Flu season has started — and with the rates of the H1N1 virus increasing, people are looking for ways to boost their immunity. Scientists have been examining the association between exercise and immunity for several decades. Their theory so far is what they call a “J-shaped curve” for exericse and immunity. The risk of catching a cold or the flu and of having a particularly severe form of the infection drop if you exercise moderately. But, the risk of catching an illness and becoming very sick jumps when you exercise intensely (breathing especially hard) for a long duration (an hour or longer). Interesting news for those running marathons in October at the start of the flu season. If that is you, be sure to avoid sniffling friends and family and wash your hands often for several days post-event.
Moderate, consistent physical activity strengthens the immune system by temporarily boosting the macrophages, or cells that attack bacteria. This holds true for those with young or aging immune systems. In one research study, people who walked at 70-75 percent of their maximum effort for 40 minutes per day had half as many sick days due to colds or sore throats as those who didn’t exercise. One more way to protect yourself this flu season!
More information, check out NY Times Health: Exercise and Immunity