How To Calculate Your Functional Threshold Power Without A Power Meter

How To Calculate Your Functional Threshold Power Without A Power Meter

Manon: Power and FTP are big topics here at
GCN, but it’s expensive. You can spend over £3,000 on a new power meter. In this video,
I’m going to show you how to work out your FTP if you don’t have a power meter. Don’t
be under any illusion. It’s far easier to work out your FTP if you do own a power meter,
but I have some tips and tricks to work them out. Here they are.
Firstly, we need to understand what a functional threshold power is. To put it simply, it’s
the highest average power you can hold for an hour. That power is measured in watts.
You can then use the findings to determine your training zones. When it comes to working
out your FTP with a power meter, you can either do it on a static train or on the road. If
you choose to do it on the road, you should try and keep the conditions the same. Do on
the same stretch of road the next time you do it. Once you have decided where you’re
going to do your FTP test, make sure you have a good warm-up before you start the test.
After the warm-up, ride as hard as you can for 20 minutes. Determine the average power
output during this 20 minute period by analyzing the data on the power meter. Multiply your
average power by 0.95 to find out your FTP. There are many ways you can work out your
FTP for free. The first one we’re going to chat about is Zwift. Zwift is offering a 30-day
free trial. This allow you to use their online testing program. All you need is a static
trainer. No need for it to have a power meter in it. Simply a cadence sensor and speed sensor
will be enough to work out your power kit and FTP.
Another way you can work out your FTP is by using Strava. You will need an account, and
you will need to pay for a Strava Summit, which is £18.99 a year. Then from uploading
your rides to Strava, it can give you an estimate of your power FTP.
If you’d rather not pay for Strava but you really wanted to work out your FTP, why not
just write for a maximum sustained effort of 60 minutes, and then upload it to the Strava
free account, and that then will give you an estimate average watts of what power you
did for that hour. Many gyms will have watt bikes in them, or
similar bikes that have power. If you have a gym membership, why not head to the gym
and carry out an FTP test there? If you don’t have a gym membership, you can often find
bike studios. You can pay a small fee and carry out an FTP test there. Although if you
have any friends that have a static trainer with power, why not ask them nicely if you
can borrow it? Another great tool is a bike calculator. The
bike calculator is an engineering model, that is if you supply it with the right information.
It makes predictions about the system. The system is you, the engine. Supplying power
to the three major forces in cycling, gravity, running distance and aerodynamic resistance.
You will need to ride a climb, the steeper the better. The less the wind affects you,
the better and more accurate the power will be. You will need to have a good amount of
information for it to work. Things like rider weight, bike weight, tires, position. gradient,
headwind, distance, temperature, elevation and time. You should be able to get most of
this information from your bike computer. Keep in mind, this is an estimate, and it
will only work if you enter all the details correctly.
Another good option would be to rent a power meter. Now, it’s not free. It is £47 a month.
If you are thinking about getting a power meter and wanting to test one out before you
bought one, this is a great option. If you want to get the most out of your money, why
not do an FTP test every single day of the month? That’d be well fun.
If you’re struggling to work out your FTP, why not try going off heart rate and work
out your functional threshold heart rate? As all you need to do this is a bike computer
and a heart rate monitor. Similar to the FTP test, you just need to carry out a 20-minute
all-out test ideally on a static trainer or on a long climb where there’s no stops or
corners. It is worth noting that usually most athletes don’t see a change in their functional
threshold heart rate over time. If you want to use this test as a way to track improvements,
you’ll have to also record another metric. For example, you could track your average
speed or distance covered in the 20 minutes, so you’ll have something to compare your results
to the next time you repeat the test. Hopefully, this will help you figure out your
power if you don’t have a power meter on your bike. If you like this video, please give
it a big thumbs up. [beep]
In this video, I’m going to tell you some tips and tricks on how to work out your FTP
if you don’t own a power meter or you don’t want to spend a fortune on one, but don’t
be–[laughs] [00:04:31] [END OF AUDIO]

83 thoughts on “How To Calculate Your Functional Threshold Power Without A Power Meter

  1. Do you train with a power meter?

  2. eyy 1st

  3. Second

  4. key is to use the steepest climb you can find, to reduce the impact of the variable of aerodynamics, which is impossible to guess. then run it through some online calculators. rolling resistance is obviously a margin of error, but you shouldnt be off that much, as on a very steep incline gravity is the biggest factor.

