What Is Functional Threshold Power (FTP)?
Functional Threshold Power (FTP) is the highest average power in watts a cyclist can sustain evenly for approximately 60 minutes. First introduced by Dr. Andrew Coggan and Hunter Allen in Training and Racing with a Power Meter, FTP represents your aerobic threshold and scales every training zone from endurance to anaerobic intervals.
Knowing your FTP lets you train with precision. Every interval, sweet spot block, and endurance session scales as a percentage of this number rather than arbitrary perceived exertion.
FTP = 20-minute average power × 0.95
The 0.95 multiplier corrects for the ~5% anaerobic contribution present during a 20-minute maximal effort compared to a true 60-minute sustainable pace.
How to perform a 20-minute FTP test
The 20-minute field test is the gold-standard protocol for measuring threshold power outside a laboratory. It requires a power meter or smart trainer and an uninterrupted road or indoor trainer session.
- Warm-up (20 min): Begin with 20 minutes of easy Z1–Z2 riding. Include three 1-minute efforts at threshold feel with 2 minutes easy between each. Finish with 5 minutes spinning.
- 5-minute opener (all-out): Ride 5 minutes at maximum effort to deplete your anaerobic reserve so the 20-minute test reflects aerobic threshold rather than sprint capacity.
It is the step everyone skips and it is the reason your number comes out wrong. I skipped it for two years and my 20-minute average was consistently 8–10W high, which meant every sweet-spot session that winter was actually threshold work. I wondered why I was so tired.
- 5-minute easy recovery: Spin easy below 100W for 5 minutes to clear lactate before the test effort begins.
- 20-minute maximal effort: Ride as hard as you can sustain evenly for 20 minutes. Aim for even pacing — do not go out too hard. Record your average power.
- Calculate FTP: Multiply your 20-minute average power by 0.95. For example: 280W × 0.95 = 266W FTP.
How the Ramp Test Alternative Works
A ramp test estimates FTP by increasing resistance by 15–20 Watts every minute until muscular exhaustion. It takes 20–25 minutes total and eliminates the pacing challenge of the 20-minute test.
Your FTP estimate from a ramp test is 75% of your best 1-minute power. For example, a peak 1-minute power of 360W gives an FTP of 360 × 0.75 = 270W.
The ramp test tends to favor riders with a high VO₂ max, while the 20-minute protocol is more accurate for long time trials and endurance racing.
What is a good FTP and Watts per kilogram ratio?
Raw FTP wattage depends heavily on body weight. Cyclists use Watts per kilogram (W/kg) to benchmark power-to-weight ratios across different body types:
| Category | W/kg (Men) | W/kg (Women) | Example FTP @ 70kg |
|---|---|---|---|
| Untrained | < 2.0 | < 1.6 | < 140W |
| Recreational / Cat 5 | 2.0–2.9 | 1.6–2.4 | 140–203W |
| Trained / Cat 4 | 3.0–3.7 | 2.5–3.2 | 210–259W |
| Competitive / Cat 3 | 3.8–4.4 | 3.3–3.9 | 266–308W |
| Well-trained / Cat 2 | 4.5–5.1 | 4.0–4.6 | 315–357W |
| National-level / Cat 1 | 5.2–5.9 | 4.7–5.3 | 364–413W |
| World-class / Pro | > 6.0 | > 5.4 | > 420W |
How to calculate Coggan 7 power training zones
Once your FTP is established, multiply it by the Coggan zone percentages to calibrate your workout intensities:
| Zone | Name | % of FTP | Physiological Adaptation |
|---|---|---|---|
| Z1 | Active Recovery | < 55% | Circulation, fat metabolism |
| Z2 | Endurance | 56–75% | Aerobic base, mitochondrial density |
| Z3 | Tempo | 76–90% | Lactate clearance, glycogen efficiency |
| SS | Sweet Spot | 88–94% | High threshold adaptations with moderate fatigue |
| Z4 | Threshold | 91–105% | Lactate threshold elevation |
| Z5 | VO₂ Max | 106–120% | Maximum aerobic capacity |
| Z6 | Anaerobic | 121–150% | Anaerobic capacity, explosive sprint power |
Frequently Asked Questions About FTP
Why do we multiply 20-minute power by 0.95 for FTP?
A maximal 20-minute effort includes some anaerobic contribution (approximately 5%) that isn’t available during a full 60-minute effort. The 0.95 correction accounts for this difference to establish true aerobic threshold power.
How often should I retest my FTP?
Retest every 6–8 weeks during a structured build phase, or whenever your training zones feel noticeably easy. Significant weight changes also warrant recalculating your W/kg ratio.
Can I estimate FTP from a recent ride without a test?
Yes. If you have clean power meter data, your best 60-minute average power from a hard race or time trial is approximately your FTP. For shorter maximal efforts, apply the appropriate correction factors.
Apply Your FTP — Related Tools & Training Guides
Once your threshold is measured, discover how training load actually works to model fitness and fatigue, or check safe CTL ramp rates for your build phases.
FTP & Watts/kg Calculator
Enter your FTP and weight to instantly generate all 7 Coggan power zones, your W/kg ratio, and competitive category ranking.
Open Calculator →CTL, ATL & TSB Training Load
Now that you know your FTP, learn how to balance fitness and fatigue using the Banister impulse-response model over a 12-week plan.
Read: CTL/ATL/TSB Guide →GPX & FIT Ride Analyzer
Upload your ride files to see elevation profiles, VAM climbing speed, and grade-calibrated power targets for every climb segment.
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