Introduction
Lean body mass (LBM) is an important measure of health and fitness. It comprises all the components of your body except fat mass, including muscles, bones, organs, tissue, and water content. Having the right amount of lean mass allows for optimal body function and strength. This article discusses how to determine ideal lean body mass and tips to build yours.
Gender VS Lean Body Mass
On average, men have a greater absolute amount of lean body mass compared to women. Women generally have more body fat than men, even when they weigh the same. This is because women need more body fat to support pregnancy and childbirth. As a result, women typically have less muscle mass than men.
For example, a woman with 25–31% body fat is considered average, while a man with 18–24% body fat is considered average. This means that a typical woman's body is about 69–75% muscle, while a typical man's body is about 76–82% muscle.
Total Lean Body Mass On Average
Adult men have:
More total lean body mass than women
LBM of around 120–150 lbs or 54–68 kg
Adult women have:
Less total lean mass than men
LBM of typically 90–110 lbs or 41–50 kg
So men have around 30–40 more lbs (14–18 kg) of total lean mass on average. However, stronger men at elite levels can reach over 200 lbs (90 kg) of lean body mass.
Age VS Lean Body Mass
As we age, our bodies undergo several changes, including a decline in lean body mass. This loss of muscle mass is known as sarcopenia and can have a significant impact on our overall health and well-being.
The decline in LBM begins around age 30 and accelerates after age 60. This is due to a number of factors, including:
Decreased hormone production: Hormones such as testosterone and growth hormone play a role in maintaining muscle mass. As we age, the production of these hormones declines.
Reduced physical activity: As we get older, we tend to be less physically active. This lack of activity can lead to a loss of muscle mass.
Changes in protein synthesis: The body's ability to synthesize protein, the building block of muscle, decreases with age.
Lean Mass Development Stages
Lean mass corresponds to everything in your body minus fat:
- It rapidly increases from birth through end of puberty
- Reaches maximal levels in early 20s
- Slowly declines through 30s and 40s
- Drops more quickly over 50 years old
So the pattern forms an inverted U shape over the lifespan.
Quantifying Age-Related Lean Mass Losses
Typical losses by decade:
- 20–30 years old: gain 1-2% per decade
- 30–50 years old: Lose 1–2% per decade
- Over 50 years old: Lose 3–5% per decade
An 80-year-old may have 20% less total lean mass than their 30-year-old peak.
How Much Lean Body Mass Should I Have?
The amount of lean body mass (LBM) you should have depends on several factors, including your age, sex, and activity level. However, as a general rule of thumb, women should aim for a LBM of at least 30% of their total body weight, while men should aim for a LBM of at least 40%.
Understanding your total daily energy expenditure can help you determine the optimal calorie and macronutrient intake to support your desired lean body mass goals. Naturally, getting enough protein is crucial for building and maintaining muscle.
How to Measure LBM
There are a few different ways to measure lean body mass (LBM), each with its own advantages and disadvantages. Here are a few of the most common methods:
Skinfold calipers: This method involves using calipers to measure the thickness of skinfolds at various points on the body. Skinfold calipers are relatively inexpensive and easy to use, but they can be inaccurate if not used correctly.
Bioelectrical impedance analysis (BIA): This method uses electrical currents to measure the resistance of body tissue. BIA is a more accurate method than skinfold calipers, but it is also more expensive and time-consuming.
Hydrostatic weighing: This method involves weighing yourself underwater and then subtracting the weight of the water displaced to determine your LBM. Hydrostatic weighing is the most accurate method of measuring LBM, but it is also the most expensive and time-consuming.
Dual-energy X-ray absorptiometry (DEXA): This method uses low-dose X-rays to measure the amount of bone, muscle, and fat in your body. DEXA is the most accurate and comprehensive method of measuring LBM, but it is also the most expensive and requires specialized equipment.
Formulas to Estimate Lean Body Mass
Here are two common equations for estimating body mass:
For Men
LBM (kg) = 0.407 × (weight in kg) + 0.267 × (height in cm) − 19.2
For Women
LBM (kg) = 0.252 × (weight in kg) + 0.473 × (height in cm) − 48.3
Plugging in your weight and height gives reasonable approximations.
The Average Lean Body Mass for Women
The average amount of muscle women have varies depending on how old they are and how active they are.
- Age 20-29: 32%
- Age 30-39: 31%
- Age 40-49: 30%
- Age 50-59: 29%
- Age 60+: 28%
The Average Lean Body Mass For Men
The average LBM for men also varies depending on age and activity level. However, as a general rule of thumb, the average LBM for men is as follows:
- Age 20-29: 42%
- Age 30-39: 41%
- Age 40-49: 40%
- Age 50-59: 39%
- Age 60+: 38%
Please note that these are just averages, and your individual LBM may vary. If you are concerned about your LBM, you should talk to your doctor.
Tips to improve or maintain your LBM
Here are some tips to improve or maintain your LBM:
Eat enough protein. To build muscle, you need to eat enough protein. Aim to eat at least 0.8 grams of protein per kilogram of body weight every day. Eating enough protein will help your muscles grow and repair themselves.
