Many of you who have been lifting for a while have probably seen an account of a very pregnant women in the gym lifting a heavy barbell (gasp!). I’m sure most people have some sort of positive or negative feeling about this, but it is true that lifting weights during a normal pregnancy is perfectly safe. However, there are some things a mother-to-be needs to be concerned with. You’ve probably gotten various warnings from your family, random strangers, or your overly concerned coworker, Susan, so let’s go ahead and sort out the myths from the real safety concerns.
The first thing I want do before you lose interest and decide to just casually skim the rest of this article is talk about two things that you should actually care about.
Letting your core body temperature get above 102 degrees Fahrenheit is not good for your babe. Use caution when training in super hot temperatures during summer months. If you’re pregnant, probably don’t do Prowler pushes outside, in Texas, in July... in the afternoon. I don’t know what sane person would do that anyway, so actually, just don’t do that ever.
Once the baby reaches a certain size, mom is cautioned against lying flat on her back (supine) for extended periods of time due to the risk of aortocaval compression syndrome, or in other words, compression of the central vessels by the uterus when lying supine. This decreases venous return to the heart, which decreases cardiac output, and can result in loss of consciousness or even fetal death if left unresolved. Symptoms include dizziness, nausea, sweating, increased heart rate, and pallor. The symptoms resolve when the mother changes positions, and there are no long term consequences for her or the baby. If you are able to lie supine for a few minutes at a time without symptoms, this is usually fine. If you start to feel any of the symptoms listed above, it’s not fine, and you should roll over and/or sit up.
So now that we got the important stuff out of the way I would like to go ahead and debunk some myths that some well-meaning but perhaps misguided person might have told you, like, “oh, be careful! You don’t want to raise your arms over your head like that or you’ll strangle the baby!” (Um, thanks Susan? But I don’t think that’s actually a thing.) The first is about your heart rate. Many years ago, when recommendations were needlessly cautious, pregnant women weren’t supposed to let their heart rate exceed 140bpm. Today, a heart rate limitation is generally not imposed. That’s right, Susan. I know what I’m doing.
One specific reason doctors may not want their clients lifting heavy weights is because of the “risks” associated with the Valsalva maneuver. Most people who lift heavy barbells know that the Valsalva maneuver is not only not dangerous, but is also a protective mechanism against spinal injury. There are no official recommendations from the ACOG against the use of the Valsalva maneuver while pregnant. Regardless, the concern from doctors who don’t lift is that the Valsalva maneuver will temporarily decrease oxygen to the fetus, which could be harmful. I, on the other hand, would argue that a) the benefits of protection against injury far outweigh any perceived risks from holding one’s breath, and b) you’re probably only holding it for 3-5 seconds, tops. We’ll talk a bit more in detail about programming in future articles, but we don’t recommend max effort training which could lead to the Valsalva maneuver being performed for greater than 5 seconds. If holding your breath and straining for 5 seconds is dangerous, I don’t know how any pregnant woman has a bowel movement, or I don’t know...gives birth.
We already touched on this in Part 1, but exercise does not increase your risk for preterm labor if you have a normal pregnancy. I know at around 36 weeks I was secretly hoping it did, but it doesn’t. Exercise may cause Braxton-Hicks contractions, but as long as they are not painful or regular, and ease when you cease activity or change positions, they are not worrisome. Don’t be that girl who rushes to the hospital with her hospital bag because her uterus twitched from bending over and standing back up. But if you’re at all concerned, give your doctor a call. And once again, this article does not apply to you if you have a history of preterm labor, placenta previa, preeclampsia, are pregnant with multiples, or have an otherwise high-risk pregnancy.
So what if you are trying to become pregnant? (Don’t do it! Kidding. Screaming babies are a delight). You may have concerns about how training will affect your ability to get pregnant, which is completely valid. Some studies have, in fact, shown a correlation between infertility and women who participate in regular strenuous exercise. We’re talking every single day to the point of near total exhaustion. These studies do not apply to women who lift incrementally loaded barbells 3-5 times a week for 1-2 hours. In fact, strength training 2-3 times a week can help regulate hormone levels that are important for fertility, such as progesterone (which I know we all love to hate). What I tell any client who is wanting to get pregnant is to continue to do the program, eat like a strength athlete, and get as strong as you can now.
Did someone say, eat? Why, yes I did. Training will not reduce fertility so long as you are not in a severe caloric deficit with very low body fat levels. Regardless of whether or not you are trying to become pregnant, as soon as you pick up a barbell, you need to eat in a way that supports your goal of getting stronger. That means getting enough protein, so for most women I suggest tracking your macronutrients. If you want to continue to track while pregnant, that’s great. It may help you make sure that you’re gaining weight at an appropriate pace and eating a well-rounded diet. I personally did not track while pregnant, because I had enough experience tracking macros to eat intuitively and enjoy a small treat every now and then. Just kidding, I know I’m not fooling any of you.
Now that I got all of the research and official recommendations out of the way, let’s move on to the stuff that you probably came here for, which is suggestions on modifications you can make to your lifts and programming so that you can continue training until you either deliver or just don’t feel like doing anything anymore ;) Stay tuned for Part 3!
Dr. Elizabeth Zeutschel is a PRS Strength Coach, licensed physical therapist and certified Starting Strength Coach who resides with her husband and daughter in Meridian, Mississippi. You can contact her at firstname.lastname@example.org and on Instagram at @liz_nicole25