The power meter was invented as long ago as 1988, but it is still treated as a new device by many athletes. Riding with a power meter not only increases your enjoyment of cycling, it also improves your understanding of fitness, provided you are utilizing the features correctly. One of the most useful purposes of a power meter is to determine your functional threshold power (FTP) and, consequently, the related training zones.
Before you can begin to evaluate your performance using power readings, you need to build up a large quantity of data. After training for several weeks with a power meter, you will have gained sufficient information to tell you more about your typical power output and training loads.
The next step is to analyze your power data, using the software that came with the device or independent software that may provide you with a more in-depth analysis. With either option, you should be able to discover your critical power, average power output, and maximum average power output at varying durations.
Establish Your FTP
Now you should be ready to tackle FTP. Cycling Power Lab names three methods to establish your functional threshold power and subsequent training zones. Your choice will depend on your training situation and personal preferences:
- Although functional threshold power is a measure of 60-minute power, it is difficult to test for such a long period of time if you are not racing. The highest accuracy is usually gained from a 20-minute test. Divide your power reading by 1.05 as 20 minutes tends to be around 105 percent of 60-minute power. This method has high accuracy because of the relationship between anaerobic work capacity and sustainable power at increasing durations. You can then use the Monod Model to work out your critical power; the value at 60 minutes is an estimate of your functional threshold power.
- An alternative to completing a 20-minute test is the Monod Critical Power Model. This is completed through two or three tests of shorter duration (either one, five or eight minutes each).
- If you are competing regularly in events of around 25 miles, you should use your reading from your next event.
The Monod Model can also be used to calculate your power training zones. Once you have established these zones, you will be able to train at variable intensities with a higher degree of accuracy. This will help you to target different energy systems and physiological adaptations.
You should use your power meter during all races, as the benefits you will gain are more significant than the slight increase of weight on your bike. This will help you to discover when you hit your limit and why — information that can be used to better develop future training plans.
It's important to periodically retest your functional training power to see how different workouts are affecting your performance, ideally following a recovery week. You may also like to utilize targeted tests such as sprint power, minute power, average power on a specific hill, or others that will help you in a race. Use the tests and data over a long period of time to adjust your training in order to best meet your fitness goals.