What is it about summer that keeps people relatively free of colds? The answer may be that people spend time outdoors and engage in more physical activity.

What happens during the winter? People do the exact opposite. They spend nearly all of their time indoors in well-heated buildings and are relatively inactive. Could this more sedentary lifestyle be setting them up for getting a cold?

Every September, I hear many of my friends tell me they’re hanging up their bikes and putting away their sporting gear because of shorter days and cooler weather. I keep telling them that if they want to fight off germs during the cold and flu season they need to stay physically active and continue getting outside as much as possible.

The secret to staying healthy during the fall and winter is keeping your immune system functioning at the top of its game by engaging in regular, moderate exercise. Exercise is a “win/win” situation for your immune system that makes getting off the couch definitely worth the effort.

Consider the many benefits of just 30 minutes of exercise a day. Exercise releases mood-elevating endorphins which makes your feel better. It moderates the effects of stress, and individuals who exercise regularly are less likely to get sick after stressful situations. Better sleep is another benefit of regular exercise.

Physical activity helps the cardiovascular system, improves blood flow, flushes away toxins from muscles and organs, and helps keep the kidneys and endocrine system working well. It removes germs and circulates antibodies. The body’s temperature is raised during exercise which helps kill infecting organisms.

Over time, this means catching fewer colds and other respiratory infections. Studies have shown that individuals who engage in regular aerobic activities are less prone to colds and flu that affect a large percentage of the population. If you do get a bug, you're more likely to recover faster.

Combine adequate sleep and good nutrition with exercise and your immune system gets an extra power punch to fight off germs. Munch on plenty of fruits and vegetables to strengthen your immune system.

Finding more reasons to laugh during cold season may give your immune system an additional boost. You may end up doing less coughing, sniffling and sneezing. Laughter increases the body’s capacity to fight disease. Laughter reduces stress, lowers blood pressure, elevates mood, relaxes you and makes you feel good.

Here’s your prescription for a healthier you this cold season: exercise, eat right, get enough sleep and laugh. Isn’t that what your mother taught you?