UPDATED June 21, 2023: When it comes to running while pregnant, a lot has changed. For a long time, if people saw a pregnant woman running, well–she might as well be smoking a cigarette or eating sushi while drinking coffee and wine. Now, most people know you can run while pregnant and that it’s safe.
It wasn’t that way when I was pregnant with my first, though. Early in my pregnancy, my husband ran the Leadville 100 ultra-marathon. While he was lost in the woods (literally speaking), I passed the time trail running while pregnant—at probably an altitude of 11,000 feet. I mentioned this to Jake and he went kind of nuts—“Was the baby even getting oxygen? That was not safe!” he said angrily.
To ward off future heated discussions of this ilk about my running while pregnant, we talked with my doctor who set parameters so that Jake and I both felt like running while pregnant was good for the baby and me.
Thankfully, I was able to run through both of my pregnancies. My body ended up being the one to set the parameters for what was too much. My volume naturally decreased and for my second, I ended up cross-training for the last few weeks.
Running while pregnant concerns
If you are pregnant and want to run, there are a lot of questions. After all, running is stressful on the body. And, you want to be careful not to tax yourself too much when your body is already busy doing something super important–growing a human.
Don’t worry, I got you covered. I talked with experts, did the research, and chatted with other mother runners to develop this complete guide to running while pregnant. I also did it twice myself and coach pregnant athletes.
In this article, I’m going to cover:
You can run while pregnant! But your body will feel different. Pregnant running is not a time to chase personal bests.
- common questions about running during pregnancy
- how to run while pregnant
- when to stop running during pregnancy
- a trimester-by-trimester guide for pregnant runners
- 10 expert tips for running while pregnant
- So, let’s get moving!
Can you run while pregnant? It is safe to run while pregnant?
Yes, you can run while pregnant and it is safe.
In 1985, guidelines by the American College of Obstetricians and Gynecologists (ACOG) recommended pregnant women avoid high-impact exercise, activities raising the maternal heart rate to exceed 140 beats per minute, physical activity longer than 15 minutes, and physical activity allowing the maternal core body temperature to exceed 100.4° F.
However, in 1994 the ACOG removed all restrictions on maternal exercise. Then, in 2002, it recommended that expectant women exercise for 30 minutes on most or all days of the week. Finally, in 2020, the ACOG outlined the various benefits of exercise for pregnant women.
There is a theoretical concern of a heightened possibility of joint-related injuries in pregnancy due to the hormone relaxin. However, research has not shown an increase in exercise-related injuries, and in fact, exercise has been shown to decrease the rates of musculoskeletal complaints during pregnancy.
(By the way, one of my athletes qualified for Boston while pregnant. You can read her reflections on the process on my Instagram here.)
How far can you run while pregnant?
You can run as far as your body will let you when pregnant. In fact, I have had athletes run marathons while pregnant.
The key to this is scaling your intensity (you are not running as fast or as hard as you would if you weren’t pregnant) and that your body was used to doing this before.
I would not coach a pregnant runner to run a marathon if she hadn’t ever run a marathon. You do what your body was already used to doing when it comes to running while pregnant. Most often, a pregnant runners’ ability to run long distances will naturally be reduced as her body gets bigger.
Unless you are experiencing lots of morning sickness, a runner can run long distances while pregnant comfortably in the first trimester.
Can I run a marathon while pregnant?
Yes, you can run a race while pregnant, including running a marathon while pregnant. I have coached several pregnant women through marathons. However, racing during pregnancy is not a time to try to set a personal record. Running a race should be something done for the pure joy of the experience, not for setting PRs.
The largest study ever completed on pregnant runners supports that running while pregnant is safe, including running distances up to a marathon.
Training for a race while pregnant will look different. Effort will be scaled as it takes longer to recover while pregnant and it is harder to run faster the larger you get. (See below for training considerations).
Is it OK to start running while pregnant?
