The CPET involves monitoring your heart and lungs while performing exercise. Your heart rate and rhythm, blood pressure, breathing rate, the amount of oxygen you use and how much oxygen is in your blood will all be recorded.
To perform the test, you will use an exercise bike. To monitor your heart, sticky patches called electrodes will be put on your chest. An inflatable cuff on your upper arm will measure your blood pressure and a soft, comfortable facemask will monitor your lungs.
You will start by cycling at a steady pace with only light resistance. The bike's resistance will increase gradually every few minutes as you maintain the same pace. You’ll keep cycling until you are told to stop or until you are unable to carry on. Most people find their legs give out first.
Some people worry about “doing well”. While you will be exerted, most of the test is performed within your comfort range with only the final minute or so pushing your heart and lungs hard.