Summary
During normal breathing, there is a brief moment of breath retention in between the inhalation and exhalation, as well as in between the exhalation and inhalation. It is only for a split second and it is neither conscious nor controlled. Through this practice, we will become familiar with that brief pause that follows the exhalation and extend it.

The main benefit of exhale retention is that it trains the nervous system to tolerate higher levels of carbon dioxide in the body before it signals the brain to force the body to inhale oxygen. This trains us to control parts of the brain that are usually responsible for involuntary processes, as well as teaches us to consciously remain relaxed in uncomfortable situations.

Instructions
Sit in a comfortable relaxed position.

Allow yourself to relax while remaining erect.

Become aware of your breath as it flows in and out of your nostrils.

Begin counting to 4 on inhalation and exhalation.

Once your breath is smooth and even, begin exhalation retention.

Inhale for a count of 4, exhale for a count of 4, and keep your breath held out for a count of 2 before inhaling again.

If you feel any strain go back to normal breathing.

As you become comfortable with this practice, extend the count of exhale retention to 3, and then 4.

Practice 5 rounds.