Staying Active May Help Ease the Sniffles

< Nov. 03, 2010 > -- When you feel a cold coming on this winter, you might want to lace on your running shoes. A new study suggests that people who exercise regularly seem to have milder colds – and fewer of them.

"The physically active always brag that they're sick less than sedentary people," says lead researcher David C. Nieman, Dr.PH., director of the Human Performance Laboratory at the Appalachian State University, North Carolina Research Campus, in Kannapolis, N.C. "Indeed, this boast of active people that they are sick less often is really true."

For the study, published in this week’s online edition of the British Journal of Sports Medicine, researchers tracked 1,002 men and women ages 18 to 85. Over 12 weeks in the autumn and winter of 2008, the researchers recorded how many upper respiratory tract infections the participants had.

In addition, the participants reported how much and what kinds of aerobic exercise they did each week and rated their own fitness levels. They were asked about their lifestyle, dietary patterns, and stressful events, all of which can affect the immune system.

Fewer colds

The researchers found that the frequency of colds among people who exercised five or more days a week was about 46 percent less than those who were exercised no more than one day a week.

In addition, the number of days that people suffered cold symptoms was 41 percent lower among those who were physically active on five or more days of the week, compared with the largely sedentary group.

Colds also appeared to be less severe for those in better shape. Among those who felt the fittest, the severity of symptoms dropped by 32 to 41 percent among those who exercised most.

Related factors

The study did not adjust for all variables that might affect outcome, such as exposure to cold viruses at work or from children at home, the researchers say. But the study did account for age, body mass index, and education, and after taking those factors into account, the researchers found that being older, male, and married reduced the frequency of colds. Besides advancing age, however, the most significant factors were perceived fitness level and the amount of exercise.

Nieman says that one explanation for the study results could be that exercise activates the immune system at a higher rate than normal and causes immune cells to attack viruses.

This effect happens each time you exercise, and then the immune system returns to normal until you exercise again, Nieman says. "Any aerobic exercise should give you these immune benefits," he says.

Ah-Choo: Staying Cold-Free

A cold virus can be spread by touching the wet discharge from an infected person’s nose or mouth and then touching your eyes or nose, the National Institute of Allergy and Infectious Diseases says. It also can be spread when a person sneezes or coughs, which sends particles into the air that are then inhaled by another person.

Severe colds are spread more easily than mild ones because a greater amount of virus is passed into the air by coughing and sneezing. Thus, to hinder the spread of cold viruses, you should smother coughs, sneezes, and "nose-blows" with clean handkerchiefs or facial tissues. You should also wash viruses off your hands with soap and water and disinfect your surroundings.

If soap and water are not available, use an alcohol-based hand sanitizer to clean your hands. When using these products:

Apply the gel to the palm of one hand

Rub your hands together

Rub the product over all surfaces of your hands and fingers until they are dry

Damp, cold, or drafty weather does not increase the risk of getting a cold. According to most cold researchers, cold temperatures or bad weather simply brings people together indoors, which leads to more person-to-person contact.

Always talk with your doctor for more information.