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FTP Explained: The One Number That Organizes Cycling Training
FTP — functional threshold power — is the highest power you can sustain for roughly an hour, measured in watts. It matters because it is the anchor for every training zone, the best single predictor of sustained climbing and time-trial ability, and a number you can improve and verify. You need a power meter or smart trainer to measure it; without one, threshold heart rate serves the same organizing role less precisely.
The number that actually matters: W/kg
Raw watts favor big riders; hills do not. Watts per kilogram — FTP divided by body weight — is the great equalizer. Rough amateur benchmarks: around 2.0 W/kg for new riders, 2.5–3.0 for regular recreational cyclists, 3.5–4.0 for strong amateur racers, 4.5–5.0 for elite amateurs, and 5.6+ sustained for professionals. A 70 kg rider with a 210 W FTP (3.0 W/kg) will climb with an 85 kg rider holding 255 W.
Three ways to test
- 20-minute test: after a hard warm-up, ride 20 minutes absolutely as hard as you can sustain evenly; FTP ≈ 95% of the average power. The classic, and brutal.
- Ramp test: power increases every minute until you fail; FTP ≈ 75% of the last completed minute. Shorter and less pacing-dependent — the default on most trainer apps — but tends to overestimate for riders with strong sprints.
- Longer efforts: your best 40–60 minute power from a hard climb or time trial is FTP nearly directly, no multiplier games.
Whichever you choose, keep it constant. The value of FTP is trend, and changing protocols corrupts the trend.
Raising it
Two proven levers: volume of easy aerobic riding (zone 2 builds the mitochondrial base everything rests on) and repeated time near threshold — sessions like 2 × 20 minutes at 95–100% FTP or 4 × 8 minutes slightly above it, once or twice weekly. Beginners commonly gain 10–20% in their first structured season; veterans fight for 2–5% a year. Recovery is where the adaptation happens, so consecutive hard days mostly produce fatigue, not fitness. See the weekly structure in our training zones guide, and fuel the work properly with our nutrition guide.
Keep exploring
Put these numbers to work with the free CalculateBike speed and calorie calculator, browse the cycling gear guide, or read more cycling articles. Prefer two feet to two wheels? Our sister tools CalculateSteps and CalculateRun cover walking and running.