Understanding your FTP training zones
The zones below follow Andrew Coggan's widely used seven-level power-training-zone model, expressed as a percentage of FTP.
| Zone | % of FTP | Physiological focus |
|---|---|---|
| Zone 1 — Active recovery | Below 55% | Easy recovery riding |
| Zone 2 — Endurance | 56% – 75% | Aerobic base training |
| Zone 3 — Tempo | 76% – 90% | Moderate sustained effort |
| Zone 4 — Lactate threshold | 91% – 105% | Sustainable-threshold intensity |
| Zone 5 — VO2 max | 106% – 120% | Maximal aerobic power |
| Zone 6 — Anaerobic capacity | 121% – 150% | Short, very high-intensity efforts |
| Zone 7 — Neuromuscular power | Above 150% | Maximal sprint efforts |
- The 95%-of-20-minute-power convention is a practical field-test approximation; individual variation means true one-hour FTP can differ from this estimate, particularly for riders with unusual anaerobic-to-aerobic power profiles.
- FTP changes with training and detraining, so periodic retesting (commonly every several weeks within a structured training block) keeps zones current.
- Power zones are training-intensity guides based on a threshold estimate, not fixed physiological categories; two riders with the same FTP can have different absolute power outputs across zones depending on their power profile.
- Pacing errors — starting the 20-minute test too hard and fading, or not pushing hard enough throughout — directly bias the FTP estimate in either direction.
What is FTP (Functional Threshold Power)?
Functional Threshold Power (FTP) is the highest average power output a cyclist can sustain for about an hour without progressively fatiguing, a concept popularized by Hunter Allen and Andrew Coggan in their book Training and Racing with a Power Meter. It is the standard reference point for setting power-based training zones in cycling, analogous to how heart-rate zones are built around a threshold heart rate.
Because sustaining a true maximal 60-minute effort is demanding and impractical to test frequently, the common field-test convention estimates FTP from a shorter, maximal 20-minute effort, discounted by 5% to approximate the lower power sustainable for a full hour. This 20-minute-test convention is widely used in cycling coaching and power-meter training software.
The 95% approximation works reasonably well for many riders but is not exact for everyone — riders with strong anaerobic capacity may sustain a 20-minute effort at a higher relative intensity than their true one-hour threshold, while others may pace a 20-minute test closer to their actual sustainable threshold. Periodic retesting and, where available, longer-duration field data help refine the estimate over time.
How to use this FTP calculator
- Warm up thoroughly, then complete a maximal, evenly paced 20-minute effort on a bike with a power meter or smart trainer.
- Record your average power for those 20 minutes.
- Enter that 20-minute average power, and your body weight for the watts-per-kilogram figure.
- Read your estimated FTP and the resulting seven Coggan training zones.
The formula behind FTP estimation
FTP is estimated as 95% of the average power sustained during a maximal 20-minute test — a standard field-test approximation, not a direct 60-minute measurement.
Worked example: a 20-minute average power of 250 W gives an estimated FTP of 250 × 0.95 ≈ 237.5 W. For a 75 kg rider, this is approximately 237.5 ÷ 75 ≈ 3.17 W/kg.
Training zones are then calculated as percentage bands of the estimated FTP, following the Coggan seven-level power-training-zone model widely used in cycling coaching.
Common mistakes
- Pacing the 20-minute test unevenly — starting too hard and fading lowers the average power and underestimates true threshold capability.
- Skipping an adequate warm-up before the test, which can suppress power output and produce a lower, less representative estimate.
- Not retesting periodically as fitness changes, leading to training zones based on an outdated FTP.
- Confusing FTP with maximal sprint power — FTP describes roughly hour-long sustainable output, an entirely different physiological demand from a short maximal sprint.
- Comparing watts-per-kilogram figures across riders without considering that absolute power (not just relative power) matters for flat, non-drafting or heavier-rider scenarios such as time trials.
Preguntas frecuentes
What is FTP in cycling?
FTP (Functional Threshold Power) is the highest power output a cyclist can sustain in a quasi-steady state for approximately one hour. It is the standard reference point used to set power-based training zones in cycling.
How is FTP calculated from a 20-minute test?
The common field-test convention estimates FTP as 95% of the average power sustained during a maximal, evenly paced 20-minute effort, since a true 60-minute maximal test is demanding to perform regularly.
How accurate is the 95% FTP estimate?
It is a widely used approximation that works reasonably well for many riders, but individual variation exists — riders with different anaerobic-to-aerobic power profiles may find their true one-hour threshold differs somewhat from the 95%-of-20-minute estimate.
What are Coggan's power training zones?
Andrew Coggan's seven-level power-training-zone model expresses training intensities as percentage bands of FTP, ranging from Zone 1 (active recovery, below 55% of FTP) to Zone 7 (neuromuscular power, above 150% of FTP), each targeting a different physiological training focus.
How often should I retest my FTP?
FTP changes as fitness improves or declines, so many structured training plans include periodic retesting — commonly every several weeks — to keep power zones aligned with current fitness.
What is a good watts-per-kilogram FTP?
Watts per kilogram depends heavily on rider category, training background and body composition, and varies enormously between recreational and elite riders. This calculator reports the figure for context, but there is no single universal benchmark independent of rider level and cycling discipline.
Referencias
- Allen H, Coggan A, McGregor S. Training and Racing with a Power Meter. VeloPress.
- Coggan A. Power training levels for cycling — the Coggan seven-zone power-training-zone model. TrainingPeaks.
- American College of Sports Medicine. ACSM's Guidelines for Exercise Testing and Prescription, 11th edition. Wolters Kluwer, 2021.