A sport developed from fishermen diving
There is such a group of people who like special underwater sports: By balancing the water pressure and controlling their breathing, they can dive to a depth of tens of meters without the help of any breathing equipment (such as a scuba system), at most relying on artificial fins and masks. Of underwater viewing and exploration. Excellent freediving athletes can even dive to more than a hundred meters deep sea, this is free diving. The 5-meter deep water area of the training pool is far from satisfying them, because their usual training depth is far more than this.
Although free diving is an emerging sport, its origins can be traced back to the fishing methods of ancient coastal fishermen. In order to survive, these fishermen have to hold their breath and dive into the sea to catch snails and catch shrimps, or use homemade spears to fish. Some countries still retain the ancient traditional customs of submerging and fishing for seafood, such as Japan, South Korea and some tropical island countries. Today, people systemize and professionalize free diving, and this sport is gradually taking shape.
Free diving is developed from the custom of diving and fishing by fishermen in some coastal areas
Human ancestors may have lived in the sea
The hydrophilic nature of humans may be related to our evolutionary process. In the process of evolution from ancient apes to Australopithecus (human ancestors), there is a gap of 4 million years of fossil evidence—scientists have not yet found fossils of transitional species during this period.
In order to explain the whereabouts of human ancestors during these 4 million years, British anthropologist Hardy put forward the "Sea Ape Hypothesis" in 1960. he thinks. The human ancestors in the fossil blank period did not live entirely on land, but lived in the ocean most of the time. Human ancestors may have had millions of years of aquatic life experience.
The "Sea Ape Hypothesis" can explain the above-mentioned fossil gaps. Geological survey results show that during this period of 8 million to 4 million years ago, large areas of eastern and northern Africa were submerged by sea water. Hardy guessed that with the gradual disappearance of the forest, the ancient apes are likely to be forced to go to the sea in search of food, and evolved into sea apes in the long-term aquatic environment. When the sea receded, they began to return to land, and retained some of the physical changes adapted to life in the water.
Chimpanzees and gorillas occasionally venture into shallow waters. They will walk on their two hind limbs when wading, and try to keep their heads out of the water as much as possible. If the ancient apes need to move in shallow water for a long time, then they should also walk upright. This habit created conditions for walking upright and freeing hands after returning to land, and perhaps allowed them to surpass other apes and eventually evolve into today's Homo sapiens.
Human aquatic characteristics
Some of the physiological characteristics of humans are different from other terrestrial animals, but they are similar to aquatic mammals such as seals and dolphins. This is the basis of the "sea ape hypothesis". The following human characteristics can support the "sea ape hypothesis".
Smooth skin
Terrestrial primates, such as apes, usually have dense body hair. Among all primates, only humans have the same smooth skin as aquatic mammals. This is also similar to animals with aquatic ancestors such as rhinos and elephants.
subcutaneous fat
The monkey’s face looks wrinkled because many parts of the body of terrestrial primates lack subcutaneous fat. Humans have perfect subcutaneous fat, which is exactly the characteristic of aquatic animals.
Salt regulation
Terrestrial animals have extremely fine salt intake and regulation functions: they are very sensitive to the salt in the body, and become anxious if the salt is insufficient. Humans and marine organisms are similar in that they lack fine salt regulation mechanisms. For example, humans rely on sweating to regulate their body temperature, which is obviously a waste of salt. And only in an environment with sufficient salt content (such as the marine environment), animals do not need to fine-tune the salt in their bodies.
Diving reflex
When the body of an animal with diving reflex is immersed in water, oxygen in the body will be preferentially transferred to important organs such as the heart and brain, and the heart rate will drop to extend the diving time, which is called diving reflex. Aquatic mammals such as seals, otters, dolphins, and muskrats have obvious diving reflexes. The diving reflexes possessed by humans are slightly weaker, but they can be strengthened through system training. Diving reflection is the most obvious aquatic feature of the human body, and it is also the feature that has the greatest impact on free diving.
Although the "sea ape hypothesis" lacks definite evidence, these biological characteristics of human beings still firmly point to the undeniable connection between humans and the ocean.
The difference between scuba diving and free diving equipment.
Avoid hyperbreathing
Hyperbreathing is also called hyperbreathing or hyperventilation, that is, continuous deep breathing, which exceeds the actual needs of the body. Free diving should try to avoid hyperbreathing, because hyperventilation will cause the concentration of carbon dioxide in the blood to drop and delay the time when the desire to breathe appears. Severe hyperbreathing can even cause people to have no desire to breathe before fainting. This will make us unable to control our underwater stay time, so it is very dangerous. However, as long as we do a good job of adjusting our breath before entering the water, we can avoid this dangerous super-breathing.
Turn on "mermaid mode"
If human beings want to re-open the "mermaid mode", they must first overcome the fear of water. Most of us have learned from our parents the notion that it is dangerous to enter the water since we were young. When we first came into contact with water, we were often inadequately prepared and even forced to fall into the water, which created an inexplicable fear of water. Even if many people learn to swim later, it is difficult to completely get rid of this fear.
The so-called water is the ability to adapt to aquatic life, which includes both physiological and psychological adaptation. In free diving, we mainly need to do three things: first, adjust and improve breathing, relax the spirit, let the body use oxygen efficiently, and quickly resume breathing after exiting the water; second, adhere to free diving exercises to improve "diving reflexes" "Response speed and intensity; Finally, recognize the desire to breathe, determine the timing of water, enhance the body's tolerance to carbon dioxide, and enhance the comfort in the water. (Please refer to the related link: "Three Steps to Learn Freediving")
Free diving is different from track and field sports. The former does not pay attention to the display of explosive power, but pays more attention to mental performance. For example, if you want to improve your breath-holding level, you need to remain mentally calm.
