The common cold doesn't have to keep you on the sidelines. Mild to moderate exercise is usually OK if your symptoms are all above the neck, such as a runny nose, nasal congestion, sneezing or minor sore throat. However, if your symptoms are below the neck, such as chest congestion, a hacking cough or upset stomach, delay your workout. And don't exercise if you have a fever, fatigue or widespread muscle aches.