In winter, due to the cold weather, especially outdoors, the human body temperature is low, which leads to the decrease of the ductility of the muscles and bones of the body, which makes it easy to get injured. Therefore, it is necessary to fully exercise before exercise, so that the muscles and bones can fully move, ensure activities and reduce injuries.
For a real example, in early June and February of 5438, the climate in the north was already very cold. At noon, the unit has a friendly football match. During the game, a player did not have physical contact with others and injured his knee while running. Finally diagnosed as fascial tear. This is the most direct manifestation of not fully warming up.
In fact, whether it is winter or summer, exercise should be fully warmed up, and it is important to stick to it and have a solid physical foundation. Don't blindly "disorderly" exercise, for example, if you want to run 5 kilometers on a whim, it will not play a role in strengthening your body and you will be easily injured. What's more, it will cause endocrine disorders because of sudden heavy exercise.
In short, we should warm up before exercise and replenish water after exercise. Exercise is a lasting thing and needs our ruler to stick to it horizontally.