What to Expect

Exercise Tests

What is an exercise test?

Most tests in the Heart Center are done while your child is at rest. But sometimes we need information about what happens when your child is active. An exercise test measures how your child’s heart and lungs respond to the demands of physical activity. 

Exercise tests include seeing how far your child can walk in a set amount of time and checking how their heart, lungs and muscles work together during exercise.  

Why is an exercise test done?

We use exercise tests to diagnose heart rhythm problems (arrhythmias), guide the type and amount of activity we recommend for your child and check your child’s overall fitness. Their fitness level may help us decide the best ways to manage their condition. Sometimes we do an exercise test to better understand risks for a child during exercise. 

What are the types of exercise tests?

The Heart Center Exercise Lab provides 3 types of tests.

6-minute walk test

During the test, your child will walk at their normal pace for 6 minutes, and we will record the distance they covered. We use the results to check how your child responds to treatment. Often, this means repeating the test later and comparing the results.  

Treadmill test

A treadmill test lets us check your child’s heart and blood pressure as they do harder and harder exercise. Your child will walk on a treadmill that slowly gets faster and steeper. They will wear electrocardiogram (ECG or EKG) stickers (leads) on their chest so we can check their heart rate and rhythm during the test. They will also wear a blood pressure cuff on their arm. The test stops when your child cannot keep going comfortably. A treadmill test is also called a simple exercise stress test. 

Cardiopulmonary exercise test (CPET)

A CPET is a test to see how well your child’s heart, lungs and muscles work together during exercise. It is a way to check your child’s fitness. Your child will do the test on a stationary bike or treadmill. The resistance from the bike or treadmill will slowly increase. Your child will wear ECG leads on their chest so we can check their heart rate and rhythm. A CPET also measures their lung volume and lung function while they are at rest and while they exercise. Your child will breathe through a mouthpiece or wear a facemask, similar to a snorkel. They will also wear a headband with a pulse oximeter, which checks the level of oxygen in their blood. The test stops when your child cannot keep going comfortably.   

How long is an exercise test?

You will be at the Exercise Lab for 1 to 2 hours. This includes time to set up, explain and do your child’s test and then monitor them as they recover. The exercise test itself takes only about 15 minutes. 

Is an exercise test risky or dangerous?

Every test has some risks, but exercise tests are typically low risk. We will carefully monitor your child at all times during their test. Our goal is for your child to exercise until they are too tired to keep going, but if there is a safety concern at any point, we will stop the test.  

What should we do on the day of the test?

  • Arrive for your appointment 15 minutes early at the Heart Center at Seattle Children’s Hospital in Seattle. 
  • Wear sneakers or athletic shoes that fit securely. 
  • Wear a short-sleeved T-shirt and athletic shorts or pants (clothes you might wear to P.E. class at school). 
  • Shower the day of the test or the night before.  
  • Eat a light snack 1 to 2 hours before the test.  
  • Drink at least 8 ounces of liquid (milk, water, juice or sports drink) 1 hour before the test. You may bring a water bottle to the test. 
  • Take your usual medicines unless we have told you not to. 
  • If you normally use an inhaler before, during or after exercise, bring it with you. 

There are a few things we ask you to avoid: 

  • Do not use body lotion until after the test.  
  • Do not eat a large meal within 2 hours of the test. 
  • Do not drink soda or anything with caffeine the day of the test. 

How should my child feel after an exercise test?  

Your child may feel a bit tired or even have sore muscles after the test. This is more common in children who are not used to exercising. Otherwise, your child should feel normal. They can go to school or do their usual activities for the rest of the day.

When will we get results from the exercise test? 

Results are usually ready within a week. They will be available in your child’s electronic medical record. The doctor who requested the test will go over the results with you. 

Contact Us

Contact the Heart Center at 206-987-2515 for a referral, a second opinion or more information. 

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