Volume is the key driver of muscle growth. If you want to build muscle as fast as humanly possible, you need volume, and lots of it.

Volume, volume, volume.

As far as size gains are concerned, volume is the undisputed king.

Or at least, that’s what some people will tell you.

In fact, some folks do just fine with a relatively small number of sets, while others need higher volumes to maximise muscle growth.

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Training Volume and Hypertrophy

There was an interesting study, published in the Journal of Physiology, which looked at the effect of training volume on hypertrophy in some depth [1].

Although there was a lot that went on in this study, I want to focus purely on changes in muscle size, which was measured in the quads using magnetic resonance imaging (MRI).

Here’s how the study was set up:

Subjects (a group of healthy but untrained men and women) did 12 weeks of full-body resistance training, lifting weights 2-3 x per week.

For their quads, they did the leg press and leg extension, performing either one set or three sets per exercise.

In total, the low-volume condition involved 4-6 sets per week, while the moderate-volume condition involved 12-18 sets per week.

With the leg extension and leg press, both legs are normally trained together. But in this trial, the subjects trained one leg at a time, which meant that each side could be trained with a different number of sets.

When you use different groups of people to compare training programs, the food they eat, the life they live, and the genes they were born with can skew the results. But with the “unilateral exercise model” as it’s known, nutrition, lifestyle and genetics are identical for both legs.

The result?

More Sets = More Muscle

On average, more sets led to faster muscle growth. The leg trained with 12-18 weekly sets grew by a little over five percent, compared to almost four percent in the leg trained with a lower volume.

So, there was a muscle-building advantage to the higher volume of training. However, doing three times more work didn’t lead to three times the gains. Put differently, there wasn’t a one-to-one relationship between weekly set count and muscle growth.

There’s more.

Of the 34 subjects taking part in the study, 13 displayed clear benefits of the higher training volume on muscle growth.

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 a smaller number of sets.

Trained versus Untrained Subjects

It was a similar story in a 2018 study, which looked at the effect of different training volumes on muscle growth, this time in trained rather than untrained subjects [2].

The researchers employed three different training volumes – low, medium and high. The low volume group did one set per exercise, the medium volume group did three sets, while the high volume group did five sets.

On average, it was the high volume group that saw the biggest gains in muscle thickness, followed by the medium and then the low volume group.

However, looking at group averages tends to mask individual differences in size gains. Drilling deeper into the results shows large differences in muscle growth from person to person.

Individual Variation in Response to Training Volume

Take a look at the figure below, which shows how the biceps grew in response to the eight-week training program.

The circles represent individual changes in muscle thickness in the biceps after two months of training, while the horizontal bars represent the group average.

As you can see, there were large individual differences in results.

In fact, some subjects in the low-volume group gained muscle faster than subjects in the high-volume group. They got better results with a lot less work.

Final Thoughts

High volume training is the way that most bodybuilders trained in the 60’s, 70’s and 80’s. Things changed in the 1990’s, when high-intensity training – characterized by shorter workouts comprising fewer sets – became popular.

Now the training pendulum has swung back in the direction of high volume again.

Truth is, some people thrive on higher training volumes, while others do better with less – muscles can respond to both approaches.

You may be one of those people who does just as well (if not better) with a relatively low volume of training, which can end up saving you a lot of time in the gym, as well as sparing your joints.

Bottom line?

While you need some volume for muscle growth, too much is going to hinder your progress, and too little will have the same effect.

But what constitutes “too much” or “too little” is not the same for everyone. Just because a particular style of training works well for some people, or happens to be fashionable, doesn’t necessarily mean that it’s right for you.