It's cold and rainy outside... all is well until suddenly you are down for the count with a cough that just won't go away and a runny nose that seems to be connected to a running faucet. It's cold season. And you've got one. So the question is: do you work out?
Unfortunately there is no simple answer. But before we get to that, you should remember that any public space (e.g. a gym) is a germ jamboree during cold season. People bring them in from their kids' schools, from their jobs, and all sorts of other places. Simply washing your hands or using hand cleaner throughout your day can significantly decrease your chances of even having to worry about working out sick - because you won't get sick.
But back on track - to work out or not. Let's talk about a typical head cold. If it's a cough, sore throat, sinus pain, sneezing, sniffles and that sort of thing, then it is fine to work out (without sharing!!)... so long as your cold isn't in conjunction with bad asthma or sluggishness. Make sure you take the intensity down a notch while working out and pay extra care to your nutrition and up your hydration.
Now if you have a fever on the other hand, or if you have cold symptoms from the chest down like chest congestion or muscle aches you might want to give yourself the day off. When you start to have fluish symptoms, working out can do more harm than good. Even medicated, you need rest. Decongestants, for example, combined with intense workouts, can be dangerous, hard on the heart and make you more ill rather than allowing your body to focus on healing itself.
The bottom line is you need to listen to your body. If you work out sick and something feels wrong - stop. Sure, working out might help you feel better when you have a cold, but it's not worth it to push yourself too hard and risk getting yourself really ill.
* Note: Think you're coming down with something? Consider your fellow athletes before bringing it to the gym and contributing to the germ cesspool.