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Running Pregnant

Last year, I ran the Boston Marathon, cycled most of the 150 miles from Duluth, Minn., to St. Paul and canoed 140 miles down a creek in Alaska — all while pregnant with my first child. While I strived to maintain my fitness, I also spent countless hours worrying about possible side effects.

Despite current research that links healthy exercise to a healthy baby, confusion and misinformation persist. A nurse told me to stop running when I was a few weeks pregnant. I heard that I shouldn’t cycle outside, shouldn’t run for more than 30 minutes, shouldn’t lift more than 30 pounds. My heart skipped a few beats when I read – after my yoga class – that the cat-and-cow posture should be avoided at all costs.

But working out felt right, and I had my doctor’s OK. Nine months later, I gave birth to my healthy son: Wes weighed 7 pounds, 15 ounces. But during the course of my pregnancy, I bombarded my doctor with questions. She sent me studies, and I Googled everything from “hypoxic breathing during swimming” to “hiking at high elevations.” Too often, I found conflicting advice – or none at all.

“There’s been a lot of fear, and that’s really been a disservice,” says Catherine Cram, MS, an exercise physiologist and coauthor with Tere Stouffer Drenth of Fit Pregnancy for Dummies (Wiley Publishing, 2004). “Exercise in noncomplicated pregnancies is beneficial for both mom and baby.”

Whether you currently work out for the sake of your health, your appearance, your athletic performance or some combination thereof, there’s a very good chance that pregnancy will change your fitness routine. But how? And how much? And why, exactly?

If you’re a mom-to-be, you’re probably hearing numerous theories about what is and is not safe or healthy, leaving you with the frustrating task of sorting it out for yourself. Faced with this thick fog of doubt, many women elect to simply play it safe and sit it out for several months, dropping or dialing back their fitness regimens to nearly nonexistent.

Yet the most current research indicates the healthiest route is to do just the opposite. Forward-thinking experts say pregnancy is actually a good (and motivating) time for sedentary women to begin an exercise program. “Your body is designed to handle being pregnant, and it does it very, very well,” Cram says. “And by exercising, you’re preparing your body to hit the ground running when you do have your baby.”

In an effort to further separate pregnancy fitness myths from reality, I talked to a few experts who have spent years studying active moms-to-be. Here’s everything I wish I would have known while trying to make an informed decision about working out while pregnant.

Debunking Myths and Misconceptions

In the 1980s, James Clapp III, MD, set out to study what he assumed would be the health risks associated with exercising during pregnancy. Today, Clapp is still studying the issue – and extolling the benefits of fitness for moms-to-be. His work debunks most of the myths that have scared pregnant women away from the gym. Among the most common misconceptions:

  • “Exercise can cause infertility, low birth weight, congenital abnormalities and preterm labor.”
  • “Running and other forms of weight-bearing exercise can cause miscarriage.”
  • “Some forms of exercise can cause the fetus to get tangled up in the umbilical cord.”Accompanying such dire warnings came a long list of seemingly arbitrary pieces of advice, including:
  • “Don’t let your heart rate exceed 140 beats per minute.”
  • “Don’t exercise for more than 15 minutes at a time.”
  • “Don’t start a new exercise regimen once you become pregnant.”

These myths and misconceptions, Clapp says, are unfounded. Although the American College of Obstetricians and Gynecologists (ACOG) updated its guidelines in 2002, lifting most restrictions on exercise during pregnancy (including keeping your heart rate under 140), many healthcare providers still aren’t aware of the revisions.

“Pregnant women were traditionally told ‘don’t move’ and ‘eat for two,'” says Raul Artal, MD, chairman of the Department of Obstetrics, Gynecology and Women’s Health at the St. Louis University School of Medicine. That advice, says Artal, who helped draft the ACOG recommendations, turned out to be bunk.

Mom Knows Best

The current pregnancy fitness guidelines differ only slightly from exercise recommendations for other healthy adults. But because those general-public suggestions are quite vague, the task of deciding what’s OK and what’s not still frequently falls to the pregnant woman herself.

That’s not necessarily a bad thing, Cram says: “I like to see women trusting their own bodies, and that’s what I generally advise them to do. There’s no reason to let everyone around you make you feel tentative about this really wonderful experience.”

