How to calculate your FTP
FTP (functional threshold power) is the highest power you can sustain for about an hour. RitmoSync uses it to set your training zones and program targets. You only need a rough estimate to start—you can refine it after a proper test.
20-minute test (recommended)
This is the most common field test. RitmoSync includes an FTP Test program with a built-in 20-minute max effort—use it on your trainer, or follow the steps below on any ride where you record average power.
- Warm up for at least 15 minutes. Include a few short harder efforts (30–60 seconds) with easy spinning between them so your legs are ready.
- Ride 20 minutes as hard as you can hold—steady, not a sprint from the gun. Aim for the highest average power you can maintain for the full interval.
- Note your average power for those 20 minutes (from your bike computer, trainer app, or RitmoSync’s session stats after the test).
- Multiply by 0.95 to estimate FTP. Most athletes cannot hold true hour-long threshold power for a full 20-minute test, so the 5% adjustment is standard.
Formula
FTP (W) = 0.95 × average power from 20‑min test (W)
Example: 220 W average for 20 minutes → FTP ≈ 209 W (round to 210 W in the app).
Enter FTP in RitmoSync
Open the menu (☰), type your FTP in watts under FTP, and save. Zones and workouts update immediately. Retest every few weeks when fitness changes.
Power zones used in RitmoSync
With FTP set, zones are calculated as percentages of that value:
| Zone | % of FTP | Typical use |
|---|---|---|
| Z1 | < 55% | Recovery, warm-up, cool-down |
| Z2 | 55–75% | Endurance |
| Z3 | 75–90% | Tempo |
| Z4 | 90–105% | Threshold / sweet spot |
| Z5 | 105–120% | VO₂ max intervals |
| Z6 | 120–150% | Anaerobic efforts |
| Z7 | > 150% | Short sprints |
No time for a test yet? Use a recent hard 45–60 minute ride: your average power is often close to FTP. Lab tests and other protocols (ramp test, 8‑min test) exist—use whatever method you trust, then enter the result as FTP in RitmoSync.