The original Fenix 5 series did not have the HR on the stock watch faces. I'm not sure if there are any 3rd party watch faces for the F5's that do that nor do I know if they plan on adding that functionality in the future.
Lots of 3rd party watch faces do have HR. I was using GearMin until the battery drain issues on firmware 9.20. I know there is a beta that 'fixes' the issue, but for now I'm avoiding the 3rd party stuff.
A number of CIQ watch faces display HR, and some update it every second or so. I've have some that do the "second or so". and most of mine can do it very minute.
Simple Heart does the the "about every second" for example, and 6-8-10 Fields, near 1sec HR can be any one of the fields.
I posted about this recently in 5+ forums. I have both 5 and 5+ so I can do a direct comparison. Yes, the stock watchfaces on 5+ series have HR as an option for datafield. No, the original 5 series does not have this. I searched for it multiple times. ;-) There's couple other cosmetic changes to datafields (barometer now displays not only trend but actual pressure for example), but this one is by far the most significant. It also updates every second.
I'd believe this could easily be added in firmware update to the original series. But as others said, there are connectIQ watchfaces that do it now.
