Why Am I So Flexible During Pregnancy? Understanding the Relaxin Hormone

What every pregnant woman needs to know about relaxin, joint stability, and safe exercise during pregnancy and postpartum

You’re a few months into pregnancy and suddenly you can touch your toes. You can fold deeper in yoga. Hip stretches that were always tight feel amazing. You think: “Finally! I’m getting flexible!”

But then your yoga teacher tells you to pull back. To go to only 80% of where you can go. To not push so deep into stretches.

And you think: “Wait, isn’t flexibility a good thing?”

Here’s what’s actually happening: That newfound flexibility isn’t from weeks of dedicated stretching. It’s from a pregnancy hormone called relaxin. And while it’s doing an important job preparing your body for birth, it can also put you at risk for joint injuries if you’re not careful.

Let me explain.

What Is Relaxin?

Relaxin is a hormone your body produces from the moment you get pregnant. Its job is simple: soften and loosen your ligaments and joints so your pelvis can open and expand during birth.

You need this. Your baby needs to pass through your pelvis, and relaxin makes that possible.

But here’s what catches most women off guard: Relaxin doesn’t just affect your pelvis. It affects your entire body.

Every ligament. Every joint. From your neck down to your ankles.

And it doesn’t just disappear after birth. Relaxin levels remain elevated for at least 5 to 12 months postpartum. If you’re breastfeeding, it can stay elevated even longer—some studies suggest up to two years.

So even when you’re months postpartum and feeling “back to normal,” your ligaments are still softer and looser than they were before pregnancy.

What Are Ligaments (And Why Does This Matter)?

Let’s talk about ligaments for a moment, because understanding this is key to understanding why relaxin matters.

Ligaments are the connective tissue that holds your bones together at your joints. Think of them as strong rubber bands that stabilize your skeleton.

They’re different from muscles:

• Muscles move your body and are elastic—they can stretch and bounce back
• Ligaments stabilize your body and have limited elasticity

Here’s the critical difference: If you overstretch a muscle, it can recover. If you overstretch a ligament, it can become permanently lax.

Think of an old hair tie. When it’s new, it snaps back. But stretch it too far, too many times, and it becomes loose and floppy. It doesn’t hold anymore.

That’s what can happen to your ligaments during pregnancy if you’re not careful. And because relaxin is making them softer and more pliable right now, they’re much easier to overstretch.

How You Might Notice Relaxin in Your Body

Most women first notice relaxin through sudden flexibility gains:

• Stretches that were always difficult suddenly feel easy
• You can fold forward deeper than before
• Hip stretches feel more open
• You can reach positions you’ve never been able to before

It feels amazing. Finally, your body is doing what you’ve always wanted it to do!

But that’s not flexibility you’ve earned through practice. That’s your ligaments being looser than they should be.

Less pleasant ways you might notice relaxin:

Hip instability: Your hips might feel “clicky” or unstable when you walk or roll over in bed

Pubic bone pain: Especially when opening your legs wide or climbing stairs

Lower back achiness: A general weakness or instability in your lower back

Wrist pain and carpal tunnel: Tingling or numbness in your hands, especially at night. This is incredibly common during pregnancy because relaxin makes the ligaments in your wrists lax and inflamed, putting pressure on the nerve running through your wrist.

After breastfeeding: Many women notice they suddenly feel less flexible again after they stop breastfeeding. That’s relaxin levels returning to normal and ligaments regaining their usual tension.

The Biggest Mistake: Going Deeper Because You Can

One of my students said something perfect last week: “I thought prenatal yoga was going to be stretching and breathing. But it’s not. It’s actually yoga with a belly in the way.”

She’s right. Prenatal yoga isn’t about getting more flexible or doing deeper stretches. It’s about adapting your practice to protect your body during these massive changes.

The biggest mistake I see? Students wanting to go deeper into stretches simply because they can.

They’ve never been able to touch the floor in a forward fold before. Now they can. So they think: “Great! Let me go even deeper!”

Or hip stretches that were always tight feel amazing. So they sink all the way down.

