Functional Threshold Power Test
“The purpose of this initial test is to do a ride where you can average the highest watts possible for a substantial period of time. Be sure to do the same warm-up, and to use the same intensity in your warm-up, each time you do the test. The warm-up and recovery intervals throughout the test should be at about 65 percent of your functional threshold power, which would be Endurance pace. After the three fast pedaling intervals, the true warm-up begins.
When you begin the 5-minute all-out effort, punch it and hold it! Start at a high pace, but not so high that you die at the end. You should have a little in reserve to kick it to the finish line in the last minute. The goal of this first part is twofold: first, to “open” up the legs for the rest of the effort, and second, to capture your ability to produce watts in what is called VO2max power, or Level 5 (discussed later in this chapter). Your next effort is more likely to be truly representative of your FTP.
For the 20-minute time trial, ride on a road that is fairly flat, allowing a strong, steady effort for the entire 20 minutes. Do not start out too hard! Get up to speed and then try to hold that speed. If you have never done one of these efforts before, try this on a steady climb or into a slight headwind, where you are forced to ride at a maximum effort for the entire 20 minutes. Your goal is to produce the highest average wattage over the entire period. If you suddenly run out of energy, you will not be able to produce your true maximal steady-state power. It is always better to be a little under what you believe to be your FTP for the first 2 minutes, build speed, and then ride at your maximum level in the last 3 minutes.
Finish the ride at an easy pace.
Once this test is over and you have downloaded the data, you will need to figure out what your average power was for the entire 20-minute effort. Then you will take this number and subtract 5 percent from it. The number that results will be your functional threshold wattage value. (Hold on to this number, as we will come back to it later in this chapter.) So, for example, if you average 305 watts for the 20-minute time trial, you would calculate that 305 × 0.05 = 15.25, and 305 – 15.25 = 290. Thus, your functional threshold power is 290 watts.
The reason for subtracting 5 percent of the watts from your 20-minute test is that FTP is defined as the highest average wattage or power that you can maintain for 60 minutes. Because some athletes have a hard time focusing for 60 minutes on a maximal effort, and those who can learn very quickly that a 60-minute time trial is not that much fun, we have found that 20 minutes is more realistic in terms of getting athletes to do more regular and higher-quality tests. Since 20 minutes is a shorter time period, it incorporates more of the athlete’s anaerobic capacity, however, and this skews the wattage data by about 5 percent over a 60-minute effort. By subtracting that 5 percent, you will come up with a wattage number that would be very close to your 60-minute power measure.
One goal of any training program is to increase power at threshold (FTP), and how often threshold power changes significantly depends in part on an individual’s training history and habits. For example, someone who is just beginning to cycle or returning to cycling after a long break may see large and rapid changes in threshold power at first, whereas an experienced rider who has been training for many years, or an athlete who maintains a high level of conditioning year-round, will probably experience much less variation. In general, assessing FTP four to six times a year (e.g., in the middle of winter training, near the start of serious outdoor training as a baseline, partway through the pre-competition period to track improvement, a couple of times during the season to determine peak fitness, and finally, after your peak fitness is over for the season, to determine how far you have “fallen”) is probably sufficient.”
Excerpt From: Hunter Allen & Andy Coggan PhD. “Training and Racing with a Power Meter, 2nd Ed.” iBooks.
As one of my New Year’s Resolutions, I have resolved to re-read some of the best and most respected books on the subject of fitness, training, and exercise physiology.
I’m starting this re-education with a book that many in the cycling world consider the “Bible” of training with a power meter, Training and Racing with a Power Meter, 2nd Ed. – Hunter Allen & Andy Coggan PhD.
As I read I’ll share excerpts that I believe are pertinent in the world of indoor cycling and the ever growing use of power meters and group display.