Focus on Fitness: Exercise During Pregnancy
By Kayli Anderson, MS, RDN, DipACLM, ACSM-EP
Today’s Dietitian
Vol. 25 No. 2 P. 46

These guidelines, benefits, and strategies can help clients do it safely.

Exercise during pregnancy is a controversial combination that provokes many questions. Several newly pregnant women wonder, “Is it safe for me to exercise? Can I continue the activities I enjoyed prepregnancy? Is it a bad time to start a new routine?”

The idea that exercise is harmful or unsafe during pregnancy is a myth. Not only is exercise safe for most pregnant women but it also offers a host of benefits, which is why encouraging pregnant clients to exercise is important. As of 2018, only 27.3% of pregnant women met the minimum physical activity recommendations.1 Whether clients were avid exercisers prepregnancy or mostly sedentary, RDs can guide them in establishing a safe routine that nourishes them (and their growing baby).

Benefits of Exercise
Exercising during pregnancy is associated with lower risks of complications such as preeclampsia and gestational diabetes. In fact, women with higher levels of preconception and early pregnancy physical activity have a 20% to 35% reduced risk of developing preeclampsia.2 Exercising during pregnancy also helps lessen common pregnancy symptoms such as backaches, constipation, difficulty sleeping, and swelling. Another perk? Exercise may contribute to easier labor and delivery. Staying active during pregnancy is associated with a decreased need for pain medication, shorter labor, lower rates of episiotomy, reduced rates of Cesarean delivery, and a lesser need for other medical interventions.3 A pregnant woman’s mental health also benefits from more physical activity. In one study, women who met the weekly physical activity recommendations during pregnancy had lower rates of postpartum depressive symptoms compared with women who were sedentary during pregnancy.4 Exercise also may benefit the baby, contributing to a decreased risk of future asthma, allergies, diabetes, and hypertension.3

Exercise Guidelines
According to the American College of Obstetricians and Gynecologists, physical activity recommendations during pregnancy are the same as prepregnancy: 150 minutes of moderate-intensity aerobic activity per week.5 Exercise can be performed 30 minutes per day, five days per week or broken into smaller chunks such as 10-minute stints three times per day. Moderate-intensity exercise is any activity during which one can talk normally but can’t sing. Examples of moderate-intensity aerobic exercise include swimming, brisk walking, biking on a flat surface, and yard work. It’s important to tailor these general guidelines based on a person’s prepregnancy activity level.

Sedentary Women Before Pregnancy
If a pregnant woman is new to exercise, advise her to gradually build up to 150 minutes per week. They can begin with low-intensity activities such as walking or biking at a slower pace, yoga, low-intensity swimming, or tai chi for five minutes per day. During low-intensity exercise, clients should be able to hold a conversation and sing without needing to stop to catch their breath. Each week, encourage clients to add five minutes to each exercise period until they can sustain 30 minutes of continuous movement.

Light-Moderate Exercisers Before Pregnancy
Pregnant women who performed moderate-intensity exercise prepregnancy can continue their prepregnancy exercise routine, provided it’s safe and their health care provider has given them the green light. Other moderate-intensity activities that are safe during pregnancy include dancing, riding a stationary bike, and yoga or Pilates modified to accommodate changing body shape and balance. Water-based movement, like water aerobics, is beneficial during pregnancy because of the joint and muscle support water provides.

Vigorous Exercisers Before Pregnancy
What if someone was an avid weightlifter or endurance athlete before pregnancy? The good news is active clients can continue their vigorous activities as long as the exercises are pregnancy-safe and continue to feel good. Vigorous exercise includes any activity during which clients can speak only a few words before needing to pause to catch their breath. Pregnancy-safe vigorous activities include running, cycling, strength training, and hiking. For clients who continue to engage in vigorous activity, ensure they’re meeting their higher nutrition needs and they’re not displaying signs of disordered exercise behavior. In addition, identify changes in their overall health that may require them to scale back on exercise intensity or frequency.

Exercises to Avoid During Pregnancy
Although physical activity offers an array of benefits during pregnancy, not all activities are safe. Pregnant women should avoid activities that pose a risk of abdominal trauma or falling, such as downhill and water skiing, horseback riding, and contact sports. Moreover, they should avoid exercise in hot or humid environments such as hot yoga. During pregnancy, hormones cause ligaments to become more mobile, increasing the risk of overstretching and injury. Because of this, activities that include excessive jumping, bouncing, and deep stretching should be modified or avoided. Pregnant women also shouldn’t perform exercises that require them to lie flat on their back for prolonged periods of time, especially in the second and third trimesters. This position puts pressure on the vena cava and can restrict blood flow. Most back-lying exercises can be modified by performing them side-lying, sitting, or by propping the body up on an incline with pillows or a yoga bolster.

