Five reps. Eight reps. Ten reps. Fifteen reps.
Look at enough strength-training programmes and you’ll find all of them. One exercise might call for 5–8 repetitions, another 8–12 and another 12–15.
Then you’ll come across someone claiming that low reps are for strength, 8–12 are for muscle and anything above 15 is muscular endurance.
Add age into the equation and things become even more confusing.
Men over 40 are often told they should stop lifting heavy and switch to lighter weights and higher repetitions. The implication is that lower-rep training belongs to younger lifters, while getting older requires a fundamentally different approach.
So, how many reps should men over 40 do?
There isn’t one number that applies to everyone.
Your training goal, the exercise you’re performing, the resistance you’re using, how hard the set is and your training experience are all more useful guides than your age alone.
If maximising strength is your main objective, relatively heavier training has a clearer advantage. If building muscle is the goal, research suggests that muscle growth can occur across a much broader range of repetitions.
And if, like many Over Lifestyle readers, you want to be both stronger and more muscular?
You probably don’t need to choose one rep range at all.
Rep ranges are programming tools, not age rules.
Here’s how to use them.
What Does a Rep Range Actually Tell You?
A rep range simply tells you how many repetitions you’re aiming to perform in a set.
A programme might prescribe:
6–8 reps
or:
8–12 reps
or:
12–15 reps.
But the number alone doesn’t tell you how demanding the set actually is.
Imagine performing ten dumbbell presses with a weight you could lift 25 times if you really tried. Now compare that with performing ten repetitions using a weight you could lift perhaps 11 or 12 times.
Both sets contain ten repetitions. They’re clearly not the same training stimulus. That’s why repetitions need to be considered alongside load and effort.
Generally, heavier resistance limits how many repetitions you can perform. Lighter resistance allows more.
But how close you get to the point where you can no longer complete another good repetition also influences how challenging the set is.
This is one reason simple statements such as:
“Do 8–12 reps to build muscle.”
only tell part of the story.
Eight to twelve can be a very useful rep range. It just isn’t the only one that can build muscle.
Is 8–12 Really the Best Rep Range for Building Muscle?
The traditional bodybuilding advice is familiar:
1–5 reps for strength.
8–12 reps for muscle.
15+ reps for muscular endurance.
There’s some useful logic hidden inside that model, but the boundaries are much less rigid than they appear.
A 2021 systematic review and network meta-analysis examining resistance-training load, muscle growth and strength compared training using low loads of more than 15-repetition maximum, moderate loads of 9–15RM and high loads of 8RM or heavier.
The researchers found no significant differences in muscle hypertrophy between the different loading categories.
That doesn’t mean every rep range is interchangeable in every workout.
The studies involved sets taken until participants could no longer complete another repetition, which is worth noting. This doesn’t mean factors such as exercise choice, fatigue and personal preference don’t matter.
What it does tell us is that muscle growth isn’t confined to a narrow 8–12-rep zone.
But don’t make the opposite mistake and conclude that 8–12 is therefore useless.
For many exercises, moderate rep ranges provide an extremely practical way to train. You can use meaningful resistance while accumulating a reasonable number of repetitions, and progression is relatively straightforward to track.
So instead of:
8–12 is the muscle-building range.
A better interpretation is:
8–12 is one useful muscle-building range among several.
If your primary objective is adding muscle, our guide to How to Build Muscle After 40 covers the wider training, nutrition and recovery principles involved.
How Many Reps Are Best for Strength?
If your goal is to maximise the amount of weight you can lift, relatively heavy training becomes increasingly important.
The American College of Sports Medicine’s 2026 Position Stand on resistance training synthesised evidence from 137 systematic reviews involving more than 30,000 participants. Resistance training improved muscular strength and hypertrophy across a variety of training prescriptions, but heavier loads of at least 80% of one-repetition maximum (1RM) were associated with greater improvements in strength.
A large 2023 systematic review and Bayesian network meta-analysis reached a similar conclusion. All of the resistance-training prescriptions examined improved strength compared with no exercise, but higher-load training ranked most highly for strength development.
One important part of the explanation is training specificity.
If you want to become particularly good at lifting heavy resistance, you need some exposure to lifting relatively heavy resistance.
But that doesn’t mean:
Strength = 1–5 reps and nothing else works.
There’s a difference between maximising your one-repetition maximum and simply becoming stronger.
