Breathing Glossary
A comprehensive guide to the terminology used in breathwork, physiology, and respiratory science.
Core Concepts
Diaphragm
The primary muscle of respiration, located below the lungs. shaped like a parachute. When it contracts, it flattens and moves downward, creating a vacuum that pulls air into the lungs (inhalation). Proper diaphragmatic breathing ensures full oxygen exchange, unlike shallow chest breathing.
HRV
Heart Rate VariabilityThe variation in the time interval between consecutive heartbeats. Contrary to popular belief, a healthy heart does not beat like a metronome; its rhythm fluctuates. High HRV indicates a flexible, resilient autonomic nervous system capable of adapting to stress, while low HRV is associated with chronic stress and fatigue.
Respiratory Rate
The number of breaths taken per minute. A typical adult takes 12-20 breaths per minute at rest. Breathwork often aims to lower this rate to roughly 6 breaths per minute (cadence breathing) to optimize gas exchange and trigger the parasympathetic relaxation response.
Pranayama
A Sanskrit term meaning "control of breath" or "extension of life force." It refers to the ancient yogic practice of regulating the breath through specific techniques and patterns to influence physical and mental states. Modern breathwork is largely derived from these millenia-old traditions.
Extended Definitions
Autonomic Nervous System (ANS)
The system controlling bodily functions not consciously directed, such as breathing, heartbeat, and digestive processes. It is divided into the Sympathetic (stress) and Parasympathetic (rest) branches.
Vagus Nerve
The longest cranial nerve, running from the brainstem to the abdomen. It is the main component of the parasympathetic nervous system and acts as the "brake pedal" for stress.
CO2 Tolerance
The body's ability to tolerate carbon dioxide buildup without triggering the urge to breathe. Higher CO2 tolerance generally correlates with better anxiety control and physical endurance.
Bohr Effect
A physiological phenomenon stating that hemoglobin's oxygen binding affinity is inversely related both to acidity and to the concentration of carbon dioxide. Simply: You need CO2 to release Oxygen into your cells.
Sympathetic State
Often called "Fight or Flight." A physiological state of high arousal, increased heart rate, and alertness designed for survival. Chronic activation leads to burnout.
Parasympathetic State
Often called "Rest and Digest." The state where the body repairs tissues, digests food, and recovers energy. Deep breathing activates this state.
Resonance Frequency
The specific breathing rate (usually between 4.5 and 6.5 breaths per minute) at which an individual's HRV is maximized and cardiovascular, respiratory, and blood pressure systems synchronize.
Apnea
Temporary cessation of breathing. "Sleep Apnea" occurs during sleep, but "Email Apnea" is a modern phenomenon where people unconsciously hold their breath while working on screens.
Nitric Oxide (NO)
A gas produced in the paranasal sinuses during nasal breathing. It is a vasodilator (widens blood vessels), antimicrobial, and improves oxygen uptake in the lungs.
Hyperventilation
Breathing at an abnormally rapid rate, leading to low CO2 levels (hypocapnia). This constricts blood vessels, reducing blood flow to the brain and causing dizziness or anxiety.