5/3/1 Boring But Big: Getting the 5×10 Right

Boring But Big has one of the simplest recipes in the entire 5/3/1 system:

After the main work you do five sets of ten reps of a main lift.

Formally, there is barely more to it than that.

In practice, though, exactly one question decides whether BBB produces productive volume or simply a great deal of fatigue:

How heavy do you make that 5×10?

Because 50 reps at 50 % of your Training Max is an entirely different session from 50 reps at 70 %.

What is Boring But Big?

BBB is supplemental work within the 5/3/1 system.

After the main work itself comes a large volume block.

A classic bench day might look like this:

The name is fairly accurate.

Five sets.

Ten reps.

The same basic movement, over and over.

No complicated exercise rotation and no special intensity system.

Which is exactly why BBB is easy to understand — and easy to underestimate.

50 reps change the whole session

With a light weight, 5×10 sounds harmless at first.

But fifty reps of a squat, a deadlift or a press produce considerably more total work than a few extra heavy fives.

The goal is therefore not to turn every set into a battle.

The challenge builds cumulatively.

Set 1 can feel very easy.

So can set 2.

What matters is whether sets 4 and 5 still look clean.

Which is exactly why choosing the weight matters more than how the first ten reps felt.

What percentage should you start BBB with?

For classic BBB, 50 % of your Training Max is a very sensible starting point.

Wendler has repeatedly used that figure as a baseline himself.

Which means:

Squat TM: 140 kg

BBB at 50 %:

70 kg × 10 × 5

If you have barely trained high-volume compound work before, do not underestimate how those 50 reps add up across several weeks.

The right start is therefore not the heaviest weight you can somehow drag through five sets.

The right start is a weight that lets you complete the prescribed work repeatedly and recoverably.

Are 60 or 70 % also BBB?

Yes — but context matters here.

Wendler has published several BBB variations.

One well-known example is the Boring But Big 3 Month Challenge.

There the weight climbs across three months:

Anyone who sees only that table might conclude:

So 70 % is just a harder version of BBB.

That misses the most important part of the programming.

In this challenge the final 5/3/1 sets are not pushed for extra reps. You complete only the prescribed reps and save your recovery for the increasingly heavy 5×10 volume.

It is a good example of why individual percentages mean little if you ignore the rest of the program.

70 % BBB plus a maximal AMRAP plus lots of assistance is not the same program.

Why 50 % is the better entry point for most people

The stimulus in BBB does not come from every single rep being heavy.

It comes from the combination of:

a main lift + 50 reps + repeated training weeks.

At 50 % TM you normally have enough headroom for:

• clean technique
• controlled rest periods
• consistent rep quality
• progress across several weeks
• reasonable recovery

If instead you try to set the BBB weight as high as possible in your first cycle, supplemental work quickly becomes a second main workout.

At that point BBB competes with the work it is supposed to follow.

How do you know the weight is right?

There is no magic velocity threshold.

But a few questions help in practice.

Are all five sets complete?

That sounds obvious.

If a session that prescribes 5×10 regularly turns into

10 / 10 / 10 / 8 / 6

something is off.

Either the weight is too high, the rest periods too short, or the overall programming too aggressive.

Does technique stay stable?

A slower tenth rep in the fifth set is no surprise.

But if the movement increasingly turns into a different exercise, it is no longer quality volume.

Do you recover by your next relevant session?

This is the commonly overlooked test.

A workout can feel successful and still have been too much.

If your following session regularly suffers, the training volume was possibly higher than you can recover from.

So the question is not only:

“Did I complete 5×10?”

but also:

“What did that 5×10 cost me before the next session?”

You spot the right BBB weight in set 5, not set 1

The first ten reps tell you very little.

At a sensible BBB weight they are supposed to be manageable.

You do not need to feel, after set 1, that you have just trained unusually hard.

The load builds through the total work.

Which makes this a poor way to decide:

Set 1 was easy, so next time I’ll add a lot of weight.

More informative are:

• set 4
• set 5
• technique
• recovery after the session
• performance the following week

BBB is volume training.

You do not judge volume by the first ten reps.

Same lift or a different main movement?

BBB has been programmed in several variations.

The simplest version is:

Main work and BBB with the same lift.

For example:

bench press main work → bench press 5×10

That has an obvious advantage: you accumulate a great deal of work on exactly the same movement.

It can be correspondingly fatiguing, though, especially on squats and deadlifts.

Other BBB programs distribute main and supplemental work differently.

The main work for one lift might be combined with 5×10 of a different main movement, for instance.

