Volume Vs. Intensity: Which Matters More for Building Muscle? (2024)

There are a few non-negotiables when it comes to your training programme for hypertrophy — firstly: progressive overload, secondly: volume and intensity. But it takes a more discerning lifter to know which of the two to prioritise and how to apply them best in their own training. Now, with new research shedding light on the topic, we break down the evidence and how it can be applied to your own muscle building goals.

Training volume refers to the total amount of work done in a given time frame, whether that be session volume or weekly volume. It is typically calculated as the total number of sets multiplied by the number of reps performed at a given weight. As a calculation it is:

Volume = Sets x Reps x Weight

Intensity is the amount of effort you put into each set at a given load. It is often expressed as a percentage of your one rep max (1RM), however it can also refer to your perceived exertion. As a calculation it is:

Intensity = (Weight Lifted / 1RM) x 100

Volume is the total amount of work done, while intensity is how heavy the weight is relative to your maximum possible exertion. Both have merit for different goals:

If your primary goal is to build muscle: prioritise volume first

If your primary goal is to gain strength and power: prioritise intensity first

According to a new systematic review, increasing volume is key for maximising muscle growth. It found that the best results came from 30-40 sets per muscle per week. However, there is also a minimum effective dose of 4 sets per muscle group per week and somewhere around 10-20 sets per week is still a great goal for muscle growth. It's important to note that above this point isn't for everyone. If you want to absolutely maximise muscle growth: 30-40 sets is where it's at (if that suits you and your body). This could also include indirect exercises that hit the same muscle, eg pull-ups that still hit your biceps.

On the topic of volume, researcher Dr. Milo Wolf explains, 'There is such an amount of volume where you see some hypertrophy but not your best, and that might be around one to three sets. That would be the start of that inverted U relationship. As you increase volume you will see more growth, you kind of climb up that inverted U and you see more growth as you do more volume. But theoretically there then comes a plateau. Where doing more volume past that doesn't necessarily increase growth anymore, it just kind of gives you the same growth.'

Wolf explains, 'More volume leads to more growth, and we have studies looking at pretty high volumes. I recently looked at the research myself as well, and we have around eight studies looking at high volumes in excess of 20 sets per week per muscle. That's what is categorised as extremely high volumes for most people. And when you look at all of these studies, a few dozen studies, as I mentioned, you see that going up in volume from say 10 sets to 30, or even 40 sets, leads to more growth.'

As always, choose a volume that suits your preferences and limitations, but if you can increase your weekly volume: that will lead to greater muscle growth.

The answer to this is a little more nuanced, when it come to the best loads to build muscle, more weight doesn't necessarily equal more muscle gains. Also, there is a chance you might not be lifting heavy enough. However, there is a sweet spot when it comes to the best loads to build muscle.

According to exercise scientist Dr. Mike Israetel PhD, 'The fundamental stimulus of muscle growth seems to be muscle tension — force transduced through and by the muscle fibres.' He continues to explain that while there are other factors at play, 'Tension is king'.

'Tension needs time of application to be effective. One rep of very high tension like your one rep max curl will absolutely stimulate some muscle growth but it's a teeny teeny amount. If you do two reps, that's way more growth, and three and four and five etc is more, and more, and more growth as you do more and more reps.'

He continues to explain that heavier weights equal lower reps, which means more growth per rep, but fewer reps per set. So fewer than five reps per set won't grow as much muscle as sets of at least 5 reps worth of tension stimulus. Using this theory, anything over roughly 85-90% of your one rep max (give or take), would likely not be the most direct route to building muscle at higher intensities. It will still cause some muscle growth, but not as much.

On the other hand, lower intensities will allow far more reps, however that doesn't necessarily equal more muscle growth on the very high rep ranges and low load ends of the scale. Israetel explains, 'You get more opportunities to stimulate tension but more reps of stimulating the tension mechanisms of muscle growth. But each rep comes in less like a scream more like a whisper so all of a sudden you got 25 reps of curls, every single one of those reps wasn't really that muscle growth promoting.'

He concludes that intensities that allow for anything north of 30 reps per set don't grow as much muscle. He adds that hard sets of 5-30 reps grow the most muscle. So whatever intensities allow your reps to fall in that range, close to failure at the end of those sets, will be the sweet spot for muscle growth. Sets of less than five reps, and sets of 30 upwards, do still build muscle, but notably less.