Dive freely to the depths of the sea, dive!

  Free diving
  - a dangerous sport
  we all know, the world’s most dangerous sport is low-altitude parachuting. Compared to skydiving that takes off on an airplane, people call skydiving that takes off on low fixed objects such as tall buildings, cliffs, towers, and bridges as low-altitude skydiving. Due to altitude restrictions, the time for low-altitude skydiving to open the umbrella bag is often only 5 seconds, which makes it difficult for pilots to adjust their posture and movements in the air. Because the dangerous moment comes too fast, the fatality rate is extremely high, and parachuting at low altitude is daunting.
  But do you know what is the second most dangerous sport in the world? The answer is free diving. Free diving refers to a breath-holding exercise in which you do not carry an oxygen cylinder and only swim in deep water by adjusting your abdominal breathing. In fact, freediving is much more difficult to get started than low-altitude skydiving, and its difficulty is beyond ordinary people’s imagination. Low altitude skydiving means you need to take a leap, success or failure in an instant. To complete free diving, you must not only have excellent physical conditions, but also have strong mental qualities.
  The first difficulty of free diving is the buoyancy and pressure of the sea. Generally speaking, the density of seawater varies greatly. Like the Dead Sea, the density is too high to sink. As far as ordinary sea water and fresh water are concerned, the density of the human body is higher than them. But divers inhale a lot of air before diving, which will cause their density to be similar to that of sea water, or even less than that of sea water. Overcoming the buoyancy of the sea water to swim to the depths of the seabed, this is a very difficult task. Buoyancy only challenges people’s physical strength, and the pressure of sea water is even more deadly. We know that the deeper the sea, the greater the pressure of the sea. Although it becomes easier to dive in deep water, this is because the lungs are squeezed (which will happen gradually when the depth of the dive exceeds 30 meters), which makes the density of people increase, and they can sink without moving. The extremely high pressure in deep water forces blood into the weak air sacs of the lungs and destroys the lungs, which is fatal to humans. When the lungs are squeezed, people will feel pain, and the brain will always send out warning signals. Without a strong will, it is impossible to continue downstream.
  The second difficulty of free diving is “shallow water fainting”. Shallow water fainting refers to the phenomenon that a diver loses consciousness while surfacing and approaching the surface after finishing a diving mission. When diving, the diver’s capillaries tighten, thereby blocking blood flow, leaving oxygen and blood in the heart and brain. When approaching the water surface, the capillaries expand again, and blood begins to flow from the brain to the limbs. In this process, divers are prone to fainting due to lack of oxygen in the brain. If the diver is diving alone, fainting in shallow water means death. Under normal circumstances, shallow water fainting is only a temporary loss of consciousness and will not have a lasting negative impact on the health of divers. But if it happens too frequently, it will become a habitual reaction and become a safety hazard for the diver’s entire diving life.
  The third difficulty of free diving is hypoxia. The more able to withstand the hypoxic environment, the deeper the swim and the better results. However, if you blindly endure the hypoxic environment, people will faint. According to data, a person’s brain is deprived of oxygen for more than 6 minutes to cause irreversible damage. Of course, the specific situation will vary from person to person.
  He broke the world record again in
  274 seconds, about 4.5 minutes. What can you do? Make a cup of tea or take a cold bath? Someone used it to break the world record. You may dismiss it, 274 seconds is not a long time. But what if this is the time to take a breath? This is not easy. Of course, there are many people who can hold their breath for more than four minutes, but what about holding their breath for 274 seconds and free diving to 124 meters below the sea? You may drop your chin-124 meters is about the length of 2.5 Olympic swimming pools and 30 meters higher than the highest point of the Statue of Liberty, which is a world record!
  It was a sunny day on May 2, 2016, and the sea was sparkling. The annual free diving activity named “Vertical Blue Water” was held as scheduled, and the location was located in the Dean Blue Hole, the second deepest blue hole in the world by the sea in Clarence Town, Bahamas, Central America. Blue hole, which means blue water hole, is named after it automatically emits blue light. The focus of this event-36-year-old New Zealand diving master William Trubridge is warming up. Trubridge has been in poor condition in recent years and has never broken the world record he set before. Of course, no one can break the world record he set-for this free diving genius, perhaps his record can only be broken by himself. The good news happened two days ago, Trubridge successfully dived 122 meters underwater, pushing the world record he set in 2011 to the bottom of the sea by 1 meter. Now, he has to accept a new challenge.