So the important question is less which variation counts as “real BBB”.

More important is:

Which specific BBB program are you running?

An individual building block should not be pulled out of a complete template and combined with arbitrary other parts.

BBB and FSL solve a similar problem differently

Both BBB and FSL give you additional reps of the main movements after the main work.

But the nature of those reps differs.

FSL 5×5

Fewer reps per set, heavier weight.

That suits high-quality additional work well and is often easier to recover from.

BBB 5×10

More reps per set, lighter weight, and considerably more local fatigue.

Wendler himself describes BBB as tending more towards muscle growth, while 5×5 FSL is easier to recover from.

That does not mean:

FSL = strength and BBB = hypertrophy.

Both can support strength and muscle growth.

The difference lies more in how the stimulus is created and what it costs in recovery.

Assistance: BBB does not need a second bodybuilding session behind it

This is probably where the most common mistake happens.

After:

• main work
• 5×10 of a main lift

a session still feels “incomplete” to some people.

So along come:

Leg press.

Lunges.

Leg extensions.

Leg curls.

Calves.

Maybe a finisher too.

The problem is not that these exercises are bad.

The problem is the total bill.

BBB already builds in a lot of supplemental volume on purpose.

Wendler’s published BBB challenge therefore keeps the remaining assistance comparatively restrained. Supplemental work is meant to stay the central volume block, not the opening act of another complete hypertrophy session.

So a useful question is:

Which movement is still missing from my training?

rather than:

Which exercise could I still squeeze in somehow?

Why BBB and a calorie deficit can be a difficult combination

Muscle-building programs do not suddenly stop working entirely the moment you eat less.

But the arithmetic changes.

High training volume raises the demands on your recovery, while a substantial calorie deficit reduces the resources available.

That does not mean BBB is off limits during a diet.

It means:

You should check the load against your recovery particularly critically.

If your main goal right now is weight loss and you barely recover from 5×10 squats, there is little to gain from forcing BBB through on principle.

The program is a tool, not a loyalty test.

BBB is not automatically a permanent state

One of the more interesting developments in the later 5/3/1 system is the idea of deliberately alternating different training emphases.

BBB can make sense in a phase where supplemental volume is the priority, for instance.

That can be followed by a phase in which the volume comes back down and intensity is emphasised again.

This stops

“BBB is working well”

from turning into the conclusion:

“So I should do BBB forever.”

Training does not have to look the same every week in order to be consistent.

A practical example

Assume:

Squat TM = 140 kg

Your main work in week 1:

• 90 kg × 5
• 105 kg × 5
• 120 kg × 5+

Then BBB at 50 %:

70 kg × 10 × 5

The first two sets feel easy.

The third becomes noticeable.

On the fourth you feel the fatigue.

The fifth is demanding but stays technically clean.

That is entirely plausible.

You do not need to turn those 70 kg into 85 kg straight away just because set 1 was easy.

If six weeks later you handle the same structure cleanly with a slightly higher Training Max, progression has already happened.

BBB in hitPR

In hitPR, the volume-oriented 5/3/1 structure is covered by Wave periodisation (volume).

The plan combines:

• 5/3/1-based main work
• 5×10 supplemental work
• a conservative starting weight for the volume block
• assistance
• a cyclical progression of the Training Max

That lets main work and 5×10 be tracked separately.

Which is particularly interesting with BBB: a successful session does not consist only of your heaviest set going up.

Fifty cleanly completed reps at a weight that climbs over time are progression too.

Conclusion

Boring But Big is simply built, but not arbitrary.

The key points:

• BBB means 5×10 supplemental work after the main work.
• 50 % TM is a sensible starting point and one Wendler has used.
• Higher percentages exist, but have to be viewed in the context of the specific program.
• The well-known 50/60/70 % challenge deliberately reduces main work intensity in exchange.
• Judge the weight by the quality of all five sets and your subsequent recovery, not by set 1.
• FSL and BBB are not simple synonyms for “strength” and “muscle growth” — they distribute volume, load and fatigue differently.
• More assistance is not automatically better with BBB.
• A good BBB session should challenge you without wrecking the rest of your training week.

So the actual goal is not:

the heaviest possible 5×10.

It is:

the most productive 5×10 you can still recover from.

Sources

• Jim Wendler: 5/3/1, 2nd Edition.
• Jim Wendler: Beyond 5/3/1.
• Jim Wendler: 5/3/1 Forever.
• Jim Wendler: Boring But Big, 3 Month Challenge
• Jim Wendler: 5x5 First Set Last vs Boring But Big