the format

Crucible Block Language

A plain-text grammar for powerlifting programs. Deterministic. Human-readable. Designed to travel.

Spreadsheets Don’t Travel Well

Coaches write programs in spreadsheets. Every one looks different. Different columns, different conventions, different ways of writing the same set. When an athlete imports the file into an app, software has to guess at the structure. A single misread cell can land in the gym.

CBL solves this by being the canonical form. Workshop renders to it. The Crucible iOS app reads it. Coaches can hand-author it. Every part of the system speaks the same language, so nothing has to be guessed.

A Block in 12 Lines

BLOCK Spring Prep
WEEKS 4
UNIT lbs
START 2026-03-02

SCHEDULE
  DAY 1 MON
  DAY 2 WED
  DAY 3 FRI

WEEK 1
  DAY 1
    Squat 5x5 @rpe:7
    Bench 3x8 @rpe:7

That’s the whole grammar. No XML, no JSON, no hidden state. What you see is what every Crucible tool reads.

Why Plain Text Wins

Send It Anywhere

A coach can paste a block straight into a text message. The athlete pastes it back into Workshop or imports it on their phone. No attachments, no accounts, nothing to install.

Easy to Read, Easy to Tweak

CBL reads top to bottom like a training log. Coaches can adjust a single line and resend. Athletes can see what changed without comparing two spreadsheets cell by cell.

One File, Both Sides

The same block holds the prescription and the actuals. When an athlete logs a session, what they really lifted lands right next to what was written. The coach gets the full picture back in one file.

One Format. Every Surface.

CBL is the seam between every Crucible product. Each tool generates or consumes the same plain text, so there is never a translation step that loses information.

  1. Workshop

    Build a program in the grid editor. CBL is generated live; download as .xlsx or copy the text directly.

  2. Crucible iOS

    Athletes import a CBL block, log sets in the gym, and the actuals are stored alongside the prescription in the same format.

  3. Back to the Coach

    Athlete-logged blocks round-trip cleanly. Coaches see what was prescribed and what actually happened, in one file.

See It in Action

Open the Workshop and watch CBL update line by line as you build a program. Or start from the Free Program and read its CBL to learn the format by example.