Hey, divers, don’t hold your breath too long

This article was originally on a blog post platform and may be missing photos, graphics or links. See About archive blog posts.

Breath-hold diving is a new sport that is becoming more popular. Divers compete for maximum under-water time, distance and depth. The best of these divers can hold their breath for 10 minutes in a state that is called static apnea. If that sounds dangerous, it is.

Although divers are rescued if they get in trouble during competitions, a new study suggests that the sport causes changes in the central nervous system that could damage the brain. Researchers in Sweden studied nine breath-hold divers (on dry land) and six people who had limited experience in breath-hold diving. The participants were instructed to hold their breath as long as possible while researchers took blood tests before, during and after the breath hold. They found a marker for brain damage -- a protein calledS100B -- rose in seven of the nine divers but in none of the control participants. The levels of S100B returned to normal in two hours in all the participants.

‘The results indicate that prolonged, voluntary apnea affects the integrity of the central nervous system and may have cumulative effects,’ the authors wrote. ‘A long-term follow-up study on individuals at the beginning of their careers as competitive breath-hold divers and after some years of apnea diving would be of great interest to clarify these issues.’

The study is published in the Journal of Applied Physiology.

-- Shari Roan