After the hepatitis B vaccination, you can do normal activities and exercise appropriately, but strenuous exercise is not recommended. If you exercise vigorously, there may be: 1. The immunity of the body will be reduced after vigorous exercise, and the patient may sweat a lot after exercise, so he may catch cold and flu easily because of the weather. 2. The titer of hepatitis B surface antibody may be affected after vigorous exercise, because the immunity of the body is reduced after vaccination, and then vigorous exercise may cause the immune response of the body to be reduced and affect the titer level of hepatitis B surface antibody production. 3. After strenuous exercise, the body may sweat a lot and the wound of hepatitis B vaccination may not heal in a short time, which may increase the chance of local infection and lead to redness, swelling, pain and fever in serious cases.