Andrew Huberman· PhD
You don't want to take this physical exercise that I'm talking about to exhaustion, because that's going to leave you depleted. That's going to cause an uptick in parasympathetic activity. Any of you that have done a hard leg workout, and then, you know, two, three hours later, you're just like... It's very clear, brain oxygen levels are down, parasympathetic activity is up, you are tired because you exhausted all that energy in exercise.