Whether you’re new to riding with power or highly versed in the ways of watts, FTP assessment is one of the most important—yet most poorly performed—aspect of power-based training.
Overview
You can see how under-utilized assessment is in the world of cycling by quickly skimming the backlog of 20-minute & 8-minute tests in TrainerRoad, where you’ll see workout after workout missing the steady-state objective by blowing up early, finishing too strongly, continuous upward-ramping effort, or riding so steadily that it’s clear it wasn’t a maximal effort. The goal of an FTP assessment is to serve as a useful & accurate estimate of Functional Threshold Power; however, these errors illustrate that athletes are missing the goal of assessment.
The point of this article is not to be critical or blame one aspect or another; rather, we’re interested in helping riders of all experience levels make the most of their test workouts to get the most value from all workouts following their test. Keep in mind that all of your TrainerRoad workouts will be based off your FTP test, thus emphasizing the importance of proper assessment.
What is FTP?
I’d venture to say that most riders understand that FTP assessment is about deriving their FTP. But what does FTP really measure?
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. This doesn’t mean much unless we talk about FTP in relation to goal duration which, in this case, is upwards of 20 minutes.
And while FTP goes by many names, it’s basically a measure of your ability to maintain a high—but manageable—workload for a somewhat lengthy duration, one where your lactate production has risen, leveled off, and then closely matches your lactate removal and just barely keeps that flooding at bay.
Trying to sustain 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.
This is a very trainable physiological response and a useful measure of fitness, one in which a structured, progressive training plan tempered with adequate recovery can bring consistent and lasting increases.
Why Assess Your FTP?
Let’s move on to the ‘why’ of assessing FTP. Then, we’ll discuss the ‘how’.
When creating workouts, we have to anchor our power zones onto something, so we your measure of FTP. Here’s why: a lot of fitness scientists and researchers who are smarter than us have done the legwork and applied it to generations of endurance athletes, providing us all with the benefit of their findings without retracing their steps.
So because we use this measure of fitness as your anchor and the basis for all of your training, it’s important that this number estimates your actual sustainable-power threshold as closely as possible.
By riding as hard as you can, relative to the 8- or 20-minute durations, we 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.
This is what we’re trying to find (regardless of your selected testing format) and it’s what we use over time in order to track changes in your fitness.
How to Assess Your FTP
When it comes to testing your FTP it’s important to keep your focus in order to overcome a few challenges athletes commonly face along the way.
Challenge 1: Don’t Go Out Too Hard
This is the heart of the ‘how’ of FTP assessment. It really boils down to what I just mentioned above: walking the tightrope between hard work and too-hard work.
The biggest challenge you’ll face is finding your balance early enough in the assessment so that you don’t waste the early minutes with effort that’s too low, nor sabotage the final minutes with early effort that’s too high.
After all, the goal 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.
Challenge 2: Pace Yourself
The next biggest challenge is pacing yourself throughout the test. This is best accomplished with subtle increases and decreases in effort every couple of minutes during intervals. In the case of the 20-minute test, we prompt you to evaluate your effort every five minutes. In the 8-minute test, these reminders happen every two minutes; however, you can do them at any interval that suits your level of concentration, focus and motivation.
As you evaluate yourself, keep your subsequent changes small. Something along the lines of a 2-3% change is all it should take to either clear muscles that are starting to load up or push a little harder without loading them up.
For example, a rider powering along at 220 watts might ease off or pick things up by 4-6 watts — not much at all.
Challenge 3: Don’t Save It For The End
The final challenge is avoiding the temptation to surge to the line and skew your FTP-estimate with a big dose of anaerobically-driven power at the end. This is a tactic you can use anywhere else but not during an FTP assessment. Use it at the end of an interval, at the end of a race, at the end of a group ride — but not at the end of an assessment.
Surging to the line not only inaccurately inflates your average power, but it also suggests that you held back too much during the bulk of your assessment.
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Here’s to hoping this advice proves useful and saves you the misery or repeating your assessment workout or mistrusting the results of one you might be questioning. Good luck!
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Could you characterize the effort required once more? If I’m able to hold a certain output for the duration, what kind of condition should I be in at the end of it? Should I be a puddle, gasping for air, or just breathing strongly after powering through to the end?
I guess what I’m asking for is to explain what to leave in the tank as it’s hard to discern what is anaerobic capacity and what is unused aerobic capacity in the tank at the end.
Ki Karl,
Apologies for the delayed response, I’ve been out of the office for a few days.
It’s a maximal effort, but it’s one that’s drawn out over 8-20 minutes, so it’s largely aerobic (minimal muscle burn) with a bit more anaerobic contribution for the 8-minute repeats (only slightly more muscle burn) and it’s safe to say you can only go so hard even if you simply want to sustain your power.
Then it’s really a matter of how much you can hurt, a.k.a. pain management.
Sounds rather dramatic & extreme but maximal efforts by their nature are uncomfortable affairs and assessments of any duration become more about pain management than aerobic/anaerobic contribution.
