Cluster sets are one of the most powerful training methods for intermediate and advanced lifters. A typical set looks like this:

  1. Load the barbell (or machine) to 90% of your maximum, a weight you could normally lift 3 times.
  2. Do one rep and rack the bar. Rest 10 seconds.
  3. Do another rep and rack the bar. Rest for 10 seconds.
  4. Continue in this manner until you reach the maximum number of reps you can do, which should be between 4 and 6 reps.

Regular clusters shine when it comes to muscle damage and mechanical stress, but they neglect the other two hypertrophy pathways: the release of local growth factors and the mTOR pathway. So if we want to make clusters even more effective, we should find a way to include these two elements. Here's how.

A Max-Growth Cluster Set

Starting Weight: 225 pounds

All reps are done with a 4-second lowering or eccentric phase.

  • 1 rep, rest 10 seconds
  • 1 rep, rest 10 seconds
  • 1 rep, rest 10 seconds
  • 1 rep, rest 10 seconds
  • 1 rep, no rest

Immediately drop to 150 pounds. Do 8-10 reps with constant tension – controlled repetition tempo, no lockout at the top.

That final drop set is what really ramps up the muscle growth potential of cluster sets.

What Weight to Use

The load should be 85% of 1RM or more. At first you might have to use a bit less weight to get used to the intensity, but under no circumstance should you use less than 80%. Work up to being able to handle 85-90% for all work sets.

How Long to Rest

Max-growth clusters end with constant tension reps which will lead to an intense accumulation of metabolites and hinder force production until properly recovered. Using longer rest intervals in this instance is mandatory. You might lose some performance between sets, but you should stick to the same starting weight. If necessary, drop one cluster rep (maybe go from 6 to 5, or 5 to 4). That's fine as long as you stay in the 4-6 range with the correct load.

How Many Sets to Do

Unlike classic cluster sets, which require about 5 sets, you only need 3 sets with max-growth clusters.

Exercises

This method can work with any exercise. People might assume it only works with big, compound movements, but it works with anything, even machine curls.