Does anyone know?
Charles check this video out it may help. I had to watch part of it a few times when he talks about recovery strategies but the table is in the book as well.
Just to correct your original statement. If yor receive a negative HRV score, this means that your body is further away from homeostasis than your most recent readings. It does not necessarily mean you are having a large vagal response. If you are having a large vagal response, then the lowering of your heart rate during expiration will be of greater magnitude. Specifically, this means during relaxation, you are OVER-relaxing; probably as a result of over-stimulus.
Additionally, a positive reading simply means that you are more homeostatic than your most recent readings, not that you are in a sympathetic (excitatory) state.
Look at an HRV reading of 10 as homeostasis; the further you are away from 10 (theoretically), the more stressed your physiology is. This could be because of a vagal, or excitatory response.
I just bought HRV and the book! Wow what a fire hose of information. I have a question though. I gathered that if your numbers are Pos you are Parasympathetic at the time and if there negative you are Sympathetic dominant then. Is there a quick reference sheet or way to remember how to handle a -Amber or Red vs a +Amber or Red?
If not that would be a great addition to the resources here.