Definition - What does Bahya mean?
Bahya is a Sanskrit term meaning "outside" or "external." Bahya pranayama is a breathing technique and one of the vital breathing exercises. During bahya pranayama the yogi deeply inhales, then completely exhales the breath and holds it. The breath stays out during the breath retention, which is why this technique is called bahya.
This breathing technique should be practiced in a sitting pose, and the breath should be held while touching the chin to the chest, pulling the belly in and lifting the groin muscles. These activities engage jalandhar bandha (throat lock), uddiyana bandha (abdominal lock) and mula bandha (root lock). With the inhale, the locks should be released again. It is recommended to practice this breathing technique for two to five minutes daily.
Yogapedia explains Bahya
Bahya pranayama has many benefits. It can ease constipation and hernias; positively affect individuals suffering from diabetes; cure prostate, sperm and urine ailments; support digestion; improve concentration; and calm the mind. It is contraindicated for yogis with heart conditions, blood pressure issues, or who are pregnant.
This breathing exercise should be practiced after kapalbhati, so the energy created by kapalbhati can evolve into greater forms. It should also be practiced on an empty stomach.
Engaging the three bandhas during the practice is called the tribandha, known for awakening the power of kundalini.