Complete guide to cluster training for strength and muscle size

Complete guide to cluster training for strength and muscle size

Using cluster sets for strength gains is one of my absolute favorite methods. Even though cluster training has been around for decades, they seem to be too much of a forgotten tool in modern strength training and with the rise of evidence-based strength training, cluster training is often overlooked, even though there is some research supporting its effectiveness. Most of that is on power development, but clusters have a massive potential in increasing your strength capacity as well.

There are a tons of fitness tips and tricks that simply are gimmicks. Clusters are not one of them. Though it might seem like one for sure. Someone might claim: “Gain 5 kg on your bench press instantly!” promoting cluster sets and it wouldn’t be too far from the truth. Cluster sets do allow you to lift more weight, when compared to regular straight sets. And there is a simple explanation to this.

When you lift something heavy and you lift it over and over, your muscles and nervous system start to fatigue, and once fatigued enough, you cannot lift that weight any longer and you need to put the weight down. After a break you can continue lifting again, because your muscles and nervous system are recovered and can produce high forces again. A little trick you can do, what makes cluster sets so effective, is that you allow your body to take short breaks during the sets, in order to lift higher loads. 

Lets dig a bit deeper into what cluster sets really are. 

Usually you start your set, do a certain amount of reps, lets say ten reps for example, you go hopefully close to failure, and then you rack the weights and rest. This type of set is called a straight set. From start to finish no breaks in between. This is the most common strength training method. And without a doubt, the most successful one. 

A cluster set is a type of set, where you take a straight set, and break it into smaller ‘mini-sets’ with short breaks intra-set rests in between these ‘mini-sets’. The same aforementioned ten-rep set could look like this: At first you do four reps, you rack the weight and rest for a little bit, then you do three more reps and rack the weight again, after a short rest you finish your set with the remaining three reps, totaling ten reps. After this you take a longer rest interval. 

Now this gives you a of couple really good advantages. Number one, you get to perform very high-quality reps, since you are less fatigued even during the last ‘mini-set’. And number two, you can lift either more weight doing the same amount of repetitions or you can do one or two repetitions more with the same weight. 

Usually you can lift 2-5% more weight using cluster-sets compared to straight sets, when reps are matched. Alternatively, you can perform one or two repetitions more with the same load.

What are the key components to programming cluster sets? 

First you must decide, do you want to lift more weight, or do you want to do more reps. Either option is fine, but I have a simple question to help you decide which way to go. What is my goal in training? Strength or hypertrophy? 

If the answer is strength, I keep the rep amount same, and aim to lift more load. If I’m aiming more towards hypertrophy (muscle building), I add a rep or two. If I want to go for more endurance, I go with more reps also. 

Simple enough? Strength -> More intensity. Hypertrophy -> More volume. 

Then there are two things that make a cluster-set. The length of the ‘mini-sets’ and the length of the intra-set rest interval. 

Lets take a new example: I want to go for more strength using five reps per set. Therefore, the goal is to add more load. 2-5% more than usual. Lets say my 5RM weight is 150 kg. So, I’m going to use 155 kg for this set. I will break up the five reps into five singles, this way I can focus on each rep like it’s a one rep max attempt. Programmed: 5x1. I don’t want the set to last for an eternity, so the intra-set rest between reps is going to be 20 seconds. Just enough for the nervous system to recover a bit, but not fully. After the fifth rep, I take a longer rest, just like after a straight set. 4-5 minutes rest in this case. 

Another example, my goal is now hypertrophy and I still want to use the same weight as in the previous example, 150 kg. Instead of adding load I aim to do one more rep each set. Since I’m doing more reps, I don’t want to make the set any longer. Therefore, I make the ‘mini-sets’ a bit longer. I will be doing three sets of doubles. Programmed 3x2. I could use the same intra-set rest interval of 20 seconds, but instead I will rest 30 seconds between ‘mini-sets’. After the third ‘mini-set’, I take a longer break of 4-5 minutes. 

I usually program cluster-sets in my programs like following: 

3 x (5 x 1), 20 sec (5 min) or 3 x (3 x 2), 30 sec (4 min) 

It's probably better to do longer 'mini-sets' for hypertrophy and singles or doubles for strength. Simply because you want to keep the set length somewhat reasonable. 

General guideline for the intra-set rest periods is between 10 to 45 seconds between 'mini-sets'. Longer rest periods for strength, shorter for hypertrophy. 

Which weights to pick for cluster-sets? 

I usually never start my cluster-sets with actual rep maxes. In the previously used example, I had a 5RM of 150 kg. Now, if I were to start a new mesocycle of training with those types of cluster-sets, I would most likely begin with 145 kg. Or even less! And build up the weight in the following weeks. First session is going to be a bit easier, but that’s alright, it’ll still be effective training. 

If you know some rep maxes in your main lifts and you decide to build your cluster training around that repetition range, I suggest you start with at least 5% less weight on the first set. Especially if it’s a completely novel type of set / rep set-up. Just to give yourself some time to get used to that set-up and allow room for progression for the future. 

You can also take advantage of rep max calculators and intensity charts to estimate the weight if you don’t know your rep maxes. But you need to know at least one. If you know your one rep max, simply check, how much weight you could approximately use for five reps or so. Then pick that weight, or preferably 5% lower, like mentioned previously.

 

Repetitions allowed on average in relation to 1 rep maximum. 

Hopefully you found this advice helpful, and now you have a better understanding of cluster training. If you want to test the cluster-set method in action, but don’t want to bother programming them yourself, check out my CookieCutter-program. 

It is a training platform I’ve created and the program itself has multiple uses of clusters. It is also a much more than a regular program, it will coach a little as well. Go check it out! 

Thank you! 

Sincerely, 

Mitja. 

Follow me on Instagram: mitja_lievonen 

My Website: www.mlstrengthperformance.com 

References: 

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. 

Haff GG, Hobbs RT, Haff EE, Sands WA, Pierce KC, and Stone MH. Cluster training: a novel method for introducing training program variation. Strength Cond J 30: 67-76, 2008