Exercising During Pregnancy: What's Safe and What to Skip

Nothing looks quite as bad ass as a pregnant person lifting weights. Growing muscle while growing a human is no small feat. But there's been a lot of confusion and misinformation around exercising during pregnancy that might make it seem safer to just avoid it altogether — but that would be a mistake. 

According to the American College of Obstetrics and Gynecologists (ACOG) staying active during pregnancy is safe, but it's also one of the best things you can do for yourself and your baby. Research consistently shows that exercise reduces the risk of complications, supports a smoother delivery, and helps you feel stronger throughout all three trimesters and postpartum.

Why Exercise During Pregnancy Matters

Sticking with your exercise routine (or starting a new one) while pregnant has a ton of benefits, like cutting the likelihood of needing a cesarean section by 34%, reducing the risk of developing gestational diabetes by 40%, lower risk of preeclampsia (risky condition with high blood pressure) and depression, and a shorter first stage of labor.

Guidelines recommend at least 150 minutes of moderate-intensity activity per week, or about 30 minutes a day, five days a week. The key is knowing how to adjust your training, what to skip, and how to listen to your body as it changes.

What's Safe and What's Not When Exercising While Pregnant?

There are a lot of confusing messages out there around what you can and can't do during pregnancy workouts. A lot of the classic advice has changed over the last decade or so. Here's the most recent info.

Can Exercise Cause Miscarriage?

This is the question that stops many women from staying active, but the short answer is that exercise does not increase your risk of miscarriage. 

A recent systematic review involving nearly 3,800 women found no association between exercise during pregnancy and miscarriage risk. Women who exercised had the same miscarriage rates as those who didn't, and other studies have come to the same conclusion. So, if you have no medical contraindications, you can exercise safely throughout pregnancy without fear of harming your baby.

Can You Lie On Your Back While Exercising During Pregnancy?

You'll still find sources that say to avoid laying on your back to exercise after the first trimester, but that's not a strict rule. The ACOG says short durations of supine exercise is fine, so long as you feel ok, though you might want to make adjustments, like laying at a slight upward angle or tilt for comfort. 

In a 2025 study, researchers found "highly active women, especially those with resistance training experience, can safely engage in a heavy-load resistance protocol, including supine exercise, without jeopardising fetal well-being." 

Always monitor for dizziness, nausea, breathlessness, chest discomfort, or uterine cramping and stop right away if you experience any of them.

What Is a Safe Heart Rate During Pregnancy?

The old rule about keeping your heart rate under 140 bpm is outdated. Current guidelines no longer use a specific heart rate ceiling because every woman's baseline fitness is different. 

Some sources recommend using the "talk test" as your guide, and if you can carry on a conversation while exercising to ensure you're in the moderate-intensity zone. However, the ACOG says how intense your exercise should be depends on your fitness level and symptoms. Regardless, it's crucial to stay hydrated, and prevent overheating.

In fact, 2025 in the British Journal of Sports Medicine had pregnant women complete 3x8 repetitions with one repetition in reserve in sumo deadlift, bench press and incline bench press while monitoring maternal and fetal heart rate during lifting, and maternal blood pressure, glucose and lactate before and after. They found no issues, stating "high-intensity resistance exercises are well tolerated by both mother and fetus, including while using the Valsalva manoeuvre." Of course, speak to your doctor before trying heavy lifts or intense exercise while pregnant, especially if you're new to intense exercise.

How Much Can You Lift While Pregnant?

If you lifted before pregnancy, you can generally continue lifting to maintain or build muscle and strength during pregnancy, though you'll likely need to modify as your body changes. As the research discussed above found, resistance training, including compound lifts like squats, deadlifts, and presses, is safe for women with uncomplicated pregnancies.

Here's what to keep in mind:

• Listen to your body. If something feels wrong, stop. Pregnancy isn't the time to chase PRs.

• Adjust your breathing. The Valsalva maneuver (holding your breath during heavy lifts) was once discouraged, but new research shows it's safe and can actually protect your cardiovascular system during lifts.

• Modify as needed. As your belly grows, switch to variations that accommodate your changing center of gravity. Goblet squats, landmine presses, and sumo stances often feel better than traditional positions.

• Keep 1-3 reps in reserve. Train with effort but don't push to failure.

There's no universal weight limit because strength varies so much between individuals. A 200 lb deadlift might be moderate for one woman and maximal for another. Focus on relative intensity rather than absolute numbers.

Ready to return to training after delivery? Check out our guide: Moms Who Lift: Training After You Have a Baby.

Low Impact Exercises for Pregnant Women

Low impact training keeps at least one foot on the ground, reducing joint stress while your body produces relaxin (the hormone that loosens ligaments). Great options include:

• Walking. Aim for 30-45 minutes most days.

• Swimming and water aerobics. Buoyancy takes pressure off joints and lower back.

• Stationary cycling. Eliminates fall risk as your balance shifts.

• Prenatal yoga and Pilates. Studies show yoga can shorten labor and reduce pain.

• Elliptical and rowing. Smooth movements that build cardio without impact.

Exercises to Avoid While Pregnant

Some activities carry unnecessary risk. Skip these:

• Contact sports like basketball, soccer, and hockey

• High fall-risk activities including skiing, horseback riding, and outdoor cycling

• Hot yoga or exercising in extreme heat

• Scuba diving and high-altitude activities above 6,000 feet

If you experience vaginal bleeding, dizziness, chest pain, calf swelling, or regular painful contractions, stop exercising and contact your healthcare provider.

Takeaway

Exercise during pregnancy supports your health, your baby's development, and your delivery outcomes. You don't have to take on an intense routine while you're pregnant, but if you want to keep lifting, all signs point to it being safe and beneficial. Walking daily, swimming laps, yoga classes, or continuing your strength training routine, are all great options. Start where you are, modify as your body changes, and stay consistent. Right now, peak performance isn't the goal, it's building a strong foundation for labor, recovery, and the demands of new motherhood.

FAQs

Can I start exercising during pregnancy if I wasn't active before? 

You can start exercising during pregnancy even if you weren't previously active. Start with low-intensity activities like walking for 5-10 minutes and gradually increase. The ACOG encourages all pregnant women without contraindications to be physically active.

Will exercise make my baby too small? 

Exercise will not make your baby too small. Research shows no significant difference in birth weight. Exercise does reduce the risk of having an overly large baby (macrosomia), which can complicate delivery.

Is weightlifting safe during pregnancy? 

Weightlifting is safe for most women with uncomplicated pregnancies. Resistance training helps you retain muscle mass, supports joint stability, and makes daily activities easier. You might need to modify exercises as your body changes.

When should I stop exercising during pregnancy? 

Stop immediately if you experience vaginal bleeding, fluid leaking, chest pain, severe headache, dizziness, or regular contractions before 37 weeks. Absolute contraindications include placenta previa, preterm labor, ruptured membranes, and severe preeclampsia.