6 Gentle Exercises to Reduce Arm Soreness From the COVID-19 Vaccine

When it comes to the COVID-19 vaccine, some arm soreness is well worth the protection. But that doesn't necessarily make your shoulder any less achy.

According to a February 2021 article in ​Nature,​ after receiving the Pfizer-BioNTech vaccine, up to 75 percent of people experience pain at the injection site. After the second dose, 27 percent have some swelling. And while you've undoubtedly felt some post-shot shoulder aches in the past, arm discomfort tends to be greater after the COVID-19 vaccine than after the flu shot, according to the article.

Fortunately, you can easily mitigate the COVID-19 vaccine side effect. One simple way is with gentle arm exercises, according to the Centers for Disease Control (CDC). These six shoulder moves, courtesy of Rachel Volkl, PT, DPT, a physical therapist at Rush University Medical Center in Chicago, are perfect for getting the job done.

"Start the exercises ​before​ you develop muscle soreness in order to minimize this side effect," she says. "Many vaccination sites require that you sit in an observation area for 15 to 30 minutes for monitoring after receiving your dose. Feel free to begin with a few of these exercises while you're there."

From there, continue doing 5 to 10 reps of each move roughly every hour for one to four days, or until the achiness lets up. You can perform them with only the arm that received the injection or, if you're into symmetry, with both arms.

Get tips on how to stay healthy, safe and sane during the novel coronavirus pandemic.

Some arm soreness after vaccination is totally normal. It's part of your body's natural response to a needle piercing of your deltoid as well as to the chemicals within the syringe.

According to the CDC, post-vaccine discomfort is a sign that your body is building protection against the novel coronavirus. "Inflammation is a normal part of your immune system's response to developing a defense," Volkl says. "Your immune system activates chemicals to help respond to the vaccine, which can result in localized swelling and pain in the area of the injection."

That said, if you don't have a sore arm after the COVID vaccine, it doesn't mean the vaccine didn't work. So consider yourself lucky!

Both the Pfizer-BioNTech and Moderna vaccines are Messenger RNA (or mRNA) vaccines. The CDC explains that they work unlike many other vaccines, which deposit a weakened or inactive virus into the body. Instead, mRNA vaccines teach our cells how to make a protein (or a portion of a protein) that will fight off infection if we are exposed to the virus in the future.

"There doesn't seem to be a clear-cut explanation as to why COVID vaccine recipients experience more soreness than routine vaccines, but it could possibly be because mRNA vaccines have preservatives and stabilizers that are unique to them, namely polyethylene," says Magellan Yadao, a doctor of pharmacy and vaccine coordinator at St. Bernard Hospital in Chicago.

"Also, this might be a little speculative, but COVID-19 is really novel, and the bulk of the human population hasn't been exposed to either of them," Yadao says. "So one could make the argument that our immune systems are completely naive to this virus and its antigens."

Basically, since both the virus and its vaccine are so unfamiliar to the human body, it might be causing more irritation than a routine vaccination would.

To date, no research has investigated why movement might limit the extent of vaccine-induced muscle tenderness. "But there are a number of theories about how light exercise can minimize soreness following heavy exercise," Volkl. And they likely apply to arm soreness after the COVID vaccine. After all, both are signs of micro-trauma within the shoulder muscle.

Here are some reasons gentle exercise may help you feel better faster. Just keep in mind that the operative word here is ​gentle​. "It's important not to overdo it by completing a heavy upper-body workout, as this may exacerbate soreness," Volkl says.

​It Boosts Blood Flow:​ The microscopic injury to your deltoid results in metabolic byproducts that can spur discomfort But moving your in-pain muscle increases blood flow to the area, helping to remove those chemicals from your body and ease arm aches, Volkl says.

​It Gets Your Endorphins Going:​ The exercise high is real. "Endorphins released during exercise can temporarily reduce the brain's interpretation and experience of pain," she says.

​It Has Anti-Inflammatory Effects:​ "Active muscle contractions that occur with light movement may potentially disperse localized edema, or swelling, to some extent," Volkl says. A March 2017 study in ​Brain, Behavior, and Immunity​ found that a single 20-minute session of moderate exercise acts as an anti-inflammatory.