Why Muscle Matters More as You Age: The Benefits of Maintaining Muscle After 40
“Muscle isn’t just about how you look. As you age, maintaining muscle helps preserve strength, physical capacity and your ability to keep doing the things you enjoy. Here’s why muscle matters — and how to build a stronger, more capable body after 40.”
If you think muscle is mainly about looking leaner, filling out a T-shirt or lifting heavier weights in the gym, you're missing the more important part of the equation.
Muscle is physical capacity.
It helps you climb stairs, carry shopping, get up from the floor, play with your children, walk further, run, hike, cycle, play sport and continue doing the things you enjoy as you get older.
And that is why maintaining muscle as you age becomes increasingly important.
You don't need to become a bodybuilder. You don't need to spend six days a week in the gym. You don't even need to particularly enjoy lifting weights.
Like I tell my clients as they jump on the assault bike: smiling is optional.
But if your goal is to build a body that is capable, resilient and prepared for the demands of life, maintaining muscle should be high on your list.
The scales can tell you how much you weigh.
They can't tell you what you're capable of doing.
Why Is Muscle Important?
Let's start with the obvious question: why is muscle important?
Muscle is responsible for producing force.
That sounds fairly simple, but force production underpins an enormous amount of what you do every day.
Every time you stand up from a chair, walk up a hill, lift a suitcase, pick something up from the floor or push open a heavy door, your muscles are doing work.
Your muscles also play an important role in:
Maintaining physical function
Supporting your joints
Producing force and power
Maintaining balance and coordination
Supporting your ability to perform everyday tasks
Helping you remain physically independent
Supporting glucose regulation and metabolic health
Providing a reserve of physical capacity when life gets difficult
That last point is particularly important.
Muscle is your physical reserve
Imagine that your current physical ability is a bank account.
Everyday life makes withdrawals.
You walk up stairs. You carry bags. You get up and down from the floor. You travel. You play sport. You garden. You look after your children. You occasionally have to move furniture because apparently that sofa definitely looked better on the other side of the room.
You need physical capacity to do all of it.
The more capacity you have, the further you are from your physical limit.
That doesn't mean you need to maximise everything.
You simply want enough capacity that normal life doesn't constantly feel like a maximum-effort event.
This is one of the reasons I view strength and fitness training differently from simply chasing a particular number on the scales.
The goal isn't just to make your body smaller.
The goal is to make your body more prepared.
Muscle Becomes More Important as You Age
As you get older, maintaining muscle becomes increasingly important because muscle mass and physical function can gradually decline.
This is a normal part of ageing.
But "normal" doesn't mean "there's nothing you can do about it."
Your body responds to what you repeatedly ask it to do.
If you consistently challenge your muscles, provide them with adequate nutrition and give yourself enough recovery, you give your body a reason to maintain its physical capacity.
If you stop providing that stimulus for years on end, your body has less reason to retain the same level of capacity.
This is why muscle mass and ageing are so closely connected.
The problem isn't simply losing muscle
When people hear about muscle loss with age, they often picture someone becoming visibly smaller.
That's not really the most useful way to think about it.
The bigger issue is what happens to your physical capability.
Imagine two people who weigh exactly the same.
One can comfortably:
Carry several heavy shopping bags
Get up from the floor without using their hands
Walk for two hours
Climb several flights of stairs
Pick up a suitcase
Play a recreational sport
The other struggles with several of these tasks.
The scales would tell you they're the same weight.
Their physical capacity tells a very different story.
So if you’re asking yourself why muscle matters: it’s ultimately a question about function rather than appearance.
Muscle Is About More Than Looking Muscular
There's nothing inherently wrong with wanting to change how you look.
If improving your body composition is one of your goals, strength training can absolutely form part of that process.
But I'd encourage you to think beyond aesthetics.
A stronger body gives you options.
It gives you the ability to say yes to things.
A long walk with friends.
A weekend hike.
A skiing holiday.
Playing football with your children.
Carrying your luggage through an airport.
Doing DIY without feeling completely destroyed afterwards.
Getting down on the floor and back up again.
These are not abstract fitness tests.
They're things that make up your life.
And I think that's a much more compelling reason to train than simply trying to look a certain way.
Big biceps are cool too, to be fair.
Your body should prepare you for the life you actually want
This is one of the principles that sits underneath my approach to strength and fitness training.
I don't want you to train simply because you have been told that you should.