Expectant moms who hunger for more specific information may wish to turn to the Society of Obstetricians and Gynaecologists of Canada (SOGC) and the Canadian Society for Exercise Physiology (CSEP). Those organizations created fitness guidelines that have also been endorsed by the American College of Sports Medicine.

The guidelines, released in 2003 and available for download at, provide questionnaires to help pregnant women and their caregivers determine what’s appropriate for individual women. There’s also a list of resources and details on goal setting and intensity.

But the most important guidelines a mom-to-be should follow, Cram says, are her own instincts and common sense. “A mom knows better than anyone else how she feels,” she says. “We’re empowering women to say, ‘Something’s not right,’ or ‘I feel fine; there’s no reason I shouldn’t be able to do this.'”

When Andrea Winkler of Minneapolis was pregnant with her son, Marcus, she wanted to keep up her active lifestyle, and with a background in health education, she knew it made sense to do so. She talked with her doctor, did some research on her own and even consulted exercise-physiologist colleagues. Ultimately, she decided to keep up with all her fitness favorites, including weightlifting, yoga, riding her bike to work – even teaching indoor group-cycling classes.

“Sticking with my exercise routine kept me feeling really good about myself during pregnancy,” Winkler says. “It was very important to me not to just let everything go.” Staying in good shape also helped her with post-delivery recovery. Within days of giving birth via cesarean section, Winkler was taking hourlong walks with her son – not advisable for everyone, but well within her comfort zone.

Accomplished athletes who are already in tune with their bodies may actually have an advantage when it comes to making intuitive adjustments during pregnancy, says 38-year-old, two-time Ironman world champion Lori Bowden. “I think we as athletes have the benefit of being used to listening to our bodies,” says Bowden, whose first baby is due this month. “Your head thinks one thing, but your body quickly reminds you that you can’t go at the same pace or intensity. My calves are kind of achy while I run, and it takes a long time to warm up. But I feel happy just to be out, so I don’t mind going slower or shorter.”

Cutting back for Bowden meant, at five months pregnant, “only” swimming 90 minutes four or five times per week, running for up to an hour three to five times per week and cycling a couple of hours three times per week. But even moms-to-be with far less ambitious athletic tendencies stand to benefit from staying in shape.

Banishing Doubts

No matter how in tune you are with your body, it’s normal to wonder how anything and everything you do during pregnancy might affect you – and the little kiddo in progress. Understanding the benefits of exercise for both mom and baby can alleviate some of the potential fear and guilt caused by uncertainty.

Clapp’s studies, outlined in his book Exercising Through Your Pregnancy (Addicus Books, 2002), showed that women who exercised throughout their pregnancies gained less excess body fat and had shorter and easier deliveries as well as quicker recoveries. During labor, these same women were:

  • 35 percent less likely to need pain relief
  • 75 percent less likely to suffer maternal exhaustion
  • 50 percent less likely to need induced labor or to require Pitocin (synthetic oxytocin)
  • 50 percent less likely to need intervention because of abnormalities in the fetal heart rate
  • 55 percent less likely to need an episiotomy
  • 75 percent less likely to need forceps or a cesarean section

The studies also showed that women who exercised and gave birth vaginally were, on average, in labor only two-thirds as long as nonexercising women.

Clapp discovered that the placentas of fit moms tend to function better, creating a better blood flow between mother and fetus. Exercising also increases blood volume in moms, preventing varicose veins and swelling. The baby’s heart rate and other clinical data show that babies of fit mothers better tolerate the stresses of late pregnancy, labor and delivery. And benefits for those babies seem to extend long past birth: By age 5, they still show better body composition (and even score higher on general intelligence and oral language tests) than the offspring of the women who didn’t exercise during pregnancy.

The question is not whether a pregnant woman should exercise, but how she should exercise.

Exercising moms-to-be may also have a better chance of avoiding many of the diseases and complications associated with pregnancy, says Larry Wolfe, PhD, an exercise physiologist at Queen’s University in Canada who has also conducted studies on exercising during pregnancy. He found that varicose veins, deep vein thrombosis (a blood clot in the veins of the legs, pelvis or arms), low back pain, excessive weight gain, problems with body image and poor psychological adjustment to pregnancy are all alleviated by staying fit.

