Carrie Cole ran her fastest half marathon while pregnant.
"It was really hard, but really strong," remembers the 32-year-old in Wilmette, Illinois, who now works for a company that organizes races. She didn't find out until after the race that she had a baby on the way.
Cole also ran a half marathon while eight weeks pregnant – with twins. That time, a personal record was not in the cards. "It was very difficult, and I had to walk parts of it," says Cole, whose twins are now 2 years old. Though she stopped running for the duration of her pregnancy after that race, she says the experiences taught her "it's absolutely possible to run safely with a pregnancy – or waddle by the end."
Experts increasingly have the same perspective, says Dr. Stephanie Romero, an assistant professor of obstetrics and gynecology and maternal fetal medicine at the University of South Florida Morsani College of Medicine. "People used to think of pregnancy as a disease state by itself and that pregnant women were fragile in some way, but no, that's not the case at all," she says. Now, the American College of Obstetricians and Gynecologists recommends pregnant women without obstetric or medical complications exercise at least 30 minutes a day most – if not all – days a week, just like the rest of the population. Regular runners, the organization says, can keep running, though they might have to modify their routines. "We're seeing more and more data about how beneficial exercise truly is in pregnancy," Romero says.
For example, staying active while pregnant helps prevent gestational diabetes, hypertensive disorders,preterm deliveries, lengthy deliveries and high birth weight babies, says Jim Pivarnik, a kinesiology and epidemiology professor at Michigan State University, where he directs the Center for Physical Activity and Health and studies how exercise affects pregnant women.
"The number of advantages for any [pregnant] woman, whether she's hardcore or somebody who just wants to maintain her activity, are many," Pivarnik says.
For Cole, who typically ran three or four times each week before becoming pregnant, continuing to run helped her maintain peace of mind. "There are so many things you can worry about [when pregnant]," she says. "Running is my way to make all the worries stop and just focus on one thing. "
Whether you run to clear your head, compete in races or just stay in shape, here's how to do it safely and as comfortably as possible:
1. Be honest.
As early in your pregnancy as possible, tell your provider your plans for physical activity. Chances are, they'll cheer you on. "I never tell a patient 'don't exercise,'" says Romero, who adds that pregnant patients ask her weekly if they can run 5Ks. "It's a great thing to exercise."
However, certain sports that raise your risk of falling, such as horseback riding and skiing, or getting hit in the stomach, such as soccer and ice hockey, are ill-advised, according to ACOG. Women with certain conditions such as severe anemia, poorly controlled Type 1 diabetes and pregnancy-induced hypertension may not be cleared for aerobic activity, ACOG says.
2. Don't try new distances.
If the most you've run is a 5K, pregnancy is not the time to sign up for your first 10K, Romero says. A good rule of thumb: "Don't do anything new with your pregnant body that you've not attempted with your non-pregnant body," she says.
Even regular runners may find that lower-impact activities, such as the elliptical or swimming, can be more comfortable when pregnant. For example, women who are prone to back pain and other injuries, as well as women with a big baby bump but not a lot of weight elsewhere, might find running while pregnant isn't for them, Pivarnik says. Other women may discover they enjoy running during one pregnancy but not during another, says Jen Hoehl, a personal trainer in New York City. "Every pregnancy is different," she says.
No matter how you stay active, keep your focus on your health and growing family – not a shiny new race medal, recommends Hoehl, who mostly walked and weight-trained while pregnant with her first child born in May. "If you want to run a 5K, 10K, even a 15K with your girlfriends, that's awesome," she says. "Just don't try to be the runner that ran the marathon at nine months just because you were signed up for it."
3. Know the warning signs.
After Cole's half marathon with twins, she noticed some spotting. Because her first pregnancy had ended in miscarriage (unrelated to running, her doctor assured), "I was terrified that I had done something terrible," she says. Fortunately, she hadn't, but when she told her doctor about her race, he said, "Congratulations! Now don't do it again," Cole remembers. She listened.
Vaginal bleeding, dizziness, headaches and chest pain while exercising are all signs to stop and talk to your doctor before taking another stride, ACOG advises. Some discomfort during pregnancy – while running or not – is normal, but "don't fight through it if it's painful," Pivarnik says. While it's safe to run up to the minute you go into labor, stop earlier if you don't have the energy or experience joint pain, Romero advises. "This is not a time to be tough and push through it," she says.
After Cole's half marathon, her doctor set a limit on her heart rate during exercise and prescribed partial bed rest at 25 weeks. While her history of miscarriage and twin pregnancy warranted the cautious approach, taking a running hiatus wasn't easy. "I have never been so angry at other runners – I was so jealous," says Cole, who would watch them pass by her window. "But I put a price on that … it wasn't worth it."
4. Watch your form.
Particularly after your first trimester, your center of gravity will be off, thanks to your expanding tummy. That means you have to take extra precautions, like running only on smooth surfaces (no trail runs, that is), to stay upright. "Don't take your balance for granted," Romero says.
Carrying a child also means an increase in the hormone progesterone, which helps loosen the hip joints for delivery. But since the hormone effects other ligaments and joints too, it can make you more prone to injury, Romero says. "It's not a good time to get lazy about form." Hoehl recommends focusing on hip-strengthening exercises like hip raises to reduce your likelihood of a spill on the road.
5. Keep cool.
Decades ago, pregnant women were advised to keep their body temperatures from climbing too high, but research on the consequences is scarce, ACOG concludes. Not to mention that few women run with thermometers in their mouths, Pivarnik says. Feeling more hot and sweaty than usual is "a physiological response to help remove the heat from the core, so that's a good thing that you feel that hot," he says.
Still, it's a good idea to do what you can to keep cool when running during pregnancy. Pivarnik recommends avoiding outdoor runs during hot summer days and using a fan if you're hitting the treadmill.
6. Prepare for incontinence.
Cole's half marathon with twins was the first race she ever had to stop to pee. Other women may not even be able to stop before some urine comes out, Romero says. "Your sphincter tone goes down, and the pounding of your feet on the pavement will make it much more likely that you lose continence," she says.
To combat it, try wearing a tampon while running. "That provides enough internal support that you might leak a little bit, but it would definitely be a lot less," Romero says.
What not to do? Skimp on your water and sports drink intake. "As much as it's important for any athlete to stay hydrated, it's more important for a pregnant athlete to be hydrated because they circulate more blood faster than the typical person," Romero says. "They need to be able to retain that volume and replace what they're sweating off."
7. Gear up.
If a bouncing belly is making running too uncomfortable, consider wearing a maternity support belt. Some of Pivarnik's colleagues, whom he ran with while they were pregnant, used the belts and found them to be "better than nothing," he says.
Romero also recommends investing in compression shorts or pants, which can help make swollen legs more comfortable. And as for those puffy feet? They may be just the excuse for some new running shoes – since you may need to go up a size.
8. Keep it up.
As soon as her doctor cleared her to run after giving birth to her twins, Cole started running again. She now mostly sticks to shorter distances like 5Ks that she and her husband can run together – their stroller and toddlers in tow.
Being able to pick up your fitness routine where you left off is just another advantage of keeping active while pregnant, Pivarnik says. The other? Making fitness a family affair. Later in life, Hoehl says, "you can run together."
8 Tips For Running Safely and Comfortably (Enough) While Pregnant was originally published on U.S. News & World Report.
Also on HuffPost: