Can exercise help fight the flu? Some surprising answers


By Dr. Grant Lum

Well, I hope that you’re ready for yet another flu article. This one doesn’t talk about government mishandling of the crisis, or vaccine shortages, or the dangers of adjuvant. It’s about exercise.

Many of us have the belief that by being healthy, including exercising regularly, we can avoid illness, or at least reduce our likelihood of getting sick.

A review of various studies looking at exercise and the immune system in older adults was published in the Clinical Journal of Sport Medicine in 2008. Unexpectedly, it showed that the evidence is a bit conflicting.

One study showed that regular aerobic exercise might enhance “immunologic memory” after vaccination. In other words, exercise might help the vaccine work better, in the same way the adjuvant in the H1N1 vaccine is supposed to help.

Several other studies reviewed showed that endurance training, or endurance and strength training combined, did not reduce viral infections, including flu. But there were seasonal and time of day variations in the study, and the numbers of subjects in the studies were small, making it harder to detect an effect between the exercise and the non-exercise groups.

A recent study from the UK, published in October in the journal Brain, Behaviour and Immunity , showed that a single bout of resistance exercise just prior to receiving the seasonal flu vaccine had no effect on the immune response of those who received the vaccine.

Another study published this month in the Journal of Infectious Diseases showed that regular exercise reduced the effects of influenza on those affected. The only problem with the study is that it was done on mice! So we can conclude from all of this that exercising regularly might help mice recover from the flu faster, but for us humans, the jury is out.

In general, exercise is good for you. As physicians, we believe that the healthier you are, the more likely you are to resist infection, and that when infected you’ll have a lesser infection. Although the evidence isn’t clear, I’m still recommending exercise to my patients! (CTV)