Zwift FTP Test Guide - Ramp Test vs 20-Minute Test
Master FTP testing in Zwift. Compare the ramp test and 20-minute test protocols, learn which is best for you, and get tips for accurate indoor results.
Zwift has made FTP testing more accessible than ever—but which test should you choose? The platform offers several options, each with distinct advantages. Here's how to get the most accurate results from your indoor testing.
Zwift FTP Test Options
Ramp Test
The most popular option. Power increases every minute until you can't continue.
How it works:
- Start at low power (~100W)
- Power increases 20W every minute
- Continue until failure
- FTP = 75% of your best 1-minute power
Duration: 15-25 minutes depending on fitness
Use our Zwift FTP Calculator to process ramp test results.
20-Minute Test
The classic protocol adapted for Zwift.
How it works:
- Structured warm-up
- 5-minute all-out effort (clears legs)
- Recovery
- 20-minute max effort
- FTP = 95% of 20-minute average
Duration: ~60 minutes total
Use our 20-Minute FTP Calculator for results.
Shorter Test
Zwift also offers a combined shorter test with 5-minute and 1-minute efforts. Less commonly used but available.
Ramp Test vs 20-Minute: Which to Choose?
| Factor | Ramp Test | 20-Minute Test |
|---|---|---|
| Duration | 15-20 min | 60 min |
| Pacing decisions | None | Critical |
| Mental demand | Moderate | High |
| Reproducibility | Excellent | Good |
| Accuracy for anaerobic types | May overestimate | More accurate |
| Accuracy for diesel types | May underestimate | More accurate |
Choose the Ramp Test If:
- You're new to FTP testing
- Pacing a 20-minute effort stresses you
- You want quick, reproducible results
- You test frequently to track progress
- You have limited time
Choose the 20-Minute Test If:
- You have racing experience
- You can pace sustained efforts accurately
- You want the most accurate result
- Your racing involves long threshold efforts
- You're "diesel" (strong endurance, weaker short power)
Ramp Test Deep Dive
The Protocol
Zwift's standard ramp test:
- Starts at 100W
- Increases 20W per minute
- ERG mode holds power automatically
- Continue until you literally cannot turn the pedals
Calculating FTP
FTP = Last Completed Minute × 0.75
If you completed 350W for the full minute but failed at 370W:
- FTP = 350 × 0.75 = 262W
Some variations use 75% of your peak 1-minute power (which may be higher if you partially completed the last step).
Advantages
No pacing required: ERG mode handles power. You just pedal until you can't.
Highly reproducible: Same protocol every time makes comparison easy.
Quick: Total workout under 30 minutes including warm-up.
Less mentally demanding: No 20-minute suffering—just one minute at a time.
Disadvantages
May overestimate for anaerobic athletes: If you have strong 1-minute power relative to threshold, the 75% calculation overestimates FTP.
May underestimate for endurance athletes: If you're a "diesel" with strong sustained power but weaker short power, ramp tests underestimate FTP.
Doesn't test pacing: Racing and time trials require sustained effort pacing—the ramp test doesn't develop this skill.
Execution Tips
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Complete warm-up: The built-in warm-up is minimal. Add 10 minutes of easy spinning before.
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High cadence early: Start around 90+ rpm. You'll naturally drop as it gets hard.
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Stay seated: Standing changes the effort type and may lead to earlier failure.
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Go until complete failure: This isn't "comfortable hard"—it's "can't turn pedals anymore."
-
Consistent setup: Same fan, same room temperature, same time of day for comparison.
20-Minute Test Deep Dive
The Protocol
Zwift's FTP Test (Long) includes:
- 10-min warm-up
- 3 × 1-min high cadence
- 5-min recovery
- 5-min all-out (to pre-fatigue)
- 10-min recovery
- 20-min max sustainable power
- Cool-down
Calculating FTP
FTP = 20-minute Average × 0.95
If you averaged 280W for 20 minutes:
- FTP = 280 × 0.95 = 266W
Advantages
Most accurate for most athletes: The sustained effort matches what FTP represents.
