background img

Exercise During Pregnancy: How Much is too Much?

Q. I am a pretty fit person (I run, I do Pilates, etc.) but in all of my pregnancies I have toned down my workouts while pregnant, in large part because running just isn’t comfortable.

But, I’ve noticed a lot of pregnant women continuing very rigorous exercise (boot-camp-style classes) throughout most of their pregnancy. What is the general thinking on this? Is it safe to continue with a high-intensity workout, or should women be toning it down? Is the risk to the unborn child or to the body of the woman carrying the child?

– Clara

Q. I’m hoping that in one of your future blogs you can address the topic of exercise. What is forbidden and what isn’t? How much exercise is too much?

I ask this because I am an avid runner. When I was pregnant with my first child, I continued to run up until my third trimester. Granted, my distances weren’t so great, and I was getting slower each time I ran, but still I continued. My doctor approved of my exercise. I ended up giving birth to a healthy baby boy. I would even go as far to say that maintaining an exercise routine during my pregnancy lessened the pain of labor and childbirth.

That being said, I got sooooo many dirty looks on my runs!

– Jennifer

A. I can’t say I relate to Clara and Jennifer — I spent my pregnancy mostly focused on whether I really HAD to walk on the treadmill for 30 minutes a day or could instead just vegetate in front of reality TV. But I did look into the issue of intense exercise, just in case I had a sudden burst of energy. (I never did.)

The concern about exercise comes, at least in large part, from a few studies that show that women who do a lot of physical labor at their jobs have more pregnancy complications (preterm birth, for example) than women who don’t. One example is a study that shows that women who stand for more than six hours a day at their job are about 1.25 times as likely to have a preterm delivery as those who do not. The issue with this study is that women who have jobs that require them to stand a lot also tend to be different in other ways (less educated, for example), which also relate to preterm birth.

Better is to look at studies of exercise that are randomized, meaning that half of the women in the study are randomly selected for exercise encouragement. Studies like this generally consider what happens when you encourage women to do 30 or so minutes of aerobic exercise three to five times a week — basically, about what we are all trying to fit in.

The findings suggest that there is little impact: no change in preterm birth rates, gestational age, frequency of cesarean sections, or fetal growth. There is no evidence of a difference in baby Apgar scores or in the length of labor. The studies also don’t find any negative impacts on the mom.

This suggests that if you’re engaging in 30 minutes of standard aerobic exercise in pregnancy, that’s fine to continue. However, there is some evidence that exercising really hard during pregnancy could (very temporarily, during the period of exercise) compromise blood flow to the baby. In one study of six Olympic-level athletes, researchers found that when women exercised so hard that they pushed their heart rate to more than 90 percent of their maximum heart rate, there was a decrease in the fetal heart rate below what is considered normal. This was temporary — when the women stopped the exercise the heart rate returned to normal. However, there is a concern that repeated fetal distress — if exercise like this occurs every day during a pregnancy — could have negative consequences.

So how to know when you are exercising too hard? Your maximum heart rate is around 220 minus your age. If you’re pregnant at 30, this is 190 beats per minute. The evidence from elite athletes therefore suggests you should stay under 90 percent of that, or about 170 beats per minute. If you think you may be coming close to this, by all means get a heart monitor and try it on a few runs. If you find you’re not coming close, you can start leaving it at home.

-Emily Oster, Slate

For the social athlete: Win an Apera Sports Bag worth $131


Yeah, you need another bag.

Simple, sleek and uncomplicated, Apera’s new PureSport Sling Tote is my new go-to bag for the car with the kiddos. I know, it’s supposed to be a gym bag for the “social athlete” but it rocks for the car and children. With ample space for clothes, shoes, water bottles and easy-to-reach pockets for snacks, this bag stores all of my random necessities in an accessible location for the car.

What’s even better, the entire bag is antimicrobial, waterproof and comes with a small washable insert, extremely important for car trips when a rogue coffee spill might encounter the bag or a child’s juice cup with no lid. These things happen.

The Bar Method – Try it for FREE!

When I told my husband that I’d been invited to try a new exercise routine at a new studio in Boulder, he was supportive. “It’s called The Bar Method, and I signed up for a Saturday morning class…so I’ll need you to watch Claire,” I said.

He got a funny look on his face and started laughing.

“Isn’t it a little early to start drinking?” he asked.

