Diaphragmatic breathing, also known as deep or belly breathing, involves the conscious use of the diaphragm, the large dome-shaped muscle located below the lungs, to control and regulate the breath. When you inhale deeply, the diaphragm contracts and moves downward, allowing the lungs to expand and fill with air. This type of breathing is in contrast to shallow chest breathing, where the breath is primarily restricted to the upper chest.
One of the key connections between diaphragmatic breathing and the body's physiological response lies in the vagus nerve. The vagus nerve, also known as the tenth cranial nerve, is the longest and most complex of the cranial nerves. It extends from the brainstem down to the abdomen, innervating various organs along the way, including the heart, lungs, and digestive system.
The vagus nerve plays a critical role in regulating the body's parasympathetic nervous system, which is responsible for the "rest and digest" response, promoting relaxation, digestion, and recovery. Activation of the vagus nerve leads to a decrease in heart rate, blood pressure, and stress hormone levels.
When we engage in diaphragmatic breathing, the movement of the diaphragm stimulates the vagus nerve, triggering the parasympathetic response. This, in turn, leads to a cascade of physiological changes in the body, including:
1. Reduced heart rate: Deep breathing activates the vagus nerve, causing the heart rate to slow down and promoting a sense of calm and relaxation.
2. Lowered blood pressure: Diaphragmatic breathing can help reduce blood pressure by activating the parasympathetic nervous system, which counteracts the body's stress response.
3. Enhanced digestion: The vagus nerve influences digestion by increasing digestive enzyme production, improving nutrient absorption, and promoting smooth muscle contractions in the gastrointestinal tract.
4. Decreased stress and anxiety: Deep breathing has been shown to activate the relaxation response, reducing the release of stress hormones like cortisol and promoting a sense of well-being.
5. Improved emotional regulation: By stimulating the vagus nerve, diaphragmatic breathing may help regulate emotions and contribute to stress management.