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Why Strength Training is Critical During Pregnancy

Physical activity during pregnancy has a myriad of benefits (for you and your little one). In this piece, we’d like to discuss the specific benefits of strength training and why it is such a critical component of any prenatal exercise routine.

Strength training not only helps you mitigate common pregnancy pains — like low back pain, SI joint pain, diastasis recti, and pelvic floor dysfunctionbut it also enables you to better handle the stresses of childbirth. In fact, one large study showed the following results from weight-bearing exercise performed throughout pregnancy (Clapp, 1998):

  • 75% reduction in maternal exhaustion
  • 75% reduction in need for forceps or C-section
  • 50% decrease in need for oxytocin
  • 50% decrease in need for medical intervention due to fetal heart-rate abnormalities
  • 30% reduction in the duration of the active labor phase

Despite these benefits, we often hear guidance to limit physical exertion when strength training in order to minimize stress to the body. Pregnant people are often advised to “reduce loads” or focus on bodyweight exercise only. However, this article reveals the issues with this guidance and discusses what we believe to be a safer and much more effective approach.

Why “Limiting Stress” is Less Effective

The guidance to limit stress to the body is often given to mitigate potential pains & injuries that could arise from the increased stress that is placed on the body during pregnancy. While mitigating pain & injury should be a critical goal of any prenatal training program, the graph below illustrates how the “low stress approach” is not the most effective strategy to achieve this goal. In fact, it could even increase the risk of pains & injuries.

This “strength-to-weight” graph below shows the following:

  • Horizontal axis tracks the duration of pregnancy (in months) from conception to birth
  • Vertical axis tracks weight in pounds
  • Pink line illustrates an individual’s weight in pounds
  • Blue line illustrates the weight an individual can lift (in pounds)

NOTE: The actual numbers on the vertical axis are not important. The trend is what’s important.

Strength-to-Weight Trend

Looking at the pink line above, this graph shows an example of an individual who begins pregnancy at 120 lbs and ends pregnancy at 150 lbs.

Looking at the blue line above, the “100” at the start of pregnancy might refer to this individual being able to deadlift 100 lbs. Again, the specific numbers are not important. If this person follows the conventional wisdom of “reducing loads” to limit stress, then strength will consequently decrease. This is because muscles need to be “stressed” in order to adapt and grow stronger to tolerate greater levels of stress. This is the purpose of strength training.

The trend that is important to note is the divergence of the pink and blue lines by the end of pregnancy. Following the “low stress” approach can leave you being weakest when at your heaviest, which could result in pain, discomfort, or even injury.

Think about it, the healthy weight gain guidelines for a single pregnancy and normal BMI is between 25 – 35 lbs, and 47% of people gain more than this (Deputy et al, 2015). That’s a lot of additional weight to carry around (not to mention the other physical and physiological stresses that pregnancy brings). By “stressing” your muscles via moderate to higher-intensity loads, your muscles will adapt to handle the greater “load” of pregnancy weight gain. This results in fewer pains, easier movement, and more energy (because your body doesn’t have to work as hard to manage the added weight).

The First Step to Effective Strength Training

While the illustration above might help you appreciate the benefits of a “higher-intensity” approach, it is important to go about this in the safest and most effective way so that you can reap all the benefits of strength training while mitigating the risk of pain or injury. This means that — prior to adding load — it is imperative to first establish a solid foundation upon which to build. This means mastering the fundamentals of neutral alignment, deep core activation, and proper movement mechanics.

We have developed a 3-stage Prenatal Training Framework (pictured below), with each stage consisting of certain objectives or skills that you master. As you can see, the first (important) stage is Foundation, where we work on mastering many of the fundamentals mentioned above — prior to progressing to the Strength Stage.

We’ve created a variety of resources to help you implement the fundamentals of this framework and train safely and effectively during pregnancy:

  • The Guide to Prenatal Exercise: This self-paced online course empowers you with all the education & resources you need to prepare your body for an easier pregnancy, smoother delivery, & faster recovery. Learn how to adapt an existing fitness routine, or how to plan your own workouts using the workout builder included.
  • Self-Guided Training ProgramsGet a done-for-you training program tailored to your stage. You’ll receive 3 total body workouts per week – delivered via the ProNatal Fitness app– that progress you through the training stages above in a manner that’s right for you based on your stage when starting.
  • Find a Coach: Looking for an expert personal trainer to design, and take you through, a customized training program? We’ve got you covered. You can choose to work with one of our ProNatal Personal Trainers virtually or find a ProNatal Certified Coach near you.

Are you a Health & Fitness Professional?

If you are a health & fitness professional interested in learning more about coaching pre & postnatal clients, explore our Pre & Postnatal Professional EducationWe offer in-depth education to become ProNatal Certified for those looking to specialize in training this population, and a Mini Course for GroupX instructors who just need the basics.


Clapp, J. F., Ill. (1998). Exercising Through Your Pregnancy. Champaign, Ill. Human Kinetics.

Deputy, N., Kim, S., Sharma, A. (2015). “Gestational Weight Gain – United States 2012 and 2013.” Centers for Disease Control and Prevention.