Faaast notes
Inside the Adaptive Training Score.
The internal model behind Training Signature: a continuous load score with aerobic, threshold, anaerobic, muscular, and internal-response context.
The internal rule is: zones should explain the score, not define the score. A workout should not suddenly mean something different because one sample crossed a hard boundary by a few watts or a few seconds per kilometer.
The Adaptive Training Score is continuous. It can still produce a headline number for planning, but it preserves the stress signature behind that number.
Adaptive Training Score
| Component | Role |
|---|---|
| Aerobic metabolic load | The steady contribution from duration and lower-intensity work. |
| Threshold and severe-domain load | The pressure from work near and above threshold. |
| Anaerobic depletion load | The cost of repeated hard surges and short severe efforts. |
| Muscular and mechanical strain | The load from force, terrain, cadence, and impact. |
| Internal-load modifier | Optional context from heart rate, perceived effort, heat, sleep, and stress. |
Source note
This is a Faaast product model, not a published medical score. Its vocabulary borrows from established training-load ideas: external versus internal load, session RPE as an internal-load signal, critical-power and severe-domain physiology, and W-prime balance for repeated hard efforts. For day-to-day fatigue context, Faaast treats heart rate, perceived fatigue, sleep, stress, and soreness as monitoring signals in the spirit of Halson's athlete-monitoring review, not as diagnosis.
External load and internal load are not the same thing.
Power, pace, elevation, and duration describe the mechanical work. Heart rate and perceived effort describe physiological cost. Faaast should compare those signals before blending them.
If external load is moderate but internal load is high, the answer is not "try harder." It might be heat, poor sleep, dehydration, stress, illness, or simply a body asking for a lower gear. The product should surface that gap without making medical claims.
One score for planning. Full context for decisions.
The score gives the calendar a shared language. The breakdown keeps the athlete from treating every 100-point session as the same session. A long endurance ride, a punchy group ride, and a VO2 session can create similar totals while training different systems.
That is why the user-facing concept is better framed as a Training Signature. The number is the headline. The signature is the decision support.