Training in cold weather: our tips
This year again, the cold did not have the decency to wait until December 21st to invite one to our country. Not easy to go running when the temperature flirts with negative numbers. First of all because you have to motivate yourself to go out (and stay outside). Secondly, because this time seems to greatly reduce our performance. How to prepare for outdoor exercise in these conditions?
Facing the cold...
Man is a warm-blooded animal, and our body only very moderately appreciates the sensations of cold. As soon as the internal temperature drops below 35 ° C, discomfort follows one another: dizziness, inability to think coherently, loss of consciousness etc ...
So as soon as the body senses a risk of cooling, the blood flow drops and the blood withdraws from the extremities of the body. Blood is one of the only ways for the body to circulate heat: By avoiding heat loss at the "less important" ends of the body, blood protects the main organs (heart and brain in priority).
When the cooling is confirmed, the body begins to shiver: by shaking very quickly the muscles located just under the skin, it allows to warm the epidermis without "wasting" the heat transmitted by the blood and reserved for the organs. The threshold of thermal neutrality is 25°: below this temperature, the body spends energy to warm up. In water, the threshold is 34°.
The food we absorb is used as fuel to produce energy. Part of this energy is used to accomplish a movement while the other allows, in the form of heat, to maintain thermal balance. When the cold persists, we sometimes tend to spend more energy on warming the body. This explains why in cold countries, diets often consist of several light and hot meals throughout the day.
There is, however, a misconception that must be forgotten: fat does not protect against the cold. This is the case in animals that hibernate or live on ice, but not in humans.
Our body loses heat in four different ways:
- Thermal radiation: The difference in temperature between the body and its environment means that the body transmits heat to the air. The greater the area exposed to cold, the more heat loss increases.
- Conduction: Heat loss by direct contact with a colder object. If this object is wet, the heat deficit is multiplied by 5. Only dry clothes protect from the cold.
- Convection: When air comes into direct contact with the surface of the body. The higher the speed of air movement and the greater the temperature difference between the air and the body, the faster the heat loss will be.
- Evaporation of water from the body: Sweating, perspiration (non-noticeable sweating) and breathing (warmed air in the body is loaded with water when it is exhaled).
In cold and dry weather, perspiration helps to maintain a sufficient degree of moisture in the skin. But we don't necessarily realize the dehydration that this causes. However, the decrease in hydration weakens the body in the face of cold.
The minimum is to cover yourself properly. Wearing several layers remains the most effective: the air between the different thicknesses of clothing warms up more than the garment itself. For this, the outer layers should be wider and not compress the air between the layers closest to the body.
The first layer must be insulating and designed to evacuate perspiration. The second must be adapted to external conditions and be easy to put on or remove: you must be able to adapt your outfit to avoid sweating unnecessarily. But it is important not to discover yourself for all that: it is not because you sweat that you should immediately put yourself in a T-shirt. The last layer must protect from the wind.
Do not hesitate to put on a cap: warming the brain allows you to allocate more heat to the rest of the body. Almost half of the body heat is lost by the head... Wearing gloves or using heaters helps to reinforce this effect.
Remember to hydrate often. Thirst is only a symptom of dehydration: You have to drink before! It should also be noted that the consumption of alcohol and coffee affects the body's ability to self-legislate.
Last remedy: Motivation. It's silly to say, but when you're motivated, it's easier to get started and ignore the inconvenience caused by the cold. Organizing group outings avoids withdrawing at the last moment. Not to mention that group work is more motivating.