I want your training to make your life better.
That means your programme should have some connection to the demands you actually place on your body.
If you enjoy hiking, your training should help you become better prepared for hiking.
If you play golf, you want a body capable of repeatedly producing force and moving well throughout a round.
If you have young children, being able to get up and down from the floor repeatedly might be more useful than being able to perform an impressive gym exercise.
Fitness becomes much more meaningful when it is connected to something you actually care about.
What Happens When You Lose Muscle With Age?
The phrase ‘loss of muscle with age’ can sound dramatic, but the underlying concept is straightforward.
As you age, it can become harder to maintain the same amount of muscle and physical capacity without deliberately training for it.
Several factors contribute to this:
1. You become less physically active
Modern life makes this remarkably easy.
You drive rather than walk.
You sit at a desk.
You work from home.
You use lifts instead of stairs.
You spend your evenings on the sofa because you've been working all day.
None of these things are inherently problematic.
The issue is the cumulative effect.
If your muscles aren't regularly exposed to challenging physical activity, you shouldn't expect them to maintain the same capacity indefinitely.
2. Your training history matters
Someone who has spent decades strength training has built a very different physical foundation from someone who has spent decades being relatively sedentary.
That doesn't mean the second person is doomed.
Far from it.
It simply means you have to start from where you are.
And this is where comparison becomes unhelpful.
You don't need to compare your current strength to somebody else's.
You need to compare it with your previous self.
If you couldn't comfortably squat down and stand back up six months ago but can now do it with confidence, that's progress.
If you can carry something today that felt heavy six months ago, that's progress.
If you can walk further, lift more, move better or recover more easily, that's progress.
Fitness isn't a competition against everyone else in the gym.
It's a conversation between who you were and who you're becoming.
3. Recovery and nutrition become increasingly important
Building and maintaining muscle isn't simply about lifting weights.
Your body needs an appropriate training stimulus, sufficient energy and adequate protein, alongside sleep and recovery.
This is one reason nutrition shouldn't be treated as completely separate from strength training.
If you're interested in the nutrition side, I've written more about how much protein you really need and why protein becomes particularly relevant when you're trying to maintain muscle.
But don't fall into the trap of thinking that you need a perfect diet.
You don't.
You need a diet that is good enough, consistently enough, to support the outcome you're trying to achieve.
Perfection is an impossible standard.
And an impossible standard is a remarkably effective way of making people feel like they're completely failing.
Can You Build Muscle After 40?
Yes.
Absolutely.
You can build muscle after 40.
The process doesn't suddenly stop because you've had a birthday.
Your body remains responsive to resistance training throughout adulthood.
However, you may need to become more thoughtful about how you train.
That might mean paying greater attention to:
Training consistency
Exercise selection
Appropriate training volume
Recovery
Sleep
Protein intake
Managing existing aches and injuries
Progressing gradually rather than constantly trying to destroy yourself
You also need patience.
This is where expectations can become a problem.
You aren't supposed to become highly skilled at something the first time you do it.
Strength training is a skill.
Building muscle is a biological adaptation.
Both require exposure and time.
You have to be willing to be the beginner.
The person who feels slightly awkward learning a new exercise.
The person who starts with lighter weights.
The person who doesn't know what half the equipment in the gym does.
That's fine.
In Carl Jung’s words: “You have to be willing to be the fool before you become the master.”
You Don't Need to Become "Muscular"
This is worth emphasising because the phrase ‘benefits of muscle mass’ can sometimes create the wrong mental image.
Maintaining muscle doesn't mean trying to become enormous.
For most adults, the goal is much simpler:
Have enough muscle and strength to support the life you want to live.
That's it.
You don't need to chase maximal muscle growth.
You don't need to train like a professional athlete.
You don't need to spend hours lifting weights.
And you certainly don't need to measure your success entirely through how your body looks. (This is a one-way road to misery.)
A useful training programme should improve your physical capabilities while fitting reasonably well into your actual life.
Because the best programme isn't the theoretically perfect programme.
It's the one you can actually sustain.
And that brings us to one of the most important distinctions when thinking about muscle as you get older...
Muscle isn't the same thing as strength.
You can have muscle without being particularly strong.
You can also become considerably stronger without dramatically increasing your muscle size.
Understanding that distinction helps explain why your training should focus on more than simply trying to increase muscle mass.
Muscle Isn't the Same as Strength
Although muscle and strength are closely related, they aren't identical.
