FTP Testing Guide: How to Find Your Cycling Threshold

What Is FTP and Why Does It Matter?

Functional Threshold Power (FTP) is the highest average power, measured in watts, that you can sustain for approximately one hour. It represents the boundary between efforts you can maintain aerobically and efforts that accumulate fatigue so rapidly that you are forced to stop.

FTP is the single most important number in power-based cycling training. Every training zone, every workout target, and every metric like TSS (Training Stress Score), IF (Intensity Factor), and Normalized Power is calculated relative to your FTP. Get it wrong and your entire training structure is miscalibrated.

An undertested FTP means your zones are too easy. You will train comfortably but not improve as fast as you could. An overtested FTP means your zones are too hard. Your "easy" rides will actually be moderate, your "threshold" efforts will be unsustainable, and you will accumulate fatigue without the intended training stimulus.

Testing Protocol #1: The 20-Minute Test

The 20-minute test is the most widely used FTP test, popularized by coach Andrew Coggan and the TrainingPeaks ecosystem.

Protocol

1. Warm up for 20 minutes. Include some progressive efforts: 5 minutes easy, 5 minutes moderate, 3x1-minute hard efforts with 1-minute recovery, then 5 minutes easy.
2. 5-minute blowout. Ride as hard as you can for 5 minutes. This is not part of the FTP calculation -- it depletes your anaerobic reserves so the 20-minute effort is more aerobically representative.
3. 10 minutes easy recovery.
4. 20 minutes all-out. Ride as hard as you can sustain for the full 20 minutes. Start conservatively. If you go out too hard, you will fade and the result will not be accurate.
5. Cool down for 10 to 15 minutes.

Calculating FTP

Take your average power for the 20-minute effort and multiply by 0.95. The 5 percent reduction accounts for the difference between a 20-minute effort and a 60-minute effort.

Example: If your average power for the 20 minutes was 260 watts, your estimated FTP is 260 x 0.95 = 247 watts.

Pros and Cons

Pros: Well-established protocol with years of research. Relatively straightforward. Produces reliable results when executed correctly.

Cons: Pacing is difficult. If you go out 10 watts too hard, you might blow up at minute 14 and the test is ruined. The 0.95 multiplier is an average -- some athletes can sustain a much higher fraction of their 20-minute power for an hour, while others cannot.

Testing Protocol #2: The Ramp Test

The ramp test has become popular because it removes the pacing challenge entirely. You simply ride at increasing intensity until you cannot continue.

Protocol

1. Warm up for 10 minutes at easy intensity.
2. Begin the ramp. Starting at a low wattage (usually 100 watts), increase by 20 watts every minute. Some protocols use 25 watts per minute.
3. Continue until failure. Ride until you physically cannot maintain the target power for the current step. This typically takes 15 to 25 minutes depending on fitness.
4. Cool down for 10 minutes.

Calculating FTP

Take 75 percent of the highest one-minute average power you achieved during the ramp.

Example: If the last full minute you completed was at 340 watts, your estimated FTP is 340 x 0.75 = 255 watts.

Pros and Cons

Pros: No pacing required -- you just ride until you stop. Shorter and less psychologically daunting than a 20-minute effort. Easy to repeat consistently. Great for indoor trainers with ERG mode.

Cons: Heavily influenced by anaerobic capacity. Athletes with a strong anaerobic system may get an inflated FTP estimate because they can push through the final minutes on anaerobic reserves. The 0.75 multiplier has the same individual variation problem as the 0.95 multiplier in the 20-minute test.

Testing Protocol #3: The 2x8-Minute Test

The 2x8-minute test uses two shorter efforts separated by recovery. It is less mentally taxing than a single 20-minute effort and can produce accurate results.

Protocol

1. Warm up for 15 to 20 minutes with progressive intensity.
2. 8 minutes all-out. Ride as hard as you can sustain for 8 minutes.
3. 10 minutes easy recovery.
4. 8 minutes all-out. Repeat the effort.
5. Cool down for 10 minutes.

