We've all been encouraged at one time or another to exercise, and for good reason. Besides maintaining a normal body weight, exercise has numerous health benefits, including reducing your risk for heart disease, clearing the mind, and even improving our emotional state.

Now health experts believe that people who get plenty of exercise, and as a result are more physically fit, also come down with fewer colds. Even when they do, they experience milder symptoms. The findings, published in the British Journal of Sports Medicine, are the result of a study that followed 1,000 adults who were up to the age of 85 years.

The subjects were 60% women and 40% men, with 40% between the ages of 18 and 39 years, 40% middle-aged, and 25% 60 years of age or older. Information was gathered regarding their level of aerobic activity as well as their fitness level according to a specialized scoring system. They subjects were also asked about their lifestyle choices, diet, as well as the number of stressful events in their lives. All of these factors are thought to have an influence on a person's immune system.

Over the course of 12 weeks, researchers tracked the respiratory health of these individuals during the autumn and winter months. The average number of days that the subjects came down with colds was varied depending on the season, with an average of 13 days in the winter and 8 days in the fall.

While being an older, married male seemed to reduce the risk for catching a coold, the most significant factor, after accounting for other variables, was the level of perceived fitness and the amount of exercise a person took part in. When people were physically active, corresponding to five or more days each week of exercise, they reported having half the number days feeling sick compared to people who exercised only one day or less each week.

In terms of the impact of their symptoms, people who felt the most fit experienced a 41% reduction in severity, while those who were the most active saw a 31% reduction. The reason that exercise may help to reduce a the severity and frequency of a cold is because it results in a temporary jump in the immune cells circulating in the body. Though these numbers drop down to normal levels within hours after exercise is stopped, exercising continuously may have a preventative effect when a person is exposed to infectious pathogens.

In this country, it has been estimated that an average adult will get a cold two to four times each year. For children, that number increases to six to 10 times. If you have questions or concerns, speak with your doctor. For more information, visit the websites for the Center for Disease Control and Prevention (CDC) and the National Library of Medicine.

Before engaging in any strenuous exercise, know your limits. Speak with your doctor or a fitness expert to design a regimen that is appropriate for your abilities.