Muscle provides the machinery for producing force.
Strength is your ability to use that machinery effectively.
Your nervous system, coordination, technique, experience and confidence all influence how strong you are.
That's why someone who has never strength trained can have perfectly healthy muscles but struggle to produce much force.
It's also why you can become noticeably stronger during the first few months of training without gaining a huge amount of muscle.
Your body is learning.
You're becoming more coordinated.
You're learning how to produce force.
You're becoming more comfortable with the exercises.
This is another reason not to judge your progress purely by appearance.
Strength is useful because life requires force
Consider some ordinary situations:
Getting yourself off the floor
Carrying your suitcase upstairs
Picking up a child
Moving a piece of furniture
Carrying shopping
Getting out of a low chair
Walking uphill
Climbing stairs
Catching yourself when you stumble
None of these require you to look particularly muscular.
They require you to be capable of producing force.
And that is where why strength training is important becomes much clearer.
Strength training isn't just about what happens inside the gym.
It's about increasing your ability to deal with what happens outside it.
Muscle, Strength and Physical Independence
One of the biggest reasons to care about maintaining muscle as you age is independence.
Being physically independent means being able to do things for yourself.
It means your physical limitations aren't unnecessarily dictating what you can and can't do.
That becomes increasingly valuable as you get older.
Imagine having the confidence to travel because you know you can manage your luggage.
Imagine going on a walking holiday without worrying whether your body will cope.
Imagine being able to play with your grandchildren rather than watching from the sidelines.
Imagine getting older without automatically assuming that physical decline means giving up the activities you enjoy.
This is the bigger picture.
Strength gives you a buffer
Think back to the bank-account analogy.
If an everyday task requires 50 units of physical capacity and you have 100, you've got plenty of room.
If you have 55, that same task is suddenly much closer to your limit.
The task hasn't changed.
Your reserve has.
This is why building physical capacity is so useful.
You aren't trying to make every activity maximally difficult.
You're trying to make normal life relatively easy.
A prepared body gives you a larger margin for error.
Why the Scales Don't Tell the Whole Story
Body weight can be useful information.
It can help you monitor trends when weight change is one of your goals.
But it is only one piece of information.
Your body weight doesn't tell you:
How strong you are
How much muscle you have
How fit you are
How well you move
How much you can lift
How easily you climb stairs
How far you can walk
How confident you feel physically
How capable you are in everyday life
You could weigh exactly the same as you did five years ago while being considerably stronger and fitter.
You could also weigh less while having lost some muscle and physical capacity.
The number on the scales can't distinguish between those scenarios by itself.
This is why I encourage people to broaden the definition of progress.
What should you measure instead?
If your goal is healthy ageing, I'd pay attention to several different forms of progress.
Strength
Are you gradually able to lift more weight or perform more repetitions with good technique?
Physical capacity
Can you walk further, climb more stairs or handle physically demanding activities more comfortably?
Movement
Are everyday movements becoming easier? Or are you continuing to find everyday movement easy?
Confidence
Do you feel more capable in your body?
Consistency
Are you training regularly rather than repeatedly starting and stopping?
Life
Can you do more of the things you actually enjoy?
These measures tell you considerably more about your physical development than a single number.
And there's something else worth remembering.
Your progress will not look identical to somebody else's.
You don't have their genetics, training history, schedule, injuries, responsibilities, sleep, stress levels or life circumstances.
Comparing yourself to them is therefore a fairly terrible measuring stick.
Compare yourself with the person you were yesterday.
How Strength Training Helps You Maintain Muscle as You Age
So, how do you actually preserve muscle as you age?
The answer is refreshingly simple.
Give your muscles a reason to stick around.
Resistance training provides that reason.
You don't need complicated exercises.
You need an appropriate stimulus, repeated consistently over time.
Focus on the basics
A well-designed strength programme should generally include movements that train the major functions of the body.
For example:
Squatting: sit-to-stand and squat variations
Hinging: deadlift and hip-hinge variations
Pushing: presses and push-up variations
Pulling: rows and pulldown variations
Single-leg work: split squats, step-ups and similar movements
Core training: exercises that challenge your ability to brace, and to move your core dynamically
You don't necessarily need all of these in every session.
The important thing is creating a balanced programme that suits your ability, goals and circumstances.
Progressive overload doesn't mean destroying yourself
Progressive overload simply means giving your body a sufficient enough stimulus to grow stronger.
