In Practicing the Tri Bandha we engage with Haṭha teachings:
In that, the inhale takes the Agni towards the Mūlādhāra.
This effect on Agni increases with the Antar Kumbhaka,
as the Antar Kumbhaka helps to intensify the fire.
Following this process in bringing the Agni down,
the exhale takes the Mūlādhāra towards the Agni.
Thus the exhale draws the Apāna towards the Agni,
plus adding Uḍḍīyana Bandha holds the Apāna up.
This is the link with the effect on the Kuṇḍalinī,
though in terms of practice, very hard to get.
Here also, the coming down period is important.
For example, do not eat just after, though you feel hungry.
Uḍḍīyana Bandha is a heating process and Madhura Rasa,
such as sweet rice cooked with milk is initially recommended.
Link to Series: 108 Mudrā Practice Pointers
Āsana and Mudrā Glossary
– Grouped into Standing, Kneeling,
Lying, Inverted, Backbend, Seated & Sitting
Glossary of Prāṇāyāma & Bandha Practice Techniques
– Grouped into Primary, Secondary & Ancillary Techniques