Body Changes That Impact Exercise
It’s no secret that the body goes through profound changes during pregnancy, but how do these changes impact exercise? Thanks to the hormone relaxin, increased joint flexibility during pregnancy can make pregnant clients more prone to injury. Make sure clients are aware of this increased flexibility, so they don’t overstretch during exercise. Another change that occurs is a shift in the center of gravity. As the uterus grows from about the size of an orange to the size of a watermelon, the center of gravity constantly changes. Advise clients to choose exercises that enable them to feel stable and modify balance-based exercises by steadying themselves against a wall or performing the exercise seated. What’s more, their lungs must share space with the increased size of their uterus, which may make breathing more difficult. And since oxygen needs increase during pregnancy, the increased demands on the respiratory system can make vigorous exercise much more challenging. Encourage clients to pay attention to how they’re feeling during exercise and to rest as needed.

Helping Clients Exercise Safely
The following tips can help clients incorporate exercise into their prenatal self-care so they and their baby can safely reap the benefits.

Get the “Okay” From Their Medical Provider
Ensure clients have received the “OK” to exercise from their medical provider. While exercise is safe and beneficial in uncomplicated pregnancies, it’s contraindicated in women with severe anemia, certain heart and lung problems, severe preeclampsia, and risk of preterm labor.3

Match Recommendations to Activity Levels Before and During Pregnancy
Tailor the general recommendations of 150 minutes per week of activity based on the client’s activity level before pregnancy. Evaluate the activities they’re interested in to ensure they’re pregnancy-safe and match their current capabilities for exercise. If clients are new to exercise, help them create a plan to gradually build up to recommendations.

Include a Warm-Up and Cool-Down
With the many changes in joint flexibility, balance, temperature regulation, and breathing, a proper warm-up and cooldown are more important than ever. This can include gentle walking, stretching, and breathing.

Discuss Their Motivations for Exercise
For some people, exercise may be entangled in unhealthful behaviors. With so many physical and emotional changes, pregnant women are more susceptible to developing a disordered relationship with exercise. Talk to clients about their motivations to exercise and look for red flags such as a strong desire to control their appearance or weight. Encourage them to identify exercise benefits that have nothing to do with control or appearance, such as better sleep or reduced morning sickness. Create a compassionate and nonjudgmental environment for clients to discuss stressors and concerns, and refer them to a mental health professional for additional support as needed.

Encourage Regular Check-Ins With Their Bodies and Adjust Exercise Accordingly
The body is constantly changing during pregnancy, and exercise routines will need to roll with these changes. Encourage clients to check in with themselves before, during, and after exercise to see how they’re feeling and how certain types of exercise and intensities affect them at different stages of pregnancy. Help them adjust their routines so they can continue to comfortably exercise throughout their pregnancy. This may include trying different activities or modifying the activities they’re already doing. Educate them on the warning signs for when to stop exercise immediately: vaginal bleeding, abdominal pain, regular or painful contractions, swelling, difficulty breathing, dizziness, chest pain, or headache.5

Fuel Exercise With Adequate Nutrition and Hydration
Nutrition needs increase during pregnancy, with some nutrient requirements increasing by as much as 50%. Make sure active clients are meeting needs for the demands of exercise and pregnancy. They should never begin exercising on an empty stomach and should plan to eat a balanced meal or snack immediately after a workout. A nutritious pre- or postexercise snack may include a smoothie made with fruit, nuts and seeds, and greens; whole grain avocado toast; or a grain bowl with sauteed veggies and a calcium-rich tahini sauce. Hydration during pregnancy also is critical since it helps support increased blood volume and forms the amniotic fluid around the baby. Pregnant women should aim for at least 8 to 12 cups of water per day plus more if they’re exercising. Advise clients to drink plenty of water before and after exercise and carry a water bottle during longer bouts of physical activity.

— Kayli Anderson, MS, RDN, DipACLM, ACSM-EP, is the founder of the women’s health blog Plant-Based Mavens ( and coauthor of the lifestyle medicine textbook Improving Women’s Health Across the Lifespan.


1. Perak AM, Ning H, Khan SS, Van Horn LV, Grobman WA, Lloyd‐Jones DM. Cardiovascular health among pregnant women, aged 20 to 44 years, in the United States. J Am Heart Assoc. 2020;9(4):e015123.

2. Aune D, Saugstad OD, Henriksen T, Tonstad S. Physical activity and the risk of preeclampsia: a systematic review and meta-analysis. Epidemiology. 2014;25(3):331-343.

3. Tollefson M, Eriksen N, Pathak N, eds. Improving Women’s Health Across the Lifespan. CRC Press; 2021.

4. Shakeel N, Richardsen KR, Martinsen EW, Eberhard-Gran M, Slinning K, Jenum AK. Physical activity in pregnancy and postpartum depressive symptoms in a multiethnic cohort. J Affect Disord. 2018;236:93-100.

5. Physical activity and exercise during pregnancy and the postpartum period: ACOG Committee Opinion, Number 804. Obstet Gynecol. 2020;135(4):e178-e188.