5/3/1 Templates: How to Choose the Right One

The biggest source of confusion in 5/3/1 isn’t the main work — that part is fixed. It’s the templates: BBB, FSL, SSL, Triumvirate, Building the Monolith, Leaders and Anchors. New lifters drown in the acronyms and pick one at random. This guide maps the whole landscape so you can choose deliberately.

If you’re brand new to the program, start with the complete guide to 5/3/1 first, then come back here to choose a template.

First: What a “Template” Actually Controls

Every 5/3/1 session has three layers, and a template only changes the last two:

1. Main work — your three working sets at the standard percentages. This never changes between templates. It’s the same for everyone.
2. Supplemental work — extra volume on the main lift or a close variation, done right after your main sets. This is what most “templates” actually define.
3. Assistance work — push/pull/single-leg/core movements that round out the session.

When someone says “I’m running BBB,” they mean their supplemental work is Boring But Big. The main work underneath is identical to every other template. Keep that distinction clear and the acronyms stop being intimidating.

The Templates at a Glance

Boring But Big (BBB)

The most popular starting template. After your main work, you do 5 sets of 10 on the main lift (or a variation) at 50–60% of your training max. It’s a huge dose of volume that builds size and toughens you up — at the cost of long, demanding sessions. Read the full Boring But Big guide.

FSL and SSL

First Set Last has you repeat your first working set’s weight for extra sets — a lighter, recovery-friendly way to add volume. Second Set Last uses the heavier second-set weight, splitting the difference between FSL’s ease and BBB’s intensity. Our FSL vs BBB vs SSL comparison breaks down exactly when to use each, and the SSL deep-dive covers that template in detail.

The Triumvirate

The classic assistance template from the original book: each main lift plus exactly two assistance exercises, five sets each. It’s the antidote to accessory overload — focused, finite, and effective. See the Triumvirate guide.

Building the Monolith

Not a supplemental template but a complete 6-week size block — high-frequency squatting and pressing, a 20-rep widowmaker, mountains of chins and dips, and a serious eating requirement. It’s an advanced phase you run once and recover from, not your day-to-day program. Full details in the Building the Monolith guide.

5/3/1 Forever

The framework for tying cycles together over the long haul. Forever introduces Leader and Anchor cycles, 5’s PRO, and the 7th Week Protocol, alternating volume-focused and intensity-focused blocks so the program keeps working for years instead of stalling. This is where intermediate lifters go once a single repeating template gets stale.

How to Choose

A simple decision path:

• New to 5/3/1? Run FSL or BBB for a few cycles. Don’t overthink it.
• Want size and can handle the volume? BBB, then consider a Building the Monolith block when you have a base.
• Want simple, focused accessories? The Triumvirate.
• Been running 5/3/1 a while and stalling? Move to the Forever Leader/Anchor structure.
• Short on time? FSL keeps sessions tight.

Whatever you pick, the main-work percentages stay the same — generate them with the 5/3/1 calculator and bolt the template on top.

Let the Coaching Pick for You

Choosing and adjusting templates is the hardest judgment call in self-coached 5/3/1 — and the place most lifters get stuck, either grinding a template that no longer fits or program-hopping every week.

Train531 generates your main work from your training max and uses an AI coach to prescribe supplemental and accessory work that matches your goals, equipment, and training history — then adapts it as you progress. You get the structure of a chosen template without having to be your own programmer. See how it works.