What's a Safe Heart Rate for Exercise During Pregnancy?

When it comes to getting exercise while pregnant, everybody seems to have an opinion about what is safe and what is not. You may have even heard that pregnant people should keep their heart rate at or below 140 beats per minute (BPM), but fortunately, the American College of Obstetricians and Gynecologists (ACOG) debunked this myth years ago.

There aren't precise "rules" when it comes to heart rate and exercise during pregnancy, but here is some insight that could help you determine what's best for you. And of course, always be sure to talk to a health care provider about your plans for working out during pregnancy.

Your Heart Rate During Pregnancy

One of the main reasons it can be difficult to track a "healthy" heart rate during pregnancy is that pregnancy itself majorly changes the demand on the heart and circulatory system.

Being pregnant means that your cardiac output (the amount of effort your heart has to put out to pump blood through your heart and body) increases by 30% to 50%. And the amount of blood you have in your body, called your blood volume, literally doubles as well.

The point is that pregnancy alone can raise your resting heart rate to higher levels than pre-pregnancy, so your heart rate while exercising during pregnancy will most likely be much higher than it was before you were pregnant, too.

Your doctor or midwife will keep a careful eye on your heart health, including your heart rate and blood pressure, during each pregnancy check-up, so be sure to keep all your scheduled appointments and keep your health care provider updated if you are having any discomfort with activity or exercise.

How High Is Too High for Your Heart Rate While Pregnant?

The short answer: The "safe" limit for a heart rate during pregnancy may be different for everyone.

"There isn't a hard-and-fast rule for heart rate anymore because it's not always a good indicator of how hard you're working," says Annette Lang, a New York City fitness expert specializing in pre and postnatal training. Additionally, everyone, pregnant or not, has an individual baseline heart rate that is different, so there is no one-size-fits-all for a healthy heart rate.

Your "target" heart rate, which the American Heart Association explains is something you can use to help guide your activity levels, also varies by age. For a non-pregnant person, your maximum heart rate is approximately 220 minus your age.

Your regular activity level also plays a role. For instance, if you've been exercising a long time or are an athlete already, you may find that getting your heart up isn't particularly taxing. But if you're an exercise newbie, even a slight increase could be uncomfortable.

Focus on Exercise Intensity Rather Than Heart Rate

Rather than focusing on a heart rate limit, pregnant people should work out at a moderate level in ways that they are used to exercising before they became pregnant, according to Lang.

How do you know if you're exercising moderately? Use the "talk test" as a measure of exertion: You should be slightly breathless but still able to carry on a conversation, says Jon Snyder, M.D., associate professor of obstetrics and gynecology at the New York University School of Medicine. If you're panting, slow things down. If you're able to chat easily, ramp your effort up.

Safe Exercises for Pregnancy

As long as you feel OK, it's probably safe to continue with the activities you were doing prior to pregnancy, including running, swimming, and spinning, says Lang. You may just need to take the intensity down a notch as your pregnancy progresses through each trimester.

Most importantly, be sure to listen to your body and do what's best for you and your baby. And when in doubt, consult a health care provider if you have any symptoms while exercising or experience cramping, fluid leaking, or pain.