Strength Training During Pregnancy: What You Need to Know
Learn what the science says about prenatal strength training, and how Tonal’s Functional Prenatal Strength program empowers moms-to-be.
Before I got pregnant, I prided myself on my athleticism. I ran marathons (even ultramarathons) and lifted heavy weights two or three times a week. I loved the way it made me feel—physically, yes, but maybe even more so mentally.
But with pregnancy, there were so many rules about what I couldn’t do. While the guidelines on what not to eat and drink seemed restrictive, at least they were clear. The advice on exercise felt much less conclusive, and I’m not the only one who’s confused: A 2023 study showed that only about one in four women are knowledgeable about exercise during pregnancy.
“It is definitely very common—even for folks who were fairly athletic before pregnancy—to be really scared of exercising during pregnancy,” said Gina Conley, MS, the author of Training for Two, a primer on strength-focused exercise during pregnancy, and founder of MamasteFit. Despite these common fears, continuing or starting to exercise during pregnancy is considered safe according to the American College of Obstetricians and Gynecologists (ACOG).
While trying to figure out what I could and couldn’t do during pregnancy made me feel powerless, strength training actually could have helped combat those feelings, according to Tonal’s lead programming specialist and mom Jenna Moore, MS, CSCS, a Pre & Postnatal Certified Coach.
As Tonal launches a new Functional Prenatal Strength two-week program — designed by Moore and coached by Betina Gozo Shimonek, CSCS, who is certified in prenatal fitness — it’s a great time to unpack what the experts really say about strength training during pregnancy.
What Are the Benefits of Strength Training During Pregnancy?
Despite myths and hesitations about exercise during pregnancy, Moore explained that a growing body of evidence suggests staying active improves health outcomes for both moms and babies.
According to ACOG, exercising during pregnancy can reduce the risk of developing gestational diabetes and preeclampsia, a serious and potentially fatal blood pressure condition. Strength training, the association also notes, can help with some common pregnancy complaints such as back pain—something about 60 percent of women report experiencing during pregnancy. Furthermore, prenatal physical activity was linked to a reduced need for cesarean section and shorter duration of labor in a 2023 review.
So far, the mental health benefits of exercise in pregnancy are not very well-studied, but a 2022 review of the literature found that exercise does seem to improve symptoms of depression and anxiety during the perinatal period.
Women’s health is notoriously understudied, so the science may not have completely caught up, but anecdotal evidence abounds: Ask most moms or moms-to-be if exercise helps their mental health, and you’ll hear a resounding “yes.” It’s a small but real way to engage in self-care during a wonderful but often stressful period of transition.
“I feel like the most important thing I’ve learned as a mother is that I have to show up for myself,” Shimonek said. “I have to serve myself before I can truly show up for those around me.”
Besides the physical and mental benefits, strength training also has practical implications, according to Moore. “Being strong going into motherhood is so important. You’re healing, but you’re also taking care of a human. You’re going to need some strength,” she said. “[You’ll need] the strength to get them in and out of the crib and, as the baby grows, that’s progressive resistance right there. They’re getting bigger so you’ve got to get stronger to keep up with them.”
What Are the Benefits of Functional Prenatal Strength?
Whether you’re a seasoned lifter or picking up weights for the first time—as long as your medical professional clears you for exercise—Functional Prenatal Strength will help you move with ease throughout your pregnancy. Specifically designed to be third-trimester-safe, the program can be joined during any stage of pregnancy and is geared toward strengthening your pelvic floor, promoting hip mobility, and preparing you for birth and the physical challenges of motherhood.
“We do of course want you to listen to your physician, your midwife, your OBGYN, and take their advice,” Moore said. “But we as pregnant women get told a lot of things we can’t do. We really wanted to empower women with this program, to say, ‘Here are all the things you can do.’”
In the program, you’ll find a variety of strength moves that you can do throughout your pregnancy, along with modifications to adjust every movement to your current fitness and comfort level. Shimonek starts each workout with prenatal specific breathwork. There’s also core work, which can be an area that’s specifically confusing for expecting moms.
