Is having a lot of muscle unhealthy? Unpacking the health impacts of muscle mass

September 27, 2025 •

4 min read

Extensive research, including a key study in The American Journal of Medicine, has shown that higher muscle mass is correlated with a lower risk of death in older adults, suggesting a significant link to longevity. This challenges the question: is having a lot of muscle unhealthy?

Quick Summary

For those with a naturally developed, healthy body composition, increased muscle mass is generally a strong indicator of good health and longevity. However, issues arise from extreme levels of muscle mass obtained through unhealthy methods, such as performance-enhancing drugs (PEDs), or when it compromises a person's cardiovascular system and joints due to excessive weight, whether muscle or fat.

Key Points

Natural vs. Unnatural: Naturally gained muscle mass is generally a strong sign of health, while unnaturally high mass achieved through PEDs poses significant risks.
Heart Strain: Excessive, unnaturally large muscle mass can overwork the heart, which does not grow proportionally to the body's size.
Joint Stress: Carrying extreme body weight, whether muscle or fat, can lead to chronic joint strain and other musculoskeletal problems over time.
Overtraining Risks: Even without drugs, excessive training can lead to conditions like rhabdomyolysis, which can cause severe kidney damage.
Muscle Quality Matters: The health benefits of muscle are also tied to its quality (composition) and functionality, not just its quantity.
Longevity Link: Maintaining healthy muscle mass is strongly correlated with a longer, healthier life and is a better health indicator than BMI.

The Health Benefits of Natural Muscle Mass

Far from being unhealthy, a healthy amount of muscle mass is a cornerstone of good health, offering numerous systemic benefits. It's a metabolically active tissue, meaning it burns calories even at rest, which can aid in weight management and improve overall metabolic function. The health advantages include:

Improved Metabolic Health: Increased muscle mass enhances insulin sensitivity, helping to regulate blood sugar levels and significantly lowering the risk of developing type 2 diabetes.
Stronger Bones: Resistance training, which builds muscle, is also proven to increase bone density, reducing the risk of osteoporosis and fractures, especially as we age.
Enhanced Mobility and Balance: Strong muscles are essential for functional strength, supporting daily activities like walking and climbing stairs. This prevents frailty and reduces the risk of falls in older adults.
Better Heart Health: Regular strength training improves circulation, lowers 'bad' LDL cholesterol, and increases 'good' HDL cholesterol, promoting a healthy cardiovascular system.

When Does Muscle Mass Pose a Risk?

The idea that too much muscle is inherently unhealthy is a significant oversimplification. The real risk factors are almost always tied to the means by which that muscle was acquired or the sheer extreme level of body mass being carried. For the vast majority of people, naturally building muscle through consistent training and proper nutrition is overwhelmingly beneficial.

The Dangers of Extreme Muscle Mass and PEDs

Problems emerge when individuals push their bodies to unnatural limits, typically with the use of performance-enhancing drugs (PEDs) like anabolic steroids. This is a crucial distinction that separates the average, healthy lifter from a professional bodybuilder. The health risks associated with such extreme practices are severe and well-documented:

Cardiovascular Strain: The heart, a muscle itself, must work significantly harder to pump blood to a body carrying an extreme amount of muscle mass. The heart's size does not increase in proportion to the rest of the body's muscle, leading to inefficiency and potential cardiac events. PEDs can also directly cause heart damage.
Organ Damage: Steroid use and other unhealthy practices can cause significant stress on the liver, kidneys, and other internal organs.
Hormonal Imbalances: PEDs disrupt the body's natural hormone production, leading to a cascade of side effects.

Excessive Body Mass and Joint Strain

Regardless of whether the weight is muscle or fat, carrying an extremely high body mass puts significant strain on the joints and skeletal system over time. For professional strongmen and bodybuilders who maintain immense weight, this can lead to chronic issues like arthritis and joint pain.

Natural vs. Unnatural Muscle Gain: Health Outcomes

To better understand the difference, consider the table below comparing the health trajectories of natural, healthy muscle gain versus unnaturally high muscle mass.


