HR while swimming with wrist worn external device

In my opinion the real reason why the built-in HR it is disabled during swimming is beyond the "accuracy under water" or "Garmin wanting to sell you another gadget", it really boils down to the format pool swims are recorded in. They're unlike any other activity when you have a time line that records different sensors values through time, where every second or so you have a gps value, an hr value, elevation etc, pool swims are more counting how many times the device senses a sudden change of acceleration like the push from the wall as lap, then saves the current time and calculated pace based on how long since the last one. It really isn't compatible with the way HR is recorded, Garmin would have to change their platform to support this, instead they decided to come up with a "clever" idea that also provides them with another source of income, record the HR in a separated specially designed device and have it shown together in their app and website.

You can see that even using the HRM-Swim the hr values aren't really attached to the activity but shown together, when websites such as Strava or Swim.com pull the activity they don't get the HR data.

On the other hand, if you record an Open Water swim with a Mio Link or any other wrist based HRM next to the watch it will not only show the HR data during the activity but also record it and attach it to it, this is because the open water swim is recorded pretty much the same way than a run, based on GPS locations through time which fits perfectly the HR readings. I assume they disabled the built-in HRM during open water swims to keep it consistent but it does work with an external one unlike the indoors swimming.

To change the format on which the pool swims are recorded will require significant work on their part considering all the legacy devices.

I use the Fenix 5 in Cardio mode with the OHR and it works decently. Better have it a bit too tight than too loose. I prefer to have estimated HR than nothing (nothing is still more wrong than an estimate).
During the first laps you have to do some laps without moving the arm so that the watch takes the heart reate rythm after that you can swim normaly.
I feel it's really a pitty that the OHR is deactivated in swim mode but anyway I prefer to count my laps manually.

Here is the HR chart. As you can see, at the beginning the HR is wrong (too low) but then its catches the HR except between 31 and 36 min where it's lost again. I did some HIIT at the end and it recorded it properly.ciq.forums.garmin.com/.../1247636.png

Just a thought (I don't pool swim that often, so haven't been able to test it out), but does anyone know how the CIQ Aux HR behave during pool swimming? https://apps.garmin.com/en-US/apps/88ce4547-7d84-4289-b2c7-3e15ca00185f Whilst this isn't a solution to using the Fenix 5's WHR during pool swims, it might at least give access to Mio or Scosche HR in real time during pool swimming (not sure how it would record to the fit file given previous comments).

Considering the 788-post forum posts where people moan about the GPS showing them on the wrong side of the road or an inch away from where they think they were, I'm not at all surprised that Garmin doesn't want to entertain the logic of "slightly wrong numbers are better than no numbers".

I accidentaly discovered how to show OHR during pool swimming. I managed to lost my HRM-Swim belt which worked great. So last couple of trainings I've done the swims without HR data recording.

I started the pool swim activity as usual, only without HR-Swim belt. During the activity hold Down button which brings you to the default watch face (the activity still going on). Scroll down to the HR widget (it has to be enabled in non sport mode obviously). You should see your OHR. Now if you press Back button and go back to your swimming sport mode the OHR is displayed! And of course it is way off compared to my HRM-swim data.

I don't know whether it is a bug. Software v8.00

I accidentaly discovered how to show OHR during pool swimming. I managed to lost my HRM-Swim belt which worked great. So last couple of trainings I've done the swims without HR data recording.

I started the pool swim activity as usual, only without HR-Swim belt. During the activity hold Down button which brings you to the default watch face (the activity still going on). Scroll down to the HR widget (it has to be enabled in non sport mode obviously). You should see your OHR. Now if you press Back button and go back to your swimming sport mode the OHR is displayed! And of course it is way off compared to my HRM-swim data.

I don't know whether it is a bug. Software v8.00

I have tried this thing long time ago, so it's not related to 8.00, however, hr doesn't record into fit file...

I have tried this thing long time ago, so it's not related to 8.00, however, hr doesn't record into fit file...

It's a pity....
:(

Don't get a Mio Fuse or Vivosmart etc. because the whole reason that the Fenix doesn't record HR while swimming is it is grossly inaccurate and the same holds true for them. Tiny bits of water refract the green light in weird ways between your skin and the camera and cause the view of the bloodflow to be messed up and it doesn't record accurate numbers. You can trick a Fenix 3HR (and I assume a 5) into recording in the water by putting it in run mode (obviously won't record strokes) and you'll see the HR will be very messed up. DCRainmaker did a bunch of tests, the results were useless HR for most of the swimming. Occasionally it would be accurate for short times but then go way off track.

The *only* way to get accurate HR in water is a chest strap.

Half of true, Fenix line is too heavy and bulky so while you swim watch gets quite heavy restrictions from the water and watch moves, I have test Suunto Spartan sport and Garmin 5 with hrm swim and suunto was only 5-3 beats off and average hr only 2-3beats off, so it is possible when designed correctly, suunto is much more lighter watch and sensor placement is very good.