Mild to moderate physical activity is usually OK if you have a common cold and no fever. Exercise may even help you feel better by opening your nasal passages and temporarily relieving nasal congestion.

As a general guide for exercise and illness, consider this:

• Exercise is usually OK if your symptoms are all "above the neck." These signs and symptoms include those you may have with a common cold, such as a runny nose, nasal congestion, sneezing or minor sore throat.

  Consider reducing the intensity and length of your workout. Instead of going for a run, take a walk, for example.

• Don't exercise if your signs and symptoms are "below the neck," such as chest congestion, a hacking cough or upset stomach.
• Don't exercise if you have a fever, fatigue or widespread muscle aches.

Let your body be your guide. If you feel miserable, take a break. A few days off from exercise when you're sick shouldn't affect your performance. Resume your normal workout routine gradually as you begin to feel better. Check with your doctor if you aren't sure if it's OK to exercise.

If you do choose to exercise when you're sick, reduce the intensity and length of your workout. If you attempt to exercise at your normal intensity when you have more than a simple cold, you could risk more-serious injury or illness.