Exercising during pregnancy: Everything you need to know

Oct. 5, 2022
Pregnant woman exercising.
Exercising during pregnancy is encouraged and has many healthy benefits. Photo: Getty Images.

Now that you’re expecting a baby, you may have questions about how often you should exercise, or even whether you should continue to exercise while carrying your child.

The good news is: Regular exercise is generally safe during pregnancy. It’s even recommended.

To help you understand pregnancy and exercise, we consulted with Dr. Lauren Harrington, an OB/GYN who is passionate about helping women lead healthy, informed and empowered lives.

Harrington is a former varsity college tennis player who speaks English and Spanish, and is an assistant professor at the University of Colorado School of Medicine.

Dr. Harrington answers questions that you may have about exercising during pregnancy:

How safe is exercise during pregnancy? 

Dr. Lauren Harrington
Dr. Lauren Harrington

“Exercise in pregnancy is safe and encouraged. Individuals who do not have high-risk pregnancies can safely engage in moderate-intensity exercise without an increased risk of miscarriage or preterm birth,’’ Harrington said.

  • Because pregnancy has higher metabolic demands, it is very important to maintain hydration and temperature control while exercising.

Why is it important to exercise during pregnancy? 

“Exercise in pregnancy has important benefits for overall physical health including strength, flexibility, balance, endurance and cardiovascular health,’’ Harrington said. “Exercise is also great for psychological well-being. What’s more, there are additional benefits that are unique to pregnancy and the postpartum period.

“Exercise in pregnancy helps avoid excessive weight gain. For an individual with a normal BMI at the start of pregnancy, we recommend gaining a total of 25 to 35 pounds.’’

Individuals who stay active through pregnancy are more likely to:

  • Give birth to a baby of normal weight.
  • Have a spontaneous vaginal birth without the assistance of forceps or vacuum.
  • Gain the recommended amount of weight during pregnancy.
  • Have a term delivery.
  • Maintain normal blood pressure during pregnancy.
    • Additionally, many of the aches and pains of pregnancy (e.g. back pain or pelvic pain) can be mitigated by staying active.
    • Exercise is also an effective way to prevent or manage diabetes during pregnancy.
    • Exercise over the postpartum period may also be an important tool in managing postpartum anxiety and depression.

“I recommend listening to your body. It is normal for endurance to decrease as you get further along in pregnancy. If you experience contractions, persistent abdominal pain, decreased fetal movement, abdominal trauma, loss of amniotic fluid, vaginal bleeding, dizziness or chest pain while exercising, please immediately stop exercise and call your doctor,’’ Harrington said.

What kinds of exercises are safe during pregnancy? 

  • Safe exercises in pregnancy include: walking, stationary bike, aerobics, dancing, aquatic exercise, stretching (i.e. prenatal yoga) and resistance exercises (with weights less than 10 pounds).
  • Elite and competitive athletes can work with their obstetrics provider to fashion a personalized exercise plan that is safe for pregnancy.

What are some popular aerobic activities and healthy ways to exercise during pregnancy?

“Aquatic exercise in a pool is very popular among my patients and is particularly well-suited to pregnancy because being submerged in water helps keep the core body temperature normal, softens the impact on joints and ligaments, and reduces swelling in the legs,’’ Harrington said. “While pool exercise is safe and encouraged, scuba diving during pregnancy should be avoided.’’

In which month should I start exercising during pregnancy? 

  • You can exercise at any point in pregnancy.
  • For individuals with pregnancy at risk for fetal growth restriction (a small baby) or preterm delivery, it’s recommend to decrease exercise intensity in the second and third trimesters.

Which exercises should be avoided during pregnancy?

“There are a few modifications and precautions that I recommend for my pregnant patients,’’ Harrington said.

