HRM anomalies in Half Monty

I finally faced the boredom and intimidation of a performance test, and rode the Half Monty after a couple of months riding the SYSTM training videos.

During the ramp part of the test, despite the dripping sweat which should have made my Polar HRM more reliable, my heart rate popped up from around 165 (which is appropriate) to 192 then into the 200s, before returning to the appropriate range after a few dozen seconds. I used to get similar anomalies outdoors with a Garmin strap. Did this invalidate any or all of the results???

The cTHR that was reported was 172, which is close to my (assumed) max HR of 175. I haven’t observed anything over 180 in five years. I think this number is not credible. Like everyone else, I am absolutely convinced that I quit the ramp too early because of (insert favorite distraction here), but my MAP increased by only 5 watts, which is credible.

However, my FTP was reported as 262 watts, an increase of 11 percent, which I would say is not believable, but the Sufferfest sessions have been getting noticeably easier lately, so maybe all this science stuff works?!?

So did the HRM issue trash any or all of the results?

Wouldn’t affect MAP, that just uses power, but would likely affect the cTHR and hence FTP calculations as they use the hr data and will be skewed high if that’s over reading. That’s if it’s an hr monitor issue anyway - and if your hr really did spike to well over your max then see a doctor!

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Hello eyeryone I seem to have a similar problem.

First time poster so here is some background about myself. I started structured training with the training plans of Wahoo SYSTM about five weeks ago after buying a Kickr Smart Trainer. For starters I did a Half Monty test to get a baseline for my power and cTHR figures as I never did an FTP test before. I use the Wahoo TICKR as my HR sensor that came with my ELEMNT Bolt head unit.

After completing a Base training plan over the last four weeks I wanted to retest my numbers and did another Half Monty today. The last week was pretty low voulme (5 hr vs. 8 hr in the weeks before) with my biggest ride of the week being the Moon Rider session yesterday.

My recorded HR seemed extremely low during the ramp part of todays Half Monty. Looking at the recorded HR readings after completing the test this was somewhat confirmed:
My peak HR during the Ramp was 145 bpm on the second (!) stage of the ramp. Afterwards it consistently dropped until it hit 94 bpm on stage 8 before rising again up to 138 at the last step of the ramp. In the first test I did it rose consistently to 160 bpm although there were some sharp peaks (174 bpm) and drops inbetween. Compared to the first test I was just about able to complete the last stage so the observed HR in todays test does not feel right.

As a result of the weird HR readings during the ramp my MAP increased by 62 W. Because of the overall low HR during the test the target HR for the constrained HR effort was 20 bpm lower than in my first test (120 bpm vs 140 pbm). At the same time I was doing about 10 W more than in my first test. Still my FTP decreased by 3 W.

I am a bit unsure how to proceed with the new numbers. Looking at the new HR zones there is no way I will be able to match them in upcoming workouts while the older estimation worked pretty well for me (new cTHR is 130 bpm vs. 153 bpm being the old one). I do think my MAP is probably too high now after the second test (managed to complete all steps of the ramp and my HR was fairly low as described above) and my FTP is probably to low (with the low HR baseline the target HR for the constrained effort was very low as described above). What is your suggestion going forward? Keep the values and retest in four to eight weeks, adjust the values, or retest as soon as possible?

My next point of concern is the weird HR reading. As it is so out of place compared to the previous test and previous workouts I assume/ hope it has something to do with the sensor. Any suggestions how to proceed in that regard? Buy a new sensor or just change the strap? I did accidentaly put the strap in the washer two years ago. Could that be the issue?

Sorry for the wall of text. Any help is appreciated.

Thanks a lot

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Something’s def amiss here. A few things. Your Tickr may be glitching (make sure the firmware is updated, the battery is fresh and you can even reset the Tickr by putting the battery in backwards for a few seconds then putting it the right way around).

As for your MAP, if you ran out of steps but could have gone further, or longer, your MAP is probably set a little low (rather than too high as you suggest). But, also, as you suggest your FTP was probably set a bit low too when you set out to do the HM this time.

Given the wonky results, I’d ignore your newly calculated cTHR and use your old one )you can manually input that in settings. I’d probably leave the MAP as calculated and see how some of the rides feel. You could even consider bumping up your FTP and see how rides feel too.

