Can You Run A Marathon While Pregnant? Experts Say It Depends

You may already know that, for most pregnant women, exercising throughout pregnancy is perfectly OK. However, not all exercise is created equal. Going for a long walk or taking a postnatal barre class is one thing, but running a marathon while pregnant is another. Training for a marathon requires a lot of work, dedication, and constant movement, and it’s not for everyone. Even if you want to push yourself, you may also wonder if it is even safe to run a marathon while pregnant.

Unfortunately, there is not a simple yes-or-no answer to that question. It depends on a few things: How pregnant you are, what your health is like, what your pregnancy is like, and how active you were before getting pregnant. Of course, you should always talk to your health care provider before engaging in any exercise, and that’s especially true for something as strenuous as running a marathon. But if you’re looking for some additional guidance, here’s what you’ll need to know if you want to run a marathon while pregnant.

Can you run a marathon while pregnant?

“In some cases, you can run a half or a full marathon during pregnancy, but that doesn’t always mean you should,” Alison Marie Helms, Ph.D, certified personal trainer and perinatal corrective exercise specialist, tells Romper. She goes on to note that, while running can be part of the moderate exercise recommended by the Centers for Disease Control (CDC) and American College of Obstetricians and Gynecologists (ACOG), you will not be able to go all out. “Be mindful of your ego/athlete mindset,” she warns. “Runners tend to push past boundaries, especially when it comes to training in the half/full marathon distances. Pregnancy is not the time to let your ego run the show.”

Running a marathon while pregnant is also something you should only consider doing if you’re an avid runner or have run marathons before — pregnancy isn’t the time to do your first marathon. “The concern is that anytime you do something new, your cortisol and other neurotransmitters will naturally be higher due to the activity’s novelty, which can place undue strain on the pregnancy,” explains Dr. Betsy Greenleaf, obstetrician and doctor of osteopathic medicine. “I would recommend not starting any new strenuous activities during pregnancy, as elevated cortisol levels can increase the risk of preeclampsia, miscarriage, and growth issues.”

But here’s the thing: Even if you’ve previously run a marathon while pregnant, that doesn’t mean you can necessarily do it again. “All pregnancies are different, even subsequent pregnancies for the same mother,” explains Helms. Always be sure to talk to your health care provider before you start training for a marathon or even a half marathon.

“Contraindications include high risk pregnancy, having not been accustomed to marathon training volumes before pregnancy, increased blood pressure, pain, and any other contraindication to exercise,” Helms says. “While running a marathon during pregnancy can be done safely with all of the recommendations it’s important to note that running long distances does not necessarily mean a healthier, fit pregnancy.”

Is it OK to run long distances while pregnant?

Generally, it’s safe to run long distances when you’re pregnant, according to Helms. That said, you have to remember that, you know, you’re pregnant. You may need to modify some things to keep your run safe for you and your baby. “You may need to cut down on your volume a bit to prioritize recovery,” Helms says. “Listen to your body and do what feels right.” She recommends focusing more on distance and pace rather than time and rate of perceived exertion.

If you’re pregnant and planning on running long distances, you also need to make sure you’re taking all safety precautions. Staying hydrated is the most important — Greenleaf notes that she’s most concerned about running long distances in terms of dehydration and the depletion of electrolytes. She recommends drinking lots of water and choosing foods that stabilize blood sugar both before and after running during pregnancy.

Can I run a marathon in the first trimester?

Many women don’t even know that they’re pregnant until they’re at least five or six weeks along, which means that they might do something they wouldn’t normally do while pregnant. If you’re planning to run a marathon but realize discover that you’re pregnant, or you run a marathon and later find out that you were already pregnant when you ran, there is no need to stress. Running a marathon in the first trimester is probably fine.

In this, the very earliest stage of your pregnancy, you might not even feel any pregnancy symptoms yet. If you’re going to run a marathon while pregnant, the first trimester is arguably the best time to do it — assuming you feel well enough and have already been in the habit of running long distances. That said, once you do know that you’re pregnant, it’s best to talk to your health care provider about any exercise program you hope to take on.

