Illustration for an article titled, 'Is it OK to go for a run when I have a cold?' Answer: Running when you have a cold is usually fine, unless you have a fever, in which case you should stay in. In fact, there's evidence that running can improve circulation and reduce stress, which boosts the immune system, so a run may help improve your symptoms. Take extra care to stay hydrated and dress appropriately when you go out. 30 x 20, mixed media.