You know that vaccines can prevent disease—and so can exercise to a certain degree. But can you combine the two? Is it okay to head to Zumba, sweat a few miles out on the treadmill, or lift weights after your flu shot? What about when you’re receiving the COVID-19 or pneumococcal vaccines or, really, any vaccine at all?
Medical experts say exercise after vaccines is fine, as long as you’re feeling up to it.
“There is no contraindication [a reason not to do something] to exercising on the day of or the days after you receive a vaccine,” says William Schaffner, MD, a professor of infectious diseases at Vanderbilt University School of Medicine. “There’s nothing that exercise is going to do that in any way impedes your immune response. But be sensible and listen to your body. Some people respond to vaccines with fatigue, muscle aches, and sometimes a fever. The day you receive a vaccine may not be the day to try and set a personal record.”
Vaccines and your immune response
Vaccines help initiate immunity to a certain germ, such as a virus. Because they contain weakened or inactive parts of a virus or bacterium, vaccines trigger the immune system to create antibodies and T-cells—two weapons the immune system uses to recognize and fight foreign invaders. The stronger your immune response to that vaccine, the better protection it offers.
Can exercise after vaccines improve immune response?
If exercise doesn’t hurt your immune response to a vaccine, can it actually help it? The data is mixed, and the results can vary depending on the age and gender of study subjects, which vaccines they get, and the type, duration, and timing of the exercise they performed.
For example, one study looking at healthy young adults found that those who performed 15 minutes of exercise with resistance bands prior to receiving the pneumococcal vaccine had an enhanced antibody response. But the response was only significant in those who received a half-dose of the vaccine, versus a full one. Other research published in the journal Frontiers of Immunology found that a single bout of exercise can enhance the immune response to vaccinations in both young and older study subjects. And researchers from the University of Sydney recommend performing moderate-intensity exercise (such as biking) or resistance exercise (such as weight lifting) immediately before or after getting a flu shot to help activate your immune system’s response to the vaccine.
“Exercise likely increases blood and lymphatic flow, which helps spread the immune cells that are produced post vaccination,” explains Ramsey Shehab, MD, a family practitioner and sports medicine specialist at Henry Ford Health Systems.
If exercise can give your immune response to a vaccine a leg up, what’s the best way to do it? There’s no formal consensus.
In one study, women who exercised their deltoid (upper arm) and bicep muscles prior to receiving a flu vaccine had a better antibody response post-vaccination, while men had a better cell-mediated response (an immune response that involves those disease-fighting T-cells, but not antibodies). Yet another study examined a group of elite athletes and control subjects who were not athletes. Though each group received a flu vaccine and showed a good immune response to the virus post vaccination, those who exercised intensely and regularly (e.g., the elite athletes) had the most pronounced immune response. Those same athletes were studied further. Regardless of when they received their vaccine—either two hours post training or after one day of rest—their immune response (and the number and severity of the side effects they reported) was not significantly different.
“Be sensible, not obsessive,” Dr. Schaffner recommends. “I encourage exercise to the degree that you can, just because it’s generally a good thing to do.”
Exercise after COVID vaccines
Vaccines affect different people differently, and the COVID-19 vaccine is no exception. While there’s no reason you can’t exercise after COVID vaccines, you may not feel like it. According to the Centers for Disease Control and Prevention (CDC), the most common side effects of the COVID-19 vaccine are:
- Swelling and pain at the injection site
- Muscle aches
Most side effects last one to three days and are likely to be more pronounced after receiving your second dose of the vaccine (although more than 50% of people in the vaccine clinical trials didn’t have any side effects).
Serious side effects are rare. A medical professional will observe you for 15-30 minutes immediately after receiving your COVID-19 vaccine to make sure you don’t have a severe allergic reaction to the shot. While the numbers are few, cases of myocarditis (an inflammation of the heart muscle) and pericarditis (an inflammation of the outer lining of the heart) have been reported with COVID-19 vaccination, mostly among young men. “It’s a very small number [who get COVID-19 vaccine-related myocarditis], but using some caution post covid vaccination in young people may be warranted,” Dr. Shehab says.
When to see a doctor for vaccine side effects
Most side effects from vaccines—headache, muscle/joint pain, tiredness, fever, and pain where the injection was given—are mild and short lived. Allergic reactions are extremely rare (occuring in about one to two people per 1 million who receive vaccines). But get immediate medical attention if you’re having any of the following:
- Difficulty breathing
- Swelling of your face or throat
- Rash or hives on your body
- Fast heartbeat
In the end, don’t forgo a vaccination because you think it might affect your workout schedule or your physical performance.
“Just because you may be young, healthy, and physically fit does not mean a virus like COVID cannot make you seriously sick,” Dr. Shaffner says. “We see it every year with the flu and now we’re seeing it with COVID—young, strong people being brought into the hospital and the intensive care unit [with these viruses]. Just being healthy is not enough to ward off a virus. Get your vaccinations.”