Muscle mass plays a central role in strength, mobility, and overall health.
But how much should you actually have, and how do you find out? Here is an overview of what the research shows.
What does body mass consist of?
Your body weight generally consists of body fat and fat-free mass. Fat-free mass includes more than just muscles, encompassing bones, skin, organs, and fluids as well.
The difference between fat-free mass and muscle mass
The terms are often used interchangeably, but they are not identical. Muscle mass is only a part of fat-free mass and refers specifically to the body’s muscle tissue.
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What does muscle mass include?
Muscle mass includes skeletal muscles, smooth muscle, and the heart muscle. In everyday language, however, muscle mass typically refers to skeletal muscle.
The importance of skeletal muscles
Skeletal muscles control the body’s movements and posture. They are essential for balance, mobility, and strength, and their importance increases with age.
No official recommendations
There are no fixed guidelines for how much muscle mass a person should have.
The amount of muscle depends on factors such as height, diet, ethnicity, and physical condition.
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How muscle mass is measured most accurately
Advanced scans such as MRI, DEXA, and CT are used to measure muscle mass.
According to a 2020 review published in Obesity Surgery, imaging methods are considered the most accurate standard.
Study from 2000
In 2000, researchers conducted a study published in the Journal of Applied Physiology, measuring the percentage of muscle mass in 468 adults across several age groups.
Although the figures provide an indication of muscle mass across age groups, the researchers emphasize the need for updated studies to present a more current picture.
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18 to 35 years
In this age group, muscle mass is at its highest. Men have an average muscle mass of between 40 and 44 percent, while women range between 31 and 33 percent.
It is typically during these years that the body has the greatest proportion of skeletal muscle.
36 to 55 years
As age increases, muscle mass begins to decline.
Men between 36 and 55 years have an average muscle mass of 36 to 40 percent, while women in the same age group range between 29 and 31 percent.
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56 to 75 years
The decline in muscle mass continues during this period. Men’s average muscle mass ranges between 32 and 35 percent, while women range between 27 and 30 percent.
76 to 85 years
In the oldest group in the study, the lowest levels were observed. Men have under 31 percent muscle mass, and women have under 26 percent.
This reflects the age-related loss of muscle mass that occurs gradually throughout life.
The role of exercise
Strength training is an effective way to build muscle. This can include bodyweight exercises, free weights, machines, resistance bands, HIIT, or Pilates.
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Adults are advised to engage in at least two weekly strength-training sessions that activate all major muscle groups.
The importance of diet
A balanced and nutrient-rich diet is essential for both building and maintaining muscle.
Protein plays a central role, and between 10 and 35 percent of daily calories should come from protein.
Carbohydrates, fats, vitamins, and minerals are also necessary, and it is recommended to limit ultra-processed foods.
Sources: Healthline, Obesity Surgery, and Journal of Applied Physiology.