Running is safe for pregnant women unless you have medical conditions that prevent you from doing so. However, it is not advised to begin running while pregnant. In most cases, you should only run while pregnant if you were running before you became pregnant.
What exercises should you avoid when pregnant?
You want to avoid exercises that require you to lay on your stomach (like a Superman) or do jarring movements and extensive jumping such as plyometrics during pregnancy.
Read what exercises you can do while pregnant here.
Related: Pregnancy Core Workout
What are the health benefits of running during pregnancy?
How does running affect a fetus and mother? Running while pregnant has a lot of physical and mental benefits for the mother and baby. For example, studies show running while pregnant reduces the risk of preterm birth, pre-eclampsia, gestational diabetes, the need for a C-section, and high birth weight. It can also increase a baby’s brain development.
For example, running during pregnancy has been shown to:
- improve or maintain physical fitness,
- promotion of exercise in adult offspring
- help with weight management,
- reduce the risk of gestational diabetes,
- enhance physical well-being,
- decrease the incidence of urinary incontinence, pre-eclampsia, lower back pain, and the occurrence of Caesarean section, and, have increased energy and improved sleep.
There is also a huge component of self-esteem for women who run during pregnancy. Exercise is good for the mood in general and it can help with a changing body and moodiness from hormonal fluctuations.
In an unofficial poll of mother runners, moms who practiced running during pregnancy stated many benefits:
- More energy
- Easier and quicker delivery
- Increased feelings of ownership of their bodies
- Increased sense of normalcy throughout pregnancy
- The knowledge that we can do hard things
- A decrease in morning sickness
- Heightened mental and physical endurance
- Learned importance of breath
- Healthier pregnancy
- Quicker postpartum recovery
Related: Postpartum Running Plan
Can running while pregnant hurt the baby?
Running while pregnant cannot hurt your baby. Your body will tell you long before there is a real risk of limited oxygen or overheating.
Instead, research shows numerous benefits to the baby of mothers who ran while pregnant.
- A 2011 study showed an improvement in fetal development including more lean muscle mass, increased attentiveness, heightened discipline, and more neurodevelopmentally advanced.
- Another study reported an increase in lean body mass in infants of mothers who exercised as well as seeing improved stress tolerance in these babies.
- The improved stress tolerance is of particular importance as “it relates to labor and delivery and the infants’ ability to handle both while maintaining reassuring heart tones,” note the researchers.
- Another study, performed with rats and not people, found that the babies of exercising mothers had improved memory.
- The benefits of running during pregnancy can set your child up for a life of good health which is really cool. According to research. if you run during your pregnancy, your child is more likely to be active into their adult years.
Can running while pregnant cause a miscarriage?
No. High-level exercise and running cannot cause a miscarriage. Research has shown that miscarriage cannot be prevented, and thus cannot be caused, according to Acadia Gantz, an ultra runner, run coach, and midwife based in Maine who has conducted research into pregnant high-level athletes, shares key insights into the benefits running has for babies and their mothers.
When should a pregnant woman stop running?
A pregnant woman should stop running due to a medical concern and a recommendation by her doctor, or if running while pregnant feels uncomfortable.
Signs you should stop running during pregnancy or reduce volume and intensity of running during pregnancy:
- if you are struggling to recover between sessions
- if you have any leakage or pelvic floor discomfort (including round ligament pain)
- if you start experiencing pain in your knees, feet, back, etc
- your days demand a lot of energy and time on feet, and
- your energy starts to feel low
In most cases, your body will tell you that it is time to stop running due to discomfort or pain. Personally, sciatic pain during my second pregnancy in the third trimester told me it was time to call it quits for a while so I did barre instead.
It is time to stop running during pregnancy if you have any of the following medical conditions:
- placenta previa
- bleeding like subchorionic hemorrhage
- pelvic pain, particularly in the pubis symphysis
- significant incontinence (not just minor leaking)
What to expect running while pregnant
Running while pregnant will not be the same as running when you aren’t pregnant. Just call me Captain Obvious. I’ve run while pregnant and coached pregnant runners so I know this to be true.