  5. Enjoy watching Manon so much. Such a natural presenter.

  6. Question – If I don't have a power meter, what good is it to estimate my FTP? I do a lot of indoor workouts (the GCN ones are great btw) and just use perceived effort and HR zones. Since I can't see my estimated power "live" when riding, how can I really tell if I am at, above, or below my threshold? Is the idea to retest my FTP at intervals and see if my training is increasing it? What is a good interval?

  7. What's the point to know your "not so actual FTP", when you can't use it in training. There are numerous ways to measure fitness, which will be better than that. Instead of buying a fancy lightweight stem for 300 quid, make yourself a favour and grab a real powemeter. It will be hands down the best upgrade on your bike, if you are performence orientated and want to improve.
    Good effort on the video, but still…

  8. Unless you're on the juice you wont ever need a powermeter because youll never perform or win lol

  9. 1:00 What about wind, grade,…

  10. I love the making of each video. Cheeers!!!!

  11. If you don't have a power meter, you can't train to power, so why bother with estimated FTP? Why not set your training zones by heart rate?

  12. Would love to see your review on a velocomp powered V3 as a cheaper alternative. From what I've seen they're about as accurate as you can get without paddles, crank or hub meters. What do you lads and ladies think??

  13. Yeah, you can spend 3k on a power meter…or spend $300. They’re more in reach than ever. If you’re really interested in FTP as a training tool, just get a Stages left side for a few hundred bucks.

  14. Please please please…. stop telling people that ftp last for an hour. You guys are one of, If not the, most influential network in cycling.

  15. Hang on. What’s the point of doing an FTP test when u don’t have a power meter to train with

  16. 3:37 👀👀👀

  17. Last summer i cycled with mtb bike 47 km 1h 27 minutes so 32.6 km/h avg speed i used that bike calculator to get avg watts it was 18 degrees during the trip, zero wind, mtb bike about 12.5 kg and my weight 82 kg my position was bartops but i started timer 2 minutes too early so i lost 2 minutes from the 32.6 kmh avg speed the trip was insane 340 avg watts and my avg heart rate was 156 when my lowest watts record (recovery day trip) it was 23 degrees, zero wind 33.1 km/h avg speed with road bike ( 78 km trip) it was 230 avg watts with only 128 avg heart rate it's pretty insane because the trip lasted like 2h 30 minutes!

  18. Strava Sauce, or some of the other Chrome Add-ons, gives you an estimated FTP, which seems to be only about 3 watts off my real FTP. The Chrome overlays gives a lot of good stats, like W/kg, VAM, 5/10/20/30/1hr power, etc.

  19. Great info and presentation.

  20. To get extra power. I simply break wind. This gives me more thrust ,whilst simultaneously forcing the riders behind me to back off. Win Win all the way.

  21. Can I just get Ollie to tell me how well I'm doing?

  22. Zwift's or similar 0.95×20 min max. power is not real for everybody. At least not for me, as I cannot imagine I could hold that for full hour, which I got from Zwift. Maybe this works for alot stronger athletes. U need to attempt one hour record to have real number of youf ftp 🙂

  23. I want her

  24. I’ve never understood why the average power is multiplied by 0.95. I think that’s way too optimistic…if you really give all that you have for the average on 20 minutes I don’t think is possible to hold 95% of that for a full hour. At least for most of us. True it’s the same method everyone use, but I would have opted for a multiplication factor of 0,85 or there about.

  25. Strava Summit is £48.99 per year, not £18.99

  26. Finally we found Si!!!!!!!

  27. Bullshit

  28. Manon is great 😃 when it comes to explaining anything. She would be a great teacher. Love her

  29. If you don't have a powermeter, no point knowing your FTP power…

  30. I ride for my enjoyment and strength conditioning. To much data take the fun out of riding, speaking for myself. I'm no professional athlete, I ride for the fun of it🙊👍

  31. Yes I do but on trainer Power meter I have 287 in ftp and in the same effort I also used my Garmin pedal power meter and had 266 ftp with them. So now I really not know what power I have :).

  32. You weigh 120 lbs!! perfect! lol

  33. Quarq won’t like this

  34. Nice video Manon. Good ideas on how to calculate your FTP if you are on a budget 😊. Question: I have read somewhere that multiplying your 20 min power by 0.95 (i.e 95%) is just a myth because in reality it is much lower, at least 85%. Although I have not tested it, It sounds logical to me because if I do a max effort for 20 min, I don’t think I will hold 95% of that for 1 hour. What do you think ?

