Unable to detect Lactate Threshold after 3 attemps - Fenix 5

I would try to run away from trees and in as straight a line as possible - you seem to do a lot of turnarounds. I am suspicious that your MaxHR setting is too low. My MaxHR is set at 193 (and is accurate) but for the LT test I only get to 170. It is not a maximal test.

However your HR is ramping up in a nice slope.

Perhaps you should try a MaxHR test first - 10 min warm up, 10 min above LT, 3 min high effort, 1 min ultra max (and feel very sick at the end).

Have you tried to use the built in Threshold test?

I was able to detect the lactate threshold during my first ever attempt, is your current HR Zone using LTHR?

(10 minutes warm up)
https://connect.garmin.com/modern/activity/2910465499

Hey, thanks all for the advice. Some answers to your questions

- trippyZ my HRMax comes for looking at all my previous workouts using HR monitor and including very tough days, I don't have records over 181. It also includes many Crossfit workouts which tend to give me some good HR peaks. Just for reference these last few days my resting HR is 41 and I use that together with HRMax to set up the zones. In any case I will do a HRMax test.

-the first time I tried I had as HR max 220-age and my issue was that in the last interval of the test I was not able to get to the HR target despite being running as fast as I could.

-meste7 yes, indeed those three attempts were using the built in test

My wife says it could be because the training load was too high those days and I was tired. Should I give it another try after a couple of recovery days? Do you think that will. Make a difference?

New update, in case anyone has an idea of what´s going on.

Today I went for a long run using the HRM and no LT was detected :(. The monitor failed at the end of the run, as you see in the activity graph, my HR droped starting at KM 22 and then disappeared. Could it be that I have low batter? Could that be the reason why I am not getting results? I´ll change the battery and try again

https://connect.garmin.com/modern/activity/2963729780

Thanks
Alvaro

With a long run at an even pace like that, it would be unlikely that you hit your LT, so it is not surprising that no LT was detected.

Low battery seems the most likely explanation for the end-of-run dropouts. But you can check the battery: Settings> Sensors and Accessories> HR> About. (the HRM needs to be connected for about 60 seconds for the battery status to show up.)

I had the same issue! This morning I ran very hard 1200m intervalls and get a LTH of 142 / 4:37 https://connect.garmin.com/modern/activity/2968220603