.

Walking and running tests were originally developed to evaluate and estimate aerobic physical fitness of healthy individuals and correlate it with maximal aerobic power (peak VO₂). Balke, in the sixties, followed by Cooper and his 12-minute test, used to evaluate physical performance in healthy subjects, motivated, according to them, by the need of field tests for screening of large populations. These methods showed good correlation with laboratory measurements of aerobic capacity (peak VO₂ and anaerobic threshold).

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