When the sudden burst of air is combined with the endorphins released during sex, the result is a heightened thrill.
The Dangerous Appeal of Choking|Gideon|June 14, 2009|DAILY BEAST
At Scoville temperatures like that, your brain gets totally awash in endorphins.
Little Brother|Cory Doctorow
endorphins
[ (en-dawr-finz) ]
Substances produced by the brain that have painkilling and tranquillizing effects on the body. Endorphins are thought to be similar to morphine and are usually released by the brain during times of extreme body stress. The release of endorphins may explain why trauma victims sometimes cannot feel the pain associated with their injuries.