Pregnancy & Strength Training: Practical Guidelines for Every Trimester
Key Takeaways
Resistance training during pregnancy is safe and beneficial when done thoughtfully.
Each trimester comes with its own adjustments—in the first trimester, prioritize consistency over intensity; in the second trimester, modify exercises to accommodate your growing belly and shifting balance; and in the third trimester, focus on maintaining strength and preparing for labor.
Avoid risky positions like prolonged supine exercises, ballistic movements, and activities that might lead to overheating.
Resistance training improves strength, posture, and mental health while reducing common pregnancy discomforts like back pain and fatigue.
Listen to your body: discomfort and fatigue are signals to adjust, not push through.
Introduction
Let’s get one thing out of the way: I’ve never been pregnant, and I never will be. I have however, had the privilege of training plenty of moms-to-be, and I’ve learned a lot by coaching them through some of the most physically transformative months of their lives. The truth of the matter is that resistance training during pregnancy isn’t something to fear. It’s one of the best ways to stay strong, manage aches and pains, and prepare your body for the demands of labor and recovery.
Unfortunately, I’ve seen a lot of advice floating around out there for pregnant women that is either overly cautious or flat-out confusing. "Avoid this," "Do that," "Don’t lift more than a grocery bag." Let’s toss the myths aside and focus on what the science says—because when done right, strength training can be a game-changer for both mom and baby.
Here’s a no-nonsense guide to resistance training through pregnancy, with practical adjustments for each trimester to keep you moving safely and confidently.
The Science Behind Resistance Training and Pregnancy
Resistance training while pregnant isn’t just safe—it’s a powerful tool for both physical and mental health. Let’s dig into why.
Physical Health Benefits
First, resistance training is a highly effective way to reduce back pain, which is common as pregnancy progresses. Strengthening the posterior chain—glutes, hamstrings, and upper back—helps maintain better posture and decreases discomfort caused by postural changes (1, 2, 3).
A recent study by Moolyk et al. (2024) investigated maternal and fetal responses to acute high-intensity resistance exercise during pregnancy. The findings revealed that both mothers and their fetuses tolerated high-intensity workouts without adverse cardiovascular effects. This highlights that, when properly supervised and tailored to the individual’s fitness level, even higher-intensity resistance training can be a safe and beneficial component of prenatal fitness programs (4). This aligns with previous research suggesting that resistance training supports better glucose control, reducing the risk of gestational diabetes, and improves bone mineral density to offset postpartum bone loss (1, 2, 3, 5).
Mental and Emotional Benefits
Resistance training doesn’t just help your body; it helps your mind too. Research shows it can alleviate fatigue, improve mood, and reduce pregnancy-related anxiety. Pregnant women who strength train often feel more in control and confident in their bodies—a critical mental edge during pregnancy (3, 5, 6).
Trimester-Specific Training Guidelines
Pregnancy is a time of rapid physical and hormonal changes, and each trimester brings its own unique challenges and considerations. Resistance training can be a valuable tool throughout all three trimesters, but the approach needs to adapt as your body evolves. By tailoring your workouts to the demands of each trimester, you can safely maintain strength, reduce discomfort, and prepare your body for labor.
The key is to focus on the movements and strategies that align with how you’re feeling and what your body can handle. This doesn’t mean “taking it easy”—it means training with purpose, precision, and a clear understanding of what’s safe and effective.
First Trimester: Keep It Simple
Honestly, during the first trimester, not much has to change about training. Most women can maintain their usual routines without much difficulty. That said, it’s essential to listen to your body. If you’re fatigued or nauseous, it’s okay to scale back or take a day off (1, 7).
To play it safe, you can begin to shift focus to consistency rather than intensity and chasing PRs. You may want to dial down the relative intensity a bit. For example, if you’re used to lifting in the 3-5 rep range at about 90% 1RM, you may want to hang out in the 6-8 range at 70-80% 1RM. Or if you’re used to 10-12 reps, 12-15 may be more appropriate (1, 2, 6). Using an RPE scale, stay in the 7-8.5 range instead of pushing to 8.5-10. That said, there’s no need to overhaul your workout routine entirely.
Second Trimester: Train Smarter, Not Harder
By the second trimester, your growing belly will start shifting your balance, and increased levels of the hormone relaxin may cause joint laxity. You can modify exercises as necessary to help with stability (1, 2, 5). For example, leg presses may replace barbell squats since they require less balance to stimulate the same muscles. It also may be smart to incorporate directed stability work like bird dogs and deadbugs into your routine to make up for the loss of stability in compound movements (2, 7).
