You reach your forties or fifties and start noticing a few changes.
Perhaps your waistline is expanding, even though you don't think you're eating any differently. Maybe you're finding it harder to maintain the muscle you once had, or you simply don't have the same energy you used to.
The workouts that worked in your twenties and thirties don't seem to deliver quite the same results anymore.
So what's going on?
Spend five minutes scrolling through social media and you'll probably come across someone telling you that low testosterone is the reason you're gaining belly fat, losing muscle and feeling tired.
And, of course, they'll often have a supplement, training programme or miracle solution to sell you.
But is testosterone really responsible for all these changes?
The answer isn't quite that simple.
While testosterone levels can decline as men get older, there's much more to maintaining strength, fitness and a healthy body composition after 40 than simply focusing on hormones.
Let's look at what's actually happening and, more importantly, what you can do about it.
What Happens to Testosterone Levels as Men Age?
Testosterone is an important hormone involved in several aspects of men's health, including muscle development, bone health, sexual function and the production of red blood cells.
Levels generally reach their highest point during early adulthood before gradually declining with age.
According to the NHS, testosterone levels may decrease by approximately 1% per year from around the age of 30 to 40.
However, that doesn't mean every man over 40 has low testosterone or that a gradual decline automatically causes health problems.
In fact, many men maintain testosterone levels within the normal range well into later life.
And while genuine testosterone deficiency is a recognised medical condition, it shouldn't be confused with the normal ageing process.
What Are the Signs of Low Testosterone?
Low testosterone, sometimes referred to as testosterone deficiency or hypogonadism, can cause a range of symptoms.
These may include:
Reduced sex drive.
Erectile difficulties.
Loss of muscle mass and strength.
Increased body fat.
Reduced energy or persistent fatigue.
Changes in mood.
Reduced bone density.
But here's the important part.
Experiencing one or more of these symptoms doesn't automatically mean your testosterone is low.
Fatigue, weight gain and reduced motivation are relatively common, particularly during midlife, and can have several different causes.
Poor sleep, stress, reduced physical activity, changes in diet, certain medications and underlying health conditions can all contribute.
If you're concerned about persistent symptoms, the sensible starting point is a conversation with your GP.
Testosterone deficiency is diagnosed through a combination of symptoms and appropriately timed blood tests, rather than symptoms alone.
Is the Male Menopause a Real Thing?
You might have heard the term male menopause, sometimes called andropause.
It's become a popular way of describing the physical and emotional changes some men experience during middle age.
However, the NHS explains that the term is misleading.
Unlike the female menopause, where hormone levels change significantly over a relatively defined period, testosterone in men generally declines gradually.
There isn't an equivalent universal hormonal transition that every man experiences.
That's not to dismiss the changes men can experience as they get older.
It's simply important to understand that not every change in energy, mood or body composition is caused by testosterone.
And that's good news, because many of the factors influencing how you feel and perform are things you can work on.
Why Does Building and Maintaining Muscle Become More Difficult After 40?
One of the most noticeable changes for many men is that maintaining muscle seems to require more effort than it used to.
You might find that you're not as strong as you once were, or that you've gradually lost some muscle definition.
Part of this is related to ageing.
As we get older, we become more susceptible to losing muscle mass and strength, particularly if we're not regularly challenging our muscles.
This age-related loss of muscle is often referred to as sarcopenia.
However, it's not something that suddenly starts on your 40th birthday, and it isn't inevitable that you'll become weak as you age.
Lifestyle plays a significant role.
If you've moved from an active job to sitting at a desk, stopped playing sport or gradually reduced how much exercise you do, your muscles may simply be getting less stimulation than they used to.
The encouraging news?
You can still build muscle and improve your strength in your forties, fifties, sixties and beyond.
And one of the most effective ways to do that is through regular resistance training.
Why Strength Training Matters for Men Over 40
Strength training is sometimes associated with bodybuilding or trying to develop bigger muscles.
But its benefits go far beyond appearance.
For men over 40, maintaining strength can make an enormous difference to physical health, everyday function and quality of life.
1. Helps Maintain and Build Muscle
Muscles respond to being challenged.
Whether you're using dumbbells, resistance bands, gym equipment or your own bodyweight, resistance training provides the stimulus your muscles need to become stronger.
With an appropriately structured programme, you can maintain and often increase muscle mass as you age.
