Whether you’re new to riding with power or highly versed in the ways of watts, FTP assessment is one of the most important aspects of power-based training.
For more training tips and information on the Ramp Test check out Ask a Cycling Coach Ep 249.
What is FTP?
Your Functional Threshold Power, or FTP, is the foundation upon which all of your power-based workouts are built. In essence, it’s the measure of your highest sustainable power for an extended duration. In theory, it’s supposed to represent the maximum power you can sustain for an hour, but in the real world most riders have trouble sustaining it for much longer than about 30 minutes.
Physiologically, FTP is analogous to Lactate Threshold– the point at which your lactate production has risen and leveled off, closely matching your lactate removal ability. Sustaining high effort for durations of this length pushes you into that grey area between power you can sustain all day and the fleeting power you can only tolerate for a couple of minutes.
What is an FTP Test?
An FTP test is a physical assessment, intended to evaluate your Functional Threshold Power (FTP). In an FTP test, you attempt to sustain the highest workload you can for a specific duration of time. An estimate of your FTP is calculated from your power output, and from this result your workouts are tailored to your personal fitness. For the most effective workouts, your FTP should be assessed every 4-6 weeks, so your training plan can keep pace with your current abilities.
Types of FTP Tests
Since FTP is supposed to represent the power you can sustain for an hour, the most obvious way to test FTP is to ride as hard as you can for 60 minutes and measure your average power output during that time. In practice this is extraordinarily difficult to pace correctly and incredibly fatiguing, so most testing protocols use approximations derived from shorter efforts.
TrainerRoad’s preferred FTP assessment is our Ramp Test. The Ramp Test begins with a 5-minute warmup, and then every minute thereafter it gets slightly harder until you cannot maintain target power any longer. 75% of the best one-minute power you achieve during the test is used as your FTP. Our data shows the Ramp Test results in the most accurate and useful FTP estimate for the majority of riders using TrainerRoad. Since it is quick (normally about 25 minutes including warmup and cooldown) and fairly easy, it can be taken frequently to track changes in your fitness.
Perhaps the best known FTP testing method is a 20-minute time trial. In this format, you ride as hard as you steadily can for 20 minutes; 95% of your average power during this interval is used as your FTP. Another common method is the 8-minute test, in which you ride 2 all-out 8-minute intervals with 10 minutes of rest in between. In this format, your FTP is derived as 90% of the overall average power of the 2 efforts. TrainerRoad offers both of these tests as options, but they are more subject to pacing, fatigue, and equipment challenges than the Ramp Test.
The FTP estimate you obtain from an FTP test is used to calibrate your training zones and set the intensity of your workouts. Without actually testing your Lactate Threshold and VO2max in a lab, your FTP is an approximation. But, the applicability and usefulness of this number has been proven by generations of coaches and endurance athletes.
Because we use this measure of fitness as the basis for all of your training, it’s important that this number estimates your actual sustainable-power threshold as closely as possible. This is why it is important to test your FTP and test it often. An effective test can extrapolate the point at which your muscles are successfully walking that lactic tightrope and maintaining the balance between hard work and too-hard work. Testing repeatedly over time tracks changes in your fitness, allowing your workouts to be calibrated to your current abilities.
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How To Pace an FTP Test
20 Minute Test
The goal of the 20 minute test is a steady-state effort—one that sees minimal fluctuations in power output and limits the unavoidable zigs & zags to a tight range close to that not-too-easy/not-too-hard power figure. This is best achieved with fresh legs and a fair amount of practice. Unfortunately, riders assessing for their first time don’t have the luxury of the latter.
So the advice is simple: don’t go out too hard. At the same time, you don’t want to go out too easy. But with no informed idea of either, you can only guess where to start things off. The best way to do this is by holding back a little bit at first. So, go hard but know that you’ve got a little room to grow. We recommend riders reassess their pace every 5 minutes during the test, and that any adjustments be just a few percent at a time. Many athletes ride these long efforts too conservatively and surge their power during the last 2 minutes, this skews the results and should be avoided. You should arrive at the last 5 minutes just able to hang on and maintain steady power.
8 Minute Test
The individual efforts of the 8 minute test should be harder than that of the 20 minute test, and should represent power at VO2max. However, like the 20 minute test these efforts should be as steady as possible. Power data for perfect execution of the 8 minute test will result in two efforts that look like subtle smiles, with a slightly higher output during the beginning and end of each interval and a steady effort during the middle. If you have a dramatic spike at the beginning or end, it’s an indication of bad pacing.
Reassess your effort every 2 minutes during the 8 minute test, but any pacing adjustments should be subtle. The 2 efforts should be as similar as possible, if your second interval is much weaker than the first it’s a clear sign you started too hard.
The beauty of the ramp test is that it requires no pacing strategy. Instead, the key is to absolutely empty the tank. Follow the intended target power as closely as possible for as long as you can. Even a few seconds more when you think you are done can yield meaningful data, so you should ride until you physically can’t maintain power any more. You should not make the conscious choice to stop- instead, your legs should override your brain.
You don’t need to do any openers prior to starting your Ramp Test. While doing some openers is a great way to psychologically prepare your system for hard efforts, we intentionally designed the Ramp Test to not require any additional form of preparation. You also don’t need to do an extra warm up before you start the Ramp Test; we’ve tested and found it did not alter the results in a meaningful way. The first 5 minutes are naturally very easy and will prepare you for the harder efforts to come.
FTP Testing Tips
- Aim for consistency. Your preparation for your test should be the same as for any other workout. Calibrate your power meter, maintain your usual cadence, and hydrate and fuel like you normally would. Use the same equipment and setup for each test so the only variable changing is your fitness.
- Accuracy is your goal. Getting an accurate FTP is more important than getting a new personal record. Although it would be difficult to do so anyway, “gaming” the test wouldn’t offer you any benefits, as the result would be inapplicable to training.
- Test frequently. Our training plans include Ramp Tests every 4-6 weeks, but whatever protocol you choose it’s good to test regularly to track changes in your fitness.
- Be rested and well-fed. Testing when exhausted or under-fueled will not reveal accurate results.
- Don’t forget about cooling. For indoor tests, a good fan is crucial. Place it at the base of your bike and aim it at your body, or put it front and center on its high setting. 75% of your energy goes into thermoregulation, and this is particularly important at high intensity.
- Retest when changing power sources. Moving from a smart trainer to an on-bike power meter, or from one power meter to another, can reveal different results. You might get lucky and find your devices match each other perfectly, but it’s always a good idea to find out.
- Don’t obsess over the results. Your FTP is not a measure of your self-worth. If your FTP goes down, don’t worry about it. Everyone has ups and downs and your training will adjust to match your ability.
Here’s hoping this advice proves useful. Good luck!
Note: This post has been updated to include information about the Ramp Test, which was introduced after its original publication. The update includes contributions from Meghan Kelley and Jonathan Lee.
For more cycling training knowledge, listen to Ask a Cycling Coach — the only podcast dedicated to making you a faster cyclist. New episodes are released weekly.
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