Muscle Is an Organ of Longevity: Why Women Need to Protect It as They Age

Quick Answer

Muscle is about far more than looking toned or being able to lift heavy weights. Skeletal muscle helps us move, maintain balance, use glucose, support our metabolism and remain physically independent. It also behaves like a secretory organ, releasing signalling molecules called myokines that can communicate with other tissues throughout the body.

As we get older, maintaining muscle mass, strength and function becomes increasingly important. This is particularly relevant for women through midlife and beyond, when age-related changes, hormonal transitions and reduced physical activity can all influence muscle health.

Research consistently links greater muscular strength and regular muscle-strengthening activity with better health outcomes, although observational associations with longevity cannot prove that muscle itself directly causes a longer life. The encouraging part is that muscle remains remarkably responsive to training throughout life. You are not too old to become stronger. And you do not need to become a bodybuilder to benefit.

What You Will Learn

• Why skeletal muscle is much more than a movement organ.
• What muscle has to do with longevity.
• What myokines are and why scientists are interested in them.
• Why women gradually lose muscle as they age.
• What sarcopenia actually means.
• Why menopause can be an important time to prioritise strength.
• How muscle influences metabolism, bones, balance and independence.
• Why strength may sometimes matter more than simply having more muscle.
• How resistance training protects muscle.
• The role of protein, recovery and everyday movement.
• Why it is never too late to start becoming stronger.

Introduction: We Need to Change the Way Women Think About Muscle

For decades, women have received an extraordinary amount of advice about making their bodies smaller. Lose weight. Eat less. Burn calories. Tone up. Avoid becoming bulky.

But as we learn more about healthy ageing, a very different conversation is emerging. Perhaps one of the most valuable things a woman can protect as she gets older is not how little she weighs. It is how much strength and physical capacity she retains.

Because muscle is not simply something we see in the mirror. It is the tissue that helps you stand up from a chair without thinking about it. Carry your shopping. Climb a flight of stairs. Lift a suitcase. Get down onto the floor and back up again. Walk confidently. Catch yourself if you stumble. Play with children or grandchildren. Continue travelling, gardening, working and living independently.

We often do not appreciate these abilities while they are easy. But maintaining them is one of the foundations of ageing well. And muscle has another fascinating role that we are only beginning to appreciate fully. It communicates with the rest of the body. So rather than thinking about muscle as something belonging to athletes or bodybuilders, it may be more useful to think of it as an important organ of healthy ageing.

What Is Skeletal Muscle?

Skeletal muscle is the muscle attached to your bones that allows you to move voluntarily. When you walk, lift something, climb stairs or turn your head, your skeletal muscles contract to create movement. But that is only part of their job.

Skeletal muscle also plays important roles in glucose metabolism, energy expenditure, amino acid storage and metabolism, physical function, balance and stability, heat production and communication with other tissues. Muscle is metabolically active tissue. That means it is not simply sitting beneath the skin waiting for you to exercise. It is participating in your physiology every day.

Why Are Scientists Calling Muscle an Organ?

We traditionally think of organs as things such as the heart, liver or kidneys. Muscle looks different because it is distributed throughout the body. But scientists increasingly recognise skeletal muscle as an endocrine and secretory organ.

When muscles contract, they can release signalling proteins and peptides known collectively as myokines. These molecules can act locally within muscle or communicate with other tissues. Research is exploring how myokines interact with processes involving metabolism, inflammation, blood vessels, the immune system, bone and the nervous system.

This does not mean flexing your biceps releases a magical longevity hormone. The biology is far more complicated. But it does fundamentally change the way we should think about muscle. Muscle is not only machinery for movement. It is biologically active tissue communicating with the rest of your body.

Muscle and Longevity: What Does the Research Actually Show?

A systematic review and meta-analysis involving almost two million adults found that higher muscular strength, including handgrip strength, was associated with lower all-cause mortality. Similarly, systematic reviews examining muscle-strengthening activity have found associations with lower risks of all-cause mortality and several major non-communicable diseases.

More recently, a 2026 analysis of three large prospective cohorts, including more than 147,000 people and predominantly women, found that moderate amounts of long-term resistance training were associated with lower all-cause mortality. The lowest risks were seen when resistance training and aerobic activity were considered together.

