Everything You Need to Know About Running While Pregnant

When Peloton instructor Selena Samuela first got pregnant with her son Torin, she had ambitious visions of running strong as her baby bump grew bigger and bigger. “I told myself, ‘You're going to be the kind of pregnant lady who is doing bootcamps and teaching interval classes on the Peloton Tread until you're ready to pop,’ ”she says. “I had this idea that I was going to feel great the whole time and be running well into my eighth month. But that didn't end up being my reality.” 

It’s impossible to predict how much you’ll be able to run during pregnancy until you’re actually in the midst of it. But one thing is clear: Doctors say that exercising while pregnant can be one of the healthiest things you can do—if your body and pregnancy allows it. Working closely with her OB, Selena ran until it was no longer safe. But even though she had to stop sooner than she would have liked, she says the weeks she did spend running gave her a whole host of benefits.     

If you’re expecting a little one and thinking about running while pregnant, read on to learn more about what running can do for you and your baby, and how to log your miles safely.

Can You Run While Pregnant?

Although doctors used to warn women against exercising during pregnancy—particularly when it came to high-impact workouts like running—today, the American College of Obstetrics and Gynecology (ACOG) not only allows exercising, but actively suggests it. “We recommend that patients exercise before, during, after pregnancy, as long as they don't have any contraindications,” says Dr. Nicole Sparks, MD, an OB/GYN in Georgia.

Is Running While Pregnant Safe for Mom and Baby? 

If you have a healthy pregnancy, running won’t increase the danger of miscarriage or early delivery, according to Dr. Sparks. But your doctor will likely advise against it if you are already at risk for a preterm pregnancy or have a condition like a placenta previa. Not sure whether running might be healthy for your particular pregnancy? Talk to your doctor. “Depending on what your specific issue is, we might tell you not to run altogether, or we might tell you just to run light,” Dr. Sparks says.  

Also: Just because you didn’t run prior to pregnancy doesn’t mean it’s too late to start now. Although an often repeated piece of guidance is that “if you did it before pregnancy, you can keep doing it,” Dr. Sparks says that doesn’t mean you can’t run if you didn’t run before pregnancy—you’ll just need to take it slowly and feel out how your body responds. “Even if you wanted to start a running program after you get pregnant, you're under really good doctor’s supervision and are going to see your doctor more frequently than if you weren't pregnant. So it's still a great time to start,” she says. “We don't want you coming out the gate running 10 miles, but we actually want you to run, if you can.” Dr. Sparks recommends starting with walking, and slowly progressing from there (more on that later).

As long as you’re healthy, have a normal pregnancy, and the green light from your doctor, you can start exercising. According to the ACOG, “If you are healthy and your pregnancy is normal, it is safe to continue or start regular physical activity.”

Another outdated myth is that you need to monitor your heart rate to keep it below 140 while exercising. That actually isn’t true. Dr. Sparks says that 140 is just an arbitrary number that ACOG came up with in the ‘80s, but ACOG later revised then eliminated it altogether from its guidelines. “If you feel comfortable, you can talk and you can breathe okay while you're running, that is okay,” Dr. Sparks says. Don’t worry—your baby will still be getting enough oxygen. The ACOG recommends gauging your exercise intensity based on your rate of perceived exertion or by using the talk test, as Dr. Sparks mentioned above (as long as you can talk and carry a conversation while exercising, then you’re likely at an appropriate intensity.)

How to Know How Much You Can Run

ACOG recommends that pregnant women get at least 150 minutes of moderate-intensity aerobic exercise per week through activities like running. Dr. Sparks suggests splitting that up into about 30 minutes over five days. “I don't really want you out there running for two hours,” she says. 

However, she says that how much you run depends on your fitness level. If you’re a regular marathon runner who’s used to long runs and you haven’t had any health issues, running more than 150 minutes a week shouldn’t be a problem. This is where the “keep doing what you were doing” advice comes in. Longer runs are safe for expecting mothers who often run long “because they've been training the whole time,” Dr. Sparks says.  

