Yep. It takes a sample every few hours, but you can also get a HRV measurement on demand by running a session in the Breathe app on the watch. It doesn't tell

Yep. It takes a sample every few hours, but you can also get a HRV measurement on demand by running a session in the Breathe app on the watch. It doesn't tell you anything about HRV in the Breathe app or that it took a new sample for you, but you'll find a new entry in the Health app if you go look right afterward.