Dfa alpha 1 in Xert ebc

@ManofSteele, nice article in pezcycling (How To Use Heart Rate Variability DURING Training – PezCycling News) on using dfa 1 for zone 1 training.

You managed to convince me to cough up the cash and try the hrvlogger app. It turned out my zone 1 was close (-10w) to my LTP, which i was impressed with despite testing on an outdoor ride. Fortunately I ride the same outdoor route 2x every day, so it’s going to be interesting to see how consistent that is over the course of a week, and over time with fitness.

So im now left wondering, is it wishful to think your article is a sign that a DFA alpha 1 field will be coming to xert ebc in the near future?

I sure hope so, as it’s a pain switching between the two apps (xert + hrvlog), and I don’t want to have to choose which one gets sole rights to my bluetooth hrm on zone 1 rides!

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If you have the Polar H10 then it has dual Bluetooth streams. You have to turn the 2nd one in in the Polar app.


Hi @Jarradk ,

Thanks for reading my article! I hope you found it interesting and useful as you start experimenting with DFAa1!

At this time, no. The articles I write for Pez are typically related to (relatively) newer research studies that I find interesting. I think DFAa1 is one of the hotter topics in endurance sports right now, so figured it would be a good topic for the article. There are no plans at the moment to include any form of DFAa1 monitoring directly in Xert EBC or Xert Online. Seems most folks are using the HRVLogger or Runalyze to do some of the analysis with DFAa1.

As @carytb mentioned, there is a setting in the Polar app to duplicate the H10’s Bluetooth signal so you can pair to two apps simultaneously.


Just wondering if anyone has successfully used the HRVlogger app with a Garmin Dual HRM? I got the app yesterday, did a test last night and again this morning using the protocol in the article and alpha -1 drops below .5 by the end of the 10 minute warm up!

I suspect something must be wrong as the wattage is waaayyy below my all day pace , which can mean up to 10 hours plus on occasions. It’s roughly about 70 watts below LTP and drops to around .3 about 100 watts below TP, so that can’t realistically be correct.

Does seem unusual, maybe check the artifacts removed chart for evidence of anomalies?

I am on garmin dual and my 0.75 alpha is around 10-20w below LTP, but it fluctuates a bit from day to day.

I can get strange results if it’s within the first 0-15m of my ride where I haven’t got sweaty enough for a good/stable hrm reading, so I generally turn off the app and restart it later into the ride.

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Very likely there are errors in the raw HRM data. Be sure you have the R-R interval correction set to ‘Workout’

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Yes, I made sure that was selected along with 2 minutes for the duration. I’m giving the strap a wash now and will change the battery to see if that makes a difference. Something is off as my TP is 299, LTP 259 in Xert yet I’m below. 75 by less than 180w.

Jarrod, thank you so much for posting this topic. The links within the PEZ article are themselves well done in my view, e.g., the commentary having to do with apparent increasing validity of the STRYD device, as well as those others that describe the very many sensors that can also be used. I had no idea it was possible to assess muscle oxygenation w/o invasive measurement.

FWIW, I got HRV Logger and I’m using it with my dual-band Garmin. BAM. Flawless data acquisition. I’m now trying to figure out how to mount my iPhone and my iPad so that i have concurrent displays of metrics available from the Logger as well as EBC.

Again, thank you very much, Anthony

I also get results all over the place despite controlling for all recommended aspects… HRV is sensitive to many things (time of day, fatigue, caffeine) and people’s baselines are also very different. Some of those things may be dealt with by the detrended fluctuation analysis (don’t know the math) but suspect not everything is given variability if results. The whole thing is still really developmental, so would take with a grain of salt. The papers I’ve seen so far are really anecdotal I.e. one to two people, and I’ve seen coaches commenting on other forums that they wouldn’t rely on it at this stage due to mixed results.

Personally, for LT1, I would just stick to something like 90% LTP or the talk test to go old school