# 4-7-8 Breathing Pacer

> A visual respiratory pacer designed to stimulate the vagus nerve and restore parasympathetic autonomic balance during acute stress or sensory overload.

URL: https://sensesoverload.com/breathing-478

## Cadence & Clinical Timing
- **Inhale**: 4 seconds (diaphragmatic nasal inhalation)
- **Hold**: 7 seconds (respiratory retention)
- **Exhale**: 8 seconds (prolonged oral exhalation)
- **Automatic Halt**: The pacer automatically halts after exactly 4 cycles and displays a congratulatory vagal reset screen with an option to restart.

## Physiological Mechanics
- **Vagal Nerve Stimulation & HRVB**: Extended exhalation (8 seconds) increases intrathoracic pressure and stimulates aortic and carotid baroreceptors, triggering the vagal brake to slow heart rate and lower systolic blood pressure (Vierra et al. 2022).
- **Alveolar Gas Exchange**: The 7-second breath hold allows maximal oxygen saturation in the bloodstream, counteracting the hyperventilation common in acute panic.