If your symptoms are below the neck (chest congestion, intense coughing, vomiting, diarrhea), let your illness run its course before you start running again. Running under those conditions increases dehydration and may cause more serious issues. You also should never run if you have a high fever. And if your doctor advises you not to run, definitely listen to him or her.
Take off the next few days until you're feeling better. And, don't worry, you won't lose much fitness. You'll be back where you left off in no time.
If you're dealing with an illness that keeps you from running for two weeks or more, find out what to do when you take a break from running.More FAQs for Beginner Runners:

