Exercise testing for functional evaluation and exercise prescription.

Although radionuclide tests, despite their high cost, are being used with ever-increasing frequency in diagnostic testing, the ECG exercise stress test remains the best method for providing inexpensive, noninvasive information on how patients will function in vocational and recreational pursuits. This article explains the usefulness of respiratory gas analysis measurements in evaluating performance as well as providing some substitutes when direct measurement is not available. Various exercise test modifications that help in prescribing exercise for athletes, able-bodied cardiac patients, or the disabled are also described.