How Plan Layers Work

How Pheidi modifies your plan without losing the original.

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Non-Destructive Overlays

Every modification to your plan — vacations, injuries, manual edits, redistribution — is applied as a layer on top of the original plan. The base plan data in the database is never modified. Layers are re-applied each time your plan loads.

This means you can always "undo" any modification by removing the overlay, and your original plan is restored exactly as it was.

Layer Application Order

Layers are applied in a specific order, with later layers taking precedence:

1. Vacations — reduce or zero out workouts during time off
2. Injury — apply severity-based distance reductions
3. User Edits — manual overrides to workout type, distance, or load
4. Redistribution — spread removed miles across future easy runs

Redistribution runs last so it can see the final state of all workouts including vacation/injury reductions and user overrides.

How Each Layer Works

• Vacation layer — applies the vacation's load percentage (0% for full rest, or a custom percentage for light mode) to each affected workout
• Injury layer — skips workouts already modified by vacation; applies severity-based reductions to future workouts only
• User edit layer — replaces planned values with your manual overrides and tracks the delta miles for redistribution. Switching to a non-run type (or zero distance) clears run-only fields like pace zone, warm-up, and cool-down.
• Day off — taking a day off is a special user edit: it creates an override that zeros the workout out (with the DayOff modifier) and queues a matching redistribution so the missed miles can be picked up across future easy runs.

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Research & evidence

Science behind this feature from pheidi.training.

• Running Training Plan: The Complete Guide Pillar hub linking 48+ deeper dives — start here for the full picture.
• Handling Missed Runs 10-day rule, make-up strategies, and when doubling up backfires.
• Training Disruption: Accept, Don't Cram Evidence-based recovery after unplanned breaks.
• Rescheduling Workouts: Rules How to shift runs without breaking the week.

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See also

• How Schedule Flexibility Works How Pheidi adapts your training plan when life gets in the way: day blocking, workout swapping, and automatic reflow that preserves the overall training load.
• How Vacation Scheduling Works What happens to your training plan when you schedule time off: date-range blocking, load redistribution, and graduated return to normal volume.
• How Injury Management Works How Pheidi adjusts your training plan when you report an injury: severity-based volume reductions, graduated return-to-running, and pain-based progression gates.