And you don't need to train like a bodybuilder to see benefits.
Two or three well-planned strength sessions each week can be an excellent starting point.
2. Supports Healthy Body Composition
It's common for men to notice increased fat around their abdomen as they get older.
But while hormones can play a role, changes in activity levels, food intake, sleep and muscle mass can all contribute.
Strength training helps preserve muscle, particularly when combined with appropriate nutrition and regular physical activity.
This matters because losing weight isn't always the same as improving your body composition.
If you lose weight but also lose a significant amount of muscle, you may not achieve the improvements in strength, fitness and appearance you're looking for.
A better approach is often to focus on reducing excess body fat while maintaining or building muscle.
3. Improves Everyday Strength and Function
Think about the physical activities you want to continue doing as you get older.
Playing sport, working in the garden, carrying heavy shopping, travelling, keeping up with your children or grandchildren, or simply getting through the day without feeling physically exhausted.
Strength training helps maintain the muscular strength needed for these activities.
And that's something worth investing in.
4. Supports Long-Term Health
Regular resistance training is associated with improvements in several important areas of health, including physical function, bone health and metabolic health.
Combined with cardiovascular exercise, it forms an important part of maintaining fitness as you age.
The aim isn't simply to look better at 45 or 50.
It's to remain strong, active and capable at 60, 70 and beyond.
Can Exercise Naturally Increase Testosterone?
This is one of the most common questions surrounding men's fitness.
And it's also where some of the biggest misconceptions appear.
Resistance training can produce a temporary increase in testosterone levels immediately after exercise.
However, that doesn't mean lifting weights will permanently raise your testosterone or reverse a medically diagnosed deficiency.
In men with normal testosterone levels, the evidence that exercise alone produces large, sustained increases in resting testosterone is limited.
That doesn't make exercise any less valuable.
You don't need to increase your testosterone to benefit from strength training.
You can improve your muscle strength, fitness, body composition and overall health without producing a significant change in your resting testosterone levels.
If you have genuine testosterone deficiency, exercise can still form part of a healthy lifestyle, but it isn't a substitute for appropriate medical assessment or treatment.
Five Things Men Over 40 Can Do to Improve Their Strength, Fitness and Energy
Rather than chasing testosterone-boosting shortcuts, I'd focus on five practical areas that can make a genuine difference.
1. Make Strength Training a Priority
If you're not currently doing any resistance training, this is one of the best places to start.
Aim to train your major muscle groups at least twice a week.
A simple full-body programme might include:
Squats or sit-to-stands.
Lunges or step-ups.
Press-ups or chest presses.
Dumbbell or resistance-band rows.
Hip bridges or hip hinges.
Core strengthening exercises.
You don't need complicated workouts or expensive equipment.
What matters is using exercises appropriate to your ability and gradually increasing the challenge as you get stronger.
2. Don't Neglect Cardiovascular Fitness
Strength is important, but so is your heart and lung fitness.
Walking, cycling, swimming, jogging and other aerobic activities can help improve cardiovascular health, stamina and overall wellbeing.
UK physical activity guidelines recommend at least 150 minutes of moderate-intensity exercise each week, or 75 minutes of vigorous activity, alongside muscle-strengthening exercise.
If you're currently inactive, build up gradually.
You don't need to go from doing very little to training every day.
3. Pay Attention to Your Nutrition
You can't out-train a consistently poor diet.
If your goal is to lose excess body fat, your overall energy intake matters.
If you're trying to maintain or build muscle, getting enough protein and eating a balanced diet are important.
Rather than looking for a testosterone-boosting superfood, focus on the basics.
Include a variety of protein sources, fruit, vegetables, wholegrains and healthy fats.
Avoid extreme diets that are difficult to maintain.
And remember that sustainable changes are usually more valuable than short-term results.
4. Take Sleep and Recovery Seriously
Sleep often becomes an afterthought when life gets busy.
But poor sleep can affect your energy, concentration, appetite, training performance and recovery.
Some sleep problems can also affect hormone levels.
Aim for a consistent sleep routine and enough rest to support your daily activities and exercise.
If you're regularly exhausted despite getting what seems like enough sleep, particularly if you snore heavily or wake up gasping, speak to your GP.
5. Be Consistent Rather Than Extreme
You don't need six gym sessions a week, endless cardio or a punishing diet to improve your fitness after 40.
