From the test ride yesterday I have
I registered on Runalyze.
So I will run both RR’s through Runalyze and export a1 to csv. Then I have 4 streams of a1 values to compare.
FWIW: a quick run of the original FIT through Runalyze gave me 100% Valid and 0.2% artefacts on the H10 RR data.
woot!! 
Quite Possibly your HRM is not providing good HRV data. (Guessing)
Looking at your DFAa1 data which starts out at 1.8 but your average shows 0.86a1. (but it’s loads better than how mine look)
Maybe consider putting your FIT file into RunAnalyze and into their DFAa1 analysis and see how many are valid RRs?
So I made a comparison Fatmaxxer vs Runalyze (from Garmin recorded HRV) vs AlphaHRV IQ app.
Fatmaxxer comes in a csv file.
The activity Fit file was analysed in Runalyze and I exported csv from the DFA-a1 chart.
AlphaHRV app result was taken from intervals streams.csv
First the Runalyze result
Now all 3 plotted in LibreOffice Calc
Fatmaxxer received RR data from Polar H10 over one BLE channel
The Garmin unit over the second BLE channel
The IQ app over ANT+
Runalyze reports 0.2% artefacts. Fatmaxxer logged 42 artefacts over an hour at an avg heartbeat of 128, or less then 0.5%.
For me, this confirms that the usability of the DFA-a1 is very dependent on the combo of HRM, Recording device and software app. The number of RR artefacts must be realy low to get something meaningfull.
I absolutely love Fatmaxxer because of its extra tools.
There are limitations:
That last one is the reason I want to use the AlphaHRV IQ app, but only when it gives similar results. This test shows that the app is as good as ready.
Have you read this?
Could this explain partly what you are experiencing with DFA-a1?
I concur. My morning workout, my HR “froze” in some instances and I ended up w/ some flatline HR. No way HR is at 120bpm when > 150% FTP and thus may give a clue as to why my AlphaHRV data was a bust
Would be interesting to see the IQ App on BLE and Garmin on ANT+ to see if the trend is the same as opposed to what Marco Altini saw whereby BLE has better signal.
The other thing is also that FatMaxxer uses the Polar SDK which provides the uVolt ECG signal strength. I’m pretty sure that no such SDK exists for usage in Garmin CIQ data fields.
interesting…
As opposed to @MedTechCD’s data he showed above, (His is showing 100% valid,0.2% Artifact, yours is 64% Valid and 2.5% artifact)
But both of you guys are using the H10.
So… the conclusion is - no idea ¯_(ツ)_/¯
Maybe @Luisma_Gallego_Soy_P is correct. It’s really is finicky and has dependents on more variables (out in the real world)
… the extracystole is here (red circle)
no correction in the alphaHRV app (DFA Alpha1 drops to 0.4)
corrcted in runalyze (in my opinion, DFA Alpha1 stays at around 0.75)
What was the app version?
I’m pretty sure the app will detect those now. Version 0.9.9 filtered every artefact that was flagged by Fatmaxxer in my last test.
Up till 0.9.6 that was not the case, altough 0.9.6 was the first version announced to correct artefacts.
aaah ok … yeah my app version is 0.9.5, so i got to test this… thanks!
… by the way … anybody of you has heart extracystoles (no artefacts) which you can perfectly see in the HRV-recordings?
Still have been at the doctors and everything should be ok so far with my heart. But they say extracystoles are “normal”.
Had to look that up.
Extrasystole: A premature contraction of the heart that is independent of the normal rhythm of the heart and that arises in response to an impulse in some part of the heart other than the normal impulse from the sinoatrial (SA) node.
I’m not an MD so please don’t take this as any form of advice, but I work in related environments as a service engineer and what I hear is that they are NOT normal. They are usually harmless when they come in low numbers (something like <25% of the normal beats). They can be very uncomfortable and when in high quantity, cause heart problems.
I would suggest to consult a cardiologist when in doubt.
I’m scheduled for a gas exchange test in a couple of weeks. Something I do on an almost yearly base, just because there are educational congresses organised by my employer. The room is full af cardiologists, pneumologists and physiologists and they need 1 or 2 guys to perform a VO2max test. I’m one of the regular volunteers. That gives me a free of charge checkup for my heart and some solid numbers for VO2max, VT1, VT2, …
Thanks for your response.
I would say i have here and there extrasystoles during exercise, sometimes not even one sometimes 2-5. Outside an activity it’s hard to say, but i would guess 10-20 the whole day - so far away from <25%.
I still had a ECG under rest and one on a bike ergometer, plus an heart ultrasound scan.
So the doctor says everything is ok so far, but unfortunately at the doctor - of course - i had no extrasystole on ECG.
I just added a 0.75 line to the DFA a1 chart.
Dfa a1 gives me completely wrong results. According to DFA A1 I have LT1 in Z4 
Runanalyze also gives me the same results.
Sorry @david , I got a little lost, problem with the language. To obtain the DFA a1 and Epoc what should I use? AlphaHRV or other app? only with bike?
