“Practices that increase vagal tone (measured by heart rate variability, HRV): - Pranayama (alternate nostril breathing, 10 min/day — directly stimulates vagus nerve) - Cold water on face (activates dive reflex → vagal activation, 30 seconds cold water on face/neck) - Humming/chanting (Om chanting, Gayatri Mantra — vibrates vagus nerve through laryngeal muscles) - Slow exhale breathing (inhale 4 counts, exhale 8 counts — long exhale activates parasympathetic) - Yoga (inversions, forward folds — increase venous return, stimulate baroreceptors → vagal activation)”