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.
“We’ve always theorized that people who are physically active are sick less often than sedentary people,” explains Dyanne P. Westerberg, DO, Chief of Family and Community Medicine at Cooper University Hospital. “This new study suggests this is true, and provides one more great reason why people should exercise regularly.”
The study, published recently in the online edition of the British Journal of Sports Medicine, tracked 1,002 men and women ages 18 to 85. Over a 12-week period, the researchers recorded how many upper respiratory tract infections the participants had. In addition, the participants reported the duration and type 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 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 percent 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.
Dr. Westerberg agrees with the researchers, who say 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, Dr. Westerberg explains. “Any aerobic exercise should give you these immune benefits,” she says.
Tips for Staying Cold-Free
According to Dr. Westerberg, the best way to stay cold-free this season is to avoid people who are sick, and wash your hands often with antibacterial soap or use hand sanitizer. “Our hands pick up so many germs throughout the day,” explains Dr. Westerberg. “Taking a few minutes to wash hands or apply hand sanitizer can really help prevent the nuisance of having a cold.”