Tests pacing ability: Essential skill for racing and time trials.
Familiar to experienced cyclists: Standard outdoor test adapted for indoor.
Disadvantages
Requires pacing experience: Poor pacing leads to inaccurate results.
Mentally demanding: 20 minutes of maximal effort is psychologically tough.
Takes longer: Full test is 60+ minutes.
Variable results: Pacing errors create inconsistency between tests.
Execution Tips
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Nail the pacing: Start at 95% of your expected power. Build only if feeling strong.
-
Use ERG sparingly: Some prefer ERG at target power; others prefer free ride. Test both.
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Ignore heart rate early: It will climb. Focus on power and perceived effort.
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Negative split if possible: Better to finish fast than blow up.
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Complete the 5-minute effort: The pre-fatigue effort is crucial for accurate 20-minute power.
Common Zwift Testing Mistakes
Inadequate Cooling
Indoor FTP is often lower than outdoor due to heat buildup. Use multiple fans—your body generates 75% of energy as heat.
Solution: Fan directly on torso and face. Room temperature below 20°C if possible.
ERG Mode Issues
ERG mode can cause "death spiral"—as you fatigue, cadence drops, ERG increases resistance, making it even harder.
Solution: Maintain 85+ rpm throughout. If cadence drops below 75, shift to an easier gear (even in ERG) or switch to free ride.
Trainer Not Calibrated
Uncalibrated trainers give inconsistent power readings.
Solution: Calibrate before every test. Warm up the trainer for 10+ minutes first.
Testing Too Frequently
Weekly testing adds fatigue without useful data.
Solution: Test every 4-8 weeks during build phases.
Poor Warm-Up
Cold muscles and cardiovascular system can't perform optimally.
Solution: Add 10-15 minutes easy spinning beyond Zwift's built-in warm-up.
Setting Up for Success
Room Preparation
- Temperature: Below 20°C (68°F) if possible
- Fans: At least two, aimed at face and torso
- Ventilation: Open windows or doors
Trainer Setup
- Calibrate: Follow manufacturer instructions
- Firm surface: No carpet wobble
- Tire pressure: Consistent between tests
Personal Preparation
- Rested: Easy day before, good sleep
- Fueled: Normal meal 2-3 hours before
- Caffeine: If you normally use it
- Motivation: Choose a time when you're mentally ready
Zwift Settings
- Trainer difficulty: Set and leave consistent
- ERG mode: Understand when to use it
- Display: Power (3-sec average) visible
Interpreting Your Results
FTP Feels Too High
If workouts based on new FTP feel impossible:
- Test may have been influenced by caffeine or exceptional motivation
- Ramp test may have overestimated (anaerobic athlete)
- Reduce FTP by 2-5% and reassess
FTP Feels Too Low
If workouts feel too easy:
- Poor pacing on 20-minute test
- Ramp test may have underestimated (endurance athlete)
- Increase FTP by 2-5% and reassess
Indoor vs Outdoor Discrepancy
Many riders have different indoor and outdoor FTPs:
- Indoor often 5-15% lower due to heat
- Some riders perform better with road feel
- Psychological factors affect performance
Solution: Maintain separate indoor and outdoor FTPs if you train in both environments.
After Your Test
Once you have your FTP:
- Calculate zones: Use Power Zones Calculator
- Update Zwift: Change FTP in settings for accurate workout targets
- Plan training: Start an FTP training plan
- Track progress: Monitor TSS over time
- Schedule next test: 4-8 weeks out
Related Tools
- ZWO to FIT Converter - Use Zwift workouts on your Garmin
- FIT to ZWO Converter - Recreate rides as Zwift workouts
Related Articles
- Complete FTP Guide - FTP fundamentals
- How to Find Your FTP - Find FTP on Strava, Garmin, Peloton
- How to Test Your FTP - All test protocols
- FTP Chart by W/kg - Compare your result
- What is a Good FTP? - Goal-based benchmarks
- Best FTP Workouts - Training sessions
- How to Improve FTP - Training strategies