I experienced a bit of a reality check lately. In my earlier years, building muscle used to be so much easier. My quads used to grow just by looking at a weight rack! But…as I’m navigating my 40s, building muscle—even in my quads—is getting more and more difficult, and it can be so frustrating.
In our 40s and beyond, our estrogen levels drop, our metabolism changes, and what used to work, especially when it comes to building muscle, just isn’t working anymore.
Ladies, your body is not broken. Your strategy just needs to shift. You are the CEO of your own health—you and only you, and that is especially true when it comes to building muscle after 40.
The TL;DR
The Reality: Muscle loss (sarcopenia) accelerates after 40 due to shifting estrogen and cortisol levels. It’s not you—it’s biology.
The Protein Rule: Aim for 80-100% of your body weight in grams of protein to protect your metabolism and repair tissue.
The Training Shift: Move away from “light weights” and focus on lifting to 1-2 reps before failure to trigger growth.
The Mindset: Think like a Bamboo Tree. Progress is happening “underground” long before you see the definition in the mirror.
Read the full post below to master your “Muscle Building Trifecta.”
Why Does Muscle Loss Happen? (The Science)
Muscle loss, otherwise known as sarcopenia, naturally happens during our 40s and beyond, even when we’re doing our best to maintain and build that muscle. Experts found that our muscle mass and strength peak around age 35, small declines happen in our 40s, and we lose 5-10% of our muscle mass every decade after age 50.
The Hormonal “Triple Threat”
In perimenopause, shifting hormone levels create a challenging environment for our muscles. Here is how the “Big Three” affect your strength:
Estrogen
Levels drop, negatively impacting your body’s ability to repair and grow new muscle tissue.
Cortisol
Levels often rise, which can act as a “muscle destroyer,” breaking down the tissue you work so hard for.
Insulin
Shifts can lead to resistance, making it significantly harder to maintain a healthy weight and build lean mass.
This hormonal combination makes sarcopenia (muscle loss) a reality, but with the right strategy, you can override these changes.
Learn more about how these three hormones—estrogen, cortisol, and insulin—can affect perimenopausel weight gain + weight loss in my full perimenopause guide.
Besides improving our quality of life AND helping us look healthier and fitter, our muscle mass is the #1 predictor of longevity and metabolic health as we age. Our muscles literally make up our body’s protective armor, and when that armor is strong, we can enjoy the following benefits now and way into the future:
- Boost metabolism
- Decreased risk of heart disease, certain types of cancer, and type 2 diabetes
- Decreased risk of falls
- Improved mental health
- Lower risk of injury
- Increased bone strength
- Improved brain health
- Decreased blood pressure
To help you build that precious muscle after 40 or during whatever stage of life you’re in, I’m sharing four pillars to help you get there.
The Muscle Building “Trifecta:” Your Foundation for Building Muscle After 40
We’ve been told for generations that staying fit as we age is all about “eating less and moving more.” This just isn’t true, and it can actually work against your goals. Building a strong, resilient body—especially through perimenopause and beyond—is about three specific pillars. I’m sharing these because they are absolute game-changers for your metabolism, bone health, and overall confidence!
The Muscle Building Trifecta
Forget the “light weight” myths. To see real results and protect your metabolism, you need to master these three pillars.
1. Nutrition & The 120g Rule
Stop “cannibalizing” your muscle. Protein is the building block for literally everything in your body.
- The Goal: Aim for 80-100% of your body weight in grams of protein (e.g., 140lbs = 112-140g).
- Metabolic Boost: Your body burns 20-30% of protein calories just during digestion.
- Simple Swaps: Use Greek yogurt, cottage cheese, and shakes to hit your daily number easily.
2. Consistency Over Perfection
One missed workout won’t ruin progress, but giving up will. Think like a Bamboo Tree.
- Deep Roots: Progress is often invisible underground before you see the “shoot” above the surface.
- Mindset Shift: Consistency beats perfection any day of the week.
- Long Game: Real muscle definition comes from showing up, even when you don’t “see” it yet.
3. Lift Heavy (Drop the Myth)
Resistance training is the “Body Armor” that saves your bones and keeps your metabolism firing.
- Heavy Lifting: Aim to be 1-2 reps away from muscle failure to override hormonal changes.
- Form is Everything: Slow down movements to ensure laser-like focus on safety.
- Bone Strength: Heavy loads signal your body to build density and strength as you age.
