Definitionv1
Physiological sigh: a breathing technique involving a double
Physiological sigh: a breathing technique involving a double inhale through the nose followed by an extended exhale through the mouth that maximally inflates alveoli and triggers parasympathetic activation through CO2 offloading
Why This Is a Definition
This definition precisely specifies what constitutes a 'physiological sigh' by detailing its mechanism (double inhale + extended exhale), its physiological effects (maximal alveolar inflation + CO2 offloading), and its functional outcome (parasympathetic activation). It differentiates this technique from other breathing protocols and establishes its specific neurobiological basis.