Question

Give an example of a population of clients for which submaximal testing is a better choice for evaluating cardiorespiratory fitness than is maximal testing.

Answer 1

Compared with maximal exercise testing, submaximal exercise testing appears to have greater applicability to physical therapists in their role as clinical exercise specialists. This review contrasts maximal and submaximal exercise testing. Two major categories of submaximal tests (ie, predictive and performance tests) and their relative merits are described. Predictive tests are submaximal tests that are used to predict maximal aerobic capacity. Performance tests involve measuring the responses to standardized physical activities that are typically encountered in everyday life. To maximize the validity and reliability of data obtained from submaximal tests, physical therapists are cautioned to apply the tests selectively based on their indications; to adhere to methods, including the requisite number of practice sessions; and to use measurements such as heart rate, blood pressure, exertion, and pain to evaluate test performance and to safely monitor patients.Although maximal exercise testing is considered the gold standard for assessing maximal aerobic capacity, the role of such testing is limited in people whose performance may be limited because of pain or fatigue rather than exertion and in cases where maximal exercise testing is contraindicated. Submaximal exercise testing overcomes many of the limitations of maximal exercise testing, and it is the method of choice for the majority of individuals seen by physical therapists in that these individuals are likely to be limited physically by pain and fatigue or have abnormal gait or impaired balance. This article contrasts maximal and submaximal exercise testing and describes the clinical application of submaximal testing. The strengths and limitations of both predictive and performance submaximal tests and the means of maximizing validity and reliability of data are presented. Predictive tests are submaximal tests that are used to predict maximal aerobic capacity. Typically, heart rate (HR) or oxygen consumption (V̇O2) at 2 or more workloads is measured. A predicted V̇O2 value is obtained by extrapolating the relationship between HR and V̇O2 to age predicted maximal heart rate (HRmax). Performance tests involve measuring the responses to standardized physical activities that are typically encountered in everyday life. Finally, we discuss the use of submaximal exercise testing in clinical decision making and the implications for professional education and research.