Hub · power models
Power Training Zones
Power zones for cycling and running: Coggan FTP 7-zone with Sweet Spot, Critical Power and W′, and Stryd running power. Anchor every watt to a real test.
Power Zone Calculator (FTP & Coggan Zones)
Functional Threshold Power (FTP) is the highest power you can hold for about an hour. The Coggan model sets seven zones from it: Endurance (Z2) is 56–75% FTP and Threshold (Z4) is 91–105%. At an FTP of 250 W, Z2 is 140–188 W, Z4 is 228–263 W, and Sweet Spot is 220–235 W.
Critical Power Calculator (CP & W′)
Critical Power (CP) is the asymptote of the power–duration curve, the highest power you can sustain almost indefinitely. From two maximal efforts, CP = (P1·t1 − P2·t2) ÷ (t1 − t2) and W′ = (P1 − CP)·t1. A 300 W 3-minute and 250 W 10-minute effort give CP ≈ 229 W and W′ ≈ 12.9 kJ.
Running Power Zones Calculator
Running power zones anchor to your running Critical Power (CP), not cycling FTP. The two are not interchangeable. Stryd's five-zone model runs from Easy below 80% CP to Repetition above 115%. At a running CP of 280 W, Threshold tops out at 280 W and Repetition starts above about 322 W.
Which power model should you use?
Power is the most honest number in endurance sport, but only once it is anchored. Each model below fixes your zones to a different test, so pick the one whose test you can actually repeat.
| Model | Anchored to | Best for | You need |
|---|---|---|---|
| Power Zones (FTP) | FTP, the power you could hold for about an hour | Cyclists using Coggan's seven zones, the default in most training platforms | FTP from a 20-minute test, a ramp test or a long hard ride |
| Critical Power | Critical Power and W′, fitted from several maximal efforts | Modelling short hard efforts and how much you have left above threshold | Two or three all-out efforts of clearly different durations |
| Running Power | Running power from a footpod or watch | Runners on hills and trails, where pace misleads and heart rate lags | A device that reports running power, plus a threshold effort |
Swipe sideways for every column. Anchor every watt to a test you actually completed.
FTP has an expiry date
FTP is not a fixed property of you, it is a snapshot of your current fitness. It rises through a build block and falls through illness, a heavy work period or an off-season. Zones calculated from a number you set four months ago describe an athlete who no longer exists.
Retest every six to eight weeks, or whenever a session that should be hard feels easy twice in a row. That second signal is usually the earlier one. If retesting properly is disruptive, a well-paced 20-minute effort inside a normal ride is enough to catch the drift.
Power is honest, which is exactly why it hurts
Unlike heart rate, power responds instantly and does not drift. A 300-watt effort is 300 watts in the first minute and the fortieth, in the cold and in the heat. That makes it the right tool for short intervals, where heart rate simply cannot arrive in time.
What power does not know is what the effort costs you today. Heat, fatigue, altitude and poor sleep all raise the physiological price of the same watts without changing the number. This is why experienced athletes watch power to control the session and heart rate to understand it afterwards.
Frequently asked questions
What is a good FTP?
Raw FTP means little on its own, because a heavier rider produces more watts at the same fitness. Watts per kilogram is the comparable figure: roughly 2.5 to 3.0 W/kg is a solid recreational cyclist, 3.5 to 4.0 is competitive amateur racing, and above 5.0 is elite territory. Compare yourself against your own previous test first.
How often should I test my FTP?
Every six to eight weeks during consistent training, and again after any break longer than two weeks. Testing more often than that mostly measures how fresh you were on the day. Testing less often means training to zones that describe the athlete you used to be.
Is Critical Power the same as FTP?
They are close but not identical. FTP is defined as roughly one hour of maximal effort, while Critical Power is fitted mathematically from several maximal efforts and usually lands slightly higher. Critical Power also gives you W′, the finite work available above that line, which FTP alone does not describe.
Can I use power zones for running?
Yes, with a device that reports running power. Running power is most useful where pace becomes a poor guide, on hills, trails and in wind, because it reflects the actual work rate rather than the speed over the ground. Anchor it to a running threshold effort, not to your cycling FTP, since the two are not interchangeable.
- The Coggan Power Zones: All 7 Levels Explained (% of FTP)Andrew Coggan's 7 power zones, each as a percentage of FTP: the watts range, what it trains, how it feels, and how to set yours from an FTP test.
- How to Set Your Power Zones From an FTP TestSet all seven cycling power zones from one FTP test: the 20-minute, 8-minute and ramp protocols, the factor each uses, and when to retest.
- How Enric Mas Trains (Won the Vuelta a Year After Surgery)Mas lost half of 2025 to a blood clot and was 32nd at the Giro in May. On 13 September he won the Vuelta. How the comeback was built, block by block.