Load, fitness, form, and Performance Index

Brick uses familiar endurance-training load concepts alongside a proprietary capability trend. You do not need the formulas — you need the story they tell about fitness, fatigue, and race readiness.

Fitness, fatigue, and form

• CTL (fitness) — chronic training load; longer-term work capacity.
• ATL (fatigue) — acute load; how heavy the recent days have been.
• TSB (form) — roughly fitness minus fatigue; freshness for key days and races.

These inform readiness, ease-week logic, and projections. They are not the only story — compliance, limiters, and thresholds matter too.

Brick Performance Index

BPI is a proprietary multi-sport capability trend: how bike, run, and swim output are moving relative to your own baselines. Think "am I getting more capable?" rather than "is my CTL high?" Exact calculation stays internal.

Goal likelihood and race readiness

With a goal time, Brick projects bands such as on track, stretch, and at risk, with plain-language drivers (compliance, thresholds, disruption, and more).

Without a goal time, you still get completion-oriented race readiness — ready, building, or not ready — so A-race weeks are not a surprise.

How to use these

• Watch trends over weeks, not day-to-day noise.
• Pair a "stretch" goal band with honest calibration and key-session compliance.
• Let proposals handle acute fatigue instead of inventing your own deload mid-week. Proposals.