I am just trying to get into running. I purchased a Forerunner 305 so
I could try to use my heartrate as an indicator for pace etc. I want
to get started by alternating walking and running.

Can anyone help me to understand how you can set up the unit so that
as I am running, if my heartrate reaches a certain level, it will beep
at me notifying me to walk. Once it gets to a lower level point, I'll
know to start running again. I'd like it to continue with this until
I am done with my session.

If it wasn't clear,
Start and run until heartrate reaches ~170 and the unit beeps at me
Walk until the unit drops to about 140 and the unit beeps at me
Run until 170, etc

I'd appreciate the help.

Thanks.