The core body temperature at rest is between 36.5 and 37 ° C, our body also ensures the maintaining stable as possible. The hypothalamus is a kind of thermostat charge of this mission. If the blood temperature deviates too much from normal it starts various corrective mechanisms.

Far from the tropics

When the body temperature is too high, Skin blood vessels open (vasodilation) so that it increases blood flow, allowing to evacuate excess heat

Sweating is a second defense mechanism. sweat glands receive the signal to produce the sweat moisten the skin, and whose evaporation evacuate at the same time heat. The reaction of the body is reversed when the body temperature drops too low: cutaneous vessels constrict (vasoconstriction) and reduces heat loss

Another response to cold. Chills, namely small contractions muscle generates heat. Move more or, for example, run a little also helps to maintain a sufficient temperature.

There is one striking difference between the mechanisms set in motion by the body to warm up or cool down. If the former are much less effective than the latter, it is not by chance, after Jan Bourgois, professor of exercise physiology at the University of Ghent: “Human beings are of tropical origin animals and they therefore adapt quickly to a high ambient temperature: 12 to 14 days usually suffice This physiological phenomenon is called acclimatization Things are quite different in cold conditions.. even after prolonged exposure to the cold, it is just a question of acclimatization. The human being is just a little accustomed to the cold, but it is not a physiological adaptation. A fisherman who regularly plunges his hands in cold water simply learns to endure more the impression of cold. Whoever wants to practice cold weather sports should wear suitable clothing and limit the intensity and duration of exercise. ”

Dress otherwise

The choice of suitable clothes is a delicate compromise to find. If you dress too warmly, you will sweat at the slightest effort, and your clothes will get wet; unless they are very well ventilated to allow the evaporation of moisture. This is not a problem as long as you stay active and you produce enough heat but wearing wet clothes, you will cool you faster. The best solution is to dress in several layers to adapt more easily, removing one of the layers when you get too hot and threading into an extra cold conditions.

Manufacturers investing heavily in the development of technical clothing. Until recently, a new type of material has been developed to fit the sports body temperature. When it increases, the textile structure is opened to improve ventilation. It is certainly useful to follow such news, but beware: new technical clothing is often very expensive. Do not buy if the interest of the new material is confirmed.

Cotton is not recommended

In winter, cotton clothes are a form heresy for athletes. In fact, sweating is an almost inevitable consequence of the sport, whether practiced in winter or summer. The quality clothing so quickly absorb sweat, giving the impression of being dry. However, cotton is exactly the opposite: it absorbs a lot of moisture but retains. The suit then sticks to the skin and cools very quickly.

During sporting activity, we must reach 60% of its maximum capacity to keep warm when the thermometer reads 5 ° C and in the presence a just light wind (less than 10 km / h) (1-3). This is not a real problem in appearance. But when it’s really cold, we must produce a much greater effort, and only well-trained people will get there for several hours. Whoever is not able and who wants to practice his sport more quietly cools every time, and cotton will only worsen things. For long winter activities, so always opt for synthetic fibers such as polypropylene and polyester, wool or transformed. However, these fibers can not evaporate sweat if your clothes are not well ventilated.

Protect ends

Children playing outside the soon learn : the ends are very sensitive to cold. In extreme cold, so use protection for the head, nose and ears. Mittens are what is best for hands: they retain heat better than gloves because fingers remain together. Wrap the hands or feet in plastic hoping to keep them dry is anything but a good idea. It is better to take an extra pair of gloves or socks, history always have a dry pair of spare.

Frostbite can sometimes occur at specific locations. Practitioner snowkiting (version “snow” kite-surfing) has seen a freeze of his big toes (4), control of the surfboard to strongly enforce them consistently requiring big toe, which can impair blood flow and thus lead to frostbite. The important lesson for every athlete, especially in winter and in extreme conditions, to think continually every detail that may pose a risk.

References.: bodytalk .be