Zone 2 with a machine that can keep a constant rate is a big vagus nerve stimulation. You should not be out of breath but you should also not be at rest. Stair master is my preference. Try it and see how you feel before and after. Use the HR on the machine to dial it in.
Who has good experiences with vagal nerve stimulators?
What’s your experience been?
What brands do you use?
Is this our parasympathetic solution to the battle we are losing against the sympathetic?