One of the most common questions among lifters is figuring out exactly how much volume or how many sets one should do in a workout. On one hand, some say that doing a few sets close to failure is sufficient for muscle growth and doing too much can cause injury, overtraining, and excess fatigue. On the other, others say that the more volume, the more gains. Which is right and which is wrong?

The short answer is that there is no one-size-fits-all answer as different training frequency may work better for others. The long answer? Here we will look at some evidences to find out how many sets you should do to optimally build muscle.

*Figuring out the optimal volume (sets and frequency) of training can be tricky for many.*

What does Research say?

But first, what is a set? I would define a set for hypertrophy (or muscle-building) as one with 6-15 reps taken close to failure with high effort. This means that warm-up sets are not counted. Anything less than 6 reps would be more strength-focused, while anything more than 15 reps would be endurance-focused.

On Number of Sets

There are research to show that increased number of sets will increase muscle growth, for obvious reasons. For example, in a research by Krieger in 2010, there is 80-85% increase in muscle growth for 4-6 sets compared to 1 set of the same exercise in the same session. A more recent research showed the following:

1-4 sets/week: 5.4% muscle gain
5-9 sets/week: 6.6% muscle gain
10+ sets/week: 9.8% muscle gain

With that, it can be easy to think that there is a dose-response relationship between volume and muscle growth - the more volume, the better, so just do as much as possible. However, it actually isn’t so straightforward. There seems to be an upper limit of the volume that one can go before recovery is impeded. This happens when you experience Central Nervous System (CNS) fatigue before fully activating your muscle, which has been shown in research. Therefore, researcher Mike Israetel estimated the upper limit to be about 20 sets per muscle group per week before any extra sets would not be worth the increased wear and tear, while volume lower than 10 sets per muscle group per week would yield slow gains at best. These would vary between individuals.

How do you know what is the sweet spot for you? If you’re doing 15 sets per muscle group per week and find that you’re constantly burnt out, you might want to take a step back and reduce the number of sets to 10. On the other hand, if you feel like your body is not responding well to the number of sets you are doing, and that you are not too fatigued from training with room to bump your volume up, consider increasing the number of sets to 20.

Research lately indicated that going for more than 20 sets may show better growth in muscle mass, but it isn’t conclusive yet. Moreover, they can be quite exercise-specific. Certain exercises like a heavy deadlift can be damaging and affect recovery more than others. Thus, this is not an endorsement for beginners to do as many sets as possible.

*Too much volume can affect recovery and may not be worth the extra effort.*

On Frequency of Training

Research looking at 7 studies has shown that hitting each muscle group at least twice a week will maximize muscle growth. This research is fairly accurate as variable such as workout volume, exercises and rest times were kept constant. Another study by Schoenfeld et al. was done recently in 2019 whereby 1 group of trained men did a 16-set squat session in a week while another group of trained men did two 8-set squat sessions in the same week. The group that did two 8-sets squat sessions in a week showed benefit to muscle strength and endurance, suggesting that too much volume for a muscle group in a single session is likely not as optimal as splitting the sessions into two.

On the other hand, training each muscle group too often may be detrimental to your growth. For example, this study showed that training each muscle group 4 times per week actually yielded less gains than training each muscle group 2 times per week.

What does it Mean for You?

Use the right training frequency (10 to 20 sets per muscle group per week with each set close to failure, while adjusting progressively) and spread them out 2-3 times per week. Don’t do too much volume in one workout, as it will affect the quality of your sets as well as recovery.

I’ll illustrate it with an example. Say you plan to perform 14 sets per week for shoulders. Split these 14 sets into 2 training days, with 7 sets per day. A good way is to split your workout into 2 upper body and 2 lower body days per week, doing shoulders on both upper body days. Sets can be performed with better quality and you will still be able to hit the optimal sets per week. This will lead to better gains and faster recovery in the long run. If you’re too tired after the week, you might want to cut back to 12 sets per week. If you feel like you have room to increase volume, considering doing 16 sets per week instead.

Always keep in mind that research is applicable for the majority. but each individual responds differently. Some can respond better to higher training volume, while others respond to lower training volume. Factors such as training level, genetics, sleep, diet and gender will determine the optimal training volume. You can use the guidelines shown above for a start, but adjust accordingly to how your body responds.

As you get more advanced, it is recommended that you start training more frequently to increase muscle growth. In this study over 10 weeks, a group of trained men showed increased muscle growth in a 4-days per week upper and lower body split workout, compared to another group which trained full body 3-days per week.

However, remember that the research above has shown what is optimal for muscle growth. If you have limitations to train each muscle group at least twice a week, you still can gain muscle training once a week, just that it will not be as fast. Consistency and sticking to your workout is still the most important!