Exercise Tolerance Test (ETT)


An Exercise Tolerance Test, also known as Exercise Stress Test is used to measure the effect of exercise on your heart. The technician will place 10 flat, sticky patches called electrodes on your chest. These are attached to an ECG monitor that follows the electrical activity of your heart during the test. You will walk on a treadmill or pedal on an exercise bicycle. About every 3 minutes you will be asked to walk (or pedal) faster. You will also have to walk on a steeper angle or pedal with more resistance in on a bike. This is like walking fast or jogging up a hill.

While you exercise, the activity of your heart is measured with an electrocardiogram (ECG). Your blood pressure readings are also taken. Electrodes (conductive patches) will be placed on your chest to record the heart's activity. You may feel mild burning or stinging when the electrode sites are prepared. You will have a blood pressure cuff on your arm that will be inflated every few minutes. This will produce a tight, squeezing feeling.

The test continues until:
  • You reach a target heart rate.
  • You develop chest pain or a change in your blood pressure that is concerning.
  • ECG changes show that your heart muscle is not getting enough oxygen.
  • Your heart rhythm changes.
  • You are too tired or have other symptoms, such as leg pain.


You will be monitored for 10 to 15 minutes after exercising, or until your heart rate returns to baseline.

Reasons for this test:
  • Chest pain.  The test is done to check for narrowing of the arteries.
  • Angina is becoming more severe or is happening more often.
  • Had a heart attack.
  • Had angioplasty or heart bypass surgery.
  • Going to start an exercise program and you have risk factors.
  • Want to look for heart rhythm changes that may occur during exercise
  • You need further testing for heart valve problem.