Authoring a 5/3/1 Cycle, Programmatically

Mix.install([
  {:wpl_validator, path: Path.join(__DIR__, "..")},
  {:jason, "~> 1.4"},
  {:kino, "~> 0.13"}
])

Goal

Build a Wendler 5/3/1 four-week cycle for the squat as a plain Elixir map, validate after each step, and serialize to JSON at the end. This is the shape your code generators / authoring tools should produce.

Building blocks

defmodule SetReps do
  @moduledoc "Helpers for assembling exercise prescriptions."

  def squat(%{sets: sets, reps: reps, percent_1rm: pct, rest_s: rest}) do
    %{
      "id" => "ex_squat",
      "type" => "exercise",
      "exercise_ref" => "back_squat",
      "name" => "Back Squat",
      # Schema v1.3.0+: muscle-group + movement-pattern tags. Lets a
      # consuming app compute weekly volume per muscle group without an
      # out-of-band exercise→muscle map.
      "primary_muscles" => ["quadriceps", "glutes"],
      "secondary_muscles" => ["hamstrings", "spinal_erectors"],
      "movement_pattern" => "squat",
      "prescription" => %{
        "type" => "sets_reps",
        "sets" => sets,
        "reps" => normalize_reps(reps),
        "weight" => %{"type" => "percentage_1rm", "value" => pct, "unit" => "percent"},
        "rest" => %{"value" => rest, "unit" => "seconds"},
        # Schema v1.2.0+: structured Tempo. 3-1-X-0 = 3s eccentric, 1s
        # pause, explosive concentric, 0s pause top.
        "tempo" => %{
          "eccentric" => 3,
          "pause_bottom" => 1,
          "concentric" => 0,
          "pause_top" => 0,
          "explosive_concentric" => true
        }
      }
    }
  end

  defp normalize_reps(n) when is_integer(n), do: %{"target" => n}
  defp normalize_reps({min, max}), do: %{"min" => min, "max" => max}
  defp normalize_reps(:amrap_5), do: %{"min" => 5}
end

Week templates

5/3/1 weeks (top set only — accessories omitted to keep this readable):

• W1 — 5/5/5+ at 65/75/85% 1RM
• W2 — 3/3/3+ at 70/80/90% 1RM
• W3 — 5/3/1+ at 75/85/95% 1RM
• W4 — deload 5/5/5 at 40/50/60% 1RM

weeks = [
  {1, [{5, 65}, {5, 75}, {:amrap_5, 85}]},
  {2, [{3, 70}, {3, 80}, {:amrap_5, 90}]},
  {3, [{5, 75}, {3, 85}, {1, 95}]},
  {4, [{5, 40}, {5, 50}, {5, 60}]}
]

build_day = fn week_no, sets ->
  activities =
    sets
    |> Enum.with_index(1)
    |> Enum.map(fn {{reps, pct}, i} ->
      SetReps.squat(%{sets: 1, reps: reps, percent_1rm: pct, rest_s: 180})
      |> Map.put("id", "ex_squat_set_#{i}")
    end)

  %{
    "id" => "d_squat_w#{week_no}",
    "day_of_week" => 1,
    "name" => "Squat — Week #{week_no}",
    "type" => "training",
    "blocks" => [
      %{
        "id" => "main",
        "type" => "main",
        "order" => 1,
        "structure" => "straight_sets",
        "activities" => activities
      }
    ]
  }
end

build_week = fn week_no, sets ->
  base = %{
    "id" => "wk_#{week_no}",
    "name" => "Week #{week_no}",
    "order" => week_no,
    "days" => [build_day.(week_no, sets)]
  }

  # Schema v1.2.0+: flag the deload week so downstream tools can render
  # a "Deload" badge and analytics can drop volume from week-over-week
  # progression curves.
  if week_no == 4, do: Map.put(base, "is_deload", true), else: base
end

built_weeks = Enum.map(weeks, fn {n, sets} -> build_week.(n, sets) end)
length(built_weeks)

Assemble the plan

plan = %{
  "$schema" => "https://wpl.dev/schemas/wpl/v1.schema.json",
  "version" => "1.0.0",
  "plan" => %{
    "id" => "plan_531_squat_cycle",
    "name" => "5/3/1 Squat — 4 Week Cycle",
    "description" => "Wendler 5/3/1 main lift cycle for back squat.",
    "type" => "workout",
    "visibility" => "private",
    "metadata" => %{
      "tags" => ["531", "strength", "squat"],
      "difficulty" => "intermediate",
      "estimated_duration_days" => 28,
      "language" => "en"
    },
    "goals" => [
      %{
        "id" => "goal_531",
        "type" => "primary",
        "category" => "strength",
        "name" => "Increase squat 1RM"
      }
    ],
    "phases" => [
      %{
        "id" => "phase_cycle_1",
        "name" => "Cycle 1",
        # Schema v1.2.0+: periodization role lets a coach app surface
        # "you're in an intensification cycle" without re-deriving it.
        "type" => "intensification",
        "order" => 1,
        "duration" => %{"value" => 4, "unit" => "weeks"},
        "weeks" => built_weeks
      }
    ]
  }
}

:assembled

Validate

result = WPL.Validator.validate(plan)

case result do
  %WPL.Validator.Result{valid?: true, errors: []} ->
    Kino.Markdown.new("✅ **Plan is valid** — ready to compile/serialize.")

  %WPL.Validator.Result{errors: errors} ->
    rows =
      Enum.map(errors, fn e ->
        %{severity: e.severity, code: e.code, path: e.path, message: e.message}
      end)

    Kino.DataTable.new(rows)
end

Serialize to JSON

json = Jason.encode!(plan, pretty: true)
Kino.Markdown.new("```json\n" <> json <> "\n```")

What to try next

• Change a percentage to a string ("85") and re-run — observe a :schema_violation with keyword: type.
• Duplicate an id between two activities and watch a :duplicate_id error pop up at scope: "day:...".
• Add a phase with duration: %{"value" => 3, "unit" => "weeks"} but only one week in the array — see the :phase_duration_mismatch warning (note: warnings don’t make the plan invalid).
• Add "athlete_thresholds" => %{"body_weight_kg" => 80, "one_rm" => [...]} at the plan level, then express the prescription weight as %{"type" => "percentage_1rm", "value" => 75} — consumers can resolve the absolute load downstream.