A person's apnea limit depends on the amount of oxygen in the blood, but it is the high concentration of carbon dioxide that makes people feel the urge to breathe.

For most untrained ordinary people, the so-called apnea limit is not that the body's oxygen content is too low, but that the carbon dioxide concentration is too high, so most people's apnea limit is only the limit of their patience, which is still far from the body's apnea limit.

Therefore, several factors that affect the duration of apnea, the initial oxygen content of the blood, the oxygen consumption during apnea, the tolerance to carbon dioxide, and the limit value of hypoxia have become the focus.

At this time, he controlled his body in front of the circular hole, and tried his best to keep himself motionless, only his hands and feet gently swinged, and slowly adjusted his mentality to avoid his cranky thoughts.

He still understands that the brain increases the amount of energy it consumes when it thinks a lot, not to mention that people can only fully break down nutrients such as sugars, lipids and proteins into energy when they get enough oxygen.

A desire to open his mouth and let go of his nostrils to breathe had gradually appeared, and slowly became stronger, and he knew that he had reached the limit, that is, the tolerance of carbon dioxide had reached the limit.

Picked up the flashlight in his hand and shone it on the opposite side of the annular hole, and after confirming that there should be no danger, Zhang Yang controlled his body and slowly swam through the annular hole.

A path that had also been carved into the rock face appeared in the light, but luckily the circular path in his sight was now extending upwards and seemed to be getting wider and wider.

......

"Director, Zhang Yang said that it was too dangerous for us not to go over, what should we do?"

At the third of the mountain beam where Zhang Yang set off before, the security captain and several members of the security team of the scenic spot followed the person in charge of the scenic spot all the way to come here, and they heard what Zhang Yang said in the live broadcast room to tell them not to go up the mountain.

The one who is called the director is a middle-aged man, who wears glasses, but if you don't look at this guy's figure, he originally looked like a scholar with white and tender glasses, but this guy's sturdy figure below the neck stretched his clothes bulging, and immediately gave people a feeling of a strong man.

"No, I'll go up and take a look, you haven't climbed the mountain, just guard below, and show them the way when the rescue team comes!"

After saying this, the director actually unbuttoned his suit, and then in the eyes of the security captain who was still relatively calm but the other team members were dumbfounded, he casually threw his shirt over, and then opened the backpack he had taken.

In less than a minute, an 'elite warrior' wearing jungle camouflage combat boots appeared in front of everyone's eyes, and even the gold-rimmed glasses hanging from his ears were taken off and thrown to a security guard.

A group of security team members looked at the director who was carrying a small backpack and quickly climbed up the mountain beam, and they became stunned one by one, and couldn't help but wonder in their hearts, is this still the director who usually looks kind and can even be topped by them?

"Captain, director, what is this?"

A security guard who helped the director hold the golden glasses saw that his captain's expression was quite calm, as if he knew something, so he simply asked.

Unexpectedly, hearing the inquiry of this subordinate team, the security captain glared fiercely at the team members he brought over.

"You one by one, don't think that I usually don't know that you are talking about our director in private, what looks five big and three thick but is a sissy, you know a fart.

When Lao Tzu was in the reconnaissance unit, our director had been in the special combat team for three years, and he had been an instructor for me several times.

Okay, let's get ready to withdraw, although I don't watch that flamboyant live broadcast, and I don't know what his strength is, but our director is not weak, okay, it's easy to save this anchor. ”

......

Zhang Yang naturally didn't know that there was a special combat team member who had been through a hundred battles and didn't listen to the advice to come to the rescue of him, and he breathed fresh, humid and cold air again, and just carried out an extremely rapid self-'warming', so that his body, which had been shivering from the cold and biting river water, began to regain a little temperature.

Taking the drone out of his backpack again, and turning on the drone's searchlight, he began to sit up on the spot again and raise his legs to maintain his body temperature, of course, this way of resisting the cold must also be carried out under the condition of full physical strength, otherwise the low temperature around you will instantly make your body temperature even lower when you sweat.

At least according to Zhang Yang's understanding, when the human body is exercising, the total heat production can be up to 10~15 times higher than that when it is quiet, and skeletal muscle becomes the main heat-producing organ at this time, especially in the most intense exercise, the heat production of skeletal muscle accounts for more than 90% of the total heat production.

Due to the sharp increase in the metabolism of substances in the muscles during exercise, the heat production increases greatly, and although the heat dissipation process is strengthened by the regulation of the nervous system, it still lags behind the thermogenesis process, so the body temperature rises.

He is now using this principle, quickly increase the body surface temperature, so that he feels not so cold, but this kind of exercise you really have to continue, once in the low temperature environment this exercise interval is longer, the heat brought out by the sweat will quickly dissipate in the low temperature environment, at that time people will also feel cold, even colder, that is because the sweat on his body is not wiped clean, and there is no towel in his hands to wipe the sweat.

I have to say that the automatic body temperature regulation function of the human body is very peculiar, and often exercising under low temperature or high temperature environmental conditions will make the body's body temperature regulation ability stronger.

People who have a good ability to automatically regulate body temperature can quickly strengthen the heat production process and reduce heat dissipation after exercise under low temperature conditions, and quickly strengthen the heat dissipation process after exercise under hot environmental conditions.

But all this must be often outdoors for exercise, or adhere to cold baths, winter swimming, etc., but not easy to get cold, this is because there is often a large gap between body temperature and environmental temperature, the human body sometimes encounters high temperatures, sometimes encounters low temperatures, so that the body temperature regulation function is exercised, and the ability to adapt to high temperature and low temperature environment is improved.

And Zhang Yang is now in this state, he often conducts live broadcasts outdoors, has experienced the scorching sun, has also experienced ice and snow, has been to the hottest place in China, and has been to the coldest place, and often in the wild, it can be said that his body temperature automatic regulation ability is still very strong, if there is a dry towel on his body at this time, wipe off the sweat he just made, and through this exercise, he can also keep his body temperature constantly.