There's a lot of fear stirred up by the media and supported by the government over the H1N1 influenza virus that's been going around. As with any flu virus, there is a potential for serious complications, but generally speaking this flu is milder than the seasonal flu, except for certain individuals in risk categories. There is a lot of evidence out that exercise can strengthen your immune system, but is exercise enough to prevent swine flu?
The only real answer to this question is... under certain conditions maybe. Being healthy and having a solid exercise regimen is likely to reduce the time it takes to recover from any flu virus, but it may not prevent it. It really depends on the type of exposure you’ve had and how the virus progresses. It's also important to note that those over the age of 60 may already have antibodies to the H1N1 virus and if so, may not get sick.
If you are very healthy, take plenty of vitamins and fluids, and you exercise regularly you may prevent the flu if you have a very weak exposure to it over time. If, however, you get a strong exposure to it you are probably still going to get sick or at least experience flu symptoms. Proper sanitation, especially hand washing/santizing will also contribute greatly to reducing your exposure.
There is something important that you should note, however, when it comes to exercise and your immune system. Regular exercise strengthens your immune system, but very intense exercise temporarily weakens it. Your body needs time to recover from strenuous workouts. This can mean a mild decline in immune function.
I personally find that that the rare times I get sick are after a very strenuous workout that’s weakened my immune system just enough to let the bug get through.
This is not to say intense exercise is bad, but it may not be appropriate if you feel a cold coming on. You don’t need to use a mild allergy symptom as an excuse to skip your exercise, but at the same time if you are getting sick, you should reduce your activity level to conserve energy for your immune system.
There was a time when I wanted to exercise right through illness. And for those highly motivated to stay in shape it's mentally difficult being sick. I believe it's important to rest so you can get back to your exercise routine as soon as you've recovered. If you push it while sick or getting sick you are likely to draw out your recovery time. So if you want to get back to exercise as soon as possible, I suggest you take it easy while sick and start exercising once you've beaten the virus.
You should also make sure you’re getting enough vitamins, particularly Vitamin C.
