Quick FTP calculation question

I hate doing the ramp test - I’m a bit of an outlier in that it doesn’t give me good training numbers at all, so I tend to do a 20 minute test or a full on hour effort, usually on zwift. Today I was planning to do a 20 minute test using Alpe du Zwift, but ended up riding the whole thing. Averaged 361 watts for 42 minutes. What do you all think I should update my FTP to? I’m thinking about 350-353.

Edit - I’ve been training with FTP set to 345 for the last 8 weeks or so

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Seems reasonable - issue will possibly be repeatability if you are testing for improvement. But if you are just using it to set your training zones, I would be happy with that. Only thing to be careful about is that the effort was steady, without a surge at the end as you outsprinted Van Der Poel!

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350 seems low to me. I’d use 360.

I am 95% certain that your FTP is between 312 and 385 watts.


350 is pretty safe but it depends on how it felt. If it felt steady state and sustainable, it might be 360.

But you won’t miss out on much by setting it at 350 and it might be better anyway.


FTP is the power you can hold at maximal lactate steady state. TTE is usually between 40-70mins. Doesn’t that mean your FTP is at least 361?

Bit lower is always safer than a bit higher


Not if he weighs 72 kg, but ok if he weighs 70 kg! :wink:

It really depends on the situation.

Going to try for PR that will take longer than 40 min. Starting conservative is good.

For doing TR catalog workouts that are threshold or lower? 360 should be just about right for a but the most extreme threshold ones.

Doing VO2? Cant really peg it that easily off of FTP anyways. It might be 120% of 350 or 117% of 360. Same difference in the end.


@danielrsharp Slight increase in the last minute racing for the line, but nothing too dramatic and a pretty steady effort overall (well, as steady as I could make it given the varying gradient of Alpe du Zwift).
Normally I would do the Ven-Top course on zwift as a test - somewhere between a 1hr and 1hr10min effort and round up the average watts to get a rough FTP. It’s not the most consistent testing protocol, but I use it more as a guide that I will then adjust based on how the next couple of weeks of TR workouts feel.

@stevemz That’s pretty much what I’m thinking. I’ll adjust up or down based on how the next couple of weeks of TR workouts feel

@paulgrav I think if the climb had continued for another 10 minutes my wattage would have started to fall a bit, so setting it at 361 might be a bit ambitious. Hopefully I’ll be up there after the next TR block


Sounds like you have a healthy relationship with your FTP, not always the case on here!


I would go with 255w

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Hi Paul

I am in a similar boat if only because I am curious. I did Alpe d’Zwift yesterday and rode at an average of 357W for 47’39". Did you find any additional source that would suggest, for example, a probable % of your FTP for a 45’ effort?

The ramp test has worked well for me so far in terms of effort required by the workouts and also improvements yielded. At the beginning of build phase, the ramp test estimated an FTP of 344W. The Alpe effort was on the last day of Build phase before the rest week.

your FTP is 357…

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I ended up using 355 which, based on the next couple of weeks worth of workouts, felt just about right. The ramp test really doesn’t work for me at all but I’ve got a pretty good handle on how various different types of workouts should feel if the FTP level is set right, so I’m pretty good at adjusting it to a good enough level. I’d say take a couple of percent off then see how things feel. If you’re struggling with workouts, knock a little bit more off. If you’re finding things a bit too easy, as a bit more on. If the ramp test works well for you, then that would always be my starting point as its a standardised protocol.

Sadly illness and injury has knocked my fitness back a long way since the heady days of 350+ FTP - went down to about 300, so I’m slowly building back up again.

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The ramp test doesn’t suit me either although it does seems representative of my poor/ worn out day performances. On a good day I can far out perform it (my 25miler/ 40km PB back in May was circa 70w more and other TT’s and well paced 20mins tests have been similar). Post my operation (and 3inch shorter bowel/colon) my performances can vary a bit though so I’ve set my FTP half way between. I’m maybe undertraining but hopefully AT when its ever released will address that :thinking:

I’m on the AT beta at the moment and it definitely has its advantages. Where you find a workout easy it will adjust future similar workouts to slightly harder versions. Likewise, if you find a workout particularly hard, it will adjust down future ones. The really annoying thing about it at the moment for me is that if you manually adjust your FTP it screws up all the workout levels, which negatively impacts its selection of workouts. Hopefully that will be improved in time and by the time of the proper release will be fully sorted

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Thanks @paulrattew :slight_smile:

I am happy with the ramp test as a basis for workout difficulty. I just wondered if there were some kind of formula to arrive at an estimation of one’s FTP based on an all out effort of whatever length between 20’ and 60’. A couple of years ago, I took part in a BSc study at our university’s department of sports and exercise science. The participants needed to do a 20’ FTP, CP and ramp test (I am not quite sure if there also was an 8’ FTP test) to estimate FTP/60’ power. The results of all tests were within a reasonable margin of error or what I would expect as day-to-day variation in my case. While the study design could probably be improved in a couple of ways, it was quite reassuring.

This week is recovery week and next Tuesday I will do a ramp test before the speciality block. It will be interesting to see if the result is closer to the last ramp test (344W) at the beginning of build phase or the Alpe effort (357W).

I am not 100% sure of the formulae but Intervals.icu calculates your eFTP based on whatever length of effort you feel is appropriate. I think Alex at Fast Fitness Tips has a similar spread sheet to calculate FTP from max efforts.

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