UserProfile.restingHeartRate - what watches is it available on?

(I'm using the 2.1.0 SDK and my va-hr has the 2.71 beta with the 2.1.0 VM)

I get a "simulated" value in the sim, but on the watch, it's always 0. Just wondered if anyone has tried it on other watches, and was wondering if there and should a valid restingHeartRate.

TIA