Starting hard-ish and simply sustaining pace will see to it that things seem harder requiring your focus to grow as the workload/watts increase by small increments until they probably level out leaving you to struggle (without form intact though!) to maintain until the end.
Paced well, you’ll be in a tough spot during the opening minutes, a tougher spot during the second quarter, tougher still during the third, then the closing minutes will marginally grow your discomfort as the seconds pass like days, all the while your watts move very little.
Think of it more in terms of “pain escalation” than “power elevation”.
By finishing feeling like you couldn’t have driven the power higher without fading, which in my experience has my breathing topped out but never gasping, is the goal but it means committing to a slightly worrisome pace early on because the real issue, again, is starting at a high level of discomfort and accepting that you have to stay there for a while – pain management.
I hope this helps, Karl!
Thanks Chad! I pulled off a decent effort that followed your recommended progression of discomfort. I have some additional room to increase the pain, but generally I feel as though my result was within 10–15 W of where I should be.
Now just to deal with it being lower than I want…
Thanks again!
I just did the 8 minute test yesterday. My question is how to do it properly using the Wahoo Kickr? To keep a consistent effort should I be changing gears or level?
Thanks
JD
Hi JD,
If you do the workout in Erg mode, the software will automatically switch to you to slope mode (level 3) for the assessment efforts. Then, it’s a matter of finding your gearing/cadence which could well involve a bit of shifting.
Often enough, once you’ve leveled out into your highest pace, you probably won’t shift much from there on, maybe not at all.
Here’s some more information, JD: http://support.trainerroad.com/hc/en-us/articles/201869584-Testing-on-an-ERG-Trainer
Hi Chad
I’m using Trainerroad since December last year. After more than 6 months and a several FTP assessments I have improved from 180 to 255 (at 67kg) and got a little bit of experience in the FTP testing (pacing is ok). So far I did always the 8min FTP – it worked fine for all the Sweet Spot training plans. I wanted to continue with the Build Phase, but I could NOT finish several of those workouts, e.g. Ritter/BrokenFinger/Darwin…
I have the impression that the level of those workouts is much harder compared to the Sweet Spot training plan. Moreover I believe that the FTP value is probably far away from the Watts I could REALLY sustain for a full hour!
So I’ve tried the 20min FTP and it ended up on 240 Watts. And even that one is certainly not something I can sustain for 60 Minutes, even with very fresh legs. And btw I’m using Quarq/PM + Kickr (rentensioned to show same wattage).
What would you recommend in my situation? Keep on using 8min FTP but find some workouts to improve sustainable power?
In other words: The intensitiy factor of a workout doesn’t really tell me how hard it will be. For example I can finish a 60min workout with IF 0.9 that has a lot of short (but high) intervals. On the other hand, I can’t finish a 60min workout with IF 0.9 that has fewer but longer intervals (sustainable power). So even if my FTP assessment was properly done, I still face the problem that not all kind of workouts really fit my level.
How to deal with this issue?
Hi Tom,
This is a common issues that demonstrates how different types of workouts make good use of your estimated FTP while others don’t quite jibe with your TRULY sustainable, hour-power.
My recommendation is seldom, if ever, to reduce your FTP but instead to determine which workouts need slight modifications in Workout Intensity.
Every plan I’ve developed is an idealized version of what an athlete can handle, but I doubt there’s a single “ideal” athlete out there meaning you’ll always need at least SOME modification here & there if you truly want to personalize your training and make it the best plan for YOU.
This modification is usually subtle, e.g. 2-3% reductions, and often enough only affects the early intervals since many times the real necessity is a more rigorous warmup.
In any case, try reducing the intensity a little bit early in the intervals session and then raising it back up over the course of the workout, or just leave it there and COMPLETE each interval (with a mild reduction) which is the ultimate goal of every workout.
Let me know how things go after a handful of workouts and we can revisit this issue if you’re still having trouble, Tom.
I wonder how many of those surges at the end are actually in response to the instructions that Trainerroad gives during the sessions? Certainly in the 8 minute test, there are prominent instructions to give “everything you’ve got left!” and to “bury yourself!” during the last 30 seconds of each effort.
If people are following the instructions as they appear, it seems reasonable that at least some people – especially those who are unfamiliar with the methods except outside of what they’re reading right there in front of them – are going to interpret that instruction as “increase your effort with a huge spike”.
Perhaps the powers-that-be at Trainerroad should update the instructions to remove any ambiguities 🙂
Agreed, Harry. I’ll take a look at that ASAP. Thanks for reminding me!
Good point! I think I did that before (big kick at the end). On my most recent test I kept my head down and my output steady.
Hello Chad, I’ve taken some FTP tests in the last two years and got accustomed to the sensations of the 20 min: I think that the best indicator of a well performed test is the 30 seconds stomach crunch that follows the all out. Seriously.
