The following methods can be used to enhance physical fitness and resist bacterial and viral infections: 1. Exercise regularly, insist on running for half an hour or walking for one hour every morning. 2. Pay attention to keeping warm in life and increase or decrease clothes at any time according to seasonal changes. 3. Eat more fresh vegetables and fruits, especially those rich in vitamin C and vitamin E. 4. 5.Eat some herbal supplements such as ginseng and deer antler, red dates, water chestnuts, etc. 6.No smoking. 7.Inject the influenza virus vaccine, which can also prevent the flu. 8.Drink more warm water in daily life to speed up the body’s metabolism. 9.Eat some garlic at lunch and dinner, which is good for the prevention of the flu. 10.Go to less crowded and airless public places to avoid infection with bacteria and influenza virus.