On the other hand, if you’re a newbie who’s just looking to start a running habit, Dr. Sparks will recommend you begin just by walking, then add in some short running intervals into your walks until you feel comfortable running for longer stretches. “You want to do a gradual progression,” she says. 

When to Stop Running During Your Pregnancy

“If you are getting to the point where you're having really bad pains, you're getting contractions, if you're bleeding, anything that's worrisome, you're going to want to talk to your doctor,” she says. These issues don’t always mean that you need to quit running cold turkey. Depending on what’s going on, you might just need to shorten your runs or go a little easier. “But if it's something serious, we will tell you just to stop altogether,” Dr. Sparks says. 

Around 20 weeks, Selena says she started experiencing cramping and pain in her lower abdomen whenever she ran. “It was a decently acute pain, and it was scary,” she says. “When I described the experience to my OB, she and I both felt that to be safe it was probably a good idea to stop running.” Although she was frustrated to have to give up running just halfway through her pregnancy, she knew it was the right choice for her and her baby.

The Benefits of Running While Pregnant

Dr. Sparks says the benefits of running while pregnant are “endless.” Here are some of the biggest ones. 

Lower Chances of Pregnancy Complications

Staying active through exercises like running can help you have a healthier pregnancy. “It decreases your risk of preeclampsia, gestational hypertension, gestational diabetes,” Dr. Sparks says.   

Eases Constipation

Between hormonal changes and a growing fetus, it can be a struggle to stay “regular” during pregnancy. One of the most natural ways to keep those bowel movements coming is to stay active so that your stool doesn’t just sit there in your GI tract. Both running and yoga are known to aid digestion.  

Can Improve Your Mental Health

The U.S. Department of Health and Human Services says activity during pregnancy can boost your mood, improve your focus, and reduce your stress. “Running did for me the same as it does for me when I'm not pregnant—it's one of the things I do for release. It's meditative for me,” Selena says. “I'm always in a great mood after a run!” 

This remains true after you’ve given birth, too. “Studies have shown that exercise can actually help decrease the chances of postpartum depression,” Dr. Sparks says. 

Can Potentially Give You a Smoother Delivery

“I pushed Torin out in 30 minutes,” Selena says. “I like to chalk that fast delivery up to being strong and fit before and during pregnancy, so in my mind I give running some of the credit for that!”

Although fitness by no means guarantees an easy delivery, it can potentially help. Dr. Sparks says that staying active through activities like running can decrease your risk of cesarean delivery, and increase the chances that you'll have an easier labor. 

What Are the Risks of Running During Pregnancy?

Before you head out for a run while pregnant, there are a couple of potential risks to be mindful of. 

Trips and Falls

Dr. Sparks says the biggest worry doctors have about running is making sure you stay upright. “You have this big bowling ball that's in front of you,” Dr. Sparks says. “Your balance is off. Sometimes you can't see.” According to the Mayo Clinic, a bad fall that directly hits the belly after 23 weeks of pregnancy could cause complications like contractions or a loss of amniotic fluid.  

Decreased Blood Flow to Baby

Although doing an easy-effort run at moderate intensity is healthy and safe, doctors warn against sprinting your absolute hardest. “If someone's overdoing it, you can potentially decrease utero placental blood flow. And that's what people are worried about during pregnancy,” Dr. Sparks says. This decreased blood flow could lead to stunted growth, preterm labor, or miscarriage. “But that does not happen unless you are really at the upper limit of your heart rate and your breathing during pregnancy, which most people are not going to do,” Dr. Sparks says. 

Tips to Safely Run While Pregnant

So, how can you run safely—and comfortably—during pregnancy? Keep these tips in mind. 

