Benefits of Lean Body Mass and How to Build Muscle

Written by: Ryah Nabielski, MS, RDN

Skeletal muscle is the largest organ in the body, and it’s essential for more than strength and mobility. Your muscle strength and lean body mass help determine your overall health. Muscles impact hormone levels, metabolic function, body composition, and more. Often referred to as the “organ of longevity,” your muscles help you live longer while maintaining your health.

If you’re a fan of Hannah Bower and Twenty2 Nutrition, you already know that exercise is key for your muscular health. And more, it improves your confidence and how you feel. Even small amounts of movement built into your routine work at a cellular level to improve your overall health. 

Today’s article will dive into the benefits of a healthy muscle mass and how to maintain or improve muscular health. We’ll cover: 

  • The science of muscles
  • Benefits of strong muscles
  • Age-related muscle loss
  • How to gain and maintain muscle mass

Let’s dive in! 

Muscle Science

There are three types of muscles: skeletal, cardiac, and smooth. Cardiac muscles make your heartbeat, and smooth muscles operate blood vessels, the digestive system, and other automatic movements. 

Skeletal muscles – our focus today – attach to bones and facilitate voluntary movement. Muscle contractions cause movement. Your muscles also stop movement and help you maintain your posture, stabilize your pelvic floor, and more. 

Skeletal muscle cells contain many mitochondria (which increase as you build muscle and improve fitness). Mitochondria are the tiny parts of your cells (organelles) that turn calories into energy. 

Your muscles account for around 40% of your body weight (lean body mass) and contain 50 to 75% of all body proteins. The balance between muscle breakdown and muscle building (synthesis) determines your muscle mass. Your muscles are frequently degrading and regenerating; the regeneration rate is higher when you are younger.  

This balance has a lot to do with your health and habits; injuries, disease, nutritional status, hormone balance, and other factors influence it. 

Benefits of Muscle Mass

There is a long list of the benefits of healthy muscle mass and strength. Good body composition at any age or weight is more important than your weight for metabolic and overall health. 

The benefits of strong muscles include: 

  • Reduced injuries; better recovery from injuries
  • Improved glucose and insulin (i.e., better blood sugar balance)
  • Better bone health 
  • Improved mobility and movement
  • Better sleep
  • Improved brain health, including mood and cognition
  • Improved body composition 
  • Less pain with pregnancy
  • Improved energy
  • Slower aging

Let’s look at some of these benefits in more detail. 

Glucose and Insulin 

Muscles are the largest site in the body for glucose metabolism; glucose enters muscle cells, where it’s turned into energy. The skeletal muscles take in 80% of glucose after meals, making muscles essential for metabolic health. 

Exercise allows your muscles to take in glucose without insulin (the hormone that helps with glucose uptake). Better skeletal muscle health means better blood sugar balance and insulin sensitivity, which can help prevent diabetes and metabolic disease. 


Your muscles, bones, and joints work together for movement. Together, they are the musculoskeletal system, and the tissues are constantly communicating. It’s no wonder that improved muscle mass strengthens your bones and joints. It helps improve the loss of bone that occurs with age.


In our modern world, poor sleep is epidemic and reduces protein synthesis. Not sleeping enough or getting fragmented sleep (hello, new moms) makes it hard to maintain and build muscle since this happens during sleep. Poor sleep can also make it difficult to recover from exercise. 

Conversely, when you get quality sleep for 7-9 hours nightly, it’s easier to build muscle, improve strength, and recover from exercise effectively. Sleep is good for hormone balance, metabolic health, and other factors contributing to healthy muscles. 

Mood and Cognition

Through your own experiences, you’ve likely discovered that physical health benefits mental health and improves brain function. So, it’s unsurprising that important interactions between the muscle and the brain exist. Good muscle health supports healthy moods and cognition, while impairments in muscle homeostasis impact brain health. 

Muscle Loss with Age

Once you build muscle in your younger years, you begin losing it around age 40. You’ll lose an average of 8% of muscle mass per decade until age 70. After that, muscle loss accelerates to a rate of 15% per decade. As you lose muscle, you may gain fat, even if the scale weight stays similar. 

