Fitness, Fatigue, Form Explained — Visualise Training Status
Fitness, Fatigue and Form are the three core metrics of modern power-based cycling training. Together they paint a simple but powerful picture of your training status — readable any day, data-driven, no more guessing by feel.
What does Fitness mean in this model?
Fitness measures your long-term training capacity over the past 42 days. It is a weighted average of your daily training load points, and it grows slowly — adaptations take time.
The higher your Fitness value, the more training your body can handle. But a high Fitness alone says nothing about how rested you currently are. Professional cyclists often run a Fitness value of 100–150 in season; an ambitious amateur typically sits at 50–80.
What does my Fitness value mean?
| Fitness Value | Meaning | Typical Profile |
|---|---|---|
| < 30 | Low fitness level | Beginner, after a long break |
| 30–50 | Good base fitness | Regular recreational cyclist |
| 50–80 | Solid race fitness | Ambitious amateur |
| 80–110 | High fitness | Competitive racer, high volume |
| > 110 | Pro-level fitness | Professionals, elite amateurs |
What is Fatigue?
Fatigue measures the load from the last 7 days — a weighted average of your daily training load points. It represents how much load your body is currently processing.
A high Fatigue value means you have trained a lot recently. That isn't bad — without stress there is no adaptation. But if Fatigue stays much higher than Fitness for long stretches, overtraining becomes a real risk.
What is Form?
Form is the simplest of the three: Fitness minus Fatigue. It shows how rested you are relative to your training level.
A positive Form means you are rested (Fitness outweighs Fatigue) — the ideal state for races or hard tests. A negative Form indicates fatigue — typical during intensive training blocks.
Interpreting Form values
| Form Range | State | Recommendation |
|---|---|---|
| > +10 | Very fresh / over-recovered | Increase intensity, add volume |
| 0 to +10 | Fresh, good form | Ideal for racing or FTP test |
| −5 to 0 | Slightly fatigued | Normal during training |
| −15 to −5 | Build phase, moderate fatigue | Keep training, monitor recovery |
| < −15 | Highly fatigued | Plan a recovery week |
| < −25 | Overreaching risk | Reduce load immediately |
The three curves over time
Plotting Fitness, Fatigue and Form as curves over time gives you the central analysis tool of data-driven cycling training. At a glance you see:
- How your Fitness has developed across the season
- When you were most fatigued (Fatigue peaks)
- What your Form was like before races
- Whether your tapering worked
How to use Fitness, Fatigue and Form in your training
Build Phase (Base & Build)
The goal is steadily rising Fitness. Fatigue often sits 10–20 points above Fitness, Form is negative (−5 to −20). This is normal and desired — stress creates adaptation.
Rule of thumb: increase Fitness by a maximum of 5–7 points per week, otherwise injury risk increases.
Recovery Week
Every 3–4 weeks, reduce volume by 40–60%. Fitness drops slightly, Fatigue falls sharply, Form moves positive. After the recovery week you can train harder again.
Tapering Before Races
2–3 weeks before your target event: sharply reduce volume, maintain intensity. Fitness drops slightly (minimal fitness loss), Fatigue drops sharply, Form rises to +5 to +15. This is the target form for competition.
Fitness, Fatigue and Form automatically in WattRun
WattRun computes the three metrics automatically from your FIT files and Strava activities. The progression curve is visible directly in the dashboard — always up to date, no manual effort required.
Start for free →Free · No subscription · FIT upload or Strava sync