Safe and effective exercise during pregnancy: a trimester-by-trimester guide

Feeling unsure what “safe” looks like for prenatal fitness? You’re not alone—and the good news is that most pregnancies benefit from regular, moderate movement that’s adapted to your changing body.

Below is a practical, trimester-by-trimester plan for safe pregnancy workouts, plus key benefits and the warning signs to stop.

How much exercise during pregnancy is safe?

Most health organizations recommend 150 minutes of moderate-intensity aerobic activity per week during pregnancy, ideally spread across several days. The American College of Obstetricians and Gynecologists (ACOG) specifically endorses this amount as beneficial for most pregnant women.

If you weren’t physically active before pregnancy, don’t worry about hitting those numbers immediately. UC Davis Health experts suggest starting small with just 10-15 minutes of walking several times a week, then gradually building up your endurance.

As for intensity, the Better Health Channel recommends working at less than 75% of your maximum heart rate. More practically, use the “talk test”—you should be able to hold a conversation while exercising without becoming breathless.

Benefits of staying active

Regular prenatal fitness offers numerous advantages for both you and your baby. Consistent moderate exercise improves cardiovascular health, elevates mood, and reduces stress levels. It also helps manage weight gain and supports better sleep quality—something many pregnant women struggle with.

Physical activity can significantly reduce common pregnancy discomforts like back pain and constipation. Perhaps most importantly, staying active during pregnancy has been linked to lower risk of gestational diabetes and hypertensive disorders, while building stamina that supports labor and postpartum recovery.

The ACOG’s overview of pregnancy exercise provides more detailed information on these benefits and relevant safety considerations.

Safe workout types for pregnancy

Low-impact cardio

Walking provides a total body workout that’s gentle on your joints and muscles. Swimming and water aerobics are especially beneficial as the water supports your weight while engaging multiple muscle groups. If you were a runner before pregnancy, light jogging may continue to be appropriate. Stationary cycling offers cardiovascular benefits with minimal fall risk, making it safer than road cycling as your balance changes during pregnancy.

Strength training

Light to moderate resistance training remains beneficial throughout pregnancy. Focus on using lighter weights with higher repetitions rather than attempting maximal lifts. The Better Health Channel advises avoiding heavy weights and never exercising to the point of exhaustion. Also, avoid holding your breath during exertion (Valsalva maneuver).

Mobility and core

Modified prenatal yoga and Pilates can maintain flexibility and core strength when properly adapted for pregnancy. Daily gentle stretching helps relieve tension, while pelvic floor exercises prepare these crucial muscles for delivery and recovery. According to ACOG, these classes should avoid poses requiring lying on your back for extended periods, particularly after the first trimester.

Trimester-by-trimester guide

First trimester (weeks 1–13): build consistency and listen to energy levels

The initial weeks of pregnancy often bring fatigue and nausea, making exercise feel challenging. Your primary goals should be maintaining or establishing a routine while managing your changing energy levels.

Aim for 20–30 minutes of moderate cardio three to five days per week. Walking, swimming, and stationary biking are excellent options that can be easily adjusted based on how you feel. Complement this with two or three short strength sessions weekly, focusing on whole-body movements like squats, rows, and presses using light weights.

This is also an ideal time to begin gentle core activation and pelvic floor engagement exercises, which will support your changing body throughout pregnancy.

Don’t hesitate to shorten sessions on low-energy days—consistency matters more than intensity. The Better Health Channel emphasizes avoiding overheating and heavy sweating, so exercise in cool environments and stay well-hydrated.

Second trimester (weeks 14–27): strengthen and support posture

Many women experience an energy boost during the second trimester as morning sickness subsides. This period is ideal for maintaining your aerobic base while supporting your changing posture and core.

Continue with 30-minute moderate cardio sessions most days, choosing from brisk walking, swimming, or easy jogging if you were a runner previously. Incorporate strength training two to three times weekly, with special emphasis on back, glute, and leg exercises to support your changing center of gravity. Use light-to-moderate loads with controlled movements.

