An FTP test is a way to determine your current performance level on the bike. There are different methods to test your FTP (Functional Threshold Power), and some are better than others in terms of providing actionable data to help you improve.
In this article, I’ll talk about what an FTP test is and is not, and show you how to properly test your FTP and use it to improve your cycling performance.
Beginners and advanced athletes alike will benefit from better understanding and applying this knowledge about FTP.
Knowing your FTP and how to properly use it will enable you to:
set better goals,
accurately plan your training,
check your progress, and
adjust your training and racing strategies to meet your goals.
This applies to ANY cycling event, from sprint triathlons, Ironman races, your local crit race, to top world tour cycling stage races.
What is FTP?
FTP stands for Functional Threshold Power and is a standard used by many cyclists to measure and track their performance. It is generally considered to be the average power a cyclist can sustain during a one-hour steady state best effort (as hard as possible) time trial.
More scientifically, this hour duration effort is regarded as a good physiological marker for an athlete’s maximal lactate steady state (MLSS), or where the rate of lactate production in the blood is equal to the rate of lactate clearance.
The MLSS is important to know. Lactate is produced by the anaerobic system and used as a fuel source by the aerobic system. However, when an athlete performs at an effort level that is above the MLSS, the athlete will accumulate lactate in the body, and this accumulation of lactate is what rapidly causes the athlete to slow down.
An athlete can perform for long periods of time (hours) at just below the MLSS, but only for short periods of time (minutes) above the MLSS. If you know at what power your MLSS occurs, you can determine the maximum average power output you might be able to cycle for a given duration, such as during a race.
You should also know your current FTP to help determine how effectively you are training. Performing periodic FTP tests on the bike will tell you whether your recent training has been successful.
If you perform the right test, you can also determine how your FTP is “composed,” which will give additional insights on HOW TO train for your goals. I give more information on this in the section below on the lab and INSCYD tests.
What Gear Do I Need to Test My FTP?
Besides a bicycle, a cycling power meter is the most crucial piece of gear you will need to perform an FTP test and train using power. A power meter measures how fast and hard you pedal, and reports the value in watts.
There are many different power meter options that work well. Consider how you will use power in your training and racing, and this will help you determine which type of power meter to get. Here are some considerations that assume you want to use power on most or all of your riding, including racing:
Indoor + outdoor training - if you often train on an indoor cycling trainer, then it will be good to have a power meter that works with your indoor trainer. This power meter can be on your bike if it is compatible with your trainer, or it can be on the trainer itself, in the case of a smart trainer.
Multiple bikes - if you have multiple bikes and want to use power on all of them, then your best option will be to get power meter pedals that you can easily switch between bikes, or purchase a power meter for each bike. If you choose the second option, then you should also be sure the multiple power readings are reproducible. That is, be sure the power meters are accurate enough to give similar power numbers.
On-bike power + indoor trainer power - if you have a power meter on your bike and a power meter on your indoor trainer, make sure that they provide reproducible power numbers so you can be confident that your power readings are similar between the two, indoors and outdoors.
Another piece of gear that is useful is a chest heart rate monitor. If used correctly, heart rate in conjunction with power can guide your training better than just power.
Which FTP Test is Best?
There are several different FTP tests, and each one has its benefits and drawbacks. The best test for you depends on how you will use the results.
1. 5 Minute Plus 20-Minute “Standard” FTP Test
Perform two intervals all-out: one interval for 5 minutes, and one interval for 20 minutes. The five-minute interval should be done hard. Don’t slack. Estimate your FTP by taking 95% of the average power for the 20-minute interval.
Benefits: Relatively straightforward test (but not easy!) that you can repeat as training progresses.
Drawbacks: Can be hard to correctly pace the intervals. You need to start hard and stay hard without dropping power too much at any point, or the FTP estimate will not be accurate.
2. FTP Ramp Test
Start at an easy level, and in increments (usually 1-3 minutes), increase power output by a little bit until you can’t increase anymore. Estimate your FTP by taking a percentage (usually 75%) of the average power of the last minute of the ramp.
