Breath-holding to the limits of human capabilities. How breath can help our body make better use of oxygen
Can you recall your childhood, watching the movie Cosy Dens or simply diving underwater and for a moment feeling like at least Ariel, the little mermaid? Today we won't be talking about how long we can stand to look at the carp that has been swimming half out of breath in our bathtub over the holidays, nor will we be racing with Pepík next door in holding our breath "until the count of ten". We're going to go much further. In fact, we're going to go beyond our limits. We'll learn not to breathe and still take in the beauty that will surely take our breath away.
Holding your breath can help with your overall fitness. Learning to hold your breath properly takes practice, but it is also a powerful tool to improve your overall physical shape and health. In fact, breath-holding teaches our bodies to use oxygen better, which is very useful in these COVID times. Proper breath-holding is, among others, a forte of freedivers. Training in conditions of moderate oxygen deficiency improves our body's resistance to many pathogens, and hypoxic training boosts the development of its compensatory reserves. So when’s a better time to take the plunge than now?
The one-breath dive
Freediving or apnea diving is a sporting discipline where a trained person dives without a scuba set, only using the air supply in their lungs created by taking a breath while above the water surface.
This type of apnea is then divided into static and dynamic apnea (in which, however, the oxygen in the lungs is used up much more quickly than in static apnea). Nevertheless, both disciplines are equally demanding. In short, you must learn not to breathe and then hold your breath as long as possible underwater. And although it can certainly be trained, you need an expert to guide you through the whole process SAFELY. If you start training yourself, you might be in for trouble.
"Underwater breath-holding must be done in the presence of a coach who will identify a problem (recognize if e.g. the athlete is not responding to instructions or exhales into the water) and intervene in time,"
Gabriela Grézlová told LP-Life.com.
A little history
Freediving (Apnea diving) is historically the oldest way of fulfilling the human ambition to venture under the water surface. Archaeological findings of pearls or shells that could not be fished out with a net, but only collected on the seabed by a human hand, date back to as early as 4,500 years ago. Obviously, the idea of people of that time having gills or perfect technology is only possible in legends or myths.
They had no other option besides holding their breath. From the time of ancient Greece, we know apnea diving for sea sponges, valued greatly from ancient times until their recent replacement by porous synthetic materials. But the Greeks were not the only ones who intensively ventured underwater in historical times. In his travel notes, Marco Polo described divers capable of diving to depths of more than 20 meters in a single breath.
Famous are the diving activities of the pearl collectors of the Tuamotu archipelago or the diving women called Ama – Korean and Japanese gatherers of pearls, crabs and edible seashells who have been diving this way for 2 000 years, up until recently.
Because of its minimal economic cost, apnea diving has become a widespread recreational leisure activity. However, it shouldn’t really be called recreational, as you actually need to train hard in order to get at it.
"First of all, you need to train stretching the diaphragm and chest, with the aim of increasing the vital capacity of your lungs,"
Eventually, in the 1950s and later, the first experiments with apnea diving to greater depths began to appear (Raimondo Bucher 30 m/1940, Enzo Maiorca 50 m/1962, Jacques Mayol 100 m/1976). Finally, apnea diving became an accepted sport discipline with an international organization. And the Czechs are damn good at it!
Loss of consciousness as a possible threat
Intentionally increasing the frequency and depth of breaths before a dive can cause a scuba diver to lose consciousness underwater and subsequently drown.
Clinically speaking, this loss of consciousness is called posthyperventilation hypoxic syncope. Spontaneous physiological respiration in humans is mostly regulated by the rhythmic excitability of our respiratory centre, located in the reticular formation of the caudal medulla oblongata. This respiratory control centre is stimulated by changes in arterial blood chemistry, where a rise in pCO2 increases the level of respiratory centre activity. In addition to the medulla oblongata, other sensors (chemoreceptors) informing the respiratory centre of the current blood chemistry are located in the carotid and aortic bodies.
"Human breathing is pre-set by itself in a certain way and any interference from outside can therefore cause disturbances in the body,"
Mudr. Anna Velísková tells LP-Life.com.