  35. I think doing an FTP test once a day for a month would be dangerous. Personally I go so deep the last five minutes that I almost pass out. Also, reaching maximum heart rate regurarly is not good. Some experts say that only professional athletes should do it.

  36. I calculated my ftp of 240w by climbing a hill which coincidentaly takes about an hour. 6% gradient on average, about 13km. Weigh yourself and your bike, find your tire model on, calculate your rolling drag and use an online calculator for aero drag. The aero drag is low, so any errors in calculation are small.

  37. Many years ago me and my brother looked in the back of the BCF handbook for a coach and paid 20 pounds for him to analyze us whilst we did a test on a bike in his lounge.

    Surely this is the best way to find out your FTP.

    FTP is just a number surely it's better to paid for all the advice as well as being told what this magic FTP number is, the advice will probably be worth more the the FTP number.

  38. 1:16 – since when Zwift offers 30 day free trial? Or am I missing something?

  39. rider weight 120kg? No schitzels anymore!

  40. Why do I need to know my ftp if I do not have a power meter really……
    You must practice WITH a power meter around your ftp…

  41. Without even walking out to my bicycle, I can tell you my FTP. It's pathetic.

  42. Strava's power estimation is complete crap. It once estimated my avg power over a 1.5 hour race to be 440 watts – I wish! Why try to obtain your FTP when you don't have a PM afterwards to make sure you're training in the right zones? If you're unable to afford a power meter, train to RPE. I have a PM & I find I pace my TTs better when I ride to RPE than power anyway. You can get really in tune with your body & hit the right-ish zones you need to for training with RPE.

  43. I wouldn’t trust a power figure from the free version of Strava – mine varies by about 95w depending on which bike I nominate, i.e. 8kg road bike or 12kg commuter bike, when I go as hard as I can on both on the same 1hr route.

  44. Seriously though what’s the point if you don’t have the meter. Of late your really clutching at straws, repeats and the lamest content. What has happened since Matt and Emma and Si have left. Even Opie is missing.

  45. Pro tip: buy a power meter

  46. I use a static "dumb" trainer that doesn't have a power meter BUT, I found out that most trainers have a chart that you can find online that calculates watts per mile per hour or KPH (in the hardest setting of resistance). This is where Zwift gets there information even if you don't have a smart trainer. So all I do for my 20 minute test is ride as hard as I can for 20 minutes after a warm up and see what my average speed was. Then I look on the chart to see what power I was putting out at that average speed. Does anyone else use this method?

  47. Thumbs down. Please don't use this advise. HR really ? It's affected by weather ,sleep , coffee ,food. It keeps dropping as you ride longer like multi days. It's ok but definitely not as helpful as power meter .

  48. Greetings from Philippines🚴

  49. i dont have any friends.

  50. A lot of gyms have a spin bike with a power meter. Just get a day pass and use their spin bike for 5 bucks. My local gym has that, and I figure all my stats with that.

  51. The calculator program is WAY out. I used data from Vegan cyclist's videos (he's a big guy like me).
    I got a carpenter's inclinometer from Canadian Tire to measure grade. A nearby hill is signposted at 15% but is actually 20%.

  52. This woman always sounds like she's just eaten a large spoon of peanut butter right before her segments begin

  53. Others have already said it, but if you don’t have a power meter, there’s no point in figuring out your FTP.

    Also, I’ve had the dual sided Assioma power meter pedals for a year. They make a single sided version that’s even cheaper. They only cost in the hundreds, have worked great, and are plenty good enough for the vast majority of people. And because they are a pedal system, one set can be used on all your bikes and also measure the power where it’s most applicable to the effort you are putting out.

  54. Since when does FTHR not improve with training (3:57)? I understand the limitations of measuring and training to FTHR, but I don’t understand why one’s heart rate at threshold wouldn’t drop as one becomes fitter.

  55. I can't ride as hard as I can for 20 mins, lol. Going full gas I might last 5. Do you ride has hard as you can sustain for 20 minutes, or just burn out and ride slower once your legs are jelly? Not all of us are pros!