Benefits: Simple to pace and perform (but still a hard effort!) and often gives more accurate results than the 20-minute test.
Drawbacks: The ramp intervals need to be well-designed for your particular cycling style and physiology, or the results will not be relevant. The results also need to be analyzed by a person who can accurately identify the threshold.
3. The One Hour FTP Test
Another simple but not easy one. Ride as hard as you can for 1 hour. Estimate your FTP by taking the average power for the entire hour.
Benefits: If you like pain, then this test is for you. If you’re sufficiently motivated and you are able to give a hard-paced effort, such as during a 1-hour time trial race, then this test is very accurate because it is the definition of FTP.
Drawbacks: The one-hour FTP test can be very difficult to correctly perform. That’s because it is an entire hour of riding absolutely as hard as you can. Think vomit-inducing levels of pain. The pacing is also hard to get right. You have to start hard and keep it up the entire time without dropping power.
This test is also more difficult to periodically repeat than other tests when you want to check your training progress. It is a very hard workout and so will require some extended recovery.
4. Lab Tests - VO2max and Lactate
This test requires laboratory equipment and other people present who know how to use the equipment and perform the test. Equipment may include a gas exchange analyzer and a blood lactate analyzer, which can provide very accurate results. You perform a test (often a ramp test) while wearing a mask that measures your respiration rate and analyzes the air you inhale and exhale before and during the test.
Another person in the room will also take blood samples at defined intervals and place them in a lactate analyzer device to determine the amount of lactate that is accumulating in your blood. Your VO2max and lactate values will be used together to accurately determine your current FTP.
Benefits: Very accurate if done right. The biggest benefit here is that this test breaks down how your different metabolic systems are contributing to (or hindering!) your FTP. It also helps inform you HOW TO train, not just how you have been training.
Drawbacks: Can be expensive, you have to go to a test facility and so it’s harder to periodically repeat throughout the season and requires other people to help administer the test.
Also, although the test can be very accurate and extremely useful, cyclists need to know how to use the results to properly analyze and adjust their cycling training.
5. INSCYD Test
This is a relative newcomer test, and a very exciting one indeed! It provides the convenience of the at-home FTP field tests with the insights of the laboratory tests. It is essentially a virtual lab test.
The scientists and coaches at INSCYD have extensive research data that they used to create a software program that accurately correlates different VO2max and lactate values to power values.
The test protocol is flexible, but usually, you perform four efforts on the bike: 12 seconds, 3 minutes, 6 minutes, and then 12 minutes all as hard as possible. The average power from each of these efforts is put into the software, and the program gives your unique cycling physiology, including the relative strengths of your aerobic and anaerobic systems.
From this information, you can accurately determine not only how you have been training, but also how you should train in the future. None of the other field tests can provide this information, only the laboratory test.
Benefits: Easy to perform at home or in the field, as accurate as lab tests, and gives the most actionable data of any test. This combination makes it probably the best suited FTP test for athletes who want to maximize the effectiveness of their available training time.
Drawbacks: Costs some money and requires a knowledgeable individual to analyze the data in order to prescribe the right course of action for optimal cycling improvement.
Full disclosure: We offer INSCYD tests at Paragon Training as an option for our athletes to better understand their physiology and create effective training plans.
The bottom line recommendation is to choose a test that works for you and stick with it for your entire season. This will remove the potential variability of different types of tests so you can more accurately track your progress throughout a season.
How Often Should I Test My FTP?
You should test your FTP at a minimum before starting a new training season. This will help you determine your initial training zones so you can perform at the right intensities for your workout and training plan goals.
However, as you train, your FTP will change (hopefully go up!). You will want to monitor your progress as the season goes along. Therefore, it is ideal to re-test your FTP after performing a substantial block of training, such as an 8-week base aerobic block or a 6-week hard build block.
Frequent re-testing (every 6-8 weeks) will help you determine if you are improving, and it might help you determine how you need to change your plan to keep improving.
Here is the basic training paradigm for using FTP tests to achieve athletic success:
Test - Accurately perform the test
Analyze - Interpret your test data
Plan - Prescribe training according to the test data
Execute - Do the training as prescribed
Re-Test - Retest your progress
Re-Analyze - Analyze your progress
Modify - Change your training according to the new data
Repeat!