But there is an important distinction. These findings do not prove that building muscle directly makes you live longer. People who strength train may differ in many other ways from people who do not. So rather than saying more muscle equals a longer life, a more scientifically accurate conclusion is: muscular strength and muscle-strengthening activity are important markers and components of healthy ageing and are consistently associated with better long-term health outcomes. That is still a powerful message.

Muscle Mass and Muscle Strength Are Not Exactly the Same Thing

Having more muscle mass does not automatically mean having greater functional strength. And as we age, strength can decline faster than muscle mass. That is why modern definitions of sarcopenia place considerable importance on muscle strength and physical performance, not simply the amount of muscle someone has.

For healthy ageing, the question is not only how much muscle I have, but also what can my body actually do? Can you rise comfortably from a chair? Carry something heavy? Climb stairs? Maintain your balance? Walk at a reasonable pace? Recover if you stumble? Those abilities matter enormously in everyday life.

What Is Sarcopenia?

Sarcopenia refers to the progressive loss of muscle strength, muscle quantity or quality and physical performance associated with ageing. It is not simply getting a bit weaker. In its more advanced form, sarcopenia can significantly affect mobility, independence and quality of life.

Age is an important contributor, but it is not the only one. Muscle loss can also be influenced by physical inactivity, illness, inadequate nutrition, low protein intake, hormonal changes, chronic inflammation, neurological changes and periods of bed rest or hospitalisation. This is why maintaining muscle is a lifelong project rather than something to start worrying about only in old age.

Why Midlife Matters

A review highlighted 40 to 50 years as an important period for maintaining strength and interrupting a downward cycle of decline, while later life places increasing importance on preserving strength, balance and independence. It also identified menopause as one of the life transitions when muscle function and activity patterns may change.

This makes midlife an opportunity, not a deadline. You do not need to wait until weakness becomes noticeable before doing something about it.

Menopause and Muscle

For women, the menopause transition adds another layer to the conversation. Oestrogen receptors are present in skeletal muscle, and researchers continue to investigate how declining ovarian hormones influence muscle protein turnover, muscle quality, strength and recovery.

But menopause does not happen in isolation. Around the same period, women may also experience changes in sleep, reduced activity, changes in body composition, increased caring or work responsibilities, stress, changes in dietary habits and loss of previous exercise routines. All of these can influence muscle.

What we can say confidently is that midlife is an excellent time for women to become more deliberate about maintaining muscle and strength. And that does not mean trying to recreate the body you had at 25. It means building the physical capacity you want at 60, 70 and beyond.

Muscle Is Your Movement Reserve

One way to think about muscle is as a physical reserve. Imagine two women entering their seventies. Both experience an illness that leaves them inactive for several weeks. One entered that period with good muscle strength, regular resistance-training habits and strong physical function. The other was already close to the threshold where everyday activities felt difficult.

Both may lose strength during inactivity. But the woman who began with greater physical reserve has further to fall before basic tasks become challenging. This is one reason building and maintaining capacity before you urgently need it matters. You are not training only for today's workout. You are building reserve for your future self.

Muscle and Metabolic Health

Skeletal muscle also has an important relationship with glucose metabolism. After we eat carbohydrates, glucose enters the bloodstream. Insulin helps signal tissues to take up and use or store that glucose, and skeletal muscle is an important site for glucose disposal. Physical activity and muscle contraction can also influence glucose uptake.

This is one reason resistance exercise can be valuable for metabolic health. Diet, body composition, genetics, sleep, activity levels and overall health all contribute. But metabolically active muscle is an important part of that system.

Muscle and Bone: A Partnership Worth Protecting

Muscle and bone do not operate independently. Every time a muscle contracts against resistance, it creates mechanical forces that act on bone. Weight-bearing and resistance activities are therefore important components of maintaining musculoskeletal health.

This becomes particularly relevant for women as we age because bone density can decline more rapidly around and after menopause. Maintaining muscle strength, balance and physical function also matters because it may help reduce the likelihood and consequences of falls. For older adults, NHS guidance specifically recommends activities that improve strength, balance and flexibility on at least two days each week.