Tips for running a marathon during the first trimester

If you are planning to run a marathon during your first trimester, remember that pregnancy symptoms may affect your performance. “In the first trimester, the biggest concerns would be fatigue, morning sickness, and the risk of neural tube defects with overheating,” Helms says. If you’re set on completing the marathon in the first trimester, follow these precautions recommended by both Helms and Greenleaf:

• Take extra breaks and rest if needed
• Stay well hydrated and fueled with healthy foods
• Mind the weather conditions and don’t run if it’s too hot
• Watch for signs of overheating, like excessive fatigue, dizziness, and a rapid pulse
• Keep in mind that your bladder might feel full faster
• Consider buying new and more supportive shoes, keeping in mind that the relaxin hormone can cause your feet to change shape, making shoes fit differently
• Avoid running on uneven surfaces, as pregnancy can cause changes in your sense of balance that make you more susceptible to falls

Most of all, go easy on yourself and listen to your body. “Your body is going to divert resources to the baby no matter what,” Helms says. “However, under-fueling your body can set you up for injury with this level of mileage.”

Running a marathon while five months pregnant

At five months pregnant, you’re in the second trimester. Your belly is starting to grow, but those annoying first trimester symptoms — like nausea and extreme fatigue — have hopefully begun to dissipate. Both Helms and Greenleaf agree that it’s safe to run a marathon while five months pregnant as long as you were a runner before getting pregnant, take the proper safety precautions, and get clearance from your health care provider.

That said, running a marathon at five months is not exactly a walk in the park. “As pregnancy progresses, it’s highly likely you will experience changes in your running form,” Helms warns. “The biggest changes are usually a more pronounced anterior pelvic tilt (as the belly grows, your center of mass shifts forward), more external rotation at the hips (picture that pregnant waddle) which makes it harder to load effectively through midstance, and disruption of the rotation/counterrotation of the pelvis and torso (you are growing a human right in the middle of that system).” She suggests that, when preparing to run while in your second trimester, you should add specific strength training focused on your core, glutes, and rib cage mobility.

Running a marathon at five months pregnant may also impact the pelvic floor, so it is a good idea to add some pelvic floor strengthening and try to see a pelvic floor physical therapist at least once. “If you are experiencing symptoms of incontinence (urinary or fecal) or prolapse (heaviness, bulging or dragging feeling in your pelvis), it’s an indication that your pelvic floor is not handling the load well and it could be time to pull back on the running,” Helms says. You may also want to wear a belly support band to stay comfortable.

Benefits of running while pregnant

Whether you’re going out for a short jog or running a marathon, there are plenty of benefits making time for a workout while pregnant. Moderate exercise is great for both mom and baby. According to Helms, benefits include:

• Improved mood, energy, blood flow, and posture
• Less third trimester pain and less issues with moving around as your belly grows
• More support for the baby’s growth
• Reduced rate of gestational diabetes

Both running and strength training can be a great way to feel better while pregnant.

When to stop running while pregnant

It’s essential to be aware of warning signs to watch for when you’re running while pregnant. Stop running right away and contact your health care provider if you experience any of the below during or after a workout:

• Your heart rate is over 90 bpm
• You feel symptoms of overheating, such as excessive fatigue or dizziness. “Excessively increasing the core temperature of the mother, especially in the first trimester, can result in neural tube defects in the baby,” Helms says.
• You feel dehydrated. “Dehydration can result in complications for mom and baby, like preterm labor and decreased amniotic fluid,” Helms says.

You know your body best, so call your health care provider immediately if you ever feel “off” in any way after working out. Remember: Running a marathon at any point is a major undertaking, let alone taking it on while pregnant. There’s no shame in getting checked out if you think something could be wrong.

Sources Interviewed:

Alison Marie Helms, Ph.D, certified personal trainer and running coach, and pregnancy and postpartum corrective exercise specialist

Dr. Betsy Greenleaf, OB-GYN, doctor of osteopathic medicine, fellow of the American Congress of Obstetricians and Gynecologists, pH-D Feminine Health Advisor