What is an exercise tolerance test?
An electrocardiogram (ECG) that is taken whilst you are walking on a treadmill. The test is designed to detect any changes in your heart function between when you are resting and exercising.
Why do I need to have this test?
Your doctor has requested that you have this simple test to see how well your heart works when you are active.
How should I prepare for my test?
We advise you to wear comfortable clothing and footwear for the test.
Please do not wear a full-length slip or dress.
You are also advised not to eat a heavy meal or smoke before the test.
What happens during the test?
The Physiologist will ask you to undress to the waist (you can use a gown if required), and you will be fitted with 10 ECG electrodes. An ECG and blood pressure reading will then be taken. You will be asked to walk on the treadmill while the Physiologist records a further series of ECGs and blood pressure readings.
You may have chest discomfort symptoms before, and this test might cause similar feelings. If you notice any of your symptoms during the test, please tell the Physiologist right away.
Are there any risks involved with this test?
The risk of death or serious complications such as heart attack during this test is approximately 1 in 10,000 (0.01%). The risk of a serious heart rhythm problem during this test is about 1 in 5000 (0.02%). We follow all necessary procedures and precautions to keep you safe.
After the test
When/how will I receive the results of the test?
The results will be passed onto the doctor who requested the test. You are usually told the results at your next clinic appointment or a letter may be sent to your GP.
What will happen if I do not want to have this test?
If you do not have this test we will not be able to pass important diagnostic information to the doctors. This may affect the medical treatment that you receive.
If you or the individual you are caring for need support reading this please ask a member of staff for advice.
© North Bristol NHS Trust. This edition published February 2026. Review due February 2029. NBT002908.