Base runs being recorded as Tempo

Thanks very much. I’ll conduct another LTH test ASAP and see if that changes anything. I have LT auto detect turned off now. Once I do the test should I accept the new value?

The other consideration that I had with my runs is that, because I live at the base of foothills, most of my long runs mean that I go down for an extended period of time (half my run) and then a gentle incline back for the second half. Not sure whether that would have any bearing on things?

My recommendation is to do first a manual field test for the HR Max. Do it after plenty of rest. In the end, we talk about pushing the heart to the highest possible so it will be a very hard workout. If you can do more at the end, you didn't push enough. As mentioned above, a 5k at your max is a good way to get an (easier to get) estimate. Plus, who knows, you might get a new 5k PB!

After the HR Max is confirmed, do the LTHR built in test and use it to update your zones.

I don't think that the elevation that you show in you screenshot should be an issue. 

Ok. Got you. Thanks for all your input - it’s super helpful. 

I’ll report back my MaxHR after going for my PB 5km. Once I do this should I alter the settings in the watch before doing the LTHR?

chris.clements said:

Once I do this should I alter the settings in the watch before doing the LTHR?

Yes, enter your HR Max in your heart rate zones and disable the auto-detection.

Check out this post where we discuss LTHR and LT pace detection accuracy.

forums.garmin.com/.../1699150

Okay, so I just ran a 5km all out. My max HR was 190. The auto detect feature was in for my half marathon in October where it detected my Max HR at 196. If I take your rule of +5 bpm it seems to be pretty accurate. 

Here is the kicker. My time today for 5km was 19:06. My watch predicted 20:11 and even just now still predicts 20:09.

I suspect the error lies within my lactate threshold recording which was last taken back in June which was  4:41/km at 169bpm. What are your thoughts?

chris.clements said:

If I take your rule of +5 bpm it seems to be pretty accurate.

Indeed.

chris.clements said:

Here is the kicker. My time today for 5km was 19:06. My watch predicted 20:11 and even just now still predicts 20:09.

Yeah the race predictions use a bunch of data (VO2 Max, recent history) and your last race is just one new data point. My race predictions are a bit too optimistic if I input a specific race, and much more optimistic for a generic, ideal 5k. That said my results fall in the range of error that Stryd's prediction tells me, but that Garmin doesn't disclose. 

chris.clements said:

I suspect the error lies within my lactate threshold recording which was last taken back in June which was  4:41/km at 169bpm

Exactly, now that you have a high confidence in the HR Max, the next suspect is the LT data. There are 2 sides of it: the HR and the pace.

The heart rate side of it should be accurate with the built in LTHR test (less with the auto-detection).

The pace side of it is probably more complicated. We don't know how that pace value is picked. Some traditional method that 95% of the speed for a 20mn maximum steady effort. It is unlikely that is the actual pace at the time of detection.

I think the watch is using the HR/pace relationship that it models. That relationship is modeled based on your training data.

While the model works well even with sub-maximal efforts, it is better to feed the watch with maximal efforts with the concept that "measured" is better than "predicted".

One way to feed maximal efforts is to follow the DSW and, maybe once every few weeks, replace the target pace with the fastest pace you can maintain steady for all intervals in the workout. This is what I do for anaerobic and threshold workouts. 

chris.clements said:

Unfortunately it has the slightest of inclines at one point . I suspect this is why I failed the test

Looking at the elevation, I doubt it. If I read the graph right, we are talking about 10m of elevation changes.

chris.clements said:

I really struggled to keep the HR in parameters

What do you mean? The HR graph looks OK. This is a graph of my HR in my last test, Maybe your pace was not very regular during the first step, but then it is hitting the target pretty well.

I am stumped that the LT was not detected. Is there any chance that the HRM is not working properly? Battery? Old strap?

How did you do your last LT in June? With the same set up?

It looks like the peak HR of the test was pretty high? What was it? In my test, it didn't go higher than low 150's which is about 13 bpm lower than my HR Max.

Yes you are correct. There wouldn’t have been more than 10m of elevation changes between laps of the oval. There were probably 4 times that my watch alerted me that my HR was too high. From memory the test went something along the lines of:

2 x 4min 136-152

1 x 4min 152-164

1 x 4min 164-174

1 x 3 min 174-182

1 x 3min 182-194

I’m not 100% sure on exactly those bpm but it’s pretty close. I was annoyed at having to run that last portion only to find Lactate TH not detected! Haha. I was pretty gassed. Max heart rate detected was 193bpm which was higher than the 5km I did earlier in the week. 

I have wondered about the HRM myself. I only recently replaced the battery because it kept dropping out on my Fenix 5. For the most part it seems to find a pretty steady HR. Occasionally on the more vigorous runs it might report a really low HR in the low 80’s or 90’s. I’m not sure if it’s Because of poor placement or contact. I think it may be maybe 5-6 years old.. though it could even be a bit older than that. I’m not exactly sure which Garmin product it came with!

Have you ever had a LT test or detection completed with this strap?