I was reading my March 2009 issue of "Runners World" magazine and they had a great article on how to stay in shape and fight off germs. They gave the following FIVE ways to fend off germs.

1. Get Your ZZZZZZZs. The more you sleep, the more virus attacking cells you'll produce. According to one study at least 50 percent more after eight hours of sleep than after six.
2. Run Shorter. This is hard if you're training for a marathon type event, but if not 30-75 minutes of moderate activity can boost your ability to fight off the bug, but long hard workouts can do the opposite, so get sleep, take your vitamins and.....
3. Drink Up. Consuming carb-rich drinks before, during, and after a run or workout longer than 90 minutes can restrain immune-inhibiting stress hormones.
4. Recover. Pushing your body without enough rest can weaken your immune response and cause frequent colds. This is hard to do when you're chasing twins around all day. I'm just speaking from personal experience, so do your best to get good recovery from your workouts and take it easy for the rest of the day.
5. Stay Local. If you're really worried about getting sick then race locally. Traveling and taking long trips can subject you to other germs and usually you get less sleep.

Use these tips to stay healthy and be able to keep up with your workouts and goals!