That could mean:
Adding a little weight
Performing another repetition
Improving technique
Increasing range of motion
Doing another set
Making an exercise slightly more challenging
Becoming more consistent with your training
It doesn't mean turning every session into a battle for survival.
In fact, constantly exhausting yourself can make consistency harder.
The goal is to train hard enough to stimulate adaptation while still being able to get on with your life.
That's particularly important when you're balancing work, family and everything else that adulthood tends to throw at you.
How Often Should You Strength Train?
You don't need to live in the gym to benefit from strength training.
For most busy adults, two or three strength training sessions per week is an excellent starting point.
Even two well-structured sessions can provide a meaningful training stimulus.
The key is consistency.
Three sessions that you manage for three weeks followed by six weeks away from the gym aren't particularly useful.
Two sessions every week for the next few years?
That's a very different proposition.
This is why I generally prefer sustainable training over theoretically optimal training.
Your programme has to fit your life.
If it doesn't, the plan is wrong — not you.
Can You Lose Fat While Maintaining or Building Muscle?
Yes.
And this is another reason it is useful to stop thinking about health and fitness purely in terms of body weight.
If reducing body fat is one of your goals, strength training can help you maintain muscle while you lose weight.
That means the objective isn't necessarily:
"How quickly can I make the number on the scales go down?"
A better question can be:
"How can I improve my body composition while maintaining as much physical capacity as possible?"
Those are different goals.
And the second one is much more aligned with long-term health.
Don't turn fat loss into a punishment
This is where mindset matters.
You can approach your body from a place of frustration and self-criticism.
You can tell yourself that you aren't good enough, that you need to fix yourself, or that you have to become a completely different person.
That might create short-term motivation.
But I don't think it's a particularly good foundation for a healthy relationship with exercise.
You can want to change while still appreciating where you are now.
You can want to become stronger without believing that your current body is inadequate.
You can pursue improvement from a position of respect rather than punishment.
That's a much more sustainable place to operate from.
What If You Haven't Strength Trained for Years?
Start where you are.
Not where you think you should be.
Not where your friend is.
Not where you were at 25.
And definitely not where the person doing impressive things in the gym happens to be.
If you've spent years without strength training, your first few sessions might feel unfamiliar.
That's normal.
You're learning a new skill.
Your coordination needs to improve.
Your tissues need exposure to loading.
Your confidence needs to develop.
You may not feel particularly competent initially.
That's part of the process.
You don't learn to play the piano by being annoyed that you aren't Beethoven on lesson one.
Strength training works the same way.
Your first goal isn't perfection
Your first goal might simply be:
Turn up consistently.
Then perhaps:
Learn the basic movements.
Then:
Become more confident.
Then:
Start progressing the exercises.
Then:
Build enough strength and fitness that everyday life feels easier.
That's what progress looks like.
It isn't a perfectly linear graph.
Some weeks you'll train three times.
Some weeks life will get in the way.
You might get ill.
You might go on holiday.
Work might become chaotic.
That's life.
The answer isn't to abandon the entire process because you missed a session.
Get back to it.
Progress is better than perfection because perfection doesn't exist.
A Simple Framework for Maintaining Muscle After 40
If you're looking for a practical starting point, I'd keep things surprisingly simple.
1. Strength train consistently
Aim for two to three sessions per week.
Prioritise the major movement patterns and progressively challenge yourself.
2. Stay physically active outside the gym
Strength training isn't a replacement for movement.
Walk.
Cycle.
Garden.
Play sport.
Take the stairs.
Go hiking.
Do the things you enjoy.
Your body was designed to be used.
3. Eat enough protein
Include a meaningful source of protein in your meals and make your overall diet varied and nutritious.
You don't need to make every meal "perfect."
4. Prioritise recovery
Sleep matters.
So does managing your overall workload.
Training is a stressor. Recovery is where your body adapts to it.
5. Make your training relevant
Think about the activities you want to be able to do in five, ten or twenty years.
Then train for those capabilities.
Your programme should prepare you for your life, not become another burden you have to squeeze into it.
6. Track useful progress
Don't rely exclusively on your body weight.
Track strength, consistency, physical capacity and the things that matter to you.
The objective is not simply to become a person who exercises.
It's to become a person who is physically prepared for life.
What Happens If You Stop Strength Training?
This is an important consideration.
The adaptations you build through training aren't permanent.
