By BikeRadar

Published: Friday, 11 February 2022 at 12:00 am


FTP stands for Functional Threshold Power, which is defined as the highest average power you can sustain for approximately an hour, measured in watts.

FTP is one of the most common training metrics used in cycling and is frequently used by coaches as a benchmark metric and to determine training zones when using a power meter, while the latest training apps also use FTP to set workouts and training plans when using a smart trainer.

In this guide, we’ll look at how to determine your FTP, what you can do with that number, and how to improve your FTP. We’ll also consider why FTP might not always be the best number to use to guide your training effectively.

How to determine your FTP

Indoor cycling apps such as TrainerRoad, Wahoo SYSTM and Zwift use Functional Threshold Power to calibrate workout intensities. For example, Zwift may call for three-minute intervals at 120 per cent of your FTP, with two-minute recoveries in between.

Cycling coaches use FTP in the same way – to measure progress and to personalise specific training intensities. This is the same process whether working with WorldTour team riders or keen amateurs.

The previous standard, lactate threshold, involved measuring blood lactate every few minutes while ramping up intensity on a trainer.

"Zwift
Zwift and a number of other training apps use FTP to create personalised workouts on the indoor trainer.
Ben Delaney / Immediate Media

Dr Andrew Coggan, co-author of Training and Racing with a Power Meter, created the FTP standard as a more practical approach. In functionality, training to lactate threshold and FTP are very similar.

“FTP has become the gold standard,” says Scott Moninger, a former professional cyclist and coach for Velocious Cycling Adventures. “Whereas a few years ago you had to go into a lab, now you can get that number with a power meter and a 20-minute field test.

“In a perfect world, I’d get a cyclist to do a 60-minute time trial, but I can’t ask people to do that,” Moninger says. “Even if you removed the realities of traffic and stoplights, a 60-minute time trial is very difficult to do.”

So Moninger and most others use a 20-minute field test with a power meter.

How to find your FTP with a 20-minute test

"TrainerRoad
An all-out 20-minute ride is the benchmark test for finding your FTP.
TrainerRoad

To measure your FTP, you need a bike with a power meter or a smart trainer with an integrated power meter. A bike with a power meter is ideal because you are generally able to generate more power outside than when you’re on a fixed bike inside.

The key, however, is to make the test repeatable, so you have consistent results from one test to the next.

After a good warm-up, including one or two hard efforts of four to five minutes, ride as hard as is sustainable for 20 minutes.

Moninger recommends finding a road grade of anywhere between 2 and 4 per cent if possible because this will engage more of your glutes and back muscles and result in the best possible power.

“I see differences of between five and 15 watts, depending on the person,” Moninger says. “It’s the same with a trainer, and it’s the same reason power on a time-trial bike is lower, even for the best TT riders in the world.”

Once home, go back and look at your average power for that 20-minute effort. You can use Garmin Connect, Strava, TrainingPeaks or Golden Cheetah to do this.

You can also just use your Garmin, Wahoo or any other compatible bike computer – just remember to start and stop a lap for your 20-minute effort.

Once you have your average 20-minute power, subtract 5 per cent and you have your FTP.

What can you do with your FTP?