A Functional Threshold Power (FTP) cycling test is a straightforward, non-invasive method of assessing your cycling performance level. And is often used to establish specific cycling training zones.
In this article, we’re going to look at
- What is an FTP test
- How to perform an FTP Test
- Look at ways to increase your cycling FTP
What is an FTP cycling test?
Simply put, FTP represents the highest average power (measured in watts) you can sustain for one hour of continuous cycling. An FTP cycling test is used to measure or estimate your FTP.
Is the FTP the same as the lactate threshold?
Often, the term FTP is used interchangeably with the lactate threshold. However, whilst both FTP and lactate threshold occur at similar intensities, they are not the same.
The lactate threshold represents a physiological phenomenon (a specific rise in blood lactate), whereas FTP is best described as a performance measure — the amount of power sustainable for 1 hour.
The confusion occurs because on average the lactate threshold (LT) occurs at an intensity we can sustain for around one hour. However, there can be wide individual variation: for one athlete LT might correspond with an intensity sustainable for 50minutes, for another, it might be 70minute intensity.
So, while FTP and LT can occur at similar intensities, they don’t always correlate. In some cases the FTP might be higher than the lactate threshold, in others it might be lower.
Why use a cycling FTP test?
First, FTP is one of the most accessible and effective performance tests for endurance cyclists. It’s also relatively straightforward to test — all you need is a bike, a way to measure power (power meter, turbo trainer, training software, Smart bike etc) and the willingness to push yourself to your limit.
They can also be used to prescribe training intensities. And, once you know your FTP, you can then repeat the test to assess the effectiveness of your current cycling training program and track your progression.
Once you know your FTP, you can compare this in two ways:
- Absolute value — for example, an FTP of 380w
- Relative value — in relation to your bodyweight (for example, 380w/67kg = 5.67w/kg).
In this way, we can assess improvements/changes in absolute power, and how changes in bodyweight affect it.
How to measure your cycling FTP?
What equipment’s required? Either a bike fitted with a cycling power meter, a turbo trainer capable of measuring power, software (like trainerRoad) capable of estimating power, or a Smart bike, and a heart rate monitor to record heart rate during the test.
Considerations and precautions before testing: The test itself is a prolonged high-intensity cycling test, completed at an intensity just below VO2max. Therefore, it’s important to have a good basic fitness level and training experience before putting yourself through the test. You should be injury free and not have any serious underlying health conditions.
FTP cycling pre-test procedure:
Prior to testing, ensure that your power meter, or turbo trainer, is calibrated (if required).
Include a good warm up: Ideally for around 15 minutes — this should include some short accelerations that go above expected FTP power.
Different FTP cycling tests:
To assess/estimate FTP itself, we have a few options:
#1 60-minute FTP test
The 60-minute cycling test involves riding as hard as possible for 60minutes, whilst recording power and heart rate.
We use the average power sustained across the 60minutes as the measure of your FTP.
Whilst we consider this the most accurate; it’s extremely difficult to maintain your highest power for 60minutes, especially in a non-competitive situation — for most athletes, this just isn’t realistic.
Even if you’re highly motivated, it will be extremely difficult to maintain your highest power for 60minutes. And you’ll likely record a lower average power than you could sustain during a competitive situation.
A more practical option, is the 20-minute, or 8-minute test.
#2 20-minute FTP test
As with the 60minute test, this is all about average power — cycle as hard as you can for 20minutes, whilst recording your power and heart rate.
The average power from the 20-minute test can then be used to estimate your FTP. Here, we simply multiply the average power for the 20minutes by 0.95.
Whilst this test sounds straightforward, it’s mentally challenging — especially when you’re counting down the minutes! So, there’s no point attempting this test if you’re not sufficiently rested, and well-motivated.
Another option is an 8minute test.
#3 2 x 8minute combined VO2max and FTP cycling test
The 2 x 8-minute test is another straightforward option for estimating FTP.
An advantage with this test is that we can also estimate the power at VO2max.
It’s important to remember that this is just an estimation of your power at VO2max. Since we’re not testing VO2max itself, we can’t be certain that this power correlates with your VO2max. That said, it will be pretty close.
Because the intensity of this test is higher — the first 8minute interval is at around VO2max intensity — we need to ensure that we include a thorough warm up.
So, how does this test differ from the 20-minute FTP tests?… There’s, two key differences:
- First, the intensity is greater.
- Second, the test involves completing two intervals rather than just one — 2x ‘maximal’ 8-minute tests, separated by 10 minutes of easy cycling.
The results from this test provide an estimate FTP and VO2max power.
How to complete the 2 x 8minute test:
- Following a good warm-up, complete the first 8-minute interval at the highest power/effort level that you can sustain. Try not to think about the second interval, just focus on maintaining the highest sustainable power for the first 8 minutes.
- Once completed, cycle at an easy intensity for 10minutes.
- Then, complete a second 8-minute interval, again at the highest power you can sustain. Expect your average power to be lower during the second 8-minute test. As an example in my recent test my power was 3.5% lower for the 2nd 8-minute interval.
How to interpret the 8minute test data
The average power from the first 8-minute interval gives us a measure of the power at VO2max. We can then use this for setting power targets for VO2max cycling intervals.
To estimate FTP from this test, we average the power from the first and the second 8-minute intervals and then multiply this by 0.9.
So, how does this compare with the 20minute test? My experience (and many others) shows this to be highly comparable to predicted FTP from the 20-minute test.
When I recently completed the 2 x 8min test, my predicted FTP was within 0.5w of the estimate from the 20min test. So, for me the 2 x 8minute test is a great alternative.
