How training plans are built

Brick builds your calendar with a deterministic engine — same history, prefs, and races produce the same plan. This page explains how workouts are prescribed and what drives duration vs intensity from your capabilities.

How a plan is built

Structure comes first; AI only narrates why. Nothing invents the next workout. The pipeline:

1. 1

   Inputs — history, prefs, races, limiters, thresholds

2. 2

   Season campaigns — base → build → peak → taper (fit to available weeks)

3. 3

   Volume ramp — weekly hours from demonstrated capacity toward your target

4. 4

   Weekly skeleton — longs, quality, swims, strength, fillers on your days

5. 5

   Prescriptions — archetypes hydrated into steps, load, and guidance

6. 6

   You train — sync → readiness and limiters update → proposals you approve

Philosophy and consent-gated adaptations: How Brick coaches.

What shapes the season

Your A-race (or maintain-fitness goal) anchors campaigns across the year. Available weeks decide whether you get a full base→build→peak→taper arc or a compressed / hold structure. Post-A recovery scales with race distance. B and C races overlay mini-tapers or train-through days without rewriting the whole season.

Phase jobs stay consistent: base builds foundation and controlled quality; build adds race-specific work and bricks; peak sharpens; taper protects freshness. Details: Seasons, phases, and races.

What drives weekly volume

Weekly hours start from demonstrated capacity — what you have actually done recently, with comeback credit from yearly history after a layoff. Your hours target and aggressiveness set how high the ramp aims; the engine never cuts peak volume below what you have already proven.

• Volume grows gradually toward peak across base, build, and peak.
• Periodic recovery (deload) weeks protect adaptation.
• Taper weeks step volume down so you arrive fresh, not flat.
• Sport split blends your history with a triathlon-sensible default, then nudges weak sports and limiters.

What drives session duration

Session length is not a fixed template ("elite = 5-hour ride"). It cascades from the week's hour budget:

1. Week hours from the volume ramp (and away-day or mid-week proration when relevant).
2. Sport budget — swim / bike / run share of that week.
3. Slot share — longs and key quality take priority slices of the sport budget; fillers get what remains.
4. Personal progression caps — your own history of session and long lengths limits how far a single day can stretch in the current phase.
5. Experience sets sensible floors so early sessions are real training, not stubs.

Sessions that would fall below a meaningful floor are skipped, not left as tiny placeholders. Deload weeks also shorten keystone longs. Week density (how many sessions, whether doubles appear) follows proven hours and demonstrated frequency — not a label alone.

Swim is distance-first: main sets are authored in meters; calendar duration is estimated from your CSS so load stays coherent. Bike FTP and run threshold do not size how long a ride or run is.

What drives intensity

Intensity is prescribed as a fraction of threshold — the same model for swim CSS, bike FTP, and run threshold pace. The workout type and phase choose the fraction (easy endurance, controlled threshold, race pace, VO2). Your thresholds turn those fractions into watts, pace, or heart-rate bands on the device.

• Most volume stays genuinely easy. Quality is primarily controlled threshold, with a smaller VO2 dose when the phase calls for it. Why weeks are structured.
• Experience mainly changes reps and structure inside a session — not the intensity fraction itself.
• Metric-aware execution: easy / Z2 and recovery prefer heart rate; quality bike uses power; quality run and swim use pace, with an HR ceiling on sustained quality when it matters.

Raising FTP does not automatically make the engine prescribe "harder" fractions — it makes the same fraction resolve to higher absolute power. Recalibrate when fitness changes so execution stays honest. Thresholds and zones.

Capability checklist

Different inputs drive different outcomes:

• Training history — weekly volume, session duration, week density (sessions / doubles).
• Prefs — hours target, days available, schedule placement, aggressiveness, experience floors, sports and venues.
• Thresholds — absolute targets for execution (watts / pace / HR), not the prescribed % of threshold.
• Limiters — phase length bias, sport-split nudge, which quality themes get priority. Limiters and blind spots.
• Races — season campaigns, taper, B/C overlays.