When you breathe in, blood cells receive oxygen and release carbon dioxide. Improper breathing can upset the oxygen and carbon dioxide exchange and contribute to anxiety, panic attacks, fatigue and other physical and emotional disturbances.
This method is based on an ancient yogic technique called pranayama, which helps practitioners gain control over their breathing.
When practiced regularly, it’s possible that this technique could help some people fall asleep in a shorter period of time.
And from the lungs outward, techniques like this can give your organs and tissues a much-needed oxygen boost.
4-7-8 Breathing can help
This breathing exercise, also called the relaxing breath, acts as a natural tranquilizer for the nervous system. When you first begin, perform the exercise seated with your back straight. Once you have had a chance to get familiar with the technique, you can perform it while lying in bed.
1. Place and keep the tip of your tongue against the ridge of tissue behind your upper front teeth for the duration of the exercise
2. Completely exhale through your mouth, making a "whoosh" sound.
3. Close your mouth and inhale quietly through your nose for a count of 4.
4. Hold your breath for a count of 7.
5. Exhale completely through your mouth, making a "whoosh" sound for a count of 8.
Repeat the process three more times for a total of four breath cycles.
You will find this practice will calm the mind and nervous system, improve lung capacity, decrease heart rate and release muscular tension.
Source: verywellmind.com