This advanced PLB exercise will allow you to carefully set inhalation/exhalation ratio and define pauses at lowest and highest lung volume. Breathing with prolonged exhalations (as seen in image) has been effectively used to treat hypertension and elevated blood pressure resulting in lower blood pressure and lower consumption of drugs.

In humans inhalation is an active movement with the contraction of diaphragm and auxiliary muscles; it creates negative pressure and “sucks” air into the lungs. Exhalation is generally a passive movement as the air flows with the pressure gradient and thus no muscle work is essentially needed in its process. Because inhalation is an active and exhalation is a passive movement, breathing affects autonomous nervous system in such way that during inhalation there is an increase in sympathetic activity while during exhalation there is an increase in parasympathetic activity. As a result a heart rate increases during inhalation and decreases during exhalation, a phenomena observed as heart rate variability  and commonly explained as respiratory sinus arrhythmia Corresponding neurochemical mechanisms of this interaction are documented in research of vagal feedback, vagal modulation and external vagus nerve stimulation. Such a sequence of active inhalations and passive exhalations, usually referred to as negative pressure ventilation, is common to all vertebrates with the exception of amphibians and some reptile species who use additional pumping mechanisms to force oxygen into lungs.