How is it possible for some humans to hold their breath for +6 minutes, when the average human can only hold it for app. 1 minute?


I was watching this documentary on free diving, and was wondering how it was possible for these guys to hold their breath for so long compared to every one else

In: 542

Your subjective experience of needing to breathe isn’t the same as your physical need for oxygen. You actually can hold your breathe much longer than you think you can without blacking out.

This is partly because (for most people but not all) your need to breathe is based on carbon dioxide building up in your body rather than lack of oxygen. If you take deep enough mouthfuls of air, and just force yourself to not breathe, you can physically tolerate some of that CO2 buildup for awhile. The O2 won’t drop to dangerous levels until a bit later.

Final point though, this is assuming you aren’t moving (and therefore not needing oxygen more). So the final thing is that they’re physically prepped for it. Good cardiovascular efficiency.

The first factor is the Mammalian Dive Reflex. When your nose and mouth are submerged your body automatically does some tricks to reduce your need for oxygen. Your heartbeat slows, certain nonessential organs slow way down, parts of your brain slow down, etc. With zero training or preparation, you can almost certainly hold your breath much longer under water than on land.

Then, they also do a lot of training and preparation. One thing they do is hyperventilating. This is *not* something you should do without training! They breathe rapidly for a short time to saturate their blood with as much oxygen as possible before diving. Some may even do this with a higher oxygen mixture from a cannister.

Finally, as others have pointed out, they train to be aware of their body and suppress the *feeling* of needing to breathe. That feeling doesn’t come from your body detecting a lack of oxygen, it comes from your body detecting a buildup of carbon dioxide. With the other tricks, they have more oxygen so they know they can stay down longer when if their body is telling them to breathe.

They train for it for years. The average human probably takes 6 times longer to stagger round a marathon than a pro athlete.