Embrace Easy Jogging

Pregnancy is not the time to start doing hard tempo workouts. Stick with easy-effort runs where you feel like you could have a conversation. “If it's to the point that you’re getting super short of breath, you can't really make any words out, that's when you should probably cut back a little bit,” Dr. Sparks says. “I would focus on just a nice, light jog.”

Skip the Trail Runs

Save gnarly single-track trails full of rocks and roots until after delivery—you want to steer clear of any obstacles that could lead to a fall. “Your balance is going to be a little bit off the bigger you get,” Dr. Sparks says. 

Stay Hydrated

Drinking enough water during pregnancy is essential to make sure that there’s ample amniotic fluid around the fetus and that your body is efficiently circulating nutrients. Since you’ll be sweating, Dr. Sparks suggests keeping a close eye on hydration before, during, and after your runs. 

Avoid Overheating

If it’s hot outside, do a treadmill workout. Especially in the first trimester as the fetus is developing, Dr. Sparks says experts encourage staying in safe temperatures. Research shows that heat exposure has been linked to preterm birth. 

Wear a High-Support Sports Bra

Hormonal changes during pregnancy can make your breasts grow by one or two cup sizes—and feel sore right up until you give birth. Invest in a quality high-support sports bra for running while pregnant so that you aren’t held back by the extra bouncing. ACOG says a pregnancy support belt can also be helpful for your belly later in pregnancy.

Eat Before You Run

Make sure to have at least a few bites before you hop on that Tread. “If you’re not taking in enough calories, you could get hypoglycemia,” Dr. Sparks says. Low blood sugar is more common during pregnancy because the hormones change how we process sugar. If it dips too far, you could start to feel shaky or weak.

Don’t Push Through Any Pain

Even more than usual, pregnancy is a time to really listen to your body. If something hurts while running or just doesn’t feel right, pull back and ask your doctor whether it’s safe to continue lacing up.   

How Being Pregnant Can Affect Your Run Performance

If you’re planning to set a new PR while you’re pregnant, well, you might want to adjust your expectations. A whole host of changes happening in your body will naturally slow you down. 

For starters, you might not feel up for running the way you used to. “I had a lot of nausea in the early afternoons in my first trimester, and my energy levels were different,” Selena says. Her strategy was to get her runs in earlier in the day before the exhaustion and nausea set in.

Even when you do feel like running, know that you’ll be panting sooner than usual, especially as the pregnancy progresses. “You're naturally going to get short of breath as the uterus gets bigger and pushes the diaphragm,” Dr. Sparks says. 

Our joints also become more mobile during pregnancy, thanks to relaxin, a hormone that’s released to help your pelvis expand for labor. This means you might feel extra sore after a run, and will be more susceptible to injury. And between relaxin, weight gain, and your shifting center of gravity, your gait will likely feel a bit foreign. 

The Takeaway

There’s no one-size-fits-all recommendation for running while pregnant. “Just like every pregnancy is different and every body is different,” Selena says, “everybody's relationship to running while pregnant is going to be different.” According to Dr. Sparks, your starting fitness level and your individual pregnancy needs will affect what experts say is safe and healthy. “Which is why we tell everybody to talk with your doctor first,” she says. 

Whatever your pregnancy running journey looks like, stay flexible and adapt as your body changes. Looking back, Selena wishes she’d been kinder to herself when she realized at 20 weeks that she wouldn’t be able to run again until after delivery. “I remember being really bummed out about it because I had friends who were further along and still running and feeling great,” she says. “It was really hard to come to terms with that at first.”

She says her biggest piece of advice for expecting mothers is to not put any pressure on yourself. “It's tough enough as women to live up to the bloated expectations society and media has created for us,” she says. “We should give ourselves and our baby the grace and the space that we need to work through this wild journey in a present and peaceful way.”

This content is for informational and educational purposes only and does not constitute individualized advice. It is not intended to replace professional medical evaluation, diagnosis, or treatment. Seek the advice of your physician for questions you may have regarding your health or a medical condition. If you are having a medical emergency, call your physician or 911 immediately.