Why Your Pre-Baby Workouts Won't Work After Pregnancy (Postpartum Fitness Explained)

Spoiler alert: If you’re months—or even years—postpartum and wondering why that old group fitness class you used to love isn’t getting you the results it used to, you’re not imagining it. Your body has changed in big ways, and your fitness approach should too. In fact if your fitness approach doesn't change, you're likely to end up with the same back pain, leakage and core weakness when your grandkids roll around - these problems don't just go away with time, you need to address them with the strategies below to fix them!

In this post, we’ll break down why your pre-baby workouts might be holding you back, what’s happening under the surface, and how to safely rebuild strength with a postpartum fitness plan that actually works.

Your Postpartum Body Isn’t the Same as Your 20s Body

Before pregnancy, workouts like bootcamps, HIIT, running, or intense core routines may have made you feel strong, lean, and energized. But after having a baby—whether vaginally or via C-section—your body’s alignment, core function, and muscle coordination go through massive changes.

Here’s what pregnancy does to your core and postural alignment:

1. Your Core Muscles Stretch and Separate

As your belly grows, your rectus abdominis (your “six-pack” muscles) stretch apart to make room for your baby. This separation is called diastasis recti, and it weakens your ability to create tension through the front of your core. Even postpartum, this gap may remain if not intentionally rehabbed.

2. Your Pelvis Tilts and Your Ribs Flare

To balance the growing baby bump, your body often shifts into an anterior pelvic tilt—think of your pelvis tipping forward and your low back arching. At the same time, your ribs often flare outward, pulling your diaphragm and core out of alignment. This misalignment disrupts how your deep core and pelvic floor work together.

3. Your Breathing Mechanics Change

With the diaphragm pushed up by your uterus, your breathing becomes more shallow and chest-based. This limits your ability to engage the deep core muscles and pelvic floor through breath—an essential part of functional core strength.

4. Ligaments Loosen and Stability Decreases

Hormones like relaxin and progesterone soften your joints and connective tissue to prepare for birth—but they also make it harder to stabilize your spine, hips, and pelvis during movement. This instability often lingers into the postpartum period.

So postpartum as you're attempting to do a spin class, go on a run, or burn off every calorie you ate the day before....

Four major reasons why your old workouts are more likely to HURT your progress rather than HELP it 👇🏼

1. You don't have the time you used to. Girl, you don't even pee by yourself anymore. Aiming to get in an hour long workout likely isn't realistic for your new life as a mom. Your new workout routine needs to be reflective of your new life. Let's stop trying to fit a square peg in a round hole!

   
   

2. You don't have the energy you used to.  Sleep deprivation, mental load, and the responsibility of keeping a tiny person alive affect how your body handles stress—including exercise. High-intensity training can actually raise cortisol and increase fatigue or injury risk.

   
   

3. Your core needs to BUILD back, not BOUNCE back. Even years postpartum, many women still experience diastasis recti, pelvic floor dysfunction, or poor core coordination that can’t be fixed by crunches or planks. In addition, incorporating intense sweaty workouts too soon can contribute to core dysfunction.

   
   

4. Your hormones are still shifting. Relaxin, a hormone that loosens joints and ligaments during pregnancy, can linger and impact your stability and joint support—especially if you're still breastfeeding.

   
   

So What Does Work Postpartum? Working Smarter not Harder 👏🏼

Your body deserves a smarter, gentler, and more effective approach to getting strong again. Here’s how to do it:

1. Start with Breath work & Core Reconnection

Your deep core includes the diaphragm, pelvic floor, transverse abdominis, and multifidus. Learning how to breathe properly (like 360° breathing) and activate these muscles is the first step in postpartum core rehab. My FREE Postpartum Core Guide will show you how.

2. Focus on Functional Movements

Movements like squats, lunges, bridges, dead bugs, and farmer's carries—when done with proper form—help retrain your nervous system and rebuild core stability from the inside out.

3. Progress Slowly and Strategically

Don’t rush to “bounce back.” Instead think about "building back". Gradually reintroduce load and intensity based on how your body feels—not what some fit-fluencer workout app says.

4. Listen to Your Symptoms

Pain, leaking, coning/doming, or pressure are signs your body isn’t ready for that movement yet. These symptoms are data—not failures. Scale it back and again, focus on BUILDING 💪🏼.

You Deserve More Than “Just Get Back to the Gym”

Postpartum fitness isn’t about bouncing back. It’s about rebuilding a foundation that supports you in motherhood and beyond—without pain, leaks, or feeling like your core is always “off.”

If your old workouts aren’t cutting it, it’s not your fault—and it’s not about willpower, lacking motivation or being lazy. You need a plan that respects what your body’s been through 🫶🏼.

Ready to Take the Guesswork Out of your Postpartum Fitness + Rebuild Core Strength the Right Way?

If you’re ready to feel strong, stable, and confident again—without guessing your way through postpartum recovery—I’ve got you covered 👯💪🏼❤️😘

👉 Click here to read more or get started with 1:1 coaching

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