The Physiological Sigh: The Two-Breath Reset Your Nervous System Already Knows
When stress spikes, your body already has a built-in brake — a double-inhale, long-exhale pattern that offloads CO2 faster than any calming technique on record. This is the science of the physiological sigh, why it outperforms box breathing for acute stress, how it maps onto the Stoic discipline of assent, and a 7-day protocol for making it your default response to every spike.