  56. At 3:36, uhm…


  57. Why not?

  58. I'm watching your video but idont have a bike

  59. Were poor

  60. She keeps getting better

  61. 95% of 20min is far far away from FTP for most of the people… It is somewhere between 85-95%

  62. Video idea! A video explaining the different formats of track racing e.g. Elimination, Pursuit etc 🙂 I'm sure that will go down a treat ahead of the new track series GCN will be streaming?

  63. I would really Like a " how to" Series for absolute beginners! There are so many Details you cant Figure out as a beginner….strava, komoot, Training Apps…how to sync with your bike computer..and so on.
    My first roadbike and the garmin arrive on monday – so, hurry up😂

  64. Has anyone tried running a bicycle on a chassis dynamometer (used for motorcycles)? They are usually better calibrated but will measure power at the wheel.

  65. Where's Si ? 😞😞☹

  66. FTP is overrated.

  67. You can also just make up your FTP number out of thin air.. It's what I do. #151RULES!!!!💪

  68. Great Laugh at the very end

  69. Recently, I tried one hour max effort and it is harder than all those faster tests. But most of all, some "short effort" zwifters might be suprised about the difference in the FTP value.

  70. Q) How To Calculate Your Functional Threshold Power Without A Power Meter

    A) Use a power meter

    Thanks. That was really helpful.

  71. Don't have to worry about power ,got SFA 😅

  72. Great presentation from Manon but just buy a cheap power meter if you're reasonably committed cyclist.

  73. I train with HR and intuition. From time to time I do 1h flat ride with strava and watch their calcutions. If they are systemtically incresing it means that my form does as well. I pay 0$ and get knowledge whether I improve over time. I only dont have real time power estimates but they are not Worth for me right now. I can feel in legs when I push zone 2 or zone 4 or zone 6.

  74. I bought second hand Elite Turbo Muin trainer with additional Misuro b+ sensor last September. Did 20 min FTP test. Trained for about 5+hours/week. Repeated FTP test in December but did 1hour test that time. Changed bearings in January which made it a bit easier to pedal – FTP will be different, I guess.
    Since I bought this trainer I have 130hours on it. It does not measure real power, it is just an estimate.
    Even though I spent some good amount of time on the trainer looking at the numbers, I just can't say what power output I produce. I can only guess in 20-50w range. I can say I do easy enough, moderately or around FTP or more.

    So, I see no point of knowing your FTP just for the number not being able to use it during each and every training. To know my FTP and train just by feelings misses the point of structured training completely.

    I just agree with other guys, here. Buy powermeter.

  75. Zwift power is the best… depending on what I set my trainer resistance I got a FTP between 207 and 392 (Done on the same bike, same trainer, same sensors with the ramp test) – which one could I take as a serious estimate? Sure the 392 one is pure ego, spinning resistance 1 and the 207 is stomping on pedals, on a resistance too great than I can handle.
    Don't get me wrong, I enjoy Zwift and I even did part of some of the training plans, all this because it got me used to pedal indoors, and I do enjoy to customize my avatar as in any video game. But I still don't understand how someone could train to power if they know their "estimated" FTP and not have a concrete way of measuring it in real time, you could do with indoor rides, but I think anyone could agree that cycling is better with people outside than staring at a screen between 4 walls.
    I don't own a power meter but I've been saving up to buy one and I'm dying to see how "close" these estimated watts are…
    Not to take anything away from Manon who is doing a great job and it suits her quite well as a presenter… but this video basically says "know your FTP so you can have something to wave your prick around to people about".

  76. Computer based applications use the same basic ride data that the bike calculator uses to work out your power curve / speed. Likewise, if you put in incorrect data you get free Zwift speed!!! In-fact, the bike calculator is probably the most accurate as you not the software program selects the specific ride dynamics………. it all just basic physics. Anyway as someone else mentioned below, if you don't have a power meter you don't need an FTP, Doh !!!!!!

  77. Strava also gives average power over any interval for free accounts. Just use the Analysis tool or define your private segment.

  78. One would use these methods if they dont have an FTP. however estimating an FTP is useless if one doesnt have a power meter to train with. Sorry, So why bother with this video?


  80. You can also use a garmin and Power Bike Field and get it live

  81. Knowing your ftp is only useful if you train with power, if you don't have a power meter and train with power what is the point of working out your ftp. I'm confused..

  82. If you're interested in improving and want to measure that improvement then buy a power meter. Second hand dual sided will cost 3 or 4 hundred which isn't a lot if you are serious about improving.

  83. What kind of bike and groupset is that lady riding?

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