Extending the length of your exhalation is a fundamental element of yoga practice. Regulating the breath so that it is smooth and consistent has many benefits and is the primary way that you can manage the activity of your sympathetic nervous system – flight or fight response.
The most common method of regulating the breath is Ujjayi breathing – throat breathing. It is done by contracting the muscles of the vocal chords to slow the out breath. Begin by humming as you exhale and when you are used to controlling your exhalation that way do exactly the same thing but without the noise.
There will be a rasping sound as you exhale which you can focus on to improve your concentration and get feedback about how you are breathing. Be careful not to clench you teeth or have a stiff jaw. You can put the tip of your tongue behind your upper teeth or put it between your teeth to help you keep your jaw muscles relaxed.