  With the shooting of various cameras and the cheers of other contestants and spectators, Trubridge went into the water. He did not carry any propulsion equipment, nor fins, just wearing a swimming cap and a close-fitting swimsuit. All he can rely on is a rope, which extends to the bottom of the Dean Blue Hole, which is 202 meters deep. The rope can guide him into the water vertically, after reaching his limit, he can pull the rope to swim up.
  At the beginning of entering the water, he stretched his limbs and floated on the water, adjusting his breathing and mentality. Then he began to dive. His body is almost vertically downward, swinging his body at a small angle, and slowly going downstream. After he swam for a while, the bottom of the sea became dark. The sound and light that can be felt on the land have completely disappeared at this time, and the underwater silence is like death.
  In this case, in addition to stress on the body, fear is also easy to breed in the mind. He tried to maintain his consciousness and told himself to stay sensible. He has stopped swinging, because he can sink without exerting any effort-as his body is compressed, his density increases, and his body can automatically continue to plunge straight under the water. Trubridge was immersed in his own spiritual world at this time. Finally, he touched the tag at a depth of 124 meters, and began to pull the rope to float up. After a difficult parade for more than a minute, he once again returned to the surface and was embraced by everyone, which meant that a new record was born!
  In the field of free diving, Trubridge’s achievements can be described as “unprecedented”, and he is very likely to be “uncommitted”-he is the first person in the world to dive more than 100 meters without assistance. There are 18 world records for various free diving. With so many world records in such a high-risk field, Trubridge feels unbelievable. Someone asked, what secret is hidden in him?
  Why he was so legendary
  Trudeau Bridgetown at 18 months had learned to swim at the age of 8 can dive to 15 meters underwater. As an adult, Trubridge is 1.85 meters tall, has a lung capacity of more than 8 liters, and is strong and slim. But this only shows that he has a natural hobby for swimming and has good physical fitness. However, Trubridge’s body shape, arms, palms, legs and feet are completely normal, and there is no external condition that is more prominent than that of ordinary athletes. His lung volume and red blood cell concentration are also in the normal range, but slightly higher than the average person.
  Some people think that Trubridge’s advantage of free diving may be hidden in genes, and Trubridge is also interested in this statement. So, with his own consent, a genetic testing company called Vitas tested all Trubridge’s DNA.
  Lactic acid is a substance that accumulates in muscles when the muscles are deprived of oxygen, and it causes a burning sensation. Vitas’ chief scientific officer Preston Estep predicts that compared with other athletes, Trubridge’s lactic acid content should be lower because he is good at surviving under hypoxic conditions. But the genetic test showed that the lactic acid level in his muscles was normal, which surprised everyone.
  Another test result is also confusing. General athletes (such as runners and cyclists) will try to increase the maximum amount of oxygen consumed by their muscles per minute (this indicator is called VO2max), which can increase the aerobic respiration of muscle cells and improve the efficiency of energy use. However, due to lack of oxygen underwater, freedivers do not want their muscles to consume a lot of oxygen underwater. But according to the report of genetic testing, Trubridge’s gene has three genetic variants: one is related to lower than normal VO2max, one is related to average VO2max, and the other is related to higher VO2max. Whether VO2max is high or low depends on which variant can be expressed, but Estep’s team cannot judge.
  Fortunately, Estep’s team still discovered two genes that support Trubridge’s athleticism. One of these two genes determines that Trubridge has fewer muscles (his body is thinner), and the other determines that Trubridge’s muscles have greater strength. With less muscle, less oxygen consumption, and greater muscle strength can make up for the lack of muscle mass. But there is also bad news. Genetic testing shows that Trubridge is prone to Alzheimer’s disease. Excessive levels of metal elements in the blood are not conducive to preventing this disease. Trubridge wants to maintain a sports career. It is necessary to supplement iron to enhance the vitality of red blood cells, which is really a painful choice.
  In general, according to the results of genetic testing, not all of Trubridge’s genes support his diving talent. Scientists began to speculate that maybe Trubridge’s diving ability may not come from genes, but from Trubridge’s extraordinary mentality and willpower.
  For many years, Trubridge has followed strict physical exercise methods and meditation training. Mental training is his main advantage, and he does everything he can to remain calm, focused and detached. Thanks to extremely concentrated physical training and strict meditation, even if the pressure of the surrounding sea water becomes greater and greater, and his lungs collapse into the size of an apple, he can walk through the water gracefully like a dolphin. Trubridge’s example tells us: What determines our fate is often the product of acquired training.