Switching periodization model mid-season

Where periodization is set

Periodization is a per-Race choice in Grepiac (the Race.periodization field on each race). The four valid choices are linear, reverse, block, undulatory. See Choosing a periodization model.

The choice is not on the macrocycle; it lives on each race. You can have linear on one race and reverse on the next.

When to switch mid-season

You signed an athlete up for linear and several weeks in, something is wrong. Common cases:

Linear feels boring: the athlete is bored of long aerobic blocks and is losing motivation. Reverse adds intensity earlier, which sometimes helps engagement.
Reverse is producing injury: intensity early without enough volume base is sometimes injury-prone for newer athletes. Move to linear.
Block leaves one sport stale: an athlete who feels great in bike block but lost their swim feel might be better served by undulatory or linear.
Undulatory schedule clashes with life: the high/low weekly pattern requires consistency that some life patterns cannot deliver. Switch to linear with planned recovery weeks instead.

How to switch in Grepiac

Open the race edit page (/coach/race/<race_id>/edit/).
Change the periodization dropdown to the new value.
Save.
Edit the macrocycle plan (config_json) to match the new model. The periodization tag on the race is a label; making it match in practice requires editing the plan structure too.
Write a CoachNote explaining the change.

What Grepiac does NOT do automatically

The periodization tag on a race does not auto-rebuild the macrocycle.
Changing the tag mid-season does not alter the computed Base / Build / Peak / Taper phases on the season view (those are anchored to dates, not to the periodization tag).
Existing CalculatorResults and assessments are unaffected.

When NOT to switch

Inside the last 6 weeks before an A race. Too late. The athlete is into peak/taper and switching the model creates more chaos than improvement.
After 2 consecutive bad weeks without other signal. Two bad weeks might be life stress, illness brewing, or heat. Address the cause, not the model.
On every gut feel. Periodization is a coarse-grained decision. Switching every few weeks defeats the purpose of having one.

A note on hybrid approaches

The four periodization values cover the common patterns, but many real plans are hybrids (e.g. linear with block elements for swim, reverse for the bike). Grepiac stores one tag per race. Pick the best fit and document the actual structure in your macrocycle plan config and CoachNotes.