Ralphirvine1 - Tap on the heart rate tracker screen, rotate the bezel to select Auto HR settings, and then
select the option you want, in this case Always: Your heart rate will be automatically measured continuously, regardless of your movement.
However, while I find this reports better sleep patterns I almost never register any deep sleep with always on. When I change back to every 10 minutes I suddenly get deep sleep 
Ive now just set it to always and just see how I feel when I get up in the morning, usually my head tells me if Ive had deep sleep or not 
