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5/3/1 Variations: FSL, BBB, Jokers and 5s PRO Explained
Spend a little time with 5/3/1 and you quickly hit a wall of abbreviations:
FSL. SSL. BBB. BBS. 5s PRO. Jokers. Leader. Anchor.
At first glance it looks like a collection of entirely different programs.
In reality, many of these terms answer different questions within the same piece of programming.
That is the key to understanding them.
BBB and 5s PRO, for instance, are not direct competitors. One describes supplemental work; the other changes the main work.
A useful mental model is therefore to break 5/3/1 into several layers.
Important: these three layers are a teaching device, not an official Wendler taxonomy.
The model: three questions instead of twelve abbreviations
| Layer | Question | Examples |
|---|---|---|
| 1 · Supplemental work | What do I do in addition to the main sets? | FSL, SSL, BBB, BBS |
| 2 · Main work | How do I perform the main sets? | PR set, 5s PRO |
| 3 · Program frame | How do training phases alternate? | Leader, Anchor |
On top of that come elements like Joker sets or the 7th Week Protocol, which take on additional roles depending on the program.
With this model, a chaos of abbreviations turns into a series of relatively simple decisions.
The foundation first: main work
Every variation builds on the same underlying idea:
The main lifts are driven by a Training Max.
Classic 5/3/1 uses the familiar wave:
| Week | Main sets |
|---|---|
| 1 | 65 / 75 / 85 % |
| 2 | 70 / 80 / 90 % |
| 3 | 75 / 85 / 95 % |
If this structure and the function of the Training Max are new to you, start there first.
→ Jim Wendler’s 5/3/1 explained
The variations only make sense once it is clear which part of the base system they change.
Layer 1: supplemental work
Additional work can follow the main work.
This is where terms like these live:
- FSL
- SSL
- BBB
- BBS
- Widowmaker
They all answer roughly the same question:
How do I accumulate additional work on the main movements?
Which is why you do not normally pick several of them and stack them on top of each other.
FSL — First Set Last
The name already describes the idea.
After the main work you go back to the weight of your first working set.
With the classic wave that means:
| Week | FSL weight |
|---|---|
| 1 | 65 % TM |
| 2 | 70 % TM |
| 3 | 75 % TM |
One common scheme is:
5 × 5 FSL
That gets you additional reps at a weight heavy enough for technically relevant work, but clearly below the heaviest set of the day.
Wendler himself describes 5×5 FSL as high-quality work that is easy to recover from.
Which is exactly what makes FSL such an accessible supplemental building block.
SSL — Second Set Last
SSL follows the same logic but uses the weight of the second main set.
That raises the demand considerably.
From:
65 / 75 / 85
you would get supplemental work at 75 % TM, for instance.
So SSL is not simply “FSL plus a bit more weight”.
Across several sets, that difference changes the fatigue noticeably.
If you can already use FSL productively, you do not automatically need SSL. Heavier is only better when the heavier weight fits the rest of the programming.
BBB — Boring But Big
BBB shifts the emphasis in a different direction.
Instead of sets of five, what typically follows is:
5 × 10
with a considerably lighter weight.
That produces high rep counts and a lot of supplemental volume.
Wendler has published several BBB programs, so you should never look at a single percentage without its program context.
As a basic starting point, 50 % of the Training Max is very common.
→ Boring But Big: getting the 5×10 right
BBS — Boring But Strong
Boring But Strong also uses a lot of total work, but distributes it differently.
Instead of five sets of ten, it uses many shorter sets.
That gives you high total volume without producing the same local fatigue as a set of ten.
It is a good example of why the total rep count alone is not enough to judge a session.
50 reps as 5×10 feel different from 50 reps as 10×5.
Widowmaker
With the Widowmaker, volume is not spread across many sets.
Instead a single very long, very hard set takes centre stage.
That shifts the demand again.
So the key insight is not that FSL, BBB or the Widowmaker are differently “hard”.
They organise supplemental work differently.
And a structure like that needs to fit the rest of the program.
Layer 2: how does the main work run?
Now the question changes.
BBB or FSL do not necessarily tell you how to perform your last main set.
There are other concepts for that.
PR sets
In classic 5/3/1, the main work ends with a plus set:
5+
3+
1+
You complete at least the prescribed number and then continue with further technically clean reps.
The goal is not absolute muscular failure.
But the set can deliver a rep PR and therefore show how your performance is developing.
5s PRO
5s PRO changes the main work.
Instead of:
- 5 / 5 / 5+
- 3 / 3 / 3+
- 5 / 3 / 1+
the main sets are performed for five controlled reps.
The plus is dropped.
That lowers the variable demand of the main work.
Which can be exactly right when a lot of supplemental work is planned elsewhere.
The principle behind it matters more than the abbreviation:
If you add more training in one place, you often have to take something back in another.
5s PRO creates that room.
PR set or 5s PRO?
The wrong question would be:
Which of these is better?
The better question is:
What is this training phase supposed to achieve?
A PR set gives you more opportunity to show performance directly and collect rep PRs.
5s PRO controls the demand more tightly and can therefore leave more resources for supplemental work.
Both can be sensible.
Just not necessarily at the same time and in the same program.
And where do Joker sets fit in?
Joker sets are additional heavier sets above the regular main work.
They became widely known through Beyond 5/3/1, and in later programs they are not treated as an automatic requirement.
That matters.
