Is It Normal To Gain Weight When You Start Strength Training?

Let me answer this with a resounding yes. It is totally normal to see the number on the scale inch up when you begin a strength training routine—especially if you’re doing it consistently and challenging your muscles.

But don’t panic—this isn’t a bad thing. In fact, it might just be a sign that your body is making some really positive changes.

As someone who’s been strength training for decades (and has watched my body change through pregnancy, perimenopause, and post menopause), I can tell you firsthand: weight training is one of the best things you can do for your long-term health.

But yes, at first, the scale can be confusing. Let’s break it down.

Why You Might Gain Weight When Lifting Weights

There are a few key reasons your weight might increase when you start lifting, but it doesn’t mean you’re getting “fatter”—and it definitely doesn’t mean you’re doing anything wrong.

1. You’re Building Muscle (Yes, That’s a Good Thing!)

Muscle is your body’s metabolic engine. It burns more calories at rest than fat, takes up less space on your frame, and gives you that toned, sculpted look so many women are after. But—muscle weighs more than fat by volume. In other words, one pound of muscle takes up less space than one pound of fat on your body.

So as you lose fat and build muscle, the scale might go up even though your clothes fit better and your body looks tighter. That’s why it’s important to understand the difference between fat loss and weight loss!

Think about it this way: would you rather weigh a bit more and feel strong, capable, and energetic? Or weigh less but be soft, sluggish, and weak? That’s a mindset shift I wish more women embraced. And believe me, I had to work on that myself.

Now, I don’t care what I weigh on the scale, I care how my clothes fit. 

2. Inflammation & Water Retention from New Workouts

Starting a new strength routine creates tiny tears in your muscle fibers—this is how you build strength. But that process can also lead to short-term inflammation and water retention as your body works to heal and adapt.

This is temporary and a totally normal part of getting stronger.

3. Hydration & Hormonal Shifts

Your hydration levels, sodium intake, and hormones all affect water retention and weight fluctuation. Lifting weights can indirectly impact all three.

Especially during perimenopause and post menopause, hormones can make our weight bounce around more than usual. Use these tips to help balance hormones for weight loss in middle age!

Be kind to your body, and don’t let the scale boss you around.

4. Stress, Sleep & Cortisol

If you’re under stress or skimping on sleep, your cortisol levels may be higher—and that hormone can lead to water retention and cravings. Don’t forget: rest and recovery are part of your fitness plan.

A good night’s sleep and a rest day can do wonders for both your mood and your metabolism.

These are the tips I used to lower my cortisol levels during menopause!

Focus on Body Composition, Not Just the Scale

If you’re strength training regularly and eating a healthy, balanced diet, you’re likely losing fat and gaining lean muscle—even if the scale isn’t budging or is going up slightly. That’s where body measurements, progress photos, how your clothes fit, and how you feel in your body come into play.

Your body is changing from the inside out. Muscle helps rev your metabolism, improves bone density, and keeps you strong for the long haul. And trust me—there’s no better feeling than seeing yourself get stronger over time.

The Long-Term Payoff of Lifting Weights

As we get older—especially into our 40s and beyond—we naturally lose muscle mass if we don’t actively work to preserve it. This loss of muscle is one of the main reasons why our metabolism slows down and why daily tasks (like carrying groceries or picking up grandkids) can start to feel harder.

Lifting weights isn’t just about aesthetics—it’s about longevity. Muscle is the key to aging well. It helps you:

• Stay mobile and independent
• Prevent injuries and falls
• Maintain bone density
• Boost your resting metabolism
• Improve your mental health and confidence

And here’s the kicker: strength training is actually a long-term weight loss tool. You might gain a little at first, but over time, you’ll burn more calories at rest and build the kind of body that’s resilient and energetic.

These are my favorite strength training moves for women over 50.

What To Do If the Scale Is Stressing You Out

If stepping on the scale is causing anxiety, give yourself permission to take a break from it. Seriously. You’re not obligated to weigh yourself daily (or even weekly). Here’s what you can do instead:

• Track non-scale victories (NSVs) in a journal: strength gains, mood boosts, better posture
• Focus on how workouts make you feel, not just how they make you look
• Celebrate your consistency—it’s the most powerful tool in your wellness toolbox

Remember: the scale is just one tiny data point in a much bigger picture. 

One Caveat: Lifting Weights Doesn’t Mean You Can Eat Whatever You Want

I mentioned earlier a healthy balanced diet. Here is a gentle but important reminder: just because you’re lifting weights doesn’t mean you get a free pass to eat anything and everything.

I’ve worked with many women who assume that strength training means they need to eat significantly more—or that they’ve “earned” extra indulgences. But the truth is, your nutrition still matters a lot.

Yes, strength training does increase your calorie burn and your metabolism over time—but not so much that it cancels out poor eating habits.

What your body really needs when you’re lifting is:

• Clean, nutrient-dense food
• Plenty of high-quality protein to support muscle repair
• Smart portions (especially as we get older and our metabolism naturally shifts)

You don’t need to overeat, but you do need to eat with intention—especially if fat loss or body composition changes are your goals.

Think of food as fuel. Eating more protein, colorful anti-inflammatory veggies, healthy fats, and whole grains can help you feel stronger and more energized. Avoid the processed snacks, sugary treats, or mindless late-night eating. 

Lifting weights is powerful—but it works best when it’s paired with balanced, intentional eating.

Your Strength is More Than a Number

So yes, it’s normal to gain a little weight when you start lifting weights. But no, that doesn’t mean you’re failing. Quite the opposite—you’re investing in your long-term health, strength, and independence.

As I always say: aging is inevitable, but how you age is up to you. Lifting weights is one of the best gifts you can give your future self.

Keep going, trust the process, and celebrate your strength every step of the way!