The good news about exercise just keeps on coming. Solid evidence now indicates that regular, gentle exercise such as walking, bike riding, and aerobics helps you avoid the common cold. On those rare occasions when you do get sick, you will get over it faster if you are in the habit of walking or biking on a regular basis.
Moderate exercise boosts your immune system by increasing the number of white blood cells available to attack invading organisms. Although your white blood cell count returns to normal within hours of exercising, the temporary boost is enough to help cleanse your body of intruders.
If you’re already suffering with a head cold, an easy walk can ease your symptoms. But if you have a fever, diarrhea, vomiting, coughing, or body aches, exercising can put too much stress on an already stressed system and make things worse. In this case, be sure to give your body what it needs most—rest and plenty of fluids.