If you’ve put off getting a flu shot until now, when your coworkers are dropping like flies, read on before rolling up your sleeve.
Wait, work better? That’s right—the flu shot isn’t a 100 percent guarantee that you won’t get sick. The vaccine only blocks infection 50 to 70 percent of the time. The more antibodies your body develops in response to the vaccine, the stronger the defense you’ll have against the flu, but some people don’t produce as many antibodies as others. Luckily, exercise can help.
To get the most punch from that prick, get sweaty right after you get a flu shot. In an Iowa State University study, volunteers went on 90-minute moderately paced runs or bike rides 15 minutes after being vaccinated. A month later, these study participants had nearly double the antibody response compared to volunteers who had sat quietly for 90 minutes following the vaccine. The researchers suggest that aerobic activity speeds up circulation and helps pump the vaccine away from the injection site to other parts of the body.
Sure, an hour and a half may seem like a pretty demanding cardio session, especially if the bulk of your gym time is typically devoted to weights, but 90 minutes appears to be the magic number. When the Iowa State researchers conducted a similar experiment on mice, the rodents that ran on a wheel for 90 minutes had a better antibody response than those who ran for 45 minutes or 180 minutes.