How Free Divers Hold Their Breath

How Free Divers Hold Their Breath

How Free Divers Hold Their Breath

How Free Divers Hold Their Breath


It sounds unbelievable to most people that a free diver can hold his breath underwater for more than five minutes, but the science behind this incredible feat is straightforward.

This is the reason why whales and dolphins swim for miles underwater and also explains the reason why when a six-month-old baby is placed under water his windpipe shuts automatically to prevent water from entering his lungs. The name for it is Mammalian Diving Reflex, MDR. All mammals including humans are born with it, and with training, it can be strengthened to make freediving possible for divers.

Another term for freediving is Apnea. It’s a Greek word meaning “without air.”

When our bodies are immersed at great lengths, MDR triggers our senses to conserve oxygen, optimize its use and protect our organs at these depths. A good example is when our faces come into contact with water, and the breath-hold is triggered automatically.


Slowing of the heart

If you’re not a free diver, the phrase ‘slowing of the heart’ may sound scary but is of great benefit to free divers. If your heart pumps fast, more oxygen is getting used, and this means that a slow pumping heart will correspondingly conserve more oxygen. For you a non-free diver, if you immerse your face in water briefly, your heart slows by an average 10 to 30 percent of its beating rate, and this is called bradycardia.

So free divers who train frequently can experience a 50 percent heart bradycardia rate. Also, the effects of bradycardia are also influenced by water temperature. The colder the water is, the higher its effects. This is the reason you can have a longer breath-hold time underwater than when in dry land. So, if you’re looking to hold your breath underwater for longer, you’ll need to learn about specific techniques that make it easy.

The first lesson is never to dive solo. Deaths in freediving from pros to novices are often caused when people dive beyond their skill level or ignoring necessary support. The techniques highlighted here offer an excellent opportunity for your journey to becoming a great free diver and will come in handy when underwater.


Holding the breath

Holding your breath underwater for the longest possible time without shifting is called “static apnea.” Dives can be performed using pure oxygen and without pure oxygen. Trainers allow divers to hyperventilate for up to 20 minutes with pure oxygen, enabling the body to expel carbon dioxide.

One theory suggests that the reason hyperventilation allows you to retain your breath longer is that your blood is becoming saturated with oxygen and that the more oxygen you maintain in your bloodstream, the longer you can hold your breath. Research also shows that divers who breathe in pure oxygen right before diving can indeed stay longer underwater.

But another theory suggests that hyperventilation tricks your body into imagining you could be having more oxygen than you do by reducing the carbon dioxide in your bloodstream.

When you inhale, the oxygen that comes in is quickly turned into carbon dioxide. When you hold your breath, the carbon dioxide starts to build up, and when the buildup becomes uncomfortable, you feel an overwhelming urge to inhale some oxygen into your system. But when you hyperventilate, the amount of carbon dioxide in your system is reduced, but the oxygen remains the same.