Someone relatively new to resistance training can become substantially stronger while performing sets of six, eight, ten or more repetitions. Muscle growth itself can also contribute to longer-term strength potential.
So if your goal is general strength and muscle rather than competitive powerlifting or maximising a particular 1RM, there’s no requirement to perform every major exercise for sets of three or five.
Lower-repetition training is a tool. It’s not a requirement for becoming strong.
Can Higher Reps Still Build Muscle After 40?
Yes.
The broader load literature shows that hypertrophy can occur with relatively light resistance and higher repetitions, particularly when sets are performed with substantial effort.
But there’s an important phrase in that sentence:
substantial effort.
Twenty repetitions with a resistance you could comfortably lift 40 times shouldn’t be treated as equivalent to a genuinely demanding set simply because you’ve reached a particular number.
Research also suggests that effort matters for hypertrophy.
A 2024 meta-regression examining proximity to failure, strength and muscle hypertrophy found that muscle growth tended to increase as sets were terminated closer to failure, although the researchers emphasised uncertainty around the precise relationship.
That doesn’t establish an exact number of repetitions you must leave in reserve. And it doesn’t mean every lighter-weight set must be taken to absolute muscular failure.
It does reinforce a useful principle:
Using lighter weights doesn’t remove the need to challenge the muscle.
Higher-repetition training also comes with practical considerations.
Perform a demanding set of 15 or 20 repetitions and you may experience substantial local discomfort. On large compound movements, breathing and general fatigue can become increasingly noticeable too.
For some exercises that’s manageable. For others, a somewhat heavier resistance and fewer repetitions may simply be a more practical way to train.
The conclusion isn’t that everyone should train with lighter weights and higher reps.
It’s that meaningful muscle growth can occur across a broad range of repetitions when the training provides an adequate stimulus.
Does Being Over 40 Change the Rep Range You Should Use?
This is where individual circumstances need to be separated from arbitrary age rules.
There is no established physiological switch at your 40th birthday that suddenly assigns you a new repetition range.
In the 2023 network meta-analysis mentioned earlier, researchers investigated potential moderators including age, training status and sex distribution. Age did not show an obvious modifying effect on the relative effects of the different resistance-training prescriptions, although sparse data reduced the precision of some estimates.
That doesn’t prove age can never influence how training should be organised.
Research specifically involving older adults also doesn’t support the blanket idea that ageing means abandoning heavier resistance.
A meta-analysis comparing moderate- and heavy-load resistance training in older adults examined 15 studies involving 448 participants with a mean age of approximately 68. Both approaches produced substantial improvements, while heavier-load training tended to produce slightly greater strength gains.
Those participants were considerably older than many Over Lifestyle readers, so this isn’t evidence establishing the ideal training method for every man in his 40s or 50s. But it certainly doesn’t support a simple rule that getting older means you must switch to light weights and high repetitions.
What can matter is your individual context.
A man who has trained consistently for 25 years enters his 50s with a very different training history from someone starting resistance training for the first time at 45.
Exercise choice matters. Current capability matters. Training experience matters. Your goals matter.
Your health, injury history and ability to recover from your overall training programme may matter too.
Programme the goal and the individual context—not the birthday.
If you’re new to strength training, returning after a long break or making a substantial change to the way you train, guidance from an appropriately qualified fitness professional can also be valuable. They can help you choose exercises, loads and progressions that suit your current ability rather than simply applying a generic programme.
A Practical Rep-Range Framework for Men Over 40
If the science doesn’t give us one perfect rep range, how should you actually think about repetitions in your training?
A useful approach is to consider the purpose of the exercise and what you’re trying to achieve.
The table below is an Over Lifestyle programming framework designed to illustrate how different ranges might be used. The exact numerical boundaries aren’t ranges established as optimal by the research above.
| Practical use | Example rep range | Why you might use it |
|---|---|---|
| Heavier strength-focused work | 3–6 | A practical range for using relatively heavy resistance when strength is being emphasised |
| Strength and muscle overlap | 6–10 | A useful middle ground for many compound exercises |
| Moderate-rep muscle-focused work | 8–15 | Practical for accumulating challenging hypertrophy-oriented work |
| Higher-rep accessory work | 12–20+ | Can provide useful muscle-building work with lighter resistance |
There is deliberate overlap in that table.
These are practical programming examples, not scientifically defined zones or age-specific prescriptions.
It’s also important to recognise that changing the repetition range usually changes the resistance being handled.
Lower-repetition strength work generally involves greater absolute loads than moderate- or higher-repetition training. As the resistance increases, good exercise selection, sound technique and sensible progression become increasingly important.
Lighter resistance reduces the amount of external load being handled on each repetition and may feel more comfortable or practical for some people, exercises or circumstances. But that doesn’t make higher-repetition training automatically safer—or heavier resistance inherently unsafe.
A demanding set with a lighter weight can still place substantial demands on the muscles and the rest of the body.
Likewise, the inclusion of 3–6 reps in this framework shouldn’t be interpreted as an instruction for a beginner to start lifting near-maximal weights.
If you’re new to resistance training, moderate rep ranges can still build substantial strength while giving you time to develop technique, confidence and training experience. Heavier, lower-repetition work can then be introduced where appropriate rather than treated as something you must perform simply because strength is one of your goals.
Six repetitions don’t suddenly stop contributing to strength when you perform a seventh. Likewise, your muscles don’t stop receiving a hypertrophy stimulus when you move beyond 12.
Think of rep ranges as different tools with overlapping uses rather than separate lanes that you’re forbidden to cross.
A programme designed for both muscle and strength might therefore include some relatively heavy sets on major exercises, moderate-repetition work across much of the programme and higher-repetition work on selected accessory movements.
You don’t have to pick one range and use it for everything.
Why Different Exercises Can Suit Different Rep Ranges
Once you stop searching for one universally optimal rep range, another question becomes easier to answer:
Why do well-designed programmes prescribe different repetitions for different exercises?
Consider a dumbbell lateral raise and a Romanian deadlift.
You could perform both for the same number of repetitions.
But there’s no particular reason you have to.
A lateral raise uses relatively little external resistance and is commonly performed as an accessory movement. Using a moderate-to-higher rep range can be a practical way to train it.
A Romanian deadlift allows substantially heavier resistance and involves much more muscle mass. Many people may find moderate repetitions more practical than very long, demanding sets.
Likewise, a bench press or squat variation can be programmed for relatively low repetitions when strength is being emphasised, while curls and triceps extensions don’t need to follow exactly the same prescription.
This isn’t because research has established one mandatory repetition range for every exercise.
It hasn’t. It’s a programming decision.
A set of five lateral raises isn’t automatically superior because you’ve managed to use a heavier dumbbell.
And a 20-rep Romanian deadlift isn’t automatically superior for muscle growth because higher-repetition training can stimulate hypertrophy.
The rep range needs to make sense in the context of the exercise and your objective.
You’ll see this principle applied in our Best Dumbbell Workout for Men Over 40, where larger compound exercises and smaller accessory movements deliberately use different repetition ranges.
How Hard Should Your Sets Be?
Rep ranges tell you what you’re aiming for.
They don’t completely tell you how hard to train.
Suppose your programme calls for 8–12 repetitions.
If you perform 12 repetitions but could easily have completed another ten, simply reaching the top of the range doesn’t necessarily mean you’ve produced the training stimulus you intended.
For muscle-building work, the set generally needs to become sufficiently challenging for the target muscle. Research suggests that hypertrophy tends to increase as sets are terminated closer to failure, but the exact relationship remains uncertain.
That doesn’t mean every working set needs to end in absolute muscular failure.
How close you need to train to failure—and whether you ever need to reach it—is a separate programming question.
The important point here is simpler:
Rep count and effort need to be considered together.
Ten hard repetitions and ten easy repetitions aren’t the same thing.
How Do Rep Ranges Fit With Progressive Overload?
Choosing a rep range is only the beginning.
You also need a way to progress within it.
Imagine you’re performing dumbbell bench presses for 8–12 repetitions.
You might start with:
20 kg × 8
Over subsequent workouts, that might become:
20 kg × 9
then:
20 kg × 10
and eventually:
20 kg × 12
Once you can perform the top end of your target range with good technique and the intended level of effort, increasing the resistance and returning towards the lower end gives you another way to continue progressing.
This is known as double progression.
Our guide to Progressive Overload After 40 explains this process in more detail, along with other ways of progressing when simply adding weight isn’t appropriate.
The important distinction is:
Your rep range defines the framework. Progressive overload moves you through it.
Common Rep-Range Mistakes Men Over 40 Make
1. Always Stopping at 10 Because the Programme Says 10
A programme says:
3 × 10.
So you perform ten repetitions and stop.
But what if you could comfortably have performed 15?
Following the written number doesn’t automatically make the set effective.
Rep targets need to be interpreted alongside the intended resistance and effort.
2. Assuming Higher Reps Are Automatically Safer After 40
There isn’t a universal repetition threshold at which resistance training suddenly becomes “safe”.
Using lighter resistance doesn’t automatically guarantee good technique, appropriate exercise selection or sensible fatigue management.
Likewise, relatively heavy resistance isn’t automatically inappropriate simply because you’re over 40.
What does change as resistance gets heavier is the amount of external load you have to control. That’s another reason technique, appropriate exercise selection and gradual progression matter.
Training needs to reflect the individual, exercise and circumstances rather than an arbitrary age-based rule.
3. Turning Every Exercise Into Heavy Low-Rep Work
Recognising that heavier training has advantages for maximal strength doesn’t mean every exercise should be performed for three or five repetitions.
If you’re training for a combination of strength and muscle, there can be good practical reasons to use different rep ranges across your programme.
Your lateral raise doesn’t need to become a test of maximal strength just because heavy resistance is useful elsewhere in your programme.
4. Thinking More Reps Automatically Means More Muscle
If ten reps can build muscle, surely 20 must build twice as much?
It doesn’t work that way.
The resistance, effort, number of sets, exercise and wider programme all matter.
More reps aren’t automatically better reps.
Frequently Asked Questions About Reps After 40
Is 8–12 Reps Good for Men Over 40?
Yes.
Eight to twelve repetitions is a practical range for many resistance-training exercises and can form part of training for both muscle and strength.
What the research doesn’t support is treating 8–12 as the only effective muscle-building range or as a special prescription for people over 40.
Should Men Over 40 Avoid Low Reps?
There isn’t good evidence for a blanket rule that men should avoid lower-repetition training simply because they’ve turned 40.
Relatively heavier resistance can have an important role when maximal strength is a priority.
Whether lower-repetition work makes sense for a particular exercise or programme depends on factors including your training experience, current capability and goals.
Are 15–20 Reps Too High for Building Muscle?
No.
Muscle growth can occur with relatively lighter resistance and higher repetitions when the training provides sufficient challenge.
That doesn’t mean every exercise needs to be performed for 15–20 reps. Higher-repetition sets can be demanding and may be more practical for some exercises than others.
Should I Use the Same Rep Range for Every Exercise?
Not necessarily.
Different exercises can be programmed differently depending on your goals and how you want the exercise to function within the wider programme.
A compound exercise being used partly to develop strength might use fewer repetitions than an accessory exercise intended primarily to provide additional muscle-building work.
So, How Many Reps Should Men Over 40 Do?
There is no single best rep range for men over 40.
If maximising strength is your priority, relatively heavier resistance deserves an important place in your programme. The evidence consistently shows greater maximal-strength improvements with heavier loading.
If building muscle is your priority, you have considerably more flexibility. Muscle growth isn’t restricted to the traditional 8–12-rep range, and useful hypertrophy can occur across a broad spectrum of repetitions when the training provides sufficient challenge.
And if you want both muscle and strength?
You don’t need to choose one number.
A sensible programme can combine heavier strength-focused work, moderate-repetition training and higher-repetition accessory work according to the exercise and its purpose.
The important thing is not whether you perform exactly 6, 10 or 15 repetitions.
It’s whether your training is appropriately challenging, whether you can recover from it and whether you’re progressing over time.
Your age doesn’t assign you a rep range.
Your goals, exercises, training experience, effort and ability to progress matter more.
Choose rep ranges for a reason.
Then make those reps count.
Smart. Sustainable. Strong for Life.
Over Lifestyle
Disclaimer
This article provides general fitness information for educational purposes only. It isn’t personalised exercise, medical or rehabilitation advice. Exercise suitability varies according to individual experience, health, injury history and circumstances. If you’re starting strength training, returning after a significant break or making substantial changes to your programme, consider seeking guidance from an appropriately qualified fitness professional. If you have a medical condition, injury, significant pain or concerns about starting or changing an exercise programme, seek advice from an appropriately qualified healthcare professional.
For further information about how Over Lifestyle approaches health and fitness content, read our full disclaimer here.
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