Why Muscle Mass Matters—Especially for Women
Why Muscle Mass Matters—Especially for Women
By Dr. Simone Sturm
If you’ve ever stepped on a smart scale, hoisted yourself into a DEXA scan—or simply felt concerned after noticing your muscle mass percentage—you’re not alone. Understanding what constitutes a healthy muscle mass for women by age can be transformative, not just for fitness goals, but for lifelong vitality.
Benchmarks by Age: What is “Healthy”?
Recent data from a study with over 18,000 adult women shows that healthy muscle mass percentages—the proportion of skeletal muscle relative to total body weight—typically range between 27% and 33%, depending on your age.
Here’s how that breaks down:
18-35 years - 31 to 33%
36-55 years - 29-31%
56-75 yers - 27-30%
76-85 years - <26%
Aging, Muscle, and Why It Matters
Two important patterns emerge:
Peak, Then Decline
Absolute muscle mass (in pounds or kilograms) often peaks around age 40–49.
But when looked at as a percentage of body weight, muscle mass gradually declines starting around age 30 and accelerates—especially after age 50—by approximately 5.7% per decade .
2. Gender perspective
Women’s peak muscle mass generally hovers around 30–31%, while men average closer to 38%.
But “lower” doesn’t mean less effective—women often achieve impressive strength and functional benefits relative to body size.
Why Muscle Percentage Helps, More Than Total Weight
Skeletal muscle does much more than help you lift heavy objects—it underpins your metabolism, movement, and metabolic resilience:
Metabolic engine: Muscle consumes approximately 4.5–7 calories per pound per day at rest, boosting your basal metabolism.
Strength & function: Enough muscle protects against falls, supports independence, and makes daily activities—like standing up or climbing stairs—easier.
Bone & hormonal health: Resistance training that builds muscle also strengthens bones. Muscle also plays a role in blood sugar regulation and hormone balance.
What Should You Do About IT?
1. Get an accurate baseline
The most precise way to measure muscle mass is a DEXA scan, which also tracks fat and bone density—all in a short 10–15 minute session. Smart scales, like the InBody, use bioelectrical impedance; they’re great for tracking trends, although hydration and other factors can skew results. The gold standard is truly the DEXA, but bioelectrical impedance is great for more regular checks and to follow trends over time. I generally recommend a DEXA once a year and bioelectrical impedance every couple months (especially if you are currently on a weight loss journey or working on body recomposition).
2. Build a strong, sustainable plan
Research consistently supports these pillars:
Resistance training (2–4 times/week): Prioritize compound movements and progressive overload to build and maintain muscle.
Protein intake (1.4–2.0 g/kg/day): Spread high-quality sources—lean meats, fish, legumes, dairy — about 30 g per meal to support muscle synthesis.
Recovery matters: Aim for 7–9 hours of restorative sleep, stress management, proper hydration, and scheduled rest days. Remember—muscle growth happens during recovery, not during the workout!
Why This Matters for Your Healthspan
Maintaining healthy muscle mass isn’t about chasing athletic numbers—it’s about preserving mobility, metabolic function, hormone balance, and independence as you age. From your 40s through your 60s and beyond, an intentional focus on muscle becomes a cornerstone of longevity.
Ready to Get Started?
If you’d like to quantify your muscle mass, track progress, and develop a personalized plan that fits your life and goals, consider scheduling a body composition analysis at Denver Holistic Medicine. Let’s build the foundation for a vibrant and resilient future—together.