Peng (2004)

Controlled experimental; physiological measurement; acute effect

Kundalini Yoga Meditation — Heart Rate Dynamics During Three Protocols DESIGN: Within-subjects study of 10 experienced meditators (4F, 6M; mean age 42, range 29-55). THREE MEDITATION PROTOCOLS (sequential): 1. RELAXATION RESPONSE: Slow breathing, silent repetition of a focus word/phrase 2. BREATH OF FIRE: Rapid diaphragmatic breathing (2-3 breaths per second/kapalabhati) 3. SEGMENTED BREATHING: Slow breathing with specific inspiration/expiration patterns MEASUREMENTS: Beat-to-beat heart rate + continuous breathing signals via Holter monitoring. FINDINGS: • Relaxation response and segmented breathing: similar dynamics — high amplitude, low frequency (~0.05-0.1 Hz) oscillations, increased heart-respiratory coherence • Breath of Fire: markedly different — very high frequency oscillations, resembling vigorous exercise • Both relaxation response and segmented breathing increased HR-breathing coherence vs. baseline (p<0.05) NOTE: This is a mechanism/physiology study examining how different KY breathing protocols produce distinct cardiac signatures. Follow-up to Peng 1999.