“We do want to avoid situps and crunches. And by the third trimester, planks are probably really difficult without modification,” Moore said. As the baby grows, she explained, it’s putting pressure on your abdominal musculature. “And so when we do things like situps, we put extra pressure on an already-stressed muscle.” That can lead to conditions like diastasis recti, or the separation of the abdominal wall—something every pregnant woman experiences to a degree, but a larger separation means more time spent attempting to heal postpartum.
However, Moore said, there are ways to work your core without putting that extra pressure on your abdominals. “The suitcase march, standing and kneeling lifts and chops, birddogs, deadbugs—there’s a lot of core work that we’ve done in the Functional Prenatal Strength program that is perfectly safe for someone in their second or third trimester.”
“Everything is built around what you can do and what is going to make you feel the best during this time,” she said.
Even with modifications and a naturally slower pace, you can still expect an appropriate challenge in these workouts. Shimonek admitted that her favorite exercise in the program—the Bulgarian split squat with hip internal rotation—is “a doozy of a move,” but it’s certainly one that’ll leave you feeling empowered.
How Hard Should You Push Yourself in the Program?
In your non-pregnant life, a coach might have advised you to train to failure or close to it—in other words, lift heavy weights as many times as you can, until you could only manage one or two more reps. With prenatal training, Moore recommends that women should finish every set with around four to five reps in reserve (the number of reps you feel like you could safely do after finishing your set).
“We’re aiming to be moderately fatigued at the end of a set,” Moore explained. Meaning, we’re not maximally exerting ourselves, but we can still work hard.”
Conley agrees. “It’s kind of like, ‘I am fatigued, but I could do more if I wanted to.’”
For some neurotic overachiever types (guilty), this can be hard to accept. But you can still get a good workout in, Shimonek said. “You shouldn’t be setting PRs,” she said, “but you shouldn’t be afraid to challenge yourself to the best of your ability that day.”
What Are Some Red Flags to Watch For?
According to ACOG, you should put your workout on hold if you experience any of the following: vaginal bleeding; abdominal pain; regular, painful contractions; amniotic fluid leakage; shortness of breath; dizziness; headache; chest pain; muscle weakness affecting balance; calf pain or swelling.
More specifically to strength training, Conley says now is the time to really make sure you’re mastering good form—something that’s always important for injury prevention, whether or not you’re pregnant. “We’re not necessarily going to be able to lift as much weight as we did pre-pregnancy,” she said. “It’s going to be more about modifying to be comfortable in your body.”
The key is to learn to listen to your body, something Moore likens to a lesson in advocating for yourself. “It’s about really getting in tune with your body,” she said, “and saying, ‘I know what feels good for me, and I’m going to use that intuition and that knowledge to make the best decision for myself.’
The Bottom Line
Thinking back to my own pregnancy, I realize now I was overwhelmed by perceived limitations and restrictions. I grew tired of the judgmental looks I was getting in the gym, and I mostly gave up lifting weights in my second trimester. But now I’m realizing I may have stopped needlessly. For expecting moms, leaning into strength training can be safe, empowering, and beneficial to your physical and mental health.
“As a mother, and as a woman, this is the first opportunity you really have to advocate for yourself,” said Moore. “You’re going to have to advocate for yourself during labor and delivery and during those early postpartum days. So start advocating for yourself now.”
Always consult with your physician or health care professional before starting any fitness program while pregnant or postpartum.
Read More
Coaches
Betina Gozo Shimonek Inspires Moms to Feel Strong and Powerful
The expert prenatal coach busts myths about training through pregnancy and explains why moms-to-be should go heavy.
Science
4 Science-Backed Benefits of Strength Training for Every Athlete at Every Age
The health benefits of strength training are clear: You can live a longer, more fulfilling life with just two to three workouts a week.
Nutrition