Strength training is done regularly. Strength training is an important part of building and keeping muscle mass. It helps you get stronger and build bigger muscles. Aim to strength train for at least two hours each week. This means working out all of the major muscle groups in your body.
Get enough sleep. When you sleep, your body repairs and rebuilds muscle tissue. Aim for 7-8 hours of sleep per night.
Manage stress. When you're stressed, your body releases a hormone called cortisol. This hormone can break down muscle tissue, making it harder to build and maintain muscle mass. Find healthy ways to manage stress, like yoga, meditation, or spending time outdoors.
Stay hydrated. Water is important for all bodily functions, including muscle growth and repair. Aim to drink eight glasses of water per day.
Consider creatine supplements. Creatine is a natural substance that helps your muscles produce energy. Creatine supplements may help improve strength and muscle mass.
Eat plenty of fruits and vegetables. Fruits and vegetables are packed with nutrients that help your muscles grow strong and stay healthy. such as vitamins, minerals, and antioxidants.
Avoid processed foods. Processed foods are often high in calories and low in nutrients, which can contribute to weight gain and muscle loss.
Benefits of Lean Body Mass
Increasing your lean body mass offers many health and performance benefits.
1. Increased Strength and Power
Lean body mass (LBM) is the main source of strength and power in the human body. Muscle fibers, which make up most of LBM, can contract to produce force, letting you move in many ways, like lifting weights or running fast. As your LBM increases, you get better at lifting heavier things, running faster, jumping higher, and doing everyday tasks easier.
2. Improved Metabolism
LBM is metabolically active, meaning it burns calories even at rest. The activity of your muscles uses up calories throughout the day, even when you're not exercising. Individuals with higher LBM tend to have higher resting metabolic rates, leading to increased calorie burning throughout the day, which is very beneficial.
3. Reduced Risk of Obesity and Other Chronic Diseases
LBM plays a crucial role in maintaining a healthy weight and reducing the risk of chronic diseases. By increasing your LBM, you can:
Regulate blood sugar levels: muscle tissue helps absorb glucose from the bloodstream, promoting better blood sugar control and reducing the risk of type 2 diabetes.
Lower blood pressure: LBM can positively influence blood pressure levels, reducing the risk of hypertension and cardiovascular diseases.
Optimize cholesterol levels: LBM can influence cholesterol levels by increasing HDL (good) cholesterol and decreasing LDL (bad) cholesterol, reducing the risk of heart disease and stroke.
4. Mental and Emotional Health
Maintaining a healthy body composition, including a high proportion of LBM, can contribute to positive mental and emotional well-being. Studies have shown that individuals with higher LBM tend to have:
Enhanced self-esteem: Improved physical fitness and body image can boost self-esteem and confidence.
Reduced depression and anxiety: Physical activity and a healthy body composition can alleviate symptoms of depression and anxiety.
5. Improved Bone Health
Strong muscles help keep bones strong and reduce the risk of osteoporosis, a condition that makes bones weak and brittle. Muscles produce hormones that help build bones and prevent them from breaking.
6. Enhanced Immunity
LBM contributes to a robust immune system by supporting the production of white blood cells, the body's primary defense against infections. Adequate LBM levels ensure that the immune system has the resources it needs to protect the body from pathogens.
Conclusion
Determining ideal lean body mass levels is an important assessment for overall health and fitness. Methods like DEXA scans and underwater weighing provide accurate evaluations, while equations based on easily measured variables also give reasonable estimates.
Comparing your numbers to normal ranges categorized by age and gender allows you to quantify potential improvements. On average, men have around 120–150 lbs of LBM, and women have 90–110 lbs. But athletes and more muscular individuals can reach higher levels.
The many benefits of building lean mass include increased strength, elevated metabolism, enhanced bone density, and reduced risks of chronic diseases. So it becomes a key variable to measure and maximize through proper resistance training, nutrition, and recovery protocols.
While some muscle loss is certain with aging, much can be prevented through consistent exercise. Tracking metrics like waist size and grip strength over time also gives feedback on maintaining or expanding lean mass.
Remember, lean body mass represents everything in your body except fat. So optimizing this number relative to fat mass offers the best health and performance outcomes, both in the short and long run.
Frequently Asked Questions
What makes up lean muscle mass?
Lean body mass (LBM) is made up of the combined weight of your bones, muscles, organs, ligaments, and tendons, plus all the water in your body.
What is the difference between lean and bulk?
Building lean muscle focuses more on high-intensity, lower-volume workouts, while muscle bulk requires heavy lifting and high-volume training.
What happens when you lose lean muscle mass?
You'll become less efficient at burning calories, possibly increasing your body fat.
What is the ideal lean muscle mass percentage?
A good lean muscle percentage range should be about 70% to 90% to be considered healthy.
Does Height Affect Lean Body mass?
Yes, height can affect lean body mass (LBM). Taller people generally have more LBM than shorter people because they have more muscle and bone tissue.
Does your lean body mass change?
Yes, your lean body mass (LBM) can change throughout your life due to factors like age, nutrition, exercise, hormones, and disease.