Functional Threshold Power (FTP) is the highest average power a cyclist can hold for roughly one hour. It anchors your training zones, TSS calculations, and interval targets — making every workout intensity-specific rather than guesswork.
Who this is for
Cyclists with a power meter or smart trainer who want structured intervals and accurate training load tracking.
If you do not have power, threshold heart rate or pace can serve a similar role for zone setting.
How to test FTP
The classic 20-minute test: warm up thoroughly, ride 20 minutes all-out, then multiply average power by 0.95 to estimate FTP.
A ramp test on a smart trainer is another common option — it estimates FTP from the final stage you complete before failure.
Retest every 6–8 weeks during build phases, or after a block of consistent training.
FTP-based training zones
Most systems use 7 zones derived from FTP percentage:
| Zone | % FTP | Purpose |
|---|---|---|
| Z1 Active Recovery | < 55% | Easy spinning |
| Z2 Endurance | 56–75% | Aerobic base |
| Z3 Tempo | 76–90% | Muscular endurance |
| Z4 Threshold | 91–105% | Lactate threshold |
| Z5 VO2 Max | 106–120% | Aerobic capacity |
| Z6 Anaerobic | 121–150% | Short power |
| Z7 Neuromuscular | > 150% | Sprints |
Sample FTP progression week
For a cyclist with FTP 250 W, a build week might include:
- Tuesday: 5 × 5 min @ 105% FTP (VO2)
- Thursday: 2 × 20 min @ 88% FTP (sweet spot)
- Saturday: 3 h @ 65–70% FTP (endurance)
Common mistakes
- Testing FTP when fatigued or under-fueled.
- Never retesting — zones become stale as fitness changes.
- Doing all training near threshold instead of polarized easy/hard distribution.
Sources
Using Vo2Max
Set your FTP in Vo2Max's fitness profile and every generated workout is calibrated to your zones. Sync from Strava to keep it current.