How to Determine Your Functional Threshold Power

Wisconsin Marathon 2020

As athletes, we are always trying to get better. Whether than means improving the number of points scored in a soccer game or obtaining a PR (personal record) during a triathlon, getting better is the ultimate goal!

When it comes to cycling, we like to pedal harder, pedal faster, and work hard for that personal record through both indoor and outdoor training. While we can determine how much we’ve improved by actually obtaining a PR, there are also field test methods that will show you where you are at in your training versus where you want to be. This is where Functional Threshold Power comes in.

FTP also known as Functional Threshold Power is something that every cyclist has. Whether you’re a veteran rider or new to the sport, each cyclist has their own personal Functional Threshold Power.

So what exactly is Functional Threshold Power? Functional Threshold Power measures how long you can sustain maximum power for one hour. We’re not talking intervals here. We’re talking constant maximum power straight through 60 minutes without a decrease in effort or fatigue. Figuring out your own FTP enables you to track your progress, analyze your pacing strategies, and ideally work to increase your Functional Threshold Power.

So, now that we understand what Functional Threshold Power is, let’s talk how to determine your personal Functional Threshold Power.

Critical Power 20 Test or CP20

This go-to Functional Threshold Power is a favorite among athletes and trainers. During this field test you will use a cycling power meter to measure measure average power output for 20 minutes. This can be done on an indoor trainer or outdoors as well. If you choose to take the Critical Power 20 Test outdoors, you ideally would want to be riding on a consistent flat road. Try to avoid going up or down inclines so you can maintain one “all out” pace during the entire 20 minute period.

Once you know your average power for 20 minutes (for example 250 watts) you can multiply it by 95% to estimate your FTP.

For example: If your CP20 power output is 250 watts, a good estimation of your FTP would be 237.5 watts.

To ensure testing accuracy, it’s typically a good idea to redo this test several times. Throughout the year, keep a log with your Functional Threshold Power results. This will allow you to determine test improvements.

Knowledge is power. Knowing your Functional Threshold Power is important if you want to improve your overall cycling efforts. By obtaining this number and working hard to improve it through training, you’ll want to push yourself and increase pace in situations where you may not have been able to do otherwise. Find out what your Functional Threshold Power and work hard towards improving that number!

If you need help in determining your Functional Threshold Power, please contact me.

Train Right, Tri Right,

Coach MJ


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