During the last couple of times, however, I happened to stand and push on the pedals a few times when intensity was slowing down my legs. It took to higher numbers, but it was difficult to me to close the build plan workouts coming afterwords.
I think the ftp was overestimate during those tests (I use a Powertap so power consistency should not be an issue here) and have the sensation that standing, as we do climbing, is sorta like cheating.
Does the test protocol require it to be performed seated in a steady position, or is it not prescriptive?
Hi Andre,
I don’t find anything wrong with standing from time to time in order to get yourself back on track, especially if you’re just raising your power back to your intended output rather than sprinting and possibly artificially inflating your average power – so no worries there.
I think what’s going on here is you’ve stumbled onto some of the subjectivity of training. Some riders excel at the longer, Threshold intervals but suffer dearly during, say, VO2max intervals; other riders it’s vice versa. This is most likely just a matter of personal aptitudes, perhaps a matter of recovery, maybe even a matter of the temperature in your training room or something as ever-shifting as motivation.
Whatever the cause, these are the workouts/intervals where small modifications can go a long way toward producing better performance results.
In the case of more sustained, Threshold efforts in that 95-105% FTP realm, I usually try a small reduction of maybe 2-3% and find that this subtle decrease is just enough to keep me hanging on, completing the intervals, and deriving almost identically the same training effect at which the workout is aimed.
Overestimating FTP is a pretty rare occurrence and more often a matter of having a great day on assessment day and then almost being punished for it during subsequent workouts. So try a slight reduction when you’re not quite meeting your power Targets and see if it better keeps you on track and successfully completing most (if not all) of your intervals, Andre.
[…] however you decide to assess your FTP now, here is a post about useful tips to remember when doing FTP […]
Hi There,
I did my FTP 20min test while sitting in the saddle and started with a program. But now I would like to train more specifically for a heavy climb of 50-55min which I did a lot of times in the past and I would like to fasten my best time. I don’t have hills here outside, but I climb standing, and noticed that power outputs of 300W (FTP is 225) are much easier to sustain standing. So I figured I want to improve that time I can sustain that power. Is there a program or specific thing I can do or are there specific trainings I can do to improve that (standing climbs)? Suggested: standing climb FTP test for 20min and then train standing or?
I started the program sustained power build high volumen. And have my goal in 5 weeks. So I use trainerroad because I don’t have climbs here, and matter of fact, I like it alot!
Marlies,
Sustained power build makes good sense because of the emphasis placed on strength-endurance work, lactate tolerance workouts and the proper amount of intervals testing your aerobic capabilities. All this makes for more of a steady-state adaptation which can contribute to greater sustained climbing for road racers. If you plan on continuing to work on your climbing abilities after your goal, you’ll want to choose the Climbing Road Race Specialty plan. Regardless of whether you’ll be climbing in or out of the saddle, you need to execute against a specialty plan that places a heavier emphasis on sustained power rather than short, explosive power. Development in that area coupled with maintaining your aerobic endurance will serve to allow sustained percentages of FTP on the climbs you may face.
Hope this helps!
Is this right?
I started the Sweet Spot Base Low Vol I with a FTP of 188 after some adjusting. Now I am starting Vol II which starts with a FTP test. I’ve been riding with a very tough group, and listened to every podcast from the beginning. I went hard on this test and now it says my FTP is 262! I really dug in on this test, but is this real? I’d hate to think I’ve been dogging it for 6 weeks. I guess the pain will come. I’m 53, 5’9 206 lbs.
Hi – if I hit the blue ‘target’ line perfectly on a FTP test would my FTP come out at my current FTP or is some improvement built in? Just wondering how hard to go (I know, go as hard as you can!)
Hi Chad, got linked to this from support after asking questions there initially.
My question relates to cadence vs power in tests. I’ve done a couple of 8 min and one 20 minute tests, using an Erg trainer (slope mode assessment phases) and think I’ve got the pacing right each time. Certainly subsequent plan sessions have inflicted just the ‘right’ amount of pain.
My issue is that I have a wide range cassette 11-32 and in the last test found I could sustain a cadence of 103-105 in ‘4th from the top’, but in ‘5th from the top’ my legs would light up too much, so the way to increase power output was to increase cadence. I could push a little harder, but not as hard as the next gear required. I usually spin at 90-95 on the road, 85 ish on climbs unless hitting 15%+ out of the saddle sections, and worry that testing with an ‘unrealistic’ cadence may skew subsequent training. Does it matter ‘how’ the power is delivered, as long as it’s a steady state effort ?
Presumably the issue is my cardioresp system is stronger than my legs. The TR plans have definitely improved my performance, and ability to tolerate a fast spin for a long time, but perhaps not helped strength so much ?
Anyway, seeking some advice re the effects of cadence on test usefulness.
[…] websites I used as resource to figure out all of this stuff 🙂 And like any test, we always should prepare for it. How to prepare for an FTP test FTP testing explained on Trainer Road Guide to figuring out your power zones based on your FTP and […]