Continuous HR registration from external sensor possible?

> Try it....

Strange, I have indeed tried it with an HRM-Tri over several devices with hundreds of activities (that were not swims) and never seen this issue. The only time I would need to "download" the HR data is the odd time I do a swim.

Perhaps you can post some GC links to such activities to further illustrate your point.

I am aware of some Connect IQ data fields that allow to record both OHR and HR data from a strap but recall it has to take the OHR as the "primary" source. Are you using anything like this?

As I mentioned I am now aware of any significant impact on battery life.

> Try it....

Strange, I have indeed tried it with an HRM-Tri over several devices with hundreds of activities (that were not swims) and never seen this issue. The only time I would need to "download" the HR data is the odd time I do a swim.

My experience exaclty.

I just want to confirm I am talking about a Forerunner 935 using version 6.0 firmware.
For a Swim activity when you select save, the watch automatically checks for the Swim strap and will download HR data from it.
For other saved activities eg Run/Bike/Walk to download HR data from the Tri strap you need to manually select the option "Download Heart Rate" (within that activity).
Until you select this option you have OHR data saved.

In fact you can store an activity twice on Garmin Connect, one with OHR data and one with HR data from a strap.
Sync the saved activity before downloading HR data from the strap.
Select the option to download the HR data from the strap and then Sync again.
I have to admit that I have only done this once or twice by mistake.

I am unaware of any Connect IQ data fields that allow recording of both OHR and HR data.

You can still "download" the HR data if already paired to an HRM-Run/Tri/Swim. Can you post some GC links to when you think you only got OHR data despite being paired to a HR strap in say a run or ride.

These HR straps will record HR data even if not paired. The download, as you say, makes more sense in that scenario. Are you 100% sure that the HR strap was paired to the 935 before starting. I suspect it was not.

Sorry for the delay in replying.
I am concerned about privacy in posting a GC link. Maybe you could advise on this.
At present the only GC items worth a look at are on another subject related to OHR (WHR) data for my saved Walk Activities.
The data is crazy but this is another subject and I have just received my new replacement 935; replaced because of the bad OHR data.

Today I finished a Run Activity and saved it.
As usual I saw the connected to HR strap post followed by the connected to satellite post before starting the activity.
When I saved the run activity my TE data was something like 3.2 and 3.1 (Aerobic and non-aerobic) after loading HR data from the strap it changed to 2.8 and 2.0 respectively.
Max HR and Avg HR were unchanged and but the calories reading increased.

When I get a chance I will try and save a run activity on GC twice ie before and after the download of HR data from the strap.
My guess is the before will contain OHR data.

One problem I have when wearing a HR strap and with OHR data active is when I look at a HR reading I have no idea whether HR is from the strap or the optical sensor.

Understand the privacy concerns but equally it is very difficult on a public forum to offer any meaningful advice when nobody else has reported this issue and we can't see what you are seeing (i.e. some actual data).

I think you may need to contact Garmin support.

While not giving my links to GC I will report on an experiment.
Yesterday I did a 55km bike ride with the Tri strap on and connected.
On stopping the ride activity I saved it to GC BEFORE executing Download Heart Rate from the Tri strap.
I then executed Download Heart Rate (about an hour or so later) and saved a second instance of the activity to GC.

Comparing the two instances saved to GC I noticed the HR plots looked the same but there were differences when toggling between the plots.
Despite that both plots had an average HR of 93 and Max HR was 123bpm (OK you may think I was bludging but it didn't feel like it).
But the other noticeable differences were:
Calories burned were 674C before download and 820C after.
Training Effect Aerobic/Anaerobic were 1.4/0.0 and 0.8/0.0 after.
I did not notice any other differences but that is not to say there were none.

Today I did a 6.18km run in sand dunes with the Tri strap on and connected.
On stopping the Run activity I saved it to GC BEFORE executing Download Heart Rate from the Tri strap.
I then executed Download Heart Rate (a few hours later) and saved a second instance of the Run activity to GC.

Comparing the two instances saved to GC I noticed the HR plots looked pretty much the same though again I did not examine them forensically.
But there were a few other noticeable differences:
Calories burned were 575C before download and 627C after.
Average HR was 124bpm before download and 125bpm after.
Max HR was 143bpm before download and 144bpm after.
Training Effect Aerobic/Anaerobic were 3.8/1.2 and 2.9/2.0 after.
Again I did not notice any other differences but that is not to say there were none.

What is going on?

I do know from experience that the HR straps will still transmit (in this case record as well) for some time after they are removed. Quite how long that might be I don't know, but I'm sure someone could tell you.

> What is going on?
Seemingly not recording OHR when you had paired to a HRM-Tri as you originally suggested was happening. In other words it seems like you are more or less just replacing the same data.

Why calories and TE values differ is less clear. Which do you believe more? Maybe it is because the recorded HR data is just that and so there is some difference in how it handles the processing of HRV data in either case. Another factor is that perhaps it has just "learnt" about you from the "standard" one and anything coming along afterwards is then seen as more "ordinary" and marked down a bit for TE.

From what you said however, there does not seem to be an obvious reason to do the "Download HR" going forwards.