A stress test is a way of measuring how well your heart works under greater demands — namely, exercise. Some doctors will call this an exercise test or treadmill test. A doctor or healthcare professional may order this test for a number of reasons, including assessing your exercise tolerance, determining if your heart can respond to exercise demands, or if medications you’re taking to improve your heart condition are working.

When you get your stress test results, a doctor will compare your results with ones of other people your age. Keep reading to find out more about your stress test results based on your age.

During a stress test, a doctor will monitor several key vital signs. These include your:

  • heart rate
  • heart rhythm
  • blood pressure

A doctor will also assess your symptoms during the test, asking you to report symptoms such as chest pain. Doctors are specifically looking at your vital signs for ischemia, or poor oxygen and blood flow to the heart.

Doctors may use different scales to report your results. Some stress test results will simply say “positive” (meaning there was something concerning about your stress test) or “negative” (meaning your stress test was normal).

It’s possible a doctor could declare your test nondiagnostic. This is true if you can’t achieve 85% of your maximum heart rate but don’t experience any electrocardiogram (EKG) changes that suggest you’re experiencing ischemia.

Another stress test calculation is the Duke treadmill score. The key components of this score include:

  • exercise duration in minutes subtracted by
  • five times the standard deviation of the ST-segment on an EKG subtracted by
  • four times the angina index (where 0 = no angina; 1 = non-limiting angina; and 2 = angina-limiting exercise)

If your score is less than or equal to −11, you’re at high risk of cardiac complications. If your score is −10 to 4, you’re at intermediate risk of complications, and if your score is greater than 5, you’re at low risk.

Most doctors follow the Bruce protocol for stress testing. This involves starting on a treadmill at a speed of 1.7 miles per hour and a 10% incline. The person assisting you with your test will increase the speed and angle of the incline every 3 minutes until you reach your target heart rate.

The likelihood of an abnormal stress test result increases as you age. A study of athletes had the following findings:

  • Of those ages 35 to 60, 5.1% had an abnormal stress test.
  • Of those older than 60, 8.5% had an abnormal stress test.

When you exercise for a treadmill stress test, a doctor will identify a target heart rate. Your age is a significant determining factor for this heart rate. Most doctors will challenge you to exercise at such a level you achieve 85% of your age-related maximum heart rate.

Maximum heart rate is calculated by subtracting your age from 220.

This means the following will be your expected stress test heart rate by age:

Your ageMaximum heart rateTarget heart rate (85% max)
20200170
30190162
40180153
50170145
60160136
70150128
80140119

Factors a doctor is looking for while your heart rate goes up include:

  • if you have chest pain while you exercise
  • if you have EKG changes that indicate your heart isn’t getting enough oxygen
  • if your blood pressure goes up too much

A doctor considers your test positive for ischemia (not enough blood flow to the heart) if you have at least a 1-millimeter horizontal or down-sloping ST-segment depression or elevation.

If you’re feeling confused about the results of your stress test, you’re not alone. The following are some commonly asked questions about stress tests.

What do doctors look for in a stress test?

Doctors are essentially looking for how well your heart is working overall in a stress test. They may also be checking to see if medications are working as expected or if you need further, more invasive testing (such as a coronary angiogram).

How many minutes is good on a stress test?

A stress test involves walking on a treadmill until your heart rate reaches an established rate based on your age. If you’re able to achieve this without signs of poor oxygen flow to your heart (ischemia), the stress test is over.

One study of those older than age 75 found the average test times for people ages 76 to 80 were:

  • 7 minutes and 22 seconds for men
  • 6 minutes for women

How do transgender people fit in?

At the time of publication, no studies could be found that spoke to stress test results among the transgender and gender nonconforming population.

As a trans person, your expected results will depend on whether or not you’ve chosen to pursue hormone replacement therapy as well as a variety of other factors. Talk with a doctor if you’re concerned about the results of your stress test.

Learn more about how trans people fit into clinical trials.

Can anxiety affect a stress test?

Anxiety can be a risk factor for cardiac disease. However, one study of men and women set to undergo stress testing didn’t find anxiety was predictive of a positive result. The researchers did theorize that increased anxiety could activate the sympathetic nervous system, which can increase the heart rate (and make you feel more anxious).

Ideally, you’d rather be calm and not anxious on the day of a stress test. However, researchers haven’t proven that anxiety worsens stress test results.

Learn more about ways to reduce anxiety before your test.

Can you pass a stress test and still have a blockage?

Cardiac stress tests are usually sensitive to blockages that obstruct 70% of a heart’s artery or more. This means it’s possible you could have heart disease that isn’t yet causing symptoms on a stress test.

The only true way to know if you’re concerned about heart blockages is to undergo a coronary arteriogram.

Does a stress test show all heart problems?

A stress test is a noninvasive way to help a doctor estimate how well your heart is working. The test results could indicate if you aren’t experiencing the kind of blood flow to and from your heart that’s expected.

However, the stress test doesn’t let a doctor identify where your blood flow is affected, which more invasive testing could. Talk with a doctor if you’re concerned about your need for further testing.

What should I eat right before a stress test?

A doctor will direct you on how long you should wait to eat before your stress test. You’ll usually refrain from eating or drinking anything besides water for 2 to 4 hours before your stress test.

Should someone accompany you to a stress test?

It’s a good idea for someone to come with you to a stress test. This is because if you do have a positive result or are simply worn out from the test, having someone to drive you home can be beneficial and safer.

A doctor will take into account your age when determining an appropriate heart rate for you to achieve during a treadmill exercise stress test. While the incidence of a positive stress test goes up as you age, a positive test is abnormal regardless and indicates the need for further testing.

Even if you’ve had a negative stress test, you could still be at risk of ischemia and heart problems. Always get immediate medical attention if you experience chest pain or discomfort.