Muscle and Independence

Longevity is not simply about the number of birthdays you reach. It is about healthspan. How many of those years can you spend doing the things that matter to you? The ability to live independently depends partly on surprisingly ordinary movements: getting out of bed, standing from the toilet, stepping into the shower, carrying groceries, walking outdoors, using stairs, lifting objects onto shelves and getting up after sitting on the floor.

These movements require strength. When we say muscle matters for longevity, this is what we really mean. Not bigger biceps. Capability.

Why Women Should Not Be Afraid of Strength Training

Resistance training simply means asking your muscles to work against resistance. That resistance could come from dumbbells, barbells, weight machines, resistance bands, your own body weight, kettlebells or everyday heavy objects. The goal is not to look like a bodybuilder. The goal is to give your muscles a reason to remain strong.

How Much Strength Training Do We Need?

You do not need to spend every day in the gym. UK and WHO physical activity guidance recommends muscle-strengthening activity involving the major muscle groups on at least two days each week. For older adults, strength work should sit alongside aerobic activity, everyday movement and, particularly later in life, balance-focused activity.

If you are completely new to resistance training, start appropriately. Two well-structured sessions each week can be meaningful. Consistency matters far more than creating the most complicated programme imaginable.

What Should Strength Training Actually Feel Like?

For muscle to adapt, it needs to be challenged. A useful programme generally includes movements that train the major muscle groups and become progressively more challenging as you become stronger. This principle is known as progressive overload. It could mean gradually increasing the weight, increasing repetitions, increasing resistance, improving your range of movement, performing a more challenging variation or improving technique and control. Think in months and years, not days.

Do You Need a Gym?

Absolutely not. You can become stronger using resistance bands, dumbbells or body-weight movements at home. The NHS includes activities such as carrying heavy shopping, yoga, Pilates, resistance bands, body-weight exercises and heavy gardening among examples of muscle-strengthening activity. The best approach is one you can perform safely, progressively and consistently.

What About Walking?

Walking is fantastic and deserves its own dedicated article. But walking and strength training are not interchangeable. Walking supports cardiovascular health, movement, mood and overall physical activity. Strength training specifically challenges your muscles against resistance. For healthy ageing, we want both. Move often. Walk regularly. Raise your heart rate. Challenge your muscles. Different forms of movement give your body different reasons to adapt.

Protein and Muscle

Training provides the stimulus. Nutrition provides the raw materials. Protein supplies amino acids needed for muscle protein synthesis and many other physiological functions. As we age, maintaining adequate protein intake becomes particularly relevant because older muscle can become less responsive to smaller amounts of dietary protein, a phenomenon sometimes described as anabolic resistance.

Protein can come from eggs, fish, meat and poultry, Greek yoghurt and other dairy foods, tofu and tempeh, beans and lentils, soy foods, nuts and seeds. The appropriate amount depends on age, body size, activity level, health and dietary pattern. We will explore this properly in a dedicated article on protein for women over 40.

And What About Creatine?

Creatine is a naturally occurring compound stored predominantly in skeletal muscle, where the phosphocreatine system helps rapidly regenerate ATP during periods of high energy demand. Creatine supplementation has a substantial research base in exercise and physical performance, and there is growing interest in its role across women's health and healthy ageing.

However, creatine does not replace resistance training. Think of training as the signal telling your body it needs this muscle. Nutrition and appropriate supplementation can support that process, but they cannot send the same signal as actually using your muscles.

Recovery Is Part of Building Strength

More is not always better. Muscle adapts to training during periods of recovery. That makes sleep, nutrition, rest and stress management part of the strength-building equation too. You do not have to train hard seven days a week to age well. You need an appropriate stimulus followed by enough recovery to adapt. Longevity is a long game. Your exercise routine should be sustainable enough to stay with you.

What If You Have Never Strength Trained Before?

Then today is still a perfectly reasonable time to begin. Ageing changes our physiology. It does not remove our ability to adapt. Older adults can still become stronger through appropriately designed resistance training. If you are new to exercise, have significant health conditions, experience pain or have concerns about balance, getting advice from a physiotherapist, appropriately qualified trainer or healthcare professional can help you begin safely. You do not need to start heavy. You need to start somewhere.

