Automatic detection of anaerobic threshold

Today after a bike workout, the garmin updated my heart rate threshold, while Interval did not. Having said that, it is obvious that the 2 systems calculate the updating of a new threshold in a different way. The question is: how does Intervals do it? And would it be possible to make it as similar to the Garmin one, so that the two are updated in sync?

As far as I know you need to manually update the heart rate zones in Interval. For cycling FTP it will detect the new FTP based on estimated FTP for a ride, but I do not think it does this for heart rate.

No, it also does it for the heart rate, but only with a constant effort of 20 '. I know because he notified me twice about a new threshold after making long climbs last year.

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I see. I think I have my zones set by the max heart rate only. And if I get a new max heart rate Interval.icu assumes it is due to measurement noise. Thus, I have to manually adjust it.

Intervals.icu will notify you when it thinks your LTHR has gone up using 98% of 20m highest average HR. It doesn’t change your zones automatically because it might have been hot or you dropped your bottle and got thirsty etc etc… So you need to make the call.

Garmin allows you to manually change your LTHR as well as Max, depending on what you have it set as.

I would only change mine, or my athlete’s, if they (1) did a 20-minute all out effort (it’s actually 30 minutes with the last 20 being used), and (2) if they achieved the same in a race under similar conditions. Repeatability is key to ensure consistent results in testing.

I would then ensure all apps are updated together to ensure consistency across platforms.

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The new detection of Intervals only occurs when it is greater than the one set, or even if it is less? My Edge 530 found the threshold with an effort of about 13 minutes. Would it be possible to find the threshold in Itervals even with efforts shorter than 20 '(as Garmin does) or would this be too unreliable?

I am not sure. I went with 98% of 20m after reading some blog posts and so on. You can always look at your ride and just manually decide to update LTHR.

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Took me a to figure out that I had a Auto HR Setting on Garmin Edge 830 ( equal to 530 except for the touch screen ) and it was constantly changing my zones, specially on Z2 +Z3 and making me crazy during training ( low effort, seemed like Z2, power was right and it showed Z3 near sweetspot ).

So i tried to disable all the auto features ( need to dig the menus ) and will check weekly for that.

The point I want to raise is that Garmin will hardcode the zones in the FIT file and not let you update those after ( I’ve searched for this ) so you start having a data mess where each platform says something diferent like this example :

Top left Garmin with Auto and weird zones
Down Left Intervals
Down Right Strava

Hope this helps, took me almost a month to understand !

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