In fact, trying to do too much too quickly is often a recipe for frustration.
Start with something manageable.
Two strength sessions, regular walking and some simple nutrition improvements can be a very effective foundation.
Once those habits are established, you can build on them.
Consistency over months and years will usually deliver far more than an occasional burst of extreme effort.
What Could a Weekly Fitness Routine Look Like for a Man Over 40?
If you're unsure where to start, here's an example of how you could structure your week.
Day - Activity
Monday - Full-body strength workout
Tuesday - Brisk walk or cycling
Wednesday - Rest or gentle mobility
Thursday - Full-body strength workout
Friday - Brisk walk or other cardio
Saturday - Longer walk, sport or an activity you enjoy
Sunday - Rest or gentle movement
This isn't a one-size-fits-all plan.
Your programme should reflect your current fitness, experience, goals and any health considerations.
The important thing is to find a routine you can maintain and gradually progress.
Frequently Asked Questions About Testosterone and Fitness After 40
Does testosterone automatically drop after 40?
Testosterone levels generally decline gradually with age, but the rate varies between individuals. A lower level doesn't automatically mean you have a medical deficiency or require treatment.
Does low testosterone cause belly fat?
Testosterone deficiency can influence body composition, but increased abdominal fat has several possible causes. Carrying excess body fat can also be associated with lower testosterone levels. Belly fat alone isn't evidence of a hormone problem.
Can lifting weights boost testosterone after 40?
Resistance training may temporarily increase testosterone after a workout, but it doesn't reliably produce large, lasting increases in resting testosterone. Its main benefits include improved strength, muscle mass and physical function.
Is it possible to build muscle after 50?
Absolutely. Men can improve muscle strength and often build muscle well beyond 50, particularly with progressive resistance training, appropriate nutrition and adequate recovery.
Should I take testosterone boosters?
Be cautious of supplements claiming to dramatically increase testosterone. Many lack convincing evidence of meaningful benefits. If you suspect testosterone deficiency, speak to your GP rather than relying on supplements or self-prescribed hormones.
When should I get my testosterone checked?
If you have persistent symptoms such as reduced libido, erectile difficulties or unexplained loss of muscle and strength, discuss them with your GP. They can assess possible causes and arrange appropriate blood tests if indicated.
Getting Older Doesn't Mean Getting Weaker
It's easy to assume that gaining weight, losing muscle and feeling less energetic are simply unavoidable parts of getting older.
But while our bodies do change with age, that doesn't mean we have to accept becoming less fit or less capable.
And it certainly doesn't mean every problem can be blamed on testosterone.
For many men, the most useful place to start isn't with a supplement or hormone test.
It's with the fundamentals: regular strength training, cardiovascular exercise, balanced nutrition, adequate recovery and a routine that fits into everyday life.
You might not be able to turn back the clock.
But you can become stronger, fitter and healthier than you are today.
And that's a goal worth working towards at any age.
Build Your Strength and Fitness with Epic Fitness Online Coaching
At Epic Fitness, we believe getting older shouldn't mean giving up on feeling strong, fit and confident.
Our online fitness coaching is designed to help you develop sustainable exercise habits, improve your strength and work towards your goals without extreme workouts or unrealistic expectations.
Whether you're returning to exercise after a few years away or looking to make better progress with your existing training, we can help you find an approach that works for you.
With structured workouts, personalised guidance and ongoing support, you can build a routine that fits around your life.
Ready to get stronger after 40? Get in touch with Epic Fitness to find out more about our online coaching.
This article provides general fitness information and is not a substitute for medical advice. If you're experiencing persistent fatigue, sexual symptoms or other unexplained changes in your health, speak to your GP. Testosterone deficiency requires medical assessment and cannot be diagnosed from symptoms alone.
Sources and Further Reading
NHS. The 'Male Menopause' - explains testosterone changes with age, symptoms and possible alternative causes.
Endocrine Society (2026). Statement on Testosterone Replacement Therapy - guidance on diagnosis and appropriate testing.
Endocrine Society. Testosterone Therapy for Hypogonadism: Clinical Practice Guideline - clinical recommendations for diagnosing and managing testosterone deficiency.
NHS. Physical Activity Guidelines for Adults Aged 19–64 - recommendations for resistance training and cardiovascular exercise.
NHS. How to Improve Your Strength and Flexibility - practical guidance for developing muscular strength.