How to Modify Your Workouts During Pregnancy

Staying active during pregnancy offers numerous benefits for both you and your baby, from improved mood and energy levels to better sleep and reduced discomfort. Regular exercise can help prepare your body for labor and delivery while supporting your changing physique, but knowing how to modify your workouts safely is essential for a healthy pregnancy journey.

Key Highlights

Here’s what you need to know about exercising safely throughout your pregnancy:

• Aim for 150 minutes of moderate-intensity activity spread throughout the week
• Listen to your body and adjust intensity using the talk test rather than heart rate
• Avoid exercises that require lying flat on your back after 16 weeks
• Focus on low-impact activities and proper form as your center of gravity shifts
• Stop exercising and contact your healthcare provider if you experience dizziness, pain, bleeding, or contractions

Understanding Changes: Safety Guidelines

Before beginning or continuing any exercise routine during pregnancy, consulting with your healthcare provider is essential. They can offer personalized guidance based on your health history and pregnancy progression, ensuring your workout plan is appropriate for your specific situation. The American College of Obstetricians and Gynecologists (ACOG) recommends 150 minutes of moderate-intensity aerobic activity weekly, ideally spread across multiple days.

Rather than monitoring heart rate, which fluctuates naturally during pregnancy, focus on the Rate of Perceived Exertion (RPE) and the talk test. You should be able to maintain a conversation while exercising—if you’re too breathless to speak, it’s time to reduce the intensity. This self-monitoring approach is more reliable than outdated heart rate guidelines and helps you stay within safe exercise zones as your body changes.

Understanding Changes: Trimester-Specific Modifications

During the first trimester, many women can continue their pre-pregnancy exercise routines with minimal adjustments if they were already active. However, listen to your body carefully, as fatigue and nausea may require reducing workout duration or intensity. Stay well-hydrated and avoid overheating, particularly in the first trimester when your baby’s organs are developing.

The second trimester brings significant anatomical changes requiring more substantial workout modifications. After 16 weeks, avoid exercises that require lying flat on your back, as the growing uterus can compress major blood vessels, potentially reducing blood flow to you and your baby. Instead, modify these exercises by elevating your upper body with pillows or switching to inclined or side-lying positions. Core workouts should be adapted to accommodate your growing belly, focusing on functional movements rather than traditional crunches or sit-ups.

Your Body & Baby: Adapting Different Exercise Types

Cardio activities can be maintained throughout pregnancy with appropriate modifications. Walking, swimming, stationary cycling, and low-impact aerobics are excellent options as they support your weight and minimize joint stress. If you experience pregnancy headaches during the 2nd trimester, consider gentler activities like prenatal yoga or swimming, which may help alleviate discomfort while keeping you active.

Strength training remains beneficial during pregnancy but requires thoughtful adjustments. Reduce weights by 20-30% from your pre-pregnancy routine and increase repetitions to maintain muscle tone without straining. Focus on proper form over heavy resistance, especially as your center of gravity shifts in later months. Pelvic floor exercises, like Kegels, are particularly valuable throughout pregnancy and can be done discreetly anywhere, preparing these muscles for delivery and postpartum recovery.

Your Body & Baby: Balance and Posture

As your pregnancy progresses, your changing body weight and center of gravity affect your balance and posture. By the 2nd month pregnancy onward, hormonal changes begin loosening your ligaments and joints, increasing the risk of injury during certain movements. Avoid activities with a high risk of falling, such as skiing, horseback riding, or high-intensity plyometric exercises.

When strength training, use supported positions whenever possible—seated exercises, wall support, or stability balls can provide added safety. For yoga or stretching, modify poses that challenge balance, using props like chairs or walls for support. Pay special attention to your posture during all activities, focusing on neutral spine positioning to reduce lower back strain. This becomes increasingly important as your baby grows and places more demand on your core and back muscles.

Healthy Living Tips: Warning Signs and Precautions

While exercise is beneficial, knowing when to stop is crucial for your safety and your baby’s well-being. Be alert to warning signs that indicate you should end your workout and contact your healthcare provider immediately. These include vaginal bleeding, dizziness or lightheadedness, chest pain or heart palpitations, shortness of breath before exertion, and headache accompanied by visual disturbances.

Additional reasons to stop exercising include muscle weakness, calf pain or swelling, regular painful contractions, fluid leaking from the vagina, or decreased fetal movement after exercise. These symptoms could signal potential complications that require medical attention. Remember that pregnancy is not the time to push through discomfort—always prioritize safety over fitness goals.

Healthy Living Tips: Activities to Avoid

Certain activities should be avoided entirely during pregnancy due to increased risks. Contact sports (basketball, soccer, hockey) carry a risk of abdominal trauma, while activities with a high fall risk (downhill skiing, horseback riding, gymnastics) become increasingly dangerous as your balance changes. Hot yoga and hot Pilates should be avoided due to the risk of overheating, which can affect fetal development.

Staying properly hydrated is essential during pregnancy workouts, as dehydration can contribute to overheating and reduced blood flow. Drink water before, during, and after exercise, and consider extending your warm-up and cool-down periods to allow for gradual transitions in activity levels. Pay attention to environmental conditions as well—exercising in excessive heat or humidity increases your risk of overheating and dehydration.

Staying Active Safely Throughout Pregnancy

Exercise during pregnancy isn’t about maintaining pre-pregnancy fitness levels or achieving personal bests—it’s about supporting your changing body and preparing for labor and delivery. By making thoughtful modifications to your workouts based on trimester-specific needs, you can stay active safely while honoring your body’s incredible work of growing your baby. Remember that even mild to moderate activity provides significant benefits, and listening to your body’s signals is the most important guide for your pregnancy fitness journey.

Sources

American College of Obstetricians and Gynecologists: Exercise During Pregnancy
Mayo Clinic: Pregnancy and Exercise
Physical Activity and Exercise During Pregnancy – NCBI
American Pregnancy Association: Exercise Guidelines During Pregnancy
CDC: Physical Activity During Pregnancy and Postpartum