Race Shape › Answers › What is FTP, and how do I test it?
AnswersWhat is FTP, and how do I test it?
FTP, or Functional Threshold Power, is roughly the highest power in watts a cyclist can sustain for about an hour. It is the anchor for cycling power zones. You can estimate it without riding flat out for an hour: take 95% of your average power over a hard 20-minute test, 90% of an 8-minute test, or 75% of the best minute in a ramp test.
From a test to an FTP
| Test | Estimated FTP |
|---|---|
| 20-minute test at 263 W | FTP ≈ 250 W (× 0.95) |
| 8-minute test at 278 W | FTP ≈ 250 W (× 0.90) |
| Ramp test, best minute 333 W | FTP ≈ 250 W (× 0.75) |
Each test estimates the same thing differently. The 20-minute test is the most widely used. The 8-minute test is shorter and kinder to pacing mistakes. The ramp test is easiest to execute but tends to flatter riders with a strong short-duration kick, so treat its number with a little caution.
Zones for an FTP of 250 W
| Recovery | 0–138 W |
|---|---|
| Endurance | 140–188 W |
| Tempo | 190–218 W |
| Sweet spot | 220–235 W |
| Threshold | 238–263 W |
| VO₂max | 265–300 W |
Altitude, and why to test where you ride
An FTP tested at the coast is too high for riding in Johannesburg, and one tested in Johannesburg is too low for racing at the coast. The simplest fix is to test where you train. Race Shape corrects only for the difference between where you tested and where you ride.
Common questions
Can I train by power without an FTP?
Not usefully. Without FTP the zones have no anchor. Race Shape falls back to heart rate, and then to perceived effort, and tells you which it is using.
How often should I retest?
Every six to eight weeks in a block, and after a break. FTP moves with training.
Is an indoor FTP the same as outdoors?
Often slightly lower indoors, because of heat and the lack of terrain variation. Test in the setting you do your key sessions.
Sources
- Allen, H. & Coggan, A. Training and Racing with a Power Meter.