“Perhaps we should not be asking, ‘What are the risks of activity?’ but ‘What are the risks of being inactive?'” Wolfe says. Indeed, neither Wolfe’s nor Clapp’s research has found any short- or long-term problems associated with exercising during pregnancy.

General Guidelines

The question, then, is not whether a pregnant woman should exercise, but how she should exercise. Before you hit the pavement or the pool, it’s important to understand a few basics. It’s doubly important for moms-in-training to heed their bodies’ needs throughout the day:

  1. Fuel up. Eat enough to satiate hunger, Clapp says – preferably in small, frequent meals balanced with proteins, complex carbohydrates and healthy fats, and preferably from whole-food sources.
  2. Stay hydrated. Drink enough to keep your urine relatively clear (that’ll require approximately 91 ounces a day).
  3. Be gentle with yourself. Expect to ease up here and there. Pregnancy, after all, will cause more dramatic changes in your body in a short period of time than anything else in your life. Your body is also putting a lot of energy and resources into making another body – not a trifling effort!
  4. Rest as much as possible. Clapp suggests spending an extra hour at leisure for each hour you work out (in addition to your regular rest), and avoiding exercising to the point that you feel stressed out about it.
  5. Adjust your athletic expectations. “Slowing down is very hard when you’re an intense exerciser,” Winkler says. “When you’re used to exercising at a certain level and you have to slow down a little, it brings you more in touch with other areas. I found that I naturally focused more on work and family; it provided some balance in my life. I learned how to relax and slow down and be OK with it.” Triathlete Bowden has had a similar experience enjoying her fitness downtime. “Now that I’m pregnant,” she says, “I do more of my training with friends. Before, I needed to focus on such intense training that I couldn’t slow down enough to enjoy working out with other people.”

Regardless of your activity or fitness proficiency, it’s important to monitor the intensity of your exertion. Historically, this has been one of the most confusing areas of pregnancy fitness programs. Years ago, the popular thinking was that a pregnant woman’s heart rate should never exceed 140 beats per minute (because of baseless fears about raising fetal temperature). But using that standard, many women wouldn’t be able to do much more than get out of bed. And because pregnancy alters a woman’s heart rate, relying on traditional heart-rate charts can be deceiving.

A better option is to use a modified chart designed especially for pregnant women. (Wolfe’s lab developed an adjusted chart that’s available online at under “screening forms.”) But the easiest – and some experts say most accurate – way to measure your intensity doesn’t involve finding your pulse. Perceived exertion based on the Borg Rating of Perceived Exertion Scale (search for “Borg rating” at is a simple, effective tool that helps you gauge your level of effort, Cram says.

In lieu of more studies to ascertain the safety of working out at very high intensity levels, pregnant women are encouraged by experts like Cram, Clapp and Wolfe to keep their hardest workouts in the “comfortably hard” range, which generally means you can carry on choppy conversation while working out.

Physically active women and their fetuses adapt well to short bouts of strenuous exercise, suggests a new review written by Wolfe and his colleagues. But the safety of sustained, vigorous training has not yet been verified. Since the most common purpose of exercising during pregnancy is to maintain fitness and prepare for childbirth, Wolfe notes, there’s not much call for scientific exploration into the safety of high-intensity training.

Plus, he points out, even conventional fitness programs usually call for only small amounts of extremely intense exercise. Performance athletes who normally spend more time working out near their anaerobic threshold should ask their healthcare providers for guidance on appropriate levels of exertion and competition. You should also seek counsel about participating in contact sports (generally not recommended).

Obviously, all these recommendations still leave a fair bit up to the discretion of the individual mother-to-be. In situations where you’re unsure whether to speed up or ease up, Cram encourages you to think about the risk-benefit ratio. “I knew a woman who wanted to run a marathon at 32 weeks in the dead of summer,” she says. “Was it worth the risk? I told her it wasn’t. You want to be reasonably cautious. But you don’t need to treat yourself like a china doll, either.”

