There are many different kinds of shots with varying side effects, though there is no medical evidence that indicates exercising after getting a shot is harmful. In fact, exercising boosts your immunity and may help you fight the infection, illness or disease the shot was given to prevent. For example, an article on the Rice University Wellness Center website indicates that those who exercise moderately before and after a flu shot develop a higher immunity. Since different shots have different side effects, talk to your doctor about your desire to exercise after getting a shot.
You may have to perform a less-intense version of your normal exercise routine so you don't feel sore and feverish. If you exercise too hard when you don't feel well, it may cause fatigue and damage your immune response. However, if you do not feel ill, you should go ahead and exercise. Some studies have shown that cardiovascular exercise can actually improve the immune system response for better protection from certain vaccines, such as the flu vaccine. Side effects from shots usually last one to two days. When they subside, you can continue your normal activities.
Keep your injection site bandaged while you exercise. This may help reduce discomfort during your exercise routine if you are experiencing pain and inflammation.
Drink plenty of water when you exercise so you don't become dehydrated. Water can help your body heal and quickly recover from mild fever and inflammation.