As per the Centers for Disease Control and Prevention (CDC), the COVID vaccine may have some common side-effects. After getting the shot, a person may experience pain, redness, and swelling on the arm where you got the shot. Apart from that, tiredness, headache, muscle pain, chills, fever, and nausea are also common. These signs are proof that your vaccine is developing immunity against the virus. Some people may have mild symptoms, while others face great difficulty after getting the shot. No two cases are the same. So it is difficult to say what you should do. If you feel tired and nauseated, it is better to avoid work out to prevent the risk of injury.
It is impossible to predict how your body will respond to the vaccine. But as per general observation, younger adults (in the 45 and above age group) are more likely to experience frequent side effects because their immune systems respond to the vaccine more vigorously than older adults.