How Do I Set My Training Zones Using My FTP?
After you perform an FTP test, you will want to use the results to train. To do this, you will first set your training zones using the results of the FTP test. There are several ways of going about this. The simplest and most common (but not always best) way is to assign a range of percentages of your FTP to correspond to different desired physiological adaptations. Here is an example of a typical set of FTP-based training zones and their target physiological adaptations:
Zone 1 - 45-60% of FTP - Recover from harder training
Zone 2 - 60-75% of FTP - Improve basic aerobic system
Zone 3 - 75-85% of FTP - Improve both aerobic system and ability to hold power near FTP for a sustained duration
Zone 4 - 85-95% of FTP - Increase duration of power just below or right at FTP
Zone 5 - 95-105% of FTP - Boost VO2max, which will boost FTP
Zone 6 - 105-120+% of FTP - Increase anaerobic system, which enables the ability to execute short-duration intense efforts
When you accurately know these zones, then you can train more accurately to improve specific metabolic systems, which will, in turn, lead to better performance in your goal events.
However, this approach is generic, and may not be appropriate for your unique physiology. For instance, your Zone 2 may not be in the generic Zone 2 range of 60-75% of FTP.
How Does My FTP Compare to Others?
If you’re the competitive sort, then you’ll want to know how your FTP compares to others. This can be useful to see how you might perform in events compared to others, but there are other factors to take into account.
How fast you actually go in a cycling event is based on many variables. The biggest factors are your aerodynamics and weight. You want to be generally more aerodynamic and lighter. But you have to balance that with comfort and the ability to sustain a given power output.
If you’re too hunched over in an attempt to improve your aerodynamics, you might not be able to utilize your muscles as efficiently to produce power. Also, if you’re too light, it might mean that you don’t have enough muscle mass to produce optimal power.
The metric that most cyclists use to compare their FTP to each other is their power to weight ratio, usually expressed in units of Watts of power output on the bike per kilogram of body weight, or W/kg at FTP.
You can improve your W/kg at FTP by either increasing your FTP or decreasing your body weight, or both. Knowing your FTP and body composition, and how they relate to other cyclists, can help you determine how you might benefit from altering your body composition.
You might find that your W/kg would most benefit from losing weight through body fat. Conversely, you might find you would most benefit from increasing muscle mass, which could increase your body weight but would overall increase your W/kg. The increased muscle mass could significantly increase your ability to produce power.
How Do I Best Increase my FTP?
The best way to increase your FTP is to determine how your two main metabolic systems (aerobic and anaerobic) contribute to your FTP, and then train those metabolic systems appropriately based on your goals.
The strength of your aerobic and anaerobic systems and their relative contributions to your FTP can be determined with a lab test or the INSCYD virtual lab test.
For example, let’s say you want to train for an Ironman triathlon. After performing an INSCYD test, you discover that your anaerobic system is contributing a disproportionately large percentage to your FTP (this is surprisingly more common than you might think). Since you’re training for a 4-7+ hour cycling event, it is less desirable to have a strong anaerobic contribution to your FTP.
You can only utilize your anaerobic system for relatively short durations—not for many hours—so you want to increase your aerobic system’s contribution to your FTP and decrease the anaerobic contribution. This will enable you to cycle for a much longer duration at a power output near your FTP.
Additionally, you’ll want to train to increase your aerobic system’s ability to produce power and thus increase your overall FTP. This can be accomplished with different types of training.
An example of this type of training would be to perform weekly repeated intervals at low cadence 50-60 rpm (pedal revolutions per minute) at a power output just below your FTP in a typical “Zone 3-4” power zone.
Having the physiological insights of an FTP test, or one of the more advanced lab FTP tests or an INSCYD test can be very powerful to help you as a cyclist to improve as much as possible with the time you have available.
Your task is only beginning after you perform the test. You then need to determine how to train in order to optimize your FTP for your particular goals and monitor and adjust your training to ensure you stay on track.