If you stop challenging your body for a prolonged period, you can gradually lose some of the strength, muscle and fitness you've developed.
That doesn't mean missing a week matters.
It doesn't.
You don't lose everything because you went on holiday.
You don't need to panic because you missed a couple of workouts.
Again, we're back to the same principle:
Consistency over the long term matters far more than perfection in the short term.
Think in years rather than individual workouts.
That's a much healthier way to approach training.
The Bigger Picture: You're Building Physical Capacity
This is ultimately why I think ‘why muscle is important’ is the wrong question to ask if we're only thinking about appearance.
A better question is:
What do I want my body to be capable of doing?
Because muscle is part of the answer.
Strength is part of the answer.
Fitness is part of the answer.
Mobility, coordination, balance, confidence and skill are part of the answer too.
The objective isn't to maximise every physical quality.
It's to build enough capacity that your body supports your life rather than limiting it.
That's what I mean when I talk about building a more prepared body.
You aren't training for the gym.
You're training for everything outside it.
Final Thoughts
Maintaining muscle as you age isn't about chasing an impressive physique.
It's about maintaining your ability to live the life you want.
Muscle helps you produce force.
Strength allows you to use that force.
Fitness allows you to sustain activity.
And together, these qualities contribute to a body that is better prepared for the demands of everyday life.
You don't need to become a fitness fanatic.
You don't need a perfect diet.
You don't need to train every day.
You don't need to compare yourself with someone half your age who appears to spend approximately 14 hours a day in the gym.
You simply need to start building capacity and then keep building it.
Start where you are.
Be patient.
Accept that you're going to be imperfect.
Then look back six months from now and ask a much more useful question than "What do I weigh?"
Ask:
"What can I do now that I couldn't do before?"
That's progress.
And that's a much better measure of what your training is actually giving you.
Want Help Building a Stronger, More Capable Body?
You don't need another generic workout programme.
You need a training approach that takes into account your goals, your current ability, your lifestyle and the things you actually want your body to be capable of doing.
If you're based in Oxford and you'd like help building strength, improving your fitness and developing sustainable habits around your existing life, you can start by completing my coaching pre-application form.
I'll use your answers to understand where you're starting from, what you're trying to achieve and whether my coaching is the right fit for you.
Complete the Coaching Pre-Application Form
Frequently Asked Questions
1. Is it too late to build muscle after 40?
No. You can still build muscle and strength well beyond 40. Your rate of adaptation may differ from when you were younger, but your body remains responsive to appropriate resistance training throughout adulthood.
2. How can I maintain muscle as I age?
The fundamentals are straightforward: strength train consistently, remain physically active, consume adequate protein and energy, and prioritise recovery. You don't need a complicated programme, but you do need a consistent stimulus.
3. How many days a week should I strength train after 40?
For most busy adults, two to three well-structured strength sessions per week is a very practical starting point. More isn't automatically better if additional training makes it difficult to recover or maintain consistency.
4. Does walking help maintain muscle?
Walking is excellent for general physical activity and cardiovascular health, but it provides a different stimulus from progressive resistance training. If maintaining muscle and strength is a priority, strength training should have a place alongside regular walking and other activity.
5. Do I need to lift heavy weights to build muscle?
No. Muscle can respond to a range of resistance-training loads when the training provides a sufficient stimulus. Heavier training can be useful, but you don't need to lift extremely heavy weights to make progress.
6. Is muscle more important than body weight?
They measure different things, so it's not really an either/or question. Body weight can be useful information, but it doesn't tell you how strong, fit or physically capable you are. If your goal is healthy ageing, physical capacity deserves considerably more attention than the scales alone.
7. Can I build muscle while losing body fat?
It is possible, particularly in people who are new to resistance training, returning after a break, or carrying more body fat. However, the exact outcome depends on factors such as training status, nutrition, recovery and individual physiology.
8. What is the best exercise for maintaining muscle as you age?
There isn't one magic exercise. A good programme should train the major movement patterns and progressively challenge the muscles while accounting for your goals, experience and circumstances. The best programme is one you can perform consistently and progress over time.
About the Author
I'm Jamie, founder of JJ Strength & Fitness in Oxford. I help busy adults become stronger, fitter and more resilient through practical, evidence-based coaching designed around real life. My approach is focused on building a body that's prepared for the demands of everyday life and the activities you enjoy, rather than chasing perfection or short-term results.
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