What is Freediving?
Freediving, also called breath-hold or apnea diving is, at its simplest, diving without the assistance of breathing apparatus. Competitive freediving comes basically in three flavours – Time, Distance and Depth with six primary disciplines within those categories for both pool and open water diving. See more about competitive freediving disciplines here.
Freediving is an exhilarating but potentially dangerous sport. Pressures on the body in deep water freediving can reach 16.5 kg/cm2 and divers can suffer loss of motor control or even black outs when they push their limits. For these reasons, freediving is very heavily regulated to ensure athletes’ safety in both training and competition.
How is it done?
Freediving requires extreme physical fitness, mental discipline and intensive training. Freedivers train to understand and control their body’s reflexes allowing world-class athletes to hold their breath for as long as nine minutes in freediving competitions. The mammalian dive reflex is a key factor in freediving . This reflex is found in all known mammals, and puts the body into an oxygen saving mode to maximise the time that can be spent underwater. Freedivers harness this reflex and use it to lower and control their heart rate which saves the body energy and oxygen. The extra air which is forced into their lungs by “packing” prior to submersion continues to oxygenate the blood and can extend the amount of time that they can safely go without breathing. Freedivers can also experience a “blood shift” during their dives, which is the process of blood vessels constricting in their limbs forcing blood into the body’s organs, and at the same time filling the lungs with plasma which prevents lung collapse at depth. A dive usually ends when the freediver experiences another reflex that we all experience every day: breathing. Because there is no respiration during the dive, carbon dioxide (CO2 ) builds in the bloodstream and muscles. This build up of CO2 trips an overwhelming reflexive response to breathe that presents itself in the freediver as a contraction, which many freedivers can control for a period of time, before surfacing. Contractions are very visible to the spectator, and look somewhat like a very big hiccup or small convulsion.
Are We Any Good At It?
Definitely yes! Kiwi freedivers are world class and are prominent competitors on the world stage. There are currently at least 12 competitive New Zealand freedivers, six of which are ranked amongst the top 20 in the world.