Why is the intensity minutes feature failing recently?

Did the Resting HR change recently? You can find the evolution of the RHR on the page https://connect.garmin.com/modern/report/60/wellness/last_four_weeks 

If it is higher now than it used to be, then that is the likely reason, since by default the Intensity threshold is based on the Resting HR.

Hi,

Thank you for sharing. The report shows a stable situation in a 47-52 bpm bandwith, and last weeks average was 2bpm lower than the 4 weeks average. The one year number os 52 bpm

A 50 minutes steady 100 bpm heartrate exercise this morning did not result in any intesity minutes. 

Which device did you use for recording the activity?

Fenix5X
Which I have been using for long time now

Could you post screenshots of the HR graph of the activity, and also the HR graph from the Daily Summary (all-day HR)? Like that we can see whether there were any periods longer than 10 minutes with the HR above the threshold without any interruption. If the HR dropped, even just for a few seconds below the threshold, there are no IMs awarded for that, at Fenix 5 (unlike at many newer models).

Also, in the settings for Intensity Minutes, do you use the default setting, or did you assign HR zones for that purpose?

I did not record the walking activity seperately, but I trust you see it in the graph.

The treadmil rund of 26 minutes that you see on the same graph did result in 34 total intensity minutes, ie 22 moderate and 6 vigorous.

but 

Where do I check the settings for Intensity Minutes?

Well, the screenshot is missing the scale on the left, but since the peak on the right side of the ~1 hr long walk shows only 79 bpm, and the remainder of that walk is even lower than that (with the exception of the brief starting peak), I think it is more that probable that the HR simply did not surpass the Intensity threshold (which is roughly 150-160% of the Resting HR, hence around 75 bpm) for more than 10 minutes.

JanD said:

Where do I check the settings for Intensity Minutes?

I am not familiar with F5, and it is possible that it has no settings for that at all, but on newer models it can be found under Health & Wellness

Thank you for your assessment!  Really appreciate your analysis here  

I add the below screenshot with scale for your information  I guess there may be heart rate drops during the walk but that cannot be concluded from the graph  

I keep struggling with the concept that the walk did not generate intensity minutes whereas the treadmill exercise did result in intensity minutes

There seems to be some logic missing in the algorithm or the graphs do not represent the activity accurately in terms of impact on intensity calculations 

it did work consistently for a long period though and these abnormal results only happen to me recently  

JanD said:

I add the below screenshot with scale for your information  I guess there may be heart rate drops during the walk but that cannot be concluded from the graph  

You can zoom the graph to just the 1 hr section, to see it better. Either with two fingers on the app, or by selecting the interval with a mouse on the web interface, preferably on the full screen graph. And you can hold and drag the cursor to see the exact values. As long as there is no section longer than 10 minutes with the HR above the Intensity threshold, there will be no intensity Minutes.

And indeed from the little I can see on the graph, without having the direct access to it, there does not see to be any interval > 10 min with the HR above some 75 bpm. The starting peak is interrupted briefly, and the rising end is far too low to trigger any IMs, on my mind. Only you yourself can verify the exact values and times, but on the first look I'd tell that getting no IMs for that walk is justified.

Besides that, the watch records the HR with the interval of 2 minutes, while in real-time it samples the HR every 15s. The algorithm counts the IMs in real-time using the 15s samples, not the 2 minutes averages.

JanD said:

There seems to be some logic missing in the algorithm or the graphs do not represent the activity accurately in terms of impact on intensity calculations 

Not sure what you mean, but the logic of counting the IMs is explained for example in the article How Are Intensity Minutes Earned? | Garmin Customer Support. And if you want to see when exactly you gained some IMs, then have a look on the IM timeline in Garmin Connect Web. For today it would be at https://connect.garmin.com/modern/daily-summary/2023-09-01/intensityMinutes 

I also have problem.

Yesterday, and today, I've taken my bike to work in the same way I have done for years.

Then yesterday evening I noticed that there are no intensity minutes in my clock. When transfering the activities to Garmin Connect in my phone there is nothing there either.

When I look at the pulse charts for my cycling acitivities they look the same for this week and previous week. Max pulse and pulse zones are correct. Well, or at least they are the same as they always have been :-)

I restarted the clock. Didn't help.

I can't see any plausible reason why the intensity minutes don't show. Any ideas?