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FTP Calculations

FTP (Functional Threshold Power) is automatically calculated upon completion of any of our test workouts.


20-Minute Test
FTP

TrainerRoad calculates your FTP from the 20-Minute Test by multiplying your average power for the test interval by .95. In other words, your FTP is 5% less than your average power of the test interval.

 

8-Minute Test
FTP

TrainerRoad calculates your FTP from the 8-Minute Test by multiplying your average power of the two test intervals by .9. In other words, your FTP is 10% less than your average power of the two test intervals.

 
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Comments

  • Avatar
    Charlie Goh

    Hi Guys
    Just wondering why I don't see my LTHR on my home screen or on any of my tests. Thanks. - CGoh

  • Avatar
    Larry Sussman

    Hi Charlie,

    Thanks for the comment! We don't actually show LTHR values on your online Career or in your ride summaries. We mostly focus on power data and metrics, since our workouts are primarily power-based. However, you can view your LTHR value in the "Profile" tab of the app or website, along with your FTP, weight, and other information. :)

  • Avatar
    Sarah PDX

    I'm looking at my "Profile" tab on the website (https://www.trainerroad.com/profile/rider-information) and don't see LTHR anywhere. I see: Gender=female, Career&Workouts=private, Units=Standard, Enable VirtualPower=no, Weight=XXX, FTP=XXX, TimeZone=XXX, and that's it.

  • Avatar
    Ralph Abelardo

    It should be the profile tab on the trainerroad app not on the site.

  • Avatar
    Charlie Goh

    Got it - thanks for that

  • Avatar
    André Lemos

    the first time I did the 20 minute test, I didn't had HR data, but I am wondering if it's worth it calculating my LTHR on the trainerroad scope. Is it used anywhere, for anything? I naturally understand the need for power, but is LTHR used for anything?

  • Avatar
    Evan Cohen

    Hey André,

    TrainerRoad is all about power, and we don't want our users to focus too much on LTHR. Power data is consistent, and LTHR can fluctuate due to a number of things. If you want to learn more about the differences between training with LTHR and Power, check out this blog post! http://blog.trainerroad.com/training-with-power-vs-heart-rate-whats-better/

  • Avatar
    Johan Forsmark

    Andre Lemos... Yes LTHR can be used in your endurance rides.

    Question to the coaches: why do i need to subtract 8% from my LTHR test in trainerroad (i do Allen and Coggans 30min test, and push lap button after first ten minutes). These guys says that my LTHR is the average HR from the test i do. What is right LTHR?

  • Avatar
    Thomas Willan

    Hi,

    I have tested FTP a few times using TrainerRoad and Sufferfest Rubber Glove. As far as I'm aware, TR calculates FTP when this video is used by taking the average power for the 20 min interval and multiplying it by 0.95. Today, however, I bailed out after 15 mins (with an average up to that point of 302w) and I got an update message saying my suggested new FTP is 281. Please can you let me know how this has been calculated? Is it reliable? The OCD in me says I should re-do the test, but perhaps this FTP estimate is good enough? I would have struggled to hold that average for the final 5 mins (ie I did go out a bit too hard) but I could have held perhaps 285 for the remaining 5 mins...

    I was surprised to receive the message suggesting an updated FTP when I hadn't completed the test. Just keen to understand the basis of that calculation.

    Thanks very much!

  • Avatar
    Jeff Liang

    Hey Thomas,

    That's a great question!

    I took a look at your Sufferfest Rubber Glove workout and found some answers.

    Take a look at the last interval you did (VO2 Max 1). Your average power was 296 Watts (don't confuse this with target power). TrainerRoad took that power and multiplied it by 0.95. In this scenario, 296 * 0.95 = 281.2 - your new FTP. Whether or not this FTP value is reliable is dependent on your ability to consistently ride with an average power of 296. For example, if you struggled to hold that average, it would have lowered your FTP. The same idea applies vice versa.

    As far as calculations go, I'd say this value is reliable. Whether or not the value is an indication of your actual FTP is based on your own judgement. Of course, you could always manually change your FTP in your profile tab if you believe the number isn't representative of your actual FTP.

