There is an old saying that you should “sweat out a cold,” but that’s just folk wisdom, not science. If you just have a runny nose or sore throat, it may be fine to do some moderate exercise for a half hour or so. But if you're achey and have a fever, then it's better to rest.
D:On today's A Moment of Science...[DON IS SUDDENLY INTERRUPTED BY A FIT OF COUGHING]
Y:Are you OK, Don?
D:Sorry, Yaël. I just have a cold. Nothing a little exercise can't fix.
Y:Wait--you're going to exercise even though you're not feeling well?
D:Sure. When I'm a little under the weather I try to work up a sweat, and then I usually feel better. You know the old saying about "sweating out a cold?"
Y:Yes, but that's just folk wisdom, not science. Let me ask: do you have a head cold, or do you maybe have a fever?
D:I'm not sure. I might feel a little warm.
Y:I ask because if you just have a runny nose or sore throat, it may be OK to do some moderate exercise for a half hour or so. But if you're achey and have a fever, then it's better to rest.
D:I guess that makes sense. It's just that I've heard that regular physical activity can strengthen your immune system and help prevent catching colds and other illnesses. So I figured that even if you're already sick, doing something physical may help.
Y:Well, again, it might, but it depends on how sick you are. In some cases, like if you have a fever, working out can tax your body and make the illness worse. So you need to rest to regain strength. And when you're coming out of a really bad cold or fever, it's best to ease back into exercise instead of jumping right back in.
D:Thanks for the advice. I'm gonna go take my temperature.
Y:Good idea.