Or they can finally get into splits or really wide-legged positions.

Just because you CAN doesn’t mean you SHOULD.

You’re not getting more flexible in a beneficial way. Your ligaments are just looser. And if you push into that looseness, you’re overstretching the connective tissue that’s supposed to be holding your joints together.

Remember: Ligaments don’t bounce back like muscles do.

What This Means for Your Workouts

When you’re exercising during pregnancy—whether that’s yoga, Pilates, stretching, or any other activity—your goal is not to build more flexibility. Your goal is to build stability.

This is especially important to understand based on your natural body type:

If you’ve always been stiff: Suddenly being able to touch your toes is tempting. This newfound flexibility feels like a breakthrough. But you need to pull back. Go to about 80% of where you can go, not 100%.

If you’re already naturally flexible: You need to pull back even more. Your ligaments were already on the looser side. Now with relaxin, they’re even looser. You’re at higher risk for overstretching and causing joint instability.

I have naturally flexible students who want to show they can still do all the deep stretches during pregnancy. And I have to remind them: “I know you can, but you shouldn’t. Your job right now isn’t to prove your flexibility. It’s to protect your joints.”

What to Focus On Instead

Stability and strength.

In safe prenatal exercise, the focus shifts to:

• Standing poses that build leg strength
• Poses that engage muscles rather than passively stretching ligaments
• Active stretching where you use muscle engagement to control the movement, rather than sinking passively into gravity

Be especially careful with:

• Wide-legged stretches that put stress on pelvic ligaments
• Deep forward folds where you’re just hanging and letting ligaments stretch
• Deep hip openers that take your hip to its extreme range of motion
• Weight-bearing on wrists if you’re experiencing carpal tunnel symptoms

The 80% Rule

Here’s the rule I give all my students: Go to 80% of where you think you can go. Not 100%.

If you feel like you could fold all the way forward and touch the floor, stop at 80%. Leave some space.

If you feel like you could sink all the way down in a hip stretch, stop at 80%. Keep some muscle engagement.

I know it’s tempting. When you can finally do something you’ve never been able to do before, you want to push it. You want to see how far you can go.

But it’s not worth it. Pull back. Go to 80%. Your joints will thank you later.

This protects your ligaments, prevents overstretching, and keeps you safe for the long term. Because remember: pregnancy is temporary. But if you overstretch your ligaments now, you might deal with joint instability for years.

Postpartum: It Doesn’t End at Birth

This isn’t just pregnancy advice. It’s postpartum advice too.

For at least 5 to 12 months after birth, your relaxin levels remain elevated. If you’re breastfeeding, even longer.

So even when you’re cleared for exercise at 6 weeks postpartum, your ligaments are still softer than normal.

Don’t rush back into deep stretching. Focus on rebuilding strength and stability first. Your ligaments have been soft for over a year. Give them time to regain their normal tension before pushing into deep stretches.

Why Live Instruction Matters

Here’s the challenge: You can’t see yourself.

You can’t tell if you’re overstretching. You can’t assess your own joint alignment. You need someone watching who can say “pull back” or “engage more here.”

This is why at Krish Yoga Studio, all prenatal classes are live online, not recorded videos. I can see you through your camera and give you real-time feedback to keep you safe.

Having a trained teacher’s eyes on your practice isn’t a luxury during pregnancy—it’s essential.

The Bottom Line

Relaxin makes your ligaments soft and loose during pregnancy and postpartum. It affects your entire body, not just your pelvis.

This makes you feel more flexible, but it’s not real flexibility. It’s joint laxity. And if you push into it, you can cause permanent ligament damage.

Your goal during pregnancy: Build stability and strength, not flexibility.

Prenatal exercise isn’t about stretching and breathing. It’s about moving safely with a growing belly. It’s about protecting your body through incredible changes.

Go to 80% of your maximum stretch, not 100%. Especially if you’re naturally flexible.

Focus on strength work. Engage muscles during stretches. Don’t passively sink into extreme positions.

And remember: This applies postpartum too. Even after birth, relaxin levels stay elevated for months, especially during breastfeeding.

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