Alternate Nostril Timer

The Physiology of the Nasal Cycle

Throughout the day, your body naturally shifts dominance between the left and right nostrils—a phenomenon known as the ultradian nasal cycle. Every 90 to 120 minutes, erectile tissue in one nostril engorges with blood, restricting airflow, while the other opens.

Research suggests this nasal cycle is tightly coupled with brain hemisphere dominance and autonomic tone. The right nostril is generally associated with sympathetic activation (alertness, analytical thinking), while the left nostril is linked to parasympathetic activation (rest, creative thinking).

Why force the alteration?

By manually overriding this natural cycle and forcing equal airflow through both channels, Alternate Nostril Breathing (Nadi Shodhana) mechanically balances autonomic arousal. It prevents the nervous system from becoming too heavily skewed toward sympathetic fight-or-flight or lethargic parasympathetic states.

How to position your hand (Vishnu Mudra)

Tuck your index and middle fingers of your right hand into your palm. You will use your thumb to close your right nostril, and your ring/pinky fingers to close your left nostril.