From 2 videos
How much muscle mass do women lose after 40?
Answered by WarriorBabe's coaches · Updated
The short answer
Women naturally lose 3-8% of their muscle every decade after 40, according to one WarriorBabe coach. Because muscle keeps your metabolism running, losing it means burning fewer calories at rest and storing fat more easily, especially around the midsection. Strength training and eating to support your body help you build and protect that muscle.
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A WarriorBabe coach on the 3-8% muscle loss per decade and what it does to metabolism
Plays from 2:32 · Video: Always Exhausted After 40? Why Strength Training Helps
Why it's never too late to build muscle, and why 90 minutes a week is enough
Plays from 6:22 · Video: Always Exhausted After 40? Why Strength Training Helps
Why strength training matters in menopause for your health 20 years from now
Plays from 3:07 · Video: Why Getting Fit After 40 Is About More Than Looks
The full answer
On The WarriorBabe Show, one coach explains that the 3-8% loss per decade compounds if nothing changes. If you don't adjust your diet to support your body, you lose even more muscle over time, which slows your metabolism further. Your body burns fewer calories at rest even when your activity level stays the same. That's why you can eat the same foods you always have and still gain weight, and why it often shows up as stubborn belly fat. It isn't your imagination, and it isn't a lack of willpower. Your body is handling food differently, so the plan has to change.
The fix she points to is strength training, paired with the right amount of protein, carbs and fats. Lifting builds and protects lean muscle, which she calls your metabolism's best friend and your body's energy reserve. She also says it helps with blood sugar regulation, sleep, mood and mental clarity. A few myths she clears up:
- Muscle tones you rather than bulking you up. Looking bulky takes extremely heavy lifting, a large calorie surplus and often specific supplements.
- You're not too old. She notes that studies show women can build strength and muscle well into their 70s and beyond.
- You don't have to live in the gym. About 90 minutes a week is enough, and she says it's more effective than daily cardio.
Another WarriorBabe coach adds a longer view. If you're not eating enough or don't have much muscle when you reach a phase like menopause, strength training becomes especially important, because what you do now paves the path for where your health will be 20 years from now. If you're navigating menopause, it's worth bringing your doctor into the conversation as you build your plan.
From WarriorBabe's coaches (how we write our answers). For education, not medical advice: talk to your doctor about your own health.
Part of
Building Muscle After 40 →- How long does it take to build muscle after 40?
- Can too much cardio make you lose muscle?
- How do I go from a building phase into a fat loss phase?
- How many calories should I eat to build muscle after 40?
- Is it normal to gain some fat when building muscle?
- Why am I not building muscle even though I work out?
Women also ask
More questions →
Building Muscle After 40
Why does the scale go up during a muscle-building phase?
The scale goes up during a muscle-building phase because you're eating more food, and food has weight. The extra carbs are stored as glycogen, which holds about three to four grams of water per gram. You're also adding muscle, and Nikkiey says a small amount of fat comes with it. That is normal and expected.
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Building Muscle After 40
Why is muscle so important for women over 40?
Muscle matters after 40 because it drives your metabolism and protects your long-term health. Nikkiey explains that women lose about 3 to 8 percent of muscle per decade after 30, and less muscle means a slower metabolism. She calls muscle the engine of your metabolism and, borrowing Dr. Gabrielle Lyon's phrase, the organ of longevity.
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Building Muscle After 40
Can I build muscle in a calorie deficit?
Yes, you can build some muscle in a calorie deficit, especially if you're newer to strength training or have more fat to lose, but not as much as at maintenance or in a surplus. Nikkiey explains that a modest deficit, enough protein and a real lifting program work. Crash-level calories like 1,200 don't.
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Watch or listen in full
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