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Cardiopulmonary Exercise Test (CPET)

Patient information A-Z

exercise bike and treadmill with equipment used for performing a cardio pulmonary exercise test

Purpose of test?

A Cardiopulmonary Exercise Test (CPET) is used to assess your exercise capacity and investigate the response of the heart and lungs. The test is useful for identifying causes of shortness of breath, a number of cardiac and respiratory conditions and also for pre-operative information.

Before your appointment

  • Take all medication including inhalers as normal. If you have been prescribed GTN spray, please bring this with you
  • Arrive wearing clothes comfortable for exercising
  • Do not eat a heavy meal for 2 hours before your appointment
  • Do not take alcohol for 4 hours before your appointment
  • Do not take vigorous exercise for 30 minutes
  • Do not smoke for at least 1 hour prior

What will happen during your appointment

Before the exercise begins we will take a resting blood pressure measurement and look at the rate and rhythm of your heart with an electrocardiograph (ECG) which involves placing stickers on your torso. (Some people may need to have a small area of their chest shaved in order for the stickers to stick to the skin). Next we will perform a breathing test to assess the airflow in and out of your lungs. You will then be fitted with a face mask to measure your breathing rate and levels of certain gases and we’ll also take your blood pressure during the test. Just prior to the test a pulse oximeter will be placed on your finger to assess blood oxygen levels.

  • In some circumstances we will also take a sample of blood from your ear before and after the exercise.
  • You will then be asked to cycle on an indoor static bike. You will be encouraged to cycle for as long as you can whilst your body’s response to exercise is assessed. The test will last no more than 15 minutes, during which you’ll need to exercise to the best of your ability. Throughout the test the intensity of the cycling will gradually be increased.
  • When you have completed the exercise you will be monitored whilst you rest and your body recovers.
  • The whole testing process will last approximately 90 minutes

Are there any Risks?

The risk for CPET is the same as for mild-moderate exercise, the number of patients who develop symptoms is low (1:1000).

  • From our experience, due to the nature of the test occasionally patients may feel lightheaded
  • If one is required your blood sample will be performed by a trained practitioner and the risks kept to a minimum.
  • We will be monitoring you closely during the test, with continuous ECG, blood pressure and oxygen measurements. If you develop significant symptoms, we will stop the testing.

Who will be present at your appointment?

CUH Addenbrooke’s NHS Trust is a teaching hospital and therefore there may be occasions when a Student accompanies your Physiologist. We will always seek your permission first.

Test results

After your appointment your test results will be sent to your referring consultant. This can take approximately four weeks. They will then contact you to discuss the results and the next steps in your pathway.


You may be asked for consent to perform tests during your appointment. You will also have an opportunity to ask questions regarding the tests before you give consent. In the unlikely event there are risks related to the tests these will be discussed with you before the test starts.

If you can’t attend your appointment

If you need to rearrange your appointment, or no longer need an appointment, please call us on 01223 217065 as soon as possible to advise. Being able to reallocate appointments helps us to reduce waiting times.

Contacts/Further information

If you are unsure about any of the information provided in this leaflet or have any other questions then please do not hesitate to contact the Lung Function Department at Addenbrooke’s hospital on 01223 217065 or alternatively by contacting Clinic 2A on 01223 216645. Our opening hours are Monday-Friday from 08:30 to 16:30.

We are smoke-free

Smoking is not allowed anywhere on the hospital campus. For advice and support in quitting, contact your GP or the free NHS stop smoking helpline on 0800 169 0 169.

Other formats

Help accessing this information in other formats is available. To find out more about the services we provide, please visit our patient information help page (see link below) or telephone 01223 256998.

Contact us

Cambridge University Hospitals
NHS Foundation Trust
Hills Road, Cambridge

Telephone +44 (0)1223 245151