What is a Cluster Set?
A cluster set is a set where the total number of reps is broken down into smaller clusters of reps and split apart with short periods of intra-set rest.
For instance, instead of performing 9 reps in a constant repetition fashion, you could perform the set in 3 clusters of 3, with a short rest between them.
The idea behind a cluster is that you would perform a set you could normally perform with continuous reps, but with short breaks throughout.
What are the Benefits of Cluster Sets?
Basically, the intra-set rest allows you to attenuate fatigue accumulation throughout your set. This allows you to keep load higher for clusters, keep the concentric portion of the fast (practice power), and possibly do more reps before failure.
Power Practice
Quite simply, your 12th rep in a set is never going to be as fast or powerful as the preceding reps when you have no rest. By simply resting in between reps, you can manage fatigue to generate more power. Consider how most Olympic style weightlifters train their main movements (inherently powerful actions), most of the time there will be a short rest between each rep they perform, rather than continuous reps. This allows for more force in each lift, by managing fatigue.
Be aware though that this can cut the effect of the stretch shortening cycle on power generation, so if you find the first rep hard to perform explosively, but subsequent reps much easier, it may be that you're using the eccentric stretch of your muscles to provide bounce into the next rep.
This sort of training is good for inherently powerful exercises, or that need power to complete correctly.
Technique Practice
You need work on your technique. Most people don't have good technique, and you're most people. As fatigue in a set accumulates, the ability to perform with good technique diminishes, both due to muscular factors as well as mental factors (ugh, so tired). By taking short breaks between clusters of reps during a set you can get quality reps at a substantial volume in a shorter amount of time. Take enough time between reps to prepare yourself for the next cluster and you can really hammer that technique with good focus.
How to Use Cluster Sets
So the idea behind cluster sets is that you avoid failure. You don't even really want to go too close to failure. You manage fatigue to the point that you never really experience momentary muscular failure. This means that cluster training can be sub-optimal for hypertrophy training and even maximal strength training.
Use cluster training for the ideas above (power and technique) either as a training tool for complex or powerful movements, or as boosters for your main strength or hypertrophy movements (I would recommend a 1-4 week block of clusters once you're an intermediate as a novel tool).
Clusters shouldn't really be a main tool in your arsenal, just an accessory once in a while.
In the world of bodyweight fitness, a few uses come to mind:
I think that you should use your intuition a bit and regulate your rest by the effect it has on each cluster. Rest long enough that you can perform with adequate power and/or technique. Rests should ideally stay quite short: about 10-30 seconds.
If you start taking longer rests, it becomes more like Rest Pause Training, a related technique that we will cover some other time (the differences are blurry!)
In between sets you can rest for how long you'd usually rest between sets of the same total size (as long as you need).
Volume and Intensity
There are three main ways I'd expect to see cluster sets progressed:
Working on power and/or technique:
Sorry, no energy to put these in their correct place!
Haff, G. G., Hobbs, R. T., Haff, E. E., Sands, W. A., Pierce, K. C., & Stone, M. H. (2008). Cluster Training: A Novel Method for Introducing Training Program Variation. Strength & Conditioning Journal, 30(1), 67-76. doi: 10.1519/SSC.0b013e31816383e1
Hansen, K., Cronin, J., & Newton, M. (2011). The effect of cluster loading on force, velocity, and power during ballistic jump squat training.
Hansen, K. T., Cronin, J. B., Pickering, S. L., & Newton, M. J. (2011). Does cluster loading enhance lower body power development in preseason preparation of elite rugby union players? The Journal of Strength & Conditioning Research, 25(8), 2118-2126.
Hardee, J. P., Lawrence, M. M., Zwetsloot, K. A., Triplett, N. T., Utter, A. C., & McBride, J. M. (2013). Effect of cluster set configurations on power clean technique. Journal of sports sciences, 31(5), 488-496.
Lawton, T., Cronin, J., Drinkwater, E., Lindsell, R., & Pyne, D. (2004). The effect of continuous repetition training and intra-set rest training on bench press strength and power. J Sports Med Phys Fitness, 44(4), 361-367.
Moir, G. L., Graham, B. W., Davis, S. E., Guers, J. J., & Witmer, C. A. (2013). Effect of Cluster Set Configurations on Mechanical Variables During the Deadlift Exercise. Journal of human kinetics, 39, 15-23.
Moreno, S. D., Brown, L. E., Coburn, J. W., & Judelson, D. A. (2014). Effect of cluster sets on plyometric jump power. The Journal of Strength & Conditioning Research, 28(9), 2424-2428.
Oliver, J., Kreutzer, A., Jones, M., Jenke, S., Phillips, S., & Mitchell, J. (2015). Velocity drives greater power observed during back squat using cluster sets. J Strength Cond Res. doi, 10, 1519.
Oliver, J. M., Jagim, A. R., Sanchez, A. C., Mardock, M. A., Kelly, K. A., Meredith, H. J., . . . Kreider, R. B. (2013). Greater Gains in Strength and Power With Intraset Rest Intervals in Hypertrophic Training. The Journal of Strength & Conditioning Research, 27(11), 3116-3131. doi: 10.1519/JSC.0b013e3182891672
Oliver, J. M., Kreutzer, A., Jenke, S., Phillips, M. D., Mitchell, J. B., & Jones, M. T. (2015). Acute response to cluster sets in trained and untrained men. European journal of applied physiology, 115(11), 2383-2393.
A cluster set is a set where the total number of reps is broken down into smaller clusters of reps and split apart with short periods of intra-set rest.
For instance, instead of performing 9 reps in a constant repetition fashion, you could perform the set in 3 clusters of 3, with a short rest between them.