When running while pregnant, you can continue to train but your body will provide a natural progression of difficulty and intensity. Here are some training tips to adapt to running while pregnant.
Training Tips to Run Pregnant
Run a big base phase.
Pregnant runners looking to stay fit or who want to race while pregnant, can run a big base phase which helps increase endurance. It’s important to note that recovery takes longer in between training sessions and races for pregnant runners.
Intensity will naturally be higher for pregnant runners. Therefore, it’s important to scale effort for workouts. For example, tempo runs may be done at a steady state pace instead of threshold. Intervals may be done at threshold pace rather than VO2 Max.
Volume will also be reduced and recovery intervals increased. Effort should not go beyond an 8/10 on the rate of perceived exertion scale (or 75 percent of your max heart rate). Avoid all-out strenuous exercise.
Hills are a wonderful training tool for pregnant runners because there is less impact. Therefore, it’s aerobically challenging but not overall taxing on the body (especially as relaxin production increases). Some pregnant runners may get breathless doing hills.
If so, then you should scale them or not run them as no session should be more than moderately hard.
If you are running a race while pregnant or still doing speed workouts, do one per week. Remove this weekly workout if you:
- are struggling to recover between sessions
- have any leakage or pelvic floor discomfort (including round ligament pain)
- did not do hard workouts before pregnancy
- are experiencing pain in your knees, feet, back, etc.
- you have high demand of energy/time on your feet during the day
- your energy starts to feel low
What to expect running during pregnancy by trimester:
First trimester running:
The biggest changes for pregnant runners in the first trimester are fatigue and morning sickness.
Fatigue: Take naps when the mood strikes. Also, be okay to take walk breaks or shorten your runs if you are exhausted. You aren’t doing anyone any favors by pushing through exhaustion (or pain).
Morning sickness: Stay hydrated and eat a small snack of carbs and some protein before you run. Some ideas include some yogurt and graham crackers or a spread of nut butter with a bagel.
Honor recovery: Running recovering for pregnant runners takes longer, so you may need to run every other day or take more time off in between sessions. Pay attention to how you feel.
Second trimester running:
In the second trimester is when your belly is starting to get bigger, and ligaments loosen thanks to the hormone relaxin. However, your energy levels will be up, especially compared to the first trimester.
Balance: Your center of gravity will increasingly change as your belly grows. Aim to run on level surfaces. Be careful as you make turns. Avoid running on snow or ice. Pay attention to how your body feels always.
Support: A belly band will reduce belly bouncing and provide support to your back. I review several belly bands for pregnant runners here. A maternity sports bra will also provide more support and make you more comfortable. I review nursing sports bras and sports bras for bigger chests here.
Relaxin effects: The hormone relaxin will make your joints, ligaments, and muscles looser. This can predispose you to injury. If you have pain or discomfort, including round ligament pain, do you not push through it. Scale back and talk to your doctor. (Pelvic tilts can help round ligament pain.)
Work on the core and floor: Continue (or begin!) working on your pelvic floor and deep core strength through a program such as ReCORE which has at-home prenatal and postnatal programs. It is also a good idea to meet with a pelvic floor physical therapist.
Third trimester running:
The third trimester is when many pregnant runners start to feel uncomfortable. Your body will tell you where your limits are. I remember for my pregnancies, I capped my runs to 4-mile run/walks in the third trimester (with lots of potty stops) due to body changes such as my growing belly, fatigue, and back pain.
Listen to your body: Continue to do all you’ve been doing to safely run while pregnant. Pay extra attention to how your body is feeling. If your runs are increasingly becoming too uncomfortable, I advise finding something else that moves your body but in a pain-free way.
I did barre and the elliptical for the end of my second pregnancy because I had back pain.
You can get more cross-training ideas here.
10 Expert Pregnant Running Tips
Here are ten practical tips to run pregnant from experts and mother runners who have done it to keep you safe and comfortable.
