Great athletes typically have slow heart rates from being in such good physical shape, but only one group has to rely on their hearts beating incredibly slowly in order to stay alive: free divers.
The extreme sport of free diving involves diving to depths of several hundred feet without the benefit of an oxygen tank. In 2021, a team of international researchers studied what happens to free divers' bodies, and the results are stunning. For one thing, they can slow down their heart rates to just 11 beats per minute in order to preserve oxygen in the bloodstream, putting them on a par with the world's greatest swimmers: seals, dolphins, and whales.
Free divers can also hold their breath for longer than four minutes and survive underwater with incredibly low oxygen levels. The research team, made up of scientists from the University of St Andrews, Carnegie Mellon University, and the University of Tokyo, is the first to examine what happens in a real situation rather than a lab simulation because they adapted a biomedical device that can work in the deep ocean, despite the extreme pressure.
Free diving facts:
- The human body can adjust and withstand incredible pressure underwater that would kill a person on the ground.
- Babies that haven't learned to walk are naturally better at free diving than most adults, according to research.
- Herbert Nitsch holds the record for deepest free dive, at 702 feet (214 m).