The idea behind a cluster is that you would perform a set you could normally perform with continuous reps, but with short breaks throughout.
What are the Benefits of Cluster Sets?
Basically, the intra-set rest allows you to attenuate fatigue accumulation throughout your set. This allows you to keep load higher for clusters, keep the concentric portion of the fast (practice power), and possibly do more reps before failure.
Power Practice
Quite simply, your 12th rep in a set is never going to be as fast or powerful as the preceding reps when you have no rest. By simply resting in between reps, you can manage fatigue to generate more power. Consider how most Olympic style weightlifters train their main movements (inherently powerful actions), most of the time there will be a short rest between each rep they perform, rather than continuous reps. This allows for more force in each lift, by managing fatigue.
Be aware though that this can cut the effect of the stretch shortening cycle on power generation, so if you find the first rep hard to perform explosively, but subsequent reps much easier, it may be that you're using the eccentric stretch of your muscles to provide bounce into the next rep.
This sort of training is good for inherently powerful exercises, or that need power to complete correctly.
Technique Practice
You need work on your technique. Most people don't have good technique, and you're most people. As fatigue in a set accumulates, the ability to perform with good technique diminishes, both due to muscular factors as well as mental factors (ugh, so tired). By taking short breaks between clusters of reps during a set you can get quality reps at a substantial volume in a shorter amount of time. Take enough time between reps to prepare yourself for the next cluster and you can really hammer that technique with good focus.
How to Use Cluster Sets
So the idea behind cluster sets is that you avoid failure. You don't even really want to go too close to failure. You manage fatigue to the point that you never really experience momentary muscular failure. This means that cluster training can be sub-optimal for hypertrophy training and even maximal strength training.
Use cluster training for the ideas above (power and technique) either as a training tool for complex or powerful movements, or as boosters for your main strength or hypertrophy movements (I would recommend a 1-4 week block of clusters once you're an intermediate as a novel tool).
Clusters shouldn't really be a main tool in your arsenal, just an accessory once in a while.
In the world of bodyweight fitness, a few uses come to mind:
- Muscle Up technique and power development
- Box Jumps
- Dynamic lever work where form or ROM quickly degrades (e.g front pulls)
- Explosive Pull Up
I think that you should use your intuition a bit and regulate your rest by the effect it has on each cluster. Rest long enough that you can perform with adequate power and/or technique. Rests should ideally stay quite short: about 10-30 seconds.
If you start taking longer rests, it becomes more like Rest Pause Training, a related technique that we will cover some other time (the differences are blurry!)
In between sets you can rest for how long you'd usually rest between sets of the same total size (as long as you need).
Volume and Intensity
There are three main ways I'd expect to see cluster sets progressed:
Working on power and/or technique:
- 1-3 reps per cluster
- 3-8 clusters
- Maintain the same reps and intensity but increase the quality of movement
- 2-4 reps per cluster
- 2-3 clusters
- Either increase the intensity every week, or build reps in the cluster then build intensity
- 2-6 reps per cluster
- 3-4 clusters
- Keep the intensity and reps the same, but work on reducing the rest between clusters, increase intensity once you reach a set level for rest intervals.
Sorry, no energy to put these in their correct place!
Haff, G. G., Hobbs, R. T., Haff, E. E., Sands, W. A., Pierce, K. C., & Stone, M. H. (2008). Cluster Training: A Novel Method for Introducing Training Program Variation. Strength & Conditioning Journal, 30(1), 67-76. doi: 10.1519/SSC.0b013e31816383e1
Hansen, K., Cronin, J., & Newton, M. (2011). The effect of cluster loading on force, velocity, and power during ballistic jump squat training.
Hansen, K. T., Cronin, J. B., Pickering, S. L., & Newton, M. J. (2011). Does cluster loading enhance lower body power development in preseason preparation of elite rugby union players? The Journal of Strength & Conditioning Research, 25(8), 2118-2126.
Hardee, J. P., Lawrence, M. M., Zwetsloot, K. A., Triplett, N. T., Utter, A. C., & McBride, J. M. (2013). Effect of cluster set configurations on power clean technique. Journal of sports sciences, 31(5), 488-496.
Lawton, T., Cronin, J., Drinkwater, E., Lindsell, R., & Pyne, D. (2004). The effect of continuous repetition training and intra-set rest training on bench press strength and power. J Sports Med Phys Fitness, 44(4), 361-367.
Moir, G. L., Graham, B. W., Davis, S. E., Guers, J. J., & Witmer, C. A. (2013). Effect of Cluster Set Configurations on Mechanical Variables During the Deadlift Exercise. Journal of human kinetics, 39, 15-23.
Moreno, S. D., Brown, L. E., Coburn, J. W., & Judelson, D. A. (2014). Effect of cluster sets on plyometric jump power. The Journal of Strength & Conditioning Research, 28(9), 2424-2428.
Oliver, J., Kreutzer, A., Jones, M., Jenke, S., Phillips, S., & Mitchell, J. (2015). Velocity drives greater power observed during back squat using cluster sets. J Strength Cond Res. doi, 10, 1519.
Oliver, J. M., Jagim, A. R., Sanchez, A. C., Mardock, M. A., Kelly, K. A., Meredith, H. J., . . . Kreider, R. B. (2013). Greater Gains in Strength and Power With Intraset Rest Intervals in Hypertrophic Training. The Journal of Strength & Conditioning Research, 27(11), 3116-3131. doi: 10.1519/JSC.0b013e3182891672
Oliver, J. M., Kreutzer, A., Jenke, S., Phillips, M. D., Mitchell, J. B., & Jones, M. T. (2015). Acute response to cluster sets in trained and untrained men. European journal of applied physiology, 115(11), 2383-2393.
