It is believed that hardened people are less likely to catch a cold and, due to their useful habit, have more good health. We decided to find out if this is so.
The fact that hardening strengthens health is reported by the media ("RIA Novosti","Gazeta.ru","Fifth channel","Championship","Evening Moscow") And sitesdedicated Medicine. Often on the network you can find statements, What hardening Especially useful for children And start it need to From an early life. Even Russian state bodies advise in this way, for example,, for example Administration of St. Petersburg, Department of Labor and Social Protection of Moscow And Rospotrebnadzor.
According to Big medical encyclopedia (BME), hardening is a way to increase the body's stability to adverse external factors. Since thanks to modern comfortable living conditions in cities, many people depend less on the weather changes, the readiness of their organisms is also reduced. Hardening is designed to support a person’s stability to the external environment. In a broad sense, hardening sets include measures to adapt to too high temperatures, ultraviolet light, low atmospheric pressure (for example, before going to the mountains), etc. In most non -academic sources by hardening, they mean the short -term effect of the cold on the human body, and this analysis will also be mainly concentrated on the preparation of the organism for low temperatures and its intended Health benefits. The compilers of the BME are called among the methods used in this type of hardening, cool air baths and wiping or dousing with water (this method is considered more intense due to the greater thermal conductivity of water).
Apparently, you can really accustom yourself to the cold. To maintain temperature in the region of 36–37 ° C in the human body, a protective mechanism: At low temperatures, the vessels of the skin are narrowed, directing the blood to heating the internal organs. However, if the effect of the cold is too long or intense, the body uses a different tactic - trembling, that is, involuntary muscle contraction. Thanks to this, it is possible, having spent energy, to produce heat and protect the body from hypothermia. As evidenced by the results of studies, the reaction of the human body, accustomed to low temperatures, differs: In response to the same strong cold, its vessels do not narrow, the body releases more heat, and the skin holds it better. In general, such a person in the cold feels more comfortable and can avoid hypothermia for longer. However, in order for this effect to be preserved, you need to harden regularly - after a long break, thermoregulatory functions Return To the original parameters. In other words, it is impossible to harden in childhood right away.
Increased frost resistance can be useful, for example, to polar explorers who are forced to spend a lot of time in the cold in duty. An ordinary city resident does not need to be on the street for so long at low temperatures, the risks of getting severe hypothermia or frostbite from him are much lower, therefore it is not so necessary to prepare your body for severe frosts. As for other possible unpleasant consequences from staying in the cold, the cold itself Can't cause cold diseases (as, by the way, and meningitis), they are caused by pathogens that have fallen into the body that immunity could not overcome.
There is an opinion that low temperatures negatively affect the operation of the immune system, which is why a person in winter becomes more prone to various kinds of colds. The scientific community has not yet reached a consensus regarding the veracity of this statement. There are a limited number of studies that testify in favor of this theory. So, for example, in 2017, scientists from Thailand found outthat cells stored at +25 ° C are worse producing cytokines (substances that provide an immune response to pathogens) than at +37 ° C. However, this study was conducted in vitro, that is, in laboratory conditions on individual cells. If the cells in the human body are cooled to +25 ° C, a possible cold will be the smallest of problems, since risk Death occurs already at body temperature at +32 ° C. In order to prevent this, the body has a protective mechanism, which was mentioned above. So it is not entirely clear whether it is necessary to “train” the body to resist low temperatures, since there is no unambiguous answer, whether they affect a person’s susceptibility to the pathogens of colds.
In winter, people really get sick more often, however Related This is not so much with frosts as with the fact that at minus temperatures air It becomes The more dry on the street and in the premises (it holds water vapor in itself worse than warm, and inside the buildings it is also aggravated by heating). Through dry air with microbes easier spread. When a sick person sneezes in conditions of high humidity, the aerosol, released from his nose and mouth, is associated with moisture in the air, forming larger drops that settled faster to the ground. If the air is dry, this aerosol populated by microbes remains in the air longer, which means that others have more chances to breathe it. In addition, in winter, due to a short daylight day and the reduction of the time spent by people on the street, many have a shortage vitamin D, since it is produced in the body under the influence of sunlight. In addition, in closed spaces in people, the risk of facing viruses and bacteria than in the fresh air is higher. Hardening will not protect from these factors.
In 2016, Dutch scientists conducted experiment. 3000 subjects without hardening experience were divided into four groups. Three of them were supposed to take a contrast shower for three months daily (the duration of the cold phases varied from 30 to 90 seconds depending on the group), and the fourth participants should not take a contrast shower during the first month, and in the next two months to also include it in their daily routine, but independently determine the duration of the effect of cold water. Three months later, the researchers compared how many times the subjects during the experiment did not go to work due to illness. It turned out that the participants from the first three groups who took a contrast shower for three months according to certain recommendations were sick less often than the control group. However, oddly enough, there was no statistically significant difference in the number of days spent on sick leave, between representatives of four groups was not revealed.
There is also a scientific community opinionWhat to strengthen the body's immune response and its manifestations (wound healing, the fight against viruses and infections, etc.) can short -term stress. However, we are talking not only about stress related to the cold, but also about any other - psychological or physical. For example, short -term physical stress for the body can be achieved using sports. Most likely, a tempting person will generally lead a healthier lifestyle, including not neglecting physical exercises, so it is difficult to talk about the effect specifically from systematic contact with the cold. This is evidenced by the results experimentPublished in 2015 by scientists from the UK. For 44 pairs of subjects, consisting of a swimmer and who does not know how to swim, was observed for 13 weeks. At the same time, about half of the swimmers preferred to train in the pool, and the rest in natural reservoirs, where the temperature of the water is noticeably lower. During the experiment, the participants reported daily about their physical activity and health status. As a result, it turned out that the swimmers were generally sick less often than their research partners who did not know how to swim, but there was no statistically significant difference in the incidence and severity of the disease between the fans of the pools and those who preferred cold water.
“Verified” failed to find any serious contraindications for gradual hardening, so even if it does not bring significant benefits, it is at least safe. However, the keyword here is “gradual”. In some sources, even swimming in ice water is attributed to hardening methods, but an unprepared person, plunging into water with a temperature of +10–15 ° C, can get Cold shock And die. The compilers of BME Consult Start daily hardening with water at a temperature of +34–35 ° C, then reduce it by 1 ° C every seven days, gradually bringing to +22–24 ° C. In the absence of a negative reaction of the body, after months of such procedures, the water temperature can be reduced to +10–12 ° C. As for hardening with cold air, experts also do not recommend sharply exposed to low temperatures: you need to start with +14–15 ° C for 3-5 minutes. per day. People with cardiovascular diseases should be hardened with special Caution.
Thus, judging by the data available for today, hardening can be useful to people who are forced to spend a lot of time in the cold - for example, polar explorers or some athletes. Low temperatures themselves cannot provoke a cold or other infectious diseases, and convincing evidence of the negative effect of the cold on the work of the immune system is not yet enough to consider the accustoming the body to it with any necessary. Apparently, short -term stress, including temperature, can stimulate the operation of the immune system, but hardening is far from the only way to achieve this. At least for a healthy person, hardening procedures are relatively safe if you enter into their lives gradually.
Photo on the cover: pexels.com
Read on the topic:
- Healthline. Cold Shower Benefits for Your Health
- Is it true that immunity is falling in the spring and it needs to be raised?
- Is it true that the air conditioner can cause a cold, tonsillitis, neuralgia, pneumonia and headache?
- Is it true that if you walk in the winter without a hat, you can get meningitis?
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