Lastly, you might want to do the Full Frontal at this point. It’s an ugly ugly test but very rewarding to complete. If your Tickr keeps giving you funky readings, reach out to support here:

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I have years of experience with HRM issues outdoors. Make sure the strap is snug. If you have issues when the strap is tight, try using electrode gel and perhaps shaving any chest hair from a strip where the strap contacts your skin. If the temperature is appropriate, don’t wear a jersey - certainly don’t wear a jersey and another layer under it - static electricity can cause weird readings. If you have multiple HRMs, try a different one. My Polar H9 occasionally disappears for several seconds - more frequently indoors than outdoors. My Wahoo TICKR seems more reliable.

I decided to re-run the HM test today or tomorrow, after a week of trying to ride questionable numbers that actually make the discomfort of riding almost as bad as the pain of not riding.

And it doesn’t seem like it would be hard to pre-process the heart rate data to fix, for example, brief spikes on the ramp portion from 170ish to 232 which are obviously artifacts. Any sane correction to the data would yield better results than taking it at face value. And a warning that either something odd happened and the numbers might be a bit iffy or else you should see a doctor quickly. Not such a big deal on Half Monty, that one doesn’t wear me out but does require lightening my riding load the day before, but beating yourself up on a Full Frontal for bogus results is bad suffering, not good suffering.

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Thanks for your input. I will try resetting the HR sensor as suggested and observe the HR closely in the upcoming workouts. I will probably set the cTHR and the FTP back to the original setting. Depending how the intensity feels in upcoming rides I will adjust the FTP accordingly directly in the workouts.

As for the Full Frontal: I honestly am a bit hesitant looking at the power graph. My current All Purpose training plan for the upcoming twelve weeks finishes with a Full Frontal. I hope I am ready by then. In the meantime I scheduled Half Montys every four weeks.

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The HR sensor sensor sits snuckly. The chest shaving bit could be worth a try though :sweat_smile:

It did say on screen that my cTHR is very low compared to the previous value and that this might be due to fatigue. But as outlined in my original post I didnt´t really have a big workload comin up to the test.

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FYI. The MAP number in HM does not depend on HR, only FTP does.

Also, you’re always ready for FF (after a bit of a taper). It will just hurt a lot. But that’s true no matter how fit you are!

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So I re-did Half Monty - had another minor HR monitor issue on the last step even with the TICKR and electrode gel - popped up to 202 from 170, but only for a few seconds, so not gonna screw up averages much. Resulting cTHR is 162 instead of 172, which is exactly what I would have guessed. FTP is 249 instead of 262, which is within one watt of what I would have guessed before the first test. MAP is exactly what it tested at on the first try. I guess hours of staring at performance data builds intuition…

However, having a cTHR which is not 10 bpm too high made the 20 minute constrained section easy instead of a challenge, and the whole thing feels a lot less painful. Half Monty is definitely nothing to be intimidated by.


I also had problems with the garmin heart rate monitor from the kickr core. He has been showing parameters from space for some time. (With recovery - 5 zone and after a while it drops to 1 zone). Replacing the battery several times did not help. I will add that I run with this belt hr and I have no problems. I gave up and use a different old hr belt for Kick core and the problems are gone.

Can you explain what you mean by this? How is the Garmin HRM related to the Kickr?

My point is, one is working (old) and the other (new) is not showing the correct values. They both work on the ant +. I do not know why it is like that.

I was just wondering what this had to do with the Kickr, as you wrote “from the Kickr Core”.

I was trying to figure out if you were trying to connect those two pieces of equipment together or if they were both being connected separately to SYSTM.

I use it separately when using the Wahoo KICKR CORE Trainer. (My English is not very good so I could have expressed myself badly)


For what it’s worth Sir, English is the only language I speak and I still often express myself badly :joy::rofl:

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I hope I didn’t come across as critical of your English (as that was not the intention), I just wanted to make sure that I correctly understood the situation.

Does your “new” HRM correctly connect to anything (SYSTM, your head unit, watch, etc.) when the Kickr Core is not powered?

Does the issue only occur with SYSTM?

You’re right, I wrote it imprecise. So I’ll do it right: my new HRM connects correctly to the watch, Rouvuy or Zwift, but SYSTM has problems at times. (incorrect measuring jumps).
There are no problems with the old HRM anywhere. And that’s strange to me.