Every expert’s advice, however, contains one caveat: If any preexisting conditions put you at greater risk, or if any health issues or complications develop during the pregnancy, you should consult your physician before beginning or continuing an exercise program. Even if you’re healthy, be prepared to adjust your workout habits from trimester to trimester.

How To Workout During Your First Trimester

When Beth Birkholz, a fit mom from Atlanta, was pregnant with her first child, her weight climbed and her blood pressure skyrocketed, eventually causing complications that led to a cesarean section. Now pregnant with her second child, she’s determined to keep exercising to avoid more complications.

Striving for a healthy pregnancy and vaginal delivery, she lost 45 pounds before getting pregnant and even ran a marathon a few days before finding out she was expecting. She set new fitness goals for her pregnancy: running at least three times a week until it gets uncomfortable, then walking or doing aerobics three times a week.

“There can be no comparison between this pregnancy and the last one,” she says. “I’ve felt better, slept better, I’m eating better – and when I run, I feel like my more comfortable, unpregnant self for a little while.”

In the first trimester, a pregnant woman’s body is busy adjusting to its pregnant state, which causes all sorts of discomfort and, potentially, decreased athletic capacity. During exercise, you may experience a high heart rate, dizziness and shortness of breath. You also may be exhausted or constantly nauseated. Those conditions will probably limit you more than any exercise restrictions – although many women, like Birkholz, find that exercise lessens nausea and makes them feel more energetic. In addition to your regular exercise routine, adjusted to pregnancy-appropriate intensity levels, you’ll benefit from exercises like pregnancy-safe abdominal exercises. (See “Abs? Absolutely!” below.)

If you don’t already actively monitor your well-being, start now. Clapp suggests keeping track of how you’re feeling and how much weight you’re gaining.

How To Workout During Your Second Trimester

As Andrea Winkler’s pregnancy progressed, she gradually modified her fitness routine. She cut short her runs, sought out the coolest spot in the room during her yoga classes and moved to an inclined bench for abdominal workouts.

During the second trimester, your body is adapting to a host of changes: It’s producing hormones (specifically, one called relaxin) at an astonishing rate, making you more susceptible to sprains and joint injuries. Your blood volume increases. Your center of gravity is shifting, which throws off your sense of balance. The weight of your uterus begins to press on your vena cava (the vein that transports blood from your lower body to the heart) when you’re lying on your back, causing lightheadedness in some women.

Fortunately, there are many modification techniques to make you comfortable, Cram says. Some of the most common:

  • Runners can support their expanding bellies with a maternity support belt or switch to aqua jogging in the pool.
  • Novice cyclists can move to a stationary bike or Spinning class when they feel off balance. Moving the handlebars up will accommodate your belly. A recumbent bike, especially a stationary one, is another great option, especially if you’ve used one before. Or consider an elliptical trainer.
  • Yoga practitioners can roll to their side during relaxation postures and should use caution with jumps and inverted poses (if you’ve never done them before, now is not the time to learn). Most experts recommend avoiding yoga disciplines that require a hot room, such as Bikram.
  • Because the concentration of relaxin in your system increases your joint’s vulnerability to injury, it’s wise to avoid bouncing stretches and ballistic movements.
  • Aerobics buffs can decrease the intensity by lowering the platform in a step class or opting for the low-impact version of a workout.

That said, the second trimester can also be an ideal time to ramp up your workouts. Many women feel less nauseated and more energetic during this period. So monitor your well-being: If you’re feeling good and gaining weight normally, continue building your exercise routine. In addition, Clapp suggests making sure the baby moves two or three times in the first 30 minutes after exercise. Lack of motion can be a sign of physiological stress, so if movements cease, assess how your body feels, and if concerned, see your healthcare provider.

Expert advice on duration and frequency of exercise varies, but if you’re accustomed to a high level of training, you should be able to work out up to an hour, five or six days a week, as long as you have your doctor’s approval and don’t develop any problems with your health or your pregnancy, Cram says.

How To Workout During Your Third Trimester

At nine months pregnant, Winkler had stopped commuting to work on her bike, but she was still teaching indoor group-cycling classes.