One further option is a ramp test, or maximal aerobic power (MAP) test.
#4 Ramp/Maximal Aerobic Power Test (MAP)
The ramp test can be a useful option. And it’s slightly less stressful and easier to complete for most cyclists. It differs from the earlier tests in that this follows an incremental protocol — the work rate increases in increments throughout the test until you can no longer complete a work stage.
How to complete a RAMP test
- First, they build RAMP tests into many online programs like TrainerRoad, Zwift and the WattbikeHub; making testing straightforward if you have access to these.
- During the test, work rate will increase in 1minute increments — normally starting at a fairly low/easy intensity.
- Workrate is normally increased in 15-25w increments (depending on fitness/conditioning and gender)
- Continue until you can no longer maintain the target power.
- Average power over the last minute is used to calculate VO2max and FTP
Interpreting the RAMP test:
If you’re using a training program, then this will automatically calculate FTP and VO2max.
FTP is normally calculated as being 75% of maximal aerobic power (MAP); with MAP being the average power over the last minute of the test.
There’s one downside to using a RAMP test for FTP estimation: FTP doesn’t fall at the same percentage of MAP for every cyclist. For some it might be 72-75%, for others it’s nearer to 80%, and for some it’s above 80%.
It largely depends on whether your strengths fall more on the endurance, or sprint end of the spectrum. Typically, if you have a very high level of aerobic endurance, then your FTP will occur at a higher percentage of MAP. So, this test can be less accurate if you don’t know what percentage of MAP equates with your FTP.
How to use your FTP cycling test results to set training zones:
Once you have your FTP test data, you can then use this to establish your training zones; based around percentages of FTP power and heart rate.
If you’re using training analysis software like TrainingPeaks, FinalSurge, Strava, or training programs, like Zwift, TrainerRoad, and Sufferfest; then these can automatically calculate training zones based on your test result.
These zones can then set power targets for your training rides, intervals, and recovery rides.
Below are the most commonly used training zones, originally proposed by Allen Hunter and Andy Coggan in their book Training and Racing with a Power Meter.
|Zone||Purpose||%FTP||% FTP HR||RPE||Effort sustainable for*|
*Approximate values, which are highly individual.
These give a good basic framework. One downside here is the wide power range for each zone. Another factor is heart rates don’t always match with corresponding power zones.
Fine tune your training zones for more effective training
If you have a coach, then they will most likely look to narrow the range of these zones; making these more specific to you, and your own training/racing targets.
Except for the endurance and recovery zone, I prefer to narrow these zones down to a 5-8% range.
Here, the 2 x 8minute test can be useful as it allows you to be more specific with your VO2max power zone. From the 2 x 8minute test the average for my first 8minutes, was ~113% of FTP, allowing me to refine the VO2max power zone from 106-120% of FTP, to a 5% range of ~113-118%FTP.
That said, it’s important to remember that just like FTP testing, this provides an estimate, and it’s not actually measuring VO2max.
How to improve your cycling FTP
As the saying goes “If you can measure it, you can improve it” – and your FTP is no different!
Simply put, specific targeted training will improve your FTP. Here, there are several different approaches that will all help to raise your FTP.
The traditional approach is to focus on endurance miles, combined with specific intervals completed at close to FTP. Normally, this involves longer intervals, such as the classic 2 x 20’ completed at close to FTP.
However, the best long-term approach is to use a range of training intensities — some above, some below, and some close to FTP intensity — or lactate threshold (if you’re using a lab based test).
Ideally, you’ll want to include:
- A substantial amount of low intensity endurance training to build your aerobic base
- Tempo, lactate threshold or supra-threshold intervals, to improve your ability to sustain a higher percentage of VO2max
- VO2max intervals to develop top end aerobic fitness and efficiency
- Supramaximal intervals to enhance neuromuscular co-ordination and peak power
- Strength training to improve strength, power and efficiency
Training specificity is important
In terms of specificity, training slightly above your FTP intensity is actually more specific for improving your FTP score than training at your FTP!
If that sounds counterintuitive, think about how most cyclists assess their FTP… through a 20minute maximal test. And not through a cycling test at FTP intensity.
In this way, training at FTP will help to improve your FTP, but it’s actually less specific for improving 20-minute power – which is what your testing during a 20minute test.
So, if you’re using the 20minute test to assess FTP, and you really want to improve your FTP score; the best approach is to be specific, and train at close to your maximum 20-minute power.
Not only will training at that intensity better prepare you physically, but you will be mentally more prepared. Specifically, you’ll be more accustomed and more comfortable at that intensity.
Whilst I’m not advocating training just to improve a test score; I’ve seen real benefits from training just above the intensity of FTP (specifically supra-threshold intensity). This can really benefit endurance cycling across a range of events. And it’s especially useful for events lasting from ~15-60minutes.
How often should you test your FTP?
If your highly competitive (either with yourself, or against others), then it can be tempting to overuse FTP tests. However, that will not make you a faster cyclist — well, not in the long run — we need to use these tests sparingly and appropriately.
So, what’s a good frequency for FTP testing? First, they’re challenging tests — both physically and mentally. To get the most from these we don’t want to overuse them.
Second, if we think purely in terms of training adaptation; any change to training (especially if you’re well trained), typically takes a minimum of 4-6 weeks to have a noticeable effect. In view of this, there’s really no need to include FTP tests any more frequently than every 4-6 weeks.
My preference is to use these less frequently — ideally with around a 6-8-week gap between tests. So, unless you’re relatively new to training, or there’s been an obvious jump in fitness, 6-8 weeks is a good frequency for most cyclists.