Maintaining lean muscle mass is a cornerstone of long-term health, functional independence, and even longevity. From our early adult years through old age, muscle tissue plays critical roles. It supports our skeletal frame, drives our metabolism, and enables every movement we make. Yet many people overlook the importance of preserving and building muscle until problems arise. This article explores why lean muscle matters for the general public, competitive athletes, aging adults, and fitness professionals alike, and how to nurture muscle health through the years.

Lean Muscle Mass: A Key to Health and Longevity

Lean muscle is far more than “bulk” for bodybuilders. It’s a metabolically active tissue that helps regulate blood sugar, supports joint health, and maintains our ability to perform daily tasks. Strong evidence links muscle strength with better health outcomes. A University of Michigan study found that people with very low muscle strength were about 50% more likely to die prematurely than those who were stronger. Muscle and longevity go hand in hand. Greater muscle strength is associated with a lower risk of mortality and a higher likelihood of aging independently. More muscle means you can move confidently, avoid falls, and remain active as you get older.

Muscles also act as “active engines” in our body’s metabolism. Even at rest, muscle tissue burns more calories than fat does, which helps with weight management and metabolic health. This is why having a higher proportion of lean body mass can improve your baseline metabolism and reduce the risks of obesity or diabetes. For the general public, maintaining muscle supports everyday energy levels and makes it easier to maintain a healthy weight. Athletes rely on muscle for performance, as strength and power are built on well-conditioned muscle fibers. And for aging adults, muscle becomes a sort of insurance policy for staying mobile and independent.

Age-Related Muscle Loss and How to Stop It

It’s often said in fitness, “use it or lose it,” and that definitely applies to muscle. As we age, a natural decline in muscle mass, known as sarcopenia, begins to take its toll. After about age 30, adults who aren’t regularly strength training can lose roughly 3% to 5% of their muscle mass per decade. Over a lifetime, an inactive person might lose around one-third of their muscle. This loss of muscle results in greater weakness and reduced mobility, which can increase the risk of falls and injuries in older adults. If you’ve noticed an elderly person having trouble standing up or climbing stairs, much of that comes down to dwindling muscle strength. The good news is that muscle loss prevention is possible. Age-related muscle wasting is not inevitable if you take action.

So, how to stop muscle wasting as you get older? The two main strategies are staying active and ensuring proper nutrition. Regular physical activity signals your body to preserve and even build muscle tissue. In contrast, being sedentary accelerates muscle loss. Diet plays a role too; since muscles are made of protein, getting enough high-quality protein helps support muscle maintenance. Many people in their 60s, 70s, and beyond have successfully rebuilt muscle through weight training and maintained their strength into their later years. The human body retains an amazing capacity to adapt. If you consistently challenge your muscles, they will respond by maintaining or increasing in size. The key to muscle loss prevention is a proactive approach: don’t wait until you’ve lost a lot of strength to start working on it.

The Strength Training Benefits for All Ages

If lean muscle is the goal, strength training benefits are the means to achieve it. Strength training refers to exercises that make your muscles work against a force. This kind of exercise is crucial for building and maintaining muscle at any age. Research supported by the National Institute on Aging has identified multiple advantages of strength training in later years, including maintaining muscle mass, improving mobility, and even increasing the healthy years of life. Lifting weights doesn’t just make you stronger. It helps you stay active longer and can enhance your quality of life as you age. For older adults specifically, resistance training for seniors can combat weakness and frailty. Studies show that even individuals in their 70s and 80s can improve muscle strength and size through regular resistance workouts. The benefits extend beyond the muscles, too. Stronger muscles mean better balance and coordination, which reduces fall risk. Strength training also helps preserve bone density, lowering the risk of fractures.

Building Muscle Over 40: It’s Never Too Late

Many people in their 40s and beyond worry that it’s too late for them to get strong or fit. The reality is that building muscle over 40 is absolutely achievable. It may be one of the most important times to do so. Around our mid-30s to 40s, age-related changes like slowing metabolism and hormonal shifts can make it easier to gain fat and harder to maintain muscle. This makes strength training and muscle-focused fitness especially valuable in midlife. The good news is that your muscles can still respond and grow; the process might be a bit slower than for a 20-year-old, but consistent training yields significant improvements. For example, men in their 50s and 60s who follow a structured weight training program for several months have been shown to increase their lean muscle mass and strength noticeably. If you’re starting from scratch at 45 or 50, you might actually see rapid gains initially as your body adapts to exercises it hasn’t done before.

Measuring Body Fat and Lean Muscle in Your Fitness Journey

As you work on improving your body composition, it’s important to have ways to measure progress beyond just the bathroom scale. Traditional body fat measurement methods include:

• Skinfold Calipers (Pinch Tests): A trained practitioner pinches specific sites to evaluate thickness and uses those readings to estimate overall fat levels. This technique allows you to track changes in targeted areas, making it useful when monitoring long-term improvements from strength training or nutrition adjustments. Although the method requires consistency in technique, regular measurements taken at the same locations offer reliable insight into how your body composition is shifting.