Calculating FTP

Average the power from both 8-minute efforts, then multiply by 0.90.

Example: If your two efforts averaged 275 and 265 watts, the mean is 270 watts. FTP estimate: 270 x 0.90 = 243 watts.

Pros and Cons

Pros: Shorter individual efforts are easier to pace. Two efforts provide a consistency check. Less psychologically intimidating.

Cons: Two efforts mean two chances for things to go wrong. If the second effort is much weaker than the first, you paced poorly. The 0.90 correction factor adds another layer of estimation.

Which Test Should You Choose?

For most amateur cyclists, the ramp test is the best starting point. It is simple, repeatable, and removes the biggest source of error (pacing). Just be aware that if you are an athlete with exceptional anaerobic capacity -- if you can sprint hard but struggle with sustained efforts -- the ramp test may overestimate your FTP.

The 20-minute test is the gold standard when executed properly. If you have done it before and know how to pace a 20-minute effort, it produces the most reliable results.

The 2x8-minute test is a good middle ground for athletes who find 20 minutes mentally overwhelming.

Regardless of which test you choose, consistency matters more than protocol. Use the same test every time so you can track changes. An FTP derived from a ramp test is not directly comparable to one from a 20-minute test.

Setting Power Zones

Once you have your FTP, set your training zones. The most common zone system uses seven zones:

Zone	Name	% of FTP	Purpose
1	Active Recovery	< 55%	Easy spinning, recovery rides
2	Endurance	56-75%	Aerobic base building, long rides
3	Tempo	76-90%	"Comfortably hard," group ride pace
4	Threshold	91-105%	FTP intervals, time trial pace
5	VO2max	106-120%	3-8 minute intervals
6	Anaerobic	121-150%	30s-2 minute max efforts
7	Neuromuscular	> 150%	Sprints, < 30 seconds

Enter your FTP into your Garmin head unit to get real-time zone display during rides. On most Garmin cycling computers, go to Settings > User Profile > Power Zones and enter your FTP value. The zones will be calculated automatically.

Key Metrics Derived from FTP

Normalized Power (NP)

NP is an adjusted average power that accounts for the variability of your ride. A ride with lots of surges and coasting (like a group ride) will have a higher NP than average power because the hard surges cost more physiologically than steady riding.

Intensity Factor (IF)

IF equals NP divided by FTP. An IF of 1.0 means you rode at your threshold. An IF of 0.70 means an endurance-pace ride. An IF above 1.05 for an extended effort usually means your FTP is set too low.

Training Stress Score (TSS)

TSS combines intensity and duration into a single training load number. TSS = (duration in seconds x NP x IF) / (FTP x 3600) x 100. A one-hour ride at exactly FTP produces a TSS of 100.

Daily TSS guidelines:

• Under 150: Low. Recoverable by next day.
• 150-300: Medium. Some residual fatigue the next day.
• 300-450: High. Two days to fully recover.
• Over 450: Epic. Multiple days of recovery needed.

Tracking FTP Over Time

Retest your FTP every six to eight weeks. More frequently and the changes will be too small to be meaningful. Less frequently and your training zones may be stale.

Track your FTP history alongside training volume and key events. You will start to see what training approaches produce the biggest gains. Most athletes see the largest FTP improvements from consistent threshold work combined with a solid base of zone 2 riding.

Expect FTP gains to slow as you get fitter. A beginner might gain 20 to 30 watts in the first few months. An experienced rider might gain 5 to 10 watts per year. At the upper levels, every watt is hard-earned.

Gneta tracks your FTP alongside your complete Garmin training data, giving you power metrics like NP, TSS, and IF for every ride. When combined with recovery data like body battery and HRV, you can see not just how hard you rode, but how your body responded -- and when you are ready for your next key session.