Welcome to brain stuff from how stuff works. Hey, brain stuff, Lauren Vogeldam, here you like most humans can probably hold your breath for about two minutes, though in twenty sixteen, Guinness World Records clocked free diver a leash Sigura Ventril of Barcelona, Spain, holding his breath for a little over twenty four minutes, which is of course completely wild. Humans aren't built for breath holding. We've got other priorities like
world domination. If we had spent even a little more of our evolutionary history working on holding in air instead of making our brains giant and complex, we probably could survive without oxygen at least as long as the average beaver, which is fifteen minutes. But there are lots of air breathing animals that are built for breath holding. A sloth can hold its breath for a whopping forty minutes because it's able to decrease its heart rate to about a
third of the normal. A sleeping sea turtle can hold its breath for up to seven hours at a time. A loggerhead turtles often forage under water for around forty minutes in one go, but one study of loggerhead activity found that males can voluntarily sustain themselves on one breath or sometimes a quick charge up of several successive breaths, for around ten hours. One female was observed going as
long as twenty hours. Some turtles can spend all winter long at the bottom of a frozen lake in deep hibernation, not using their lungs at all. The turtle secret is that during this period of almost complete system shutdown, it does take in a tiny bit of oxygen by breathing
through its highly vascularized cloaca. The cloaca being a single organ found in reptiles, birds, amphibians, and even some mammals that serves as the animals exit for its urinary tract and digestive tract, and that's also the opening for their reproductive tract. Yes, they pee, poop, and have sex with this single organ in turtles with cloacal respiration, they can also draw water up into their cloaca and absorb oxygen from it, then flush it back out. Turtle, however, are
ectotherms animals that rely on outside sources for heat. It's much easier for ectotherms to go without oxygen than endotherms like us mammals. We use a lot of oxygen keeping our systems running hot, which is why marine mammals like whales, seals, and otters are so impressive. They can pull off unbelievably long deep dives in order to hunt for food. Take Couvies beaked whale the deepest diving of all marine mammals, and the one scientists think holds the record for the
endotherm that's achieved the longest breath holding session. These midsized whales can dive around ten thousand feet that's about three thousand meters, hunting four squid and other deep sea goodies, and they can hold their breath for an average of sixty seven minutes, with one record dive that lasted a hundred and thirty eight minutes before a Couvies beaked whale broke the previous record. A northern elephant seal was the gold medalist, caught holding its breath at a hundred and
nineteen minutes. A sperm whale now comes in third place at ninety minutes. Not a long time to go without oxygen when you've got an expansive mammalian metabolism to keep up, but lots of marine and aquatic mammals make it work by slowing their heart rates and redirecting blood away from their extremities into their brains, hearts, and muscles. They even have special oxygen binding proteins in their muscles that allow
them to store more oxygen than us land lovers. Today's episode was written by Jessoline Shields and produced by Tyler Clang for iHeart Media and How Stuff Works. For more on this and lots of other multipurpose topics, visit our home planet, how stuff Works dot com