- FTP is the most power you can hold for about an hour.
- Most workouts set their targets as a percentage of it.
- Test it every 6 to 8 weeks so your training keeps up with you.
What it means
FTP stands for functional threshold power. It is the highest average power, in watts, you could hold for about an hour if you went as hard as you could without blowing up.
Go harder than that and you can only keep it up for minutes. Go easier and you can ride for hours. FTP is the line between the two.
Why it matters
Outside, hills and wind decide how hard you ride. Indoors, a number does. A workout that says 95% for 8 minutes means 238 W if your FTP is 250, and 190 W if it is 200.
That is why the same session feels right for a beginner and for a racer. When your FTP is accurate, every interval is hard in the way it was meant to be.
Your FTP lives in Profile, under FTP and zones. Change it after a test and your next workout scales to match.
Finding yours
You do not need a lab. Two simple tests work on most smart trainers:
- A ramp test. The target climbs every minute until you cannot hold it. Short, hard and easy to repeat.
- A 20-minute test. Ride as hard as you can for 20 minutes, then take 95% of your average. It needs a trainer that can release its resistance, so you set the effort with your gears. If yours cannot, use the ramp test.
Warm up well before either test. Stop if you feel chest pain, dizziness or unusual breathlessness. If you have a heart or other medical condition, check with a doctor before hard efforts.
Not sure of your FTP yet? Choose “I Don’t Know My FTP” during setup and take the ramp test as your first ride. Hammy does not guess a value for you. If rides later feel too easy or too hard, test again. How to test your FTP walks through both tests.
Your zones
Zones split your power into bands, each one training something different. Here is how they look for a 250 W FTP.
| Zone | % of FTP | At 250 W |
|---|---|---|
| Z1 Active recovery | 0–55% | 0–137 W |
| Z2 Endurance | 56–75% | 138–187 W |
| Z3 Tempo | 76–90% | 188–225 W |
| Z4 Threshold | 91–105% | 226–262 W |
| Z5 VO₂ max | 106–120% | 263–300 W |
| Z6 Anaerobic | 121–150% | 301–375 W |
| Z7 Neuromuscular | over 150% | above 375 W |
When to retest
Every 6 to 8 weeks is a good rhythm, or sooner if threshold intervals start to feel easy. A higher number is good news: it means you got faster.
Show sources (3)Hide sources
- Burnley M, Jones AM (2018). Power–duration relationship: Physiology, fatigue, and the limits of human performance. European Journal of Sport Science, 18(1), 1–12. doi:10.1080/17461391.2016.1249524
- Klitzke Borszcz F, Ferreira Tramontin A, Pereira Costa V (2019). Is the Functional Threshold Power Interchangeable With the Maximal Lactate Steady State in Trained Cyclists? International Journal of Sports Physiology and Performance, 14(8), 1029–1035. doi:10.1123/ijspp.2018-0572
- Lillo-Beviá JR, Courel-Ibáñez J, Cerezuela-Espejo V, et al. (2022). Is the Functional Threshold Power a Valid Metric to Estimate the Maximal Lactate Steady State in Cyclists? Journal of Strength and Conditioning Research, 36(1), 167–173. doi:10.1519/JSC.0000000000003403
