The newest guidelines from the American College of Obstetricians and Gynecologists suggest a pregnant woman should use her Rate of Perceived Exertion (see image below) or the Talk Test. A pregnant woman’s heart rate fluctuates throughout gestation, therefore making it difficult for you to determine from a number on a heart rate monitor just how hard your body is actually working. This is why Rate of Perceived Exertion and the Talk Test can be more effective.
In 1985, ACOG conducted a study that resulted in their recommendation of 140 beats per minute as the maximum heart rate for a pregnant woman who is exercising. In 1996, the ACOG rescinded this guideline. Currently, research still recommends not exceeding the 140 BPM, as seen on the Borg Scale below. Please note that you should always follow your doctor’s protocol.
As mentioned above, in April 2020 ACOG determined that perceived exertion is a more effective way to monitor intensity than heart rate monitors. While the talk test is another fantastic way to measure exercise intensity during pregnancy! Fun note: If you have are an avid exerciser, you might recognize you are pregnant because your normal routine has your RPE or heart rate going higher than usual.
A handful of research articles including the IOC’s Exercise and Pregnancy in Recreational and Elite Athletes suggest pregnant athletes should use a heart rate monitor as an additional tool because athletes tend to “push” through.
It’s important to pay attention to how hard you are working during pregnancy exercise, or your rate of perceived exertion. Use the Talk Test, speaking a full sentence while exercising. Or the Borg Scale.
ACOG recommends the 15-point scale, while other research recommends a 10-point scale. For moderate intensity exercise you should be between 12-14 or “somewhat hard” on the Borg scale.
Measuring exertion through the talk test is one of the easiest ways to determine what’s too much and what’s too little. As long as you can carry on a conversation while exercising you are likely in the sweet spot and not overexerting yourself.
Takeaway: The use of perceived exertion can be a more effective way to determine intensity during pregnancy, unless you are an athlete with longer training sessions – more on that below.
Please see the Prenatal Exercise Do’s & Don’ts before beginning prenatal exercise.