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Amanda Pressner Kreuser

Prenatal Exercise: How Much Is Too Much?

Social media has shined a spotlight on moms-to-be doing intense workouts like surfing and SoulCycle. But where do we draw the line?

Lea-Ann Ellison, 35, never expected to find herself at the center of a social media firestorm. But when the Los Angeles–based mom of three logged on to her Facebook page one morning, she was stunned to find more than 5,000 comments on an image she had posted of herself lifting a barbell during her daily CrossFit workout. So why the backlash? Ellison was 32 weeks pregnant at the time — and the weight above her head looked almost as big as she was. “People wrote some very ignorant remarks, telling me that my choices were selfish and I was risking hurting my baby,” says Ellison. “They said I’d be to blame if anything happened to him.”

But Ellison isn’t alone in catching heat for her fitness decisions. A few years earlier, mom-to-be Amber Miller ran the Chicago Marathon at 39 weeks pregnant — and gave birth to her daughter just hours later. Internet naysayers questioned Miller’s judgment and why she did something that seemed so extreme and self-involved at a time when she should have been focusing on her child. More recently, Kristina Olivares, an Australian surfer, raised eyebrows for riding waves through all nine months of her pregnancy. While all three women delivered very healthy babies, the controversy continues over whether or not moms-to-be should keep doing high-intensity workouts right up until childbirth. Can certain rigorous exercise subject expectant women and their babies to unnecessary risks — or is it somehow actually good for us?

Experts weigh in

It seems that the expert consensus may fly in the face of what well-meaning moms, aunts and even friends have been telling you since you shared the happy news of your pregnancy. “As long as she consults with her doctor and gets clearance, there’s no reason that a healthy woman — one who is not deemed high risk — can’t continue the same type of workout she was doing prior to getting pregnant,” says Raul Artal, MD, editor for The American College of Obstetricians and Gynecologists’ (ACOG) Clinical Updates in Women’s Health Care.

Of course, not every type of activity is deemed safe. According to ACOG’s latest guidelines, you shouldn’t participate in contact sports like kickboxing and karate, or those activities in which you could inadvertently get hit with a ball, such as soccer or softball. You’ll also want to avoid the potentially hard falls you could take when skiing, snowboarding or horseback riding, and you should definitely skip scuba diving (it puts baby at risk for decompression sickness or even death).

Artal confirms that even the popular training regimens that may seem extreme to some, like long-distance running, cross-training and indoor cycling, are safe for pregnant women to continue — but only if they’ve already been doing them regularly pre-pregnancy and they’re under the supervision of their physician.

A far greater issue is that many expectant mothers stop being active altogether, which can lead to excessive  weight gain and gestational diabetes, both of which can negatively impact the well-being of the fetus, Artal says. “In fact, we strongly recommend that moms-to-be aim to get at least 30 minutes of physical activity five times per week.”

A myth that won’t quit

Somewhere along the way, you may have heard that exercise during pregnancy is only safe if you avoid letting your heart rate go above 140 beats per minute. So then how can super-active workouts like spinning, Zumba or circuit training actually be good for you?

Well, it turns out that number is old news. “The 140 beats-per-minute recommendation is outdated — and it’s long since been tossed out by the medical community,” says James Pivarnik, PhD, FACSM, professor of kinesiology and epidemiology at Michigan State University. And Artal, who was among the doctors who came up with the 140-beats-per-minute guideline a few decades ago, confirms that sentiment. “Newer research has since shown that our original theory was invalid,” he says.

New exercise guidelines

Doctors now agree that perceived exertion, a self-reported measurement of how hard you feel you’re working out, should be the benchmark used for when to slow down or stop. If you chart your exertion on a scale of 1 to 10 (where 1 means you’re barely moving and 10 is a red alert and you’re almost completely out of breath), you want to stay within the 6 to 7 range. Working out in that zone (rather than a 3 or a 4) can actually have positive effects on your pregnancy, according to research. To stay in a safe range, Pivarnik recommends making sure you can still hold a conversation during most of your workout (if not, slow down) and to stop immediately if you begin to feel weak, dizzy or in pain.

It’s also essential to keep yourself well hydrated and avoid becoming overheated. That means while a  prenatal yoga class is a good idea, a Bikram (hot) yoga class definitely isn’t. And when doing traditional yoga, you may have to modify your moves so you stay comfortable. If you’re exercising in a class setting, make sure the room you’re in has good airflow and you’re positioned near a door so you can make an easy exit if necessary.

Adjusting your routine

Even the most well-conditioned fitness buffs among us may need to make adjustments to our exercise routines to accommodate the changing demands on our bodies during pregnancy. These changes may include lifting lighter weights, pedaling more slowly during a spin class or running fewer miles at a reduced pace.

“You don’t have to stop doing your favorite workout,” says Pivarnik, “but you need to be particularly vigilant about listening to your body and not pushing yourself to do more than what feels comfortable.” Pivarnik explains that pregnant women can be at slightly higher risk for injury because their bodies are producing higher levels of relaxin, a hormone that loosens up your ligaments and joints. While relaxin makes your body better prepared for labor, its increase also means you’re more susceptible to rolling your ankles or over-stretching your joints.

“If you’re not sure how to best modify your movements,” don’t be afraid to ask your instructor to help you, says Jolie Walsh, a New York City–based SoulCycle instructor, who continued to teach and ride throughout both of her pregnancies.

Focusing on the positive

Even if you’re making all the right moves to keep you and baby safe as your belly grows, you may still encounter comments from others about your exercise regimen.

“There were a few people at my gym who didn’t agree with my exercise program,” says Tass Vorous, 36, who did classes like Zumba and Tabata throughout her pregnancy. “To deal with any negativity, I just focused on the support from the other expecting moms — we were almost like a tribe going through this together!”

The bottom line: Doctors agree it’s critical to remain active during your pregnancy — so long as you’ve come up with a plan with your ob-gyn and follow all her instructions for keeping you and baby safe. Sticking with the workout you love may be the best way to prepare your body (and baby’s!) for the marathon of  labor and delivery ahead. “After I got pregnant, my whole mind-set about working out changed,” recalls Ellison. “It wasn’t a competition anymore. It wasn’t about looking good anymore. Exercise was about staying strong and healthy so that I could be in great shape for one of the most important events of my life: helping my new baby come into the world.”

Plus, More from The Bump:

How to Fit Exercise Into Your Busy Schedule

Pregnancy Workout Plan

Walking Exercises for All Fitness Levels