Free divers have close contact with fish
Learn to freediving in three steps
The first step is to control the breathing rhythm
Freedivers complete a dive with just one breath. In order to increase the single underwater residence time and save physical energy, it is necessary to improve the oxygen utilization efficiency in this "single breath". We can reduce the body's oxygen consumption level by relaxing and adjusting the breath before entering the water, and try to continue this state of physical and mental relaxation after entering the water.
Breath adjustment freedivers adjust the chest breathing to abdominal breathing before entering the water, while avoiding "super breathing" (see below for details) to improve the efficiency of oxygen utilization. Abdominal breathing refers to inhaling and exhaling through the expansion and contraction of the abdominal diaphragm, that is, the abdomen needs to be expanded when inhaling.
Holographic Before entering the water after pranayama, we also need to do a holographic (also called full breath) to fill the lungs with fresh air to the maximum. Full breathing requires a combination of abdominal breathing and chest breathing, that is, when inhaling, first expand the abdomen to the greatest extent, and then expand the chest cavity to the greatest extent, so as to ensure that the lungs are full of air.
After we stop and enter the water, we will be in a stopped state, that is, we will stop breathing. At this time, the diver should relax the whole body, let out his thoughts, and stop distracting thoughts, which will help save oxygen to the maximum.
After the compound breath completes a dive, the first priority after exiting the water is to restore the oxygen content in the body through rapid breathing. When the hypoxic condition was relieved, we switched to the pranayama phase again to prepare for the next dive. The breathing control of freediving is the cyclical process of the four breathing rhythms of "breath adjustment-hologram-stop-replenishment". When we can make reasonable use of this new breathing rhythm, we can swim in the sea.
The second step is to strengthen the diving reflex
There are two main ways to trigger the diving reflex mechanism. One is to immerse the face in cold water (other parts of the body contact with cold water will not trigger this mechanism). The second is to hold your breath and hold your breath so that there is too much carbon dioxide and too little oxygen in the blood. This reflex can be triggered even when we practice apnea on land. During free diving, due to the stimulation of cold water and the process of holding your breath, the diving reflex will be more easily triggered.
The third step is to identify the desire to breathe
When doing free diving, how do we judge when we should end the dive and return to the surface to breathe?
When you hold your breath until the abdomen begins to twitch or contract, the body will produce an emotional response to breathe, and the diaphragm will twitch, which is the desire to breathe. Beginners generally think that the desire to breathe indicates insufficient oxygen in the body, but this is not the case. Scientists have discovered through research that the generation and enhancement of the desire to breathe is actually determined by the concentration of carbon dioxide, and has nothing to do with the amount of oxygen in the body. Therefore, in the initial stage of the desire to breathe, the body does not really enter a hypoxic state.
Based on this principle, advanced freedivers can increase their tolerance to carbon dioxide, thereby extending the diving time. The underwater apnea time of well-trained freedivers can usually reach more than 4 minutes.
However, although the significant increase in carbon dioxide tolerance can extend the time of holding breath, it also brings certain risks. This is the occurrence of fainting and loss of control in the state of extreme hypoxia.
Fainting refers to the sudden loss of consciousness in the brain and a person enters a coma. If the fainting occurs after a deep dive and rises to a few meters in shallow water, we call it "shallow water fainting."
Loss of control means loss of autonomic function control. Its main symptoms include body and head tremor, movement disorders, narrowing of the field of view, and purple lips. The severity of the disorder varies according to the degree of hypoxia.
The difference between free diving and scuba diving
During my study of freediving in Koh Tao, Thailand, every time I went to the diving site "Yuyue" after the sea training, I always met many scuba divers who were sightseeing under the sea. The difference between free diving and scuba diving is like the difference between a dolphin and a submarine. Dolphins are highly mobile but have a short underwater residence time; submarines are weak but have a long underwater residence time. Whenever the diving companions (like dolphins) pass by the "submarine" wearing the gas tank, there will be a sense of freedom of "fish joy"-we don't need a breathing mouth!
Although both are called diving, free diving and scuba diving are two completely different sports. This difference is so big that even "air" cannot be shared. The ascent speed of freedivers is very fast when they come out of the water, which is used by scuba
The International Free Diving Association has developed scientific sports regulations to ensure the safety of divers. For example: gradually improve your abilities, don’t set goals that are far beyond your current abilities, don’t dive alone, have buddies to take care of each other and provide rescue, etc. Therefore, although free diving is considered to be the second most dangerous extreme sport in the world, as long as the scientific sports norms are followed, the danger is not great.
Compressed air increases the risk of decompression sickness. At the same time, if you do not breathe out in time, the expansion of compressed air will cause severe lung barotrauma. Therefore, freedivers are strictly prohibited from using compressed air.
What is decompression sickness? During the ascent process, if the speed is too fast, the nitrogen molecules accumulated in the blood will not have time to enter the pulmonary circulation, and tiny bubbles will form and stay in the blood, affecting blood circulation. Therefore, scuba divers must strictly control the ascent speed. And freedivers usually don't have to worry about decompression sickness, because freedivers only use one breath to get up and down, and they don't accumulate much nitrogen in the blood. If scuba divers want to perform free diving, they must be at least 18 hours apart between these two exercises to ensure that the dissolved nitrogen in the blood is fully discharged from the body.
