Yog, Stress and Systemic Regulation: A Narrative Review

Stress-related disorders, both physical and mental, are rising globally and call for integrative models of care. Rooted in Indian philosophy, yog has long been recognized as a path to balance and well-being, yet modern research often reduces it to a relaxation technique. This review takes a broader perspective by examining yog-based breath practices through the lens of vagal modulation-a central mechanism connecting the autonomic, endocrine, and immune systems. Drawing on psychology, physiology, and psychoneuroimmunology, it highlights three measurable outcomes of vagal regulation: heart rate variability (HRV), cortisol, and inflammation markers. Evidence indicates that breath practices enhance HRV, restore adaptive cortisol rhythms, and reduce inflammatory activity via pathways such as the cholinergic anti-inflammatory reflex. These findings support yog as a systemic intervention promoting homeostasis and balance. For scholars of yog, this clarifies how ancient practices regulate stress through biological pathways and for scientists, it underscores yog’s relevance as a biologically grounded, low-cost, and accessible healthcare tool. The review concludes with the concept of samatvam (equanimity) – balance amidst stress/chaos from the Bhagavad Gita, presenting yog as both a philosophical ideal and a physiological reality.