There are multiple workout variables to take into account when it comes to improving power, strength, and size. Possibly the biggest variable when aiming to accomplish one of them or all of the goals is continual, progressive overload. This is the art of applying a calculated progressive stimulus on the body while simultaneously avoiding burnout.
It’s a no-brainer, but an increase in volume at a certain intensity is one of the best ways to track improvements in the gym. One way to increase your total load in workouts is with cluster sets/training. Here’s what you need to know.
Cluster Sets Explained
Cluster sets are smaller sets built-in a larger set with rest increments that range from 10-30 seconds. When you typically think of a set, you think of doing one rep immediately after another until you complete all of the prescribed reps. Clusters sets look like this: Do three reps, rest 30 seconds, do three reps, rest 30 seconds, do three reps. That entire sequence is one set.
The main benefit of cluster sets is that you can lift more weight for the same overall volume. If you were to do deadlifts for a straight-set of eight reps, you could only lift with, say, 75 percent of your one-rep max (1RM). But, breaking that set up into four clusters of two reps allows you to use closer to 90 percent of your 1RM for the same amount of overall volume. For that reason, it’s a popular technique among strength athletes such as powerlifters.
What Does Cluster Training Look Like?
Cluster sets can take different forms, and there isn’t a one-size-fits-all cluster set structure. That said, you can program cluster sets for any of the three main training adaptations — power, strength, and hypertrophy. Typically, cluster sets are used for compound movements since they’re meant to increase the load on the bar, and multi-joint exercises let you use more weight. However, while less common, you can also use cluster sets for accessory exercises.
You should acknowledge four variables before beginning to program clusters — inter-set rest intervals, total reps per set, total rest, and intensity.
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Inter-Set Rest Intervals
The normal inter-set rest interval for cluster sets ranges from 10-30 seconds. These intervals will vary depending on your goals, intensity, and total work. If that’s confusing, then below is a list of a few scenarios with potential inter-set rest guidelines.
- Power: 15-30 second rest intervals
- Strength: 10-30 second rest intervals
- Hypertrophy: 10-20 second rest intervals
What’s most important when figuring out rest for your cluster sets is gauging your capabilities for moving weight efficiently and safely. For example, if you’re missing reps due to the limited rest, then scale back the weight or slightly increase your rest interval.
Total Reps Per Set
The next variable we’ll look at is the total reps you plan to perform for each cluster set. This is where cluster sets look similar to what you probably already know about traditional reps for training adaptations. The only real difference is how you plan to break up the smaller subsets within the total reps. Check out the examples below.
- Power: 4-5 total reps, so a cluster could look like: 2-2-1 or 2-1-1
- Strength: 5-7 reps, so a cluster could look like: 2-2-1 or 3-2-2
- Hypertrophy: 8-10 reps, so a cluster could look like: 3-3-2 or 4-3-3
As you can see, the smaller subsets are all similar (one to four reps), but they equate to a larger set, which correlates with a traditional set’s goals. In this scenario, power is a little bit extrapolated compared to traditional sets due to the smaller subsets.
The next variable to consider is the total rest taken between cluster sets. One of the main focuses of cluster sets is accomplishing a certain amount of work in different time allotments. This being said, your rest in-between sets can be paramount to successfully using these, as too little will equate to fatigue accumulation, form breakdown, and failed reps.
- Power: 2-3 minutes
- Strength: 1-3 minutes
- Hypertrophy: 1-1:30 minutes
Rest in-between sets will be similar to what traditional sets look like. Ideally, take the rest you need to get in the work without missing reps or dropping intensities.
The final variable for programming successful cluster sets is choosing an intensity. This is the variable where coaches and athletes will most likely have the most variability. When working at higher intensities, it’s going to be tough to accurately provide you with perfect numbers below, as everyone’s workload typically varies most at higher percentages.
- Power: 8-9 RPE or 90%+ of your 1RM
- Strength: 7-8 RPE or 75-85% of your 1RM
- Hypertrophy: 6-8 RPE or 70-80% of your 1RM
These numbers will vary depending on your training goal and capabilities, so please, take these as general guidelines, not an end-all-be-all solution.
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Examples of Cluster Sets
Below are three examples of what cluster sets/training could look like when training for power, strength, and hypertrophy.
- 3 x 5 (2-2-1) — 15-second rest in-between each subset, 90% 1RM intensity, and 3 minutes total rest between sets.
- 2 x 4 (2-1-1) — 20-second rest in-between each subset, 93% 1RM intensity, and 4 minutes total rest between sets.
- 4 x 6 (2-2-2) — 15-second rest in-between each subset, 85% 1RM intensity, and 3 minutes total rest between sets.
- 3 x 8 (3-3-2) — 10-second rest in-between each subset, 80% 1RM intensity, and 2.5 minutes total rest between sets.
- 4 x 8 (3-3-2) — 10 second rest in-between each subset, 77% 1RM intensity, 2 minutes total rest between sets.