His question made me laugh out loud. “Oh! No! It’s not a BAR. It’s the bar METHOD…like with a bar ballet dancers use,” I said.

He asked me what all was involved, besides using heavier Margarita glasses, and I laughed again. I told him I had no idea, but that I was excited to find out.

Back in March, I’d started a new exercise routine called The 30 Day Shred with Jillian Michaels and had great results. (You can click here to read all about my adventures in going from an exercise-less slug to someone who actually discovered abs under her flab.) I’ve kept up the routine, but I’m always on the lookout to find something new to add to the mix. When I was offered a chance to try this class for free, I jumped at it.

I looked online at the different class offerings, and there were a variety of dates and times available. My challenge was finding a time when my husband could watch Claire (our 3-year old) long enough for me to make my escape. I found a class that would work in both our schedules, and it was really easy to sign up online. I couldn’t wait to get up to Boulder to try it out. Saturday rolled around, and I was ready to go!

I put on my appropriate clothing.
The challenge for those of us who work out in the privacy of our own basements is finding an outfit that won’t scare the other members in the class. Always one to plan all the logistics before I go, I was happy to see they had a FAQ page on the website, which told me what to wear to the class: Be sure to wear socks and pants that cover your knees. Luckily, I had an outfit that worked!

The studio was super-easy to find.
It is located in Boulder at 2425 Canyon Blvd at Folsom in the WaterStreet Plaza, and there was plenty of free parking.

It was easy to get signed in, and Leslie, the instructor, made me feel welcome.
I immediately felt at ease with her. The Bar Method provides lockers (and a cute little board for hanging the provided locker-keys in the room), so picked my favorite number. I stored my car keys and shoes, hung my little key on the wall, and I was all set.

The studio was new and inviting.
The room was modern, clean and smelled fresh and new. There were mirrors on the front and side of the room. The floor was carpeted and had a spongy feel to it.

Right on time, we got started.
At first, working out in front of two sets of mirrors was daunting, but I quickly got over that. It was really cool to be able to see my form and make corrections. (Normally, I have to ask Claire if my back is straight, but I have a feeling she always says, “Yes.”) Leslie was warm, welcoming, funny, and a great instructor. There were about a dozen of us in the class, and Leslie took time to come around and make little adjustments to our form, and the personal attention was great!

The actual workout was incredible.
Throughout the hour-long class, I did exercises I’ve become familiar with in other routines, and it was good to see that I’ve been doing them correctly. I even discovered that I’ve been doing some of my exercises incorrectly, so I’ve learned the proper way, now. Then, I did things I’ve never done before, and I used muscles I never knew I had.

Even as a newbie, I was able to keep up with the other people in the class.
There were modifications for some of the exercises. I took advantage of some of them, but I was able to do most of the more advanced movements. A couple of times I was confused about what we were supposed to do, but it didn’t take long to figure it out and follow along. The benefit to doing these exercises in a class setting with a real-live instructor was amazing and something I’d never experienced.

I didn’t stick out like a sort-thumb…or like someone who’d never used a ballet bar before.
Yes, it’s true. I’ve never used a ballet bar. But, you know what? I fit right in with the people who had obviously done these things before. At one point, I did have to stifle a laugh when one of my feet did not want to go the way Leslie told me to make it go, especially when my other leg was all the up on the bar, but we got it figured out. And, not once did I fall off the bar. (Wow, I have to be careful not to take that out of context, or my husband would be laughing at me again!)

They are not kidding when they say this is “the most targeted body-shaping workout.”
I left that class feeling a wonderful mixture of exhaustion and exhilaration. I won’t lie: The next day was a bit stiff and sore around these parts. Which parts? All my parts, including parts I didn’t even know I had. But you know what? It was so worth it!

Whenever I have a great workout like that, it really gets my brain juices flowing.
I tell ya…if I had a part-time nanny and a bigger budget, I could take over the world. Ever since that class, I’ve been mentally calculating a way to juggle our schedules and finances so that I can get into more of these classes!

Speaking of which, I’m happy to announce a special that the Boulder studio is running: You can receive your first class FREE! You will then be eligible for a $100 30-Day unlimited New Client special, and they’ll throw in a Bar Method gift bag to any Mile High Mama who signs up!

You really need to try out The Bar Method! If you do, tell them we sent you!