How to Do an FTP Test (20-Minute and Ramp)

Functional Threshold Power — the highest average power in watts a cyclist can sustain for roughly one hour — is the single number that anchors every training zone, every stress score, and every honest answer to the question "am I getting fitter?" Get it wrong, and the rest of your data follows.

This guide covers both established methods for measuring it: the 20-minute test and the ramp test, each with its own warm-up, execution steps, and calculation.

What Is FTP and Why Should You Test It?

Functional Threshold Power was defined by coaches Andrew Coggan and Hunter Allen in Training and Racing with a Power Meter as the highest average power, in watts, a cyclist can sustain for approximately 60 minutes. That definition carries real practical weight.

Every training zone — from Zone 2 endurance work through VO2max intervals — is calculated as a percentage of FTP. Your Training Stress Score (TSS) per ride is derived from how your power compares to it. Set your FTP 20 watts too high or too low, and every zone shifts, every stress score distorts, every fitness trend misleads you.

Two protocols are widely used. The 20-minute test is more demanding and generally considered the gold standard — it more directly approximates hour power. The ramp test removes pacing decisions entirely, making it far more accessible for beginners, though it trades some precision to get there. Both produce a usable FTP number.

How Do You Warm Up Before an FTP Test?

A proper warm-up is not optional. Cold legs produce a false-low FTP, which means zones will be set too conservatively and training will underdeliver.

Follow this 15–20 minute protocol before either test:

1. 10 minutes easy spinning at 50–60% of your estimated FTP.
2. 3 × 1 minute at 100–110% FTP, with 1 minute of easy recovery between each.
3. 5 minutes easy spin to return to baseline.

Pre-test conditions matter just as much. Take a rest day beforehand, avoid heavy meals within 2–3 hours, and use the same trainer setup or course every time — consistent conditions are what make results comparable across retests.

One exception worth noting: the ramp test typically builds its warm-up into the protocol itself. The opening steps are low-wattage by design, so no separate warm-up block is required.

How Do You Do the 20-Minute FTP Test?

Follow these steps in order:

1. Complete the warm-up described above.
2. Ride 5 minutes hard — not all-out, but a strong effort — to open the legs and clear residual fatigue.
3. Rest 5 minutes at an easy pace.
4. Begin your 20-minute all-out effort. Pace it evenly. Target a power you can hold the entire block without fading in the final minutes.
5. Record your average power for the 20-minute segment using your head unit's lap function.

Calculation: Multiply your 20-minute average power by 0.95. This correction factor, established by Coggan and Allen, accounts for the difference between a 20-minute maximal effort and true one-hour power. Example: 280 W average × 0.95 = 266 W FTP.

The most common mistake is starting too hard. Most first-timers surge in minutes one through five and pay for it by minute fifteen. Start conservatively — there is room to push harder in the final five minutes if energy allows.

How Do You Do the Ramp Test?

1. Start at a low wattage — typically 100 W or roughly 50% of your estimated FTP.
2. Increase power by 20 W every 1 minute.
3. Continue until you can no longer hold the target wattage. Failure is defined as cadence dropping below approximately 60 rpm or an inability to sustain the step at all.
4. Record your peak 1-minute power — the highest step you completed.

Calculation: Multiply peak 1-minute power by 0.75. Example: 320 W peak × 0.75 = 240 W FTP. Platforms such as TrainerRoad and Zwift apply their own coefficients automatically, so check whether the app calculates FTP for you.

Pacing decisions are removed entirely here — the protocol specifies exactly what to ride, which is why beginners tend to find it far less daunting. Total time, including the built-in warm-up, runs roughly 20–25 minutes.

One caveat: the 0.75 multiplier is an approximation. Riders with a strong anaerobic capacity may receive a slightly inflated FTP result from a ramp test compared to a 20-minute effort.

How Often Should You Retest FTP?

Joe Friel's periodization guidelines suggest retesting every 6–8 weeks during a structured training block. PlanWatts recommends a slightly tighter window of every 4–6 weeks. The right interval depends on your training phase — base phases tend to produce slower FTP changes than build phases — and your experience level.

Automated FTP detection, available on platforms such as Intervals.icu and TrainerRoad, can estimate changes between formal tests using hard ride data. Think of it as a useful complement, not a replacement for a controlled test under consistent conditions.

Practical cues that signal it is time to retest: workouts feel consistently too easy, power zones no longer match the expected rate of perceived exertion, or a significant training block has just wrapped up and you are returning fresh.