Lactate threshold test not working - always "workout ended, threshold not found"

So you don't have a clue as to what your maximum heart rate is? Maybe your setting is way too low?

I'm almost 66 with 190 bpm for HR max and my threshold test had me running 4 min @ 155 bpm, 4 min @ 165 bpm and then stopped at 3 min @ 175 bpm when it said it detected the threshold.

66 with 190 - wow! well the old 220-age has me at 165 - but that's why i wanted to do the test, to find out more accurately what it is. you suggesting bumping it up further than the 170 I tried? will give it a go and see what happens - thanks

HRmax is best tested, not calculated. If your healthy do a good warm up, then all-out intervals and see at which HR you end up. Make sure not to use a single beat as HRmax but the one for a few seconds. My calculated one is 172, the real one 186. With better technical skills HRmax increased over the last years.

I have never been close to that calculation. Mine has come by actual that has been obtained, so it may be a little low yet as everything I've read tells me true max is really, really , really hard to obtain... I looked in my Connect/watch settings this morning and see my Max now at 194. I guess it has changed over time.

As @5082041 mentions, best not to guess...

well, i'm trying not to guess, which is why i'm doing the lactate threshold test. i just haven't been able to make it successful. once i have, won't the watch set my max hr accordingly (per some formula)?

I have the same problem.

Eventually sometimes I get a threshold value, but the most of the time I get the same as you: "workout ended, threshold not found". The last time I tried on a track, and it couldn't find a threshold even if I was always in the heart rate green zone. I gave up and I don't do threshold test any more. When I do my training sessions, I wear sometimes the chest strap and I hope that it updates the threshold value, but it never happens. Now I have a threshold value two months old.

There is no working formula for HRmax, formula equals guessing. HRmax you reach is anyway sports specific. Either chance it and set it to 190 or better test it. It's even better to invest a few bucks and have it tested in a lab, then you get LT1, LT2 and HRmax and the real VO2max all at once.

Hello,
i do have the same problem - now!

In September i did the test. And it works well.
1. Step Target 131bpm
2. Step Target 144bpm
3. Step Target 153bpm
4. Step Target 162bpm and in 3/4 i couldn't hold the pace anymore, test finished
Threshold Puls: 155bpm with 4:37min/km Pace
all good.

Today after a lot training, i feel and i know i am much more fit:
1. Step Target 131bpm
2. Step Target 144bpm
3. Step Target 153bpm
4. Step Target 162bpm 
5. Step Target 171bpm i couldn't hold the pace anymore, test finished
BUT THIS TIME: COUDN´T FIND A THRESHOLD :-(

Same problem here. It was working in November.

I tried a LT test in Jan and was unable to even get close and felt like I wasn't really rested enough to perform as was needed. Later in Fed (About a month later) I did a LT test and it worked.  9:23 min/mi @ 173 bpm

1 Target 145 bpm

2 Target 160 bpm

3 Target 169 bpm

4 Target 179 bpm

I guess you have to meet certain criteria