A patient is considered stressed upon reaching 85 percent of maximum heart rate, which is calculated by subtracting the patient's age from 220 for men and 210 for women, according to Patient.co.uk. However, a 2011 study suggests use of the metric underestimates inducible ischemia.
Stress tests are performed at a medical facility, where 10 sticky electrodes are placed on the patient's chest. The electrodes are linked to a monitor that displays the electrical activity of the patient's heart during the test. The patient walks on a treadmill or cycles on a stationary bike, with the speed increasing in three-minute intervals until the target heart rate is reached, according to MedlinePlus.