When a diver holds their breath after a period of hyperventilation while moving underwater in apnoea, the metabolic demands of the body cause a further decrease in pO2 and a simultaneous increase in pCO2 in the blood. The proportion of pCO2 in the blood is significantly lower in this situation compared to the same situation without prior hyperventilation. Thus, a paradoxical situation may arise when the pCO2 in arterial blood reaches a concentration sufficient to stimulate the respiratory centre only at a time when the whole organism and especially the central nervous system of the diver's CNS is already in a state of advanced oxygen deprivation (hypoxia), which is usually manifested by a sudden loss of consciousness.
The so-called called 'taravana syndrome' is characterized by the appearance of decompression sickness symptoms, but in a diver in apnoea.
The history of the description and scientific explanation of this phenomenon has its roots in the Polynesian archipelago of Tuamotu. Here, for generations, pearl hunting has taken place. After taking a deep breath, native divers descended to the bottom using a weight tied on a rope together with an oyster basket. The working depth of the dive was 10-40 meters with a single dive lasting 30-60 seconds and a breathing interval between two dives at the surface of 3-10 minutes. The daily working time, consisting of repeated dives, was about six hours. At the end of such a working day, up to 20% of these indigenous apnoea divers developed vertigo, nausea or anxiety. Vision disturbances, hearing loss, and sometimes even paralysis of the limbs with loss of consciousness and death within two hours of the end of the dive occurred as well.
During repeated dives to greater depths, the diver's chest and lungs get compressed externally by the hydrostatic pressure of the water and the volume of alveolar air is compressed in the same way, with a corresponding increase in the partial pressures of the individual gases. The partial pressure of nitrogen in the alveolar air increases briefly during descent and residence at depth, with small amounts of this inert gas dissolving in the blood by pulmonary microcirculation. When this process of increasing pN2 in the alveolar air is repeated periodically and frequently, under these circumstances a gradual microsaturation of the blood with nitrogen occurs, eventually sufficient to allow that gas, given an adequate pressure gradient, to penetrate into the tissues (initially those with a richer microcirculation).
Subsequently, when diving to greater depths for several hours, nitrogen may accumulate in the diver's body to such an extent that in a course of repeated surfacings, microbubbles of this gas may begin to form in the body. Under these circumstances, in such a hyperbarically exposed individual, suitable biophysical conditions for the manifestation of various decompression sickness symptoms – including the most severe ones such as paralysis or death – are created.
Into the depths in a single breath
Freediving is an extreme sport that continually pushes the limits of human capabilities and reveals our ability to adapt to the environment below the surface and become part of the marine environment for a while, observing all the beauty around us.
As the Irish scientist Robert Boyle studied the effects of water pressure on the human body in the 17th century, he concluded that about 30 meters below the surface would liquid simply tear our lungs apart. His thesis became known as Boyle's Law and was considered valid for many centuries. But in 1949, Hungarian pilot Raimondo Bucher took a bet and dived to a depth of 30 meters. Not only did he win 17,000 crowns in today's money, but he also laid the foundations for so-called freediving, i.e. apnea diving. In the following years, one record after another was broken in the discipline: for example, in 1976, Frenchman Jacques Mayol sank to 100 m, which, however, is the standard depth for a freediver engaged in the sport nowadays.
The extreme full of extremes
The underwater breath-holding primacy is now held by Aleix Segura from Spain, who lasted for 24 minutes and three seconds. The record for the deepest dive belongs to Herbert Nitsch from Austria, who reached 214m. Even though he also went down to a hardly believable 252m, this feat is not valid, because the diver lost consciousness on the way back. Mateusz Malina from Poland is the first in terms of distance swum, covering 244m without fins and 300m wearing fins in one breath underwater.
It's true that with the right guidance and enough training, any person in decent shape can become a freediver: 20m of depth and two minutes without breathing are really no problem. It is also true that freediving is primarily a recreational sport. But how is it possible for a land creature to achieve these extreme feats underwater? Initial studies suggested that, purely on the basis of lung volume and the shape of the human body, such records should not be achievable. In the end, however, it turned out that we are much better suited to being underwater than we thought.
"There really is something to be learned. The human mind is limitless in this regard; it's just a matter of how you set it up,"
Greg Walmont, a yoga instructor who specializes in breathwork, told LP-Life.com.
