# One Second Without Air: how swallowing pauses breathing

A swallow pauses breathing for a moment. The body then resumes air through exhalation, after a sequence coordinated by the larynx, muscles and neural control.

## The figure

A study of 12 healthy young adults measured deglutition apnea at 0.75 ± 0.14 seconds across 72 swallows. A meta-analysis of 37 articles found the exhale–swallow–exhale pattern in 77.4% of thin-liquid swallows.

## Instrument

The calculator divides pause duration by the length of one breathing cycle, `60 ÷ breaths per minute`, then expresses the result as a percentage. At 0.75 seconds and 12 breaths per minute, the pause takes 15.0% of a 5.00-second cycle. The button simulates two routes: air towards the lungs and a bolus towards the oesophagus.

## Mechanism

Swallowing inhibits breathing, raises the larynx, closes the laryngeal entrance and propels the bolus towards the oesophagus. The epiglottis contributes to protection, while exhalation after the swallow helps clear residue from the pharynx. The mechanism is a coordinated sequence, with variation by volume, consistency, presentation and age.

## Safe observation

Sit comfortably, breathe normally and observe a small sip of water. Do not extend the pause or swallow large volumes. Stop if you develop persistent coughing, pain or a choking sensation.

## Sources

- [Selley, Ellis and Flack, 1999](https://pubmed.ncbi.nlm.nih.gov/10341108/), duration of deglutition apnea.
- [Molfenter and Steele, 2018](https://pmc.ncbi.nlm.nih.gov/articles/PMC6802879/), respiratory-phase meta-analysis.
- [Martin-Harris et al., 2003](https://journals.physiology.org/doi/10.1152/japplphysiol.00806.2002), pharyngeal and laryngeal dynamics.
- [Martin-Harris et al., 2006](https://jamanetwork.com/journals/jamaotolaryngology/fullarticle/649535), breathing and swallowing across adulthood.
- [Matsuo and Palmer, 2008](https://pmc.ncbi.nlm.nih.gov/articles/PMC2749282/), coordination of mastication, swallowing and breathing.