Heart rate data recorded by the optical sensor of the watch, as exposed to Garmin Health SDK applications.
Moment the message refers to, in UTC. FIT stores it as seconds since the FIT epoch (December 31, 1989, 00:00:00 UTC); decoders usually expose it as a regular date.
Length of the interval covered by each value of the arrays in the message, in seconds.
statusUint8Status of the sensor: 0 while searching for a signal, 1 when locked.
Heart rate for each interval. 0 when no value.
mesgNumStringGlobal message number identifying the kind of message. Decoders use it to know which profile to apply to the data.