Static apnoea, as practiced by Stephane Mifsud (Image: Philippe Joachim / UWPress.com)

Most people find it hard to hold their breath for more than a minute, so imagine the extreme self-control Stephane Mifsud mustered on 8 June last year when he held his breath for 11 minutes and 35 seconds, setting a new world record for stationary breath-holding, or “static apnoea”.

Competitors float face down in a chilled pool, not to stop them cheating but to induce the mammalian diving reflex: when your face is submerged in cold water, outer blood vessels constrict, directing blood away from the extremities and towards the heart and brain. Your heart rate slows, reducing the rate at which oxygen is pumped around the body. With training, experienced breath-holders can drop their heart rate by twice that of non-divers upon immersion in cold water.

Hyperventilation before a prolonged breath-hold is also vital. This is because the brain monitors the amount of carbon dioxide in the blood to decide when to trigger the gasp reflex. Purging this CO 2 with rapid deep breathing increases how long you can go before the urge to gasp becomes irresistible. Having large lungs is a natural advantage.

So have we reached the breath-holding limit yet? Not at all, says physiologist Johan Andersson at Lund University in Sweden, who studies the effects of breath-holding in divers. “Elite breath-hold divers expect the limit to be extended to about 15 minutes before record-setting will level off.”

They may be dicing with danger, though. Andersson found that static apnoea attempts on dry land caused a brief 37 per cent rise in the level of …