“People would say, ‘Is she nuts?'” Winkler remembers. “But I’d say, ‘Don’t be deceived by a pregnant woman. I’ll work you guys to the bone!’ Toward the end of my pregnancy, I couldn’t make it up the hill or sprint as fast, so I backed off and watched my class participants enjoy their ride home.”

Women who continue to perform weight-bearing endurance exercise throughout pregnancy often go into labor slightly earlier: on average, five to seven days, according to Clapp’s studies. If that’s not enough motivation, consider that the third trimester is a crucial time to stay active in order to maximize the postpregnancy benefits of working out (including losing weight and feeling more energetic and less depressed). The babies who experienced the most benefits were born to mothers who maintained weight-bearing activity in the third trimester.

Be confident with your exercise routine, but do be aware of your body and its signals. In addition to the warning signals in the first two trimesters (abnormal breathing, dizziness, swelling in your legs, significant vaginal bleeding, and severe or unrelenting headaches), women with any of the following symptoms or conditions should see their healthcare provider before continuing exercise:

  • Vaginal bleeding originating from the womb. (Have your healthcare provider evaluate any bleeding to pinpoint the source.)
  • Contractions that persist for more than 20 to 30 minutes after exercise
  • Ruptured membranes (“water” breakage)
  • Evidence that the uterus or womb is not structurally normal, usually from a previous pregnancy. (Your doctor would catch this during your regular checkups.)
  • Carrying multiples
  • History of premature labor

Fit to Deliver

So what’s your fit-pregnancy prescription? If you’re fit, stay fit. If you’re not fit but are otherwise healthy, make exercise a priority during pregnancy. It will probably help you and your baby in more ways than studies yet show.

There’s a sound body of evidence that working out while pregnant is good for you and your baby. And there’s virtually no evidence that even the most intense fitness fanatics (professional athletes) are likely to experience complications from maintaining a high level of fitness during pregnancy.

For me, both the physical and psychological benefits of regular exercise were immeasurable. Although I stopped racing when I discovered I was pregnant a few days after finishing the Boston Marathon, I continued running, swimming and indoor cycling. And in the weeks after giving birth, a half hour of walking or light jogging rejuvenated me for the rest of the day.

When Wes was 2 1/2 months old, I ran my first postpartum 10K. He watched from his stroller, and my husband cheered me on. As I crossed the finish line, I noted that my time was within five minutes of my best – and I still had enough energy to sprint an extra 100 yards to kiss my son.

Abs? Absolutely!

While it’s true that pregnancy is a great excuse to skip sit-ups, it’s no reason to forgo all abdominal exercises. In fact, maintaining a strong core helps prevent back problems and speeds postpartum recovery.

During pregnancy, your center of gravity changes. That, in turn, causes the lower back to curve in more, says exercise physiologist Catherine Cram, MS. “At the same time, the belly muscles, which normally would provide support for the spine, are weakened by the separation of the rectus abdominus muscles,” she says. “These changes put the lumbar spine at risk and can lead to back pain and disc problems.”

The muscle separation, known as diastasis recti, is a normal response to an expanding abdomen, Cram notes. It only becomes a problem when the separation is so wide that the muscles are unable to provide any support. Keeping your midsection strong by following these guidelines will help the muscles recover more effectively:

First, don’t do sit-ups. “Most sit-up type exercises do relatively little to help increase abdominal strength – and they put the low back and belly muscles at stress,” Cram says. Instead, she says, in addition to pregnancy-specific exercises like Kegels and pelvic tilts, incorporate these two very safe and effective exercises, as described in Fit Pregnancy for Dummies:

  • Sitting on a workout ball, place a resistance band under one foot. Securely grasp the band in each hand until you feel some tension in the band. Exhale, and lean back. Keep your back straight and extend back from the hips. When you feel your abs contracting, hold for five seconds.
  • Lying on your back with your knees bent and your stomach contracted, slide one leg forward until it reaches the floor. Slide it back and repeat. When you’ve mastered that, start in the same position – but this time, raise your knee toward your chest before straightening your leg and lowering it until it’s 2 or 3 inches off the floor. Repeat with the opposite leg.

This article originally appeared as “Fit for 2.”

Sheila Mulrooney Eldred

Sheila Mulrooney Eldred is a Minneapolis-based freelance writer.

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