(HealthDay News) -- A cardiac stress test gives doctors an idea of how your heart functions at rest and when it's under "stress" from activities such as treadmill exercise.

The U.S. National Heart Lung and Blood Institute says you can prepare for the test by:

• Dressing comfortably in workout clothes, including footwear designed for exercise.
• Checking with your doctor to see if you need to avoid food and water before the test.
• Checking with your doctor, if you're diabetic, to see if you should adjust your medication before the test.
• Asking your doctor if you need to avoid caffeinated beverages, certain foods or over-the-counter medications before the test.
• Bringing any inhaler you use to the test and letting the doctor know about it.