Cluster sets are capable of giving you significant gains in size and strength in a short period of time.
When programming for my athletes in the Swole Town Program, I'm constantly looking for ways to make my training cycles as effective as possible.
I don't want guys (or girls) following my program in the gym wasting time with 20 different Bicep curl variations.
I want them to be big, strong and functional beasts. I can't have it any other way.
If you're interested in getting stronger, this will be a great read for you.
At the end I'll give you a full sample training day with cluster sets.
*Note: Heavy Cluster training is on the advanced side. Don't attempt this method if you're a beginner.
The "More is Better" Trap
Most people in the gym believe that more is better.
Work harder, spend more time, do more reps, and your results will improve, right? Not so fast..
Your body does not have endless energy to expend.
Training requires a lot of energy, and what people forget is that recovering from training also requires a massive amount of energy.
No matter what you do, there is only so much you can recover from.
If you cannot recover, your body does not adapt to the training.
That means you work hard and get little results, especially if you're trying to get stronger and/or build muscle.

How Does The Body Get Stronger?
If you're stronger today than you were a month ago.. Why is that?
What caused you to be able to exert more force?
Is it simply that working out builds muscle, and more muscle = more strength?
While it's true that more muscle mass will generally correlate with greater strength, there are plenty of examples of people who you wouldn't even know worked out who can lift superhuman amounts of weight.
My brother-in-law looks like a regular 170lb guy, and has more than once casually stepped into my gym and pressed 275lbs over his head, while I stand at a solid 240lbs and cannot perform that on my best day.
Is it not a fascinating question?
How can someone with less muscle exert more force than someone with considerably more? The answer lies in the nervous system.
The Nervous System Controls Strength

When you lift, you are not using all of the muscle available.
Your nervous system is much smarter than you, and its job is to protect the integrity of the structures within its control (among other things).
Trying to lift something very heavy could hurt you, and to protect you from injury, the nervous system will not allow you to recruit all of the muscle fibers at once.
An untrained person will be able to recruit only about 40-50% of the available muscle fibers at once.
A highly trained strength athlete can recruit well over 90%, and the strong guy in the gym is probably in the 70-80% category.
So How do you train the nervous system to allow you to recruit more muscle fibers and get stronger?
Strength is a Skill
I think it's most useful to think of strength as a skill.
You have to view training as an opportunity to "teach" the body how to be stronger.
With that in mind, it becomes obvious that the way you set up your training is extremely important when your goal is to become stronger.
You cannot just go do your usual 3 sets of 10 on the bench press and expect to get dramatic results.
Unless you're a new lifter, this simply will not work for very long.
If you've been training that way for a long time, your body has adapted already and has no need to take any further action.
Cluster Sets
Cluster sets are basically heavy singles performed on short rest periods, generally around 20 seconds long.
So, you hit one heavy rep, rest 20 seconds, and repeat for the prescribed number of reps.
The benefit here is that you're lifting very heavy weight relative to your max.
If you're able to get 5 reps normally with 225lbs, you can use clusters to get 6 or more reps in one set by spacing the reps out with very short rest periods.
How Cluster Sets Make You Stronger

When lifting loads at about 85% or higher relative to your max, you're recruiting the maximum amount of muscle fibers that you're capable of.
With lighter loads/higher reps, this is not the case until the end of the set when you're fatigued.
Recruit the Highest Threshold Motor Units/Muscle Fibers
Heavy loads are forcing the nervous system to call upon the highest threshold muscle fibers.
The ones most capable of producing force.
As the load increases (relative to what you're capable of), these high-power motor units must fire at a faster rate to keep up.
Thus, you're teaching your nervous system to fire those high-impact muscle fibers faster by repetitively hitting them with heavy loads.
This alone will make you stronger. Every rep you hit in a cluster set is an impactful rep, from the first to the last.

