An ordinary person can be without air for a maximum of 5 minutes, a trained (freediver) - up to 9 minutes. Then the person begins to convulse, death occurs.
The main danger that lies in wait for a person in the absence of air supply for a long time is oxygen starvation of the brain, which very quickly leads to loss of consciousness and death.
Freedivers are those who like to dive into depths without any equipment. They use various yoga techniques that allow you to train your body and do without air for a long time without harmful consequences.
From such training, changes occur in the body that adapt a person to oxygen starvation - a slowdown in the heart rate, an increase in hemoglobin levels, and the outflow of blood from the extremities to vital organs. At a depth of more than 50 m, the alveoli are filled with plasma, this maintains the required volume of the lungs, protects them from compression and destruction. Researchers found similar changes in the body in pearl divers who are able to dive to great depths and stay there for 2 to 6 minutes. Incredibly, in Japan, only women sink to the bottom for seafood.
One of the amazing records of 17 minutes 4 seconds underwater, without any equipment, was set in May 2008 by the American illusionist David Blaine live on the Oprah Winfrey talk show. Before diving, he breathed pure oxygen for 23 minutes to fill his lungs and lower the concentration of carbon dioxide in the blood.
In October 2008, the Italian diver Gianluca Genoni managed to appear in the Guinness Book of Records. He spent 18 minutes 3, 69 seconds underwater without a mask. Thus, he beat the achievement of the German diver Tom Sietas, who held his breath for 17 minutes 19 seconds in September of the same year. The participants, according to the rules, were allowed to breathe pure oxygen for 30 minutes before attempting.
By 2010, the record was inexorably approaching 20 minutes. In February, a resident of Zurich, Peter Kolat, was in the Guinness Book of Records with a score of 19 minutes 21 seconds. The record was set at an exhibition in St. Gallen.
On April 1, 2010, freediver Stig Severinsen set a new world record. In the research center Kattegatcentret, the city of Grena (Denmark), in the oceanarium of tropical sharks, Severinsen spent 20 minutes and 10 seconds at the bottom of the aquarium.
On June 3, 2012, German diver Tom Sitas spent more than two dozen minutes underwater in front of the amazed crowd. The record is 22 minutes 22 seconds.