Using intra-set rest periods or "clusters" is hardly a new concept. In fact, Olympic lifters and even bodybuilders use clusters regularly, some without even knowing it.
Put simply, you add small bouts of rest (10-20 seconds) in between reps to provide recovery and avoid movement deterioration, which would normally occur during a straight set with appreciable loading.
In the book "Supertraining," cluster training is categorized two ways:
- Extensive clustering: 4-6 reps with your 4-6RM (reps max), 10 seconds rest intervals between each cluster of reps.
- Intensive clustering: 4-6 reps of only 1 rep between 75-90% of 1RM, about 20 seconds rest between reps.
There's a place for both extensive and intensive clustering, but for purposes of hypertrophy (size gains) where the intent is longer time under tension, extensive clustering fits the bill and can be used with several exercises where you'd normally experience high neural fatigue. Here's one example:
The Fat Grip Pull-Up
This is a great variation for cluster training. Even for pull-up ninjas, using a fat-grip can drastically cut down on the volume they can handle per set. Using extensive clustering works well, allowing you to almost bypass local muscle fatigue. With this variation, the pump you'll experience in the biceps, forearms, and even the latissimus will be surprising.
Here's how it looks:
- Do 3 sets of 5 reps
- Rest 10 seconds
- Do 3 reps
- Rest 10 seconds
- Do 2 reps
- Rest 2:30 before starting the next set.
With this variation, for me, the 5/3/2 rep scheme fit my ability and worked with the total volume I was looking for out of this movement (30 total reps).
Of course, you're only limited by your imagination, so you could certainly get creative and use cluster sets that align with your ability in terms of movement selection, volume, and composition of your sets.
- Choose a compound movement like a squat, bench press, pull-up, or dip with a load you can perform 5 solid reps with (for most, around 80-85% of 1RM).
- Perform sets that are submaximal, around 2-3 reps shy of failure, that will keep you away from complete movement deterioration even as the sets progress.
- Our goal is hypertrophy so total volume should be between 25-30 total reps.
- Weighted Wide-Grip Pull-Up: 3 x 5/3/2 (10 seconds rest). Rest 2:30
- Front Squat: 4 x 2/2/2 (15 seconds) at 80%. Rest 3:00
- Bench Press: 4 x 2/2/2 (15 seconds) at 80%. Rest 3:00
- Weighted Bar Dip: 3 x 4/3/3 (10 seconds). Rest 2:30
- Back Squat: 4 x 3/2/1 (20 seconds) at 85%. Rest 3:00
You'll also experience gains in maximal strength by using cluster sets, so don't underestimate the value of this work in terms of strength development.
Overall, using clusters is another method to take your game to the next level. Like anything though, you'll begin to accommodate if you use cluster sets too frequently, so strategically add them into your programming one movement a time.