The New Science of Breath proposes a revolutionary theory of health based on autonomic nervous sytem balance - via breathing. Eastern cultures have held breathing in high esteem for thousands of years; references to its importance are to be found in some of civilization's earliest writings. Yet even today, while modern biological and medical sciences have made great strides in exploring and understanding the details of the human organism, including respiration at the cellular level, beyond gas exchange, the larger biological function of breathing remains something of a mystery and is generally taken for granted. The New Science of Breath introduces Coherent Breathing, an exciting approach to health enhancement. It is based on the premise that while at rest the adult cardiopulmonary system, inclusive of autonomic nervous system aspects, resonates at a specific frequency, this frequency being essentially the same for all adults. When the breathing frequency is consciously aligned with this "reference rhythm" with appropriate depth, it results in optimal autonomic nervous system balance. Autonomic nervous system balance yields mental and physical comfort, a positive emotional outlook, enhanced health and well-being, and improved biometrics.