A Simple Muscle-Longevity Framework

What to prioritise	Why
Strength train at least twice weekly	Gives muscles a reason to maintain and build strength
Train major muscle groups	Supports whole-body physical function
Progress gradually	Muscles adapt when the challenge increases over time
Eat adequate protein	Provides amino acids required for muscle maintenance and repair
Stay active outside workouts	Supports overall physical and metabolic health
Include aerobic activity	Complements strength training and supports cardiovascular fitness
Prioritise sleep and recovery	Allows adaptation between training sessions
Practise balance as you age	Supports confidence, stability and fall prevention
Be consistent	Muscle is built and maintained over months and years

Myth vs Fact

Myth: Strength training is mainly about appearance.
Fact: Resistance training supports strength, physical function and healthy ageing. Systematic reviews have also associated muscle-strengthening activity with lower risks of several adverse health outcomes.

Myth: Women become bulky if they lift weights.
Fact: Significant muscle growth requires substantial training stimulus, adequate nutrition, genetics and time. Ordinary resistance training does not suddenly create a bodybuilding physique.

Myth: Walking is enough to maintain all your muscle.
Fact: Walking is excellent physical activity, but it does not provide the same progressive resistance stimulus as strength training.

Myth: Muscle loss is unavoidable after menopause.
Fact: Ageing and menopause can influence muscle, but resistance training, adequate nutrition and regular activity can help women maintain and improve strength.

Myth: It is too late to start after 60.
Fact: Older adults remain capable of adapting to resistance exercise. Starting appropriately later in life can still improve strength and physical function.

Myth: You need creatine to build muscle.
Fact: No. Resistance training and adequate nutrition are the foundations. Creatine may provide additional support in appropriate circumstances, but it is not compulsory.

Frequently Asked Questions

Why is muscle important for longevity?

Muscle supports movement, metabolism, balance and physical independence. Higher muscular strength and muscle-strengthening activity are also associated with better long-term health outcomes, although these observational associations do not prove that muscle alone extends lifespan.

At what age do women start losing muscle?

Changes in muscle mass and strength can begin gradually during adulthood and tend to become more significant with advancing age. The rate varies considerably between individuals and is influenced by activity, nutrition, health and hormonal factors.

Does menopause cause muscle loss?

The menopause transition may contribute to changes in muscle and body composition, but it is not the only factor. Age, physical activity, protein intake, sleep and overall health also matter.

How many times a week should women strength train?

Current UK guidance recommends muscle-strengthening activities involving the major muscle groups on at least two days each week.

Do I have to lift heavy weights?

Not necessarily. The resistance needs to challenge your muscles sufficiently for your current ability. As you become stronger, gradually increasing the challenge helps continued adaptation.

Is Pilates strength training?

Pilates can strengthen muscles, particularly depending on the movements and level of resistance involved. However, women aiming specifically to maximise strength may eventually benefit from additional progressive resistance.

Is yoga enough?

Yoga provides many benefits and certain styles can challenge muscle strength, balance and mobility. Whether it provides enough resistance for continued strength development depends on the individual and the practice.

Is strength more important than weight?

They tell us very different things. Body weight alone says remarkably little about physical capacity. Strength and functional ability can provide useful information about how well your body performs everyday tasks.

Can I start strength training in my 50s or 60s?

Yes. If you are new to exercise or have medical concerns, seek appropriate professional guidance and begin at a level suited to your current ability.

Key Takeaways

• Muscle is much more than something that moves your skeleton.
• It is metabolically active tissue and can release signalling molecules that communicate with other parts of the body.
• Muscular strength and muscle-strengthening activity are consistently associated with better health outcomes.
• For women, midlife is an important opportunity to prioritise strength rather than waiting until physical decline becomes obvious.
• Resistance training is one of the most effective ways to maintain and improve muscle strength.
• Protein, everyday movement, aerobic activity, sleep and recovery all support the bigger picture.
• Creatine may complement an appropriate programme for some women, but it does not replace training.
• Strength is not about becoming a bodybuilder. It is about maintaining your ability to live life on your terms.

The Nibu Longevity Take

For years, women were taught to measure progress by becoming smaller. A smaller dress size. A smaller number on the scales. A smaller waist. Healthy ageing invites us to measure something different. What can your body do?

