There are no clear rules on how long to engage in strenuous activities after vaccination, and it is necessary to decide according to your own situation. The main reason is to avoid infection at the inoculation site and to avoid catching a cold after exercise.1. More sweat will be discharged after strenuous exercise, and the sweat flowing through the inoculation site may lead to infection. In addition, the fusion of a large amount of sweat and skin metabolism keratin after exercise can cause itching of the skin and raise the desire to take a shower. Once the inoculation site is wet, it will increase the risk of infection, so it is not recommended that vaccinators exercise vigorously for a short period of time. 2. After exercise, a large amount of sweat remains on the body surface, and the pores of the body are also in an expanded state, at which time you may catch a cold if you encounter cold or wind. Symptoms such as shortness of breath, accelerated heart rate and fatigue will also occur after exercise, which will aggravate the adverse reactions after vaccination; 3. Strenuous exercise will lead to a decrease in immunity, and the body is receiving stimulation from foreign antigens and is itself in a turbulent period of immunity, with the risk of producing a harmful immune response. If this is combined with the factor of decreased immunity, it may add insult to injury. It is recommended to choose relatively soothing exercises after vaccination, such as walking, yoga, tai chi, etc. Proper exercise will strengthen the body and will not have an effect on the effectiveness of the vaccine.