Study shows free divers can drop heart rates as low as 11 beats per minute

Everything I know about free diving I learned from The Big Blue. I can hardly hold my breath for the length of a typical backyard swimming pool. I can hardly imagine diving to beyond 100m deep on a single breath for over four minutes.

So, yes, I'd put this up there as one of the most remarkable feats of human stamina, coaching one's body to rethink everything it believes about our most fundamental biological process – breathing.

Now there's a study from the University of St Andrews, Mid Sweden University, Carnegie Mellon University and the University of Tokyo, that has found just how far free divers push their oxygen management. Beyond even limits the researchers were expecting was possible before a blackout would occur.

The researchers were developing tracking technology that would help to alert free divers when they were in need of assistance, and so they had to learn the baselines these athletes operate at. The study delivered good results for the monitoring tech, but also revealed some amazing data on how different these people are to the rest of us.

“We measured heart rates as low as 11 beats per minute and blood oxygenation levels, which are normally 98 per cent oxygenated, drop to 25 per cent, which is far beyond the point at 50 per cent at which we expect people to lose consciousness and equivalent to some of the lowest values measured at the top of Mount Everest.”- Dr Chris McKnight, of the Sea Mammal Research Unit (SMRU) at the University of St Andrews

I love that Dr McKnight is indeed a 'sea mammal' researcher, and this process found that the free divers are operating in ways that surpass even some of our water-based mammal friends, including dolphins, seals and whales.

Off to watch The Big Blue over again.