There's not a lot that can keep me from running, but I am currently suffering from an unbeleivably painful earache that has really got me down. I am off balance... can't hear in my left ear at all. Yeah - this is keeping me off the road.
Thankfully, these kinds of things don't happen too often, but as the flu season ramps up sooner or later it's going to happen...that scratchy throat, sinus pain, runny nose AUGH! You're sick in the middle of training, so what do you do? Run through it? Take a few days off? A lot of people wonder whether or not it's OK to train while you're sick, so here's the general rule:
Use the "neck check." If all your symptoms are above the neck, it's generally OK to run, Fever and chest congestion are indications that you need to take a couple of days off to allow your body the rest and recovery time it needs. If you have a stomach ailment and have been either vomiting or have had diarreah, be very careful in terms of hydration and definitely take time off to regain strength. Be sure you have been consuming enough liquids (do the "pee test"). Use common sense and don't push yourself too hard.
I have personally found that running with a cold actually makes me feel better, but everyone is different. I actually ran my very first race with strep-throat; definitely NOT recommended.
Take care of yourself - get plenty of rest, eat right and wash your hands frequently. Hopefully you'll make it through the cold and flu season unscathed! Runner Felix Wong has some great tips for staying healthy and on the road - including a home remedy involving a raw onion! I don't know about the onion, but all his tips make a lot of sense to me, especially the part about keeping your house clean.
Let's stay healthy and strong and ready for a great spring season, but if you do end up with the cold or flu, remember "the neck!"