Introduction

Before exercise tolerance is evaluated, the practitioner must carefully consider a number of factors that will ultimately influence the interpretation of results and ensuing interventions. These include purpose of the test (Chapter 1), key variables required for accurate test interpretation (Chapter 4), and the best test available for the test objectives (Chapter 3). In considering which data will best serve these objectives, the practitioner should select the most appropriate instrumentation available their collection. This chapter presents a number instrumentation options in the context of test purposes and data desired for interpretation. These include relatively simple field tests, submaximal laboratory tests, and maximal effort tests. Details actual application of these instruments will be presented in Chapter 3. Each instrument will be presented with its description and principle of operation followed by methods of calibration, its accuracy, and precision. Maintenance of the instrument is also discussed. This chapter begins with a brief review of important measurement concepts that influence instrument selection. Figure 2.1 illustrates these concepts.

Measurement concepts

Validation

An instrument is thought to be valid if it accurately measures the variable(s) it is said to measure. For example, a heart rate meter is valid if it accurately represents the true value of the heart rate. It is prudent for the practitioner to ensure the accuracy of measurement instruments. This requires periodic validation studies in which the instrument in question is compared against a “gold standard” or reference method in its ability to measure the variable in question.