The Best Strength Training Method of All Time

The Cluster Training Bible

Cluster training is unbeatable for strength gains. But which type should you use? Here’s what you need to know.

Twenty-plus years ago I attended a Charles Poliquin seminar. I was 19 years old and competing in Olympic lifting. I was looking for ways to get as strong as possible. Charles was the man when it came to strength.

I mustered up the courage to approach him. I asked, “Mr. Poliquin, what’s the best training method to get stronger?”

“The best method to get stronger is clusters. You do one rep, rest for around 15-20 seconds, do another rep, rest 15-20 seconds, then do another rep. You do that until you get to five with a weight you’d normally only lift three times.”

The next week, I tried it on squats. The rest is history. I had my fastest squat strength gains, ever. I was hooked.

Years later I’d apply it to the bench press. It’s one of the main methods that allowed me to eventually reach a max of 445. I became a champion of clusters and have used them with many athletes. The results are always impressive.

The only problem? The traditional Poliquin approach didn’t always work well. Some athletes (the more advanced lifters) often couldn’t get five cluster reps with their three-rep max. Some would burn out. And some actually had to use less weight than their 3RM.

I started researching the subject and found different options that allowed all lifters to greatly benefit from the approach. We’ll get into those options, but first let’s talk about why clusters work.

Why Even Do Clusters?

If you want a more in-depth look at them, check out Question of Strength 60 where I share the details. If you’re already an expert on clusters, skip ahead, but here’s a quick refresher on the benefits:

You Recruit and Fatigue Fast-Twitch Muscle Fibers.

Recruitment is maximized when the load on the bar is at least 80-82 percent of your max strength. In a cluster set, all of your reps fall into that zone.

That means every rep is maximally effective at stimulating hypertrophy and increasing strength. You’re also able to do this with no “garbage volume” since all reps are maximally effective at recruiting the fast-twitch fibers.

You Develop the Capacity to Make the Fast-Twitch Fibers “Twitch” As Fast As Possible.

This is called a “high-firing rate” and it’s the real key to strength. The faster your fibers can fire (fire more frequently in a given unit of time) the more force you produce. This firing rate increases exponentially when the load is more than 85 percent of your max.

With clusters, every rep is in that zone too. So the more of these reps you have relative to your total number of reps, the better you are at programing your nervous system to make your fibers fire with a high rate. As a result, you get stronger.

You Build Muscle Mass.

Stimulating growth is, in large part, a matter of putting mechanical stress on the highest number of muscle fibers possible. First you must recruit these fibers, then every time you lengthen those fibers while they’re under load (eccentric/negative portion of the rep) you trigger the mechanisms that lead to growth. The heavier the weight, the greater the mechanical load on the fibers.

With maximal loading comes a lower number of reps per set, which means fewer occasions to impose the mechanical stress while the fibers are lengthening. But with a cluster set, you get more reps in a set while also maximizing load. That makes cluster training a powerful hypertrophy method.

You Desensitize the Golgi Tendon Organs (GTOs).

The GTOs are sensors in your tendons. They inhibit further force production when they sense that you’re already producing too much for your own structural integrity. They limit how much of your force potential you can produce.

Heavy lifting can, over time, desensitize the GTOs. This will allow you to use a greater percentage of your potential. Using a fairly high amount of heavy work – like you would during clusters – is an effective tool for desensitizing those sensors.

You Become More Comfortable with the Lift.

Clusters are great at getting you used to handling heavy weights. Nowhere is this more noticeable as with the walk-out in a squat or the unracking on the bench press. These actions are often done poorly with heavy weight.

As a result, a lot of heavy lifts are missed before you even attempt them. With a cluster set you “practice” those actions up to seven times per set with a near maximal weight. In virtually no time you can become a lot more stable with that phase of the lift.

You Get a Higher Quality of Heavy Work.

Because of the intra-set recovery period, your capacity to produce force is better maintained from rep to rep. This leads to better technique maintenance.

The 5 Types of Clusters

Now let’s look at a few solid ways to do them for maximal strength development. Other options exist that are better suited for hypertrophy, but that’s for another day.

1. The Poliquin Cluster

Coach Poliquin popularized clusters. His approach is the best known and most widely used, but he didn’t invent the cluster concept.

His cluster approach is solid for both strength and size gains in intermediate lifters. With advanced lifters it’s a great way to build muscle, but might not be the best option for maximizing strength gains.


