If you’ve been told to “take it easy” since the moment you saw two pink lines, you’re not alone. You’ve probably heard plenty of well-meaning advice: don’t lift anything heavy, keep your heart rate under 140, never lie on your back. Some of it is outdated and some was never quite right. Here’s what the American College of Obstetricians and Gynecologists (ACOG) actually says, in plain words, so you can talk it through with your provider and move with confidence.
The short answer: most pregnant women should be moving
ACOG’s current guidance on exercise in pregnancy is Committee Opinion No. 804 (2020). Its central message is encouraging. For women with uncomplicated pregnancies, physical activity is considered safe and beneficial, and they should be encouraged to do aerobic and strength-conditioning exercise before, during, and after pregnancy.
The target matches the general adult guideline from the U.S. Department of Health and Human Services: at least 150 minutes of moderate-intensity aerobic activity per week. That works out to about 30 minutes on five days, but you can split it however suits your life.
The 2019 Canadian guideline for physical activity throughout pregnancy (Mottola et al., published in the British Journal of Sports Medicine) arrives at the same number. It recommends at least 150 minutes of moderate activity spread over a minimum of three days, and ideally some movement every day. Its authors reviewed a large body of research and found that prenatal exercise was linked to lower odds of gestational diabetes, preeclampsia, and gestational hypertension, with no increased risk of miscarriage, preterm birth, or low birth weight in healthy pregnancies.
Evidence note
ACOG also notes that regular exercise in pregnancy is associated with benefits like reduced risk of excessive gestational weight gain, possibly shorter labor, and a lower chance of cesarean delivery. It may also help with low back pain, sleep, and mood. We’re not saying this to pressure you. The research just consistently points toward movement being good for you and baby.
How hard is “moderate”? Ditch the 140 bpm rule
The old advice to keep your heart rate under 140 beats per minute came from 1985 guidance that was dropped decades ago. Pregnancy changes your resting heart rate and how your heart responds to effort, so a single number doesn’t fit everyone. ACOG now points to two simpler tools:
- The talk test. You should be able to carry on a conversation while exercising. If you can talk but couldn’t comfortably sing, that’s about right.
- Rating of perceived exertion (RPE). On the 6–20 Borg scale, aim for around 13–14, which is “somewhat hard.” On a simpler 1–10 scale, think 5 or 6 out of 10.
If you were very active before pregnancy, including running or more vigorous training, ACOG says you can generally continue with your provider’s guidance. If you were mostly inactive before, this is a great time to start. Begin gently with 10–15 minutes and build gradually.
What counts? Activities ACOG considers safe
Walking
Accessible, low-impact, and easy to fit around your day. A brisk walk counts as moderate activity.
Swimming & water aerobics
The water supports your growing belly and takes pressure off your joints, which many women love in the third trimester.
Stationary cycling
Cardio with very little fall risk. Raise the handlebars as your bump grows.
Strength training & modified yoga or Pilates
Resistance exercise is explicitly recommended. Adjust positions and loads as you go.
ACOG notes that running or jogging can usually continue for women who ran regularly before pregnancy, and racquet sports may be fine for experienced players, with extra attention to balance as your center of gravity shifts.
What about lifting weights?
This is where the myths are most persistent. ACOG and the Canadian guideline both recommend resistance training as part of a healthy prenatal routine. Strength work helps you carry a growing baby, handle the physical demands of labor, and get ready for the thousands of lifts, carries, and car-seat maneuvers that come after birth.
Some practical guidelines for lifting during pregnancy:
- Leave reps in the tank. Finish most sets feeling like you could do 2–3 more good reps.
- Breathe through the effort. Exhale as you lift. Avoid long, forceful breath-holding (the Valsalva maneuver), especially as pregnancy progresses.
- Watch for coning or doming. If you see a ridge along the midline of your belly, adjust the exercise, lighten the load, or change your position.
- Pay attention to your pelvic floor. Heaviness, pressure, or leaking during a lift tells you to regress the move.
Our pregnancy exercise program walks through how to adapt strength training trimester by trimester.
Lying on your back: the real story
After about 20 weeks, lying flat on your back can let the weight of the uterus press on the vena cava, the large vein that returns blood to your heart. In some women this causes lightheadedness or a drop in blood pressure. ACOG advises avoiding the supine (flat-on-your-back) position as much as possible during exercise.
In practice, that doesn’t mean panicking if you wake up on your back. It means swapping flat floor exercises for alternatives: an incline bench instead of a flat bench press, side-lying or elevated glute bridges, and supported reclined positions on a wedge or pillows. If you feel dizzy, nauseated, or short of breath while reclined, roll onto your side.
Activities to avoid
ACOG lists a handful of activities to skip during pregnancy:
- Contact sports like ice hockey, boxing, soccer, and basketball, because of the risk of abdominal trauma.
- Activities with a high risk of falling, such as downhill skiing, water skiing, surfing, off-road cycling, gymnastics, and horseback riding.
- Scuba diving, because of the risk of decompression sickness for the baby.
