The Incredible Shift
- Dominique Posillico
- Dec 23, 2025
- 5 min read
How Pregnancy Reshapes Your Body
Pregnancy brings an incredible amount of change to the body—some we can see, others we can feel. Each one plays a role in how we move, how we feel during workouts, and how we show up for ourselves day to day. While exercise may look different during this season, it doesn’t need to disappear. In most cases, movement can be safely continued by adjusting and modifying to support your ever-changing body.
We’ll take a look at some of the functional changes that happen during pregnancy. Keep in mind, these are just general points to guide you. Each trimester has its own unique changes and considerations, we’ll explore those in a future post.
Abdominal Adaptations During Pregnancy
A variety of adaptations occur in the abdomen to accommodate a growing baby. The core muscles, myofascial tissue, pelvic floor, and diaphragm all work together as an integrated system, and each undergoes changes throughout pregnancy. These shifts can lead to musculoskeletal imbalances and postural dysfunction. As the abdominal muscles stretch and weaken, the lower-back muscles often compensate by shortening and tightening. This creates an exaggerated arch in the low back—known as lordosis—that typically becomes more pronounced as the baby grows. It is also common to experience diastasis recti, or separation of the abdominal muscles. While this cannot always be avoided, engaging in appropriate, safe exercises can help minimize the split and support core function. With the back under constant tension and the core stretched, it’s common to experience muscle fatigue and pain. Over time, these adaptations can also contribute to a decrease in overall power and strength. These physical changes don’t just affect the core—they also happen upward impacting the ribcage, breathing patterns, and the diaphragm’s ability to move efficiently.
Breathing Through the Changes
Changes occur throughout the body, not just in the abdomen. As pregnancy progresses, the ribcage begins to flare and the shoulders may round forward—known as kyphosis—largely due to increased breast size and weight. These postural shifts, combined with the growing baby, can restrict the diaphragm’s ability to move downward. As a result, the chest muscles are forced to overcompensate. Instead of the diaphragm pulling down while the ribcage expands, the smaller chest muscles lift the ribcage upward to assist with breathing. The thing is, these chest muscles are not designed for primary respiration—and because there is less space for the lungs to expand—breathing can become less efficient. This also creates more work when the postpartum journey beings, requiring better breathing habits to be re-established.
Despite these limitations, pregnant women should still aim to keep proper posture and breathe with the diaphragm. The diaphragm sits above the baby, and using it effectively not only improves oxygen exchange but also supports optimal baby positioning, pelvic floor function, and core engagement. Maintaining this connection acts as valuable prehab for postpartum recovery, as all of these systems are deeply interconnected. Together, these upper-body and respiratory changes further influence overall alignment and set the stage for the shifts in the body’s center of gravity that occur in pregnancy.
Your Body’s New “Center”
These anatomical changes affect more than just how the body looks and feels—they also influence how the body interacts with gravity. As posture shifts and weight distribution changes, the body’s center of gravity naturally moves forward. This shift makes maintaining balance increasingly challenging as both the baby and the abdomen grow. Over time, a pregnant person adapts to this constant state of change, no longer experiencing a consistent “normal” baseline within their own body.
Combined with a larger belly that limits visibility of the feet, as well as increased ligament laxity and decreased joint stability, these factors can significantly reduce balance and overall stability. The body must work harder to remain upright, coordinated, and steady during everyday movements.
Hormones Helping You Grow, Adapt, and Prepare
As previously mentioned, the body experiences increased ligament laxity during pregnancy to help the pelvis widen in preparation for birth. This laxity is driven primarily by the hormone relaxin. Because relaxin circulates through the bloodstream, its effects are not limited to the pelvis—ligaments, joints, tendons, cartilage, and even surrounding muscles throughout the entire body become more flexible and, consequently, less stable. Relaxin is only one of several hormones influencing the body during this time. Estrogen levels also rise significantly during pregnancy. There are three types of estrogen—estradiol (E2), estrone (E1), and estriol (E3). During pregnancy, estriol becomes the dominant form, and it plays a major role in supporting fetal growth and preparing the body for labor. This is just a glimpse at what hormones are at play here.
Levels of oxytocin, often called the “love hormone,” also rise during pregnancy. Beyond its emotional benefits, oxytocin heightens auditory sensitivity, helping the mother become more alert and responsive as birth and postpartum approach. Prolactin, the hormone responsible for milk production, increases during pregnancy and remains elevated postpartum. These hormones each have their own role, but together, oxytocin and prolactin contribute to lighter, more vigilant sleep, supporting the mother’s natural responsiveness to her baby. These hormones leave the mother more tired and weak when it comes to everyday life, inclusive of workouts.
These are just a few of the many hormonal shifts that occur throughout pregnancy—each one playing a unique role in supporting both the mother’s health and the developing connection between mother and baby. ach having their own implications when it comes to movement whether that be modifying movement to be less demanding and impactful to incorporating longer rest periods.
Embracing Your Changing Body
Pregnancy brings an incredible number of structural, postural, respiratory, and hormonal changes—each one influencing the way the body moves, breathes, and adapts. From the stretching of the abdominal wall and the development of lordosis and kyphosis, diaphragmatic restrictions, shifting center of gravity, and the changes that come with all the hormonal shifts, the body is constantly recalibrating to support the growing baby. These changes can affect strength, balance, stability, and overall coordination, but they are not a sign that movement should be avoided. In fact, they highlight why staying active is so important.
Continuing to move throughout pregnancy helps reduce the risk of injury, supports joint stability, and maintains balance as the center of gravity shifts. Practicing proper breathing mechanics can improve comfort, aid in baby positioning, and support pelvic floor and core function—essential components of both labor preparation and postpartum recovery. Keeping in mind the hormonal shifts helps to understanding these changes that aren't visible. Having a better overall understanding empowers you to modify your workouts, adjust your expectations, and train in ways that respect your body’s evolving needs.
While this is only a glimpse into the many adaptations that occur during pregnancy, keeping them in mind allows you to move with intention, confidence, and safety. Movement is not only safe—it’s one of the most supportive tools you have during this season of change. And if you’re pregnant or postpartum and unsure how to modify your workouts, what exercises are appropriate, or how to navigate these changes, I encourage you to book a consult call with me so we can create a plan that supports you every step of the way!
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