I feel like the Half Monty FTP estimator is plain wrong

I did the half Monty in early September and I just redid it now. During the ramp testing in September my max ramp was 320 for the final minute and 333 for a couple of seconds. Today my final minute was 331 for the whole minute and 349 for a few seconds. My calculated results show my FTP went down from 243 to 239. How can that possibly be. This test sucks. I kind of want to give up on this and go back to TrainerRoad. At least I saw consistent increases in my FTP pretty much every test. Here even when I did better my FTP goes down. Its incredibly demoralizing to bust your ass for three months only to find out your fitness regressed.

Isn’t there a 20 minute section where you have to keep your heart rate in a certain range to generate more information that is then used to develop your FTP? Perhaps this affected the calculation as maybe your heart rate was different.


I use full frontal to gauge progress. Half Monty is interesting, but it’s not as accurate.

Also, some days you just test better than others, 2 test results 3 months apart may not be a true indication of how your going.



What power were you asked hold for the 20 minute constrained HR section?

Did you hold that power or did you wander around it? Did you hold the recommended HR during that duration or did you wander around that target?

You have only discussed half the test so no conclusions can be drawn without other information.

I was asked to hold 193 which I did and HR rate was around 151-156 which I held. Couple of times I went up to 157 but then backed off a bit. I also had my third vax two days ago. I was thrilled to see I could hold the power considerably higher than last time. Then I got a punch in the face when I saw the FTP actually went down. Either way I upped the FTP to 255 manually and I am going to keep going.

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Half Monty both overestimates FTP for some people and underestimates it for others. If you search the forum you will see plenty of info about this both from the Coaches and Sports Scientists and users like yourself.

The GOLD standard for testing in SYSTM is Full Frontal. Done properly, you’ll have a very accurate set of metrics for your 5 second, 1 minute, 5 minute and 20 minute efforts. Half Monty is really designed more for a mid-plan check in or for athletes that don’t have as much experience with testing and it’s a less fatiguing (and daunting) test.


@Glen.Coutts Okay that is good to know. I wish they had added the 8 minute test for those who want it. I can go all out for 8 minutes without too much difficulty and I find that it is accurate. Oh well c’est le vie. I still like Systm.


There is CONSTANTLY work going on behind the scenes with testing. Trust me, the SUF Scientists are well aware of the issues with Half Monty, are regularly analyzing the data they get and are working to improve it.

There was a time when the only testing available was Full Frontal and before that, just an ugly FTP test they called Rubber Glove. Not as ugly as Full Frontal (FF is the purest essence of UGLY tests…well that and some of the yoga poses that Abi Carver has us do, but that is a WHOLE nuther story, lol!)

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There’s a reason they don’t have an 8 minute test. There’s lots of info on this forum about FTP tests as well. Most other FTP tests overestimate FTP leading to a value that is too optimistic, one that a cyclist can hold for anywhere from 30 minutes to an hour. But it can vary widely.

Half Monty is designed to determine both your MAP and your FTP. But it has been known to result in numbers that aren’t quite right. To address some of the issues with it, I believe Wahoo’s scientists recently adjusted their algorithms a bit to obtain a closer fit using the empirical data of thousands of cyclists who have taken it so far.

But all tests are educated guesses for durations that aren’t actually ridden, mostly FTP. The truest test would be riding at your maximum effort for an hour. And even that would be suspect, because if you could pedal one more minute at that power level, did you give it your all?

This brings me to a more practical application of any fitness tests, which is simply giving you something tangible to establish both your workout intensities and gauge your progress.

Finally then, when testing protocols (or workouts) are adjusted it can be difficult to gauge our progress. But generally if you are sticking with a solid training plan, you’ll improve. A single test isn’t the ultimate litmus test of progress. Dropping your friends on group rides is one way to validate that your training is working. Not very nice, but it sure is fun. Especially when they are 20 years younger than you!


If your workouts felt less difficult in the final week than in the first then you can assume you’ve made progress. If that’s true rest, recoup and test again.

Vaccination really messed my heart rate up, had to stop my workout 3 days later because my heart rate wouldn’t fall between sprints on violator.

Merry suffering!

You aren’t asked to hold any power for the 20minute section? It gives a suggested power, but it’s more important to keep your heart rate within the prescribed range. I’ve found that I need to pedal a cadence around 10-15 rpm lower than I would for the 20minute effort in full frontal because the HM constrained effort is a sub threshold rather than threshold effort and a lower cadence is more sustainable with a lower HR.

@Claude how did the cadence on your HM compare to last time and the cadence in your last FF?

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For the same power output…higher cadence = higher heart rate.


Yes but the video text does suggests a power level to match your HR

@JGreengrass I kept the HR in the prescribed range. I should have probably pedaled slower. That would have brought my HR way down. I looked at the cadence between the two efforts and it seemed considerably faster this time around during 20 minute test. Oh well. I just upped the FTP from 243 to 255. I went by my increase of the MAP which was +12.

The delta between your old FTP and newer FTP using the ramp test is only 2%. Given that power meters tolerance is 1-2% what you have is within the tolerance. Having seen athletes that I help doing the full 30 minute traditional FTP tests outside they seldom see the same values even when done a week apart.
In short, I take values given to me by FTP tests and…

Measure with a laser
Mark with a crayon
Cut with an axe.

I personally use the Full Monty to get a better indication of the values to use when working out and even then there are days those numbers are easier than they should be and other days I think I inadvertently hit the “+” button on the settings.



My power has been lower and how I feel since I got the vaccine. You may also want to consider that since it sounded like you recently had it ?. I would be curious how you retest in 2-3 months. I’m 10 weeks post vaccine and still with alot of palpitations and not having the same speed for a given perceived exertion.

@wvickers25 As a guy has pretty bad health anxiety…that is the last thing I wanted to hear LOL :slight_smile: The plus is that up’ed my FTP to 255 to from 242 and I did very well on defender which surprised me. After the first interval I quested whether I would able to finish but I did finish strong.

I did the Half Monty today, and knew that my MAP would have likely gone up, as I have been focusing pretty heavily on Vo2 sessions in the past few months. I wasn’t sure whether my FTP would have increased that much, but I am confident that the time I could hold near FTP would be up.

My last test was a FF, which I thought was pretty accurate. Today my MAP went from 311 to 338, and my FTP went from 255 to 281.

I reckon the MAP is pretty right, but I’d be astonished if my FTP is above 265; I’ve been doing my Vo2 sessions at ~ 280. No way am I holding that for 45-60 minutes!


I find cadence makes a huge difference to FTP with HM. If I grind at 70 rpm my power output is much higher during the constrained heart rate period and FTP gets over-estimated by around 10% at best guess. If I spin at around 90 the FTP estimate is around the same as FF.


That is really interesting. I will have to keep it around 90 going forward so that test is always the same.