BBB vs FSL: which 5/3/1 supplemental template to run

BBB is 5x10 at 50–60% of your working max and builds size. FSL is 5x5 at your first-set weight and builds strength. Here's how to choose.

Every number checked against the Strenos app

Extra reps per main lift
50reps of BBB, 5×10
25reps of FSL, 5×5

If you want to build muscle and can recover from 50 extra reps per main lift, run Boring But Big (BBB). If strength is the goal, your sessions are short, or BBB leaves you too beat up to push your plus sets, run First Set Last (FSL).

Both templates fill the same slot in 5/3/1. You do them right after the main sets, usually on the same lift, and they take their weight from your working max (Wendler calls it the training max, or TM). What sets them apart is how much work they add and how heavy it is. Wendler himself has never named a winner. Asked about it on his site, he said the end results are closer than most people think. BBB tends to build a little more size, and FSL is easier to recover from.

What each template asks for

Boring But Big is 5 sets of 10 on the same lift you just trained. Wendler's rule of thumb is 50–60% of your working max. His original BBB article makes the point plainly: finishing all 50 reps matters more than the exact percentage. If you're newer to lifting, start lighter. He suggests three cycles at 30%, 45% and then 60%. The BBB weight stays put for the whole cycle, so week 3 is the same 5x10 as week 1. It only moves when your working max does.

First Set Last brings back the weight of your first working set after the main work is done. On the standard wave, that's 65% in week 1, 70% in week 2 and 75% in week 3. The usual versions are 5x5 and 3x5, and some lifters do a single FSL set for max reps instead. Because FSL follows the weekly wave, it gets heavier as the cycle goes on.

The numbers side by side

Take a squat day with a 200 lb working max. In week 1 the main sets are 130x5, 150x5 and 170x5+. That's about 2,250 lb before any extra reps on the plus set. Here's what each template adds on top:

BBBFSL
Sets x reps5x105x5
Week 1 weight100 lb (50%)130 lb (65%)
Week 2 weight100 lb (50%)140 lb (70%)
Week 3 weight100 lb (50%)150 lb (75%)
Extra reps per session5025
Extra volume per session5,000 lb3,250–3,750 lb
What it buildsSize and work capacityStrength and bar speed

Two things jump out. BBB gives you twice as many reps as FSL at a much lighter weight. And either template adds more volume than the main sets themselves. Most of your weekly tonnage in 5/3/1 comes from supplemental work, so the choice matters.

The short answer

If you're after size and recover well, run BBB. If you're after strength, short on time or BBB beats you up, run FSL.

Pick BBB when

  • Size is the goal. For a strength program, sets of ten on squat, bench, deadlift and press are a lot of muscle-building work.
  • You can eat and sleep for it. Fifty reps per lift on top of the main sets adds up, and your plus sets are the first place the fatigue shows.
  • You have the time. Five sets of ten with proper rest take longer than five sets of five.
  • Nothing heavy is coming up. BBB belongs at the start of a training block. Keep it out of the weeks before a test or a meet.

If you can't finish 5x10, drop the percentage. That's Wendler's own advice, and it's the first fix people suggest on Reddit. Starting BBB at 70% is the classic way to wreck the template in week one.

Pick FSL when

  • Strength is the goal. FSL sets are heavier, and Wendler expects them to move fast. If the bar slows down, your working max is probably set too high.
  • Your sessions are short. Twenty-five reps fit into a lunch break. Fifty reps of squats often won't.
  • You train something else hard. Running, a team sport or serious conditioning all draw on the same recovery. FSL leaves more in the tank.
  • BBB has stalled you. If your plus sets keep shrinking after a few BBB cycles, the obvious next move is a block of FSL, with less work and heavier sets.

Mistakes that ruin both

Grinding supplemental sets. Your plus set is where you push. Finish every supplemental set with reps to spare, and if the last two sets of BBB turn into grinders, the percentage is too high.

Stacking both on the same lift. The usual advice on r/531Discussion is to pick one. Some lifters split them by lift, for example BBB for the opposite lift (squat 5x10 on deadlift day). That still costs recovery. You're just choosing where to spend it.

Keeping full BBB on the deload. Wendler's original BBB article lets you keep 5x10 on the deload week or cut it to 3x10. Run the numbers before you decide. With a 200 lb working max, the deload sets of 80x5, 100x5 and 120x5 total 1,500 lb. Full BBB at 50% is 5,000 lb, more than three times the main work. At that point the week has stopped being a deload.

Switching every cycle. Give a template two or three cycles before you judge it. Wendler also warns against running one approach forever, so plan in blocks. Do a few cycles of BBB to build, then switch to FSL to turn that work into strength.

How Strenos sets them up

In Strenos you add BBB or FSL to a main lift, and it runs on that lift's working max, training days and weekly wave. You can set BBB to 50, 60 or 70% of the working max, with 3–6 sets of 5–15 reps. The default is 5x10. FSL gives you 3–5 sets of 5 at that week's first-set weight. On deload weeks both drop out of your plan for the reason above, and regular assistance work is cut to half the sets.

Neither template moves your working max. Only the main sets do, so a rough BBB day can't drag down next cycle's numbers. You can run both templates on weighted pull-ups and dips too. There your bodyweight counts toward the belt weight, because a percentage of the plates alone comes out far too heavy.

FAQ

Can I run BBB and FSL in the same cycle?

Yes, as long as they're on different lifts. You could run FSL on squat and deadlift and BBB on bench and press, where 50 reps cost you less recovery. Doing both after the same lift means 75 extra reps, more than either template was written for.

What percentage should I use for BBB?

Start at 50%. Wendler's general range is 50–60% of the working max. Only move up once 5x10 at your current percentage feels routine and every rep looks the same. If 5x10 is new to you, his three-cycle ramp of 30, 45 and 60% is the safer way in.

Is FSL enough for muscle growth?

It builds some, but 25 reps at 65–75% is less hypertrophy work than 50 reps at 50%. If size matters and FSL is all you can recover from, get the extra work from assistance lifts like rows, dips and lunges. Piling more supplemental sets onto the main lift is the wrong fix.

Does BBB or FSL change my working max?

No. Your working max moves on the main sets, mostly the plus set. Supplemental sets add work, but they don't test you, so a bad day of 5x10 says nothing about next cycle.

Should I do BBB or FSL on the deload week?

Drop them or cut them way back. Wendler's BBB article lets you keep 5x10 or cut it to 3x10, but with full BBB the deload stops being much of a deload. In Strenos your deload week comes without either one, so it stays a real deload.

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