What is FTP and why it matters for cyclists

What Functional Threshold Power means, how to test it and how to improve it

FTP stands for Functional Threshold Power, which is commonly defined as the highest average power you can sustain for approximately an hour, measured in watts. FTP is often used to determine training zones when using a power meter and to measure improvement.


How to determine your FTP

Training programs such as TrainerRoad, The Sufferfest and Zwift (with the Workout option) use FTP to calibrate workout intensities. For example, the programs may call for three-minute intervals at 120 percent of your FTP, with two-minute recoveries in between.

Coaches use FTP in the same way — to measure progress and to personalize specific training intensities. This is the same process whether you’re working with Team Sky riders or age-group amateurs.

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

Jack and Joe recently went to The University of Bath to determine their FTP, training zones and VO2 max

“FTP has become the gold standard,” says Scott Moninger, a Peaks Coaching Group master coach who raced as a professional for 17 years. “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.”

Zwift now has a Workout feature that is calibrated on your FTP
Zwift now has a Workout feature that is calibrated on your FTP
Ben Delaney / Immediate Media

“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

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 meter is ideal because you are able to generate more power outside than when you’re on a fixed bike inside.

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 percent if possible, as 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 or other head unit — just remember to start and stop a lap for your 20-minute effort.

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

What can you do with your FTP

Learn what effort levels are sustainable for different durations

The first time you do a 20-minute test, you will probably start out too hard and see your wattage number gradually fade — even if the effort feels the same, start to finish. This exemplifies why it’s helpful to have a meter quantify your power production instead of just relying on feel.

The more you ride with a power meter, the more you will understand your abilities. Starting a 20-minute climb? Let your buddies blow themselves up going hard for the first couple of minutes while you carefully meter out your effort, riding at your FTP.

Chris Froome gets a lot of flack for staring at his computer during critical Tour de France stages as he monitors his effort. But you know what? He rode within his capabilities — and he’s won the Tour four times.

Measure your improvement

How do you know if you’re getting fitter and faster? Because you beat your training buddy up a hill? Or because you bettered your time at your local time trial? These are useful, but not exactly scientific. Your buddy could have been hungover and the TT might have had a screaming tail wind. Measuring your FTP is analogous to standing on a bathroom scale — that number ain’t gonna lie.

Moninger recommends testing your FTP every four to six weeks during the season.

How your FTP compares to another rider’s is irrelevant. The highest FTP is not what wins a race. The highest power-to-weight ratio will likely win a hill climb and the highest power-to-drag ratio will likely win a flat time trial. But the FTP number in and of itself is not a comparative metric — it is your personal number for specific training.

Speaking of that bathroom scale, if your FTP is going up and your weight is going down, you are going to go faster. Period.

TrainerRoad is a power-based training app with workouts that all revolve around your FTP — and helping you improve that number
TrainerRoad is a power-based training app with workouts that all revolve around your FTP — and helping you improve that number
Ben Delaney / Immediate Media

Calibrate your training zones

One of the first things training software programs will prompt you for is your FTP. Plug in this number and the program will do the rest, whether this is TrainerRoad, Zwift or something else. Many of these programs have built-in tests to help you measure your FTP.

If you are using a training plan from a book, a magazine, a coach or elsewhere, it will prescribe training by zones. Usually there are seven zones (depending on the coach’s or company’s particular philosophy). For training with power, these are based on your FTP and are often determined like this:

Training zones for cyclists explained

Zone 1  Active recovery  <55% of FTP
Zone 2  Endurance  56–75% of FTP
Zone 3  Tempo  76–90% of FTP
Zone 4  Threshold  91–105% of FTP
Zone 5  VO2 Max  106–120% of FTP
Zone 6  Anaerobic capacity  121+% of FTP
Zone 7  Neuromuscular power  FTP N/A

When you hear people talk about doing a tempo ride, or an endurance ride, what they are talking about is training in those specific zones.

Training zones can be just as important for easy training days as hard ones. Cyclists are often guilty of going too hard on easy days and are then unable to go as hard as needed on very hard days.

How to improve your FTP

In short, train. Instead of just riding along and hoping for the best, spend time riding in zones three and four. Cyclists will naturally settle into riding at endurance pace, which is helpful for building a solid base. But the biggest gains for FTP come by pushing near or above that threshold.

Frank Overton, founder and head coach at FasCat Coaching, has, for a decade now, been a big proponent of ‘sweet spot’ training as a way to raise FTP and generally be more productive with your training time. He and other coaches define ‘sweet spot’ as an overlap between the top-end of Tempo and the low-end of Threshold. (How to Sweet Spot — by Frank Overton)

Overton recommends working sweetspot training into group rides or climbing efforts, but for those who want specific intervals he suggests:

  • 4 x 15min between 84 and 97 percent of FTP; 10 minutes easy pedaling between efforts
  • 2 x 20min between 84 and 97 percent of FTP; five minutes easy pedaling between efforts
Article last updated 19th March 2019