When people search for how to stimulate the vagus nerve, they are often looking for one thing: a way to feel calmer in their own body. Maybe your breathing feels shallow. Maybe stress sits in your chest. Maybe your nervous system feels “on” even when nothing urgent is happening. Or

Heart rate variability, usually called HRV, has become one of the most talked about numbers in smart rings, watches, recovery trackers, and stress apps. You may see it in your Oura Ring, WHOOP, Garmin, Fitbit, Apple Watch, or another wearable and wonder: What is optimal HRV? Is my HRV good