How to Measure FTP: Best Testing Methods and Pitfalls
Functional Threshold Power (FTP) is one of the most widely used performance metrics in cycling, but measuring it accurately can be tricky.
There are multiple ways to test FTP, each with advantages and limitations.
In this article, we break down the best testing methods, common pitfalls, and how to ensure reliable results.
Common FTP Testing Methods
1. 20-Minute FTP Test
2. 60-Minute FTP Test (Full Hour Test)
3. Ramp Test
4. Critical Power (CP) Test
5. AI & Smart Trainer Estimations
Common Pitfalls When Testing FTP
How to Ensure Accurate FTP Testing
✅ Choose the right test for your physiology – If you have a strong anaerobic system, the 20-min test may inflate FTP. Consider CP testing instead.
✅ Use consistent conditions – Test in similar temperature, hydration, and fatigue states.
✅ Pace correctly – Especially for time-based tests, a steady effort is key.
✅ Regularly reassess FTP – Fitness changes over time. Test every 6-8 weeks to track progress.
Conclusion
No single FTP test is perfect, but selecting the right method for your physiology and applying it consistently is key to getting reliable data.
In the next article, we’ll explore how to train effectively based on your FTP and optimise your workouts for better performance.
Functional Threshold Power (FTP) is one of the most widely used performance metrics in cycling, but measuring it accurately can be tricky.
There are multiple ways to test FTP, each with advantages and limitations.
In this article, we break down the best testing methods, common pitfalls, and how to ensure reliable results.
Common FTP Testing Methods
1. 20-Minute FTP Test
- How it works: Ride at maximum effort for 20 minutes. Multiply the average power by 0.95 to estimate FTP.
- Pros: Quick and accessible.
- Cons: Requires excellent pacing. Overestimations are common if anaerobic contribution is high.
2. 60-Minute FTP Test (Full Hour Test)
- How it works: Ride at max sustainable power for one hour.
- Pros: Most accurate field test.
- Cons: Mentally and physically demanding. Many cyclists struggle to pace correctly.
3. Ramp Test
- How it works: Power increases every minute until failure. FTP is estimated as ~75% of Maximal Aerobic Power (MAP).
- Pros: Quick and does not require pacing.
- Cons: Estimates may be inaccurate for riders with high anaerobic capacity.
4. Critical Power (CP) Test
- How it works: Requires multiple efforts (e.g., 3-minute and 12-minute) to calculate FTP using a power-duration model.
- Pros: Accounts for anaerobic work (W’), making it more physiologically accurate.
- Cons: More complex and requires multiple maximal efforts.
5. AI & Smart Trainer Estimations
- How it works: Platforms like WKO5, Xert, and Zwift estimate FTP based on ride data.
- Pros: No need for testing if enough data is available.
- Cons: Accuracy depends on data quality and training history.
Common Pitfalls When Testing FTP
- Poor Pacing 🔥
- Going too hard at the start leads to burnout.
- A well-paced test should have a steady power output.
- Fatigue Before Testing 💤
- Testing after a hard training block leads to lower values.
- Ensure fresh legs for accurate results.
- Insufficient Warm-Up 🚀
- Skipping warm-up causes lower power output.
- A proper warm-up should include progressive efforts.
- Environmental Factors 🌡️
- Heat, altitude, and hydration affect FTP results.
- Always test under similar conditions.
- Test Selection Mismatch 📊
- Ramp tests often overestimate FTP for anaerobically strong riders.
- Long tests underestimate for those with low fatigue resistance.
How to Ensure Accurate FTP Testing
✅ Choose the right test for your physiology – If you have a strong anaerobic system, the 20-min test may inflate FTP. Consider CP testing instead.
✅ Use consistent conditions – Test in similar temperature, hydration, and fatigue states.
✅ Pace correctly – Especially for time-based tests, a steady effort is key.
✅ Regularly reassess FTP – Fitness changes over time. Test every 6-8 weeks to track progress.
Conclusion
No single FTP test is perfect, but selecting the right method for your physiology and applying it consistently is key to getting reliable data.
In the next article, we’ll explore how to train effectively based on your FTP and optimise your workouts for better performance.