Can you carry something heavy? Can you get up from the floor? Can you walk up the stairs without thinking about it? Can you travel, garden, dance, hike, play and live independently? Those abilities are easy to overlook until they become difficult. Muscle allows us to invest in them now.

You do not need to love the gym. You do not need visible abs. You do not need to lift the heaviest weight in the room. You simply need to give your body regular reasons to stay strong. Because the goal of healthy ageing is not to make a 50-year-old body look 25. It is to build a body at 50 that will support you at 60, 70, 80 and beyond. Do not train because you are afraid of getting older. Train for everything you still want to be able to do when you get there.

Conclusion

If mitochondria are part of the cellular machinery of healthy ageing, muscle is one of the most important tissues putting that energy to work. It moves us. Supports our metabolism. Communicates with other tissues. Helps protect our physical independence. And unlike many aspects of ageing that we cannot control, muscle remains responsive to something remarkably accessible: use.

Strength training will not stop ageing. Nothing will. But maintaining strength can help change what ageing looks and feels like. So perhaps one of the most useful questions we can ask ourselves is not how do I stay young, but what do I want my body to still be capable of in 20 years? Then start training for that life today.

References

1. Cruz-Jentoft AJ, et al. Sarcopenia: Revised European Consensus on Definition and Diagnosis (EWGSOP2). Age and Ageing. 2019.
2. Garcia-Hermoso A, et al. Muscular Strength as a Predictor of All-Cause Mortality in an Apparently Healthy Population: A Systematic Review and Meta-Analysis. Archives of Physical Medicine and Rehabilitation. 2018.
3. Shailendra P, et al. Resistance Training and Mortality Risk: A Systematic Review and Meta-Analysis. American Journal of Preventive Medicine. 2022.
4. Momma H, et al. Muscle-Strengthening Activities Are Associated With Lower Risk and Mortality in Major Non-Communicable Diseases. British Journal of Sports Medicine. 2022.
5. El-Kotob R, et al. Resistance Training and Health in Adults: An Overview of Systematic Reviews. Applied Physiology, Nutrition, and Metabolism. 2020.
6. Zhang Y, et al. Long-Term Resistance Training With All-Cause and Cause-Specific Mortality. British Journal of Sports Medicine. 2026.
7. Piccirillo R. Biological Aspects of Selected Myokines in Skeletal Muscle: Focus on Aging. International Journal of Molecular Sciences. 2021.
8. Strain T, et al. How Do Muscle and Bone Strengthening and Balance Activities Vary Across the Life Course. Journal of Frailty, Sarcopenia and Falls. 2019.
9. World Health Organization. WHO Guidelines on Physical Activity and Sedentary Behaviour. 2020.
10. NHS. Physical Activity Guidelines for Older Adults. Reviewed 2024.

Continue Reading

• Mitochondria and Ageing: Why Your Cellular Energy Matters More as You Get Older
• Creatine for Women Over 40: What Does the Science Actually Say? Coming next in The Nibu Journal.
• Creatine During Menopause: Benefits, Safety and How to Take It
• Why Creatine, Wild Salmon+ and Astaxanthin Make the Perfect Healthy Ageing Trio
• Protein for Women Over 40: How Much Do You Really Need? Coming soon.
• Inflammaging Explained: The Low-Grade Inflammation Linked With Ageing

About The Nibu Journal

The Nibu Journal is the educational home of Nibu Naturals, created to help women make informed decisions about healthy ageing. We explore longevity, women's health, nutrition, movement, skin health and supplements through clear, evidence-led education. We believe healthy ageing is not about fighting time. It is about building the strength, knowledge and habits that help you continue living well through every stage of life. Educate first. Support second. Sell naturally.

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Medical Disclaimer: This article is provided for educational purposes only and is not intended to diagnose, treat, cure or prevent any medical condition. If you have a medical condition, osteoporosis, significant joint problems, unexplained weakness, pain, concerns about falling or have been inactive for a long period, speak to your GP, physiotherapist or another appropriately qualified healthcare professional before beginning a new exercise programme. Food supplements should not be used as a substitute for a varied, balanced diet and healthy lifestyle.