Although the H1N1 flu virus seems to have lost its punch, the cold and flu season is still far from over.  There is often a second peak or spike in illness in late January and February, so it is not time to let your guard down just yet.  I have devoted articles in the past to dietary changes and supplements that can strengthen your immune system and help you ward off those nasty viruses, but there is one additional tool you have to strengthen your immune system, and that is good old exercise.  I know, there is that dreaded “E” word again, but the fact remains it is one of the most powerful tools you have to keep you immune system strong and able to keep the cold or flu from gaining a foothold and making you miserable.

Although very intense or prolonged exercise such as running a marathon can actually weaken your immune system, moderate to high intensity exercise that is performed on a consistent basis has been shown to improve the function of the immune system.  Research looking at the duration and frequency of upper respiratory infections asked people to rank themselves as high, medium or low fitness level.  Those in the high fitness levels tended to be regular exercisers and most were normal weight.  The medium level consisted of periodic exercisers and most were overweight, while the low fitness level consisted mostly of overweight or obese individuals who were sedentary.  When comparing the three groups, researchers found that the high fitness level individuals averaged 7.5 days of illness in a 12 week period, the medium fitness group 8.5 days, and the low fitness group 10.6 days during the 12 week period.  Compared to the low fitness individuals, the high fitness individuals had 38% fewer symptoms and rated them 37% less severe, while the medium fitness individuals had 29% fewer symptoms and rated them 28% less severe.  According to the Tamiflu fact sheet, taking the drug at the firs sign of flu symptoms can provide a 38% reduction in the severity of the flu and a 37% reduction in the duration of the illness.  The boost to the immune system from exercise is roughly equal to having that prescription of Tamiflu filled and ready to take of you start to get sick, but I do concede it is easier to just swallow the Tamiflu.   It definitely requires more time and diligence to maintain an exercise routine, but it is an effort that provides a whole host of benefits.  One more thing to consider would be side effects.  Here is the list of possible side effects from the fact sheet for Tamiflu:

Possible side effects: Common: nausea, vomiting, diarrhea, stomach pain, and headache. In children, in addition to above, ear problems or infection, nose bleeds, discharge from eyes and breathlessness or wheezing. Rare: Sudden signs of allergy such as rash, swelling of face, lips or tongue. Chest infection with fever, chills and shortness of breath. Yellowing of the skin, dark colored urine or severe stomach pain. Diarrhea with blood. Patients or their caregivers should look out for signs of abnormal behavior (convulsions, delirium, severe confusion).

Now let’s look at the side effects for exercise:

If you are overweight, losing weight is a probable side effect, enhanced well being and confidence, stronger heart and lungs, improved muscle tone and balance, 27% lower risk of stroke, approximately 50% less risk of type 2 diabetes, approximately 40% less risk of high blood pressure, approximately 50% reduction in mortality from breast cancer, more than 60% lower risk of colon cancer, almost 40% risk of Alzheimer’s or dementia, and it is as effective as anti-depressants in lessening depression 

Even if you can only manage to exercise a few days a week, spending 45-60 minutes doing something will put you in the medium fitness group and more than likely you will pick a few (or more!) of the side effects of exercise.  Additional research showed that walking briskly (3,000 steps in 30 minutes) for 45 minutes 5 days a week resulted in a 25-50% reduction in sick days compared to sedentary controls. 

Your body does not like to be sedentary…it was never designed for long periods of sitting or lying around.  When you treat it in that manor, it breaks down and ceases to function properly, as is evidenced by the dramatic increase in so many chronic (and common) diseases in sedentary individuals. 

Make this the year that you start giving your body what it really needs:  Activity.