To check accuracy of the a1 values from AlphaHRV app, you need an app that uses the Kubios Std way of calculating. Every app is getting compared with Kubios to check the accuracy.
In your case, you could check against AIEndurance or Runalayze. Don’t know if you need/have subscription.
In the case of the IQ app, it is important because the Kubios calculation can’t be done on most head units/watches. Not enough processing power. That’s why there are some attempts to do preprocessing with other filters that are less demanding in processing power.
i will check if the RR stream from the app is stored in the FIT because if it is, I could run it through Fatmaxxer and create a second Feature file from that data. Then I can compare the original a1 from Fatmaxxer with the post ride calculated one from the app. Fatmaxxer accepts RR streams in csv format to reanalyze.
Artefact correction is considered “the easy part”
And of course, if you can avoid artefacts, that’s the best way. But I do have an APC every now and then. And I’m having a lot of trouble sitting still on my bike to avoid movement artefacts. I almost always have a couple artefacts on a 1 hour ride.
Thanks for the interest all of you are showing on alphaHRV. It’s still a beta app and I am working hard to provide a final fully validated version as soon as possible.
It’s not easy to make real time DFA in a Garmin device.
Feedback from all current users is being really helpful to reach the goal asap
I have checked the fit file from Garmin and I think the RR stream is included in the fit file, in a separate section named HRV. Would be great if anybody having access to one of the mentioned tools with Kubios calculation to verify the quality of alphaHRV data field on Garmin devices.
@David is there anything on your ToDo list to implement DFA calculation in intervals directly if the RR stream is included in the source (.fit) file?
I am a colleague and collaborator of Íñigo Tolosa, I have been doing many tests with DFA for more than 7 months and comparing it with laboratory tests, we have done fatigue tests and I have been studying the “physiology” of alpha-1 for quite some time.
I have been doing physical training with volunteers for 7 months and I have obtained spectacular results. You have to be clear about how to use alpha-1 and how to extract the thresholds, you can’t extract them with a normal training, you have to do a special test with a watts stability, otherwise the data could be wrong.
If you have any questions please do not hesitate to contact me.
If the developer of intervals wants to incorporate the detection of thresholds I am willing to collaborate with him in the methodology and in the use of script.
I think I know the answer will be no but here goes anyway…is there a way of getting the data into an Edge 520 to get the data onto a post ride chart in intervals.icu? By that I mean even via a download of a csv from Fatmaxxer or HRVLogger.
Not everyone is following up on this thread as actively as I do, so I’ll make a quick wrap-up to avoid confusion.
The RR stream in the HRV field from the FIT file is the one recorded by the Garmin itself when the option is enabled in the settings of your unit. Coming from the source that is paired as a std HRM, be it BLE or ANT+.
I don’t know yet if the AlphaHRV IQ app records its own RR stream though and if it is, where it resides. I sure hope it’s not overwriting the HRV field… The a1 value is for sure in another dev field and already displayed in Garmin Connect and Intervals. Edit: The RR from the app is not in the FIT file. Tested on version 0.9.9
If both RR streams were available in the FIT, that would make it very easy to compare signal quality between BLE and ANT+. The app has 2 fields in the dev section: Alpha1 Raw and Alpha1. I have no idea what the RAW means
Post-ride calculation of DFA-a1 in Intervals is already on david’s todo list and will probably use the code from Fatmaxxer because it’s the easiest one to integrate (Java)
I think that a post-ride analysis should be done the Kubios way (smoothness priors filter) because Kubios remains the goto software for this analysis. Post-ride means that it will be done on a desktop, tablet or phone and these devices have enough processing power to do it.
AlphaHRV is a blessing when it comes to real-time calculation and display of the a1 metric. It’s much easier to have it directly on your sports-unit iso. running on a seperate phone. It can be very helpfull to keep you at the correct intensity on outdoor Z2 rides. It’s no big problem if it is slightly off and let’s be honest, it will never exactly match the other apps simply because it has not only another preprocessing filter but also another measuring window (200 beats iso 2 min)
Determining tresholds is another story. I’m already using a1 for a couple of months during indoor rides where I have Fatmaxxer running on my phone. I know my VT1 point pretty well now. I’m not using it for VT2 though. Still I think that tresholds should be determined post-ride after following a good protocol for this kind of thing. And that is still a debate. Ramp or step, increase per step, step duration, … But then again, why determine tresholds in bpm or Watts if you can have a1 in realtime? Just use a1 directly during your Z2 rides for intensity discipline and you will not be dependent on tresholds that need retesting when your FTP has grown or your fitness has improved and VT1 was pushed up.
I don’t believe this is possible with the native settings on the 20 series, only on the 30 series. For example, I just checked the 520 owners manual online and there is no reference to HRV capability, whereas if I check the 530 owners manual there is reference (as follows):
Ah yes I remember seeing this a while back, not sure if I got around to trying it, will do so now. Need to brush up on how to get a fit file into ICU rather than relying on a Strava dump, must be fairly simple I guess. Plus I will need to use my head unit indoors which I rarely do being a Trainerroad user. Thanks
520plus is on the compatibility list of the IQ app.
It can’t hurt to try the fit file, nothing will go wrong. It either reveals the setting or it does nothing.
I follow Bruce Rogers 6 min long intervals and set Fatmaxxer to 5 sec sampling, the risk is starting at too low a power and the session becoming too long
Ah ok. 520 is probably not IQ compatible while 520plus is?
If you applied the fit and the setting “Record HRV” became available, then you should have the RR stream in your activity Fit file. You can check that in Intervals by going to the activity interval data page and downloading the csv streams file. It should have a column titled HRV and values 670:685…
You will not be able to do anything with it right now but when the a1 calculation comes to Intervals, you will have post-ride analysis.
I gave up trying to do this on a ramp protocol. I just started riding (on the trainer) at 60% ftp after a warmup and followed a1 live with Fatmaxxer. Increased bit by bit after getting a somewhat stable value untill a1 was hoovering around 0.75.
Now, when I ride endurance i completely ignore the first 15min because in my case a1 needs about 10-15min before it gets stable and then set resistance to 72% FTP which is usualy close to my VT1 and a1 around 0.8-0.85. Then I adjust resistance accordingly because an endurance ride the day after a VO2max is not the same as after a rest day…
I’m in the minority here, but I think the real-time alpha1 is not very useful. As an athlete, you should get to know how it feels to approach and cross over VT1. Doing low-intensity work is perfect for developing this skill.
The most important thing, if you want to use alpha1, is to get reliable data. And I’m not convince that ConnectIQ app is there yet.
If you already record rr intervals, then you can analyze alpha1 post-ride, for free, with Golden Cheetah and Runalyze. Those two tools have been very reliable and flexible. I prefer Bluetooth over Ant+, but collect rr intervals on Fenix5 and Fenix3, but only really analyze the Fenix5 data. I’ve used Kubios, Artiifact, and tried RHRV and other open-source tools.
If you use the Golden Cheetah script, you get a regression from pace, power, and heart rate. Runalyze does a regression, too and also allows you to export alpha1 to csv for further analyses.
I check alpha1 after every ride and run with a chart based on Marco Altini’s script. I’ve compared alpha1 to blood lactate samples and it seems to work well. But people should read the paper and understand that using 0.75 arbitrarily is not the way to go.