- Skydiving.
- “Hot” yoga or “hot” Pilates, because of the risk of overheating.
ACOG also advises caution with exercise at high altitude (above about 6,000 feet) if you’re not already living there and acclimatized. In any setting, stay hydrated, dress in layers, and avoid exercising in very hot, humid conditions.
Stop exercising and call your provider if you notice:
Vaginal bleeding · regular painful contractions · fluid leaking from the vagina · shortness of breath before you start exercising · dizziness or feeling faint · headache · chest pain · muscle weakness that affects your balance · calf pain or swelling. These are the warning signs listed by ACOG.
When exercise may not be safe
Exercise isn’t right for every pregnancy. ACOG lists conditions where aerobic exercise is contraindicated. They include certain types of significant heart disease, restrictive lung disease, cervical insufficiency or a cerclage, multiple pregnancy at risk of premature labor, persistent bleeding in the second or third trimester, placenta previa after 26 weeks, premature labor or ruptured membranes during the current pregnancy, preeclampsia or pregnancy-induced high blood pressure, and severe anemia.
ACOG also lists “relative” contraindications, where exercise may still be possible with careful, individualized guidance. Examples are poorly controlled type 1 diabetes, thyroid disease, or high blood pressure, significant under- or overweight, heavy smoking, and some other medical conditions. The takeaway: have the conversation with your provider early, ideally at your first prenatal appointment, and check in again if anything changes.
A sample week that meets the guideline
| Day | Focus | Details |
|---|---|---|
| Monday | Strength | 25–30 min full-body: squats to a box, incline push-ups, rows, side-lying leg work |
| Tuesday | Walk | 30 min brisk walk (talk-test pace) |
| Wednesday | Mobility & breath | 20 min gentle prenatal yoga, pelvic floor contract-and-relax practice |
| Thursday | Strength | 25–30 min: split squats, glute bridges on a bench, band pull-aparts, carries |
| Friday | Cardio | 30 min swim, stationary bike, or walk |
| Saturday | Family movement | A long walk, a hike on easy terrain, or a trip to the park |
| Sunday | Rest | Rest and recover. Gentle stretching if it feels good. |
This week includes roughly 150–180 minutes of moderate activity. On days when nausea, fatigue, or life gets in the way, doing less still counts. Progress over perfection, always.
Postpartum: when can you start again?
ACOG notes that for many women, it’s reasonable to begin or resume exercise gradually soon after an uncomplicated vaginal delivery, once they feel ready and their provider agrees. After a cesarean birth or a complicated delivery, the timeline is longer and more individualized. Start with walking, breathing, and pelvic floor work, then rebuild strength progressively. Our Pelvic Floor 101 and diastasis recti guides on the blog are good next reads.
Frequently asked questions
Can I start exercising if I wasn’t active before pregnancy?
Yes, in most cases. ACOG encourages previously inactive women with uncomplicated pregnancies to start. Begin with short, easy sessions (10–15 minutes of walking, for example) and gradually build toward 150 minutes per week. Check with your provider first.
Is it safe to do ab exercises while pregnant?
Core training can be very helpful. Focus on breathing, deep-core engagement, and anti-rotation or carrying exercises rather than crunches and sit-ups, and avoid long periods flat on your back after mid-pregnancy. If you see doming along the midline, modify the move.
Will exercise hurt my baby?
For healthy pregnancies, research reviewed by ACOG and the Canadian guideline authors has not found that moderate exercise increases risk of miscarriage, preterm birth, or low birth weight. That’s reassuring, and it’s also why individualized advice from your provider matters if your pregnancy has any complications.
If you’d like a structured plan that takes the guesswork out of each trimester, with progressions, swaps, and safety cues built in, our guide is designed exactly for that.
You can also grab our free Prenatal Exercise Safety Checklist to keep on your fridge or in your gym bag.
A gentle reminder
This article is educational and is not medical advice. Every pregnancy is different. Please talk with your OB, midwife, or healthcare provider before starting or changing an exercise routine, especially if you have any medical conditions or pregnancy complications. See our medical disclaimer.
Sources & further reading
- American College of Obstetricians and Gynecologists. Physical Activity and Exercise During Pregnancy and the Postpartum Period. Committee Opinion No. 804. Obstetrics & Gynecology, 2020.
- Mottola MF, Davenport MH, Ruchat SM, et al. 2019 Canadian guideline for physical activity throughout pregnancy. British Journal of Sports Medicine, 2018;52:1339–1346.
- U.S. Department of Health and Human Services. Physical Activity Guidelines for Americans, 2nd edition. HHS, 2018.
- World Health Organization. WHO Guidelines on Physical Activity and Sedentary Behaviour. WHO, 2020.
- American College of Obstetricians and Gynecologists. Exercise During Pregnancy (patient FAQ). ACOG.
Mom, designer and founder of Steady & Strong Wellness. Katelyn researches every article from official guidelines and peer-reviewed studies, and always encourages readers to partner with their own healthcare providers.
@steadyandstrongwellness