    I hope this provides some clarification to your answer! =)

  • Avatar
    Thomas Willan

    Thanks for that. I guess I was just surprised that it gave me an estimated FTP using the 0.95 X average forumula despite the fact I didn't complete the 20 minute test. I guess I'll have to re-test and hold out for the last 5 mins if I want to be really sure!

  • Avatar
    Nathaniel Khoe

    1st Time 20 Min FTP

    Completed my 1st time FTP. Is it possible to have an overly inflated first time 20 FTP if you accidently spike up the first few pedal strokes? Used the Wahoo Kickr. Took a few seconds to realize you had to adjust the shift once in the last stage of the 20 min FTP program thus the spiked power surge on the first few seconds. If that is so, how much does it affect it? In denial that my FTP is what it is. I know other cyclist that have lower/higher wattage than me but they are way stronger than me. Night and day different......thus my questioning of my data.

  • Avatar
    Andy Daniels

    i just done the black giant 30 on my wahoo kickr. when i done my 20 min test it gave me a score of 263, however today on the mentioned session it was far too easy. i had to be in the bottom ring on the block to get any kind of resistance and when i came out of an effort and the power level drops it was impossible to go that low around 105 without stopping peddling. I've manually put it up to 300 as i have a friend around that figure who is a similar ability. hope this works next time. he tends to keep half way down the block and that works well. hope this is the right thing to do.

  • Avatar
    Nathaniel Khoe

    I found out my problem. Didn't do the spin down calibration on the Wahoo KickR. I'm literally 60+ watts lower than my initial 20 min FTP. This feels more like it. I didn't think my power was at 267. Closer to 200ish.

  • Avatar
    Bryce Lewis

    Hey Andy,

    We would love to help you get to the bottom of this, why don't you shoot us an email at support@trainerroad.com. We'll connect you to an agent who can figure out what exactly what is going on with your trainer :)

    Hope to hear from you soon!

  • Avatar
    Dan Canning

    Hi guys,
    I don't have time to do an ftp test at the moment so have been doing workouts at 90% of what my ftp was previously, although this feels about right the tss and .if are always a bit lower than expected so I am just wondering would it be right to just keep adding a couple watts until the workouts start to match the expected tss and .if until I get the time to do another assessment?

    Thanks for your time,
    Dan

  • Avatar
    Darden Mueller

    Hey Dan,

    If you're performing workouts at 90% your TSS and IF wont match the predicted values that are given in the workout summary. These metrics should match up closer if the workout is performed at 100% intensity. Just make sure you're able to complete your workouts and your FTP is set at a number where you're still being challenged during each ride.

    I hope this helps, you can always contact our Support Team at support@trainerroad.com. We'd be happy to answer any additional questions.

  • Avatar
    Paulina Pacyga

    Hey guys.
    First training i put on trainerroad was 20 minutes test, while I has forgotten set virtual power. I have set LTHR but no FTP. Now, when I set virtual power, I have to ride on low intensities,and it is freaking me out :P Should I take FTP test again to have proper FTP on virtual power?

  • Avatar
    Darden Mueller

    Hey Paulina,

    Unfortunately, if power was not recorded during the test there is no way of pulling any power data to calculate an FTP score for you. As for riding at low intensity that sounds pretty strange. Would you mind emailing in to support@trainerroad.com about this one? We can look into this to make sure everything is working properly on your end.

  • Avatar
    David Cochrane

    after completing the ftp test some time ago.....does trainerroad constantly give me a recommended ftp score after every workout or do I need to re take a new ftp test

    David

  • Avatar
    Alexis Borges do Valle

    Regarding the 8 Minute protocol, does TrainerRoad calculate the FTP based on the best of both 8 minute averages, or does it lump both of them together and average that? In other words, if I do a weak first 8 minute test and a strong second one, I would expect my FTP to be based only on the best one... Right?

  • Avatar
    Jakob Christensen

    Hey Alexis,
    We actually take the average of the two intervals. We do this because it's fairly easy for someone to either blow themselves out on the first interval, or have a weak first interval and over-perform in the second interval. Given that 8 minutes is so much shorter than an hour, in order to get an accurate FTP calculation we need to average the two intervals.

  • Avatar
    David Cochrane

    Hi... I asked this question a while ago....after completing the ftp test some time ago.....does trainerroad constantly give me a recommended ftp score after every workout or do I need to re take a new ftp test
    Thanks

    David

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