Turn off The Governor
Like a governor on a vehicle that slows it down when it reaches a certain speed, your muscles contain organs called Golgi Tendon Organs (GTO's) that are constantly monitoring tension.
The GTO's will basically turn muscle fibers off when tension gets too high, in an effort to protect the structure.
The repetition of heavy loads can desensitize the nervous system, relaxing the GTO's and allowing more force to be produced. Again, every rep in a cluster set is intense, and we're training the nervous system to allow us to produce more force.
You Become Better at the Movement
When repeating heavy lifts on 20 seconds of rest, you don't have time to overthink anything.
You simply grab the bar and perform the lift.
This type of training really forces you to be in the moment.
The heavy repetitions will make you more comfortable with the lift, and you will naturally get better at it.
It also alleviates some of the fear of moving heavy weight, as you're doing it repeatedly.
Sample Training Session Using Cluster Sets
The training session below is directly from the Swole Town training cycle called "Intensity."
Keep in mind that when using high intensity methods like these, it is imperative that you keep the overall volume low. (volume = the total amount of reps/sets, or "work" that you're doing.)
You absolutely have to prioritize recovery, as you're pushing the body/nervous system very hard with the heavy repetitions.
Too much volume and accessory work and you'll burn yourself out.
Cluster Set Training Sample: Bench Press/Back

You want to get a solid warm up in, and I prefer a circuit style warm up here as it allows me to sneak in a little low-intensity volume, build work capacity, and prepare for the session.
The weight should be very light, this should not be a struggle.
A.) Prep Circuit:
Perform 2-3 sets, moving continuously with little rest.
Movement | Reps |
DB Incline Bench Press | 20 |
DB Bent Over Row | 20 |
Band Triceps Pressdown | 20 |
Ab Crunches | 20 |
B.) Cluster Sets: Bench Press
Take a few warm-up sets of 2-3 reps to build up to about 87-90% of your max on the bench press.
You'll do 5 total reps per set, hitting one rep every 20 seconds. After 5 reps, rest 4:00 and repeat.
After 2 sets, assess how you feel and hit a 3rd set if you're feeling good about it. If you've never done these, stop at 2 sets.
Movement | Sets | Reps | Rest b/w sets |
Bench Press | 2-3 | 5 reps at 87-90% of max 20 seconds between reps | 4:00 |
C.) Close Grip Floor Press
We're choosing a movement complimentary to the bench press to get in some additional heavy volume. We'll hit 3 heavy sets of 5. Heavy meaning you're not sure if you'd have gotten another rep or two.
Movement | Sets | Reps | Rest b/w sets |
Close Grip Floor Press | 3 | 5 | 3:00 |
D.) Bench Supported DB Row
Perform on an incline bench. These are to be performed as drop-sets, hitting 8-10 reps, then dropping to lighter dumbbells to get up to 20 reps per set, for 2 total sets.
Movement | Sets | Reps | Rest b/w Sets |
Supported DB Row | 2 | 20 | 3:00 |
E.) Decline DB Pullover
Same as the last block, perform 2 drop-sets, aiming for 8-10 reps, then dropping down to a lighter dumbbell and getting up to 20 total reps.
Movement | Sets | Reps | Rest b/w Sets |
Decline DB Pullover | 2 | 20 | 3:00 |
F.) Plank to Side Plank - 2:00
30 second front plank, 30 second side plank, 30 seconds back to front, then 30 seconds other side for 2 total minutes. These are used frequently for endurance throughout the core and to enhance core bracing.
Full Workout Table
I'll put this session in one table if you'd like to try it out, feel free to screenshot.
Movement | Sets | Reps | Rest b/w Sets |
Warm up Circuit | 3 | 20 | 0 |
*Bench Press (Cluster) | 2-3 | 5 (cluster reps) 20 sec b/w reps | 4:00 |
Close Grip Floor Press | 3 | 5 | 3:00 |
Bench Supported DB Rows | 2 | 20 (dropset) | 3:00 |
DB Decline Pullover | 2 | 20 (dropset) | 3:00 |
Plank to Side Plank | 1 | 2:00 hold | n/a |
Final Notes on Cluster Sets
As you can see, the overall volume in this session is pretty low. 9 total sets of lifting (warm up sets don't count).
If we start throwing in all kinds of curls, triceps extensions, etc. we'll be forcing the body to try and recover from more than it will likely be able to.
Recovery is everything when you're training for strength and size.
If you're going to try out training with cluster sets, devote a training block of 4-6 weeks with it.
Give your body some time to adapt and you'll likely see some nice gains in strength and probably some new muscle to go along with it.
If you'd like to have your workouts programmed for you so you can hit the gym with a solid plan, check out Swole Town, available only the world's best training app, TrainHeroic.
Thanks for reading! Any questions? Feel free to reach out.
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