1. Talk to your doctor.
Every pregnancy is different. You may have complications or feel different than other Mother Runners. Whatever you do, make sure you tell your doctor that you’re continuing to run so that they can monitor how that’s going for you and the baby. Also, ask them to set guidelines like mine did—sharing your running history so they know what your body is used to doing.
2. Listen to your body.
If something doesn’t feel good or feels strange. Stop doing it. And, then share with your doctor what’s going on. Mother Runners advise not to push yourself hard. This is not a time to do speedwork and long runs. (Plus there is an increased risk of injury because of the relaxin hormone that’s pumping through your body getting it ready for birth—link). The comfort zone is the place to be when growing a human. Keep it easy. You’ll get it back.
3. Master the art of peeing outside (or find bathrooms).
I cannot tell you how many times I would have to pee (or at least felt like I had to pee) on a 4-mile run. I got really good at pretending like I was tying my shoe but instead was…well, you get the picture. Humility goes out of the door in the name of comfort. If this isn’t something you want to do, plan to run near public bathrooms.
4. Get a maternity support belt.
When the extra weight in my tummy got uncomfortable, I invested in the Gabriella Maternity Light Support Belt. Another fantastic one which a lot of professional runners use is ReCORE’s Fitsplint. A belt worked wonders in taking the pressure off so I could still log slow miles throughout my pregnancies. Also, this is common sense—but make sure you have good supportive shoes.
5. Manage morning sickness.
If you’re dealing with morning sickness and still trying to run—take heart. Our Mother Runners said sipping Gatorade on their runs helped calm their queasy stomachs. Dr. Cole Hosenfeld of Apple Healthcare recommends dropping your mileage by 10 percent to see if your symptoms ease.
Related: Best Foods to Eat Postpartum
6. Eat right and drink often.
Yes, you are eating for two, but you only need to eat about 350-450 more calories a day more than your usual in your second and third trimesters, says nutritionist Betsy Johnson. She recommends eating a mid-morning and late-afternoon snack, and every meal should include healthy fats, carbs, and protein. (And, take your prenatal vitamins!).
“During pregnancy and lactation, your fluid shifts will be higher. This is because your body is holding more fluids and your body creates more heat so the shifts are greater. Therefore, electrolytes will be helpful to restore higher fluid losses,” she explains.
- If you sweat a lot (>1 pound per hour), add a salty snack before or after your workout. Pickles, pretzels or saltines are great.
- Start with 16 oz fluids at least one hour before exercise and drink 4-6 oz every 15-30 min during the workout. You will need more if it’s warmer or less if it’s cooler.
- Prehydrate before longer runs by drinking extra fluids the night before and continue after the run.
- If you’re worried about having to make pit stops, go before your run and plan a route where there are places to go to the bathroom.
7. Find slower running buddies.
If you’re keeping your heart rate at 140 or below (or at a conversational pace), you may not be able to run with the same friends you ran before you became pregnant. Find people who will run at an easier pace.
Or, if you are running with the same people, run with them on their easy days and let them know your limits. Speak up if the pace gets too fast.
8. Take naps.
Your body is working overtime growing a human and chances are your sleep is interrupted by discomfort and having to pee several times a night. Heed those heavy eyes and try to lay down whenever you have the opportunity to rest.
9. Raid your partner’s closet.
This is kind of genius—if you don’t want to spend a lot of money on maternity running clothes, consider raiding your partner’s closet for workout shirts you can wear while your tummy is housing a human.
10. Have grace.
Your body is freaking amazing. It’s built to run and it’s built to have babies. It’s going to be changing and doing what it needs to bring a human into the world. Don’t stress about gaining weight or missing runs. It’s adapting to this major change and it will adapt again after you have your precious baby.
Related: How to Start Running Postpartum
If you want guidance with your training, including running while pregnant or postpartum, check out my run coaching services. Also, be sure to check out my free training plans: