If you want to know what the science says about how many sets your muscles need to grow, both in a single workout and over the course of a week, this page will tell you everything you need to know.
Want a short and simple answer to the question of how many sets you should do in a workout? Here it is:
Depending on how often you’re lifting weights, each workout should comprise around 15-20 work sets in total, with no more than 12 sets for each individual muscle group. For maximum muscle growth, aim for 10-20 sets per muscle group per week, spread across 2-6 training sessions.
However, there are lots of individual factors to consider, which include:
- Your training status (beginner, intermediate or advanced)
- How often you’re lifting weights
- Whether you’re a fast or slow responder to resistance training
- How hard you’re training
There’s no single correct number of sets that’s going to work equally well for all people, all of the time.
In fact, some folks do just fine with a relatively small number of sets per workout, while others, particularly advanced lifters such as bodybuilders, need higher volumes to maximize muscle growth.
Here’s a closer look at what the research has to say on the subject of training volume and muscle growth.
How Many Sets Per Muscle Group Per Week?
When a team of US researchers pulled together all the relevant research on training volume and muscle growth, they found a dose-response relationship between the number of weekly sets you do for a muscle and the speed at which that muscle grows .
Their meta-analysis shows that ten or more sets per muscle group per week worked better than 5-9 sets. And 5-9 sets worked better than four sets or less.
Other research on the subject shows that gains in muscle size tend to flatten out at around 18-20 sets per muscle group per week [2, 3, 4].
That’s not to say higher volumes won’t lead to faster gains. But there is a point of diminishing returns, where you end up expending a lot of extra time and effort, as well as exposing yourself to a greater risk of injury, for a relatively small benefit.
The Optimal Training Volume Varies from Person to Person
Not everyone responds in the same way to an increase in training volume.
Research published in the Journal of Physiology, for example, shows that some people did just as well with a low (4-6 weekly sets per muscle group) as they did with a higher (12-18 weekly sets per muscle group) volume of training .
Of the 34 subjects taking part in the study, 13 displayed clear benefits of the higher training volume on muscle hypertrophy.
However, the rest made similar progress irrespective of how many sets they did. In fact, a few individuals saw faster growth in the leg that was trained with fewer sets. They got better results with a lot less work.
People are different, not just in terms of how fast their muscles grow, but also in the type and amount of training they respond best to.
The “best way” for one person to train may be very different to someone else’s “best way.” Just because a particular amount of training works well for some people doesn’t necessarily mean that your body will respond in the same way.
Beginner, Intermediate or Advanced?
The length of time you’ve been training also has an impact on how many sets your muscles need to grow.
On average, beginners don’t need as many sets as intermediate and advanced lifters (such as bodybuilders) in order to stimulate growth.
If you’re just starting out, 5-10 weekly sets for the major muscle groups will often be enough to stimulate a significant amount of muscle growth.
For example, beginners can make impressive gains on some kind of 3-day full-body workout, where they train the whole body three times a week on non-consecutive days (i.e. Monday, Wednesday and Friday).
But over time, your body adapts, making the acquisition of additional muscle mass progressively slower and more difficult.
To continue gaining size will typically require a higher weekly training volume, which usually entails the addition of an extra training day, and the transition to some kind of body part split routine, such as an upper/lower split.
This involves training four days a week, working the upper body and lower body on separate days.
- Monday: Upper Body
- Tuesday: Lower Body
- Thursday: Upper Body
- Friday: Lower Body
Training Frequency and Sets Per Workout
The number of weekly sets you need to maximize muscle growth also depends on training frequency, which refers to the number of times a week a particular muscle group is trained.
That is, doing 16 sets once a week will produce different results to 8 sets twice a week.
That’s because there’s an upper limit on the amount of stimulation your muscles can respond to in any given workout. And the closer you get to this ceiling, the smaller the return on your investment of time and effort becomes.
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As an example, let’s say that doing 6 sets rather than 3 sets per muscle group speeds up growth by 25%.
But going from 6 sets to 9 sets might increase growth by 10%. A further increase from 9 sets to 12 sets might have no effect at all, with those extra sets representing so-called junk volume.
In other words, the gains become progressively smaller as the number of sets increases. Continue adding sets, and eventually your rate of growth will flatten out.
This is something that’s shown up in animal studies. Research in rats, for example, shows that muscle protein synthesis plateaus after around 10 sets (see figure below), with no further increase after 20 sets .
A follow-up study, this time in humans, also found no additional muscle growth with 12 versus 6 sets per workout .
This time, the researchers took three groups of trained men, and got them to do 6, 9 or 12 sets of squats twice a week.
After eight weeks of training, there was no statistically significant difference between the groups in terms of muscle growth in the quads.
In fact, the group who saw their quads grow the fastest were the ones who did six sets of squats, twice a week.
- Six sets twice a week + 7.7%
- Nine sets twice a week + 6.7%
- Twelve sets twice a week + 6.1%
But to repeat, the difference in muscle growth between the three groups wasn’t large enough to reach statistical significance.
Blitzing your muscles with lots of sets gives you much more of a pump, as well as generating a high level of post-exercise muscle soreness.
But while getting a pump and feeling sore for days after a workout might feel satisfying, it’s no guarantee that muscle is going to be built any faster.
Training Volume and Joint Health
As well as the impact that training volume has on muscle mass, you also need to consider what it’s doing to your joints, which are often the limiting factor when it comes to the number of sets you can handle in the gym.
The benefit of any increase in training volume has to be weighed against the potential negative effect it can have on connective tissue.
This is especially true if you do a lot of heavy lifting with the various compound exercises, such as the squat, deadlifts, bench press and so on. While these exercises are great for building muscle, they’re not always the most “joint friendly” options available.
The last thing you want is to be constantly nagged by various aches and pains in your knees, elbows, shoulders or back.
Pushing your body to the limit can deliver impressive results in the short term. But, in the long run, chances are you’re going to end up getting injured.
Some folks can handle it.
If you have great genetics, age on your side, you’re benefiting from some pharmaceutical assistance, or you’ve spent many years training your body to handle high training volumes, you can get away with it.
Most, however, will be better off with a training volume that’s slightly below what is “optimal” for muscle growth, but one that leaves you feeling fresh, motivated, and free from pain.
Fatigue, Stress and Recovery
You also need to consider what else is going on in your life.
A high volume of training performed against the background of a low-stress, low-fatigue lifestyle will produce very different results to that same volume of training paired with a high-stress, high-fatigue lifestyle.
That’s because non-training stressors have the potential to slow the rate at which you recover from and adapt to your workouts.
Researchers have found that when you’re “under stress,” you recover more slowly after training [8, 9].
In one study, subjects with lower stress scores saw greater gains in the bench press and squat after 12 weeks of training compared to subjects with higher stress scores .
“When athletes are subjected to elevated non-training stressors, physiological training adaptations will inevitably be compromised,” writes John Kiely, former Head of Strength and Conditioning for UK Athletics.
“This will occur regardless of the origin of that stress: whether it be anxiety due to loss of form, exam pressure, relationship turbulence, poor sleep, or corrosive environmental conditions.”
Christie Aschwanden, author of Good to Go: What the Athlete in All of Us Can Learn from the Strange Science of Recovery, makes a similar point:
“To our bodies, physical and emotional stress are both similarly taxing. A good recovery plan takes both kinds of stress into account. One of the most common mistakes athletes make is to discount the stress that their jobs and busy lives place on their bodies. To fully recover, you have to not just take a break from training, you have to find ways to reduce those other stressors too.”
How Hard Are You Training?
The number of sets you need to maximize growth also depends on how hard you train.
Specifically, I’m talking about the number of reps you have left in the tank at the end of each set.
If you finish each set with 3-4 reps in reserve, chances are you’ll need more sets to produce the same amount of growth than someone who pushes each set to, or very close to, muscular failure.
Just because a training program involves a large number of sets doesn’t mean that all of those sets are effective at stimulating growth.
While building muscle doesn’t require taking each set to failure, you do need to train hard and push yourself.
A training program can involve a large number of sets, but if each set is cut short with a large number of reps in the tank, the strength of the “make me bigger” signal being sent to your muscles will be relatively small.
Satisficing vs Maximizing
Psychologists have studied how people make decisions and concluded there are two basic styles.
On the one hand you have the maximizers, who want to feel like they’re doing everything humanly possible to build muscle as fast as nature will allow.
Satisficers, on the other hand, don’t necessarily want to know the best way. Satisficing, which combines the words satisfy and suffice, involves selecting an approach that’s good enough, even if it’s not necessarily the best.
Most advice on building muscle centers around the “best way” to do this or the “fastest way” to do that.
Trying to make progress as fast as humanly possible is fine if training is a big part of your life. But there’s not a one-to-one relationship between the amount of work you put in, and the results you get back.
That is, if you double the amount of training you do, it doesn’t necessarily follow that you’re going to see results twice as fast.
And not everyone is a maximizer who wants to push for optimal. Some folks are happy to do the least amount of work they can get away with, just as long as they’re moving in the right direction.
What’s the minimum amount of strength training you can do, and still see results?
In many cases, a single work set, with a high intensity of effort, performed 2-3 times a week, will get the job done.
Take the example of a study published in the journal Medicine and Science in Sports and Exercise, which looked at how strength training volume affects gains in strength and size .
Three groups of trained subjects lifted weights three times a week on non-consecutive days (Monday, Wednesday and Friday) for eight weeks, doing seven exercises per workout.
- Chest press
- Shoulder press
- Lat pulldown
- Seated row
- Leg press
- Leg extension
One group did a single set of each exercise, hitting failure between 8 and 12 reps. The second group did three sets. The third group did five sets.
Across all the muscles studied – biceps, triceps, and two of the muscles that make up your quads (vastus lateralis and rectus femoris) – the high volume group saw the biggest gains in muscle thickness, followed by the medium and then the low volume group.
In other words, the group doing more work gained the most muscle. But even the single set group saw gains in muscle thickness, albeit to a lesser extent than the 3-set and 5-set groups.
On the strength and muscular endurance side of things, there was no statistically significant difference in results. That’s despite the fact that the single set group trained for just 13 minutes, compared to 70 minutes in the five-set group.
In short, if you don’t have the time (or the inclination) to train in such a way that you’re maximizing your progress, one hard set per exercise (ideally preceded by a number of submaximal warm-up sets), performed 2-3 times a week, should be enough to keep the gains coming.
Compound vs Isolation Exercises
Smaller muscle groups like the biceps and triceps don’t need as many sets, mainly because they’re involved when you use compound lifts to train other body parts.
Pressing exercises, for example, work the muscles in your chest and shoulders. But the triceps are also involved at the same time.
They’re still going to receive some growth stimulation even if you did nothing but the bench press and overhead press, and skipped the isolation exercises.
The same applies to the biceps, which get an indirect growth stimulus with every chin-up, pulldown or row you do.
Training for Hardgainers
For people who have a hard time building muscle – the so-called hardgainers of this world – increasing your training volume may be just what you need to get your muscles growing.
As long as your overall training program is set up properly, gradually ramping up your training volume over time may well deliver better gains than going in the other direction and doing less.
This has been seen in research on endurance exercise, where low responders to a particular exercise program see better results when they switch to a higher volume of training.
In one study, subjects who saw little or no gains in cardiovascular fitness following a six-week low-volume training protocol made much better improvements when they upped the dose of training .
In fact, none of the participants were classified as “non responders” after the higher volume of exercise.
In much the same way, higher training volumes may help slow responders see a more “normal” muscle-building response to lifting weights.
A practical way to do so is with the use of short specialization cycles, where you bump up the amount of work you do for certain muscles to make them grow faster.
If you tried to do it for all muscles at the same time, the overall training stress would be too much.
For 1-2 muscle groups at a time, it’s doable. But not for your whole body.
How to Build Your Own Workout Routine
There’s a theoretical “optimal” number of sets per muscle group, above and below which gains in muscle size will be slower than they otherwise would be.
Put differently, you need some volume for muscle growth. Too much is going to hinder your progress, while too little will have the same effect.
However, the precise location of this “sweet spot” will depend on your genetics, the length of time you’ve been training, your age, the exercises you’re doing, the muscle group in question, and how much effort you’re putting into each set.
It will also shift over time in response to changes in diet, sleep, and stress levels. Your tolerance for volume won’t be as high when you’re busy, short on sleep and not recovering as well.
The challenge comes when deciding exactly where that sweet spot is.
If you’re trying to gain muscle as fast as humanly possible, chances are you’re going to see better results with at least 10 sets per muscle group per week than you will with 5-9 sets. For some people and in some muscle groups, even higher training volumes may be useful.
But there will also come a point of diminishing returns, where you end up expending a lot of extra time and effort, as well as exposing yourself to a greater risk of injury, for a relatively small benefit.
Ideally, you want to find a training volume where your repetition strength is increasing, you don’t feel tired and worn out all the time, and the workout routine is one you can stick to. An optimal workout routine is not an optimal workout routine if you don’t have time to do it.
I can’t tell you exactly how many sets to do, and nor can anyone else. Research can point the way, but it only tells you the average response in a group of people.
That’s why it’s important to experiment. And the logical way to go about doing so is to start out with a lower training volume and gradually work your way up. Don’t just jump in and double your set count overnight.
Gradually ramping up your weekly set count over time will let you see if the increase in volume makes enough of a difference to justify the time and effort involved in doing so.
Frequently Asked Questions
Yes, sets of 20 can be used to build muscle. Lower reps with heavier loads do tend to increase strength gains compared to high reps and lighter loads. However, studies show that it’s possible to stimulate hypertrophy by training in the 5-8 rep range, the 8-12 rep range, or even using very light loads in the 20-30 rep range.
In most cases, 30 work sets in one workout is going to be too much. As your set count goes up, so does the amount of time you spend in the gym, and most people don’t have an unlimited amount of time to devote to training.
What’s more, the longer your workouts last, the more likely it is you’ll run out of steam towards the end of a training session. The muscles being worked later in that training session aren’t going to receive the same level of effort as the ones trained at the start.
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