Understanding muscle mass can be confusing because it is closely related to overall body composition. While there is no single perfect number that applies to everyone, knowing the basics can help you better track your health and fitness progress.
What is muscle mass?
Your total body weight is made up of two main parts:
- Body fat
- Lean body mass
Lean body mass includes everything in your body that is not fat, such as:
- Muscles
- Bones
- Organs
- Water
- Skin
Muscle mass specifically refers to the weight of your body’s muscle tissue, mainly skeletal muscle. This is the type of muscle responsible for movement, posture, strength, and physical performance.
Maintaining healthy muscle levels becomes especially important with age, as it supports balance, mobility, and overall independence.
Average muscle mass ranges
Measuring exact muscle mass is difficult, and there are currently no universal “ideal” standards. However, research provides estimated averages for skeletal muscle percentage based on age and gender.
Average muscle mass percentage in men
- 18–35 years: 40% – 44%
- 36–55 years: 36% – 40%
- 56–75 years: 32% – 35%
- 76–85 years: below 31%
Average muscle mass percentage in women
- 18–35 years: 31% – 33%
- 36–55 years: 29% – 31%
- 56–75 years: 27% – 30%
- 76–85 years: below 26%
These values are only general references, as muscle mass varies widely depending on genetics, activity level, diet, and lifestyle.
How is muscle mass measured?
Accurately measuring muscle mass is not simple and usually requires medical-grade equipment. Some advanced methods include:
- MRI (Magnetic Resonance Imaging)
- CT (Computed Tomography) scans
- DEXA body scans
- Ultrasound imaging
- Bioelectrical impedance analysis
- Specialized dilution techniques
Among these, imaging techniques like MRI and DEXA are considered the most accurate.
However, even these tools can produce slightly different results depending on the method used.
Can you measure muscle mass at home?
While home methods are not perfectly accurate, they can still give you a general idea of body composition. Common options include:
- Smart body fat scales
- Skinfold calipers
- Waist and hip measurements
- Online body composition calculators
- Gym-based body analysis machines
These tools are useful for tracking trends over time, even if the exact numbers are not 100% precise.
Is more muscle mass better?
In most cases, having a healthy level of muscle mass is beneficial for overall health.
As people age, they naturally lose muscle, a condition known as age-related muscle loss. This process usually begins around the age of 40 and can continue gradually over time.
Lower muscle mass is linked with:
- Reduced strength and mobility
- Higher risk of falls and injuries
- Slower metabolism
- Increased risk of chronic conditions such as diabetes and heart disease
- Reduced independence in older age
Maintaining muscle supports better physical performance, metabolic health, and quality of life.
Some research also suggests possible benefits for brain health and emotional wellbeing, although more studies are needed.
Can you have too much muscle?
Very high levels of muscle mass can sometimes come with practical challenges, such as:
- Difficulty finding properly fitting clothing
- Higher calorie needs to maintain weight
- Possible stiffness if flexibility training is ignored
However, many of these issues can be managed with balanced training and proper nutrition.
How to increase muscle mass
Building muscle requires a combination of exercise and nutrition.
1. Strength training
Resistance training is the most effective way to build muscle. It forces muscles to adapt by working against resistance.
Examples include:
- Bodyweight exercises (push-ups, squats)
- Free weights (dumbbells, barbells)
- Resistance bands
- Weight machines
- Functional training or HIIT workouts
Experts generally recommend at least two strength training sessions per week targeting all major muscle groups.
2. Nutrition for muscle growth
Food plays a major role in muscle development and recovery.
Key nutrients include:
Protein: Essential for muscle repair and growth
Sources include:
- Meat and poultry
- Fish and eggs
- Dairy products
- Beans, lentils, and nuts
Carbohydrates: Provide energy for workouts
Choose whole grains, fruits, and vegetables for better results.
Healthy fats: Support hormone balance and overall health
Found in nuts, seeds, oils, and fatty fish.
A balanced diet helps your body recover faster and build stronger muscle tissue.
Final thoughts
Muscle mass is an important part of your overall body composition and plays a key role in strength, mobility, and long-term health.
Although exact measurement is difficult, maintaining and building muscle through regular exercise and good nutrition is one of the best ways to improve fitness and protect your health as you age.
Instead of focusing only on numbers, it is more useful to track strength, energy levels, and overall physical performance over time.
