FTP
Functional Threshold Power
FTP (Functional Threshold Power) is the highest power output a cyclist can sustain for approximately one hour. Learn what FTP means, how it's measured, and why it matters for cycling training.
Quick Answer
FTP — (Functional Threshold Power) is the highest average power output, measured in watts, that a cyclist can sustain for approximately one hour. It represents the boundary between sustainable and unsustainable exercise intensity.
What Does FTP Mean?
FTP stands for Functional Threshold Power. It's a key metric in cycling that measures your sustainable power output over a prolonged period—specifically, about one hour of all-out effort.
In physiological terms, FTP closely corresponds to your lactate threshold—the exercise intensity at which lactate production exceeds your body's ability to clear it. Below this threshold, you can ride for hours. Above it, fatigue accumulates rapidly.
For a comprehensive overview, see our Complete FTP Guide.
Why FTP Matters
FTP serves as the foundation for structured cycling training:
| Use Case | How FTP Helps |
|---|---|
| Training Zones | All power zones are calculated as percentages of FTP |
| Progress Tracking | Compare FTP over time to measure fitness gains |
| Race Pacing | Know what power output you can sustain for a given duration |
| Workout Prescription | Coaches use FTP to set interval intensities |
FTP also helps you calculate your Training Stress Score (TSS), which quantifies how hard each workout is relative to your fitness level.
How FTP is Measured
FTP is measured in watts (W). Use our FTP Calculator to find your FTP, or learn more about the different FTP testing protocols.
The 20-Minute Test
The most popular method. Ride as hard as possible for 20 minutes, then multiply your average power by 0.95 to estimate your hour power.
Use our 20-Minute FTP Calculator to process your test results.
Formula:
FTP = 20-minute average power × 0.95
Example: If you average 280W for 20 minutes:
FTP = 280 × 0.95 = 266W
The 5-Minute Test
A shorter alternative. Multiply your 5-minute max power by 0.75.
Use our 5-Minute FTP Calculator for quick estimates.
The Ramp Test
Progressive power increases until failure. Take 75% of your final completed minute's average power. This is the default test on Zwift.
FTP Training Zones
Once you know your FTP, you can calculate your training zones. Learn more about how to use FTP zones effectively.
| Zone | Name | % of FTP | Purpose |
|---|---|---|---|
| 1 | Active Recovery | < 55% | Easy spinning, recovery |
| 2 | Endurance | 56-75% | Base building, long rides |
| 3 | Tempo | 76-90% | Muscular endurance |
| 4 | Threshold | 91-105% | FTP improvement |
| 5 | VO2 Max | 106-120% | Aerobic capacity |
| 6 | Anaerobic | 121-150% | Short, intense efforts |
| 7 | Neuromuscular | Max | Sprints |
The Sweet Spot zone (88-94% FTP) is particularly effective for improving FTP with manageable fatigue. Learn more about Sweet Spot Training.
Power-to-Weight Ratio (W/kg)
For climbing and overall cycling ability, your watts per kilogram (W/kg) matters more than absolute watts. Use our Watts Per Kilo Calculator to find yours.
| W/kg | Level |
|---|---|
| 2.5-3.0 | Recreational cyclist |
| 3.0-3.5 | Enthusiast |
| 3.5-4.0 | Competitive amateur |
| 4.0-4.5 | Regional racer |
| 4.5-5.0 | National level |
| 5.0+ | Professional |
For detailed benchmarks, see our FTP Chart by Watts Per Kg and FTP by Age.
Formula:
W/kg = FTP (watts) ÷ Body weight (kg)
How to Improve FTP
Key training approaches to increase your FTP:
- Threshold Intervals – 2×20 minutes at 95-100% FTP
- Sweet Spot Training – Longer efforts at 88-94% FTP
- VO2 Max Work – Shorter, harder intervals to raise your aerobic ceiling
- Consistent Volume – Build base fitness with endurance rides
Most cyclists can improve FTP by 5-15% per year with structured training. Check out our Best FTP Workouts for specific sessions, or follow our 8-Week FTP Training Plan.
Common Questions
How often should I test FTP?
Every 4-8 weeks during training phases. More frequent testing adds fatigue without useful data. See How to Test Your FTP for best practices.
Is indoor FTP different from outdoor?
Often yes. Many cyclists have a 5-15% lower FTP indoors due to heat, psychology, and lack of terrain variation. Learn more in our Zwift FTP Test Guide.
What's a good FTP for beginners?
There's no universal answer—FTP depends on age, gender, weight, and training background. Focus on improving your own FTP rather than comparing to others. For reference, see What is a Good FTP? and Average Cycling FTP.
Why did my FTP drop?
FTP can decrease due to fatigue, illness, detraining, or poor test conditions. Read our article on Why FTP Drops and How to Fix It.