Your child's doctor has asked that your child complete a VO2 max exercise test. This information explains what the test is, how to prepare for it and how it is done. Parents can use this information to help their child prepare for the test.
What is an exercise test?
The exercise test tells your child's doctor if your child's heart beats in a regular way when they do things like walk, run and ride a bicycle. These tests give information your child's doctor cannot measure while your child sits or rests. The doctor can also see how your child's heart works compared with how other children's hearts work.
What is the VO2 max exercise test?
The VO2 max exercise test measures how well your child's heart and lungs send oxygen to the muscles during heavy exercise. Your child will be asked to either pedal a special bicycle or walk on a treadmill, which is like a moving sidewalk. Your child's heartbeat, blood pressure and oxygen level will be measured while they exercise.
Your child should sleep well and eat a good breakfast before the test
To get ready for the exercise test, your child should do the following:
- Your child should be well rested the night before the test.
- Your child should eat a good breakfast on the day of the test. A good breakfast includes servings of grains, protein and fruit. One example of a good breakfast is egg, peanut butter or cheese; toast; juice or fruit; and milk.
- Your child should finish eating one to two hours before they start the test.
- Your child should wear or bring a T-shirt, shorts, non-slip, closed toe, running shoes and socks for the test.
Who will give the test?
Two technologists will give your child the VO2 max exercise test. Technologists are people who are trained to give the test on the machines in the hospital.
First your child will be asked to do a breathing test
Before the VO2 max exercise test, your child will be asked to do a breathing test called a pulmonary function test. The pulmonary function test is done in two parts:
- The first part of the test is like blowing out the candles on a birthday cake. It measures how much and how fast your child can blow air out.
- The second part of the test measures how much air your child can breathe in and out in 15 seconds.
Before the test, your child will be given a clip to put on their nose. The nose clip makes sure that your child's breath comes out only through the mouth. It also makes it easier to measure the amount of air going in and out of the mouth.
Your child will be given a mouthpiece to blow in. Your child will breathe through the mouthpiece into a machine called a spirometer. The spirometer measures your child's breathing.
These tests use a clean, sterilized mouthpiece and nose clip.
Machines will measure your child's oxygen levels, blood pressure and heartbeat
To prepare your child for the VO2 max exercise test, the technologist will do the following things:
- The technologist will put a device called a saturation monitor on your child's forehead. It measures the amount of oxygen in your child's blood. The device is kept in place with a headband.
- The technologist will put a sleeve called a blood pressure cuff on your child's arm. The blood pressure cuff will be used to check how hard your child's heart is pumping during the test.
- Your child will be hooked up to a computer called an electrocardiograph (ECG). The ECG makes pictures of how your child's heart beats during physical activity.
Connecting your child to the ECG
Here are the steps the technologist will follow to hook up your child to the ECG:
- The technologist will wipe the skin on your child's chest with water. This is to make sure the skin is very clean.
- The technologist will gently rub the cleaned skin with a scratchy pad. This will make it easier for the stickers to stay on and provide a good picture of your child's heartbeat.
- The technologist will put 10 stickers, called electrodes, on your child's chest.
- The technologist will attach one end of a wire to each electrode and the other end of each wire to the ECG machine.
Your child will ride a special bicycle or walk on a treadmill
Most VO2 max exercise tests are done on a special bicycle, but sometimes the test is done using the treadmill. If your child is using the bicycle, the technologist will adjust the seat to fit your child's height. The bicycle does not move and your child does not have to balance on it.
Before starting the test, your child will be given a nose clip and a rubber mouthpiece to breathe into. The mouthpiece is connected to a machine called a metabolic cart. It tests how well your child's body takes in oxygen and sends it to the muscles.
The technologist will then tell your child how fast to pedal. It will feel like riding a bike up a hill that gets steeper and steeper. Your child will be asked to pedal for between five and 10 minutes.
When your child cannot pedal any more, the technologist will make the bike easier to pedal. After one minute the technologist will remove the mouthpiece and nose clip. Your child will then be asked to pedal slowly for two minutes to cool down.
Your child's heart rate and blood pressure will be monitored at rest, during exercise, and during the cool down period.
It is important that your child follows the directions the technologist gives for the test. Encourage your child to try their best. This way, the doctors can get the most accurate results. They will have a clearer picture of your child's heart and how it works.
Your child should let the technologist know if they have problems during the test
Your child should let the technologist know right away if they have any problems during the test. The technologist will show your child how to use hand signals. Your child can use the hand signals to let the technologist know if they have any of the following problems:
- pain in the chest
- trouble breathing
- dizziness
- heartbeat feels irregular
- tired legs
If the technologists see a problem during any of the tests, they will tell the cardiologist right away.
You may be able to stay with your child during the test
You can discuss with the technologist if it is best for your child if you stay. You must not talk to your child during the test so that they can concentrate.
You will hear about the test results in 10 to 14 days
A cardiologist who specializes in reading exercise tests will look at all of the information from the test and write a report.
Your child's cardiologist will get this report of the test results in about ten to 14 days. You will get the results from your child's cardiologist.
If you see your child's cardiologist on or shortly before the day of the test, they will tell you how and when you will get the test results.
At SickKids
The test is done on the 4th floor of the hospital on ward 4B. Please register at the 4B desk.