New Study Shows Moderate Exercise on the Day of a Flu Shot Enhances its Effectiveness

In a pilot study at Iowa State University, college students who took a moderately paced 90-minute jog or bike ride 15 minutes after receiving their flu shots exhibited nearly double the antibody response of a sedentary group that sat quietly for 90 minutes after their flu shot.  The exercising group also had higher blood levels of immune system cells that help the body fight off infection, study author Marian Kohut told the New York Times. Intriguingly a 45 minute run did not have the same immune boosting impact as a 90 minute run.90 minutes on an exercise bike can increase the effectiveness of a flu shot.

In a previous study, sedentary elderly people who embarked on a routine of exercise 10 months prior to getting the flu shot had improved immune responses to the vaccine. Earlier research showed that 20 minutes of bicep curls before the flu shot also enhanced its activity. 

Researchers have not yet teased out all of the biological mechanisms of the exercise effect, but the researcher's current best guess is that the exercise "probably sped blood circulation and pumped the vaccine away from the injectin site and to other parts of the body. "The exercise probably also goosed the body's overall immune system," Dr. Kohut told The Times, "which in turn helped exaggerate the vaccine's effect."

A nice long jog or ride after a flu shot will increase its effectiveness. Other studies have established that sleep deprivation can rob a vaccine of effectiveness in the short term, although the body apparently catches up.

To optimize a vaccine, take a long moderate jog or bike ride and get a good night's sleep.