• Tape Measurements: By measuring areas such as the waist, hips, arms, and thighs, you get a clearer picture of how your shape evolves over time. This method highlights progress that scales often overlook, especially when muscle gain offsets fat loss. Consistent measurement practices, including using the same tape and keeping tension steady, ensure more accurate comparisons that reflect real improvements in performance, physique, and overall fitness.

• Bioelectrical Impedance Scales: These use a mild electrical signal to estimate fat levels, muscle mass, and hydration status, giving you a broader view of internal changes. These devices are quick to use and provide data that helps you connect daily habits with measurable outcomes. Although readings can vary depending on factors like hydration, consistent testing conditions improve accuracy. These scales reveal helpful trends that show whether your training, recovery, and nutrition strategies are moving you closer to your body composition goals.

There are even online tools or formulas, sometimes dubbed a muscle weight calculator, that estimate how much muscle mass you have or could potentially gain. These calculators often use inputs such as your height, weight, and possibly limb circumferences to estimate your muscle distribution.

For a truly detailed look at your body composition, nothing beats advanced scanning technologies. The gold standard in body composition analysis is the DEXA scan. A body composition DEXA scan (Dual-Energy X-ray Absorptiometry) can directly measure how much of your body is fat, lean mass, and bone. Originally developed to measure bone density, DEXA machines today provide a comprehensive report of your body’s makeup, unlike stepping on a scale, which only provides total weight. A DEXA scan can reveal, for instance, that you have 30 pounds of fat, 110 pounds of lean mass, and 7 pounds of bone, along with detailed percentages. This is incredibly useful for anyone on a fitness or weight loss journey, as it indicates whether weight changes are due to fat loss or muscle gain or loss.

The DEXA Advantage: Precise Body Composition Tracking

A DEXA body composition scan provides an in-depth snapshot of your body's health that can be eye-opening for fitness enthusiasts and beginners alike. During a DEXA scan, you lie on a table while a machine scans your body using two very low-dose X-ray beams. It’s painless and typically takes about 5 to 10 minutes. The technology is sophisticated: the dual X-ray energies allow the scanner to distinguish between bone, lean tissue, and fat tissue. The DEXA scan scale is calibrated to subtract out the dense weight of your bones, then measure what’s left as either muscle or fat. The result is a detailed breakdown, often including segmental analysis, your body fat measurement as a percentage, your visceral fat level, and your bone density. Because of its high precision, a DEXA scan is widely considered the most reliable method for assessing body composition. For someone serious about tracking strength training benefits or weight loss progress, it provides clear data that you simply can’t get from looking in the mirror or reading a scale.

There are a few considerations with DEXA scans. One is accessibility. You usually have to go to a clinic or a specialized facility to get one. The other is the DEXA scan cost, which typically ranges from about $50 to $150 per scan, depending on your location and provider. This cost means DEXA isn’t something most people will do every week, but many find it affordable enough to do a few times a year. You might get a scan at the start of a fitness program, then a follow-up 3 months later, and so on, to objectively measure changes in lean body mass and fat. Some facilities, such as BOD in Los Angeles, even offer subscription packages or discounts for regular scans, making it easier to incorporate into your routine. Another consideration is minimal radiation exposure – DEXA uses X-rays, but at a very low dose. It’s generally considered safe. However, it is not recommended for pregnant women as a precaution.

For those serious about their health data, a DEXA scan is basically a health scan for fitness progress. It provides concrete numbers that can motivate you and guide your training or nutrition adjustments. Say you discover via DEXA that your right leg has slightly less muscle than your left, you might add some unilateral exercises to balance your strength. Or, if you find that you have higher visceral fat, that could encourage dietary changes to reduce this risk factor. Seeing your muscle mass increase on a report can be extremely validating when you’ve been working hard in the gym. It puts numbers to the phrase “stronger than yesterday.” Leveraging tools like DEXA scans alongside your training can help ensure that as you lose weight or gain muscle, you know exactly what’s happening inside your body. It takes the guesswork out of “am I making progress?” and replaces it with actionable data. By periodically getting a body composition DEXA scan, you can adjust your program to reach your goals better.

Muscle truly is a “use it or lose it” asset. The effort you invest in maintaining and building muscle throughout life will pay you back many times over in the form of better health, functionality, and vitality. From young adulthood into our senior years, strong muscles help us move freely, support our metabolism, protect our bones, and even influence how long and well we live. Whether you’re a 30-year-old looking to stay fit, an athlete pushing for peak performance, or a retiree aiming to remain independent, keeping and improving your muscle mass should be a top priority. The beauty is that it’s never too late to start. With regular strength training, adequate nutrition, and innovative use of tracking tools, you can make significant improvements in muscle strength at any age.

 

Sources:

• Harvard Health Publishing – “Preserve your muscle mass”

• University of Michigan School of Public Health – “People with Low Muscle Strength More Likely to Die Prematurely”

• National Institute on Aging – “How can strength training build healthier bodies as we age?”

• Weigh to Wellness – “5 Best Body Composition Tests for Weight Loss”