  • Avoid lying flat on your back for extended periods of time after the first trimester. This is because the enlarged uterus can compress major blood vessels.
  • Be aware that hormones of pregnancy cause ligaments and joints to be more flexible and loose, so you are at higher risk for injury (e.g. while performing activities that involve quick changes in direction or jumping).
  • Avoid high-impact activities that could cause direct blunt force trauma to the abdomen or pose a risk of falling (contact sports, such as ice hockey, or outdoor biking and horseback riding). Trauma to the abdomen can cause a placental abruption, which can be life threatening for both mother and baby.
  • Avoid exercising in hot environments (outdoor temperatures above 90 degrees, high humidity, or hot yoga). Data suggests that keeping your temperature below 102 F is important for both maternal and fetal health (especially in the first 4-6 weeks of pregnancy). It is important to maintain hydration and take precautions to regulate temperature (wear loose-fitting clothing, exercise indoors with air conditioning).
  • When weight training, use low-intensity, low-resistance free weights or machine weights less than 10 pounds. Avoid significant straining, valsalva maneuvers, isometric exercises, and high-resistance weights.

If you have certain conditions, should you avoid excising during pregnancy?

According to Up to Date, pregnant individuals with the following conditions should not exercise during pregnancy:

  • Heart disease
  • Restrictive lung disease
  • Cervical shortening with or without a cerclage present
  • Twin pregnancy (or higher order multifetal gestations)
  • Persistent vaginal bleeding
  • Placenta previa (after 26 weeks’ gestation)
  • Premature labor
  • Ruptured membranes
  • Elevated blood pressure of pregnancy (pre-eclampsia or gestational hypertension)
  • Severe anemia

What conditions should I ask my provider about before exercising?

  • Poorly controlled diabetes, high blood pressure, seizures or hyperthyroidism
  • Growth restricted fetus
  • Tobacco use
  • Obesity (BMI of 40 or higher)

How much exercise is safe during pregnancy? 

“We do not have a lot of data about what constitutes too much exercise in pregnancy,’’ Harrington said. “Pregnant individuals who perform a moderate-intensity exercise for more than 45 minutes should pay particular attention to hydration and temperature control.

“For most of my patients, I recommend light-to-moderate intensity exercise. During moderate-intensity exercise, you should be able to maintain a normal conversation. If you are so winded that you are speaking in only two- to three-word sentences, this is considered high-intensity exercise,’’ Harrington said.

She added that it is safe for individuals to start a new exercise program once they become pregnant if they have an appropriate medical clearance by their obstetrics provider, and if they slowly (low-intensity exercise for 10-20 minutes three times weekly), and gradually build up the intensity of their activity.

  • Individuals engaging in high-intensity exercise should consult with their providers to create a safe activity plan together.

How much exercise is healthy when you’re pregnant? 

I generally recommend light- to moderate-intensity exercise for 30 minutes, five to seven times weekly, with an additional 5 to 10 minutes before and after to stretch,’’ Dr. Harrington said.

Should I do any exercise in early pregnancy?

“Light-to-moderate-intensity exercise is safe in early pregnancy. I recommend avoiding intense strength training and heavy lifting at all stages of pregnancy, including early in pregnancy,’’ she said.

How long can I play sports while I’m pregnant? 

“Because of the risk of injury and abdominal trauma, I recommend avoiding contact sports during pregnancy. Professional athletes can work with their provider to make a plan that is safe for their pregnancy.’’ Harrington said.

Is jogging good for pregnant women? 

  • Jogging is a high-intensity exercise. If an individual has a pregnancy without medical complications and jogged regularly before pregnancy, it is safe to continue jogging during pregnancy with attention to temperature control and adequate hydration.

After my baby is born, what considerations should I have about exercise?

After you have your baby, your body generally returns to its pre-pregnancy physiologic function by six to eight weeks after delivery.

“If you have a vaginal birth, the timing for your return to exercise postpartum should be determined in consultation with your provider and is influenced by several factors including whether or not you have a perineal tear, elevated blood pressure, and/or anemia,’’ Harrington said. “After a cesarean delivery, you should wait at least four to six weeks and obtain clearance from your provider before gradually resuming exercise. Light to moderate exercises should not adversely impact your ability to successfully breastfeed your infant.

How will exercise affect me if I am breastfeeding?

“For a lactating individual, high-intensity exercise may lead to a decrease in milk production and/or an increase in lactic acid in breast milk, which may be less palatable to the infant,’’ Harrington said. “Nursing or pumping prior to exercise may be a useful strategy. Maintaining hydration is also important for maintaining milk supply.’’