The Ideal Percentage of Muscle by Gender & Age — Why It Matters for Longevity, Metabolic Health, and Physical Function, and How to Find Out What Yours Is With a DEXA Scan at Styles Studios Fitness
- Styles Studios Fitness
- 3 minutes ago
- 4 min read
When most people think about body composition, they think about body fat. But the most important number for your long-term health — the number that predicts how you move, age, burn calories, and stay independent — is actually your lean muscle mass.
Muscle is not just a “fitness” metric. It’s a vital organ of longevity.
Hormone health, metabolic health, functional strength, balance, mobility, injury prevention, aging rate — all of it ties back to how much muscle you carry.
And yes… the ideal percentage of muscle changes by age and gender.
Let’s break it down in a simple, science-backed way.
First: What Counts as “Muscle Percentage”?
When we talk about your “muscle percentage,” we’re referring to the portion of your total body weight that is made up of skeletal muscle mass — the muscles responsible for movement, strength, stability, and metabolic activity.
This can be measured accurately using a DEXA scan (Styles Studios Fitness specialty!), which gives the most precise picture of lean mass, fat mass, bone density, and regional distribution.
Ideal Muscle Percentage Ranges
These ranges vary because men and women naturally have different hormone profiles, and aging naturally reduces muscle over time — unless we intervene.
Below are healthy, functional, longevity-promoting ranges based on category, not bodybuilding standards.
Women (Age-Based Muscle Percentage Ranges)
Ages 20–39:➡ 30–35% muscle is ideal(Highly fit individuals may be 36–40%)
Ages 40–59:➡ 28–33% muscle is ideal(36%+ for very active women)
Ages 60+:➡ 26–31% muscle is ideal(Anything above this is protective and strongly longevity-positive)
Why women must prioritize muscle:
Women lose muscle 2× faster after menopause
Muscle preserves bone density and reduces fracture risk
Muscle improves insulin sensitivity, lowering diabetes risk
Muscle protects hormonal balance and metabolic rate
Men (Age-Based Muscle Percentage Ranges)
Ages 20–39:➡ 38–45% muscle is ideal(46–50% for athletic men)
Ages 40–59:➡ 36–43% muscle is ideal
Ages 60+:➡ 33–40% muscle is ideal(Higher = dramatically reduced mortality risk)
Why men must prioritize muscle:
Testosterone decreases gradually after age 30
Muscle preserves metabolic rate and prevents “middle-age spread”
Muscle protects heart health
Muscle reduces inflammation and improves physical power and mobility
Why Muscle Percentage Matters So Much
1. Muscle Is Your Metabolic Engine
More muscle = higher resting metabolic rate.
This means:✔ Easier fat loss✔ Easier maintenance✔ Better glucose control✔ Better insulin sensitivity✔ Lower inflammation
This is why people with higher muscle mass have significantly lower risk of diabetes, heart disease, and obesity.
2. Muscle Is Your Body’s Anti-Aging System
Muscle communicates with the brain, immune system, and hormones through powerful compounds called myokines.
These trigger:
Anti-inflammatory effects
Improved cognitive function
Better immune response
Better mood
Improved longevity pathways
People with higher lean mass age slower on a cellular level.
3. Muscle Protects Your Physical Independence
As we age, our biggest risks are:
Falls
Fractures
Loss of mobility
Sarcopenia (muscle wasting)
Adequate muscle percentage drastically reduces all of these.
Muscle = stability Muscle = balance Muscle = the ability to live your life without limitation
4. Muscle Is the Gateway to a Healthy Hormone Profile
Muscle helps regulate:
Testosterone
Estrogen
Insulin
Thyroid hormones
Cortisol
When muscle drops, hormone dysfunction rises.When muscle increases, hormones balance more easily — even during aging.
5. Muscle Improves Every Outcome of Longevity
Research consistently shows:
People with higher lean muscle mass:
✔ Live longer✔ Have lower disease risk✔ Recover faster✔ Maintain better brain health✔ Experience fewer metabolic issues✔ Enjoy higher quality of life
Muscle isn’t optional. It’s essential.
How to Increase Your Muscle Percentage Effectively
1. Strength Train 2–4 Days/Week
Focus on compound lifts and progressive overload.(HUSTLE by Styles workouts are one of the best formats for this.)
2. Eat Enough Protein
0.8–1g per pound of goal body weight. Most people drastically under-eat protein.
3. Prioritize Recovery
Muscle grows during rest, not during workouts.
4. Support Hormones if Needed
For those in their 40s, 50s, and 60s: HRT, peptides, testosterone therapy, and metabolic testing can accelerate muscle gain safely. Check out our B3 Med Spa inside Styles and let our incredible Doc do blood labs and show you where your body is at right now and what it might need to optimize it.
5. Track Your Muscle %
DEXA scans are your gold standard — especially when paired with lifestyle changes or Med Spa support.
Final Takeaway: Muscle Is Medicine
Whether you’re in your 20s, 40s, or 70s, your muscle percentage is one of the strongest predictors of how long — and how well — you will live.
The goal isn’t to be as lean as possible. The goal is to be as strong and functional as possible.
More muscle =More energy More vitality More mobility More metabolic health More hormonal balance More longevity More life in your years.
If you want help understanding your current muscle percentage and how to improve it, we can build you a personalized plan using DEXA scans, strength training, nutrition, and Med Spa support.
Just say the word — we’re here to help you build your strongest, longest-lived self.
Book your scan today! https://www.stylesstudiosfitness.com/dexa-recovery
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