Heart rate not available after swim activity

After a swim activity I notice that my heart rate data is not available. The data is available in Strava and Garmin connect and with other activities it is always available but with swimming it goes wrong.

I tried to export it and upload it manually but the tcx file contains not the pace and the fit file does not contain the heart rate. But both are available in Strava and Garmin connect.

I made my activities public so you can check it:


I would expect that the heart rate chart was available and I think is a bug.

I did upload it now also manually so that could maybe mess up things for debugging but the heart rate chart was never available for this activity (other activities is does work properly)

Perhaps I did something wrong. But hopefully someone can check this and let me know.

Can you get the original .fit file from the device? I had a look at the .fit file you uploaded and it doesn’t appear to contain any HR data.

I hope this works, I cannot on my phone upload anything else then images on the forum (perhaps it is my mobile browser)

Fit file from Garmin connect:


Tcx file from Garmin connect:


My data is recorded with a Garmin device and synced to Garmin connect. Garmin connect did also the sync to Strava (that also contains all the data)

If I look in the fit file viewer I think I also don’t see my heart rate data but I guess you are better in reading those files then I :D. When I export it from Garmin to a tcx I do get the heart rate but not the pace data.

The file you linked is the same as the one I downloaded from Intervals.icu. I can’t figure out where the HR data is hidden. I will poke around some more.

I opened your file in Golden Cheetah and the HR data came through. Just need to figure out how it is stored.

intersting because it is the same device i use for any other activity where it does work. It is a garmin descent nk1.

Tonight i will do another swim so i have another file for reference. What i hope to do tomorrow is to compare the fit file from cycling and swimming and to see if they look different but it so sad it is a binary file and a xml or something :frowning:

swim tonight. discovered that HR isn’t show in intervals.icu
i can only see zones calculated pace in per 100m speed.
garmin connect has no issues with data
stava seems to has HR data but i aren’t a subscriber anymore.

is there any users show hr after swim activity?

I do have HR in my swims but i have the ignore option on because it’s an awful data (Open water) anyway, see if you have in the charts options the HR on

I will have a look at this. Not sure why the HR trace isn’t showing up.

I have a similar issue with a timed activity recorded with the Garmin HRM-Pro heart-rate monitor. Garmin Connect shows all HR data, but it seems that intervals.icu only show only HR data recorded while the HRM-Pro was in range with the watch (i.e. begin and end of the session).

Quickly looking at the FIT file (through Garmin FIT CSV Tool), I can see HR data in “record” messages and I think that’s data reported by intervals.icu. Other HR data (not showed) are in “hr” messages (filtered_bpm field).


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Tx for this. Hopefully I can get at that data.

I think there is a description on how to access the data with the Garmin SDK (section “Using the HrToRecordMesgBroadcast Plugin”): Cookbook | FIT SDK | Garmin Developers

I think I have this sorted. Your file worked and another older one. Tx for all the hints!

Old activities can be fixed by doing Action → Reprocess file. The activity list view is also handy for finding all swims and reprocessing them:

I confirm it works. I can see the complete HR recording after doing Reprocess file.
That’s great, thank you very much for the quick solution.

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