Exercise More, Sneeze Less

As the cold and flu season kicks into high gear this winter, it's good to know that regular exercise may be your first line of defense.

Although there has been some debate about the effects of exercise on immunity, a new study suggests that being active may actually reduce the number of colds people get each year.

Researchers from the University of South Carolina in Columbia surveyed 547 healthy adults at regular intervals over the course of one year.

Participants noted both their activity levels and the number of colds they had experienced. For this study, moderate or vigorous exercise was defined as anything more strenuous than a walk, including household chores and leisure activities.

The average adult will suffer through two to five colds per year. However, study participants who reported being most active had 25 percent fewer colds than those who were the least active.

The caveat to this study is that previous research has demonstrated that too much or too little exercise can have an adverse effect on the immune system, which could up one's risk of developing a cold.

Marathon runners, for example, appear to be more likely to develop a cold in the week immediately following a race than non-runners.

The key is to strike the right balance between exercise, good nutrition and adequate sleep.

Source: Medicine & Science in Sports & Exercise, 2002; 34, 1242-1248