- 3 x 10 (4-3-3) — 5-second rest in-between each subset, 75% 1RM intensity, 2 minutes total rest between sets.
How to Program Cluster Sets
After looking at the different schemes you can do with cluster sets above, let’s dive into the specifics of programming cluster sets for individual movements. In the examples below, we’ll be looking at a program plan for each muscle group to improve your size.
- Barbell bench press: 4 x 8 (3-3-2), 10-second rest in-between each subset, 77% 1RM intensity, 2 minutes total rest between sets.
- Barbell overhead press: 3 x 10 (4-3-3), five-second rest in-between each subset, 75% 1RM intensity, 2 minutes total rest between sets.
- Barbell bent-over row: 4 x 8 (3-3-2), 10-second rest in-between each subset, 77% 1RM intensity, 2 minutes total rest between sets.
- Barbell squat: 3 x 10 (4-3-3), five-second rest in-between each subset, 75% 1RM intensity, 2 minutes total rest between sets.
To make cluster sets worthwhile, you’ll only want to perform them on the first exercise — a compound movement — of each workout. That’s because what separates cluster sets from other regular sets is the ability to be fully rested to enable you to lift the most amount of weight possible. If you wait until you’re already a few exercises into your workout, your muscles will be fatigued, hindering the enhanced strength and power you receive from cluster sets.
You can include the same movements; you’ll need to alter the rest and reps to the power and rest variables mentioned earlier in this article.
When to Program Cluster Sets Into Your Training
You’ll want to program cluster sets into your training plan if you’re an explosive athlete, such as a powerlifter or sprinter. However, you’ll also want to give them a go if you’ve plateaued on a big compound movement, including barbell bench press, barbell squat, and barbell military press.
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With that being said, cluster sets are meant for compound movements, not isolation movements — dumbbell curls, triceps extensions, and lateral raises — that’s because the whole point in utilizing cluster sets into your training program is to improve your power and strength, which is best for the big movements.
Save isolation movements for other training methodologies, such as drop sets, ramp sets, and burnout sets.
The Benefits of Cluster Sets
A few benefits come with utilizing cluster sets, and these benefits will vary slightly depending on your goal and usage of them. Below are four potential benefits to programming cluster sets in your training.
A review of cluster sets in The Journal of Strength and Conditioning Research asserts that cluster sets can reduce fatigue in a training session, leading to more consistent performance in the gym. (1)
More Total Volume
We discussed it above, but working with higher intensities can create a limitation when aiming to hit higher reps. Cluster sets work to displace work over smaller sets, allowing an athlete to hit more reps at a greater intensity. A 2015 study in the European Journal of Applied Physiology demonstrates that cluster training compared to traditional sets promoted greater total work volume and higher average power. (2)
May Help Increase Strength
More research compared subjects who followed traditional sets (4 x 10) and intra-rest interval sets (8 x 5) throughout 12-weeks. Authors found that both groups increased their strength in the tested lifts and saw a shift in muscle fibers, but the intra-rest set group saw slightly greater increases in strength. Although, researchers note that this could be due to the groups shifting their 1RMs every four weeks, thus allowing the five-rep group to increase quicker, as it’s fewer reps per set. (3)
Greater Total Power
One way to measure power is your ability to lift heavy weights as fast as possible. Since cluster sets have you lift fewer reps at a time and rest more than traditional sets, you’ll be able to lift heavier weights at a faster rate, skyrocketing your power output.
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Cluster sets can be a useful tool for increasing one’s total work and volume during a workout. They allow for the potential to perform more reps with certain percentages while attempting to avoid form breakdown. Is there a one-size-fits-all cluster set format? Not necessarily, although the variables that makeup cluster sets should be kept consistent to avoid misuse of their meaning/structure.
- Tufano, James & Brown, Lee & Haff, Guy. (2017). Theoretical and Practical Aspects of Different Cluster Set Structures: A Systematic Review. Journal of Strength and Conditioning Research. 31. 848-867. 10.1519/JSC.0000000000001581.
- Oliver JM, Kreutzer A, Jenke S, Phillips MD, Mitchell JB, Jones MT. Acute response to cluster sets in trained and untrained men. Eur J Appl Physiol. 2015 Nov;115(11):2383-93. doi: 10.1007/s00421-015-3216-7. Epub 2015 Jul 17. PMID: 26183257.
- Oliver, Jonathan & Jagim, Andrew & Sanchez, Adam & Mardock, Michelle & Kelly, Katherine & Meredith, Holly & Smith, Gerald & Greenwood, Mike & Parker, Janet & Riechman, Steven & Fluckey, James & Crouse, Stephen & Kreider, Richard. (2013). Greater Gains in Strength and Power With Intraset Rest Intervals in Hypertrophic Training. Journal of strength and conditioning research / National Strength & Conditioning Association. 27. 10.1519/JSC.0b013e3182891672.
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