Almost anyone in decent physical condition can become a freediver. The key to not breathing underwater is breathing very well above it. In other words, a good diving experience begins with good preparation on the surface. A relaxed body and restful mind are essential prerequisites to any dive, and most athletes would probably agree that they are one and the same. Through specific breathing techniques, apneaists achieve control of the breath, which then leads to greater body awareness, muscle control and deeper states of relaxation. With experience, divers develop their own relaxation, visualization and breathe-up routines. This article is for academic interest only and does not include any specific techniques, since there is no substitute for proper training from a qualified instructor.
Pre-Dive Rituals
In order to be as efficient as possible, one needs to hold as much oxygen in his or her system while expending it as slowly as possible.The best possible results arise when thorough preparation on the surface combines with our body"s system of natural reflexes when we venture underwater. Aware that the mind could be relaxed through control of the breath, freediving legend Jaques Mayol introduced yoga and meditation to the sport, in particular ancient pranayama breathing techniques, which deal with “the art and science, not only of breath control, but also that of Vital Breath, of the vital energies of the cosmos”.
Performed with standard yoga postures (asanas), effective pranayama focuses on the awareness of breath and allows one to voluntarily influence processes like metabolism and heart-rate. This control is significant because slowing of the heart rate (bradycardia), reduced metabolism of oxygen, and blood shift (where blood leaves the body's extremities and concentrates in the torso and head to sustain the vital organs) are all part of an involuntary response set previously thought to occur only in whales and dolphins. In humans, the Mammalian Dive Reflex (MDR) is an instinctual adaptation to being underwater. It can be triggered by slowed breathing, facial immersion in water, and changes in pressure on the body brought on by variations in depth. Paying attention to controlled and methodical breathing on the surface helps prepare the freediver for these changes and also ensures that the blood is rich in oxygen by the time the athlete is ready to descend.
Don't Hyperventilate When Freediving
Contrary to popular belief, hyperventilation is not effective - it's dangerous. Under normal conditions the urge to breathe occurs when carbon dioxide (CO2) builds up in the body. When the CO2 needs to be expelled, we exhale. The body has two types of sensors: one registers when oxygen (O2) levels are too low; the other signals when CO2 is too high. The O2 sensors are actually quite poor, so the superior CO2 sensors basically run the breathing instinct. The problem with hyperventilation is that not only does it not effectively raise O2 levels, it also depletes CO2 levels. Imagine a tired diver, low on both gases. The C02 sensors do not detect any dangerous build up, so by the time the urge to breathe urge occurs, O2 levels are critical. Any subsequent panic or exertion to reach the surface puts the diver at risk of blackout and possible drowning. Oxygen-rich blood is not achieved through hyperventilation, but rather through a systematic routine that involves slowed deep breathing punctuated by regular flushing breaths to rid the body of excess gasses.
Specialized Freediving Techniques
Apneaists can also maximize their time underwater by inducing the MDR early in the session. Through performing a series of shallow Exhale Dives (see Introduction to Freediving Equipment and the Various Disciplines) the sudden and large changes in hydrostatic pressure on the body trigger the above processes. Regarding breathing, "packing" is the technique performed after a freediver has already taken a single full , last breath before descending. The diver then takes small gulps of air and literally packs that extra air in their lungs. It's highly effective but requires special training, including specific stretching exercises for the chest and ribcage to prevent internal damage through over-expanding the lungs.
All freedivers need to equalize or compensate for changes in pressre underwater. Since valuable oxygen is invariably lost through the need to equalize the mask, the sinuses and ears, it's necessary to be efficient when doing so. Of the two main techniques, the Valsalva is the easier. Pinching the nose closed and blocking the mouth, air is forced into the ears from the lungs (just as one might clear your ears during an airplane flight).) The Marcante-Odaglia or “Frenzel manoeuvre” is a hands free technique that involves isolating the nasal airways from the lungs using the tongue, jaw and musculature and then pumping air into the smaller nasal cavities. The latter is more energy efficient and results in less loss of O2. An ingenious but advanced method to conserve O2 is Wet Equalization (flooding the sinuses with sea water to create a balance between internal and external water pressure) but it's very difficult to master and can lead to infections.
Freedive Recovery
After returning to the surface, the recovery breath assists the apneaist to return to normal breathing and functioning. Since most blackouts occur at this stage, it should always be done in the watchful presence of another diver. Different forms of the recovery breath exist but the combination of a controlled inhalation followed by a relaxed flushing exhalation is thought to be best. After a few dives the MDR will have created a state that freedivers term “aquatic,” where being underwater becomes blissful, and returning to the surface begins to feel foreign. The recovery breath helps to bridge these two experiences and maintains calmness of body and mind which will allow the athlete to comfortably go into the next breathe-up for the next dive.
Proper control of the breath leads to oxygen rich blood, slowed heart rate and a greater sense of awareness. Jean-Marc Barr, actor in The Big Blue (based on Jaques Mayol), comments on the "divine peace one feels when alone, without air at 30 metres. You become nature." If the dream is to become one with the ocean, conscious breathing is the key.
Sources
- Umberto Pelizzari, Manual of Freediving, Idelson Gnocchi, 2004
- Jaques Mayol, Homo Delphinus - The Dolphin Within Man, Idelson Gnocchi, 2000
Grant van der Vijver - I love nature, people and the power of words. My range of interests includes science - particularly the mystery of water, nutrition, ...
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