For example, it has been found that when diving, the human heart rate drops drastically, similar to aquatic animals. Per Scholander, a physiologist from the Scripps Institution of Oceanography in the USA talks about a "diving reflex". And this very adaptation helps us understand the divers‘ incredible feats. Underwater, our bodies enter a state similar to hibernation, with the heart slowing down to 40 beats per minute, or, in exceptional individuals, even as low as ten. It also reduces oxygen consumption. Moreover, blood from the limbs is transferred to the heart, brain and other vital organs: the lungs are the main beneficiaries of this principle, as they draw it in and form an imaginary protective wall. Therefore, they do not burst in the depths as Boyle thought, but merely contract.
Mental training is important as well, as freediving can be an extreme sport, but certainly not an adventure one. Excitement is not conducive to performance; on the contrary, maximum calm and relaxation are required, which again reduces oxygen consumption. Many freedivers approach diving as a meditation: they try to empty their mind as much as possible, which positively affects the time they are able to spend underwater. Surprisingly, the diving reflex can even be seen in children. And tribes for whom underwater hunting has become a daily routine show other physical modifications as well, such as a more economical metabolism or a slightly different eye structure (see Underwater nomads).
"Meditation can be done anywhere; it's mind work where we try to completely stop the flow of all our thoughts. Therefore, it doesn't matter whether you are sitting on a mat, running or happen to be underwater,"
Obviously, freediving holds some risks as well, especially in its extreme sport varieties. Still, as long as you take precautions and don't dive "all the way in", it's a relatively safe activity in general. The biggest killer is the so-called blackout or sudden loss of consciousness. Simply put, it occurs due to lack of oxygen, but it is also the result of over-breathing before the dive, pressure changes during ascent, etc. However, it is relatively rare and the greatest danger lies in the fact that it is usually not recognized in advance.
The only hope for an unconscious diver is, of course, to be pulled to the surface. As in the case of conventional diving, it is therefore advisable to go down in pairs. Another safety feature is proper balance - up to their limiting depth, the freediver should have a light buoyancy. Thus, if they were to lose consciousness, for example, their body would start to rise up on its own.
World breath control champions
When holding breath, Aleix Segura thinks of his heart. On land, concentration causes his heart rate to increase - but underwater it has the opposite effect.
"Once my muscles are relaxed and my heart has slowed down, I kind of... disconnect,"
says this world champion of his breathing. Sometimes he gets so relaxed that he falls asleep.
Fifty-six-year-old Croatian diver Budimir Buda Šobat broke his own world record by holding his breath underwater for 24 minutes and 33 seconds. He beat his own best by about two minutes. This Croatian performed his breathtaking feat in a swimming pool in Sisak, southeast of Zagreb. The entire attempt was supervised by medical staff, as well as reporters and fans. Before Šobat dove into the water, he was given a supply of oxygen to get his body ready for the performance. After that, he lied face down on the water surface and the stopwatch went off. In his record attempt, he had to make the most of his training, even overcoming the cramps that came after about 18 minutes underwater. But as the diver himself says, cramps actually help him stay conscious underwater.
In the end, the Croatian diver kept his face underwater for 24 minutes and 33 seconds, beating his own record by more than two minutes. Compared to the record without inhaling oxygen before the feat, held by another diver, his time is almost double. After this successful attempt Šobat said that his biggest motivation is his 22-year-old daughter Saša, who has had polio, is autistic and went through several epileptic seizures.
When holding our breath and immersing our face in colder water, the so-called mammalian diving reflex kicks in in the first place; the brain knows it is not breathing, and to protect itself from damage, it slows down the heart rate. The blood flows more slowly and blood vessels in peripheral body parts and limbs constrict, so more blood circulates between the lungs, heart and brain. Pumping all the blood in the bloodstream takes the heart about a minute, and the tissues are far from consuming all the oxygen the blood carries in one "cycle."
Breath-holding is probably not exactly a "piece of cake", but it should be remembered that the mind plays a major role in this case. If you become the master of your thinking, you may be able to do more than you ever imagined.
Sources: apneaman.cz, padi.com, quora.com, dinetures.com, menshealth.com, coach.nine.com.au, freedivingfreedom.com, freediveuk.com, own inquiry