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“I’m cutting so I’m doing more repetitions” is a statement you often hear. But is it really necessary to do more repetitions during cutting? Does it have benefits? Does it have drawbacks?
‘Cutting’
When people are ‘cutting’, they actually want two things at the same time:
- Losing fat
- Building and maintaining muscle mass.
In this article, I will briefly discuss what is needed for these two body changes, after which I will link it to the number of repetitions per set during your training. Ultimately, to be able to answer the question of whether it is necessary to do more repetitions during cutting.
What is needed for fat loss?
An energy deficit, also known as a negative energy balance
In other words, you need to consume less energy than you expend. You can do this in two ways:
- Consume less energy: eat fewer calories.
- Expend more energy: move more.
Both strategies lead to the same effect: an energy deficit.
So, you can lose weight without changing your training. Read that again:
for fat loss, you don’t need to change your training. It can be useful in certain situations. For example, if you’ve been eating very little for a long time and you can’t increase your deficit by adjusting your diet because you would otherwise risk nutrient deficiencies. This story doesn’t apply to 9/10 people.
Furthermore, an adjusted diet has been found to be more effective for fat loss for many people than exercising more.
What is needed for muscle building?
Fat loss is one part of the story. During cutting, you not only want to lose fat but also maintain or even build muscle mass.
Several things are needed for this:
- The right nutrition: so that the building blocks are present to build muscle mass.
- Enough rest: so that your body has time to use the building blocks.
- The right training stimulus: so that your body is stimulated to build muscle mass.
I will leave out the first two points in this article, we assume that these are in order. What I want to talk about is the training stimulus.
What is a proper training stimulus?
You want to stimulate your body in such a way that it builds muscles. Therefore, even during cutting, you want to continue focusing on muscle building. If you don’t, you increase the chance of losing muscle mass. That’s the last thing you want.
I won’t explain how to create a proper training schedule now, as that is beyond the scope of this article. I will only talk about the number of repetitions you perform per set here.
The question now is: how many repetitions are necessary for muscle building?
How many repetitions for muscle building?
Something you often hear people say is that 1 to 6 repetitions are for strength, 6 to 12 repetitions are for muscle mass, and 15+ repetitions are for endurance. Or something similar…
Is this true? Yes and no. No, it’s not that black and white. And yes, there’s some truth to it.
It’s true that the number of repetitions influences the changes that occur in your body. Simply put: the number of repetitions determines whether you mainly work on your endurance, strength, and/or muscle building.
In the literature, extensive research has been done on what kind of changes take place in different repetition ranges. The truth is that it’s more nuanced than the prevailing thought:
In short, you could say that with 1 to 5 repetitions, the focus is slightly more on strength, and from 6 to 15, everything is pretty much equal in terms of muscle growth. So, you can grow well with both 6 and 15 repetitions.
Knowing this, the main question still hasn’t been answered: should you do more repetitions during cutting?
The difficult thing is that the question is vague: what is more? 1 repetition? 100 repetitions?
If you’ve understood the above story, it’s generally not wise for muscle building/maintenance to do more than 15 repetitions. Anything above 15 repetitions could be seen as endurance work, which is not what you want to train as it increases the risk of muscle loss.
However, keep in mind that this is a very generic statement.
The optimal number of repetitions for muscle building varies from person to person, muscle group to muscle group, and exercise to exercise. So, what I just told you can be seen as a rough indication and not a strict dividing line.
So; should you do more than 15 repetitions because you’re cutting? No, unless you want to lose muscle mass.
Do you burn more calories with more repetitions?
Everyone knows that you have to move to expend energy. One possible thought to do more repetitions during cutting is that you move more, which burns more calories, resulting in more fat loss.
Is this line of thought correct? Well, there are a number of caveats…
The question we need to answer is how many more calories you burn with 8 repetitions versus 15 repetitions. I chose 8 repetitions because it’s on the low end of the standard, and you don’t want to do more than 15 repetitions as it increases the risk of muscle loss (discussed above).
Let’s think logically for a moment.
A guy who’s 1 meter 80, 80 kg, 25 years old, with a body fat percentage of 15%, burns about 250 kcal on average with an hour of strength training. If that person now keeps everything in his training the same and goes from 8 to 15 repetitions, it’s not the case that he suddenly burns an additional 250 kcal per training session (500 kcal total). This person burns about 670 kcal with an hour of running. If you think logically, you know that you burn more calories with an hour of running than with an hour of strength training, where you do 15 repetitions and take 2 minutes of rest between sets.
The exact difference in energy expenditure between 8 and 15 repetitions is very difficult to determine because:
- The more repetitions you do, the lighter the weight you use.
- The fewer repetitions you do, the more sets you perform because you still need to do a certain amount of work to continue growing.
- The fewer repetitions you do, the less time your muscles are under tension compared to more repetitions.
- The more repetitions you do, the faster you generally perform the repetitions because you use less weight.
- There’s a difference in energy expenditure between exercises. You don’t burn as much energy with 12 repetitions of squats as with 12 repetitions of unilateral bicep curls. Squats involve many more muscles.
In an American study, the difference in energy expenditure between 10 repetitions and 5 repetitions was investigated for the squat and bench press [1]. In the conclusion, they say they didn’t find a significant difference in energy expenditure between the different protocols. A look at the data shows that there’s a difference of +/- 10 kcal in total energy expenditure between the different protocols. If I were to make a reasoned estimate now, you would burn about 50 kcal more with more repetitions during a regular training. Again; this is a very rough estimate!
To put this into perspective…
Suppose you train 4 times a week. 4 x 50 = 200 kcal per week.
To lose a kilogram of fat, you need to burn 9000 kcal. By increasing the number of repetitions, you burn an extra 200 kcal. That’s equivalent to 20 grams(!) of fat.
You don’t need to do more repetitions because you’ll lose fat faster. It’s easier to just take one less bite at dinner.
More repetitions reduce the risk of injuries
The only valid reason I see to adjust your repetition ranges during cutting is because it reduces the risk of injury.
By doing more repetitions, you automatically lower the weight you use. Maintaining correct technique is easier with a lower weight, reducing the risk of injuries. Especially during cutting, this can be useful because your recovery may be less due to the energy deficit.
Everything summed up:
- Fat loss is a matter of creating an energy deficit. Training can contribute to this, but it’s not the case that if you go from 8 to 20 repetitions, you’ll magically start losing fat.
- If during your cut, the goal is also to lose as little muscle mass as possible, it’s wise not to do more than 15 repetitions. If you do, you’ll train more towards endurance and less towards muscle building.
- This increases the risk of muscle loss. The aim is to stay within the 5 to 15 repetitions range. By increasing your repetitions from 8 to, for example, 15, you’ll probably only burn a few tens of calories more, which is a negligible effect compared to the big picture.
- Performing more repetitions can reduce the risk of injuries. Due to the lighter weights, it’s easier to maintain the correct technique.
Stop using the term ‘cutting’
I think the biggest confusion about the number of repetitions has arisen from the term ‘cutting’. It implies that you need to train differently to get lean.
While you now know that’s not necessary at all…
References
- MAZZETTI SA, WOLFF C, COLLINS B, et al. Influence of Differences in Exercise-intensity and Kilograms/Set on Energy Expenditure During and After Maximally Explosive Resistance Exercise. International Journal of Exercise Science. 2011;4(4):273-282.