Adding prenatal yoga or Pilates once or twice weekly can improve hip mobility and thoracic rotation, which become increasingly important as your belly grows. After the first trimester, ACOG recommends avoiding exercises that require lying flat on your back for extended periods; opt for side-lying or inclined positions instead.

As your pregnancy progresses, you may need to widen your stance for squats, but only do so if comfortable. Healthline advises avoiding positions that strain the pubic symphysis if you notice pain in this area.

Third trimester (weeks 28–40+): move for comfort, mobility, and birth prep

During the final trimester, focus shifts to maintaining mobility, circulation, and gentle strength while managing increasing discomfort. Your growing belly significantly changes your center of gravity, requiring further exercise modifications.

Continue with low-impact cardio like walking and swimming most days, but consider shorter, more frequent sessions if fatigue increases. Prenatal yoga or Pilates with props for support becomes especially valuable now, as does daily pelvic floor work in preparation for delivery.

Functional bodyweight movements—supported squats, wall push-ups, hip hinges, and heel raises—help maintain strength without requiring equipment or complex positions. As Healthline suggests, keep your feet closer than hip-width if you experience pubic symphysis pain, avoiding wide or asymmetrical stances.

The third trimester is also when fall risk increases due to your shifting center of gravity. ACOG recommends avoiding activities with high fall potential, such as switching from road cycling to a stationary bike if you haven’t already.

Safety checklist for every workout

Before beginning any workout, warm up for at least five minutes to prepare your muscles and joints. UC Davis Health emphasizes this preparation, as well as cooling down with gentle stretching afterward.

Hydration becomes even more crucial during pregnancy, so drink water before, during, and after exercise. The Better Health Channel advises reducing intensity in hot or humid conditions to prevent overheating.

Maintain a conversational pace throughout your workout—if you can’t talk while exercising, you’re pushing too hard. Similarly, favor lighter weights with higher repetitions rather than maximal lifting efforts that could strain your body.

If you were already a regular runner or racquet-sport athlete before pregnancy, ACOG notes you may continue these activities with your healthcare provider’s guidance and appropriate modifications as your pregnancy progresses.

Warning signs to stop exercise and call your clinician

While exercise is generally beneficial during pregnancy, certain symptoms warrant immediate cessation of activity and medical consultation. Stop exercising and contact your OB/GYN or midwife if you experience vaginal bleeding or fluid leakage, dizziness, fainting, chest pain, or severe headache.

Other concerning symptoms include shortness of breath before exertion, painful uterine contractions or regular tightening, calf pain or swelling, and any marked decrease in fetal movement. These could indicate potentially serious conditions requiring prompt medical attention.

For comprehensive safety information, review ACOG’s full guidance on exercise during pregnancy.

Sample weekly plan for prenatal fitness

A balanced prenatal fitness routine might include three 20-30 minute brisk walks, two light full-body strength sessions (focusing on squats, rows, deadlifts with light weights or bands, presses, and carries), one swimming or stationary biking session, and two short mobility or yoga sessions.

Additionally, incorporate two to three sets of pelvic floor contractions with relaxed breathing daily. This variety provides comprehensive fitness benefits while allowing flexibility to adjust duration and intensity based on your trimester and daily energy levels.

How Beginning.com can support your prenatal routine

Staying active is easier with tools that meet you where you are. The Beginning.com app offers 3D sound journeys to reduce stress, ease discomfort, and improve sleep on rest days or recovery nights. With over 100 masterclasses across mind, body, and soul, you can build sustainable habits that support your pregnancy journey.

The app’s personalized cycle and symptom tracker helps you log energy, mood, and movement patterns, allowing you to adapt your exercise plan week by week. The Inspirational Feed delivers evidence-based tips tailored to your specific interests and pregnancy stage.

Remember: the best prenatal fitness plan is one you can stick to. Keep it moderate, listen to your body, and use small, steady steps to stay active throughout every trimester.