Is exercising during pregnancy good for the baby?
In a pregnancy without complications, ACOG says physical activity is safe and desirable, with a target of about 150 minutes of moderate activity a week. The proven benefits are for you: lower risk of gestational diabetes, preeclampsia and cesarean birth, and less postpartum depression. That's good for your baby too. Talk to your provider before starting.
On this page
The short answer
For most pregnancies, yes. ACOG, the US obstetricians' group, says that in a pregnancy without complications, physical activity is "safe and desirable." WHO's 2020 activity guidelines include pregnant women, and Canada's 2019 guideline concluded that the benefits of activity in pregnancy are moderate and no harms were identified.
If you weren't active before, start small and talk with your provider before you begin. If you have complications, your provider will tell you what's right for you. If you were very active before, you can often keep going with changes: the main things to drop are contact sports, activities with a high risk of falls, and heat.
How it helps you, and through you the baby
ACOG lists these benefits of exercise in pregnancy:
- Lower risk of gestational diabetes
- Lower risk of preeclampsia
- Lower risk of cesarean birth
- Healthier weight gain
- Faster recovery after birth
- Lower risk of postpartum depression
Several of these matter for the baby as well. Diabetes in pregnancy has been linked to a 25 to 30% higher relative risk of autism and ADHD in children, across 202 studies covering 56 million pregnancies. That's an association, and the absolute increase is small, but steady blood sugar is one more reason to move. A parent's mood matters too: a calmer, less depressed parent is part of a child's health. See depression during pregnancy.
A fair note on mood. When the US Preventive Services Task Force weighed ways to prevent depression in pregnancy, counseling came out on top, and physical activity had limited or mixed evidence on its own. So move because it helps your body and lifts your day, and if your mood stays low for more than a couple of weeks, talk to your doctor or midwife as well.
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Movement and blood sugar
Gestational diabetes, a kind of high blood sugar that starts in pregnancy, affects 5% to 9% of US pregnancies each year. You'll usually be offered a test between 24 and 28 weeks. Being active lowers the risk, and if you are diagnosed, most women control it with changes to eating and activity alone.
Two cautions. Pregnancy isn't the time to try to lose weight; the goal is steady blood sugar, not a diet. And if you have diabetes or gestational diabetes, your care team should help set your activity plan alongside your food plan.
What about the baby's brain directly?
You may have seen headlines saying exercise in pregnancy makes "smarter babies." Here's what that's based on. In a tiny Montreal trial of 18 women, newborns of mothers who did at least 20 minutes of moderate cardio three times a week from the second trimester showed more mature brain responses to sound, measured by EEG, at 8 to 12 days old.
That's a promising hint. But no IQ or development was measured, and it needs repeating in bigger studies. So exercise for your own benefits, which are solid, and enjoy the possibility of a bonus.
How much: about 150 minutes a week
ACOG's target is about 150 minutes of moderate activity a week, spread across the week. That could be:
- 30 minutes on 4 days, or
- 25 minutes on 5 days, or
- about 20 minutes every day.
When you can, take those minutes outside. A walk in the park gets you movement, daylight and a break from screens in one trip, and it's free. Walk to the coffee shop instead of driving, take phone calls on foot, or find a regular loop near home. On hot days, go early or late, carry water and wear loose clothes; ACOG advises avoiding high heat and humidity.
Here's what a real week can look like:
| Day | Activity | Minutes |
|---|---|---|
| Monday | Brisk walk after dinner | 30 |
| Tuesday | Prenatal yoga class | 30 |
| Thursday | Swim or stationary bike | 30 |
| Saturday | Walk in the park with your partner | 40 |
| Sunday | Short walk and stretch | 20 |
| Total | 150 |
Partners can join in: a daily walk together is exercise, time outside and a chance to talk about the week, all at once.
What's usually fine, and what to avoid
| Usually fine (with your provider's OK) | Avoid |
|---|---|
| Walking | Long periods lying flat on your back |
| Swimming | Hot yoga, Bikram yoga, hot Pilates |
| Stationary cycling | Scuba diving, skydiving |
| Low-impact aerobics | Contact sports: hockey, soccer, basketball, football, boxing |
| Modified yoga and Pilates | High fall risk: skiing, surfing, off-road cycling, gymnastics, horseback riding |
| Running or jogging (if you ran regularly before) | High heat and humidity |
| Strength training (if you did it before) |
The "lying flat on your back" point links to sleep advice too. From 28 weeks, go to sleep on your side; see why side sleeping matters.
A prenatal yoga class adds people, routine and movement in one go, which also helps with stress. Our page on stress in pregnancy has more on what calms the system.
Stop and call your provider if...
ACOG lists warning signs that mean stop exercising and call your provider:
- Vaginal bleeding
- Regular painful contractions
- Fluid leaking
- Trouble breathing before you start
- Dizziness or a headache
- Chest pain
- Muscle weakness that affects your balance
- Calf pain or swelling
And as always in pregnancy: if your baby is moving less than usual, call your doctor, midwife or labor unit right away, day or night.
Do this
- Ask your provider whether your planned activities are fine for your pregnancy.
- Write four or five walks into this week's calendar, outside where you can.
- Aim for about 150 minutes a week, building up slowly if you weren't active before.
- Skip hot yoga, contact sports and anything with a high risk of falls.
- Learn the stop-and-call signs and keep your provider's number in your phone.
When to ask your doctor
Check with your doctor or midwife first if…
- You have any pregnancy or medical complications.
- You weren't active before pregnancy and are starting something new.
- You want to keep running or strength training (fine if you did it before; confirm with your provider).
Call your doctor now if…
- You have vaginal bleeding, fluid leaking or regular painful contractions.
- You feel dizzy, get a headache, have chest pain or trouble breathing.
- You have calf pain or swelling, or muscle weakness that affects your balance.
- Your baby is moving less than usual (call right away, day or night).
This page is general information, not medical advice. Every pregnancy and every child is different. Ask your doctor, midwife or pediatrician before changing supplements, diet or care.
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People also ask
Can exercise during pregnancy harm the baby?
In a pregnancy without complications, ACOG calls exercise safe and desirable, and Canada's 2019 guideline found no harms. Avoid contact sports, activities with a high fall risk, hot yoga, scuba diving and high heat. Stop and call your provider if you notice any warning signs.
Can I start exercising if I wasn't active before pregnancy?
Yes, with your provider's OK. Start small, for example short daily walks, and build toward about 150 minutes a week. Walking, swimming, stationary cycling and modified yoga are usually good places to start.
Does exercise in pregnancy help the baby's brain?
It may, but the evidence is early. In a tiny Montreal trial of 18 women, newborns of mothers who did regular moderate cardio showed more mature brain responses to sound, and that needs repeating in bigger studies. The solid benefits are for you: lower risk of gestational diabetes, preeclampsia, cesarean birth and postpartum depression, which matter for your baby too.
Is running okay while pregnant?
ACOG lists running or jogging as usually fine if you ran regularly before pregnancy, with your provider's OK. Avoid high heat and humidity, drink water, and stop and call if you have bleeding, dizziness, chest pain or other warning signs.