Slow Yogic Breathing and Long-Term Cardiac Autonomic Adaptations: A Pilot Study.

Abstract

To examine whether long-term practice of yogic breathing alters cardiac autonomic control. Age-sex matched, cross-sectional, physiologic pilot study. Spaulding Rehabilitation Hospital, Cardiovascular Laboratory, Cambridge, MA. Twenty-six (26) long-term yoga practitioners and 26 age- and sex-matched controls, free of cardiovascular disease. Cardiac vagal outflow as assessed by respiratory sinus arrhythmia (RSA). During unpaced (spontaneous) breathing, yoga practitioners exhibited augmented RSA compared to controls (yoga 364.8 ± 75.3 vs. 194.7 ± 46.0 ms2Hz-1, p = 0.03). However, during paced breathing at 0.25 Hz (15 breaths/min), which accounts for inter- and intravariability in breath rate, RSA did not differ between groups (yoga 224.8 ± 48.4 vs. 271.3 ± 59.7 ms2Hz-1, p = 0.98). Furthermore, the relationship between age and RSA, such that RSA declines with age, did not qualitatively differ between groups. Long-term practice of yogic slow breathing does not appear to augment cardiac vagal control nor prevent known age-related declines.