Zhang Chengyu is prone to colds and flu in winter, which not only causes sneezing, fever and runny nose, but also makes the cold weather a nightmare for the elderly and children with weak resistance. Although moderate exercise can enhance resistance and help prevent colds and flu, it is chilly outside, and it is easier to catch a cold and get sick if you are not careful. What shall we do? Dr. Japanese Sports Science suggested that doing simple indoor exercise at home can improve resistance, and may also have slimming effect of improving muscle strength and promoting metabolism! Cold weather, low body temperature, easy to get sick, strong immunity will not catch a cold at home. Araki Bangzi, Ph.D., School of Sports Science, Waseda University, Japan, pointed out that the temperature difference between indoor and outdoor is large in winter, and dry air is easy to dry the nasal mucosa, which will make the virus take advantage of it and make people more likely to catch a cold and get sick. In addition, the elderly usually have weak immunity, and once they catch a cold, they are particularly prone to serious diseases such as pneumonia and even life-threatening, so we should not be careless. Therefore, Araki Bangzi suggested moderate exercise to raise body temperature, which not only helps to improve immunity, but also can exercise muscle strength and burn fat, stay away from obesity. Because the outdoor temperature is low, there are many germs, and the risk of being infected by others is high, it is advisable to use indoor exercise to easily promote blood flow, raise body temperature, exercise muscle strength and improve immunity. Dr. Ishigaki, the authority of Japanese health care medicine, also pointed out that every drop in body temperature 1 degree will reduce immunity by 30%, which will increase the chances of catching a cold, pneumonia, diabetes, myocardial infarction and cerebral infarction. In contrast, when the body temperature rises 1 degree, the immunity can be temporarily improved by about 5 ~ 6 times, which can effectively improve the resistance and avoid getting sick. Araki Bangzi recommends simple indoor exercise, which can also help to exercise the muscles around the hips and legs. Hiroyuki Higuchi, president of Higuchi Bone Institute in Japan and a judo reconstructor, also said that many middle-aged and elderly people will suffer from knee pain and low back pain due to stiff hip joints, so exercising the muscles around hip joints will help prevent pain. Doing activities at home in cold weather helps to prevent diseases and exercise muscle strength. Bend your knees slightly, move one foot to the side, and then move your feet together for lateral movement. At the same time, pay attention to the height of the head when moving, move back and forth for 4 steps as a cycle, and do 1 ~ 3 cycles. Skipping rope in the air is an aerobic exercise. As long as you hold the tubular body in the plastic wrap with both hands and imitate skipping for 30 seconds, you will get the exercise effect after doing it for 2 ~ 5 times. After getting used to it, you can increase the number of times, or move back and forth left and right while changing the center of gravity, and the effect will be better.