A Joker set does not mean:
The normal plan was too easy today, so I have to keep adding weight.
It is a program-specific tool for additional intensity.
If you routinely add Joker sets on top of PR sets, heavy supplemental work and lots of assistance, you change the demand of the whole program.
So the word “Joker” should not be read as a licence for unplanned max training.
Layer 3: Leader and Anchor
With 5/3/1 Forever, the perspective widens.
Instead of only asking what happens after today’s main set, you plan how different training phases follow one another.
Wendler uses the terms Leader and Anchor for this, among others.
What is a Leader?
A Leader typically puts more weight on building work.
Depending on the program, that might mean:
- controlled main work
- more extensive supplemental work
- less aggressive PR work
- program-specific assistance
BBB is a good example of something that can fit into that kind of building context.
The purpose is not to demonstrate maximum performance every week.
You are building work that is meant to be used later.
What is an Anchor?
In the Anchor the emphasis shifts.
Supplemental work can be reduced and more intense elements can get more room again.
Depending on the specific program, that might include PR sets or other more intense work.
But an Anchor is not simply:
Leader + even more weight.
It changes how the demand is distributed.
That is the core of the system.
Why Leader and Anchor exist at all
Suppose you try to do all of this at once:
- run BBB 5×10 heavy
- push every last main set to the limit
- add Joker sets
- do plenty of assistance
- run hard conditioning
Each individual item can be sensible.
The problem comes from the sum.
Wendler criticises exactly this kind of programming: several demanding elements stacked together at the same time, even though time and recovery are limited.
Leader and Anchor do not solve that with a complicated formula.
They distribute priorities across time.
So the key rule is not “one variation per layer”
The three-layer model is useful.
But it should not become a new rigid rule.
5/3/1 Forever contains many complete programs whose individual parts are already balanced against each other.
So the better rule is:
Pick a complete program and understand what job its building blocks do.
Not:
I like BBB. FSL sounds good too. Jokers are fun. And 5s PRO is supposed to save recovery. So I’ll take all of it.
That is not an individualised program.
It is a collection of features.
FSL or BBB?
This is one of the more meaningful direct comparisons.
FSL 5×5
- fewer reps per set
- heavier weight
- very good for additional technically high-quality work
- tends to be easier to recover from
BBB 5×10
- more reps per set
- lighter weight
- higher local volume
- tends towards a stronger hypertrophy emphasis
- higher demands on recovery
Wendler himself points out that BBB often delivers somewhat more muscle growth, while FSL 5×5 is easier to recover from.
That does not make either of them better in general.
It only answers the question:
Which stimulus fits your training better right now?
Classic 5/3/1 or Forever?
Here too there is no reason to automatically treat the more complicated system as superior.
If you are new to 5/3/1, the classic base system is valuable because you first learn:
- how your Training Max behaves
- how hard the individual weeks really are
- how to read PR sets
- how you respond to slow progression
Only after that do terms like Leader, Anchor, 5s PRO and various supplemental profiles become genuinely useful.
It is no accident that 5/3/1 Forever assumes knowledge of the base system.
A practical orientation
| Situation | Sensible starting point |
|---|---|
| completely new to 5/3/1 | understand the base system first |
| additional, easily controlled work | FSL |
| more supplemental volume / muscle growth | BBB |
| a lot of supplemental work planned | control the main work more tightly, e.g. program-specific 5s PRO |
| more intense phase | a suitable Anchor program |
| more weight feels exceptionally good today | do not automatically add Jokers — check the program |
| you want BBB + Jokers + PR sets + lots of assistance at once | probably reduce your priorities |
The table does not replace a specific template.
It only shows which question each building block answers.
How hitPR maps the variations
hitPR includes several 5/3/1-based plans with different emphases.
Wave periodisation (strength)
Additional 5×5 work after the main work.
Conceptually that sits closer to FSL-style supplemental work.
Wave periodisation (volume)
5×10 after the main work.
That puts the emphasis considerably closer to BBB.
Wave periodisation (realisation)
Supplemental volume is pulled back in favour of a more intense phase, or a test.
That makes the same underlying idea visible that sits behind separating building and realisation phases:
Not every training quality gets maximised at the same time.
Conclusion
The many 5/3/1 terms get considerably simpler once you ask which part of the training they actually change.
As a mental model:
- Supplemental work: FSL, SSL, BBB, BBS …
- Main work: PR sets, 5s PRO …
- the larger program frame: Leader, Anchor …
Joker sets and other tools join in depending on the specific program.
The key takeaways:
- FSL and BBB are different kinds of additional work.
- 5s PRO changes the main work and can free up recovery for other training.
- Joker sets are not mandatory and are no substitute for sensible progression.
- Leader and Anchor distribute training priorities across longer stretches of time.
- 5/3/1 Forever is not merely a list of freely combinable templates.
- Heavier, longer and more all at once is not automatically better.
Which is probably the most important 5/3/1 rule of all:
A good program does not consist of using as many good training ideas as possible at the same time. It consists of using the right ideas at the right time.
Sources
- Jim Wendler: 5/3/1, 2nd Edition.
- Jim Wendler: Beyond 5/3/1.
- Jim Wendler: 5/3/1 Forever.
- Jim Wendler: 5/3/1 for Beginners
- Jim Wendler: 5x5 First Set Last vs Boring But Big
- The Fitness Wiki: 5/3/1 Primer
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