Freediving is a safe and fun water sport if you follow the safety rules. A trained freediver is knowledgeable about the drawbacks and the methods of avoiding hyperventilation. However, if you break these rules, risks begin to emerge, as in every sport, and after a while you will go beyond the limits of safety and comfort.
One of these safety rules is - don't hyperventilate before holding your breath!
Without going into too much detail, what is hyperventilation?
Hyperventilation is breathing more than necessary. Usually, the rate and amount of your breathing is dependent on an existing metabolic activity. If you produce more CO2 depending on the activity - you will breathe deeper or faster.
For example, you produce less CO2 while you sleep and your breathing is calm and quiet. But contrary, if you're running, you create a lot more CO2, which significantly increases your breathing rate and quantity.
Our Freediving breathing routine: We take relaxation breaths, hold our breath, and then take recovery breaths.
Relaxation breathing pattern may differ among free divers. And some freedivers may deliberately or unconsciously hyperventilate instead of relaxation breathing.
Why would a person do this on purpose? An effort to accumulate more oxygen (O2)? Is useful? On the contrary, since the vast majority of the O2 in your body is already bound by hemoglobins, it will not be affected by such respiratory manipulations.
For this reason, people often try to hyperventilate to reduce CO2 in the blood and delay the urge to breathe.
What about unintentional hyperventilation? The free diver may be unconsciously hyperventilating for reasons such as incorrect breathing technique or longer than required relaxation breathing time, environmental conditions, and stress. Although these are not obvious, they may indeed manifest as mild forms of hyperventilation.
Hyperventilation can manifest itself with symptoms that we do not experience under normal conditions, such as drowsiness, dizziness, blackout, tinnitus, hearing loss, tingling in the lips and face area.
We cover this subject with much more detailed and technical information under the title of breathing in free diving trainings, but in a simpler way, why is hyperventilation not a good thing for Free Divers?
Excessive breathing (hyperventilation) is dangerous for free divers for the following reasons:
- By reducing the level of carbon dioxide in the blood, the diver delays the symptoms of the need for breathing(urge to breath) and therefore risks sudden blackout without warning.
- It constricts the arteries that supply blood to the brain, less blood-oxygen goes out, and in extreme cases can cause blackout even before the diver leaves the surface.
- It raises the heart rate, it is the most oxygen-consuming organ, thus increasing the rate at which turns that the body burns valuable oxygen.
- It can bring the body from relaxed (parasympathetic) to 'pushing, freeze, fight or flight' (sympathetic) mode.
- It causes oxygen to bind more strongly to hemoglobin (Bohr effect), reducing your body's ability to use oxygen when it most needs it.
In conclusion – hyperventilation should be strictly avoided by freedivers! It won't do you any good, but it puts you at unnecessary risk.