Sarcopenia is the natural loss of muscle mass and strength with age. Sarcopenia is different than muscle wasting, which occurs with chronic disease. Still, it is associated with fragility, poor quality of life, loss of mobility, developing chronic diseases (like heart disease and diabetes), and death from all causes. 

Maintaining and improving muscle mass can help prevent or slow these changes. 

Along with advancing age come physical and lifestyle changes that affect muscle loss, including:

  • Reduced physical activity 
  • Hormonal changes, including declining testosterone and growth hormone
  • Changes in appetite and nutrition 
  • Increased oxidative stress

How to Gain Muscle 

It’s never too early or too late to pay attention to muscle health and work toward healthy muscle mass and increased strength. When you start early, you head into midlife with more mass to support your health, but you can maintain your muscle and even grow more in every decade of life. 

Three strategies will help you with your goals: strength training, dietary protein, and supplements. 


Strength training does more for muscle mass and strength, whereas endurance training (cardio) supports endurance and cardiovascular fitness. Strength training increases the hormones required for building proteins. It also improves mitochondrial function, making your muscle metabolize more efficiently over time, effectively increasing your metabolic rate. 

You can see muscle gains with just three 30-minute sessions per week, with resistance increasing over time. Try to fatigue each muscle group at least twice per week. If you are just beginning, start with body weight exercises. Hannah Bower is the one to follow for more guidance here. 


You need enough protein in your diet to build the proteins that form your muscles. Without enough protein, you’ll notice you stall at muscle growth or even lose muscles. Along with strength training, good nutrition is necessary.

How much protein do you need? The truth is that it’s probably more than you think and is highly individual based on your body size, health status, goals, and other factors. Read the details in All About Protein – How Much You Need

For many adults, working toward 30 grams of protein with each of your three daily meals will give you a good start and push your muscles into building mode.  

Good sources of protein include:

  • Grass-fed beef, bison, wild game
  • Pasture-raised chicken and pork
  • Pastured eggs
  • Grass-fed dairy products
  • Sustainable fish and seafood
  • Organic soy (tofu, tempeh, edamame)
  • Beans, nuts, seeds
  • High-quality protein powders

Protein isn’t the only dietary component that supports muscle growth, but it’s essential. It’s also important to optimize fiber, antioxidants, iron, vitamin D, and other nutrients. 


Two supplements stand out in the research for muscle growth, strength, and recovery benefits: whey protein and creatine. 

Whey protein is a complete protein containing optimal levels of the branched-chain amino acids required for muscle structure. Research demonstrates whey protein supplements promote lean muscle growth, maintenance, and recovery. 

If you tolerate whey protein (dairy) well, Twenty2 Nutrition Grass Fed Whey Protein is the best choice for these benefits. If you don’t tolerate dairy or include it in your diet, Collagen-Egg Protein and Vegan Protein contain complete amino acid profiles to help meet your daily protein needs and support muscle health. Each of these proteins has other health benefits, so one strategy can be to rotate your protein powders. 

Creatine is a naturally occurring protein-like molecule concentrated in the muscles that recycle ATP (energy) through the mitochondria. Improving creatine levels through supplementation helps improve muscle strength and lean body mass. Also, it reduces muscle damage from resistance training.  

It’s one of the most studied supplements, and new research suggests creatine benefits beyond muscles, supporting brain health, sleep, and blood sugar management. 

Twenty2 Nutrition Creatine Complex adds HMB (beta-hydroxy-beta-methylbutyrate), a derivative of the amino acid leucine, to support muscle retention along with two forms of creatine: creatine monohydrate and magnesium creatine chelate. Read Creatine Supplement FAQs for more details on this effective combination. 

How you care for your muscles now will support your health and longevity into the future. Support optimal lean body mass and improved muscle strength with simple strategies, including strength training and eating protein. For more support, use targeted supplements like whey protein and creatine to help you reach and maintain your goals. 

This article is for educational purposes only and is not intended as a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or another qualified healthcare provider before changing your diet or beginning a new supplement, especially if you are pregnant or breastfeeding, take medication, or have a medical condition. 

Ryah Nabielski, MS, RDN is a Registered Dietitian, functional nutritionist, writer, and recipe creator. Ryah helps clients use a natural, food-as-medicine approach to improve fertility, pregnancy, hormone balance, autoimmunity, and discover a healthy relationship with food and body. Learn more about Ryah and her private practice at