Running is a popular sport. We would exercise to different extent to different weather, this not only exercise will, but also body healthy.
To the cold weather, because of the cold air, body has some special reaction to the cold by change hematopoietic, they are immune to many diseases. So runners running in winter are not likely to trouble with anemia, colds, bronchitis and pneumonia. Cold generally with weaker sunlight; outdoor running can make up the sun. And sunlight correspond will promote the absorption of calcium and phosphorus, this is key factor to the growth of bones. Sun’s ultraviolet rays can kill the bacteria on the clothes and body; the human body can act as a “disinfectant”.