  • Number of singles in a set: 5
  • Rest between singles in a cluster: 15-20 seconds
  • Load: 87-90% or your 3RM
  • Number of cluster sets: 3-5
  • Rest between sets: 3-4 minutes

When you’re very strong (or have a high ratio of fast-twitch fibers) the 15-20 seconds of rest can be insufficient for taking advantage of the potentiation effect. The sub-optimal rest decreases performance capacity enough to mask the increase in performance that’d come from the neural activation from the heavy rep.

Some people might need at least 30 seconds of rest to get the full benefits of clusters for strength gains. However, if your goal is to get both size and strength as an advanced lifter, Poliquin clusters are super solid.

I also find the Poliquin cluster to be superior for women since they don’t seem to require the same amount of rest to recover.

2. The Original: Carl Miller Clusters

Carl Miller coached weightlifting for over 50 years, including at the highest level (1976 Olympic games for example). He was the first one to use clusters as an official method. Miller used two main types of clusters. An extensive (more volume) method and an intensive (higher load) method.

The weight used depended on the type of movement selected. For example, on technically complex movements like the snatch or clean & jerk, a lower percentage would be used compared to the squat, press, or deadlift.

Guidelines (Extensive)

  • Number of singles in a set: 5-7
  • Rest between singles in a cluster: 30-45 seconds
  • Load: 85-92% for strength movements, 80-85% for Olympic lifts
  • Number of cluster sets: 3-5
  • Rest between sets: 2-3 minutes

Note: The rest between singles in a cluster could be increased in the last two sets if 4-5 sets were used.

Guidelines (Intensive)

  • Number of singles in a set: 2-3
  • Rest between singles in a cluster: 45-60 seconds
  • Load: 87-95% for all movements (clean & jerk could be as low as 82%)
  • Number of cluster sets: 3-4
  • Rest between sets: 2-3 minutes

These types of clusters are more appropriate for very strong athletes or those with a high ratio of fast-twitch fibers. Very strong lifters will need the longer rest between reps to take advantage of the potentiation effect of clusters. Miller clusters are a pure strength method. They will result in less muscle growth than the Poliquin cluster.

3. The Eccentric Overload Cluster

This method was born from my love of weight releasers as a training tool. Weight releasers are hooks on which you can add weight. Those hooks are attached to the bar, overloading the eccentric (lowering) phase of the lift. When you hit the bottom, they’re released from the bar, reducing the weight you need to lift.

Here are two examples of lifts using weight releasers. The first is used to overload the eccentric; the second is used to create an isometric overload.

Because of the nature of the weight releasers, you must use a cluster approach. You have to reset the releasers on the bar before every rep. This takes at least 15 seconds (unless you have two partners). So, it makes sense to always rely on a cluster setup whenever using weight releasers.

Here’s an example on the bench press:

You can use the same work-to-rest ratio as either the Poliquin or Miller clusters. The load would obviously vary depending on the approach.

Eccentric Overload (Poliquin) Guidelines

  • Number of singles in a set: 5
  • Rest between singles in a cluster: 15-20 seconds
  • Load: 75-80% on the bar, total of 100% on the eccentric (extra 20-25% on the releasers)
  • Number of cluster sets: 2-4
  • Rest between sets: 3-4 minutes

Eccentric Overload (Miller Extensive) Guidelines

  • Number of singles in a set: 5-7
  • Rest between singles in a cluster: 30-45 seconds
  • Load: 75-80% on the bar, 100-105% on the eccentric (extra 20-30% on the releasers)
  • Number of cluster sets: 2-4
  • Rest between sets: 3-4 minutes

Eccentric Overload (Miller Intensive) Guidelines

  • Number of singles in a set: 2-3
  • Rest between singles in a cluster: 45-60 seconds
  • Load: 80-85% on the bar, 105-115% on the eccentric (25-35% on the releasers)
  • Number of cluster sets: 2-4
  • Rest between sets: 3-4 minutes

Note that the number of sets is decreased because of the demands of the eccentric accentuation.

What are the benefits of this eccentric accentuation? An eccentric overload is the method that leads to the greatest increase in the muscle fiber’s firing rate – the real key to strength production.

In an eccentric or lowering action you preferentially recruit the fast-twitch fibers. As you need to produce more and more force, you can’t rely on bringing more fibers into play like you would during a concentric (lifting) action because the stronger fast-twitch fibers are already working. The only way to produce more force is to make those fast-twitch fibers fire faster and more often.

By doing this, over time you can improve your neuromuscular system to produce a higher firing rate, which will dramatically increase force production. Another benefit? The stronger a muscle is eccentrically compared to its concentric strength, the lower the risk of injury.