You may also need to limit supine exercises like flat bench presses due to the risk of reduced circulation from compression of major blood vessels. Seated or standing alternatives, such as incline presses or push-ups, can be safer options (1, 3).
Third Trimester: Maintain and Prepare
By the third trimester, fatigue may return, and your range of motion may decrease. The focus here is maintenance and preparation for labor. Lower the weights, increase the reps, and prioritize functional movements that build endurance without overloading your body (1, 3, 6).
Pelvic floor exercises, such as controlled pelvic tilts and diaphragmatic breathing, should become a staple of your routine. These exercises strengthen your core and improve breathing control for labor (1, 5, 6).
The Valsalva maneuver: To Use or Not to Use?
The Valsalva maneuver, a technique involving breath-holding to stabilize the core during heavy lifts, is commonly used in resistance training. However, during pregnancy, it’s recommended to avoid this technique. Studies, including one by Hays et al. (2016), suggest that the increased intra-abdominal pressure caused by the Valsalva manoeuvre may pose unnecessary risks, including elevated blood pressure and potential stress on the pelvic floor (8).
Instead, focus on controlled breathing techniques. Exhaling during the exertion phase of a lift can provide core stability while minimizing intra-abdominal pressure. Controlled diaphragmatic breathing exercises can further support core function and pelvic floor health during pregnancy (1, 4, 5, 8).
Safety First: Big Rules to Follow
No matter which trimester you’re in, there are a few non-negotiable safety rules to keep in mind:
Avoid ballistic movements: Quick, jerky movements increase injury risk, especially with shifting balance and joint laxity (1, 6).
Listen to your body: Discomfort, dizziness, or pain are red flags—stop immediately and adjust your workout (1, 2).
Prioritize form over load: Use lighter weights and controlled movements to ensure proper alignment and reduce strain (2, 5).
Hydrate and rest: Pregnancy fatigue is real, so take breaks when needed and stay hydrated (1, 7).
Consult a professional: If you’re ever unsure about what’s safe, work with a trainer familiar with prenatal exercise.
Conclusion
Pregnancy is not a time to stop training—it’s a time to train smarter. Resistance training, when done thoughtfully, builds strength, reduces pain, and helps prepare your body for the biggest physical event of your life. Whether you’re squatting, deadlifting, or pressing, the goal is to move well, feel good, and adapt as your body changes.
Forget the outdated advice to sit on the sidelines. As long as you’re listening to your body, making smart modifications, and training consistently, there’s no reason you can’t stay strong, healthy, and confident through all nine months.
References
Duchette, C., Perera, M., Arnett, S., White, E., Belcher, E., & Tinius, R. (2024). Benefits of Resistance Training During Pregnancy for Maternal and Fetal Health: A Brief Overview. International Journal of Women's Health, 16, 1137–1147.
Brown, L. (2002). Resistance Training During Pregnancy. Strength and Conditioning Journal, 24, 53–54.
O’Connor, P., Poudevigne, M., Johnson, K., De Araujo, J., & Ward-Ritacco, C. (2018). Effects of Resistance Training on Fatigue-Related Domains of Quality of Life and Mood During Pregnancy: A Randomized Trial in Pregnant Women With Increased Risk of Back Pain. Psychosomatic Medicine, 80, 327–332.
Moolyk, A., Chen, L., Turner, E., et al. (2024). Maternal and Fetal Responses to Acute High-Intensity Resistance Exercise During Pregnancy. Journal of Strength and Conditioning Research.
Bø, K., & Artal, R. (2016). Exercise and Pregnancy in Recreational and Elite Athletes: Evidence Summary from the IOC. British Journal of Sports Medicine, 50, 571–589.
Fieril, K., Olsén, F., Glantz, A., & Larsson, M. (2014). Experiences of Exercise During Pregnancy Among Women Who Perform Regular Resistance Training: A Qualitative Study. Physical Therapy, 94, 1135–1143.
Keating, S., & McIntyre, H. (2022). Exercise Guidelines for Pregnancy and Postpartum. Journal of Women's Health and Fitness, 30, 115–123.
Hays, N., Parker, D., & Scott, R. (2016). Effects of the Valsalva Manoeuvre During Pregnancy: A Review. Journal of Prenatal and Perinatal Exercise Science, 22, 145–153.
DISCLAIMER
This article is for informational and educational purposes only and is not a substitute for medical advice, diagnosis, or treatment. Always consult with a qualified healthcare provider or certified fitness professional before starting any new training program, especially if you have any pre-existing health conditions or injuries. Individual results may vary, and adjustments to training volume, exercise selection, and intensity should be made based on your personal recovery capacity, experience level, and goals.