Pregnancy brings significant changes to the body, and many expectant parents wonder whether exercise is safe and beneficial during this time. The good news is that for most pregnancies, physical activity isn’t just safe—it’s highly recommended. According to the American College of Obstetricians and Gynecologists (ACOG), “In the absence of obstetric or medical complications or contraindications, physical activity in pregnancy is safe and desirable, and pregnant women should be encouraged to continue or to initiate safe physical activities.”
This article explores the benefits of exercise during pregnancy, recommended types and intensity levels, and important safety considerations to help you maintain a healthy, active pregnancy.
Benefits of Exercise During Pregnancy
Regular physical activity during pregnancy offers numerous benefits for both the pregnant individual and the developing baby:
- Reduced risk of gestational diabetes: Studies have shown that exercise can lower the chances of developing gestational diabetes by 28-59%.
- Lower risk of hypertensive disorders: Exercise is associated with a decreased risk of developing pregnancy-related high blood pressure conditions, including preeclampsia.
- Decreased likelihood of cesarean birth: Regular physical activity may increase the chances of a vaginal delivery.
- Better weight management: Exercise helps prevent excessive gestational weight gain.
- Improved mental health: Physical activity can reduce stress, anxiety, and depression during pregnancy.
- Relief from common discomforts: Exercise can help alleviate pregnancy-related low back pain, pelvic girdle discomfort, and other musculoskeletal issues.
- Enhanced overall fitness: Maintaining cardiovascular endurance, muscular strength, and flexibility supports a healthier pregnancy.
Exercise Recommendations During Pregnancy
Frequency and Duration
The American College of Obstetricians and Gynecologists (ACOG) recommends at least 150 minutes of moderate-intensity aerobic activity per week during pregnancy, ideally spread throughout the week. For those who were highly active before pregnancy, continuing vigorous-intensity exercise is generally considered safe, under healthcare provider supervision.
For previously sedentary individuals, it’s advisable to start with as little as 10 minutes of physical activity and gradually increase the duration.
Intensity
Exercise intensity can be monitored using:
- Talk test: You should be able to carry on a conversation while exercising at moderate intensity.
- Rate of perceived exertion: On the Borg Scale (6-20), aim for 13-14 (somewhat hard) for moderate exercise.
- Heart rate: While less commonly used now, some healthcare providers may recommend target heart rate zones based on age and fitness level.
Types of Safe Exercises
Aerobic Activities
- Walking: Perhaps the simplest and most accessible exercise, walking requires minimal equipment and can be adjusted in intensity and duration.
- Swimming and water aerobics: The buoyancy of water reduces stress on joints and helps manage body temperature. These activities are particularly beneficial for those experiencing back pain or joint discomfort.
- Stationary cycling: Provides cardiovascular benefits while minimizing risk of falls and joint stress.
- Modified aerobic classes: Classes specifically designed for pregnant participants can provide safe, guided workouts.
Strength Training
- Low to moderate resistance training: Using light weights (generally under 10 pounds) or resistance bands helps maintain muscle tone and strength.
- Body weight exercises: Modified squats, wall push-ups, and carefully adapted core exercises can maintain functional strength.
- Pelvic floor exercises: Kegel exercises strengthen the pelvic floor muscles, potentially reducing urinary incontinence and supporting postpartum recovery.
Flexibility and Mind-Body Exercises
- Yoga: Prenatal yoga can improve flexibility, strengthen muscles, and teach breathing techniques that may be helpful during labor. Avoid hot yoga and positions that may compromise balance.
- Modified Pilates: With appropriate adjustments, Pilates can support core strength and posture.
- Stretching: Gentle stretching helps maintain flexibility and may reduce muscle tension.
Exercises to Avoid or Modify
As pregnancy progresses, certain activities should be avoided:
- Contact sports or activities with high fall risk: Basketball, soccer, skiing, horseback riding, gymnastics, and similar activities carry increased injury risk.
- Hot yoga or exercise in high heat/humidity: These conditions may raise core body temperature to potentially unsafe levels.
- Scuba diving: This should be avoided throughout pregnancy due to potential risks to fetal circulation.
- Exercises performed in a supine position: After the first trimester, lying flat on your back for extended periods can compress major blood vessels, potentially reducing blood flow.
- High-impact activities or those requiring excessive jumping or bouncing: As pregnancy progresses, these may become uncomfortable and increase stress on joints.
Have a question about a specific type of exercise in pregnancy? Ask Obi! We have safety profiles for many different types of exercise in pregnancy and postpartum.
What About Weight Training?
Weight training can be a valuable component of a prenatal exercise routine, offering benefits like improved muscle tone, posture support, and preparation for the physical demands of later pregnancy and childbirth.
Safety Guidelines for Prenatal Weight Training
- Start with lighter weights: Studies suggest using free weights or machines with low weights (generally ≤10 pounds or 4.5 kg) with multiple repetitions through a full range of motion is both safe and effective.
- Focus on proper technique: Maintaining good form becomes even more important during pregnancy to avoid injury as joints and ligaments become more relaxed due to hormonal changes.
