Dunking your face into a bowl of cold water while holding your breath triggers the mammalian dive reflex: this slows the heart, preserves oxygen for the brain, and causes the spleen to contract, thereby releasing red blood cells to provide an oxygen boost of approximately 10%.

noli's read

The mammalian dive reflex, activated by the contact of cold water on the face combined with apnea, is a robust and well-documented physiological phenomenon. Experimental studies, such as those by researcher Erika Schagatay published in the Journal of Applied Physiology, confirm that this process instantly slows the heart rate and redirects blood flow to vital organs. The role of the spleen as an emergency reservoir is also validated: it contracts to release oxygen-rich red blood cells into the circulation. As for the 10% oxygen boost, the work of Melissa Ilardo herself (published in the journal Cell, an observational and genetic study) demonstrates that while this capacity is maximal in populations of trained divers, it remains measurable (often between 3 and 9%) in untrained subjects. It is a simple, accessible, and scientifically validated method for stimulating vitality and calming the nervous system.

the sources

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