Regular aerobic exercise could be a potent way to avoid getting the sniffles.
The average American fights the common cold two to four times a year. Many take a preemptive approach to the problem. They wash their hands frequently, avoid people who are sick, and walk around the block a few times.
Walk around the block?
Researchers suggest two possible explanations for why exercise may ward off colds. Walking temporarily increases counts of leukocytes (disease-fighting immune cells). Exercise may also increase levels of IGA (an antibody) in saliva, which is associated with a reduced risk of upper respiratory infections.