Aspect	Natural Muscle Gain (Healthy)	Unnatural Muscle Gain (Extreme)
Method	Consistent resistance training, balanced nutrition, sufficient rest.	Intense training combined with performance-enhancing drugs (PEDs).
Health Impact	Significant improvements in cardiovascular, metabolic, and bone health.	High risk of cardiovascular events, organ damage, and hormonal issues.
Effect on Joints	Strengthens joints and connective tissues, preventing age-related decline.	Causes significant, long-term strain on joints and the skeletal system.
Physical Appearance	Firm, functional musculature; balanced and proportionate physique.	Exaggerated, disproportionate muscle mass; often associated with negative side effects.
Longevity	Associated with increased lifespan and lower mortality risk.	Linked to a higher risk of early mortality due to cardiac and organ strain.

The Problem with Overtraining

Even without PEDs, improper training can lead to health problems. Pushing the body past its limits consistently is known as overtraining, and it can cause a range of issues:

Rhabdomyolysis: This is a serious condition where damaged muscle tissue breaks down and releases proteins into the bloodstream. These proteins can harm the kidneys and lead to kidney failure.
Increased Resting Heart Rate: Instead of strengthening the heart, overtraining can stress the cardiovascular system, paradoxically increasing your resting heart rate.
Chronic Fatigue and Weakness: The body needs rest to repair and grow. Without sufficient recovery, performance declines, and you may experience persistent fatigue and weakness.
Hormonal Disruption: Overtraining can raise cortisol (the stress hormone) levels while suppressing others, negatively impacting your mood and immune system.

Focus on Muscle Quality, Not Just Quantity

Beyond simply gaining mass, modern health science emphasizes the importance of muscle quality. A 2021 study in PubMed found that metabolically healthy individuals had higher-quality muscles (less fat infiltration) than metabolically unhealthy individuals, even with similar muscle mass levels.

This highlights that functionality and health are more important than size alone. For most people, the goal should be to build and maintain healthy, functional muscle mass through sustainable habits. Prioritizing resistance training, a balanced diet, and adequate rest will provide a wealth of health benefits without the risks associated with extreme, unnatural growth.

Conclusion: The Final Verdict

In summary, the question of whether having a lot of muscle is unhealthy is not a simple yes or no. For the vast majority of people who build muscle naturally, a higher muscle mass is a clear indicator of better overall health and a longer life. The dangers are concentrated among a small minority who pursue extreme and unnatural body compositions, often involving drugs, which can place dangerous stress on the heart, joints, and organs. A balanced approach focusing on healthy, functional strength and muscle quality is the key to reaping the benefits of a muscular physique for a lifetime.

Frequently Asked Questions

Not necessarily. While a healthy amount of muscle is beneficial, extreme, unhealthy muscle mass (often from drug use) or disproportionate muscle gain that strains the body can be detrimental. The quality and function of the muscle are key, not just the size.

Yes, but primarily in cases of extreme, unnaturally large muscle mass. A heart that has to pump blood to a massive amount of muscle tissue can become overworked. This is a common risk for professional bodybuilders who use performance-enhancing drugs, not for average, healthy lifters.

Yes, genetics and hormones limit how much muscle a person can build naturally. For most people, these natural limits prevent them from reaching a size that would be detrimental to their health, provided they follow safe training practices.

Healthy muscle is typically gained over time through a balanced approach to exercise and nutrition, resulting in a proportionate and functional physique. Unhealthy, extreme muscle mass is often gained rapidly, sometimes with drugs, and can lead to a disproportionate body that may compromise health and mobility.

The biggest health risks for bodybuilders, especially those who use steroids to achieve extreme size, include cardiovascular complications, kidney damage, liver problems, and significant joint and skeletal strain from carrying excessive weight.

Yes, but this highlights the limitations of BMI. A very muscular person may have a high BMI that classifies them as overweight or obese, even though they have a low body fat percentage. A better indicator of health is body composition, which measures the ratio of muscle to fat.

No, when done with proper form and a sensible training plan, resistance training actually strengthens joints and connective tissue. However, lifting with improper form, using excessive weight, or carrying extremely heavy body mass can lead to joint problems over time.