When my POTS was untreated, I had severe episodes which brought me to my knees and put me into a supine position within minutes. Now everything is different, and it's like learning a new dance after a decade of the same old, same old. How do you know when to quit an activity before it's too late and you've set yourself up for a PEM/flare/replapse? What exactly do you feel when you are at your max and need to stop? I've used a heart rate moniter and pedometer. I would like to hear about what your body tells you because mine no longer speaks my language.