4. The Mentzer Cluster

Mike Mentzer and his brother Ray are better known for Heavy Duty Training. They were insanely strong bodybuilders, and this cluster variation was one of the tools they came up with to build their strength. This approach could be seen as the advanced version of either the Poliquin or the Miller clusters.

You start with a load that’s 95-97 percent of your 1RM (the most weight you can lift with solid form) and you do 3 cluster reps. You then reduce the load by 10 percent (85-87 percent of 1RM) and get an extra 2-3 reps, still in cluster format.

A set could look something like this:

  • Rep 1: 97%
  • Rest 15 seconds
  • Rep 2: 97%
  • Rest 15 seconds
  • Rep 3: 97%
  • Rest 15 seconds
  • Rep 4: 87%
  • Rest 15 seconds
  • Rep 5: 87%

You can use the Mentzer approach with either the Poliquin or the Miller work to rest ratios:

Mentzer/Poliquin Cluster (Intermediate) Guidelines

  • Number of singles in a set: 5-6
  • Rest between singles in a cluster: 15-20 seconds
  • Load: 95-97% or 85-87%
  • Number of cluster sets: 2-3
  • Rest between sets: 3-4 minutes

Mentzer/Miller Extensive (Advanced) Guidelines

  • Number of singles in a set: 5-7
  • Rest between singles in a cluster: 30-45 seconds
  • Load: 95-97% or 85-87%
  • Number of cluster sets: 2-3
  • Rest between sets: 3-4 minutes

5. The Giant Cluster

I popularized this method twelve years ago here on T Nation and it was used by World’s Strongest Man, Martins Licis, for his deadlift. It’s different from the previous methods in that it’s a submaximal method, and the goal is to develop “strength-skill” as well as resilience under high loads.

You essentially set up a certain time frame: 12, 15, or 20 minutes in most cases. Then pick an intensity zone: 80, 85, or 90 percent, and choose a number of reps per set: 1, 2, or 3.

You then do as many quality sets as you can in the prescribed time zone. The number of sets you can get will depend on your level of conditioning, strength, and muscle fiber ratio.

Here are the parameters for the three intensity zones:

Guidelines – 80% Zone

  • Duration: 20 minutes
  • Reps per set: 3
  • Target number of sets: 12-15

Guidelines – 85% Zone

  • Duration: 15 minutes
  • Reps per set: 2
  • Target number of sets: 9-12

Guidelines – 90% Zone

  • Duration: 12 minutes
  • Reps per set: 1
  • Target number of sets: 7-10

The progression model is to select an intensity zone. Once you can reach the top of the sets’ range, you increase the weight.

So, Which Approach Should You Use?

You have three main categories of clusters (four with the giant cluster):

  1. The Poliquin work-to-rest ratio (15-20 seconds of rest)
  2. The Miller extensive work-to-rest ratio (30-45 seconds of rest)
  3. The Miller intensive work-to-rest ratio (45-60 seconds of rest)

All of these cluster approaches will be effective at increasing strength rapidly. However, the stronger you are, the more you should go with the Miller work-to-rest ratios. On the bigger lifts – like squats, front squats, deadlifts, and the Olympic lifts – the Miller ratios might also work better.

The Poliquin work-to-rest ratio will give you a bit more muscle growth stimulus. This could be an interesting tool for athletes who need to maintain a high level of force production with short rests. I’m thinking CrossFit athletes and MMA fighters.

Then you can select between three main methods for each of the work-to-rest ratio options:

  1. Normal sets
  2. Mentzer cluster
  3. Accentuated eccentrics

These are in order when it comes to the importance of the strength stimulus, but also on neurological and physiological demands.

The accentuated eccentric clusters provide a stronger stimulus than the normal sets, but they cost a lot more and will require a lot more recovery time. As such, these more demanding options should only be used by people with a background in high-level strength work. And the volume must be kept lower.

The giant cluster is a different animal and is a lower-impact approach. Its main benefit is teaching you to be comfortable and efficient under heavy loading. It’s great to reinforce optimal lifting technique as well as intra and intermuscular coordination. Of all the cluster methods presented, it’s the one you can use for the longest and that’s safely doable for most people.

If you want rapid strength gains, clusters are definitely worth considering. I started using them over 20 years ago and haven’t stopped. It’s something that has stood the test of time and been shown to work for pretty much everybody. Give it a shot if you’re ready to gain strength fast.