Before going into detail, let’s introduce the concept of FTP. The “Functional Threshold Power” test, better known as FTP or in Spanish “Functional Power Threshold” (UPF), is a performance test that determines the functional power threshold, that is, the maximum average power that you could carry during a specific time interval.
How do I calculate my FTP value?
There are a wide variety of tests used to measure FTP at different intensities and time periods. We will briefly discuss ICG® testing and then delve into a more generic Power testing protocol.
At ICG® we have 2 tests with Coach By Color® to accurately measure your FTP. These tests are integrated into the console of the bikes. On the one hand, the 5-minute FTP test allows all users in the group to start and finish the test together. In addition, this test can be done in a “normal” class format, with a warm-up, preparation and cool-down section. If you are not sure how you will feel giving your maximum effort for 5 minutes, think about your fastest short distance race (one kilometer).
The second test we use is the FTP ramp test. This is a progressive test and allows people to learn about power values while they are doing the test. The test starts by asking for just 75 watts. The rider reaches that figure with a combination of speed and leg endurance. The rider must then maintain those results for 4 minutes, at which point the target watts are increased by 25. The target power will increase by a further 25 watts every 4 minutes thereafter until the rider can no longer maintain the target, at which point the test is ended and a result is given. All riders start together, but finish at different times. This test is initially easy, but it gets harder in the last 1-2 ramps as they are likely to be above their functional threshold.
These tests are perfect for measuring your power, but you may have read about 20-minute FTP tests, better known as CP20, on some cycling forum.
CP20 Test
The CP20 test involves a 20-minute all-out effort and is a true test of power, mental toughness and resistance to fatigue. So how do you do it? Here’s a simple guide.
As you would expect with any kind of maximal effort, the body needs to be warm, so the warm-up for the CP20 is quite extensive and time-consuming. In fact, you cycle for around 30 minutes before you do the stress test. The long, progressive warm-up ensures that all systems are ready for action, we have heat in our muscles to prevent injury and we have exhausted the anaerobic systems a little so they have less impact on the result. If you have an hour, then it’s like this…
- 10 minutes of moderately easy riding at a cadence of around 90 RPM.
- 3 cycles of 1 minute at over 100 RPM with 1 minute recoveries.
- 5 minutes of moderately easy riding at a cadence of around 90 RPM
- 5 minutes of maximum effort at the preferred cadence
- 10 minutes of moderately easy riding at a cadence of around 90 RPM
- 20-minute time trial: full effort for the entire duration in steady state.
- 5 minutes of progressive cooling
- Get off the bike and then do some stretches, lowering your heart rate.
The average watts sustained over your 20-minute time trial (TT) effort is the starting point for calculating FTP. Take the average amount of watts sustained over that effort and reduce it by 5%.
For example:
- Average Watts for TT effort = 354 Watts
- 354 watts x 0.95 = 336 watts. FTP = 336 watts
If you want to take this as the next step in your Power journey, after you’ve completed the ramp test on an ICG® indoor cycle bike, then you should aim to maintain around 105% of FTP for the time trial effort. You’ll likely flick between the yellow and red zones, but that’s okay – it just means you’re in the right place. Try using the lap button to record the TT effort as a lap, this will then give you the average output for that lap on the lap summary screen.
Finally, stay seated throughout the effort. We know you can push more power standing up, but it’s not a sustainable position for very long periods, so we need to know what you can do from the saddle. Also, there’s no hard and fast rule for preferred cadence. The slower you go, the more fatigue in your leg muscles will influence the result. The faster you go, the more stress there will be on your pedaling efficiency and cardiovascular system. We tend to advise most people to aim for between 85 and 95 RPM.
Good luck!