Click here for an Instagram video where I break a lot of this down too!
Pillar 1: Nutrition & the 120g Protein Rule
I’ve seen it again and again and again. We think we need to eat less to maintain a healthy weight or to even lose a few pounds, and yes, eating fewer calories than we burn is one of the keys to weight loss. But…and this is a huge BUT…we often cut calories so much that we actually lose muscle in the process. I know, I know. This goes against all the “info” we’ve been fed for years and years.
Here’s the deal: As I shared above, our muscle-building hormones naturally take a hit as we age. If we’re not eating enough fuel for our bodies, especially protein, our cortisol levels can go even higher, meaning we’re literally cannibalizing our own muscle. And that is SO not good.
When it comes to building muscle outside of our workouts, protein is king. Why? This incredible macronutrient can help control appetite, build muscle (of course!), improve bone health, improve exercise and injury recovery, boost metabolism + increase fat burn, and lower blood pressure. And…if weight loss or maintenance is your goal, your body will use up 20-30% of every protein calorie you eat simply digesting that calorie.
I hear you…”That is a LOT of protein, Heidi!” Yes, it is. But nailing your protein goal every day isn’t as hard as you might think. Protein powders + shakes, lean meats, cottage cheese, and Greek yogurt are super simple ways to hit your number, and all offer the bonus micronutrients we need too.
Pillar 2: Consistency Over Perfection
I’m a recovering perfectionist. And over the years, I’ve learned one valuable truth: No one can be perfect. It’s impossible. But I still find myself thinking those dang perfectionistic thoughts when it comes to my goals.
Here’s what I’ve learned: Consistency beats perfection any day of the week. When we think we’ve failed because we’ve missed a workout, or overindulged food-wise, or any of the other thousands of things that can go wrong when we’ve got a goal, it’s so tempting to just give up because we’re not perfect. Again, no one is perfect.
I’ve got a powerful mindset shift that can make all the difference when we’re battling that dang, never-achievable perfectionism:
- One missed workout won’t ruin your progress, but a missed month will.
- One missed “anything” won’t ruin your progress, but giving up will.
When it comes to building muscle, you will not see progress on day one. Or even on day 14. Or maybe even for weeks. But, as long as you’re showing up consistently for your workouts, you will see and feel progress. It’s like the Bamboo Analogy:
The bamboo tree spends years growing deep roots underground before anything appears above the surface. Then, almost suddenly, it shoots up rapidly in a short amount of time, forming a large, powerful, towering, beautiful bamboo tree.
Like bamboo, our muscle growth is often invisible at first because it’s being built through small, consistent efforts—that “rooting” underground stage. What looks and feels like snail-like progress is actually building a strong foundation, making all that muscle growth we want possible. And like the bamboo tree appearing to rise suddenly, we will all of a sudden see that muscle definition we’ve been working so hard for.
Pillar 3: Lift Heavy—Drop the “Light Weight” Myth
Cardio is important for heart health. That’s a proven fact. However, resistance training is THE thing that saves our bones and metabolism. And while any resistance training can be effective, to power-up that body armor and get the most benefits from that precious time we spend lifting weight, HOW we lift weights can make all the difference.
Remember: To get the gains we want, both physically and perimenopause-wise, lifting heavy is the key.
From “Rooting” to “Rising”
Building muscle after 40 can feel like just one more thing you need to do to navigate this often strange-feeling season of perimenopause. Some days, it might even feel impossible. But please remember this: It’s not impossible. It just takes intention. It doesn’t take hours in the gym. It takes making space 2-3 days a week to challenge your body with some resistance training. And if I have one key takeaway for you today, it’s this: The work you do today—even if that work is just a few minutes—is setting the foundation for the next 20+ years of your life. You’re creating those roots that will result in the future you want—your own powerful, beautiful bamboo tree.
Ready to stop guessing and start growing? Join my Show Up App where we’ll put these 4 pillars into practice together.
Have a question about my 120g protein goal? Drop a comment below!
Xo,
Related reading: Check out these posts for more muscle-building tips!
Top 10 At-Home Exercises for Total Body Toning
My (Almost) Famous Pumpkin Pie Overnight Oats
Total Body Burner: At-Home Kettlebell Workout
One-Minute Chocolate Brownie
8 Resistance Band Moves You Can Do Anywhere
What’s for Dinner? Garlic Parmesan Chicken
At-Home 20 Minute Total Body Burner