- Avoid the Valsalva maneuver: Holding your breath while lifting (the Valsalva maneuver) can temporarily increase blood pressure and intra-abdominal pressure, potentially affecting uteroplacental blood flow. Instead, exhale during exertion.
- Consider seated or supported positions: As pregnancy progresses, exercises may need to be modified to accommodate your changing center of gravity and to reduce fall risk.
- Listen to your body: If a particular movement feels uncomfortable or causes pain, modify or skip it.
Beneficial Weight Training Exercises
- Supported squats: These strengthen the lower body, which can help prepare for labor and delivery.
- Modified rows: Using resistance bands or light weights can help maintain upper body strength and counteract the forward pull of growing breasts.
- Seated shoulder presses: These help strengthen the upper body while providing stability.
- Wall push-ups or incline push-ups: These modifications allow continued upper body strengthening with reduced pressure on the abdomen.
- Pelvic floor exercises: While not traditional weight training, these can be incorporated into strength routines to support the increasing weight of the uterus.
Research on heavy resistance training during pregnancy is limited, but one small study of women experienced with resistance training found that high-intensity resistance exercises were well tolerated by both mother and fetus, even when using the Valsalva maneuver. Nevertheless, a cautious approach is recommended for most pregnant individuals.
Important Safety Considerations
When to Consult Healthcare Providers
Before beginning or continuing an exercise program during pregnancy, consult with your healthcare provider, especially if you:
- Have a history of preterm labor or certain medical conditions
- Are carrying multiples
- Have pregnancy complications like placenta previa or preeclampsia
- Experience any concerning symptoms during exercise
Warning Signs to Stop Exercising
Stop exercising and contact your healthcare provider if you experience:
- Vaginal bleeding
- Regular painful contractions
- Amniotic fluid leakage
- Shortness of breath before exercising
- Dizziness or feeling faint
- Headache
- Chest pain
- Muscle weakness affecting balance
- Calf pain or swelling
Practical Tips for Safe Exercise
- Stay hydrated: Drink water before, during, and after exercise.
- Wear appropriate clothing: Choose comfortable, breathable fabrics and supportive footwear.
- Warm up and cool down: Take time for gentle stretching and gradual transitions.
- Listen to your body: Pregnancy is not the time to push limits or achieve personal records.
- Modify as needed: As your pregnancy progresses, adapt exercises to accommodate your changing body.
- Exercise in a temperature-controlled environment: Avoid exercising in extreme heat or humidity.
Special Considerations for Athletes
Athletes who were highly active before pregnancy may be able to continue more strenuous training under medical supervision. Studies suggest that aerobic fitness typically remains the same or slightly improves during pregnancy if exercise is continued.
For elite or competitive athletes:
- Decreasing intensity may be necessary as pregnancy progresses
- Performance may naturally decline due to weight gain, physiologic anemia, edema, and musculoskeletal changes
- Recovery time between intense workouts should be extended
- Monitoring for signs of overtraining is important
A small study of Olympic-level athletes found that when exercising at ≥90% of maximal heart rate, some experienced temporary reductions in uterine artery blood flow. While these changes normalized quickly after exercise stopped, this suggests that extremely high-intensity exercise should be approached cautiously and with medical monitoring.
Final Thoughts
Exercise during pregnancy, when approached thoughtfully and with appropriate medical guidance, offers substantial benefits with minimal risks. By choosing suitable activities, monitoring intensity, and listening to your body, you can maintain fitness throughout pregnancy and support a healthy start for both you and your baby.
Whether you’re continuing a previous exercise routine, modifying your weight training program,, or starting a new gentle exercise regimen, the key is consistency and appropriate adaptation as your pregnancy progresses.
Remember that each pregnancy is unique. What works for one person may not be appropriate for another, so always personalize your exercise goals and activities in consultation with your healthcare provider.
Sources
American College of Obstetricians and Gynecologists. Physical Activity and Exercise During Pregnancy and the Postpartum Period. ACOG Committee Opinion No. 804. Obstetrics & Gynecology. 2020.
U.S. Department of Health and Human Services. Physical Activity Guidelines for Americans, 2nd edition. 2018.
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Davenport MH, Ruchat SM, Poitras VJ, et al. Prenatal exercise for the prevention of gestational diabetes mellitus and hypertensive disorders of pregnancy: a systematic review and meta-analysis. British Journal of Sports Medicine. 2018.
Davenport MH, Kathol AJ, Mottola MF, et al. Prenatal exercise is not associated with fetal mortality: a systematic review and meta-analysis. British Journal of Sports Medicine. 2019.
Beetham KS, Giles C, Noetel M, et al. The effects of vigorous intensity exercise in the third trimester of pregnancy: a systematic review and meta-analysis. BMC Pregnancy and Childbirth. 2019.
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Dipietro L, Evenson KR, Bloodgood B, et al. Benefits of Physical Activity during Pregnancy and Postpartum: An Umbrella Review. Medicine & Science in Sports & Exercise. 2019.
Ribeiro MM, Andrade A, Nunes I. Physical exercise in pregnancy: benefits, risks and prescription. Journal of Perinatal Medicine. 2022.