Question: Our senior family feels so fortunate to get our second jab of Pfizer vaccine next week. We are reading conflicting info in NYTimes and WebMD about aerobic exercise before and after. You dig a good workout, I know. Your thoughts? Should we skip the zoom Pilates/weights the hour after the jab?
Answer: Short answer: I recommend keeping up with your regular exercise routine as long as you feel good.
Longer answer: I was surprised that there was conflicting guidance in this space, so I took some more time to read up. Obviously, we know that being fit and regularly exercising is good for your health. Accumulating evidence also shows that “physical activity promotes a strong immune system and better vaccine responses.” And there’s a whole set of research aimed at understanding whether the timing of exercise– either soon before or soon after vaccination– can reduce pain associated with vaccination, improve antibody response to the vaccine, and/or reduce the occurrence of side effects associated with the vaccine. In my relatively quick skim of related scientific articles in pubmed, I found that there’s nothing that indicates exercise is harmful either pre- or post-vaccination; rather, studies indicate that exercise is either beneficial or has no influence (for example, see here, here, here, and here). Having confirmed my original understanding, I became even more confused why anyone would express any doubts about exercise… so I read a little more. And I think the issue is as follows: because there have been some rare cases of severe allergic reactions after COVID vaccination (CDC estimate is 11.1 cases per million doses of Pfizer vaccine); and because exercise has also been rarely associated with severe allergic reactions; a doctor WebMD interviewed connected these dots and suggested that people avoid exercise after vaccination to reduce possibility of severe allergic reaction. The problem with this advice is that it is an overinterpretation of the evidence to date.
A few more notes: There are recommendations that children with egg allergies who are at high-risk of anaphylaxis (due to egg-based vaccinations like influenza) “should be observed for 60 minutes and restricted from strenuous exercise for one day.” To my knowledge, that’s the only relevant exercise/vaccination recommendation; there have not been cases of exercise induced anaphylaxis associated with the Pfizer or Moderna vaccine; and individuals with a history of severe allergic reaction are precautioned against and in some cases contraindicated for receiving the Pfizer and Moderna vaccines. A well-respected doctor, Dr. Peter Hotez, recently responded to the claim that a person should avoid exercise before getting the jab, affirming that individuals should “Keep up with your regular exercise routine. It’s really important, especially in this time of Covid.”