When it comes to getting exercise while pregnant, even your physician may have advised you to keep your heart rate at or below 140 beats per minute (BPM). However, the American College of Obstetricians and Gynecologists (ACOG) abolished this verdict years ago. "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.
If you're very fit, you may find that getting your heart rate above 140 BPM isn't particularly taxing – but if you're an exercise newbie, that number might be far too high. The bottom line, according to Lang: Pregnant women should work out at a moderate level.
How to know when 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.
If you really want to track your heart rate, use a monitor or measure your pulse for six seconds and multiply by 10. Here are the target heart rate guidelines for pregnant women by fitness level and age:
As long as you feel okay, it's probably safe to continue with the activities you were doing prior to pregnancy, including running and spinning, says Lang. You might just need to take the intensity down a notch as you get bigger.