Self-regulation is one of the five domains of emotional intelligence, and it is also one of the most physiologically grounded. It is not a mindset. It is a skill with measurable biological markers, and breath is one of the most direct access points we have to it. When the body perceives stress, the sympathetic nervous system activates. Cortisol rises. Breathing becomes shallow and rapid, which compounds the stress response rather than interrupting it. What most people do not