Recording heart rate in smartwatch mode with chest strap monitor instead of wrist heart rate monitor

You need to start an activity. Otherwise, it'll disconnect the chest strap to save power. Just make a simple activity with GPS and other sensors except HRM strap off, and record. You can try deleting the activity and maybe the heart rate data will stay in the daily info.

HR info from a HR strap that is recorded during an activity that is then discarded DOES stay on your metrics from my experience and therefore will count towards active minutes and body battery and so forth. I do this frequently for another reason. Just make sure like sis said to turn off your GPS and other sensors to not kill your battery every day.

And one more note.... I assume you are wearing scrubs. Would putting it around your ankle work as it is concealed by the scrubs? If so if you put it on your inside leg just above the ankle there is a good pulse point there that will work and then u get steps with HR and everything. Try it first to see.... it works on my leg but I have insanely skinny ankles and the vein shows easily.

Thank you both for the quick reply. I tried it yesterday and my heart rate is still on my metrics. Unfortunately it did not measure stress in that time, do you know if there's an opportunity to measure it while recording an activity? The activity is still on my watch though, are the metrics still available if I delete the activity on my watch?

I think the watch disregards stress during an activity (regardless of whether it comes from the onboard OHR or an external chest strap), on the assumption that stress during exercise will be through the roof. 

It's activity-dependent. Yoga and Breathwork still have stress metrics during the activity, maybe some others do as well.

However, it has a bug, when you are using an external HR sensor in Yoga for example, the stress metrics cannot be seen and not recorded in the activity. On the 24/7 tracker however, you can see the results so this bug does not affect to your case.

I tried it with a yoga activity and the chest strap. It did measure a lot of stress for the whole activity while I was sitting down and having a relaxed day. I noticed that the green wrist laser was blinking all the time, maybe the stress has to be measured via the wrist?

Did you have PulseOx switched on? Perhaps that's why?

No, I switched that off from the beginning

Ah - perhaps use the Jacket Mode power settings for that activity to disable wrist HR. I've not seen it come on for me with a strap.... But, the Yoga activity may be different?